تهيه و ارزيابي داربست كامپوزيتي PLGA/nano-BCP براي مهندسي بافت استخوان

چكيده انگليسي :

Preparation and Evaluation of PLGA nano BCP Composite Scaffolds for Bone Tissue Engineering Mehdi Ebrahimian Hosseinabadi mebrahimian@ma iut ac ir October 30 2011 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Isfahan University of Medical Sciences Isfahan 81746 73461 Iran1st Supervisor Fakhredin Ashrafizadeh 1 ashrafif@cc iut ac ir2nd Supervisor Mohammadreza Etemadifar m etemadifar@med mui ac irAdvisor Mohammad Hossein Fathi Department Graduate Coordinator Masoud Panjepour AbstractThe aim of this research was preparation and evaluation of poly lactide co glaycolide nano biphasic calciumphosphate PLGA nBCP composite scaffolds for bone tissue engineering The nBCP with composition ofHA 7 TCP 60 40 was produced by heating of bovine bone at 700 C Composite scaffolds were made by usingPLGA matrix and 10 50 wt nBCP powders as the reinforcement material All scaffolds were fabricated bythermally induced phase separation TIPS and their properties were compared for use in bone tissueengineering The freeze dryer was applied to fabricate scaffolds at a temperature of 60 C and pressure of 0 04mbar The scaffolds had more than 89 porosity with an average pore size of 60 to 150 m The mechanicaland in vitro degradation properties of PLGA and PLGA nBCP scaffolds were evaluated and their cell behaviorwas investigated under cell culture tests The results of tensile tests showed that the yield strength of thePLGA nBCP composite scaffold with 30 wt nBCP particles was about 0 54 MPa which was higher than othersamples By addition of 30 wt nBCP to PLGA matrix a more uniform distribution of particles and lessagglomeration was observed in comparison to composite scaffolds containing 40 and 50 wt particles Withincreasing the amount of particles in the scaffold the elastic modulus of scaffolds were increased so that theelastic modulus of PLGA 50 wt nBCP 14 83 0 83 MPa was about 8 7 times higher than the base PLGAscaffold The nBCP reinforcement particles in the composite scaffolds due to their high surface energy andstrong bonds with the polymer matrix can increase the modulus of elasticity and yield strength of the resultantcomposite Degradation tests showed that the weight loss of the PLGA nBCP composite scaffolds were morethan that of PLGA scaffolds and by increasing the amount of nBCP particles in the composite scaffolds the rateof weight loss increased The weight loss affected the mechanical properties of scaffolds significantly in such away that after immersion in PBS solution for 8 weeks the yield strength and elastic modulus dropped tonegligible values and the scaffolds were ruptured easily Also MTS assay for MG 63 osteoblast cells in contactwith PLGA and PLGA nBCP composite scaffolds with 30 40 and 50 wt nBCP particles showed that cellviability and proliferation for composite scaffolds were more than pure polymer scaffolds Addition of nBCPreinforcement particles in the range of 30 to 50 wt significantly enhanced the cell behavior of compositescaffolds and can provide a suitable condition for the repair of injured bone tissue In conclusion it can be statedthat the PLGA nBCP scaffolds with 30 wt nBCP have better mechanical and degradation properties and cellbehavior than other scaffolds Keywords Biphasic calcium phosphate Poly lactic co glycolic acid Nano composite s Scaffold s Hydroxyapatite Bioactivity degradation Bone tissue engineering Professor Department of Materials Engineering Isfahan University of Technology Isfahan Iran Assistant Professor School of Medicine Isfahan University of Medical Sciences Isfahan Iran Assistant Professor Department of Materials Engineering Isfahan University of Technology Isfahan Iran 1

ابراهيميان، مهدي

تهيه و ارزيابي داربست كامپوزيتي PLGA/nano-BCP براي مهندسي بافت استخوان

فسفات كلسيم دو فازي , پلي لاكتيك-كو-گلايكوليك اسيد , داربست , هيدروكسي آپاتيت , زيست فعالي , تخريب پذيري