Development of polyurethane scaffolds for soft tissue-engineering applications

P.C. CARACCIOLO; F. BUFFA; G.A. ABRAHAM

Rosario, Santa Fe

Taller; 1º Taller de Órganos Artificiales, Biomateriales e Ingeniería de Tejidos (BIOOMAT); 2009

Centro Binacional (Argentina – Italia) de Criobiología Clínica y Aplicada (CAIC), Facultad de Ciencias Bioquímicas y Farmacéuticas de la Universidad Nacional de Rosario, y Sociedad Latinoamericana de Biomateriales (SLABO)

The development of biomimetic highly-porous scaffolds is essential for successful tissue engineering. Segmented poly(ester urethane)s and poly(ester urethane urea)s have been infrequently used for the fabrication of electrospun nanofibrous tissues, which is surprising because these polymers represent a very large variety of materials with tailored properties. This study reports the preparation of new electrospun elastomeric polyurethane scaffolds. Two novel biodegradable segmented polyurethanes, synthesized from poly(e-caprolactone) diol, 1,6-hexamethylene diisocyanate, and diester-diphenol or diurea-diol chain extenders, were used. The electrospinnability and the morphology of the electrospun SPU scaffolds were investigated and discussed. The electrospinning parameters such as solution properties (polymer concentration and solvent) and processing parameters (applied electric field, needle to collector distance and solution flow rate) were optimized to achieve smooth, uniform bead-free fibers mimicking the protein fibers of native extracellular matrix. The poly(ester urethane urea) was not possible to electrospin into uniform matrices employing N,N-dimethylacetamide (DMAc), and DMAc/acetone and N,N-dimethylformamide (DMF)/tetrahydrofuran (THF) solvent mixtures, whereas electrospun scaffolds from HPF solutions resulted in uniform bead-free-fiber matrices with a diameter average of 1.22 ± 0.42 mm. On the other side, the poly(ester urethane) could be processed from DMF/THF solutions, achieving fibers with a diameter average of 1.31 ± 0.82 mm, while electrospinning from 1,1,1,3,3,3-hexafluoro-2-propanol (HFP) solutions resulted in matrices with a narrower diameter distribution (1.39 ± 0.56 mm). Thus, HFP is a better solvent than DMF/THF and DMAc/acetone solvent mixtures for electrospinning the present polyurethanes. The obtained elastomeric polyurethane scaffolds could be appropriate for soft tissue-engineering applications.