Electrospinning of Bioactive Collagen Fibers

Guided bone reformation is one of the present challenges in orthopedic and dental surgery. Implants need to be osteoinductive and it would be advantageous to have an implant material presenting a chemical composition and a structure as close as possible to bone tissue. Collagen has a large range of biomedical appliances due to its antigenicity and fiber forming ability. Furthermore, collagen can be used as carrier of bioactive components such as calcium phosphates. The latter are widely used as biocompatible and osteoconductive materials. The problems in bone regeneration deriving from scar tissue formation might be avoided by an anisotropic bilayer used as bone wrapping material with its osteoinductive side on the defect and its non-osteoinductive side presenting a barrier for cells other than osteoblasts. Such a bifunctional double membrane was developed using amorphous calcium phosphate (ACP) nanoparticles synthesized by flame spray synthesis that were combined with collagen (Col) and poly(lactide-co-glycolide) (PLGA) via electrospinning (Fig. 1a). To obtain the double membrane, pure PLGA (Fig. 1b) was electrospun as described by Schneider et al. [1]. On top of the pure polymer layer ACP/Col/PLGA fibers dyed with Brilliant Blue were electrospun. Fibers were stable enough to undergo crosslinking and in vitro biomineralization experiments. The bilayer was investigated in a cell culture study with human mesenchymal stem cells [2]. References: [1] O.D. Schneider, S. Loher, T.J. Brunner, L. Uebersax, M. Simonet, R.N. Grass, H.P. Merkle, W.J. Stark, J. Biomed. Mater. Res., Part B, 2008, 84B(2) 350. [2] N. Hild, O.D. Schneider, N.A. Luechinger, F.M. Koehler, D. Mohn, B.W. Thimm, S. Hofmann, R. Müller, W.J. Stark, in preparation.