BACKGROUND The recovery time of hand wounds is long,which can easily result in chronic and refractory wounds,making the wounds unable to be properly repaired.The treatment cycle is long,the cost is high,and it is pron...BACKGROUND The recovery time of hand wounds is long,which can easily result in chronic and refractory wounds,making the wounds unable to be properly repaired.The treatment cycle is long,the cost is high,and it is prone to recurrence and disability.Double layer artificial dermis combined with autologous skin transplantation has been used to repair hypertrophic scars,deep burn wounds,exposed bone and tendon wounds,and post tumor wounds.AIM To investigate the therapeutic efficacy of autologous skin graft transplantation in conjunction with double-layer artificial dermis in treating finger skin wounds that are chronically refractory and soft tissue defects that expose bone and tendon.METHODS Sixty-eight chronic refractory patients with finger skin and soft tissue defects accompanied by bone and tendon exposure who were admitted from July 2021 to June 2022 were included in this study.The observation group was treated with double layer artificial dermis combined with autologous skin graft transplantation(n=49),while the control group was treated with pedicle skin flap transplantation(n=17).The treatment status of the two groups of patients was compared,including the time between surgeries and hospital stay.The survival rate of skin grafts/flaps and postoperative wound infections were evaluated using the Vancouver Scar Scale(VSS)for scar scoring at 6 mo after surgery,as well as the sensory injury grading method and two-point resolution test to assess the recovery of skin sensation at 6 mo.The satisfaction of the two groups of patients was also compared.RESULTS Wound healing time in the observation group was significantly longer than that in the control group(P<0.05,27.92±3.25 d vs 19.68±6.91 d);there was no significant difference in the survival rate of skin grafts/flaps between the two patient groups(P>0.05,95.1±5.0 vs 96.3±5.6).The interval between two surgeries(20.0±4.3 d)and hospital stay(21.0±10.1 d)in the observation group were both significantly shorter than those in the control group(27.5±9.3 d)and(28.4±17.7 d),respectively(P<0.05).In comparison to postoperative infection(23.5%)and subcutaneous hematoma(11.8%)in the control group,these were considerably lower at(10.2%)and(6.1%)in the observation group.When comparing the two patient groups at six months post-surgery,the excellent and good rate of sensory recovery(91.8%)was significantly higher in the observation group than in the control group(76.5%)(P<0.05).There was also no statistically significant difference in two point resolution(P>0.05).The VSS score in the observation group(2.91±1.36)was significantly lower than that in the control group(5.96±1.51),and group satisfaction was significantly higher(P<0.05,90.1±6.3 vs 76.3±5.2).CONCLUSION The combination of artificial dermis and autologous skin grafting for the treatment of hand tendon exposure wounds has a satisfactory therapeutic effect.It is a safe,effective,and easy to operate treatment method,which is worthy of clinical promotion.展开更多
Objective: To investigate the application of artificial tiger bone powder on fracture healing time, wrist functional recovery and quality of life (QOL) in elderly patients with distal radius fracture. Methods: The stu...Objective: To investigate the application of artificial tiger bone powder on fracture healing time, wrist functional recovery and quality of life (QOL) in elderly patients with distal radius fracture. Methods: The study was a randomised controlled trials performed from January 2015 to December 2016 in a hospital. Elderly patients with distal radius fracture were divided into the treatment and the control groups by the random sealed envelope method. All patients were given splint or plaster fixation after manipulative reduction, and functional exercise, the treatment group was also given artificial tiger bone powder orally (trade name: Jintiange capsule), the control group was given an oral placebo in their appearance and usage identical with the treatment group. Prior to treatment and 6, 12 months after treatment, the wrist function was assessed by range of motion, including flexion-extension, radial-ulnar and pronation-supination, and the QOL was assessed by the Mos 36-item Short Form Health Survey. Each patient's fracture healing time was recorded. Results: Before treatment, there were no significant differences in wrist function and QOL between the two groups. At 6 and 12 months after treatment, the wrist function and QOL in the treatment group were better than those in the control group, the differences were statistically significant (P < 0.05). The fracture healing time in the treatment group was shorter than that of the control group, and the difference was statistically significant (P < 0.05). Conclusion: The early usage of artificial tiger bone powder for elderly patients with distal radius fracture can promote the healing of fracture, recovery of wrist joint function, and ultimately improve the QOL for elderly patients.展开更多
In the present work, we report the first bionanocomposite material formed by otoliths/ collagen/ bacterial cellulose (BC) networks (OCBC). This biomaterial is an osteoinductor or be, stimulates the bone regeneration, ...In the present work, we report the first bionanocomposite material formed by otoliths/ collagen/ bacterial cellulose (BC) networks (OCBC). This biomaterial is an osteoinductor or be, stimulates the bone regeneration, enabling bigger migration of the cells for formation of the bone tissue regeneration mainly because nanotolith are rich in minerals considered essential to the bone mineralization process on a protein matrix (otolin). The objective in this study was to analyze the regeneration capacity of bone defects treated with this bionanocomposite. Histological experiments shows bone tissue formation with high regularity, higher osteoblast activity and osteo-reabsorption activities areas. The results suggest the potential for this new biomaterial as a scaffold for bone tissue regeneration.展开更多
The aim of this study was to evaluate the outcome of autotransplantation or replantation of extracted teeth combining with reconstruction of alveolar bone defects in use of artificial bone grafting clinically and radi...The aim of this study was to evaluate the outcome of autotransplantation or replantation of extracted teeth combining with reconstruction of alveolar bone defects in use of artificial bone grafting clinically and radiographically. This article presents a more useful and convenient method for repairing tooth and reconstruction of bone defecting with some interesting cases. Eleven patients (seven men and four women) in whom teeth with complete root formation were extracted and autotransplanted, the bone of receiving area was Insufficient. All transplanted teeth were stabilized with orthodontic wire and resin or 4-0 silk sutures;at the same time, artificial bone powder was filled. In 11 cases, the missing teeth were restored by autogenous teeth and the alveolar bone defect was restored by artificial bone, the improvement in the radiographic and clinical parameters strongly suggest that it may be a useful therapy to solve the problem of the missing teeth and alveolar bone insufficiency simultaneously. However, the risk of replacement root resorption remains.展开更多
Recently,researchers have concentrated on studying ionic polymer metal composite(IPMC)artificial muscle,which has numerous advantages including a relatively large strain under low input voltage,flexibility,high respon...Recently,researchers have concentrated on studying ionic polymer metal composite(IPMC)artificial muscle,which has numerous advantages including a relatively large strain under low input voltage,flexibility,high response,low noise,light weight,and high driving energy density.This paper reports recent developments in IPMC artificial muscle,including improvement methods,modeling,and applications.Different types of IPMCs are described,along with various methods for overcoming some shortcomings,including improvement of Nafion matrix membranes,surface preparation of Nafion membranes,the choice of high-performing electrodes,and new electro-active polymers for enhancing the properties of IPMCs.IPMC models are also reviewed,providing theoretical guidance for studying the performance and applications of IPMCs.Successful applications such as bio-inspired robots,opto-mechatronic systems,and medical engineering are discussed.展开更多
All-solid-state lithium batteries(ASSLBs) employing sulfide electrolyte and lithium(Li) anode have received increasing attention due to the intrinsic safety and high energy density.However,the thick electrolyte layer ...All-solid-state lithium batteries(ASSLBs) employing sulfide electrolyte and lithium(Li) anode have received increasing attention due to the intrinsic safety and high energy density.However,the thick electrolyte layer and lithium dendrites formed at the electrolyte/Li anode interface hinder the realization of high-performance ASSLBs.Herein,a novel membrane consisting of Li_(6)PS_(5) Cl(LPSCl),poly(ethylene oxide)(PEO) and Li-salt(LiTFSI) was prepared as sulfide-based composite solid electrolyte(LPSCl-PEO3-LiTFSI)(LPSCl:PEO=97:3 wt/wt;EO:Li=8:1 mol/mol),which delivers high ionic conductivity(1.1 × 10^(-3) S cm^(-1)) and wide electrochemical window(4.9 V vs.Li^(+)/Li) at 25 ℃.In addition,an ex-situ artificial solid electrolyte interphase(SEI) film enriched with LiF and Li3 N was designed as a protective layer on Li anode(Li(SEI)) to suppress the growth of lithium dendrites.Benefiting from the synergy of sulfide-based composite solid electrolyte and ex-situ artificial SEI,cells of S-CNTs/LPSCI-PEO3-LiTFSI/Li(SEI) and Al_(2)O_(3)@LiNi_(0.5)Co_(0.3)Mn_(0.2)O_(2)/LPSCl-PEO3-LiTFSI/Li(SEI) are assembled and both exhibit high initial discharge capacity of 1221.1 mAh g^(-1)(135.8 mAh g^(-1)) and enhanced cycling stability with 81.6% capacity retention over 200 cycles at 0.05 C(89.2% over 100 cycles at 0.1 C).This work provides a new insight into the synergy of composite solid electrolyte and artificial SEI for achieving high-performance ASSLBs.展开更多
Chitosan-hydroxyapatite(CS-HA) composite powders were synthesized via in situ co-precipitation method,through the reaction of Ca(NO3)2 and H3PO4 in the simulated body fluid(SBF) containing appropriate amount of chitos...Chitosan-hydroxyapatite(CS-HA) composite powders were synthesized via in situ co-precipitation method,through the reaction of Ca(NO3)2 and H3PO4 in the simulated body fluid(SBF) containing appropriate amount of chitosan.The thermal evolution,microstructure and morphology were studied by TG-DTA(thermogravimetry-differential thermal analysis),XRD(X-ray diffraction),FTIR(Fourier transform infrared spectroscopy) and TEM(transmission electron microscopy).The in vitro bioactivity test showed that the obtained CS-HA composites had higher capability of inducing calcium ions deposition.Effects of CS-HA composites on the bioactivity and compressive strength of bioglass bone cement were investigated.The results indicated that the bioactivity of bioglass bone cement could be improved further when CS-HA composite powders were added into the cement,and appropriate amount of CS-HA additive was favorable for compressive strength improvement of bioglass bone cement.展开更多
To modify the surface property of poly lactide-co-glycolide (PLGA) by biomimetic mineralization to construct a new kind of artificial bone. PLGA films and 3-diamensional (3-D) porous scaffolds hydrolyzed in alkaline s...To modify the surface property of poly lactide-co-glycolide (PLGA) by biomimetic mineralization to construct a new kind of artificial bone. PLGA films and 3-diamensional (3-D) porous scaffolds hydrolyzed in alkaline solution were minerilized in SBF for 14 days. The morphology and composition of the mineral grown on PLGA were analyzed with SEM, FTIR and XRD. The porosity of the scaffolds was detected by using the liquid displacement method. The compressive strength of the scaffolds was detected by using a Shimadzu universal mechanic tester. An obvious mineral coating was detected on the surface of films and scaffolds. The main component of the mineral was carbonated hydroxyapatite (HA) similar to the major mineral component of bone tissues. The porosity of the un-mineralized and mineralized porous scaffolds was (84.86±8.52) % and (79.70±7.70) % respectively. The compressive strength was 0.784±0.156 N/mm 2 in un-mineralized 3-D porous PLGA and 0.858±0.145 N/mm 2 in mineralized 3-D porous PLGA. There were no significant differences between the mineralized and un-mineralized scaffolds (P>0.05) in porosity and biomechanics. Biomimetic mineralization is a suitable method to construct artificial bone.展开更多
AIM: To determine whether use of a precontoured olecranon plate provides adequate fixation to withstand supraphysiologic force in a comminuted olecranon fracture model.METHODS: Five samples of fourth generation compos...AIM: To determine whether use of a precontoured olecranon plate provides adequate fixation to withstand supraphysiologic force in a comminuted olecranon fracture model.METHODS: Five samples of fourth generation composite bones and five samples of fresh frozen human cadaveric left ulnae were utilized for this study. The cadaveric specimens underwent dual-energy X-ray absorptiometry(DEXA) scanning to quantify the bone quality. The composite and cadaveric bones were prepared by creating a comminuted olecranon fracture and fixed with a pre-contoured olecranon plate with locking screws. Construct stiffness and failure load were measured by subjecting specimens to cantilever bending moments until failure. Fracture site motion was measured with differential variable resistance transducer spanning the fracture. Statistical analysis was performed with two-tailed Mann-Whitney-U test with Monte Carlo Exact test.RESULTS: There was a significant difference in fixation stiffness and strength between the composite bones and human cadaver bones. Failure modes differed in cadaveric and composite specimens. The load to failure for the composite bones(n = 5) and human cadaver bones(n = 5) specimens were 10.67 nm(range 9.40-11.91 nm) and 13.05 nm(range 12.59-15.38 nm) respectively. This difference was statistically significant(P ? 0.007, 97% power). Median stiffness for composite bones and human cadaver bones specimens were 5.69 nm/mm(range 4.69-6.80 nm/mm) and 7.55 nm/mm(range 6.31-7.72 nm/mm). There was a significant difference for stiffness(P ? 0.033, 79% power) between composite bones and cadaveric bones. No correlation was found between the DEXA results and stiffness. All cadaveric specimens withstood the physiologic load anticipated postoperatively. Catastrophic failure occurred in all composite specimens. All failures resulted from composite bone failure at the distal screw site and not hardware failure. There were no catastrophic fracture failures in the cadaveric specimens. Failure of 4/5 cadaveric specimens was defined when a fracture gap of 2 mm was observed, but 1/5 cadaveric specimens failed due to a failure of the triceps mechanism. All failures occurred at forces greater than that expected in postoperative period prior to healing.CONCLUSION: The pre-contoured olecranon plate provides adequate fixation to withstand physiologic force in a composite bone and cadaveric comminuted olecranon fracture model.展开更多
This study presents the development of an innovative artificial finger-like device that provides position specific mechanical loads at the end of the long bone and induces mechanotransduction in bone. Bone cells such ...This study presents the development of an innovative artificial finger-like device that provides position specific mechanical loads at the end of the long bone and induces mechanotransduction in bone. Bone cells such as osteoblasts are the mechanosensitive cells that regulate bone remodelling. When they receive gentle, periodic mechanical loads, new bone formation is promoted. The proposed device is an under-actuated multi-fingered artificial hand with 4 fingers, each having two phalanges. These fingers are connected by mechanical linkages and operated by a worm gearing mechanism. With the help of 3D printing technology, a prototype device was built mostly using plastic materials. The experimental validation results show that the device is capable of generating necessary forces at the desired frequencies, which are suitable for the stimulation of bone cells and the promotion of bone formation. It is recommended that the device be tested in a clinical study for confirming its safety and efficacy with patients.展开更多
The combination of micro-carriers and polymer scaffolds as promising bone grafts have attracted considerable interest in recent decades.The poly(L-lactic acid)/poly(lactic-co-glycolic acid)/polycaprolactone(PLLA/PLGA/...The combination of micro-carriers and polymer scaffolds as promising bone grafts have attracted considerable interest in recent decades.The poly(L-lactic acid)/poly(lactic-co-glycolic acid)/polycaprolactone(PLLA/PLGA/PCL)composite scaffold with porous structure was fabricated by thermally induced phase separation(TIPS).Dexamethasone(DEX)was incorporated into PLGA microspheres and then loaded on the PLLA/PLGA/PCL scaffoldtopreparethedesiredcompositescaffold.The physicochemical properties of the prepared composite scaffold were characterized.The morphology of rat bone marrow mesenchymal stem cells(BMSCs)grown on scaffolds was observed using scanning electron microscope(SEM)and fluorescence microscope.The resultsshowedthatthePLLA/PLGA/PCLscaffoldhad interconnected macropores and biomimetic nanofibrous structure.In addition,DEX can be released from scaffold in a sustained manner.More importantly,DEX loaded composite scaffold can effectively support the proliferation of BMSCs as indicated by fluorescence observation and cell proliferation assay.The results suggested that the prepared PLLA/PLGA/PCL composite scaffold incorporating drug-loaded PLGA microspheres could hold great potential for bone tissue engineering applications.展开更多
In this work the influence of multiwalled carbon nanotubes (MWCNT) on mechanical properties was evaluated also the osteoinduction mechanism in Chitosan/MWCNT composite is reported. The morphology and the mechanical pr...In this work the influence of multiwalled carbon nanotubes (MWCNT) on mechanical properties was evaluated also the osteoinduction mechanism in Chitosan/MWCNT composite is reported. The morphology and the mechanical properties of the scaffolds were controlled by varying solvent ratios, quenching temperatures and carbon nanotubes concentration. In vitro cell culture of Sprague-Dawley rat’s osteoblasts was used to evaluate the phenotype expression of cells in the scaffolds. The presence of MWCNT in a chitosan matrix improving its mechanical properties and sustain osteoblast growth and differentiation that represent a potential application of the Chitosan/MWCNT as biomaterial for bone tissue engineering.展开更多
In this study the mechanical properties of bovine hydroxyapatite (BHA)-Li2O composites are predicted using artificial neural networks (ANN) and then compared with obtained experimental values. BHA was mixed with lithi...In this study the mechanical properties of bovine hydroxyapatite (BHA)-Li2O composites are predicted using artificial neural networks (ANN) and then compared with obtained experimental values. BHA was mixed with lithium carbonate (Li2CO3) and sintered at various temperatures between 900-1300°C. Selected experimental values obtained for the compression strength, microhardness and density were used to define and train the ANN system. Intermediate data values not used to train the ANN model were then used to compare and determine the reliability of the ANN system. The results demonstrate the viable potential in using the ANN approach in predicting mechanical properties even with limited data sets.展开更多
In recent years, aluminum-matrix composites (AMCs) have been widely used to replace cast iron in aerospace and automotive industries. Machining of these composite materials requires better understanding of cutting pro...In recent years, aluminum-matrix composites (AMCs) have been widely used to replace cast iron in aerospace and automotive industries. Machining of these composite materials requires better understanding of cutting processes re- garding accuracy and efficiency. This study addresses the modeling of the machinability of self-lubricated aluminum /alumina/graphite hybrid composites synthesized by the powder metallurgy method. In this study, multiple regression analysis (MRA) and artificial neural networks (ANN) were used to investigate the influence of some parameters on the thrust force and torque in the drilling processes of self-lubricated hybrid composite materials. The models were identi- fied by using cutting speed, feed, and volume fraction of the reinforcement particles as input data and the thrust force and torque as the output data. A comparison between two prediction methods was developed to compare the prediction accuracy. ANNs showed better predictability results compared to MRA due to the nonlinearity nature of ANNs. The statistical analysis accompanied with artificial neural network results showed that Al2O3, Gr and cutting feed (f) were the most significant parameters on the drilling process, while spindle speed seemed insignificant. Since the spindle speed was insignificant, it directed us to set it either at the highest spindle speed to obtain high material removal rate or at the lowest spindle speed to prolong the tool life depending on the need for the application.展开更多
Regenerative artificial bone material and bone parts were fabricated using vacuum-sintered bodies of a “titanium medical apatite (TMA?)” that is formed by chemically connecting Ti oxide molecules to the reactive [Ca...Regenerative artificial bone material and bone parts were fabricated using vacuum-sintered bodies of a “titanium medical apatite (TMA?)” that is formed by chemically connecting Ti oxide molecules to the reactive [Ca10 (PO4 )6 ] group of hydroxyapatite (HAp). Sintering at temperatures of 1273 - 1773 K caused this TMA sintered bodies to recrystallize and form a varying mix of α-TCP (tricalcium phosphate), β-TCP and Perovskite-CaTiO3 phases. The Perovskite crystals proved to be quite stable and hard, forming a uniform distribution of similarly sized fibers in all directions under vacuum sintering, but an irregular distribution and size when sintered in the presence of oxygen. Complete recrystallization was achieved by vacuum sintering at temperatures in excess of 1473 K. In particular, TMA vacuum-sintered bodies at 1573 K are given the maximum value;a Vickers hardness of 400, a bending strength of 43 MPa, a compressive strength of 270 MPa and a density of approximately 2300 kg/m3 was achieved that closely corresponds to that of compact bone or a tooth. As these TMA bodies could also be cut into various forms, they are considered a promising biomaterial for use as artificial bone in the regeneration of natural bone, or to provide reinforcement of bone junctions in dental and orthopedic surgery.展开更多
To develop synthesized coralline hydroxyl apatite (CHA) bone graftsubstitute and measure its physical and chemical characteristics. Methods: The CHA bone graft substitute was synthesized from natural mineral―corallin...To develop synthesized coralline hydroxyl apatite (CHA) bone graftsubstitute and measure its physical and chemical characteristics. Methods: The CHA bone graft substitute was synthesized from natural mineral―coralline through hydrothermal exchange process. This process was designed and developed independently by the authors. Its physical and chemical characteristics have been determined and studied using various techniques including Scanning Electron Microscopy (SEM), electron microscope image processing, scanning electron microscope energy spectrography; chemical analysis, ICP-AES, X-ray diffraction, etc. Clinical trials have been conducted. Results: Independently developed CHA bone graft-substitute is white in color; its porosity is 25.87%–53.58%, which is approximate to that of human bones and original coral. It is larger than 3–4 in hardness by Mohs hardness scale and the compressive strength ranges from 4.87 to 12.31 MPa. The chemical compositions of the CHA are 53.13%–64.09% CaO and 35.52%–46.48% P2O5. CaO/P2O5 is 1.143–1.804. ICP-AES analysis detected twenty-four trace elements including Pb, Co, Ni, Ba, Mn, Cr, Th, V, Cu, Ti, K, Mo, Zn, Mg, Nb, Be, Sc, Al, Sr, Na, Li, etc. Ca, P, K, Na, Al and Sr are relatively high while the rest are less than n–n×10-6, which is acceptable by human body. The REE level in the CHA bone measured by ICP-MS is 1.433×10-9–2.212×10-9, which is within the acceptable range for human beings. Conclusions: The process of synthesized CHA bone graft-substitute is an innovated independently developed method and concept. Its color, porosity and chemical composition are similar to those of human bones; therefore it has very good biocompatibility and excellent conductivity. Sixty clinical cases have proved that CHA bone graft-substitute has a strong bone-forming ability, no toxicity, no side effect, and better sacralization. It is a fine substitute for bone transplantation.展开更多
Layers of ante-polymerized PMMA(Polymethylmethacrylate) are manually smeared on both sides of carbon fiber and polyester fiber to a certain thickness. It was pre-solidified, stripped and cut for sterilization. Based o...Layers of ante-polymerized PMMA(Polymethylmethacrylate) are manually smeared on both sides of carbon fiber and polyester fiber to a certain thickness. It was pre-solidified, stripped and cut for sterilization. Based on the results of a series of experiments, HA coated artificial bone is considered to be a non-sensitizing, non-irritant, and non-toxic biomaterial for medical applications. The artificial bone has excellent mechanical and biological property. And it conforms to the national standard requirement. Safety analysis guarantees it a prosperous future of clinical application.展开更多
基金Clinical Study of Artificial Dermis Combined with Skin Flap Replacement Flap in Limb Wound Repair,No.WX21C27.
文摘BACKGROUND The recovery time of hand wounds is long,which can easily result in chronic and refractory wounds,making the wounds unable to be properly repaired.The treatment cycle is long,the cost is high,and it is prone to recurrence and disability.Double layer artificial dermis combined with autologous skin transplantation has been used to repair hypertrophic scars,deep burn wounds,exposed bone and tendon wounds,and post tumor wounds.AIM To investigate the therapeutic efficacy of autologous skin graft transplantation in conjunction with double-layer artificial dermis in treating finger skin wounds that are chronically refractory and soft tissue defects that expose bone and tendon.METHODS Sixty-eight chronic refractory patients with finger skin and soft tissue defects accompanied by bone and tendon exposure who were admitted from July 2021 to June 2022 were included in this study.The observation group was treated with double layer artificial dermis combined with autologous skin graft transplantation(n=49),while the control group was treated with pedicle skin flap transplantation(n=17).The treatment status of the two groups of patients was compared,including the time between surgeries and hospital stay.The survival rate of skin grafts/flaps and postoperative wound infections were evaluated using the Vancouver Scar Scale(VSS)for scar scoring at 6 mo after surgery,as well as the sensory injury grading method and two-point resolution test to assess the recovery of skin sensation at 6 mo.The satisfaction of the two groups of patients was also compared.RESULTS Wound healing time in the observation group was significantly longer than that in the control group(P<0.05,27.92±3.25 d vs 19.68±6.91 d);there was no significant difference in the survival rate of skin grafts/flaps between the two patient groups(P>0.05,95.1±5.0 vs 96.3±5.6).The interval between two surgeries(20.0±4.3 d)and hospital stay(21.0±10.1 d)in the observation group were both significantly shorter than those in the control group(27.5±9.3 d)and(28.4±17.7 d),respectively(P<0.05).In comparison to postoperative infection(23.5%)and subcutaneous hematoma(11.8%)in the control group,these were considerably lower at(10.2%)and(6.1%)in the observation group.When comparing the two patient groups at six months post-surgery,the excellent and good rate of sensory recovery(91.8%)was significantly higher in the observation group than in the control group(76.5%)(P<0.05).There was also no statistically significant difference in two point resolution(P>0.05).The VSS score in the observation group(2.91±1.36)was significantly lower than that in the control group(5.96±1.51),and group satisfaction was significantly higher(P<0.05,90.1±6.3 vs 76.3±5.2).CONCLUSION The combination of artificial dermis and autologous skin grafting for the treatment of hand tendon exposure wounds has a satisfactory therapeutic effect.It is a safe,effective,and easy to operate treatment method,which is worthy of clinical promotion.
文摘Objective: To investigate the application of artificial tiger bone powder on fracture healing time, wrist functional recovery and quality of life (QOL) in elderly patients with distal radius fracture. Methods: The study was a randomised controlled trials performed from January 2015 to December 2016 in a hospital. Elderly patients with distal radius fracture were divided into the treatment and the control groups by the random sealed envelope method. All patients were given splint or plaster fixation after manipulative reduction, and functional exercise, the treatment group was also given artificial tiger bone powder orally (trade name: Jintiange capsule), the control group was given an oral placebo in their appearance and usage identical with the treatment group. Prior to treatment and 6, 12 months after treatment, the wrist function was assessed by range of motion, including flexion-extension, radial-ulnar and pronation-supination, and the QOL was assessed by the Mos 36-item Short Form Health Survey. Each patient's fracture healing time was recorded. Results: Before treatment, there were no significant differences in wrist function and QOL between the two groups. At 6 and 12 months after treatment, the wrist function and QOL in the treatment group were better than those in the control group, the differences were statistically significant (P < 0.05). The fracture healing time in the treatment group was shorter than that of the control group, and the difference was statistically significant (P < 0.05). Conclusion: The early usage of artificial tiger bone powder for elderly patients with distal radius fracture can promote the healing of fracture, recovery of wrist joint function, and ultimately improve the QOL for elderly patients.
文摘In the present work, we report the first bionanocomposite material formed by otoliths/ collagen/ bacterial cellulose (BC) networks (OCBC). This biomaterial is an osteoinductor or be, stimulates the bone regeneration, enabling bigger migration of the cells for formation of the bone tissue regeneration mainly because nanotolith are rich in minerals considered essential to the bone mineralization process on a protein matrix (otolin). The objective in this study was to analyze the regeneration capacity of bone defects treated with this bionanocomposite. Histological experiments shows bone tissue formation with high regularity, higher osteoblast activity and osteo-reabsorption activities areas. The results suggest the potential for this new biomaterial as a scaffold for bone tissue regeneration.
文摘The aim of this study was to evaluate the outcome of autotransplantation or replantation of extracted teeth combining with reconstruction of alveolar bone defects in use of artificial bone grafting clinically and radiographically. This article presents a more useful and convenient method for repairing tooth and reconstruction of bone defecting with some interesting cases. Eleven patients (seven men and four women) in whom teeth with complete root formation were extracted and autotransplanted, the bone of receiving area was Insufficient. All transplanted teeth were stabilized with orthodontic wire and resin or 4-0 silk sutures;at the same time, artificial bone powder was filled. In 11 cases, the missing teeth were restored by autogenous teeth and the alveolar bone defect was restored by artificial bone, the improvement in the radiographic and clinical parameters strongly suggest that it may be a useful therapy to solve the problem of the missing teeth and alveolar bone insufficiency simultaneously. However, the risk of replacement root resorption remains.
基金financial supportfrom the National Natural Science Foundation of China(Grant Nos.51605220,U1637101)the Jiangsu Province NaturalScience Foundation(GrantNo.BK20160793)。
文摘Recently,researchers have concentrated on studying ionic polymer metal composite(IPMC)artificial muscle,which has numerous advantages including a relatively large strain under low input voltage,flexibility,high response,low noise,light weight,and high driving energy density.This paper reports recent developments in IPMC artificial muscle,including improvement methods,modeling,and applications.Different types of IPMCs are described,along with various methods for overcoming some shortcomings,including improvement of Nafion matrix membranes,surface preparation of Nafion membranes,the choice of high-performing electrodes,and new electro-active polymers for enhancing the properties of IPMCs.IPMC models are also reviewed,providing theoretical guidance for studying the performance and applications of IPMCs.Successful applications such as bio-inspired robots,opto-mechatronic systems,and medical engineering are discussed.
基金supported by the National Natural Science Foundation of China(51872027)the Fundamental Research Funds for the Central Universities(FRF-TP-20-014A2)。
文摘All-solid-state lithium batteries(ASSLBs) employing sulfide electrolyte and lithium(Li) anode have received increasing attention due to the intrinsic safety and high energy density.However,the thick electrolyte layer and lithium dendrites formed at the electrolyte/Li anode interface hinder the realization of high-performance ASSLBs.Herein,a novel membrane consisting of Li_(6)PS_(5) Cl(LPSCl),poly(ethylene oxide)(PEO) and Li-salt(LiTFSI) was prepared as sulfide-based composite solid electrolyte(LPSCl-PEO3-LiTFSI)(LPSCl:PEO=97:3 wt/wt;EO:Li=8:1 mol/mol),which delivers high ionic conductivity(1.1 × 10^(-3) S cm^(-1)) and wide electrochemical window(4.9 V vs.Li^(+)/Li) at 25 ℃.In addition,an ex-situ artificial solid electrolyte interphase(SEI) film enriched with LiF and Li3 N was designed as a protective layer on Li anode(Li(SEI)) to suppress the growth of lithium dendrites.Benefiting from the synergy of sulfide-based composite solid electrolyte and ex-situ artificial SEI,cells of S-CNTs/LPSCI-PEO3-LiTFSI/Li(SEI) and Al_(2)O_(3)@LiNi_(0.5)Co_(0.3)Mn_(0.2)O_(2)/LPSCl-PEO3-LiTFSI/Li(SEI) are assembled and both exhibit high initial discharge capacity of 1221.1 mAh g^(-1)(135.8 mAh g^(-1)) and enhanced cycling stability with 81.6% capacity retention over 200 cycles at 0.05 C(89.2% over 100 cycles at 0.1 C).This work provides a new insight into the synergy of composite solid electrolyte and artificial SEI for achieving high-performance ASSLBs.
基金supported by the Liaoning Province Doctoral Startup Foundation,China (No.20021054)the Liaoning Province Ministry Project of Education,China (No.202073425)
文摘Chitosan-hydroxyapatite(CS-HA) composite powders were synthesized via in situ co-precipitation method,through the reaction of Ca(NO3)2 and H3PO4 in the simulated body fluid(SBF) containing appropriate amount of chitosan.The thermal evolution,microstructure and morphology were studied by TG-DTA(thermogravimetry-differential thermal analysis),XRD(X-ray diffraction),FTIR(Fourier transform infrared spectroscopy) and TEM(transmission electron microscopy).The in vitro bioactivity test showed that the obtained CS-HA composites had higher capability of inducing calcium ions deposition.Effects of CS-HA composites on the bioactivity and compressive strength of bioglass bone cement were investigated.The results indicated that the bioactivity of bioglass bone cement could be improved further when CS-HA composite powders were added into the cement,and appropriate amount of CS-HA additive was favorable for compressive strength improvement of bioglass bone cement.
文摘To modify the surface property of poly lactide-co-glycolide (PLGA) by biomimetic mineralization to construct a new kind of artificial bone. PLGA films and 3-diamensional (3-D) porous scaffolds hydrolyzed in alkaline solution were minerilized in SBF for 14 days. The morphology and composition of the mineral grown on PLGA were analyzed with SEM, FTIR and XRD. The porosity of the scaffolds was detected by using the liquid displacement method. The compressive strength of the scaffolds was detected by using a Shimadzu universal mechanic tester. An obvious mineral coating was detected on the surface of films and scaffolds. The main component of the mineral was carbonated hydroxyapatite (HA) similar to the major mineral component of bone tissues. The porosity of the un-mineralized and mineralized porous scaffolds was (84.86±8.52) % and (79.70±7.70) % respectively. The compressive strength was 0.784±0.156 N/mm 2 in un-mineralized 3-D porous PLGA and 0.858±0.145 N/mm 2 in mineralized 3-D porous PLGA. There were no significant differences between the mineralized and un-mineralized scaffolds (P>0.05) in porosity and biomechanics. Biomimetic mineralization is a suitable method to construct artificial bone.
文摘AIM: To determine whether use of a precontoured olecranon plate provides adequate fixation to withstand supraphysiologic force in a comminuted olecranon fracture model.METHODS: Five samples of fourth generation composite bones and five samples of fresh frozen human cadaveric left ulnae were utilized for this study. The cadaveric specimens underwent dual-energy X-ray absorptiometry(DEXA) scanning to quantify the bone quality. The composite and cadaveric bones were prepared by creating a comminuted olecranon fracture and fixed with a pre-contoured olecranon plate with locking screws. Construct stiffness and failure load were measured by subjecting specimens to cantilever bending moments until failure. Fracture site motion was measured with differential variable resistance transducer spanning the fracture. Statistical analysis was performed with two-tailed Mann-Whitney-U test with Monte Carlo Exact test.RESULTS: There was a significant difference in fixation stiffness and strength between the composite bones and human cadaver bones. Failure modes differed in cadaveric and composite specimens. The load to failure for the composite bones(n = 5) and human cadaver bones(n = 5) specimens were 10.67 nm(range 9.40-11.91 nm) and 13.05 nm(range 12.59-15.38 nm) respectively. This difference was statistically significant(P ? 0.007, 97% power). Median stiffness for composite bones and human cadaver bones specimens were 5.69 nm/mm(range 4.69-6.80 nm/mm) and 7.55 nm/mm(range 6.31-7.72 nm/mm). There was a significant difference for stiffness(P ? 0.033, 79% power) between composite bones and cadaveric bones. No correlation was found between the DEXA results and stiffness. All cadaveric specimens withstood the physiologic load anticipated postoperatively. Catastrophic failure occurred in all composite specimens. All failures resulted from composite bone failure at the distal screw site and not hardware failure. There were no catastrophic fracture failures in the cadaveric specimens. Failure of 4/5 cadaveric specimens was defined when a fracture gap of 2 mm was observed, but 1/5 cadaveric specimens failed due to a failure of the triceps mechanism. All failures occurred at forces greater than that expected in postoperative period prior to healing.CONCLUSION: The pre-contoured olecranon plate provides adequate fixation to withstand physiologic force in a composite bone and cadaveric comminuted olecranon fracture model.
文摘This study presents the development of an innovative artificial finger-like device that provides position specific mechanical loads at the end of the long bone and induces mechanotransduction in bone. Bone cells such as osteoblasts are the mechanosensitive cells that regulate bone remodelling. When they receive gentle, periodic mechanical loads, new bone formation is promoted. The proposed device is an under-actuated multi-fingered artificial hand with 4 fingers, each having two phalanges. These fingers are connected by mechanical linkages and operated by a worm gearing mechanism. With the help of 3D printing technology, a prototype device was built mostly using plastic materials. The experimental validation results show that the device is capable of generating necessary forces at the desired frequencies, which are suitable for the stimulation of bone cells and the promotion of bone formation. It is recommended that the device be tested in a clinical study for confirming its safety and efficacy with patients.
基金National Natural Science Foundations of China(Nos.31271028,31570984)Innovation Program of Shanghai Municipal Education Commission,China(No.13ZZ051)+2 种基金International Cooperation Fund of the Science and Technology Commission of Shanghai Municipality,China(No.15540723400)Open Foundation of State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,China(No.LK1416)“111 Project” Biomedical Textile Materials Science and Technology,China(No.B07024)
文摘The combination of micro-carriers and polymer scaffolds as promising bone grafts have attracted considerable interest in recent decades.The poly(L-lactic acid)/poly(lactic-co-glycolic acid)/polycaprolactone(PLLA/PLGA/PCL)composite scaffold with porous structure was fabricated by thermally induced phase separation(TIPS).Dexamethasone(DEX)was incorporated into PLGA microspheres and then loaded on the PLLA/PLGA/PCL scaffoldtopreparethedesiredcompositescaffold.The physicochemical properties of the prepared composite scaffold were characterized.The morphology of rat bone marrow mesenchymal stem cells(BMSCs)grown on scaffolds was observed using scanning electron microscope(SEM)and fluorescence microscope.The resultsshowedthatthePLLA/PLGA/PCLscaffoldhad interconnected macropores and biomimetic nanofibrous structure.In addition,DEX can be released from scaffold in a sustained manner.More importantly,DEX loaded composite scaffold can effectively support the proliferation of BMSCs as indicated by fluorescence observation and cell proliferation assay.The results suggested that the prepared PLLA/PLGA/PCL composite scaffold incorporating drug-loaded PLGA microspheres could hold great potential for bone tissue engineering applications.
文摘In this work the influence of multiwalled carbon nanotubes (MWCNT) on mechanical properties was evaluated also the osteoinduction mechanism in Chitosan/MWCNT composite is reported. The morphology and the mechanical properties of the scaffolds were controlled by varying solvent ratios, quenching temperatures and carbon nanotubes concentration. In vitro cell culture of Sprague-Dawley rat’s osteoblasts was used to evaluate the phenotype expression of cells in the scaffolds. The presence of MWCNT in a chitosan matrix improving its mechanical properties and sustain osteoblast growth and differentiation that represent a potential application of the Chitosan/MWCNT as biomaterial for bone tissue engineering.
文摘In this study the mechanical properties of bovine hydroxyapatite (BHA)-Li2O composites are predicted using artificial neural networks (ANN) and then compared with obtained experimental values. BHA was mixed with lithium carbonate (Li2CO3) and sintered at various temperatures between 900-1300°C. Selected experimental values obtained for the compression strength, microhardness and density were used to define and train the ANN system. Intermediate data values not used to train the ANN model were then used to compare and determine the reliability of the ANN system. The results demonstrate the viable potential in using the ANN approach in predicting mechanical properties even with limited data sets.
文摘In recent years, aluminum-matrix composites (AMCs) have been widely used to replace cast iron in aerospace and automotive industries. Machining of these composite materials requires better understanding of cutting processes re- garding accuracy and efficiency. This study addresses the modeling of the machinability of self-lubricated aluminum /alumina/graphite hybrid composites synthesized by the powder metallurgy method. In this study, multiple regression analysis (MRA) and artificial neural networks (ANN) were used to investigate the influence of some parameters on the thrust force and torque in the drilling processes of self-lubricated hybrid composite materials. The models were identi- fied by using cutting speed, feed, and volume fraction of the reinforcement particles as input data and the thrust force and torque as the output data. A comparison between two prediction methods was developed to compare the prediction accuracy. ANNs showed better predictability results compared to MRA due to the nonlinearity nature of ANNs. The statistical analysis accompanied with artificial neural network results showed that Al2O3, Gr and cutting feed (f) were the most significant parameters on the drilling process, while spindle speed seemed insignificant. Since the spindle speed was insignificant, it directed us to set it either at the highest spindle speed to obtain high material removal rate or at the lowest spindle speed to prolong the tool life depending on the need for the application.
文摘Regenerative artificial bone material and bone parts were fabricated using vacuum-sintered bodies of a “titanium medical apatite (TMA?)” that is formed by chemically connecting Ti oxide molecules to the reactive [Ca10 (PO4 )6 ] group of hydroxyapatite (HAp). Sintering at temperatures of 1273 - 1773 K caused this TMA sintered bodies to recrystallize and form a varying mix of α-TCP (tricalcium phosphate), β-TCP and Perovskite-CaTiO3 phases. The Perovskite crystals proved to be quite stable and hard, forming a uniform distribution of similarly sized fibers in all directions under vacuum sintering, but an irregular distribution and size when sintered in the presence of oxygen. Complete recrystallization was achieved by vacuum sintering at temperatures in excess of 1473 K. In particular, TMA vacuum-sintered bodies at 1573 K are given the maximum value;a Vickers hardness of 400, a bending strength of 43 MPa, a compressive strength of 270 MPa and a density of approximately 2300 kg/m3 was achieved that closely corresponds to that of compact bone or a tooth. As these TMA bodies could also be cut into various forms, they are considered a promising biomaterial for use as artificial bone in the regeneration of natural bone, or to provide reinforcement of bone junctions in dental and orthopedic surgery.
基金supportedby the funds from both Science-Technology Department of Guangdong and Science-Technology Department of Guangzhou
文摘To develop synthesized coralline hydroxyl apatite (CHA) bone graftsubstitute and measure its physical and chemical characteristics. Methods: The CHA bone graft substitute was synthesized from natural mineral―coralline through hydrothermal exchange process. This process was designed and developed independently by the authors. Its physical and chemical characteristics have been determined and studied using various techniques including Scanning Electron Microscopy (SEM), electron microscope image processing, scanning electron microscope energy spectrography; chemical analysis, ICP-AES, X-ray diffraction, etc. Clinical trials have been conducted. Results: Independently developed CHA bone graft-substitute is white in color; its porosity is 25.87%–53.58%, which is approximate to that of human bones and original coral. It is larger than 3–4 in hardness by Mohs hardness scale and the compressive strength ranges from 4.87 to 12.31 MPa. The chemical compositions of the CHA are 53.13%–64.09% CaO and 35.52%–46.48% P2O5. CaO/P2O5 is 1.143–1.804. ICP-AES analysis detected twenty-four trace elements including Pb, Co, Ni, Ba, Mn, Cr, Th, V, Cu, Ti, K, Mo, Zn, Mg, Nb, Be, Sc, Al, Sr, Na, Li, etc. Ca, P, K, Na, Al and Sr are relatively high while the rest are less than n–n×10-6, which is acceptable by human body. The REE level in the CHA bone measured by ICP-MS is 1.433×10-9–2.212×10-9, which is within the acceptable range for human beings. Conclusions: The process of synthesized CHA bone graft-substitute is an innovated independently developed method and concept. Its color, porosity and chemical composition are similar to those of human bones; therefore it has very good biocompatibility and excellent conductivity. Sixty clinical cases have proved that CHA bone graft-substitute has a strong bone-forming ability, no toxicity, no side effect, and better sacralization. It is a fine substitute for bone transplantation.
文摘Layers of ante-polymerized PMMA(Polymethylmethacrylate) are manually smeared on both sides of carbon fiber and polyester fiber to a certain thickness. It was pre-solidified, stripped and cut for sterilization. Based on the results of a series of experiments, HA coated artificial bone is considered to be a non-sensitizing, non-irritant, and non-toxic biomaterial for medical applications. The artificial bone has excellent mechanical and biological property. And it conforms to the national standard requirement. Safety analysis guarantees it a prosperous future of clinical application.
