Development of Porous Polymer-Ceramic Composites as Bone Grafts
- PDF / 359,074 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 91 Downloads / 431 Views
Development of Porous Polymer-Ceramic Composites as Bone Grafts Samar Kalita, John Finley, Susmita Bose, Howard Hosick1 and Amit Bandyopadhyay School of Mechanical and Materials Engineering 1 School of Molecular Biosciences Washington State University Pullman, WA 99164, USA ABSTRACT Biomaterials have made significant contributions to the advancement of modern health care and drug delivery industries. The present research is based on development of porous polymerceramic composite scaffolds using polypropylene (PP) polymer and tricalcium phosphate (TCP) ceramic for bone-graft applications. Three dimensionally interconnected controlled porosity scaffolds were fabricated using a fused deposition modeling (FDM) system. First, ceramic and polymeric materials were compounded under high shear using a torque rheometer. Compounded materials were then extruded to a 1.78mm diameter continuous filament using a single screw extruder. These filaments were used as a feedstock material for an FDM 1650 machine for direct fabrication of controlled porosity parts. Hg-porosimetry was done to determine pore size and their distribution in these structures. Tensile properties of neat composites and as received polymer were measured and compared using standard dog bone samples. Uniaxial compression tests were performed on cylindrical porous samples having average pore size of 160 µm and 36 vol% porosity. These samples showed an average ultimate compressive strength of 12.7 MPa. Average compressive modulus was calculated as 263 MPa. Cytotoxicity and cell proliferation studies were conducted with OPC1 modified human osteoblast cell-line. It was found that composite matrices were non-toxic and they showed excellent cell growth with OPC1 cells. INTRODUCTION The advent of tissue engineering has motivated scientists and engineers to develop scaffold materials with improved performance for bone and cartilage engineering. The challenges today are not only to mimic the human bone in terms of their functions, but also in terms of structures, properties and biological responses. Among numerous materials available for bone graft applications, ceramics are probably the best because of their low density, chemical inertness, excellent tissue adherence and compositional similarities with natural bone. But ceramics are inherently brittle, which prevent them from being used in load bearing applications, especially in hard tissue engineering. Solution to this problem can be offered by a composite material that tries to incorporate the desirable properties of each of the constituent materials, while mitigating the more limited characteristics of each component. Composites can be either bioinert, bioactive or bioresorbable. Researches on polymer ceramic composites have been focused primarily on two areas: bio-inert polymer with bioactive ceramics [1, 2], and bioactive polymer with bioactive ceramics [3, 4]. Both types have specific advantages for bone graft applications. Human bone is a ceramic polymer composite with interconnected porosity. Bone consists of co
Data Loading...
