Preparation and characterization of biodegradable composite systems as hard tissue supports: bone fillers, bone regeneration membranes and scaffolds

Download

index.pdf

Date

2012

Author

Sezer, Ümran Aydemir

Metadata

Show full item record

Item Usage Stats

259
views

91
downloads

In tissue engineering applications, use of biodegradable and biocompatible materials are essential. As the tissue regenerate itself on the material surface, the material degrades with enzymatic or hydrolytic reactions. After a certain time, natural tissue takes the place of the artificial support. Poly(ε-caprolactone) (PCL) is one of the preferable polymers used in the restoration of the bone defects due to its desirable mechanical properties and biocompatibility. Addition of inorganic calcium phosphate particles in PCL structures can improve the mechanical properties as well as osteoconductivity; and presence of an antibiotic can prevent infection that may occur at the defect site. In this study, three forms of biodegradable hard tissue supports which are bone fillers, bone regenerative membranes and 3D scaffolds were designed and prepared. As biodegradable bone fillers, composite microspheres containing gelatin and β-tricalcium phosphate (β-TCP) were prepared and characterized. Synthesized β-TCP particles were coated with gelatin at different weight ratios and the effects of β-TCP/Gelatin ratio on the morphology of the microspheres were evaluated. Also, a model antibiotic, gentamicin, was loaded to these microspheres and release behaviours of the drug and its antibacterial effect on E.Coli was determined. The selected composition of these microspherical bone fillers were used as additives in the preparation of bone regenerative membranes and scaffolds. For this purpose, microspheres were added into PCL solution and processed by either solvent casting or freeze-drying in order to prepare bone regenerative membranes or scaffolds, respectively. For every material, the ratio of constituents (microsphere and PCL) was altered in order to obtain optimum properties in the resulted hard tissue support structure. The effects of the ratio of the microspheres to PCL in terms of morphological, mechanical and degradation properties of composite films, as well as in vitro antibiotic release and antibacterial activities against E.Coli and S.Aureus were investigated. For scaffolds, the effects of the ratio of the microspheres to PCL on the morphological, mechanical, pore size distribution, degradation properties and in vitro antibiotic release were examined.

Subject Keywords

Biotechnology.

URI

http://etd.lib.metu.edu.tr/upload/12614191/index.pdf
https://hdl.handle.net/11511/21332

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Production and properties of glass bonded apatite-wollastonite bioceramics Vakıfahmetoğlu, Çekdar; Timuçin, Muharrem; Department of Metallurgical and Materials Engineering (2005) Apatite containing bioceramic materials are considered to be potentially useful for replacement or repair of natural bone. In the present study, the aim was to produce a new composite bioceramic containing crystalline apatite and wollastonite phases with a bimodal grain size distribution. The manufacturing scheme was based on the liquid phase sintering process in which the compacts pressed from powders of apatite (HAP or Si-HAP) and pseudowollastonite was sintered in the presence of a liquid phase. Three di...
Production of recombinant proteins by yeast cells Celik, Eda; Çalık, Pınar (Elsevier BV, 2012-09-01) Yeasts are widely used in production of recombinant proteins of medical or industrial interest. For each individual product, the most suitable expression system has to be identified and optimized, both on the genetic and fermentative level, by taking into account the properties of the product, the organism and the expression cassette. There is a wide range of important yeast expression hosts including the species Saccharomyces cerevisiae, Pichia pastoris, Hansenula polymorpha, Kluyveromyces lactis, Schizosa...
Isolation of antimicrobial molecules from agricultural biomass and utilization in xylan-based biodegradable films Çekmez, Umut; Bakır, Ufuk; Department of Biotechnology (2010) Cotton stalk lignin extractions were performed via alkaline methods at different conditions. Crude and post treated cotton stalk lignins, olive mill wastewater and garlic stalk juice were examined in terms of antimicrobial activity. Antimicrobial lignin was isolated depending on alkaline extraction conditions. Lignin extracted at 60°C exhibited significant antimicrobial effect towards both Escherichia coli and Bacillus pumilus. However different post treatments such as ultrasonication and TiO2-assisted phot...
Design of intelligent nanoparticles for use in controlled release Bayyurt, Banu; Hasırcı, Vasıf Nejat; Department of Biotechnology (2009) The aim of this project was to design an intelligent controlled release system based on thermoresponsive nanoparticles for cancer therapy and to evaluate the efficiencies of these systems with in vitro cell culture. Poly(Nisopropylacrylamide), an important thermoresponsive polymer, was selected for this study to prepare the responsive nanoparticles. This polymer has an lower critical solution temperature (LCST) of 32 oC, below which it is hydrophilic and above this temperature, it shows hydrophobic behavior...
Partial removal of proteins from lactic acid fermentation broth and recovery of proteins from brewery wastes by foam fractionation technique Kurt, Lütfiye; Hamamcı, Haluk; Department of Food Engineering (2006) Foam separation is a simple and economic method for separation of surface-active molecules such as proteins and enzymes from aqueous solutions. In this study, lactic acid broth, spent brewer’s yeast extract and residual beer was used to investigate the applicability and efficiency of foam separation technique in partial purification of fermentation products and recovery of valuable components from industrial waste streams. The effects of the process variables initial feed concentration, air flow rate, foami...

Citation Formats

Ü. A. Sezer, “Preparation and characterization of biodegradable composite systems as hard tissue supports: bone fillers, bone regeneration membranes and scaffolds,” M.S. - Master of Science, Middle East Technical University, 2012.