This research aims to develop a wound dressing composed of collagen (Col) and hyaluronic acid (HA) containing epidermal growth factor (EGF). First important issue is to contain EGF in the wound dressing in a stable st...This research aims to develop a wound dressing composed of collagen (Col) and hyaluronic acid (HA) containing epidermal growth factor (EGF). First important issue is to contain EGF in the wound dressing in a stable state. The sheet-shaped sponge was manufactured by freeze-vacuum drying an aqueous solution of Col. Both sides of sponge were treated with ultraviolet (UV) irradiation to introduce intermolecular cross links between collagen molecules. This sponge was named Sponge-Col. Another sheet-shaped sponge was manufactured by freeze-vacuum drying an aqueous solution of HA containing EGF. This sponge was named Sponge-HA/EGF. The wound dressing was manufactured by laminating Sponge-Col on the top, Sponge-HA/EGF in the middle, and Sponge-Col on the bottom to create a sandwich structure. This method can prevent the reducing of EGF activity due to UV irradiation for intermolecular cross-linking. Second important issue is to enable gradual release of EGF from the wound dressing. The elution behavior of this wound dressing was investigated by measuring the weight change after immersion in water for a predetermined time. This wound dressing showed initially fast elution and subsequent very slow elution properties. The upper layer and lower layer Sponge-Col enabled gradual release of the middle layer Sponge-HA/EGF. This result suggests that EGF contained in the wound dressing is gradually released together with HA from the wound dressing. Third important issue is to provide moist wound-healing environment. The upper layer and lower layer Sponge-Col can provide the wound dressing with high water absorption and long-term water retention properties.展开更多
Polyurethane foam dressings for dermal wounds were formulated with natural polyols in order to improve the foam characteristics and the release of 2 active agents,silver and asiaticoside(AS)as an antimicrobial agent a...Polyurethane foam dressings for dermal wounds were formulated with natural polyols in order to improve the foam characteristics and the release of 2 active agents,silver and asiaticoside(AS)as an antimicrobial agent and an herbal wound healing agent,respectively.The foam was instantly formed by interaction of polyols and diisocyanate.Hydroxypropyl methylcellulose,chitosan and sodium alginate were individually mixed with themain polyols,polypropylene glycol,in the formulation while the active componentswere impregnated into the obtained foam dressing sheets.Although the type and amount of the natural polyols slightly affected the pore size,water sorption-desorption profile and compression strength of the obtained foam sheets,a prominent effect was found in the release of both active components.Among natural polyols formulations,foam sheets with alginate showed the highest silver and AS release.Non-cytotoxicity of these foam sheets to human fibroblast cells was confirmed.Antimicrobial testing on four bacteria strains showed that 1mg/cm^2 silver in formulations with 6%of natural polyols and without natural polyols had sufficient content of the silver release with comparable inhibition zone and significantly larger zone than other formulations.In pig study,the foam dressing with 6%alginate,1mg/cm^2 silver and 5%AS could improve wound healing in both the percentage of the wound closure and histological parameters of the dermal wound without any dermatologic reactions.In conclusion,this innovative foam dressing had potential to be a good candidate for wound treatment.展开更多
Background: Wounded personnel who work at sea often encounter a plethora of difficulties. The most important of these difficulties is seawater immersion. Common medical dressings have little effect when the affected a...Background: Wounded personnel who work at sea often encounter a plethora of difficulties. The most important of these difficulties is seawater immersion. Common medical dressings have little effect when the affected area is immersed in seawater, and only rarely dressings have been reported for the treatment of seawater-immersed wounds. The objective of this study is to develop a new dressing which should be suitable to prevent the wound from seawater immersion and to promote the wound healing.Methods: Shark skin collagen(SSC) was purified via ethanol de-sugaring and de-pigmentation and adjusted for p H. A shark skin collagen sponge(SSCS) was prepared by freeze-drying. SSCS was attached to an anti-seawater immersion polyurethane(PU) film(SSCS+PU) to compose a new dressing. The biochemical properties of SSC and physicochemical properties of SSCS were assessed by standard methods. The effects of SSCS and SSCS+PU on the healing of seawaterimmersed wounds were studied using a seawater immersion rat model. For the detection of SSCS effects on seawaterimmersed wounds, 12 SD rats, with four wounds created in each rat, were divided into four groups: the 3 rd day group, 5 th day group, 7 th day group and 12 th day group. In each group, six wounds were treated with SSCS, three wounds treated with chitosan served as the positive control, and three wounds treated with gauze served as the negative control. For the detection of the SSCS+PU effects on seawater-immersed wounds, 36 SD rats were divided into three groups: the gauze(GZ)+PU group, chitosan(CS)+PU group and SSCS+PU group, with 12 rats in each group, and two wounds in each rat. The wound sizes were measured to calculate the healing rate, and histomorphology and the immunohistochemistry of the CD31 and TGF-β expression levels in the wounded tissues were measured by standard methods.Results: The results of Ultraviolet-visible(UV-vis) spectrum, Fourier-transform infrared(FTIR) spectrum, circular dichroism(CD) spectra, sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE), and amino acid composition analyses of SSC demonstrated that SSC is type I collagen. SSCS had a homogeneous porous structure of approximately 200μm, porosity rate of 83.57%±2.64%, water vapor transmission ratio(WVTR) of 4500 g/m2, tensile strength of 1.79±0.41 N/mm, and elongation at break of 4.52%±0.01%. SSCS had significant beneficial effects on seawater-immersed wound healing. On the 3 rd day, the healing rates in the GZ negative control, CS positive control and SSCS rats were 13.94%±5.50%, 29.40%±1.10% and 47.24%±8.40%, respectively. SSCS also enhanced TGF-in the initial stage of the healing period. The SSCS+PU dressing effectively protected woundsβ and CD31 expression from seawater immersion for at least 4 h, and accelerated re-epithelialization, vascularization and granulation formation of seawater-immersed wounds in the earlier stages of wound healing, and as well as significantly promoted wound healing. The SSCS+PU dressing also enhanced expression of TGF-n and gauze dressings.β and CD31. The effects of SSCS and SSCS+PU were superior to those of both the chitosaConclusion: SSCS has significant positive effects on the promotion of seawater-immersed wound healing, and a SSCS+PU dressing effectively prevents seawater immersion, and significantly promotes seawater-immersed wound healing.展开更多
Bacterial infection and the ever-increasing bacterial resistance have imposed severe threat to human health.And bacterial contamination could significantly menace the wound healing process.Considering the sophisticate...Bacterial infection and the ever-increasing bacterial resistance have imposed severe threat to human health.And bacterial contamination could significantly menace the wound healing process.Considering the sophisticated wound healing process,novel strategies for skin tissue engineering are focused on the integration of bioactive ingredients,antibacterial agents included,into biomaterials with different morphologies to improve cell behaviors and promote wound healing.However,a comprehensive review on antibacterial wound dressing to enhance wound healing has not been reported.In this review,various antibacterial biomaterials as wound dressings will be discussed.Different kinds of antibacterial agents,including antibiotics,nanoparticles(metal and metallic oxides,lightinduced antibacterial agents),cationic organic agents,and others,and their recent advances are summarized.Biomaterial selection and fabrication of biomaterials with different structures and forms,including films,hydrogel,electrospun nanofibers,sponge,foam and three-dimension(3D)printed scaffold for skin regeneration,are elaborated discussed.Current challenges and the future perspectives are presented in thismultidisciplinary field.We envision that this review will provide a general insight to the elegant design and further refinement of wound dressing.展开更多
With the changes in the modern disease spectrum,pressure ulcers,diabetic feet,and vascular-derived diseases caused refractory wounds is increasing rapidly.The development of wound dressings has partly improved the eff...With the changes in the modern disease spectrum,pressure ulcers,diabetic feet,and vascular-derived diseases caused refractory wounds is increasing rapidly.The development of wound dressings has partly improved the effect of wound management.However,traditional wound dressings can only cover the wound and block bacteria,but are generally powerless to recurrent wound infection and tissue healing.There is an urgent need to develop a new type of wound dressing with comprehensive performance to achieve multiple effects such as protecting the wound site from the external environment,absorbing wound exudate,anti-inflammatory,antibacterial,and accelerating wound healing process.Hydrogel wound dressings have the aforementioned characteristics,and can keep the wound in a moist environment because of the high water content,which is an ideal choice for wound treatment.This review introduces the wound healing process and the development and performance advantages of hydrogel wound dressings.The choice of different preparation materials gives the particularities of different hydrogel wound dressings.It also systematically explains the main physical and chemical crosslinking methods for hydrogel synthesis.Besides,in-depth discussion of four typical hydrogel wound dressings including double network hydrogels,nanocomposite hydrogels,drug-loaded hydrogels and smart hydrogels fully demonstrates the feasibility of developing hydrogels as wound dressing products and their future development trends.展开更多
A series of hydrogels with different ratios of chitosan and licorice polysaccharide(LP)were prepared by crosslinking to different concentrations of genipin(gp).They were characterized by FTIR(Fourier transform infra...A series of hydrogels with different ratios of chitosan and licorice polysaccharide(LP)were prepared by crosslinking to different concentrations of genipin(gp).They were characterized by FTIR(Fourier transform infrared spectroscopy),SEM(Scanning electron microscope),swelling ratio,rheological measurements,degradation with time,cytotoxicity,and antibacterial efficacy.Results show that the hydrogels have porous structures.With an increase in LP content,the swelling rate grows in the early stage of immersion in buffer and drops later.The swelling ratio ranged from 986%to 1677%,and stiffness varied from 777 Pa to 1792 Pa.The addition of LP reduced the mechanical strength and delayed gelation and degradation of the hydrogels.However,the most important discovery was that gp increases the viability of NIH 3T3 cells from 94%to 137%,and LP raises the bacteriostatic efficacy from 51%to 78%.Hydrogels synthesized from 1%genipin,3%chitosan,and 4%licorice polysaccharide showed the best antibacterial and fibroblast proliferation promoting activities.They exhibited moderate swelling and degradation rates over time,while being more suitable to affect healing of chronic wound infections.These results provide a new strategy to improve the antibacterial effectiveness and cyto-compatibility of chitosan hydrogels with water soluble active LPs from Glycyrrhiza that derive from traditional Chinese medicine.展开更多
The variety of wound types has resulted in a wide range of wound dressings, with new products frequently being introduced to target different aspects of the wound healing process. The ideal wound dressing should achie...The variety of wound types has resulted in a wide range of wound dressings, with new products frequently being introduced to target different aspects of the wound healing process. The ideal wound dressing should achieve rapid healing at a reasonable cost, with minimal inconvenience to the patient. Microcurrent dressing, a novel wound dressing with inherent electric activity, can generate low-level microcurrents at the device-wound contact surface in the presence of moisture and can provide an advanced wound healing solution for managing wounds. This article offers a review of the effects and mechanisms of the microcurrent dressing on the healing of skin wounds.展开更多
Background: The value of periodontal dressing and its effects on periodontal wound healing have been questioned. Besides, the early healing of the gingival and periodontal wounds in oral cavity should be emphasized to...Background: The value of periodontal dressing and its effects on periodontal wound healing have been questioned. Besides, the early healing of the gingival and periodontal wounds in oral cavity should be emphasized to promote the treatment outcome. Several studies pointed out a potential positive effect of silver nanoparticles (NPs) on the healing process of skin wounds. The present work aimed to design silver NPs periodontal dressing and then, evaluated its effects on gingival wound healing following operation. Methods: Thirty healthy adolescent female rabbits were used in this study. They had intact teeth and the clinical and radiographic examination revealed no periodontal disease. Silver NPs were added to carbonate methyl cellulose as base with two different concentrations of 25% v/v (Group A) and 50% v/v (Group B). On the basis of simple randomized allocation, gingivectomy was performed at the buccal gingiva of the left and right mandibular incisors and subsequently, untreated wounds in the control area were covered with periodontal pack and periodontal dressings A and B were applied in the test regions. Histological changes were monitored in day 4 and 7 post operation to evaluate the inflammatory and repair stage of healing process. Results: We observed significant difference in the inflammatory and repair parameters of the healing process between surgical sites treated with this periodontal dressing and control group. Besides, wounds treated with silver NPs dressing in general terms had all the hallmarks of relatively complete healing one week post operatively. Conclusion: The results indicated positive potential therapeutic effects for this new formulation of periodontal dressing on acceleration of surgical wound healing that led to improvement of periodontal treatment consequences following operation.展开更多
A number of materials are utilized to develop wound care dressing materials with metallic treatments such as ionic silver and zinc. Metallic ions if used for a prolonged time may lead to toxicity. Alternatively chitin...A number of materials are utilized to develop wound care dressing materials with metallic treatments such as ionic silver and zinc. Metallic ions if used for a prolonged time may lead to toxicity. Alternatively chitin,a natural polysaccharide found in nature, is utilized. It is found in fungi, crabs, mushrooms,squids, octopus, and many other living organisms. Chitin has similar structure to cellulose but its deacetylated derivate chitosan has amine groups that provide potential antibacterial properties along with a number of other advantages. Chitin in its natural form is found in three different structural forms,namely α,β,and γ.The β-chitin and chitosan are mostly found in the exoskeleton of squids. Loligo and Humboldt squids were studied. It is anticipated that Humboldt chitin is more effective in serving as antibacterial material and can be utilized for wound care. Differences in steriochemical structure were observed among β-chitin structures obtained and amine group's presences were found along with ability of materials to swell.展开更多
The main objective of this research work was the development of novel and responsive nonwoven composite structures containing gelling materials for wound management. The development of novel all inclusive collagen boo...The main objective of this research work was the development of novel and responsive nonwoven composite structures containing gelling materials for wound management. The development of novel all inclusive collagen booster(CB) therapeutic nonwoven wound dressings was mainly focused on. It provides essential functional properties such as high absorption,vertical and lateral wicking,and antibacterial and acidic pH properties. The developed composite wound dressing consisted of carboxymethylcellulose(CMC) fibre and also it was reinforced with polylactic acid( PLA) fibre. The produced composite wound dressings were treated with two different CBs at 4% by using the spray method. The details of the CBs have not been disclosed in this paper due to the Intellectual Property Rights( IPR) issues. The important benefit of using CB treatment is that it allows the maintenance of an acidic pH environment at the wound area. It is well known that acidic pH reduces the wound healing time and enhances the wound healing process. Furthermore,one of the CBs not only promotes the proliferation of the epithelial cells in wounds but also can provide antibacterial action. The PLA fibre reinforced CMC composite dressing has enhanced wicking properties which help to minimise the pooling of exudate on the wound bed and as a result maceration is prevented. The CBs treated dressings maintain the wound bed in an acidic pH condition which also improves the wound healing process. In addition to the above-mentioned properties,the CB treatment imparts antimicrobial activity against Gram-positive and Gram-negative bacteria,thus resulting in the reduction in the propensity for wound infection. Ultimately,the research has proved that the 4% CB treatment enhances the antimicrobial activity and the acidic pH characteristics of the developed CMC /PLA composite wound dressings.展开更多
Collagen(Col)/chitosan(CS)nanofibrous membrane has great potential to be used as wound dressing.However,current Col/CS nanofibrous membrane produced from electrospinning can not offer sufficient mechanical strength fo...Collagen(Col)/chitosan(CS)nanofibrous membrane has great potential to be used as wound dressing.However,current Col/CS nanofibrous membrane produced from electrospinning can not offer sufficient mechanical strength for practical applications.Herein,a novel mixed solvent was used to prepare next-generation high-strength Col/CS nanofibrous membrane.Meanwhile,the optimal Col to CS weight ratio was investigated as well.The asproduced membrane was examined by scanning electron microscopy(SEM),attenuated total reflectance Fourier transform infrared spectroscopy(ATR-FTIR),differential scanning calorimetry(DSC),and XF-1A tester to study its morphological,chemical,thermal and mechanical properties.The preliminary results demonstrated that the mechanical properties of Col/CS nanofibrous membranes were enhanced substantially with the increase of CS weight ratios from 0 to 90%and the optimal Col to CS weight ratio was determined to be 1∶1.A promising way was presented to fabricate Col/CS electrospun nanofibrous membrane with sufficient mechanical strength for practical wound dressing applications.展开更多
To obtain the wound dressings which can accelerate healing effectively,vitamin E D-α-Tocopherol polyethylene glycol succinate(vitamin E TPGS),one of the common derivatives of the unstable vitamins E,was successfully ...To obtain the wound dressings which can accelerate healing effectively,vitamin E D-α-Tocopherol polyethylene glycol succinate(vitamin E TPGS),one of the common derivatives of the unstable vitamins E,was successfully incorporated into P(LLA-CL)nanofibers by electrospinning.Electron microscopy showed that the smooth cylindrical fibers were obtained,albeit with a small amount of beading visible for the vitamins-loaded fibers.The diameters of the P(LLA-CL)fibers decreased with the addition of vitamins.The incorporation of the vitamin E TPGS in the electrospun fibers was confirmed by Fourier transform infrared spectroscopy(FTIR).Moreover,X-ray diffraction(XRD)indicated that vitamin E TPGS existed in the amorphous physical form after electrospinning.Fibers containing vitamin E TPGS showed a sustained release profile over more than 100 h in vitro.Antibacterial tests demonstrated that fibers loaded with vitamin E TPGS were effective in inhibiting the growth of E.coli and S.aureus.MTT assay showed that the fibers could promote the proliferation of L929 fibroblasts.These results above demonstrate the potential of P(LLA-CL)/vitamins E TPGS(P/E)as advanced wound dressing materials.展开更多
Objective:Research on the effect of moist wound healing theory in a combination with modern new dressing treatment in patients diagnosed with pressure ulcers.Method:Selected 30 patients with pressure ulcers from our h...Objective:Research on the effect of moist wound healing theory in a combination with modern new dressing treatment in patients diagnosed with pressure ulcers.Method:Selected 30 patients with pressure ulcers from our hospital,which is Shandong Tai an Municipal Hospital,from January 2019 to January 2021 were divided into experimental group(15 cases,treated with moist wound healing theory combined with modern new dressings)and control group(15 cases,applied conventional treatments).The treatment effect,time of wound edema subsidence,wound healing time,number of dressing changes,granulation tissue growth time,and diameter reduction time were compared between the two groups.Results:The total effective rate of the experimental group(93.33%,14/15)was higher than that of the control group(53.33%,8/15),P<0.05;the time to subsidence of wound edema in the experimental group was(3.11±0.22),and the time for wound healing was(12.78±0.45),the number of dressing changes(7.13±0.34)times,the growth time of granulation tissue(5.43±2.22),the diameter reduction time(6.25±3.75),compared with the control group,P<0.05.Conclusion:In the clinical treatment of patients diagnosed with pressure ulcers,the effective combination of moist healing theory and modern new dressing therapy has significant effects,whereby it speeds up the healing process of the pressure ulcers,and it is proven to be worthy to be promoted for usage.展开更多
Background:The exogenous application of low-intensity electric stimulation(ES)may mimic a natural endogenous bioelectric current and accelerate the repair process of skin wounds.This study designed a novel microcurren...Background:The exogenous application of low-intensity electric stimulation(ES)may mimic a natural endogenous bioelectric current and accelerate the repair process of skin wounds.This study designed a novel microcurrent dressing(MCD)and evaluated its potential effects on wound healing in a rat skin defect model.Methods:First,wireless ES was integrated into a medical cotton cushion to fabricate the MCD,and its electrical property was examined by using a universal power meter.Then,animal experiments were conducted to evaluate the MCD’s effect.Forty-five rats were randomized into control(Con)group,Vaseline gauze(VG)group and MCD group.A full-thickness round skin incision 1.5 cm in diameter was made on the back of each animal.Apart from routine disinfection,the Con rats were untreated,whereas the other two groups were treated with VG or MCD.On days 3,7 and 14 post injury,the wound areas were observed and measured using image analysis software following photography,and the skin samples were harvested from wound tissue.Then,histopathological morphology was observed routinely by hematoxylin and eosin(HE)staining;tumor necrosis factorα(TNF-α)and interleukin(IL)-1βexpression were detected by Western blotting.Vascular endothelial growth factor(VEGF)and epidermal growth factor(EGF)expression were detected with immunohistochemistry.Results:The MCD generated a sf electric potential greater than 0.95 V.Animal experiments showed that the woundhealing rate in the MCD group was significantly increased compared with the Con and VG groups(P<0.05 or P<0.01).Histopathological observation revealed an alleviated inflammatory response,induced vascular proliferation and accelerated epithelization in the MCD group.Moreover,samples from the MCD group expressed reduced TNF-αand IL-1βlevels and increased VEGF and EGF levels compared with those of the other two groups(P<0.05 or P<0.01).However,no significant difference was noted between the Con and VG groups at each time point.Conclusions:The MCD generates a stable and lasting ES and significantly promotes wound healing by reducing inflammation duration and increasing growth factors expression.Thus,MCD may act as a promising biomaterial device for skin wound healing.展开更多
Although the treatment of burn wounds has made great progress, the incidence of wound infection is still the main cause of high mortality. In this study, a silk fibroin (SF) scaffold wound dressing incorporated with G...Although the treatment of burn wounds has made great progress, the incidence of wound infection is still the main cause of high mortality. In this study, a silk fibroin (SF) scaffold wound dressing incorporated with Gentamicin Sulfate (GS) was developed for the treatment of burn infected wounds, in which GS was used as anti-bacterial agent. GS was mixed with silk fibroin solution and then processed into GS-SF composite scaffold via electro-spinning. The results showed the scaffold exhibited uniform polyporous morphology with 80% porosity. Induced by methanol, the scaffold presented much improved mechanical properties and stability to protease <em>XIV</em>. More important, the scaffold presented significant growth inhibition on both Gram-positive (<em>Staphylococcus aureus</em>) and Gram-negative (<em>Pseudomonas aeruginosa and Escherichia coli</em>) bacteria.展开更多
There is currently no consensus regarding the management of acute cutaneous reactions emerging from a concurrent treatment of radio-and chemotherapy, the goal of this case study series is to provide scientific evidenc...There is currently no consensus regarding the management of acute cutaneous reactions emerging from a concurrent treatment of radio-and chemotherapy, the goal of this case study series is to provide scientific evidence based on clinical practice regarding the efficacy of a film-forming wound dressing for patients receiving combined cancer therapy, in particular examples where the reactions are expected to be intense. In all the described cases, management of acute skin reactions allowed the cancer therapy to be finalized, instead of being interrupted due to an increase in the severity of the reactions. It has been shown in the current literature that the lack of compliance with treatment plans correlates with poorer clinical outcome. Evidence from the cases presented suggest that the studied dressing is safe and efficacious in the treatment and the prevention of acute cutaneous reactions arising from combined cancer therapy.展开更多
A silk fibroin(SF)spongy wound dressing incorporated with silver nanoparticles(Ag-NPs)was developed for biomedical applications.Ag-NPs were efficiently synthesized in situ via ultra violet(UV)with AgNO_(3) as precurso...A silk fibroin(SF)spongy wound dressing incorporated with silver nanoparticles(Ag-NPs)was developed for biomedical applications.Ag-NPs were efficiently synthesized in situ via ultra violet(UV)with AgNO_(3) as precursor and silk fibroin as reducing and protecting agent,respectively.After lyophilization,the formed silk fibroin spongy wound dressing(SFWD)exhibited polyporous morphology and inner lamellae structures,with uniform dispersion of Ag-NPs.The porous structure provided SFWD with the ability to absorb tissue exudatealmost 6 times of its own weight,which could guarantee the sustained release of Ag-NPs.By methanol treatment,SFWD showed much improved mechanical properties and more stable to protease XIV.The cyto-compatibility of SFWD was supported by normal adherence and proliferation of NIH3T3 fibroblasts in sponges extracting culture medium.More important,the SFWD showed significant growth inhibition in both plate culture assays and bacterial suspension assays,with Gram-positive(Staphylococcus aureus)and Gram-negative(Pseudomonas aeruginosa and Escherichia coli).In a cutaneous excisional mouse model,the average healing rates of SFWD was significantly higher than control and commercial bandages.The hematoxylin-eosin(HE)staining results of the wound section also showed that SFWD could recruit more cells and promote tissue formation on the wound edges.展开更多
A porous,biocompatible,and modifiable chitosan (CS)/poly (vinyl alcohol) (PVA) hybrid membrane, which can be evaluated as wound dressing,has been prepared by lyophilization method and using the low toxicity solvents. ...A porous,biocompatible,and modifiable chitosan (CS)/poly (vinyl alcohol) (PVA) hybrid membrane, which can be evaluated as wound dressing,has been prepared by lyophilization method and using the low toxicity solvents. Experiments illustrated that the moisture regain and porosity rate of polymer blend membranes had the similar variation tendency and got the maximum value at the case of CS/PVA weight ratio of 6∶4. And the value of water vapor transmission rate( WVTR) is conductive to the healing of wound and desirable for the application as a wound dressing.Mechanical performance test of blend membrane showed that the presence of PVA could effectively improve the interaction between CS molecules. The scanning electron microscopy( SEM)photograph confirmed the porous surface on top-layer supported by a macroporous sponge-like sub-layer of this novel type of CS blend membrane. Besides, Fourier transform infrared spectroscopy( FTIR) revealed the facts that the two polymers were physically bended and certain chemical actions took place,which illustrated the good compatibility between them. Differential scanning calorimetry(DSC) results showed that decomposition reaction occurred in CS at about 210℃. Introducing of PVA to CS made the decomposition temperature of blend membrane decrease. The good properties,such as moisture regain,porosity rate,and WVTR,of this kind of CS/PVA blend membranes suggested a potential application as a wound dressing in the future.展开更多
文摘This research aims to develop a wound dressing composed of collagen (Col) and hyaluronic acid (HA) containing epidermal growth factor (EGF). First important issue is to contain EGF in the wound dressing in a stable state. The sheet-shaped sponge was manufactured by freeze-vacuum drying an aqueous solution of Col. Both sides of sponge were treated with ultraviolet (UV) irradiation to introduce intermolecular cross links between collagen molecules. This sponge was named Sponge-Col. Another sheet-shaped sponge was manufactured by freeze-vacuum drying an aqueous solution of HA containing EGF. This sponge was named Sponge-HA/EGF. The wound dressing was manufactured by laminating Sponge-Col on the top, Sponge-HA/EGF in the middle, and Sponge-Col on the bottom to create a sandwich structure. This method can prevent the reducing of EGF activity due to UV irradiation for intermolecular cross-linking. Second important issue is to enable gradual release of EGF from the wound dressing. The elution behavior of this wound dressing was investigated by measuring the weight change after immersion in water for a predetermined time. This wound dressing showed initially fast elution and subsequent very slow elution properties. The upper layer and lower layer Sponge-Col enabled gradual release of the middle layer Sponge-HA/EGF. This result suggests that EGF contained in the wound dressing is gradually released together with HA from the wound dressing. Third important issue is to provide moist wound-healing environment. The upper layer and lower layer Sponge-Col can provide the wound dressing with high water absorption and long-term water retention properties.
基金supported by the Yeungnam University research grant in 2017。
文摘Polyurethane foam dressings for dermal wounds were formulated with natural polyols in order to improve the foam characteristics and the release of 2 active agents,silver and asiaticoside(AS)as an antimicrobial agent and an herbal wound healing agent,respectively.The foam was instantly formed by interaction of polyols and diisocyanate.Hydroxypropyl methylcellulose,chitosan and sodium alginate were individually mixed with themain polyols,polypropylene glycol,in the formulation while the active componentswere impregnated into the obtained foam dressing sheets.Although the type and amount of the natural polyols slightly affected the pore size,water sorption-desorption profile and compression strength of the obtained foam sheets,a prominent effect was found in the release of both active components.Among natural polyols formulations,foam sheets with alginate showed the highest silver and AS release.Non-cytotoxicity of these foam sheets to human fibroblast cells was confirmed.Antimicrobial testing on four bacteria strains showed that 1mg/cm^2 silver in formulations with 6%of natural polyols and without natural polyols had sufficient content of the silver release with comparable inhibition zone and significantly larger zone than other formulations.In pig study,the foam dressing with 6%alginate,1mg/cm^2 silver and 5%AS could improve wound healing in both the percentage of the wound closure and histological parameters of the dermal wound without any dermatologic reactions.In conclusion,this innovative foam dressing had potential to be a good candidate for wound treatment.
基金supported by a Major Project of the Ministry of National Science and Technology of China(Grant No.2014ZX09J14103-09C).
文摘Background: Wounded personnel who work at sea often encounter a plethora of difficulties. The most important of these difficulties is seawater immersion. Common medical dressings have little effect when the affected area is immersed in seawater, and only rarely dressings have been reported for the treatment of seawater-immersed wounds. The objective of this study is to develop a new dressing which should be suitable to prevent the wound from seawater immersion and to promote the wound healing.Methods: Shark skin collagen(SSC) was purified via ethanol de-sugaring and de-pigmentation and adjusted for p H. A shark skin collagen sponge(SSCS) was prepared by freeze-drying. SSCS was attached to an anti-seawater immersion polyurethane(PU) film(SSCS+PU) to compose a new dressing. The biochemical properties of SSC and physicochemical properties of SSCS were assessed by standard methods. The effects of SSCS and SSCS+PU on the healing of seawaterimmersed wounds were studied using a seawater immersion rat model. For the detection of SSCS effects on seawaterimmersed wounds, 12 SD rats, with four wounds created in each rat, were divided into four groups: the 3 rd day group, 5 th day group, 7 th day group and 12 th day group. In each group, six wounds were treated with SSCS, three wounds treated with chitosan served as the positive control, and three wounds treated with gauze served as the negative control. For the detection of the SSCS+PU effects on seawater-immersed wounds, 36 SD rats were divided into three groups: the gauze(GZ)+PU group, chitosan(CS)+PU group and SSCS+PU group, with 12 rats in each group, and two wounds in each rat. The wound sizes were measured to calculate the healing rate, and histomorphology and the immunohistochemistry of the CD31 and TGF-β expression levels in the wounded tissues were measured by standard methods.Results: The results of Ultraviolet-visible(UV-vis) spectrum, Fourier-transform infrared(FTIR) spectrum, circular dichroism(CD) spectra, sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE), and amino acid composition analyses of SSC demonstrated that SSC is type I collagen. SSCS had a homogeneous porous structure of approximately 200μm, porosity rate of 83.57%±2.64%, water vapor transmission ratio(WVTR) of 4500 g/m2, tensile strength of 1.79±0.41 N/mm, and elongation at break of 4.52%±0.01%. SSCS had significant beneficial effects on seawater-immersed wound healing. On the 3 rd day, the healing rates in the GZ negative control, CS positive control and SSCS rats were 13.94%±5.50%, 29.40%±1.10% and 47.24%±8.40%, respectively. SSCS also enhanced TGF-in the initial stage of the healing period. The SSCS+PU dressing effectively protected woundsβ and CD31 expression from seawater immersion for at least 4 h, and accelerated re-epithelialization, vascularization and granulation formation of seawater-immersed wounds in the earlier stages of wound healing, and as well as significantly promoted wound healing. The SSCS+PU dressing also enhanced expression of TGF-n and gauze dressings.β and CD31. The effects of SSCS and SSCS+PU were superior to those of both the chitosaConclusion: SSCS has significant positive effects on the promotion of seawater-immersed wound healing, and a SSCS+PU dressing effectively prevents seawater immersion, and significantly promotes seawater-immersed wound healing.
基金supported by the National Natural Science Foundation of China (grant numbers: 51973172)Natural Science Foundation of Shaanxi Province (No. 2020JC03 and 2019TD-020)+2 种基金State Key Laboratory for Mechanical Behavior of Materials, and Opening Project of Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi’an Jiaotong University (No. 2019LHM-KFKT008)the World-Class Universities (Disciplines)the Characteristic Development Guidance Funds for the Central Universities
文摘Bacterial infection and the ever-increasing bacterial resistance have imposed severe threat to human health.And bacterial contamination could significantly menace the wound healing process.Considering the sophisticated wound healing process,novel strategies for skin tissue engineering are focused on the integration of bioactive ingredients,antibacterial agents included,into biomaterials with different morphologies to improve cell behaviors and promote wound healing.However,a comprehensive review on antibacterial wound dressing to enhance wound healing has not been reported.In this review,various antibacterial biomaterials as wound dressings will be discussed.Different kinds of antibacterial agents,including antibiotics,nanoparticles(metal and metallic oxides,lightinduced antibacterial agents),cationic organic agents,and others,and their recent advances are summarized.Biomaterial selection and fabrication of biomaterials with different structures and forms,including films,hydrogel,electrospun nanofibers,sponge,foam and three-dimension(3D)printed scaffold for skin regeneration,are elaborated discussed.Current challenges and the future perspectives are presented in thismultidisciplinary field.We envision that this review will provide a general insight to the elegant design and further refinement of wound dressing.
基金Authors acknowledged the funding supports from the National Key R&D Program of China(2019YFA0905200).
文摘With the changes in the modern disease spectrum,pressure ulcers,diabetic feet,and vascular-derived diseases caused refractory wounds is increasing rapidly.The development of wound dressings has partly improved the effect of wound management.However,traditional wound dressings can only cover the wound and block bacteria,but are generally powerless to recurrent wound infection and tissue healing.There is an urgent need to develop a new type of wound dressing with comprehensive performance to achieve multiple effects such as protecting the wound site from the external environment,absorbing wound exudate,anti-inflammatory,antibacterial,and accelerating wound healing process.Hydrogel wound dressings have the aforementioned characteristics,and can keep the wound in a moist environment because of the high water content,which is an ideal choice for wound treatment.This review introduces the wound healing process and the development and performance advantages of hydrogel wound dressings.The choice of different preparation materials gives the particularities of different hydrogel wound dressings.It also systematically explains the main physical and chemical crosslinking methods for hydrogel synthesis.Besides,in-depth discussion of four typical hydrogel wound dressings including double network hydrogels,nanocomposite hydrogels,drug-loaded hydrogels and smart hydrogels fully demonstrates the feasibility of developing hydrogels as wound dressing products and their future development trends.
基金This work was financially supported by the National Natural Science Foundation of China for support for this research(Nos.81560737 and 31860250)We also thank the Natural Science Foundation of Gansu Province through Grant 18JR3RA148+1 种基金the Fundamental Research Funds for Key Laboratory of Drug Screening and Deep Processing for Traditional Chinese and Tibetan Medicine of Gansu Province Grant(No.20180801)Distinguished Young Cultivation Project(No.JQ2020)of Lanzhou University of Technology.
文摘A series of hydrogels with different ratios of chitosan and licorice polysaccharide(LP)were prepared by crosslinking to different concentrations of genipin(gp).They were characterized by FTIR(Fourier transform infrared spectroscopy),SEM(Scanning electron microscope),swelling ratio,rheological measurements,degradation with time,cytotoxicity,and antibacterial efficacy.Results show that the hydrogels have porous structures.With an increase in LP content,the swelling rate grows in the early stage of immersion in buffer and drops later.The swelling ratio ranged from 986%to 1677%,and stiffness varied from 777 Pa to 1792 Pa.The addition of LP reduced the mechanical strength and delayed gelation and degradation of the hydrogels.However,the most important discovery was that gp increases the viability of NIH 3T3 cells from 94%to 137%,and LP raises the bacteriostatic efficacy from 51%to 78%.Hydrogels synthesized from 1%genipin,3%chitosan,and 4%licorice polysaccharide showed the best antibacterial and fibroblast proliferation promoting activities.They exhibited moderate swelling and degradation rates over time,while being more suitable to affect healing of chronic wound infections.These results provide a new strategy to improve the antibacterial effectiveness and cyto-compatibility of chitosan hydrogels with water soluble active LPs from Glycyrrhiza that derive from traditional Chinese medicine.
基金supported by the National Science Foundation of China(81301345)
文摘The variety of wound types has resulted in a wide range of wound dressings, with new products frequently being introduced to target different aspects of the wound healing process. The ideal wound dressing should achieve rapid healing at a reasonable cost, with minimal inconvenience to the patient. Microcurrent dressing, a novel wound dressing with inherent electric activity, can generate low-level microcurrents at the device-wound contact surface in the presence of moisture and can provide an advanced wound healing solution for managing wounds. This article offers a review of the effects and mechanisms of the microcurrent dressing on the healing of skin wounds.
文摘Background: The value of periodontal dressing and its effects on periodontal wound healing have been questioned. Besides, the early healing of the gingival and periodontal wounds in oral cavity should be emphasized to promote the treatment outcome. Several studies pointed out a potential positive effect of silver nanoparticles (NPs) on the healing process of skin wounds. The present work aimed to design silver NPs periodontal dressing and then, evaluated its effects on gingival wound healing following operation. Methods: Thirty healthy adolescent female rabbits were used in this study. They had intact teeth and the clinical and radiographic examination revealed no periodontal disease. Silver NPs were added to carbonate methyl cellulose as base with two different concentrations of 25% v/v (Group A) and 50% v/v (Group B). On the basis of simple randomized allocation, gingivectomy was performed at the buccal gingiva of the left and right mandibular incisors and subsequently, untreated wounds in the control area were covered with periodontal pack and periodontal dressings A and B were applied in the test regions. Histological changes were monitored in day 4 and 7 post operation to evaluate the inflammatory and repair stage of healing process. Results: We observed significant difference in the inflammatory and repair parameters of the healing process between surgical sites treated with this periodontal dressing and control group. Besides, wounds treated with silver NPs dressing in general terms had all the hallmarks of relatively complete healing one week post operatively. Conclusion: The results indicated positive potential therapeutic effects for this new formulation of periodontal dressing on acceleration of surgical wound healing that led to improvement of periodontal treatment consequences following operation.
文摘A number of materials are utilized to develop wound care dressing materials with metallic treatments such as ionic silver and zinc. Metallic ions if used for a prolonged time may lead to toxicity. Alternatively chitin,a natural polysaccharide found in nature, is utilized. It is found in fungi, crabs, mushrooms,squids, octopus, and many other living organisms. Chitin has similar structure to cellulose but its deacetylated derivate chitosan has amine groups that provide potential antibacterial properties along with a number of other advantages. Chitin in its natural form is found in three different structural forms,namely α,β,and γ.The β-chitin and chitosan are mostly found in the exoskeleton of squids. Loligo and Humboldt squids were studied. It is anticipated that Humboldt chitin is more effective in serving as antibacterial material and can be utilized for wound care. Differences in steriochemical structure were observed among β-chitin structures obtained and amine group's presences were found along with ability of materials to swell.
文摘The main objective of this research work was the development of novel and responsive nonwoven composite structures containing gelling materials for wound management. The development of novel all inclusive collagen booster(CB) therapeutic nonwoven wound dressings was mainly focused on. It provides essential functional properties such as high absorption,vertical and lateral wicking,and antibacterial and acidic pH properties. The developed composite wound dressing consisted of carboxymethylcellulose(CMC) fibre and also it was reinforced with polylactic acid( PLA) fibre. The produced composite wound dressings were treated with two different CBs at 4% by using the spray method. The details of the CBs have not been disclosed in this paper due to the Intellectual Property Rights( IPR) issues. The important benefit of using CB treatment is that it allows the maintenance of an acidic pH environment at the wound area. It is well known that acidic pH reduces the wound healing time and enhances the wound healing process. Furthermore,one of the CBs not only promotes the proliferation of the epithelial cells in wounds but also can provide antibacterial action. The PLA fibre reinforced CMC composite dressing has enhanced wicking properties which help to minimise the pooling of exudate on the wound bed and as a result maceration is prevented. The CBs treated dressings maintain the wound bed in an acidic pH condition which also improves the wound healing process. In addition to the above-mentioned properties,the CB treatment imparts antimicrobial activity against Gram-positive and Gram-negative bacteria,thus resulting in the reduction in the propensity for wound infection. Ultimately,the research has proved that the 4% CB treatment enhances the antimicrobial activity and the acidic pH characteristics of the developed CMC /PLA composite wound dressings.
基金Science and Technology Committee of Shanghai Municipality,China(No.14441901600)Fundamental Research Funds for the Central Universities,China(No.16D110119)“111 Project”Biomedical Textile Materials Science and Technology,China(No.B07024)
文摘Collagen(Col)/chitosan(CS)nanofibrous membrane has great potential to be used as wound dressing.However,current Col/CS nanofibrous membrane produced from electrospinning can not offer sufficient mechanical strength for practical applications.Herein,a novel mixed solvent was used to prepare next-generation high-strength Col/CS nanofibrous membrane.Meanwhile,the optimal Col to CS weight ratio was investigated as well.The asproduced membrane was examined by scanning electron microscopy(SEM),attenuated total reflectance Fourier transform infrared spectroscopy(ATR-FTIR),differential scanning calorimetry(DSC),and XF-1A tester to study its morphological,chemical,thermal and mechanical properties.The preliminary results demonstrated that the mechanical properties of Col/CS nanofibrous membranes were enhanced substantially with the increase of CS weight ratios from 0 to 90%and the optimal Col to CS weight ratio was determined to be 1∶1.A promising way was presented to fabricate Col/CS electrospun nanofibrous membrane with sufficient mechanical strength for practical wound dressing applications.
基金Science and Technology Commission of Shanghai Municipality,China(No.16410723700)“111 Project”Biomedical Textile Materials Science and Technology,China(No.B07024)UK-China Joint Laboratory for Therapeutic Textiles Based at Donghua University
文摘To obtain the wound dressings which can accelerate healing effectively,vitamin E D-α-Tocopherol polyethylene glycol succinate(vitamin E TPGS),one of the common derivatives of the unstable vitamins E,was successfully incorporated into P(LLA-CL)nanofibers by electrospinning.Electron microscopy showed that the smooth cylindrical fibers were obtained,albeit with a small amount of beading visible for the vitamins-loaded fibers.The diameters of the P(LLA-CL)fibers decreased with the addition of vitamins.The incorporation of the vitamin E TPGS in the electrospun fibers was confirmed by Fourier transform infrared spectroscopy(FTIR).Moreover,X-ray diffraction(XRD)indicated that vitamin E TPGS existed in the amorphous physical form after electrospinning.Fibers containing vitamin E TPGS showed a sustained release profile over more than 100 h in vitro.Antibacterial tests demonstrated that fibers loaded with vitamin E TPGS were effective in inhibiting the growth of E.coli and S.aureus.MTT assay showed that the fibers could promote the proliferation of L929 fibroblasts.These results above demonstrate the potential of P(LLA-CL)/vitamins E TPGS(P/E)as advanced wound dressing materials.
文摘Objective:Research on the effect of moist wound healing theory in a combination with modern new dressing treatment in patients diagnosed with pressure ulcers.Method:Selected 30 patients with pressure ulcers from our hospital,which is Shandong Tai an Municipal Hospital,from January 2019 to January 2021 were divided into experimental group(15 cases,treated with moist wound healing theory combined with modern new dressings)and control group(15 cases,applied conventional treatments).The treatment effect,time of wound edema subsidence,wound healing time,number of dressing changes,granulation tissue growth time,and diameter reduction time were compared between the two groups.Results:The total effective rate of the experimental group(93.33%,14/15)was higher than that of the control group(53.33%,8/15),P<0.05;the time to subsidence of wound edema in the experimental group was(3.11±0.22),and the time for wound healing was(12.78±0.45),the number of dressing changes(7.13±0.34)times,the growth time of granulation tissue(5.43±2.22),the diameter reduction time(6.25±3.75),compared with the control group,P<0.05.Conclusion:In the clinical treatment of patients diagnosed with pressure ulcers,the effective combination of moist healing theory and modern new dressing therapy has significant effects,whereby it speeds up the healing process of the pressure ulcers,and it is proven to be worthy to be promoted for usage.
基金supported by the National Natural Science Foundation of China(61402486)。
文摘Background:The exogenous application of low-intensity electric stimulation(ES)may mimic a natural endogenous bioelectric current and accelerate the repair process of skin wounds.This study designed a novel microcurrent dressing(MCD)and evaluated its potential effects on wound healing in a rat skin defect model.Methods:First,wireless ES was integrated into a medical cotton cushion to fabricate the MCD,and its electrical property was examined by using a universal power meter.Then,animal experiments were conducted to evaluate the MCD’s effect.Forty-five rats were randomized into control(Con)group,Vaseline gauze(VG)group and MCD group.A full-thickness round skin incision 1.5 cm in diameter was made on the back of each animal.Apart from routine disinfection,the Con rats were untreated,whereas the other two groups were treated with VG or MCD.On days 3,7 and 14 post injury,the wound areas were observed and measured using image analysis software following photography,and the skin samples were harvested from wound tissue.Then,histopathological morphology was observed routinely by hematoxylin and eosin(HE)staining;tumor necrosis factorα(TNF-α)and interleukin(IL)-1βexpression were detected by Western blotting.Vascular endothelial growth factor(VEGF)and epidermal growth factor(EGF)expression were detected with immunohistochemistry.Results:The MCD generated a sf electric potential greater than 0.95 V.Animal experiments showed that the woundhealing rate in the MCD group was significantly increased compared with the Con and VG groups(P<0.05 or P<0.01).Histopathological observation revealed an alleviated inflammatory response,induced vascular proliferation and accelerated epithelization in the MCD group.Moreover,samples from the MCD group expressed reduced TNF-αand IL-1βlevels and increased VEGF and EGF levels compared with those of the other two groups(P<0.05 or P<0.01).However,no significant difference was noted between the Con and VG groups at each time point.Conclusions:The MCD generates a stable and lasting ES and significantly promotes wound healing by reducing inflammation duration and increasing growth factors expression.Thus,MCD may act as a promising biomaterial device for skin wound healing.
文摘Although the treatment of burn wounds has made great progress, the incidence of wound infection is still the main cause of high mortality. In this study, a silk fibroin (SF) scaffold wound dressing incorporated with Gentamicin Sulfate (GS) was developed for the treatment of burn infected wounds, in which GS was used as anti-bacterial agent. GS was mixed with silk fibroin solution and then processed into GS-SF composite scaffold via electro-spinning. The results showed the scaffold exhibited uniform polyporous morphology with 80% porosity. Induced by methanol, the scaffold presented much improved mechanical properties and stability to protease <em>XIV</em>. More important, the scaffold presented significant growth inhibition on both Gram-positive (<em>Staphylococcus aureus</em>) and Gram-negative (<em>Pseudomonas aeruginosa and Escherichia coli</em>) bacteria.
文摘There is currently no consensus regarding the management of acute cutaneous reactions emerging from a concurrent treatment of radio-and chemotherapy, the goal of this case study series is to provide scientific evidence based on clinical practice regarding the efficacy of a film-forming wound dressing for patients receiving combined cancer therapy, in particular examples where the reactions are expected to be intense. In all the described cases, management of acute skin reactions allowed the cancer therapy to be finalized, instead of being interrupted due to an increase in the severity of the reactions. It has been shown in the current literature that the lack of compliance with treatment plans correlates with poorer clinical outcome. Evidence from the cases presented suggest that the studied dressing is safe and efficacious in the treatment and the prevention of acute cutaneous reactions arising from combined cancer therapy.
基金This research is supported by Chongqing Research Program of Basic Research and Frontier Technology(No.cstc2019jcyj-msxmX0164 to Jiang)Science and Technology Research Program of Chongqing Municipal Education Commission(No.KJQN201900414 to Jiang)Special Project on Philosophy and Social Sciences of Chongqing Medical University(No.201704 to Xiong).
文摘A silk fibroin(SF)spongy wound dressing incorporated with silver nanoparticles(Ag-NPs)was developed for biomedical applications.Ag-NPs were efficiently synthesized in situ via ultra violet(UV)with AgNO_(3) as precursor and silk fibroin as reducing and protecting agent,respectively.After lyophilization,the formed silk fibroin spongy wound dressing(SFWD)exhibited polyporous morphology and inner lamellae structures,with uniform dispersion of Ag-NPs.The porous structure provided SFWD with the ability to absorb tissue exudatealmost 6 times of its own weight,which could guarantee the sustained release of Ag-NPs.By methanol treatment,SFWD showed much improved mechanical properties and more stable to protease XIV.The cyto-compatibility of SFWD was supported by normal adherence and proliferation of NIH3T3 fibroblasts in sponges extracting culture medium.More important,the SFWD showed significant growth inhibition in both plate culture assays and bacterial suspension assays,with Gram-positive(Staphylococcus aureus)and Gram-negative(Pseudomonas aeruginosa and Escherichia coli).In a cutaneous excisional mouse model,the average healing rates of SFWD was significantly higher than control and commercial bandages.The hematoxylin-eosin(HE)staining results of the wound section also showed that SFWD could recruit more cells and promote tissue formation on the wound edges.
基金Natural Science Foundation of Shanghai,China(No.14ZR1401000)Shanghai University Students Innovation Project of China(No.sh201410255026)National Natural Science Foundation of China(No.51303021)
文摘A porous,biocompatible,and modifiable chitosan (CS)/poly (vinyl alcohol) (PVA) hybrid membrane, which can be evaluated as wound dressing,has been prepared by lyophilization method and using the low toxicity solvents. Experiments illustrated that the moisture regain and porosity rate of polymer blend membranes had the similar variation tendency and got the maximum value at the case of CS/PVA weight ratio of 6∶4. And the value of water vapor transmission rate( WVTR) is conductive to the healing of wound and desirable for the application as a wound dressing.Mechanical performance test of blend membrane showed that the presence of PVA could effectively improve the interaction between CS molecules. The scanning electron microscopy( SEM)photograph confirmed the porous surface on top-layer supported by a macroporous sponge-like sub-layer of this novel type of CS blend membrane. Besides, Fourier transform infrared spectroscopy( FTIR) revealed the facts that the two polymers were physically bended and certain chemical actions took place,which illustrated the good compatibility between them. Differential scanning calorimetry(DSC) results showed that decomposition reaction occurred in CS at about 210℃. Introducing of PVA to CS made the decomposition temperature of blend membrane decrease. The good properties,such as moisture regain,porosity rate,and WVTR,of this kind of CS/PVA blend membranes suggested a potential application as a wound dressing in the future.
