8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Fri 911:10-14:00P4.35Gamma-ray cross-linked collagen gels as properscaffolds for obtaining collagen-hydroxyapatitecompositesMarin Micutz, 1 Teodora Staicu, 1 Corneliu Ghica, 2 and Viorel Circu 11 University of Bucharest, 4-12 Regina Elisabeta Blvd. , 030018, Bucharest,Romania2 National Institute of Materials Physics, Magurele-Bucharest, RomaniaCollagens, as a proteins family characterized by a broad heterogeneity, are the most abundant proteinsin the animal kingdom and the human body. Among these, the collagen type I (CI) is byfar the preponderant member, being mainly located into the extracellular matrix. CI, almost irrespectiveof the cells tissue, due to its low antigenicity, good bioresorbability and easy recognitionby the cells that interact with, is widely used to realize a lot of systems (scaffolds, membranes,composites, wires, gels, etc. ) that are successfully applied in medicine, pharmacy or cosmetics.This study reports on aspects related to the native structure of CI (molecular integrity, supramolecularassembly in solution, denaturation temperature) and viscoelasticity behavior of the aqueoussolutions/suspensions and gels (resulted by γ-ray cross-linking) precursory of the final system intendedto be obtained: collagen-hydroxyapatite composite (CH) for hard tissue repair. CI wasextracted from calf-skin and successively purified by repeated salting out-redissolution cycles, followedeventually by an exhaustive dialysis against aqueous solution of acetic acid 0.1M. In orderto release the telopeptides of the CI molecule, pepsin was used in the extraction stage. The useof γ-ray as a physical cross-linker was chosen in order to avoid using chemical cross-linkers (glutaraldehydeor carbodiimides) which are pretty cytotoxic. At the same time, CHs obtained startingfrom collagen gels, via 60 Co γ-irradiation, at different doses, were characterized by porositymeasurements, thermal, morphological and elemental analysis.35