Bone tissue generation on biodegradable polymeric scaffolds

Torun Köse, Gamze
In the present study, tissue engineered bone was produced on calcium phosphate loaded collagen and PHBV8 matrices. Osteoblasts isolated from rat bone marrow were characterized by light microscopy, alkaline phosphatase (ALP) activity, osteocalcin determination assay, and Western blots for integrin. Population doubling time of the cells was found as 50 ± 2 h at 37 °C in a CO2 incubator. PHBV8 foams iiiwere treated with rf-oxygen plasma to modify their surface chemistry and hydrophilicity to increase the reattachment of osteoblasts. Optimum power and duration was found to be 100 W 10 min. Another carrier material, lyophilized collagen foam, was loaded with calcium phosphate to mimic the composition of the bone to provide a better environment for cell proliferation and also to prevent rapid resorption of the foam. The presence of calcium phosphate and the molar ratio of calcium over phosphorus (2.26) in the collagen matrix was determined by SEM- EDS. The surface characteristics, average pore size and distribution in PHBV8 and collagen matrices were studied by SEM and Scion Image Analysis Program. Void volume and density of the foams were also found to be related to foam preparation conditions. Stability of PHBV foams in aqueous media was studied. The weight and density were unchanged for a period of 120 days but then a significant decrease was observed for the rest of the study. In order to determine the cell density of the films and the foams, MTS assay was carried out. Osteoblast growth inside the matrices was also determined by ALP and osteocalcin assays, Western blot for integrin, along with histological examinations, SEM and confocal microscopy. After 29 days of incubation, growth of osteoblasts on matrices and initiation of mineralization were observed. Large size sucrose (300-500 urn) loaded PHBV8 (6 %, w/w) foams treated with 100 W 10 min rf-plasma were found to be the most suitable matrices for osteoblast growth.
Citation Formats
G. Torun Köse, “Bone tissue generation on biodegradable polymeric scaffolds,” Ph.D. - Doctoral Program, Middle East Technical University, 2002.