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.


Bone generation on PHBV matrices: an in vitro study
Kose, GT; Korkusuz, F; Korkusuz, P; Purali, N; Ozkul, A; Hasırcı, Vasıf Nejat (2003-12-01)
Bone formation was investigated in vitro by culturing rat marrow stromal osteoblasts in biodegradable, macroporous poly(3-hydroxybutyric acid-co-3-bydroxyvaleric acid) (PHBV) matrices over a period of 60 days. Foams were prepared after solvent evaporation and solute leaching. PHBV solutions with different concentrations were prepared in chloroform: dichloromethane (1:2, v/v). In order to create a matrix with high porosity and uniform pore sizes, sieved sucrose crystals (300-500 mum) were used. PHBV foams we...
Bone tissue engineering on patterned collagen films: an in vitro study
Ber, S; Kose, GT; Hasırcı, Vasıf Nejat (2005-05-01)
This study aimed at guiding osteoblast cells from rat bone marrow on chemically modified and patterned collagen films to study the influence of pattern, on cell guidance. The films were stabilized using different treatment methods including crosslinking with carbodiimide (EDC) and glutaraldehyde, dehydrothermal treatment (DHT), and deposition of calcium phosphate on the collagen membrane.
Bone response to biomimetic implants delivering BMP-2 and VEGF: An immunohistochemical study
RAMAZANOĞLU, Mustafa; Lutz, Rainer; Rusche, Philipp; Trabzon, Levent; Kose, Gamze Torun; Prechtl, Christopher; Schlegel, Karl Andreas (2013-12-01)
This animal study evaluated bone healing around titanium implant surfaces biomimetically coated with bone morphogenic protein-2 (BMP-2) and/or vascular endothelial growth factor (VEGF) by examining bone matrix proteins and mineralisation. Five different implant surfaces were established: acid-etched surface (AE), biomimetic calcium phosphate surface (CAP), BMP-2 loaded CAP surface, VEGF loaded CAP surface and dual BMP-2 + VEGF loaded CAP surface. The implants were inserted into calvariae of adult domestic p...
Fabrication and characterization of bilayered tissue scaffolds incorporating bioactive agents for skin tissue engineering applications
Aktürk, Ömer; Keskin, Dilek; Bilici, Temel; Department of Engineering Sciences (2015)
In this study, it was aimed to fabricate tissue scaffolds from different biological polymers (collagen, silk fibroin and sericin) for skin tissue engineering applications. For this purpose, bilayered scaffolds composed of epidermal (collagen/sericin films) and dermal (collagen sponges, collagen matrices or silk fibroin matrices) layers were produced with different biomaterial fabrication methods. Casting and solvent evaporation (film), lyophilization/freeze-drying (sponge) and dry/wet electro-spinning (micr...
Bone tissue engineering using macroporous PHA-PLA and PHBV scaffolds produced by additive manufacturing and wet spinning
Alagöz, Ayşe Selcen; Hasırcı, Vasıf Nejat; Department of Biology (2016)
Bone supports and protects organs of body, stores minerals, produces blood cells and enables the movement of body. In addition, bone regulates homeostasis by controlling the concentration of key electrolytes in the blood and in the storage of Ca+2 and PO43- ions. Trauma, tumor, nonunion fractures and diseases like osteoporosis lead to bone loss that affects millions of people. Current clinical treatments such as application of autograft and allograft for treatment of these problems are limited due to donor ...
Citation Formats
G. Torun Köse, “Bone tissue generation on biodegradable polymeric scaffolds,” Ph.D. - Doctoral Program, Middle East Technical University, 2002.