Biodegradable and elastic flock scaffolds from a single material system based on chitosan for articular cartilage regeneration

点击翻译按钮获取中文摘要

The aim of this project is the development of a biodegradable and mechanically stable elastic flock scaffold from a single material system with adjustable parameters based on chitosan as well as the systematic cell biological investigation in regard to its application as three-dimensional carrier structure for tissue engineering of articular cartilage. For this a reproducible spin process for depiction of filament yarns from pure chitosan with defined biological function and properties suitable for textile processing will be developed. Both a chitosan membrane and a novel ultra light surface structured chitosan woven fabric will be developed as substrate (carrier material). A novel adhesive based on chitosan, is applied to join the flock fibers with the substrate. In order to guarantee the electrical conductivity of novel chitosan flock fibers for electrostatic flocking, biocompatible recipe for preparation will be synthesized. A completely biodegradable flock scaffold, which is available as a single material system based on chitosan as substrate, flock fiber and adhesive, is generated by targeted configuration of each component of the flock process. The high demands concerning medical application of the scaffolds require a closed process chain. This will lead to a defined, scalable pore size (preferably 110-150 µm) and simultaneously to a high dimension stability of the scaffolds by minimum material requisition. The anisotropic morphology of the constructs guarantees both mechanical strength, elasticity and a high porosity at the same time.The biocompatibility of all components is proved by cell culture investigations. A continuous and qualified evaluation of the actual work state and a specification of requirements concerning the materials and structures as a fundament for targeted technology and structure development is carried out by means of in vitro tests. Also stability of the flock scaffolds under cell culture conditions and their degradation behavior will e studied. Seeding of biodegradable flock scaffolds with human primary chondrocytes (hCh) and human mesenchymal stem cells (hMSC) and analysis of their chondrogenic differentiation demonstrate the effects of anisotropic pore morphology on the cell behavior. An effective method of cell seeding of these open porous scaffolds will be developed by generating suited biopolymer gels for cultivation of hCh/hMSC on biodegradable flock scaffolds. In additional experiments the effect of cyclic mechanical loading on matrix synthesis and chondrogenic differentiation of cells cultivated in flock scaffolds will be investigated, which will provide the basis for a novel therapy of articular cartilage defects.