Viscous aqueous solutions of chitosan and polyvinyl alcohol (PVA) were blended to enhance miscibility and avoid polymer phase separation. The mixtures were drop-casted and air dried to yield composite film materials t...Viscous aqueous solutions of chitosan and polyvinyl alcohol (PVA) were blended to enhance miscibility and avoid polymer phase separation. The mixtures were drop-casted and air dried to yield composite film materials that were characterized by equilibrium water uptake, physical stability in aqueous solution, and thermal stability. Chitosan/PVA blends have greater thermal stability, unique morphology, and reduced solubility in acidic solution, thus extending the useful pH range for chitosan as a sorbent material. The uptake properties of the films was investigated using methylene blue (MB) and a p-nitrophenol (PNP) dyes, where it was found that each single component polymer has greater uptake toward MB than PNP. A direct relationship between film composition (chitosan:PVA) with solution pH and the uptake of MB was observed. The results are in agreement with electrostatic interactions and contributions due to the hydrophobic effect for such composite materials.展开更多
Three-dimensional printing technologies exhibit tremendous potential in the advancing fields of tissue engineering and regenerative medicine due to the precise spatial control over depositing the biomaterial.Despite t...Three-dimensional printing technologies exhibit tremendous potential in the advancing fields of tissue engineering and regenerative medicine due to the precise spatial control over depositing the biomaterial.Despite their widespread utilization and numerous advantages,the development of suitable novel biomaterials for extrusion-based 3D printing of scaffolds that support cell attachment,proliferation,and vascularization remains a challenge.Multi-material composite hydrogels present incredible potential in this field.Thus,in this work,a multi-material composite hydrogel with a promising formulation of chitosan/gelatin functionalized with egg white was developed,which provides good printability and shape fidelity.In addition,a series of comparative analyses of different crosslinking agents and processes based on tripolyphosphate(TPP),genipin(GP),and glutaraldehyde(GTA)were investigated and compared to select the ideal crosslinking strategy to enhance the physicochemical and biological properties of the fabricated scaffolds.All of the results indicate that the composite hydrogel and the resulting scaffolds utilizing TPP crosslinking have great potential in tissue engineering,especially for supporting neo-vessel growth into the scaffold and promoting angiogenesis within engineered tissues.展开更多
Cellulose nanocrystals isolated from water hyacinth fiber(WHF)have been studied as a reinforcement for polyvinyl alcohol(PVA)-gelatin nanocomposite.Central composite design was used to study and optimize effects of th...Cellulose nanocrystals isolated from water hyacinth fiber(WHF)have been studied as a reinforcement for polyvinyl alcohol(PVA)-gelatin nanocomposite.Central composite design was used to study and optimize effects of the PVA,gelatin and cellulose nanocrystal(CNC)concentration on tensile strength and elongation of formed films.The results of this study showed that WHF CNC had a diameter range of 20-50 nm produced films reaching 13.8 MPa tensile strength.Thermal stability of the films was improved from 380℃ to 385℃ in addition of CNCs and maximum storage modulus of 3 GPa were observed when 5 wt%CNC was incorporated.However,water absorption,water vapour permeability(WVP)and moisture uptake of the films decreased in addition of CNC to the PVA-gelatin blends.Moisture uptake decreased from 22.50%to 19.05%while the least WVP when 10 wt%CNC added was 1.64×10^(-6)g/(m·h·Pa).These results show possibility for industrial application of WHF CNC and PVA-gelatin blends in biodegradable films for on-the-go food wrappers.展开更多
文摘Viscous aqueous solutions of chitosan and polyvinyl alcohol (PVA) were blended to enhance miscibility and avoid polymer phase separation. The mixtures were drop-casted and air dried to yield composite film materials that were characterized by equilibrium water uptake, physical stability in aqueous solution, and thermal stability. Chitosan/PVA blends have greater thermal stability, unique morphology, and reduced solubility in acidic solution, thus extending the useful pH range for chitosan as a sorbent material. The uptake properties of the films was investigated using methylene blue (MB) and a p-nitrophenol (PNP) dyes, where it was found that each single component polymer has greater uptake toward MB than PNP. A direct relationship between film composition (chitosan:PVA) with solution pH and the uptake of MB was observed. The results are in agreement with electrostatic interactions and contributions due to the hydrophobic effect for such composite materials.
基金The authors acknowledge the funding support from the National Natural Science Foundation of China(Nos.52175474 and 51775324)the China Scholarship Council(No.202006890054).
文摘Three-dimensional printing technologies exhibit tremendous potential in the advancing fields of tissue engineering and regenerative medicine due to the precise spatial control over depositing the biomaterial.Despite their widespread utilization and numerous advantages,the development of suitable novel biomaterials for extrusion-based 3D printing of scaffolds that support cell attachment,proliferation,and vascularization remains a challenge.Multi-material composite hydrogels present incredible potential in this field.Thus,in this work,a multi-material composite hydrogel with a promising formulation of chitosan/gelatin functionalized with egg white was developed,which provides good printability and shape fidelity.In addition,a series of comparative analyses of different crosslinking agents and processes based on tripolyphosphate(TPP),genipin(GP),and glutaraldehyde(GTA)were investigated and compared to select the ideal crosslinking strategy to enhance the physicochemical and biological properties of the fabricated scaffolds.All of the results indicate that the composite hydrogel and the resulting scaffolds utilizing TPP crosslinking have great potential in tissue engineering,especially for supporting neo-vessel growth into the scaffold and promoting angiogenesis within engineered tissues.
基金This work was supported by the National Natural Science Foundation of China(Grants No.20075006,29975006,20375012)the Foundation for Ph.D.Thesis Research(No.20010532008)the Foundation of Science Commission of Yunnan Province(No.2002B0033M).
文摘Cellulose nanocrystals isolated from water hyacinth fiber(WHF)have been studied as a reinforcement for polyvinyl alcohol(PVA)-gelatin nanocomposite.Central composite design was used to study and optimize effects of the PVA,gelatin and cellulose nanocrystal(CNC)concentration on tensile strength and elongation of formed films.The results of this study showed that WHF CNC had a diameter range of 20-50 nm produced films reaching 13.8 MPa tensile strength.Thermal stability of the films was improved from 380℃ to 385℃ in addition of CNCs and maximum storage modulus of 3 GPa were observed when 5 wt%CNC was incorporated.However,water absorption,water vapour permeability(WVP)and moisture uptake of the films decreased in addition of CNC to the PVA-gelatin blends.Moisture uptake decreased from 22.50%to 19.05%while the least WVP when 10 wt%CNC added was 1.64×10^(-6)g/(m·h·Pa).These results show possibility for industrial application of WHF CNC and PVA-gelatin blends in biodegradable films for on-the-go food wrappers.
