3D printing has made remarkable progress in soft tissue reconstruction enabling the custom design of complex material implants with patient specific geometry.The aim of this study was to inkjet print mechanically rein...3D printing has made remarkable progress in soft tissue reconstruction enabling the custom design of complex material implants with patient specific geometry.The aim of this study was to inkjet print mechanically reinforced biocompatible hydrogels.Here,we developed a double crosslinked ink by optimizing the rheological properties of solutions of sodium alginate(NaAlg),NaAlg/transglutaminase(TG),CaCl_(2)and gelatin/CaCl_(2).The results showed that a two-component ink system comprising NaAlg(4%w/v)/TG(0.8%w/v)and gelatin(4%w/v)/CaCl_(2)(3%w/v)gave optimum printability.The mechanical and biological properties of printed alginate/gelatin hydrogels prepared from inks with different gelatin contents,and incorporated fibroblasts,were characterized by Scanning Electron Microscope(SEM),mechanical testing and laser confocal microscopy.The compressive moduli of alginate/gelatin hydrogels could be adjusted from 19.2 kPa±1.2 kPa to 65.9 kPa±3.3 kPa by increasing the content of gelatin.After incubation for 7 d,fibroblasts had permeated all printed hydrogels and the rate of proliferation increased with increasing gelatin content.The highest cell proliferation rate(497%)was obtained in a hydrogel containing 4.5%(w/v)gelatin.This study offers a new strategy for the fabrication of 3D structures used to mimic the function of native tissues.展开更多
The shortage of skin for grafting continues to be a major problem in the treatment of serious skin injuries.3D bioprinting provides a new way to solve this problem.However,current 3D printed skin is less effective in ...The shortage of skin for grafting continues to be a major problem in the treatment of serious skin injuries.3D bioprinting provides a new way to solve this problem.However,current 3D printed skin is less effective in treatment of large wounds because of severe shrinkage and scarring.In this study,bionically designed bilayer skin was fabricated using an extrusion-based bioprinter and a gelatin/sodium alginate/gelatin methacrylate hydrogel with excellent physical and biological properties.Full-thickness skin wounds were created in the back of nude mice and treated with bioprinted skin or hydrogel.Bioprinted skin accelerated wound healing,reduced wound contraction and scarring,and facilitated wound skin epithelialization compared with the bioprinted hydrogel or untreated wound.The skin from the wound was collected 28 days after grafting for histology and immunofluorescence analysis.The thickness of the dermis and epidermis of the bioprinted skin was similar to that of nude mice.Microvascular formation in the dermis and dense keratinocytes in the epidermis of the bioprinted skin were observed.This study provides a potential treatment strategy for reducing skin contraction and scar in large skin wounds.展开更多
基金This work was supported by the Development Projects of Key Research(No.2018YFE0207900)People’s Liberation Army(No.BWS17J036,18-163-13-ZT-003-011-01)the National Natural Science Foundation of China(Nos.51835010 and 51375371).
文摘3D printing has made remarkable progress in soft tissue reconstruction enabling the custom design of complex material implants with patient specific geometry.The aim of this study was to inkjet print mechanically reinforced biocompatible hydrogels.Here,we developed a double crosslinked ink by optimizing the rheological properties of solutions of sodium alginate(NaAlg),NaAlg/transglutaminase(TG),CaCl_(2)and gelatin/CaCl_(2).The results showed that a two-component ink system comprising NaAlg(4%w/v)/TG(0.8%w/v)and gelatin(4%w/v)/CaCl_(2)(3%w/v)gave optimum printability.The mechanical and biological properties of printed alginate/gelatin hydrogels prepared from inks with different gelatin contents,and incorporated fibroblasts,were characterized by Scanning Electron Microscope(SEM),mechanical testing and laser confocal microscopy.The compressive moduli of alginate/gelatin hydrogels could be adjusted from 19.2 kPa±1.2 kPa to 65.9 kPa±3.3 kPa by increasing the content of gelatin.After incubation for 7 d,fibroblasts had permeated all printed hydrogels and the rate of proliferation increased with increasing gelatin content.The highest cell proliferation rate(497%)was obtained in a hydrogel containing 4.5%(w/v)gelatin.This study offers a new strategy for the fabrication of 3D structures used to mimic the function of native tissues.
基金This work was supported by the National Key R&D Program of China(No.2018YFE0207900)the Development projects of Key research of People’s Liberation Army(No.BWS17J036,18-163-13-ZT-003-011-01)the National Natural Science Foundation of China(51835010 and 51375371)。
文摘The shortage of skin for grafting continues to be a major problem in the treatment of serious skin injuries.3D bioprinting provides a new way to solve this problem.However,current 3D printed skin is less effective in treatment of large wounds because of severe shrinkage and scarring.In this study,bionically designed bilayer skin was fabricated using an extrusion-based bioprinter and a gelatin/sodium alginate/gelatin methacrylate hydrogel with excellent physical and biological properties.Full-thickness skin wounds were created in the back of nude mice and treated with bioprinted skin or hydrogel.Bioprinted skin accelerated wound healing,reduced wound contraction and scarring,and facilitated wound skin epithelialization compared with the bioprinted hydrogel or untreated wound.The skin from the wound was collected 28 days after grafting for histology and immunofluorescence analysis.The thickness of the dermis and epidermis of the bioprinted skin was similar to that of nude mice.Microvascular formation in the dermis and dense keratinocytes in the epidermis of the bioprinted skin were observed.This study provides a potential treatment strategy for reducing skin contraction and scar in large skin wounds.
