Current hemostatic agents or dressings are not efficient under extremely hot and cold environments due to deterioration of active ingredients,water evaporation and ice crystal growth.To address these challenges,we eng...Current hemostatic agents or dressings are not efficient under extremely hot and cold environments due to deterioration of active ingredients,water evaporation and ice crystal growth.To address these challenges,we engineered a biocompatible hemostatic system with thermoregulatory properties for harsh conditions by combining the asymmetric wetting nano-silica aerogel coated-gauze(AWNSA@G)with a layer-by-layer(LBL)structure.Our AWNSA@G was a dressing with a tunable wettability prepared by spraying the hydrophobic nano-silica aerogel onto the gauze from different distances.The hemostatic time and blood loss of the AWNSA@G were 5.1 and 6.9 times lower than normal gauze in rat’s injured femoral artery model.Moreover,the modified gauze was torn off after hemostasis without rebleeding,approximately 23.8 times of peak peeling force lower than normal gauze.For the LBL structure,consisting of the nano-silica aerogel layer and a n-octadecane phase change material layer,in both hot(70℃)and cold(-27℃)environments,exhibited dual-functional thermal management and maintained a stable internal temperature.We further verified our composite presented superior blood coagulation effect in extreme environments due to the LBL structure,the pro-coagulant properties of nano-silica aerogel and unidirectional fluid pumping of AWNSA@G.Our work,therefore,shows great hemostasis potential under normal and extreme temperature environments.展开更多
3D printing,an additive manufacturing based technology for precise 3D construction,is currently widely employed to enhance applicability and function of cell laden scaffolds.Research on novel compatible biomaterials f...3D printing,an additive manufacturing based technology for precise 3D construction,is currently widely employed to enhance applicability and function of cell laden scaffolds.Research on novel compatible biomaterials for bioprinting exhibiting fast crosslinking properties is an essential prerequisite toward advancing 3D printing applications in tissue engineering.Printability to improve fabrication process and cell encapsulation are two of the main factors to be considered in development of 3D bioprinting.Other important factors include but are not limited to printing fidelity,stability,crosslinking time,biocompatibility,cell encapsulation and proliferation,shear-thinning properties,and mechanical properties such as mechanical strength and elasticity.In this review,we recite recent promising advances in bioink development as well as bioprinting methods.Also,an effort has been made to include studies with diverse types of crosslinking methods such as photo,chemical and ultraviolet(UV).We also propose the challenges and future outlook of 3D bioprinting application in medical sciences and discuss the high performance bioinks.展开更多
Endoscopic submucosal dissection(ESD)is a common procedure to treat early and precancerous gastrointestinal lesions.Via submucosal injection,a liquid cushion is created to lift and separate the lesion and malignant pa...Endoscopic submucosal dissection(ESD)is a common procedure to treat early and precancerous gastrointestinal lesions.Via submucosal injection,a liquid cushion is created to lift and separate the lesion and malignant part from the muscular layer where the formed indispensable space is convenient for endoscopic incision.Saline is a most common submucosal injection liquid,but the formed liquid pad lasts only a short time,and thus repeated injections increase the potential risk of adverse events.Hydrogels with high osmotic pressure and high viscosity are used as an alternate;however,with some drawbacks such as tissue damage,excessive injection resistance,and high cost.Here,we reported a nature derived hydrogel of gelatin-oxidized alginate(G-OALG).Based on the rheological analysis and compare to commercial endoscopic mucosal resection(EMR)solution(0.25%hyaluronic acid,HA),a designed G-OALG hydrogel of desired concentration and composition showed higher performances in controllable gelation and injectability,higher viscosity and more stable structures.The G-OALG gel also showed lower propulsion resistance than 0.25%HA in the injection force assessment under standard endoscopic instruments,which eased the surgical operation.In addition,the G-OALG hydrogel showed good in vivo degradability biocompatibility.By comparing the results acquired via ESD to normal saline,the G-OALG shows great histocompatibility and excellent endoscopic injectability,and enables create a longer-lasting submucosal cushion.All the features have been confirmed in the living both pig and rat models.The G-OALG could be a promising submucosal injection agent for esophageal ESD.展开更多
Background: Bacterial infection is one of the most common complications in burn, trauma, and chronic refractory wounds and is an impediment to healing. The frequent occurrence of antimicrobial-resistant bacteria due t...Background: Bacterial infection is one of the most common complications in burn, trauma, and chronic refractory wounds and is an impediment to healing. The frequent occurrence of antimicrobial-resistant bacteria due to irrational application of antibiotics increases treatment cost and mortality. Graphene oxide (GO) has been generally reported to possess high antimicrobial activity against a wide range of bacteria in vitro. In this study, a graphene oxide-quaternary ammonium salt (GO-QAS) nanocomposite was synthesized and thoroughly investigated for synergistic antibacterial activity, underlying antibacterial mechanisms and biocompatibility in vitro and in vivo. Methods: The GO-QAS nanocomposite was synthesized through amidation reactions of carboxylic group end-capped QAS polymers with primary amine-decorated GO to achieve high QAS loading ratios on nanosheets. Next, we investigated the antibacterial activity and biocompatibility of GO-QAS in vitro and in vivo. Results: GO-QAS exhibited synergistic antibacterial activity against bacteria through not only mechanical membrane perturbation, including wrapping, bacterial membrane insertion, and bacterial membrane perforation, but also oxidative stress induction. In addition, it was found that GO-QAS could eradicate multidrug-resistant bacteria more effectively than conventional antibiotics. The in vitro and in vivo toxicity tests indicated that GO-QAS did not exhibit obvious toxicity towards mammalian cel s or organs at low concentrations. Notably, GO-QAS topically applied on infected wounds maintained highly efficient antibacterial activity and promoted infected wound healing in vivo. Conclusions: The GO-QAS nanocomposite exhibits excellent synergistic antibacterial activity and good biocompatibility both in vitro and in vivo. The antibacterial mechanisms involve both mechanical membrane perturbation and oxidative stress induction. In addition, GO-QAS accelerated the healing process of infected wounds by promoting re-epithelialization and granulation tissue formation. Overall, the results indicated that the GO-QAS nanocomposite could be applied as a promising antimicrobial agent for infected wound management and antibacterial wound dressing synthesis.展开更多
Bioadhesives act as a bridge in wound closure by forming an effective interface to protect against liquid and gas leakage and aid the stoppage of bleeding.To their credit,tissue adhesives have made an indelible impact...Bioadhesives act as a bridge in wound closure by forming an effective interface to protect against liquid and gas leakage and aid the stoppage of bleeding.To their credit,tissue adhesives have made an indelible impact on almost all wound-related surgeries.Their unique properties include minimal damage to tissues,low chance of infection,ease of use and short wound-closure time.In contrast,classic closures,like suturing and stapling,exhibit potential additional complications with long operation times and undesirable inflammatory responses.Although tremendous progress has been made in the development of tissue adhesives,they are not yet ideal.Therefore,highlighting and summarizing existing adhesive designs and synthesis,and comparing the different products will contribute to future development.This review first provides a summary of current commercial traditional tissue adhesives.Then,based on adhesion interaction mechanisms,the tissue adhesives are categorized into three main types:adhesive patches that bind molecularly with tissue,tissuestitching adhesives based on pre-polymer or precursor solutions,and bioinspired or biomimetic tissue adhesives.Their specific adhesion mechanisms,properties and related applications are discussed.The adhesion mechanisms of commercial traditional adhesives as well as their limitations and shortcomings are also reviewed.Finally,we also discuss the future perspectives of tissue adhesives.展开更多
基金granted approval by the Animal Ethics Committee of Jiangnan University(Protocol JN.No 20220615S0801025).
文摘Current hemostatic agents or dressings are not efficient under extremely hot and cold environments due to deterioration of active ingredients,water evaporation and ice crystal growth.To address these challenges,we engineered a biocompatible hemostatic system with thermoregulatory properties for harsh conditions by combining the asymmetric wetting nano-silica aerogel coated-gauze(AWNSA@G)with a layer-by-layer(LBL)structure.Our AWNSA@G was a dressing with a tunable wettability prepared by spraying the hydrophobic nano-silica aerogel onto the gauze from different distances.The hemostatic time and blood loss of the AWNSA@G were 5.1 and 6.9 times lower than normal gauze in rat’s injured femoral artery model.Moreover,the modified gauze was torn off after hemostasis without rebleeding,approximately 23.8 times of peak peeling force lower than normal gauze.For the LBL structure,consisting of the nano-silica aerogel layer and a n-octadecane phase change material layer,in both hot(70℃)and cold(-27℃)environments,exhibited dual-functional thermal management and maintained a stable internal temperature.We further verified our composite presented superior blood coagulation effect in extreme environments due to the LBL structure,the pro-coagulant properties of nano-silica aerogel and unidirectional fluid pumping of AWNSA@G.Our work,therefore,shows great hemostasis potential under normal and extreme temperature environments.
基金Authors want to thank the funding support of National Sciences and Engineering Research Council of Canada(NSERC)Discovery Grant,NSERC Accelerator Supplement Award and Canada Foundation for Innovation,and the research support of Hkable3D for 3D printers.
文摘3D printing,an additive manufacturing based technology for precise 3D construction,is currently widely employed to enhance applicability and function of cell laden scaffolds.Research on novel compatible biomaterials for bioprinting exhibiting fast crosslinking properties is an essential prerequisite toward advancing 3D printing applications in tissue engineering.Printability to improve fabrication process and cell encapsulation are two of the main factors to be considered in development of 3D bioprinting.Other important factors include but are not limited to printing fidelity,stability,crosslinking time,biocompatibility,cell encapsulation and proliferation,shear-thinning properties,and mechanical properties such as mechanical strength and elasticity.In this review,we recite recent promising advances in bioink development as well as bioprinting methods.Also,an effort has been made to include studies with diverse types of crosslinking methods such as photo,chemical and ultraviolet(UV).We also propose the challenges and future outlook of 3D bioprinting application in medical sciences and discuss the high performance bioinks.
基金the the National Science Foundation of China(No.81802982)ChongQing Science&Technology Commission Fund(No.CSTC2018jcyjAX0102).
文摘Endoscopic submucosal dissection(ESD)is a common procedure to treat early and precancerous gastrointestinal lesions.Via submucosal injection,a liquid cushion is created to lift and separate the lesion and malignant part from the muscular layer where the formed indispensable space is convenient for endoscopic incision.Saline is a most common submucosal injection liquid,but the formed liquid pad lasts only a short time,and thus repeated injections increase the potential risk of adverse events.Hydrogels with high osmotic pressure and high viscosity are used as an alternate;however,with some drawbacks such as tissue damage,excessive injection resistance,and high cost.Here,we reported a nature derived hydrogel of gelatin-oxidized alginate(G-OALG).Based on the rheological analysis and compare to commercial endoscopic mucosal resection(EMR)solution(0.25%hyaluronic acid,HA),a designed G-OALG hydrogel of desired concentration and composition showed higher performances in controllable gelation and injectability,higher viscosity and more stable structures.The G-OALG gel also showed lower propulsion resistance than 0.25%HA in the injection force assessment under standard endoscopic instruments,which eased the surgical operation.In addition,the G-OALG hydrogel showed good in vivo degradability biocompatibility.By comparing the results acquired via ESD to normal saline,the G-OALG shows great histocompatibility and excellent endoscopic injectability,and enables create a longer-lasting submucosal cushion.All the features have been confirmed in the living both pig and rat models.The G-OALG could be a promising submucosal injection agent for esophageal ESD.
基金the Southwest Hospital Key Program(SWH2016ZDCX2014)National Natural Science Foundation of China(81372082)+1 种基金National Special Scientific Projects of Public Welfare Industry Funding of China(201502028)the State Key Laboratory Funding(SKLZZ201221).
文摘Background: Bacterial infection is one of the most common complications in burn, trauma, and chronic refractory wounds and is an impediment to healing. The frequent occurrence of antimicrobial-resistant bacteria due to irrational application of antibiotics increases treatment cost and mortality. Graphene oxide (GO) has been generally reported to possess high antimicrobial activity against a wide range of bacteria in vitro. In this study, a graphene oxide-quaternary ammonium salt (GO-QAS) nanocomposite was synthesized and thoroughly investigated for synergistic antibacterial activity, underlying antibacterial mechanisms and biocompatibility in vitro and in vivo. Methods: The GO-QAS nanocomposite was synthesized through amidation reactions of carboxylic group end-capped QAS polymers with primary amine-decorated GO to achieve high QAS loading ratios on nanosheets. Next, we investigated the antibacterial activity and biocompatibility of GO-QAS in vitro and in vivo. Results: GO-QAS exhibited synergistic antibacterial activity against bacteria through not only mechanical membrane perturbation, including wrapping, bacterial membrane insertion, and bacterial membrane perforation, but also oxidative stress induction. In addition, it was found that GO-QAS could eradicate multidrug-resistant bacteria more effectively than conventional antibiotics. The in vitro and in vivo toxicity tests indicated that GO-QAS did not exhibit obvious toxicity towards mammalian cel s or organs at low concentrations. Notably, GO-QAS topically applied on infected wounds maintained highly efficient antibacterial activity and promoted infected wound healing in vivo. Conclusions: The GO-QAS nanocomposite exhibits excellent synergistic antibacterial activity and good biocompatibility both in vitro and in vivo. The antibacterial mechanisms involve both mechanical membrane perturbation and oxidative stress induction. In addition, GO-QAS accelerated the healing process of infected wounds by promoting re-epithelialization and granulation tissue formation. Overall, the results indicated that the GO-QAS nanocomposite could be applied as a promising antimicrobial agent for infected wound management and antibacterial wound dressing synthesis.
基金supported by the National Key Research and Development Project(2016YFB0303201)the Research and Innovation Project of Shanghai Municipal Education Commission(14zz069)Donghua University Graduates'Innovation Funding Projects(EG2015006)
文摘Bioadhesives act as a bridge in wound closure by forming an effective interface to protect against liquid and gas leakage and aid the stoppage of bleeding.To their credit,tissue adhesives have made an indelible impact on almost all wound-related surgeries.Their unique properties include minimal damage to tissues,low chance of infection,ease of use and short wound-closure time.In contrast,classic closures,like suturing and stapling,exhibit potential additional complications with long operation times and undesirable inflammatory responses.Although tremendous progress has been made in the development of tissue adhesives,they are not yet ideal.Therefore,highlighting and summarizing existing adhesive designs and synthesis,and comparing the different products will contribute to future development.This review first provides a summary of current commercial traditional tissue adhesives.Then,based on adhesion interaction mechanisms,the tissue adhesives are categorized into three main types:adhesive patches that bind molecularly with tissue,tissuestitching adhesives based on pre-polymer or precursor solutions,and bioinspired or biomimetic tissue adhesives.Their specific adhesion mechanisms,properties and related applications are discussed.The adhesion mechanisms of commercial traditional adhesives as well as their limitations and shortcomings are also reviewed.Finally,we also discuss the future perspectives of tissue adhesives.
