COMPOSITE POLYMER-COATED MINERAL SCAFFOLDS FOR BONE REGENERATION: FROM MATERIAL CHARACTERIZATION TO HUMAN STUDIES.

Bovine bone xenografts, made of hydroxyapatite (HA), were coated with poly(L-lactide-co-ε- caprolactone) (PLCL) and RGD-containing collagen fragments in order to increase mechanical properties, hydrophilicity, cell adhesion and osteogenicity. In vitro the scaffold microstructure was investigated with Environmental Scanning Electronic Microscopy (ESEM) analysis and micro tomography, while mechanical properties were investigated by means compression tests. In addition, cell attachment and growth within the three-dimensional scaffold inner structure were validated using human osteosarcoma cell lines (SAOS-2 and MG-63). Standard ISO in vivo biocompatibility studies were carried out on model animals, while bone regenerations in humans were performed to assess the efficacy of the product. All results from in vitro to in vivo investigations are here reported, underlining that this scaffold promotes bone regeneration and has good clinical outcome.

Porous biodegradable microtubes-based scaffolds for tissue engineering, part I: production and preliminary in vitro evaluation.

UNLABELLED: PURPOSE: we aimed at investigating spinning as a potential technology to produce porous microtubes for constructing scaffolds. Spinning is indeed a well known technique for producing polymeric fibres, also used in the biomedical field, but its applications for tissue engineering purposes has never been deeply investigated. METHOD: the behaviour of a multi-phase poly-lactide-caprolactone copolymer based solution was here studied for the production under spinning condition of porous microtubes for patterning planar and three dimensional bioactive systems to be used for tissue regeneration. Obtained non-woven fabrics were tested investigating cells response with fibroblast, osteoblasts and chondrocytes. RESULTS: once achieved optimal process parameters, microtubes were produced with a controlled and well diffused porosity which were then used to build two and three dimensional scaffolds. Cytocompatibility tests performed on these scaffolds showed good results on all tested cell models, both qualitatively (SEM imaging) and quantitatively. Particularly, cell proliferation assays by Alamar Blue staining indicated increasing trends with time and comparable values with controls. CONCLUSIONS: results hereby described represent a proof of concept of the process developed and its applicability for obtaining microtubes with controlled porosity. Moreover, two and three dimensional scaffolds built from such fibres showed to be very promising substrates for cell adhesion and growth. Finally, the process developed can be taken into GMP qualification and thus scaffolds can be upgraded to medical devices and used for regenerative medicine into human applications.