INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Hydrolytic stability, thermal and swelling behavior of highly porous and non-porous biomedical polyurethanes
Autor/es:
P.C. CARACCIOLO; F. BUFFA; V. THOMAS; G.A. ABRAHAM
Lugar:
La Habana, Cuba
Reunión:
Congreso; V Congreso Internacional de Biomateriales (BIOMAT 2010); 2010
Institución organizadora:
Cátedra UNESCO de Biomateriales
Resumen:
The development of elastomeric biodegradable and biocompatible segmented polyurethanes (SPU) for use in tissue engineering applications has been a subject of considerable interest in recent years. In this work, a series of poly(e-caprolactone)-based SPU with different hard segment chemistry were synthesised using 1,6-hexamethylene diisocianate (HDI) and novel chain extenders containing urea groups or an aromatic aminoacid derivative. Non-porous films were prepared by casting of SPU solutions in N,N-dimethylacetamide onto siliconised Petri dishes. Micro/nanofibrous scaffolds were obtained by electrospinning technique. SPU solutions were prepared in 1,1,1,3,3,3-hexafluoro-2-propanol (20% w/v) and delivered at a 0.5-3 ml/h flow rate. Electrospinning was carried out by applying a positive voltage of 15 kV. Electrospun fibers were deposited on a grounded flat aluminum plate, with a needle-plate distance of 15 cm. Thermal properties were determined by differential scanning calorimetry (DSC). Swelling and in vitro hydrolytic behaviors were both tested in phosphate-buffered solution (PBS) at 37ºC for specific periods of time. The effect of the hard segment composition and processing technique (non-porous film and non-woven mesh) on the measured properties were analysed. Thermal transitions were affected by the processing conditions. Film samples displayed low swelling (less than 2 wt%), the values being much higher for the scaffolds. The introduction of a chain extender with hydrolysable ester bonds contributed to a higher degradation rate. The fibrous scaffolds also exhibited higher hydrolytic stability due to their more crystalline structures and higher degrees of association by hydrogen bonding.