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J Mater Sci: Mater Med (2009) 20:17291741 DOI 10.1007/s10856-009-3722-4
Microporous biodegradable polyurethane membranes for tissue engineering
Yuen Kee Tsui Sylwester Gogolewski
Received: 4 October 2008 / Accepted: 23 February 2009 / Published online: 20 March 2009 Springer Science+Business Media, LLC 2009
Abstract Microporous membranes with controlled pore size and structure were produced from biodegradable polyurethane based on aliphatic diisocyanate, poly(e-caprolactone) diol and isosorbide chain extender using the modied phase-inversion technique. The following parameters affecting the process of membrane formation were investigated: the type of solvent, solventnonsolvent ratio, polymer concentration in solution, polymer solidication time, and the thickness of the polymer solution layer cast on a substrate. The experimental systems evaluated were polymerN,N-dimethylformamidewater, polymer N,N-dimethylacetamidewater and polymerdimethylsulf-oxidewater. From all three systems evaluated the best results were obtained for the system polymerN,N-dimethylformamidewater. The optimal conditions for the preparation of microporous polyurethane membranes were: polymer concentration in solution 5% (w/v), the amount of nonsolvent 10% (v/v), the cast temperature 23C, and polymer solidication time in the range of 2448 h
depending on the thickness of the cast polymer solution layer. Membranes obtained under these conditions had interconnected pores, well dened pore size and structure, good water permeability and satisfactory mechanical properties to allow for suturing. Potential applications of these membranes are skin wound cover and, in combination with autogenous chondrocytes, as an articial periosteum in the treatment of articular cartilage defects.
1 Introduction
Interest in biodegradable polyurethanes for implantable devices goes back to the early 1980s [112]. Continuing efforts to replace defective tissues and organs using tissue engineering approaches [13] have been the reason that interest in biodegradable polyurethanes has gained new momentum [1436]. The numerous possible applications for biodegradable polyurethanes in tissue engineering include use as three-dimensional porous scaffolds for cancellous bone graft substitutes and microporous membranes for the treatment of articular cartilage defects in procedures where cultured autogenous chondrocytes are applied in combination with an autogenous periosteal ap [37, 38]. As harvesting a periosteal ap creates new wounds, the use of an articial ap might not only avoided this problem but also simplify the surgical procedure. In addition such aps could be seeded with autogenous chondrocytes to facilitate defect healing. Microporous membranes from elastomeric biodegradable polyurethanes are among the candidates for such articial periosteal aps.
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