Bioprinting has been widely investigated for tissue engineering and regenerative medicine applications.However,it is still difficult to reconstruct the complex native cell arrangement due to the limited printing resol...Bioprinting has been widely investigated for tissue engineering and regenerative medicine applications.However,it is still difficult to reconstruct the complex native cell arrangement due to the limited printing resolution of conventional bioprinting techniques such as extrusion-and inkjet-based printing.Recently,an electrohydrodynamic(EHD)bioprinting strategy was reported for the precise deposition of well-organized cell-laden constructs with microscale filament size,whereas few studies have been devoted to developing bioinks that can be applied for EHD bioprinting and simultaneously support cell spreading.This study describes functionalized alginate-based bioinks for microscale EHD bioprinting using peptide grafting and fibrin incorporation,which leads to high cell viability(>90%)and cell spreading.The printed filaments can be further refined to as small as 30μm by incorporating polyoxyethylene and remained stable over one week when exposed to an aqueous environment.By utilizing the presented alginate-based bioinks,layer-specific cell alignment along the printing struts could be observed inside the EHD-printed microscale filaments,which allows fabricating living constructs with cell-scale filament resolution for guided cellular orientation.展开更多
Metakaolin(MK)and sodium alginate(SA)were employed as raw materials to prepare SA-MK geopolymers,which were inorganic/organic composites.The microscopic morphologies,mineral phases,and chemical bonds of these composit...Metakaolin(MK)and sodium alginate(SA)were employed as raw materials to prepare SA-MK geopolymers,which were inorganic/organic composites.The microscopic morphologies,mineral phases,and chemical bonds of these composites were examined using mercury intrusion porosimetry,X-ray diffraction,Fourier-transform infrared spectroscopy,and scanning electron microscopy.And low-field nuclear magnetic resonance(LF-NMR)experiments were conducted to study the water forms at different curing ages.In addition,fluidity,bond strength,and compressive strength measurements were conducted to determine their macroscopic mechanical properties.The obtained results revealed that SA addition improved the viscosity and adhesion of the geopolymer slurry and increased the adhesion strength and density of the geopolymers with low Si/Al ratios.Nevertheless,it also reduced the fluidity of the mixed slurry and shortened the operation time.Adding the optimal amount of SA increased the compressive strength of the MK-based geopolymers.At a SA content of 1.5 wt%,the 7-day strength of the geopolymer reached its maximum value of 28.3 MPa,which was 74.6%higher than that achieved without the addition of SA.Furthermore,the presence of SA changed the water distribution and the pore structure of the MK-based geopolymers,which strongly affected their mechanical properties.展开更多
基金This work was financially supported by the National Key Research and Development Program of China(No.2018YFA0703003)the National Natural Science Foundation of China(No.52125501)+1 种基金the Key Research Project of Shaanxi Province(Nos.2021LLRH-08,2020GXLH-Y-021,and 2021GXLH-Z-028)the Youth InnovationTeam of Shaanxi Universities and the Fundamental Research Funds for the Central Universities.
文摘Bioprinting has been widely investigated for tissue engineering and regenerative medicine applications.However,it is still difficult to reconstruct the complex native cell arrangement due to the limited printing resolution of conventional bioprinting techniques such as extrusion-and inkjet-based printing.Recently,an electrohydrodynamic(EHD)bioprinting strategy was reported for the precise deposition of well-organized cell-laden constructs with microscale filament size,whereas few studies have been devoted to developing bioinks that can be applied for EHD bioprinting and simultaneously support cell spreading.This study describes functionalized alginate-based bioinks for microscale EHD bioprinting using peptide grafting and fibrin incorporation,which leads to high cell viability(>90%)and cell spreading.The printed filaments can be further refined to as small as 30μm by incorporating polyoxyethylene and remained stable over one week when exposed to an aqueous environment.By utilizing the presented alginate-based bioinks,layer-specific cell alignment along the printing struts could be observed inside the EHD-printed microscale filaments,which allows fabricating living constructs with cell-scale filament resolution for guided cellular orientation.
基金the Natural Science Foundation of Shandong Province(No.ZR2022QE153)the Doctoral Startup Fund of Shandong University of Aeronautics(No.2024Y13)。
文摘Metakaolin(MK)and sodium alginate(SA)were employed as raw materials to prepare SA-MK geopolymers,which were inorganic/organic composites.The microscopic morphologies,mineral phases,and chemical bonds of these composites were examined using mercury intrusion porosimetry,X-ray diffraction,Fourier-transform infrared spectroscopy,and scanning electron microscopy.And low-field nuclear magnetic resonance(LF-NMR)experiments were conducted to study the water forms at different curing ages.In addition,fluidity,bond strength,and compressive strength measurements were conducted to determine their macroscopic mechanical properties.The obtained results revealed that SA addition improved the viscosity and adhesion of the geopolymer slurry and increased the adhesion strength and density of the geopolymers with low Si/Al ratios.Nevertheless,it also reduced the fluidity of the mixed slurry and shortened the operation time.Adding the optimal amount of SA increased the compressive strength of the MK-based geopolymers.At a SA content of 1.5 wt%,the 7-day strength of the geopolymer reached its maximum value of 28.3 MPa,which was 74.6%higher than that achieved without the addition of SA.Furthermore,the presence of SA changed the water distribution and the pore structure of the MK-based geopolymers,which strongly affected their mechanical properties.
