The Study On Biodegradation Of PCL & Its Scaffold Fabrication Methods

The objective in research of tissue engineering is to permanently repair or reconstruct the deformities in tissue and organs both from structures and properties. As the precursor in research, biodegradable scaffolds should meet multi-functional requests including biocompatibilities, microstructures and 3D shapes.In this paper, we studied the biodegradability of PCL which was selected as scaffold material. Combined with self-made moulds, auricular shape scaffolds were fabricated by two methods—improved solvent casting/particulate leaching (SC/PL) and fiber bonding. The effects of high temperature and enzyme on degradation, and the fabrication processes on microstructures were discussed in detail.The results indicated that PCL degraded slowly in a bulk degradation manner. According with its two stage mechanism, PCL showed little weight loss after 12 weeks, but molecular weight kept falling. Amorphous region hold priority where degradation occurred. The degradation velocity would be impacted by shapes and initial molecular weights of materials, as well as the lipase and 70℃conditions which showed acceleration. Holding good compatibility, PCL was appropriate for long period implant, which might overcome the problems of inflammation or mismatch in tissue regeneration.Scaffolds fabricated via SC/PL associated with bonding process of porogen particles, could be applied in tissue engineering of cartilage with porosity higher than 90% and pore size ranging between 10-80μm. The interconnection and porosity of scaffolds should be improved if centrifugation treating was applied in bonding process, as well as applying vacuum under high temperature during deprivation of solvents. Scaffolds obtained from fiber bonding method could reach porosity of 70% and pore size between 70-300μm. The strength of PCL fiber spun in proper condition could reach 5cN/dtex, which supplied scaffolds with sufficient mechanical property. Both thermostatic water bath and oven were suitable heaters. Proper fiber dimensions provided scaffolds with high porosities and narrow distribution of pore size. Scaffolds fabricated from two methods hold good hydrophilia, which was favorable for cell adhesion and generation. High porosity was an advantage for better hydrophilia.PCL owning excellent biological and physical properties should be an attracting prospect as scaffold biomaterial. For scaffold fabrication, improving of traditional methods and new attempted melt bonding process both were feasible to obtain high performance in microstructures which were controllable for different applications.