Starch-poly(epsilon-caprolactone) and starch-poly(lactic acid) fibre-mesh scaffolds for bone tissue engineering applications : structure, mechanical properties and degradation behaviour

摘要

In scaffold-based tissue engineering strategies, the successful regeneration of tissues from matrixproducingconnective tissue cells or anchorage-dependent cells (e.g. osteoblasts) relies on the useof a suitable scaffold. This study describes the development and characterization of SPCL (starchwith !-polycaprolactone, 30 : 70%) and SPLA [starch with poly(lactic acid), 30 : 70%] fibre-meshes,aimed at application in bone tissue-engineering strategies. Scaffolds based on SPCL and SPLAwere prepared from fibres obtained by melt-spinning by a fibre-bonding process. The porosity ofthe scaffolds was characterized by microcomputerized tomography (μCT) and scanning electronmicroscopy (SEM). Scaffold degradation behaviour was assessed in solutions containing hydrolyticenzymes ("-amylase and lipase) in physiological concentrations, in order to simulate in vivoconditions. Mechanical properties were also evaluated in compression tests. The results showthat these scaffolds exhibit adequate porosity and mechanical properties to support cell adhesionand proliferation and also tissue ingrowth upon implantation of the construct. The results ofthe degradation studies showed that these starch-based scaffolds are susceptible to enzymaticdegradation, as detected by increased weight loss (within 2 weeks, weight loss in the SPCL samplesreached 20%). With increasing degradation time, the diameter of the SPCL and SPLA fibresdecreases significantly, increasing the porosity and consequently the available space for cells andtissue ingrowth during implantation time. These results, in combination with previous cell culturestudies showing the ability of these scaffolds to induce cell adhesion and proliferation, clearlydemonstrate the potential of these scaffolds to be used in tissue engineering strategies to regeneratebone tissue defects.