Constructing a functional hybrid coating appears to be a promising strategy for addressing the poor corrosion resistance and insufficient endothelialization of Mg-based stents.Nevertheless,the steps for preparing comp...Constructing a functional hybrid coating appears to be a promising strategy for addressing the poor corrosion resistance and insufficient endothelialization of Mg-based stents.Nevertheless,the steps for preparing composite coatings are usually complicated and time-consuming.Herein,a novel composite coating,composed of bioactive magnesium thioctic acid(MTA)layer formed by deposition and corrosion-resistant magnesium hydroxide(Mg(OH)_(2))layer grown in situ,is simply fabricated on ZE21B alloys via one-step electrodeposition.Scanning electron microscopy(SEM)shows that the electrodeposited coating has a compact and uniform structure.And the high adhesion of the MTA/Mg(OH)_(2)hybrid coating is also confirmed by the micro-scratch test.Electrochemical test,scanning kelvin probe(SKP),and hydrogen evolution measurement indicate that the hybrid coating effectively reduces the degradation rate of Mg substrates.Haemocompatibility experiment and cell culture trial detect that the composite coating is of fine biocompatibility.Finally,the preparation mechanism of MTA/Mg(OH)_(2)hybrid coatings is discussed and proposed.This coating shows a great potential application for cardiovascular stents.展开更多
Developing high-performance aqueous Zn-ion batteries from sustainable biomass becomes increasingly vital for large-scale energy storage in the foreseeable future.Therefore,γ-MnO_(2)uniformly loaded on N-doped carbon ...Developing high-performance aqueous Zn-ion batteries from sustainable biomass becomes increasingly vital for large-scale energy storage in the foreseeable future.Therefore,γ-MnO_(2)uniformly loaded on N-doped carbon derived from grapefruit peel is successfully fabricated in this work,and particularly the composite cathode with carbon carrier quality percentage of 20 wt%delivers the specific capacity of 391.2 mAh g^(−1)at 0.1 A g^(−1),outstanding cyclic stability of 92.17%after 3000 cycles at 5 A g^(−1),and remarkable energy density of 553.12 Wh kg^(−1)together with superior coulombic efficiency of~100%.Additionally,the cathodic biosafety is further explored specifically through in vitro cell toxicity experiments,which verifies its tremendous potential in the application of clinical medicine.Besides,Zinc ion energy storage mechanism of the cathode is mainly discussed from the aspects of Jahn–Teller effect and Mn domains distribution combined with theoretical analysis and experimental data.Thus,a novel perspective of the conversion from biomass waste to biocompatible Mn-based cathode is successfully developed.展开更多
The repair and regeneration of bone defects are highly challenging orthopedic problems.Recently,Mg-based implants have gained popularity due to their unique biodegradation and elastic modulus similar to that of human ...The repair and regeneration of bone defects are highly challenging orthopedic problems.Recently,Mg-based implants have gained popularity due to their unique biodegradation and elastic modulus similar to that of human bone.The aim of our study is to develop a magnesium alloy with a controllable degradation that can closely match bone tissue to help injuries heal in vivo and avoid cytotoxicity caused by a sudden increase in ion concentration.In this study,we prepared and modified Mg-3Zn,Mg-3Zn-1Y,and Mg-2Zn-1Mn by hot extrusion,and used Mg-2.5Y-2.5Nd was as a control.We then investigated the effect of additions of Y and Mn on alloys'properties.Our results show that Mn and Y can improve not only compression strength but also corrosion resistance.The alloy Mg-2Zn-1Mn demonstrated good cytocompatibility in vitro,and for this reason we selected it for implantation in vivo.The degraded Mg-2Zn-1Mn implanted a bone defect area did not cause obvious rejection and inflammatory reaction,and the degradation products left no signs of damage to the heart,liver,kidney,or brain.Furthermore,we find that Mg-2Zn-1Mn can promote an osteoinductive response in vivo and the formation of bone regeneration.展开更多
AIM: To establish an untransfected human corneal epithelial (HCEP) cell line and characterize its biocompatibility with denuded amniotic membrane (dAM).METHODS: The torn HCEP pieces were primarily cultured in DMEM/F12...AIM: To establish an untransfected human corneal epithelial (HCEP) cell line and characterize its biocompatibility with denuded amniotic membrane (dAM).METHODS: The torn HCEP pieces were primarily cultured in DMEM/F12 media (pH 7.2) supplemented with 20% fetal bovine serum and other necessary factors,yielding an HCEP cell line which was its growth performance,chromosome morphology,tumorigenicity and expression of marker proteins analyzed.In addition,the biocompatibility of HCEP cells with dAM was evaluated through histological and immunocytochemistry analyses and with light,electron and slit-lamp microscopies.RESULTS: HCEP cells proliferated to confluence in 3 weeks,which have been subcultured to passage 160.A continuous untransfected HCEP cell line,designated as utHCEPC01,was established with a population doubling time of 45.42 hours as was determined at passage 100.The cells retained HCEP cell properties as were approved by chromosomal morphology and the expression of keratin 3.They,with no tumorigenicity,formed a multilayer epithelium-like structure on dAMs through proliferation and differentiation during air-liquid interface culture,maintained expression of marker proteins including keratin 3 and integrin β1 and attached tightly to dAMs.The reconstructed HCEP was highly transparent and morphologically and structurally similar to the original.CONCLUSION: An untransfected and non-tumorigenic HCEP cell line was established in this study.The cells maintained expression of marker proteins.The cell line was biocompatible with dAM.It holds the potential of being used for in vitro reconstruction of tissue-engineered HCEP,promising for the treatment of diseases caused by corneal epithelial disorders.展开更多
Mg-Ca alloys have recently attracted great attention towards the research in the field of orthopedic biodegradable implants.This study presents an in vitro degradation assessment of Mg-0.8Ca(0.8 wt.%of Ca)alloy in Han...Mg-Ca alloys have recently attracted great attention towards the research in the field of orthopedic biodegradable implants.This study presents an in vitro degradation assessment of Mg-0.8Ca(0.8 wt.%of Ca)alloy in Hank’s balanced salt solution(HBSS).Immersion,hydrogen evolution and electrochemical behavior was studied as well as the cytotoxicity of the degradation products.Morphology and phase composition of the corrosion products were studied using SEM,EDX and XRD techniques.Degradation in HBSS resulted in the formation of the needle-shaped carbonated hydroxyapatite which was similar to the biological apatite in the human bone.Degradation kinetics showed that Mg-0.8Ca alloy had approximately 3-fold faster degradation rate than the pure Mg(1.08±0.38 mm/year for Mg-0.8Ca and 0.35±0.17 mm/year for pure Mg),as observed in two independent experiments.Both,pure Mg and Mg-0.8Ca alloy were biocompatible,generating no cytotoxic degradation products against human-derived HEK 293 cells.Thus,the Mg-0.8Ca alloy was found to be a promising biodegradable implant in terms of bioactivity and compatibility with human cell lines.Depending on the application of the implant and the estimated healing time of the bone,the desired degradation rate of an implant can be controlled by the Mg-Ca composition of such alloys.展开更多
AIM:To establish an untransfected human corneal stromal(HCS) cell line and characterize its biocompatibility to acellular porcine corneal stroma(aPCS).· METHODS:Primary culture was initiated with a pure populatio...AIM:To establish an untransfected human corneal stromal(HCS) cell line and characterize its biocompatibility to acellular porcine corneal stroma(aPCS).· METHODS:Primary culture was initiated with a pure population of HCS cells in DMEM/F12 media(pH 7.2) containing 20% fetal bovine serum and various necessary growth factors.The established cell line was characterized by growth property,chromosome analysis,tumorigenicity assay,expression of marker proteins and functional proteins.Furthermore,the biocompatibility of HCS cells with aPCS was examined through histological and immunocytochemistry analyses and with light,electron microscopies.· RESULTS:HCS cells proliferated to confluence 2 weeks later in primary culture and have been subcultured to passage 140 so far.A continuous untransfected HCS cell line with a population doubling time of 41.44 hours at passage 80 has been determined.Results of chromosome analysis,morphology,combined with the results of expression of marker protein and functional proteins suggested that the cells retained HCS cell properties.Furthermore,HCS cells have no tumorigenicity,and with excellent biocompatibility to aPCS.· CONCLUSION:An untransfected and non-tumorigenic HCS cell line has been established,and the cells maintained positive expression of marker proteins and functional proteins.The cell line,with excellent biocompatibility to aPCS,might be used for in vitro reconstruction of tissue-engineered HCS.展开更多
AIM: To study the optical property and biocompatibility of a tissue engineering cornea.METHODS: The cross-linker of N-(3-Dimethylaminoropyl)-N'ethylcarbodiimide hydrochloride(EDC)/ N-Hydroxysuccin- imide (NHS) was...AIM: To study the optical property and biocompatibility of a tissue engineering cornea.METHODS: The cross-linker of N-(3-Dimethylaminoropyl)-N'ethylcarbodiimide hydrochloride(EDC)/ N-Hydroxysuccin- imide (NHS) was mixed with Type I collagen at 10% (weight/volume). The final solution was molded to the shape of a corneal contact lens. The collagen concentrations of 10%, 12.5%, 15%, 17.5% and 20% artificial corneas were tested by UV/vis-spectroscopy for their transparency compared with normal rat cornea. 10-0 sutures were knotted on the edges of substitute to measure the corneal buttons's mechanical properties. Normal rat corneal tissue primary culture on the collagen scaffold was observed in 4 weeks. Histopathologic examinations were performed after 4 weeks of in vitro culturing.RESULTS: The collagen scaffold appearance was similar to that of soft contact lens. With the increase of collagen concentration, the transparency of artificial corneal buttons was diminished, but the toughness of the scaffold was enhanced. The scaffold transparency in the 10% concentration collagen group resembled normal rat cornea. To knot and embed the scaffold under the microscope, 20% concentration collagen group was more effective during implantation than lower concentrations of collagen group. In the first 3 weeks, corneal cell proliferation was highly active. The shapes of cells that grew on the substitute had no significant difference when compared with the cells before they were moved to the scaffold. However, on the fortieth day, most cells detached from the scaffold and died. Histopathologic examination of the primary culture scaffold revealed well grown corneal cells tightly attached to the scaffold in the former culturing. CONCLUSION: Collagen scaffold can be molded to the shape of soft contact corneal lens with NHS/EDC. The biological stability and biocompatibility of collagen from animal species may be used as material in preparing to engineer artificial corneal scaffold.展开更多
Recently,tissue engineering (TE)is one of the fast growing research fields due the accessibility of extra-molecular matrix (ECM)at cellular and molecular level with valuable potential prospective of hydrogels.The enha...Recently,tissue engineering (TE)is one of the fast growing research fields due the accessibility of extra-molecular matrix (ECM)at cellular and molecular level with valuable potential prospective of hydrogels.The enhancement in the production of hydrogel-based cellular scaffolds with the structural composition of ECM has been accelerated with involvement of rapid prototyping techniques.Basically,the recreation of ECM has been derived from naturally existed or synthetic hydrogelbased polymers.The rapid utilization of hydrogels in TE puts forward the scope of bioprinfing for the fabrication of the functional biological tissues,cartilage,skin and artificial organs.The main focus of the researchers is on biofabrication of the biomaterials with maintaining the biocompatibility,biodegradability and increasing growth efficiency.In this review, biological development in the structure and cross-linking connections of natural or synthetic hydrogels are discussed.The methods and design criteria that influence the chemical and mechanical properties and interaction of seeding cells before and after the implantations are also demonstrated.The methodology of bioprinting techniques along with recent development has also been reviewed.In the end,some capabilities and shortcomings are pointed out for further development of hydrogels-based scaffolds and selection of bioprinting technology depending on their application.展开更多
Biodegradable magnesium alloy stents(MAS)have great potential in the treatment of cardiovascular diseases.However,too fast degradation and the poor biocompatibility are still two key problems for the clinical utility ...Biodegradable magnesium alloy stents(MAS)have great potential in the treatment of cardiovascular diseases.However,too fast degradation and the poor biocompatibility are still two key problems for the clinical utility of MAS.In the present work,a functional coating composed of hydrophilic polymers and bioactive peptides was constructed on magnesium alloy to improve its corrosion resistance and biocompatibility in vitro and in vivo.Mg-Zn-Y-Nd(ZE21B)alloy modified with the functional coating exhibited moderate surface hydrophilicity and enhanced corrosion resistance.The favourable hemocompatibility of ZE21B alloy with the functional coating was confirmed by the in vitro blood experiments.Moreover,the modified ZE21B alloy could selectively promote the adhesion,proliferation,and migration of endothelial cells(ECs),but suppress these behaviors of smooth muscle cells(SMCs).Furthermore,the modified ZE21B alloy wires could alleviate intimal hyperplasia,enhance corrosion resistance and re-endothelialization in vivo transplantation experiment.These results collectively demonstrated that the functional coating improved the corrosion resistance and biocompatibility of ZE21B alloy.This functional coating provides new insight into the design and development of novel biodegradable stents for biomedical engineering.展开更多
Silicon nitride (Si3N4) ceramic is an attractive material for dental applications, especially used as a dental core material, due to its unique properties including high fracture toughness, high strength, high wear re...Silicon nitride (Si3N4) ceramic is an attractive material for dental applications, especially used as a dental core material, due to its unique properties including high fracture toughness, high strength, high wear resistance and non-cytotoxicity. In this study, the Si3N4 ceramic was fabricated by a non-pressure sintering technique at a relatively low sintering temperature of 1650℃ in nitrogen atmosphere. Borosilicate glass and 5 wt% ZrO2-added borosilicate glass were used for coating on the Si3N4 core surface because of their compatibility in thermal expansion, high chemical resistance and bio-inert. The specimens were then fired in electric tube furnace at 1100℃. The Vickers microhardness of borosilicate glass and 5 wt% ZrO2-added borosilicate glass veneering materials were measured and compared with the commercial dental veneer porcelain as a control (VITA VMK 95). The cytotoxicity of the Si3N4 ceramic and the veneering materials were tested by MTT assay, using human gingival fibroblasts (HGF) and periodontal ligament fibroblasts (HPDLF). The results indicate that the Si3N4 ceramic and Si3N4 ceramic veneered with borosilicate glass or 5 wt% ZrO2-added borosilicate glass veneering materials tested in this study are not toxic to oral tissue and can be used to produce dental prostheses.展开更多
DNA synthesis and collagen formations on the implant material by cell culture in vitro are the most important phenotypical expression to estimate the biocompatibility. In this part, DNA synthesis and collagen formatio...DNA synthesis and collagen formations on the implant material by cell culture in vitro are the most important phenotypical expression to estimate the biocompatibility. In this part, DNA synthesis and collagen formation on implant materials were quantitatively and qualitatively estimated by radioactive isotope H + thymidine to incorporate into DNA chains, H + proline to incorporate into type I collagen proteins followed by scin tillation counting and antibody antigen immunocytochemistry staining, respectively. Research results demonstrate that hydroxyapatite (HA) stimulates DNA synthesis and collagen formation on the material whereas this stimulation is restricted by adding spinel to the materials. There are statistical differences between the influences of material components on both DNA synthesis and collagen formation. It is supposed that porous materials can supply more platforms for cell anchoring, and more DNA and collagen are synthesised on the porous materials. Immersion in culture medium results in new HA crystal formation on the porous HA materials.展开更多
Epoxy resin/polytetrafluorethylene coating TiNi arch wires have been fabricated by dipping method.The vickers hardness,adhesion force,the maximum static friction force and biocompatibility also have been examined.The ...Epoxy resin/polytetrafluorethylene coating TiNi arch wires have been fabricated by dipping method.The vickers hardness,adhesion force,the maximum static friction force and biocompatibility also have been examined.The results show that the vickers hardness,adhesion force and the maximum static friction force increase with the increase of the content of epoxy resin.And the epoxy resin/polytetrafluorethylene coatings are nontoxic.展开更多
BACKGROUND: Collagen-heparin sulfate scaffolds have been widely used to repair nerve injury and promote nerve regeneration. Previous research has evaluated scaffold biocompatibility by measuring gliocyte proliferation...BACKGROUND: Collagen-heparin sulfate scaffolds have been widely used to repair nerve injury and promote nerve regeneration. Previous research has evaluated scaffold biocompatibility by measuring gliocyte proliferation but not neuronal apoptosis. OBJECTIVE: To explore the biocompatibility of collagen-heparin sulfate scaffold in porcine brain by detecting peripheral neural apoptosis and protein expression. DESIGN, TIME AND SETTING: A randomized, controlled animal experiment was performed at the Laboratory of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, between March and June, 2008. MATERIALS: Rabbit anti-human Bax, Caspase-3 polyclonal antibody, rat anti-human Bcl-2 polyclonal antibody, streptavidin biotin-peroxidase complex (SABC) immunohistochemical kit, and TUNEL kit (Roche, USA) were used in this study. METHODS: Twenty adult piglets were randomly evenly divided into implantation and control groups. A collagen-heparin sulfate scaffold was implanted from the anterior fontanelle into the brain in the implantation group. The same puncture but no scaffold implantation was made in the control group. MAIN OUTCOME MEASURES: Cell apoptosis was detected using TUNEL; Bax, Bcl-2, and Caspase-3 expressions were measured using the SABC method. RESULTS: At days 1, 3, 7, and 14 after scaffold implantation, a few apoptotic cells were observed in the brain tissues near the puncture site, with more apoptotic cells in the implantation group (P < 0.05). However, both groups showed similar apoptosis levels by day 30 after implantation. Implan-tation increased Bax, Bcl-2, and Caspase-3 expressions on days 3 and 7 after implantation (P < 0.05) but decreased the ratio of Bcl-2 to Bax in the implantation group was significantly lower on days 3 and 7 (P < 0.05), with no significant difference by day 30 after implantation (P > 0.05). CONCLUSION: The collagen-heparin sulfate scaffold has good biocompatibility to porcine brain tissues.展开更多
In a previous study, we used natural butterfly wings as a cell growth matrix for tissue engineering materials and found that the surface of different butterfly wings had different ultramicrostructures, which can affec...In a previous study, we used natural butterfly wings as a cell growth matrix for tissue engineering materials and found that the surface of different butterfly wings had different ultramicrostructures, which can affect the qualitative growth of cells and regulate cell growth, metabolism, and gene expression. However, the biocompatibility and biosafety of butterfly wings must be studied. In this study, we found that Sprague-Dawley rat dorsal root ganglion neurons could grow along the structural stripes of butterfly wings, and Schwann cells could normally attach to and proliferate on different species of butterfly wings. The biocompatibility and biosafety of butterfly wings were further examined through subcutaneous implantation in Sprague-Dawley rats, intraperitoneal injection in Institute of Cancer Research mice, intradermal injection in rabbits, and external application to guinea pigs. Our results showed that butterfly wings did not induce toxicity, and all examined animals exhibited normal behaviors and no symptoms, such as erythema or edema. These findings suggested that butterfly wings possess excellent biocompatibility and biosafety and can be used as a type of tissue engineering material. This study was approved by the Experimental Animal Ethics Committee of Jiangsu Province of China(approval No. 20190303-18) on March 3, 2019.展开更多
The inflammation can be stimulated by the surgical implantation and biomaterial presence through the foreign body via bio-interface.Macrophages play a key role in the interaction of host tissue to implant surfaces.In ...The inflammation can be stimulated by the surgical implantation and biomaterial presence through the foreign body via bio-interface.Macrophages play a key role in the interaction of host tissue to implant surfaces.In present study,the immuno-inflammatory responses of genipin crosslinked gelatin matrices(GCGM)to macrophages in vitro and the host tissue surfaces in rats were investigated.The results showed that the mechanical properties,swelling and degradation of gelatin matrices were improved by the crosslinking of genipin at physiological conditions.The macrophage on the surface of GCGM could avoid to be activated.The interaction of macrophage and GCGM suggested that GCGM could reduce the inflammatory response with downregulating the production and m RNA expression of pro-inflammatory cytokines.The anti-inflammatory effect of GCGM was demonstrated to be related to inhibit nuclear factor kappa-B(NF-κB)signaling pathway.Furthermore,gelatin matrices crosslinked with genipin could decrease the acute and chronic inflammatory response interacting with host tissue surfaces to enhance the biocompatibility in rats.These results showed that GCGM could avoid to active macrophages and were endowed with anti-inflammatory properties,suggesting the significant potential for clinical success with the development of immunomodulatory biomaterials.展开更多
A novel PCL/HA/TiO_(2)hybrid coating on ZM21 Mg alloy substrate has been investigated for corrosion resistance, biocompatibility and mechanical integrity loss in terms of bending, compressive and tensile strength in p...A novel PCL/HA/TiO_(2)hybrid coating on ZM21 Mg alloy substrate has been investigated for corrosion resistance, biocompatibility and mechanical integrity loss in terms of bending, compressive and tensile strength in physiological media. The prepared hybrid coating was dip coated over ZM21 from HA/TiO_(2)and PCL solutions followed by creating a microporous PCL layer by utilizing Non-solvent Induced Phase Separation(NIPS) technique. The electrochemical measurement and in-vitro degradation study in SBF after 28 days showed that the PCL/HA/TiO_(2) hybrid coating reduced H2 evolution rate, weight loss, and corrosion rate by 64, 116 and 118 times respectively, as compared to uncoated ZM21 samples. The surface studies carried out using SEM-EDX, FTIR and XRD revealed formation of highly stable 3d flower-like HA crystals with Ca/P ratio of 1.60 in the PCL micropores. This dense apatite growth effectively protected the PCL/HA/TiO_(2)hybrid coated samples to maintain the good mechanical integrity even after 28 days of immersion as compared to HA/TiO_(2)composite coated, As-polished(A/P) and As-machined(A/M) samples. The failure analysis of samples under mechanical loading were performed using SEM-BSE-EBSD.The in-vitro cellular viability of L929 fibroblast cells on PCL/HA/TiO_(2)hybrid coating was found 50.47% higher with respect to control group,whereas bacterial viability was supressed by 57.15 and 62.35% against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacterial models. The comprehensive assessment indicates PCL/HA/TiO_(2)hybrid coating as a suitable candidate to delay early degradation and mechanical integrity loss of Mg-based alloys for devising biodegradable orthopaedic implant.展开更多
Cardiac valve replacement is an effective method to treat valvular heart disease.Artificial valves used routinely in clinic still have defects.In our study,we explored a novel method to modify the performance of Decel...Cardiac valve replacement is an effective method to treat valvular heart disease.Artificial valves used routinely in clinic still have defects.In our study,we explored a novel method to modify the performance of Decellularized Heart Valve(DHV)scaffold.The decellularized porcine aortic valve was prepared using sequential hydrophile and lipophile solubilization method.The sericin was extracted from silk fibroin-deficient silkworm cocoon by lithium bromide method.First,DHV was immersed in sericin solution to produce the sericin–DHV composite scaffold.Then,we modified the DHV by making a Polydopamine(PDA)coating on the DHV first and then binding the sericin.The physical properties and biological compatibility of our composite scaffold were assessed in vitro and in vivo.Sericin were successfully prepared,combined to DHV and improved its biocompatibility.PDA coating further promoted the combination of sericin on DHV and improved the physical properties of scaffolds.The decay rate of our modified valve scaffold was decreased in vivo and it showed good compatibility with blood.In conclusion,our modification improved the physical properties and biocompatibility of the valve scaffold.The combination of PDA and sericin promoted the recellularization of decellularized valves,showing great potential to be a novel artificial valve.展开更多
The introduction of biodegradable implant materials has significantly improved the postoperative subjective feelings of patients within the past few decades,among which magnesium alloy is widely considered a favorable...The introduction of biodegradable implant materials has significantly improved the postoperative subjective feelings of patients within the past few decades,among which magnesium alloy is widely considered a favorable choice as its appropriate biodegradability and evident antibacterial activity.Here,we reveal a semisolid rheo-formed Mg–Zn–Sr alloy ureteral implant that displayed suitable degradability and biocompatibility in a pig model.Refined non-dendritic microstructure was observed in the rheo-formed alloy,which led to ca.47%increase in ultimate tensile strength(from 195.0 MPa to 288.1 MPa)and more homogeneous degradation process compared with the untreated alloy.No post-interventional inflammation or pathological changes of the test animals were observed during the implantation period,and the corrosion rate(0.22±0.04 mm·y^(-1))perfectly fitted the clinical ureteral stent indwelling time.The urine bacteria numbers decreased from 88±13 CFU·mL^(-1)at 7 weeks post operation to 59±8 CFU·mL^(-1)at 14 weeks post operation,which confirmed the evident antibacterial activity of the alloy.Our study demonstrates that the Mg–Zn–Sr alloy is clinically safe for urinary system,enabling its efficacious use as ureteral implant materials.展开更多
Recently, there is a need of alternatives to antibiotics due to increasing antibiotic-resistant microorganism. Promising classes of bioactive polymers are 6-deoxy-6-amino cellulose derivatives. The purpose of the stud...Recently, there is a need of alternatives to antibiotics due to increasing antibiotic-resistant microorganism. Promising classes of bioactive polymers are 6-deoxy-6-amino cellulose derivatives. The purpose of the study was the assessment of the biocompatibility of 6-deoxy-6-aminoethyleneamino cellulose (AEAC) with different degree of substitution (DS). HaCaT keratinocyte cell viability was analyzed by measuring the cellular ATP content. The antibacterial activity against Staphylococcus aureus and Klebsiella pneumoniae was examined by microplate laser nephelometry. Thus, the ratio of half-maximal lethal concentration (LC50) and half-maximal inhibitory concentration (IC50) was calculated and described as biocompatibility index. The study revealed that biocompatibility of AEAC depends on the DS. AEAC of low DS (0.3) showed the best biocompatibility.展开更多
To evaluate the bioeompatibility of MIM 316L stainless steel, the percentage of S-period cells were detected by flow cytometry after L929 incubated with extraction of MIM 316L stainless steel, using titanium implant m...To evaluate the bioeompatibility of MIM 316L stainless steel, the percentage of S-period cells were detected by flow cytometry after L929 incubated with extraction of MIM 316L stainless steel, using titanium implant materials of clinical application as the contrast. Both materials were implanted in animal and the histopathological evaluations were carried out. The statistical analyses show that there are no significant differences between two groups (P＞0.05), which demonstrates that MIM 316L stainless steel has a good biocompatibility.展开更多
基金the National Key Research and Development Program of China(2018YFC1106703)the National Natural Science Foundation of China(No.U1804251)。
文摘Constructing a functional hybrid coating appears to be a promising strategy for addressing the poor corrosion resistance and insufficient endothelialization of Mg-based stents.Nevertheless,the steps for preparing composite coatings are usually complicated and time-consuming.Herein,a novel composite coating,composed of bioactive magnesium thioctic acid(MTA)layer formed by deposition and corrosion-resistant magnesium hydroxide(Mg(OH)_(2))layer grown in situ,is simply fabricated on ZE21B alloys via one-step electrodeposition.Scanning electron microscopy(SEM)shows that the electrodeposited coating has a compact and uniform structure.And the high adhesion of the MTA/Mg(OH)_(2)hybrid coating is also confirmed by the micro-scratch test.Electrochemical test,scanning kelvin probe(SKP),and hydrogen evolution measurement indicate that the hybrid coating effectively reduces the degradation rate of Mg substrates.Haemocompatibility experiment and cell culture trial detect that the composite coating is of fine biocompatibility.Finally,the preparation mechanism of MTA/Mg(OH)_(2)hybrid coatings is discussed and proposed.This coating shows a great potential application for cardiovascular stents.
基金supported by the National Natural Science Foundation of China[Grant no.51821004].
文摘Developing high-performance aqueous Zn-ion batteries from sustainable biomass becomes increasingly vital for large-scale energy storage in the foreseeable future.Therefore,γ-MnO_(2)uniformly loaded on N-doped carbon derived from grapefruit peel is successfully fabricated in this work,and particularly the composite cathode with carbon carrier quality percentage of 20 wt%delivers the specific capacity of 391.2 mAh g^(−1)at 0.1 A g^(−1),outstanding cyclic stability of 92.17%after 3000 cycles at 5 A g^(−1),and remarkable energy density of 553.12 Wh kg^(−1)together with superior coulombic efficiency of~100%.Additionally,the cathodic biosafety is further explored specifically through in vitro cell toxicity experiments,which verifies its tremendous potential in the application of clinical medicine.Besides,Zinc ion energy storage mechanism of the cathode is mainly discussed from the aspects of Jahn–Teller effect and Mn domains distribution combined with theoretical analysis and experimental data.Thus,a novel perspective of the conversion from biomass waste to biocompatible Mn-based cathode is successfully developed.
基金supported by the Hunan Provincial Science and Technology Department Project(2015WK3012)the National Natural Science Foundation of China(No.81571021)+3 种基金R&D of Key Project of Hunan Provincial Science and Technology Department(2022SK2010)R&D of Key Technology of Light Metal Air Battery,Transformation and Industrialization of Scientific and Technological Achievements of Hunan Province(2020GK2071)R&D of Key Technology and Materials of Magnesium Air Battery,Transformation of Scientific and Technological Achievements of Changsha City(Kh2005186)Technology Fundation(2021JCJQ-JJ-0432)。
文摘The repair and regeneration of bone defects are highly challenging orthopedic problems.Recently,Mg-based implants have gained popularity due to their unique biodegradation and elastic modulus similar to that of human bone.The aim of our study is to develop a magnesium alloy with a controllable degradation that can closely match bone tissue to help injuries heal in vivo and avoid cytotoxicity caused by a sudden increase in ion concentration.In this study,we prepared and modified Mg-3Zn,Mg-3Zn-1Y,and Mg-2Zn-1Mn by hot extrusion,and used Mg-2.5Y-2.5Nd was as a control.We then investigated the effect of additions of Y and Mn on alloys'properties.Our results show that Mn and Y can improve not only compression strength but also corrosion resistance.The alloy Mg-2Zn-1Mn demonstrated good cytocompatibility in vitro,and for this reason we selected it for implantation in vivo.The degraded Mg-2Zn-1Mn implanted a bone defect area did not cause obvious rejection and inflammatory reaction,and the degradation products left no signs of damage to the heart,liver,kidney,or brain.Furthermore,we find that Mg-2Zn-1Mn can promote an osteoinductive response in vivo and the formation of bone regeneration.
基金Supported by National High Technology Research and Development Program ("863" Program) of China(No. 2006AA02A132)
文摘AIM: To establish an untransfected human corneal epithelial (HCEP) cell line and characterize its biocompatibility with denuded amniotic membrane (dAM).METHODS: The torn HCEP pieces were primarily cultured in DMEM/F12 media (pH 7.2) supplemented with 20% fetal bovine serum and other necessary factors,yielding an HCEP cell line which was its growth performance,chromosome morphology,tumorigenicity and expression of marker proteins analyzed.In addition,the biocompatibility of HCEP cells with dAM was evaluated through histological and immunocytochemistry analyses and with light,electron and slit-lamp microscopies.RESULTS: HCEP cells proliferated to confluence in 3 weeks,which have been subcultured to passage 160.A continuous untransfected HCEP cell line,designated as utHCEPC01,was established with a population doubling time of 45.42 hours as was determined at passage 100.The cells retained HCEP cell properties as were approved by chromosomal morphology and the expression of keratin 3.They,with no tumorigenicity,formed a multilayer epithelium-like structure on dAMs through proliferation and differentiation during air-liquid interface culture,maintained expression of marker proteins including keratin 3 and integrin β1 and attached tightly to dAMs.The reconstructed HCEP was highly transparent and morphologically and structurally similar to the original.CONCLUSION: An untransfected and non-tumorigenic HCEP cell line was established in this study.The cells maintained expression of marker proteins.The cell line was biocompatible with dAM.It holds the potential of being used for in vitro reconstruction of tissue-engineered HCEP,promising for the treatment of diseases caused by corneal epithelial disorders.
基金The authors would like to thank the Helmholtz-Zentrum Geesthacht and Fesil Company(Germany)for the alloys syn-thesis and casting.
文摘Mg-Ca alloys have recently attracted great attention towards the research in the field of orthopedic biodegradable implants.This study presents an in vitro degradation assessment of Mg-0.8Ca(0.8 wt.%of Ca)alloy in Hank’s balanced salt solution(HBSS).Immersion,hydrogen evolution and electrochemical behavior was studied as well as the cytotoxicity of the degradation products.Morphology and phase composition of the corrosion products were studied using SEM,EDX and XRD techniques.Degradation in HBSS resulted in the formation of the needle-shaped carbonated hydroxyapatite which was similar to the biological apatite in the human bone.Degradation kinetics showed that Mg-0.8Ca alloy had approximately 3-fold faster degradation rate than the pure Mg(1.08±0.38 mm/year for Mg-0.8Ca and 0.35±0.17 mm/year for pure Mg),as observed in two independent experiments.Both,pure Mg and Mg-0.8Ca alloy were biocompatible,generating no cytotoxic degradation products against human-derived HEK 293 cells.Thus,the Mg-0.8Ca alloy was found to be a promising biodegradable implant in terms of bioactivity and compatibility with human cell lines.Depending on the application of the implant and the estimated healing time of the bone,the desired degradation rate of an implant can be controlled by the Mg-Ca composition of such alloys.
基金National High Technology Research and Development Program("863" Program) of China(No.2006AA02A132)
文摘AIM:To establish an untransfected human corneal stromal(HCS) cell line and characterize its biocompatibility to acellular porcine corneal stroma(aPCS).· METHODS:Primary culture was initiated with a pure population of HCS cells in DMEM/F12 media(pH 7.2) containing 20% fetal bovine serum and various necessary growth factors.The established cell line was characterized by growth property,chromosome analysis,tumorigenicity assay,expression of marker proteins and functional proteins.Furthermore,the biocompatibility of HCS cells with aPCS was examined through histological and immunocytochemistry analyses and with light,electron microscopies.· RESULTS:HCS cells proliferated to confluence 2 weeks later in primary culture and have been subcultured to passage 140 so far.A continuous untransfected HCS cell line with a population doubling time of 41.44 hours at passage 80 has been determined.Results of chromosome analysis,morphology,combined with the results of expression of marker protein and functional proteins suggested that the cells retained HCS cell properties.Furthermore,HCS cells have no tumorigenicity,and with excellent biocompatibility to aPCS.· CONCLUSION:An untransfected and non-tumorigenic HCS cell line has been established,and the cells maintained positive expression of marker proteins and functional proteins.The cell line,with excellent biocompatibility to aPCS,might be used for in vitro reconstruction of tissue-engineered HCS.
基金Scientific and Technological Research Projects of Educational Committee of Liaoning Province of China(No.2008S243)
文摘AIM: To study the optical property and biocompatibility of a tissue engineering cornea.METHODS: The cross-linker of N-(3-Dimethylaminoropyl)-N'ethylcarbodiimide hydrochloride(EDC)/ N-Hydroxysuccin- imide (NHS) was mixed with Type I collagen at 10% (weight/volume). The final solution was molded to the shape of a corneal contact lens. The collagen concentrations of 10%, 12.5%, 15%, 17.5% and 20% artificial corneas were tested by UV/vis-spectroscopy for their transparency compared with normal rat cornea. 10-0 sutures were knotted on the edges of substitute to measure the corneal buttons's mechanical properties. Normal rat corneal tissue primary culture on the collagen scaffold was observed in 4 weeks. Histopathologic examinations were performed after 4 weeks of in vitro culturing.RESULTS: The collagen scaffold appearance was similar to that of soft contact lens. With the increase of collagen concentration, the transparency of artificial corneal buttons was diminished, but the toughness of the scaffold was enhanced. The scaffold transparency in the 10% concentration collagen group resembled normal rat cornea. To knot and embed the scaffold under the microscope, 20% concentration collagen group was more effective during implantation than lower concentrations of collagen group. In the first 3 weeks, corneal cell proliferation was highly active. The shapes of cells that grew on the substitute had no significant difference when compared with the cells before they were moved to the scaffold. However, on the fortieth day, most cells detached from the scaffold and died. Histopathologic examination of the primary culture scaffold revealed well grown corneal cells tightly attached to the scaffold in the former culturing. CONCLUSION: Collagen scaffold can be molded to the shape of soft contact corneal lens with NHS/EDC. The biological stability and biocompatibility of collagen from animal species may be used as material in preparing to engineer artificial corneal scaffold.
文摘Recently,tissue engineering (TE)is one of the fast growing research fields due the accessibility of extra-molecular matrix (ECM)at cellular and molecular level with valuable potential prospective of hydrogels.The enhancement in the production of hydrogel-based cellular scaffolds with the structural composition of ECM has been accelerated with involvement of rapid prototyping techniques.Basically,the recreation of ECM has been derived from naturally existed or synthetic hydrogelbased polymers.The rapid utilization of hydrogels in TE puts forward the scope of bioprinfing for the fabrication of the functional biological tissues,cartilage,skin and artificial organs.The main focus of the researchers is on biofabrication of the biomaterials with maintaining the biocompatibility,biodegradability and increasing growth efficiency.In this review, biological development in the structure and cross-linking connections of natural or synthetic hydrogels are discussed.The methods and design criteria that influence the chemical and mechanical properties and interaction of seeding cells before and after the implantations are also demonstrated.The methodology of bioprinting techniques along with recent development has also been reviewed.In the end,some capabilities and shortcomings are pointed out for further development of hydrogels-based scaffolds and selection of bioprinting technology depending on their application.
基金project was the National Natural Science Foundation of China(Grant No.52101291)China Postdoctoral Science Foundation(Grant No.2020TQ0273)+1 种基金the National Key Research and Development Program of China(Grant No.2018YFC1106703)the Key Projects of the Joint Fund of the National Natural Science Foundation of China(Grant No.U1804251)。
文摘Biodegradable magnesium alloy stents(MAS)have great potential in the treatment of cardiovascular diseases.However,too fast degradation and the poor biocompatibility are still two key problems for the clinical utility of MAS.In the present work,a functional coating composed of hydrophilic polymers and bioactive peptides was constructed on magnesium alloy to improve its corrosion resistance and biocompatibility in vitro and in vivo.Mg-Zn-Y-Nd(ZE21B)alloy modified with the functional coating exhibited moderate surface hydrophilicity and enhanced corrosion resistance.The favourable hemocompatibility of ZE21B alloy with the functional coating was confirmed by the in vitro blood experiments.Moreover,the modified ZE21B alloy could selectively promote the adhesion,proliferation,and migration of endothelial cells(ECs),but suppress these behaviors of smooth muscle cells(SMCs).Furthermore,the modified ZE21B alloy wires could alleviate intimal hyperplasia,enhance corrosion resistance and re-endothelialization in vivo transplantation experiment.These results collectively demonstrated that the functional coating improved the corrosion resistance and biocompatibility of ZE21B alloy.This functional coating provides new insight into the design and development of novel biodegradable stents for biomedical engineering.
文摘Silicon nitride (Si3N4) ceramic is an attractive material for dental applications, especially used as a dental core material, due to its unique properties including high fracture toughness, high strength, high wear resistance and non-cytotoxicity. In this study, the Si3N4 ceramic was fabricated by a non-pressure sintering technique at a relatively low sintering temperature of 1650℃ in nitrogen atmosphere. Borosilicate glass and 5 wt% ZrO2-added borosilicate glass were used for coating on the Si3N4 core surface because of their compatibility in thermal expansion, high chemical resistance and bio-inert. The specimens were then fired in electric tube furnace at 1100℃. The Vickers microhardness of borosilicate glass and 5 wt% ZrO2-added borosilicate glass veneering materials were measured and compared with the commercial dental veneer porcelain as a control (VITA VMK 95). The cytotoxicity of the Si3N4 ceramic and the veneering materials were tested by MTT assay, using human gingival fibroblasts (HGF) and periodontal ligament fibroblasts (HPDLF). The results indicate that the Si3N4 ceramic and Si3N4 ceramic veneered with borosilicate glass or 5 wt% ZrO2-added borosilicate glass veneering materials tested in this study are not toxic to oral tissue and can be used to produce dental prostheses.
文摘DNA synthesis and collagen formations on the implant material by cell culture in vitro are the most important phenotypical expression to estimate the biocompatibility. In this part, DNA synthesis and collagen formation on implant materials were quantitatively and qualitatively estimated by radioactive isotope H + thymidine to incorporate into DNA chains, H + proline to incorporate into type I collagen proteins followed by scin tillation counting and antibody antigen immunocytochemistry staining, respectively. Research results demonstrate that hydroxyapatite (HA) stimulates DNA synthesis and collagen formation on the material whereas this stimulation is restricted by adding spinel to the materials. There are statistical differences between the influences of material components on both DNA synthesis and collagen formation. It is supposed that porous materials can supply more platforms for cell anchoring, and more DNA and collagen are synthesised on the porous materials. Immersion in culture medium results in new HA crystal formation on the porous HA materials.
文摘Epoxy resin/polytetrafluorethylene coating TiNi arch wires have been fabricated by dipping method.The vickers hardness,adhesion force,the maximum static friction force and biocompatibility also have been examined.The results show that the vickers hardness,adhesion force and the maximum static friction force increase with the increase of the content of epoxy resin.And the epoxy resin/polytetrafluorethylene coatings are nontoxic.
基金the National Natural Science Foundation of China, No. 30570628, 30770751
文摘BACKGROUND: Collagen-heparin sulfate scaffolds have been widely used to repair nerve injury and promote nerve regeneration. Previous research has evaluated scaffold biocompatibility by measuring gliocyte proliferation but not neuronal apoptosis. OBJECTIVE: To explore the biocompatibility of collagen-heparin sulfate scaffold in porcine brain by detecting peripheral neural apoptosis and protein expression. DESIGN, TIME AND SETTING: A randomized, controlled animal experiment was performed at the Laboratory of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, between March and June, 2008. MATERIALS: Rabbit anti-human Bax, Caspase-3 polyclonal antibody, rat anti-human Bcl-2 polyclonal antibody, streptavidin biotin-peroxidase complex (SABC) immunohistochemical kit, and TUNEL kit (Roche, USA) were used in this study. METHODS: Twenty adult piglets were randomly evenly divided into implantation and control groups. A collagen-heparin sulfate scaffold was implanted from the anterior fontanelle into the brain in the implantation group. The same puncture but no scaffold implantation was made in the control group. MAIN OUTCOME MEASURES: Cell apoptosis was detected using TUNEL; Bax, Bcl-2, and Caspase-3 expressions were measured using the SABC method. RESULTS: At days 1, 3, 7, and 14 after scaffold implantation, a few apoptotic cells were observed in the brain tissues near the puncture site, with more apoptotic cells in the implantation group (P < 0.05). However, both groups showed similar apoptosis levels by day 30 after implantation. Implan-tation increased Bax, Bcl-2, and Caspase-3 expressions on days 3 and 7 after implantation (P < 0.05) but decreased the ratio of Bcl-2 to Bax in the implantation group was significantly lower on days 3 and 7 (P < 0.05), with no significant difference by day 30 after implantation (P > 0.05). CONCLUSION: The collagen-heparin sulfate scaffold has good biocompatibility to porcine brain tissues.
基金supported by the National Natural Science Foundation of China,No. 31971276the Natural Science Foundation of Jiangsu Higher Education Institutions of China (Major Program),No. 19KJA320005 (both to JHH)。
文摘In a previous study, we used natural butterfly wings as a cell growth matrix for tissue engineering materials and found that the surface of different butterfly wings had different ultramicrostructures, which can affect the qualitative growth of cells and regulate cell growth, metabolism, and gene expression. However, the biocompatibility and biosafety of butterfly wings must be studied. In this study, we found that Sprague-Dawley rat dorsal root ganglion neurons could grow along the structural stripes of butterfly wings, and Schwann cells could normally attach to and proliferate on different species of butterfly wings. The biocompatibility and biosafety of butterfly wings were further examined through subcutaneous implantation in Sprague-Dawley rats, intraperitoneal injection in Institute of Cancer Research mice, intradermal injection in rabbits, and external application to guinea pigs. Our results showed that butterfly wings did not induce toxicity, and all examined animals exhibited normal behaviors and no symptoms, such as erythema or edema. These findings suggested that butterfly wings possess excellent biocompatibility and biosafety and can be used as a type of tissue engineering material. This study was approved by the Experimental Animal Ethics Committee of Jiangsu Province of China(approval No. 20190303-18) on March 3, 2019.
基金supported by the National Natural Science Foundation of China(81741119)Fundamental Research Funds for the Central Universities,China(3332020059)。
文摘The inflammation can be stimulated by the surgical implantation and biomaterial presence through the foreign body via bio-interface.Macrophages play a key role in the interaction of host tissue to implant surfaces.In present study,the immuno-inflammatory responses of genipin crosslinked gelatin matrices(GCGM)to macrophages in vitro and the host tissue surfaces in rats were investigated.The results showed that the mechanical properties,swelling and degradation of gelatin matrices were improved by the crosslinking of genipin at physiological conditions.The macrophage on the surface of GCGM could avoid to be activated.The interaction of macrophage and GCGM suggested that GCGM could reduce the inflammatory response with downregulating the production and m RNA expression of pro-inflammatory cytokines.The anti-inflammatory effect of GCGM was demonstrated to be related to inhibit nuclear factor kappa-B(NF-κB)signaling pathway.Furthermore,gelatin matrices crosslinked with genipin could decrease the acute and chronic inflammatory response interacting with host tissue surfaces to enhance the biocompatibility in rats.These results showed that GCGM could avoid to active macrophages and were endowed with anti-inflammatory properties,suggesting the significant potential for clinical success with the development of immunomodulatory biomaterials.
基金CSIR-IMTECH laboratory for providing the technical support in biocompatibility testing。
文摘A novel PCL/HA/TiO_(2)hybrid coating on ZM21 Mg alloy substrate has been investigated for corrosion resistance, biocompatibility and mechanical integrity loss in terms of bending, compressive and tensile strength in physiological media. The prepared hybrid coating was dip coated over ZM21 from HA/TiO_(2)and PCL solutions followed by creating a microporous PCL layer by utilizing Non-solvent Induced Phase Separation(NIPS) technique. The electrochemical measurement and in-vitro degradation study in SBF after 28 days showed that the PCL/HA/TiO_(2) hybrid coating reduced H2 evolution rate, weight loss, and corrosion rate by 64, 116 and 118 times respectively, as compared to uncoated ZM21 samples. The surface studies carried out using SEM-EDX, FTIR and XRD revealed formation of highly stable 3d flower-like HA crystals with Ca/P ratio of 1.60 in the PCL micropores. This dense apatite growth effectively protected the PCL/HA/TiO_(2)hybrid coated samples to maintain the good mechanical integrity even after 28 days of immersion as compared to HA/TiO_(2)composite coated, As-polished(A/P) and As-machined(A/M) samples. The failure analysis of samples under mechanical loading were performed using SEM-BSE-EBSD.The in-vitro cellular viability of L929 fibroblast cells on PCL/HA/TiO_(2)hybrid coating was found 50.47% higher with respect to control group,whereas bacterial viability was supressed by 57.15 and 62.35% against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacterial models. The comprehensive assessment indicates PCL/HA/TiO_(2)hybrid coating as a suitable candidate to delay early degradation and mechanical integrity loss of Mg-based alloys for devising biodegradable orthopaedic implant.
基金supported by the National Key Research and Development Program of China Stem Cell and Translational Research(2016YFA0101103)the National Natural Science Foundation of China(grant numbers 81930052,81901904,82000367,82001701).
文摘Cardiac valve replacement is an effective method to treat valvular heart disease.Artificial valves used routinely in clinic still have defects.In our study,we explored a novel method to modify the performance of Decellularized Heart Valve(DHV)scaffold.The decellularized porcine aortic valve was prepared using sequential hydrophile and lipophile solubilization method.The sericin was extracted from silk fibroin-deficient silkworm cocoon by lithium bromide method.First,DHV was immersed in sericin solution to produce the sericin–DHV composite scaffold.Then,we modified the DHV by making a Polydopamine(PDA)coating on the DHV first and then binding the sericin.The physical properties and biological compatibility of our composite scaffold were assessed in vitro and in vivo.Sericin were successfully prepared,combined to DHV and improved its biocompatibility.PDA coating further promoted the combination of sericin on DHV and improved the physical properties of scaffolds.The decay rate of our modified valve scaffold was decreased in vivo and it showed good compatibility with blood.In conclusion,our modification improved the physical properties and biocompatibility of the valve scaffold.The combination of PDA and sericin promoted the recellularization of decellularized valves,showing great potential to be a novel artificial valve.
基金National Natural Science Foundation of China(grant numbers 51771045 and U1764254)the Fundamental Research Funds for the Central Universities(grant number N2002016)for the financial supports。
文摘The introduction of biodegradable implant materials has significantly improved the postoperative subjective feelings of patients within the past few decades,among which magnesium alloy is widely considered a favorable choice as its appropriate biodegradability and evident antibacterial activity.Here,we reveal a semisolid rheo-formed Mg–Zn–Sr alloy ureteral implant that displayed suitable degradability and biocompatibility in a pig model.Refined non-dendritic microstructure was observed in the rheo-formed alloy,which led to ca.47%increase in ultimate tensile strength(from 195.0 MPa to 288.1 MPa)and more homogeneous degradation process compared with the untreated alloy.No post-interventional inflammation or pathological changes of the test animals were observed during the implantation period,and the corrosion rate(0.22±0.04 mm·y^(-1))perfectly fitted the clinical ureteral stent indwelling time.The urine bacteria numbers decreased from 88±13 CFU·mL^(-1)at 7 weeks post operation to 59±8 CFU·mL^(-1)at 14 weeks post operation,which confirmed the evident antibacterial activity of the alloy.Our study demonstrates that the Mg–Zn–Sr alloy is clinically safe for urinary system,enabling its efficacious use as ureteral implant materials.
文摘Recently, there is a need of alternatives to antibiotics due to increasing antibiotic-resistant microorganism. Promising classes of bioactive polymers are 6-deoxy-6-amino cellulose derivatives. The purpose of the study was the assessment of the biocompatibility of 6-deoxy-6-aminoethyleneamino cellulose (AEAC) with different degree of substitution (DS). HaCaT keratinocyte cell viability was analyzed by measuring the cellular ATP content. The antibacterial activity against Staphylococcus aureus and Klebsiella pneumoniae was examined by microplate laser nephelometry. Thus, the ratio of half-maximal lethal concentration (LC50) and half-maximal inhibitory concentration (IC50) was calculated and described as biocompatibility index. The study revealed that biocompatibility of AEAC depends on the DS. AEAC of low DS (0.3) showed the best biocompatibility.
文摘To evaluate the bioeompatibility of MIM 316L stainless steel, the percentage of S-period cells were detected by flow cytometry after L929 incubated with extraction of MIM 316L stainless steel, using titanium implant materials of clinical application as the contrast. Both materials were implanted in animal and the histopathological evaluations were carried out. The statistical analyses show that there are no significant differences between two groups (P＞0.05), which demonstrates that MIM 316L stainless steel has a good biocompatibility.
