Preparation And Biological Evaluation Of Collagen-based Nanocomposite Functional Materials

Collagen,a biocompatible,bioactive and biodegradable natural polymer,is widely used in bone repairing,wound dressing and as drug delivery carrier,etc.Due to the poor mechanical property and high degradation rate of collagen,its application in biological field is limited.Therefore,how to combine collagen with other organic/inorganic materials to prepare collagen-based nanocomposites with acquired characteristics is a hotspot in the current research.In this study,three kinds of collagen-based nanocomposites were prepared by techniques,such as freeze-drying,electrospinning,etc.Firstly,the collagen/graphene(Col/Gr)bone-repairing scaffolds were prepared by combining the freeze-drying and solution blending methods.The results show that the Gr and Col were physical mixing.The addition of Gr decreased the water absorption of the scaffolds but increased its tensile strength.The highest tensile strength(0.69 MPa)is obtained when Gr is added at 1 wt.%.However,the composite scaffolds failed to promote the proliferation of osteoblast compared to the pure Col scaffolds.The more the Gr were added the worse the proliferation of osteoblast.Based on this study,the nano-hydroxyapatite collagen/Poly(lacticco-glycolic acid)/graphene oxide(nHAC/PLGA/GO)bone scaffolds were prepared by freeze-drying technique.The results show that the GO and nHAC/PLGA were physical mixing.The incorporation of GO increased the hydrophilicity,mechanical properties and osteoblast proliferation ability of scaffolds,and the best performance was obtained when the addition amount of GO was 1.5 wt.%.No significant cytotoxicity of nHAC/PLGA/GO scaffolds were observed.The collagen/polyvinyl alcohol/paclitaxel(PTX)-mediated lignin nanoparticles(Col/PVA/LNPs)drug release carrier was prepared by electrospinning and solution blending methods.The results show that the fabricated Col/PVA/LNPs fibers were hydrophilic.The loadding of Col increases the biocompatibility of the fibers.The release rate of PTX decreased by loading Col,while the release rate of PTX increased by adding the LNPs(20 wt.%> 15 wt.%> 10 wt.%> 5 wt.%> 1 wt.%).Therfore,the controllable drug release behavior can be achieved by adjusting the LNPs and Col loading amount.In summary,all the scaffolds are based on Col.To use the scaffolds in orthopedic rehabilitation field,the collagen-based nanocomposites scaffolds for bone repairing and as carrier with drug release function were prepared by combining Col with different organic/inorganic materials mainly using freeze-drying and electrospinning techniques.This preliminary work plays important role for developing environmentally compliant bone repair composite device.