title: Novel tubular composite matrix for bone repair.
abstract: Tissue engineering develops organ replacements to overcome the limitations associated with autografts and allografts. The work presented here details the development of biodegradable, porous, three-dimensional polymer-ceramic-sintered microsphere matrices to support bone regeneration. Poly(lactide-co-glycolide)/hydroxyapatite microspheres were formed using solvent evaporation technique. Individual microspheres were placed in a cylindrical mold and sintered at various temperatures. Scaffolds were characterized using scanning electron microscopy, mercury porosimetry, and mechanical testing in compression. After varying the temperature of sintering, a single temperature was selected and the time of sintering was varied. Mechanical testing indicated that as the sintering temperature or time was increased, the elastic modulus, compressive strength, maximum compressive load, and energy at failure significantly increased. Furthermore, increasing the sintering temperature or time resulted in a decreased porosity and the spherical morphology of the microspheres was lost as the microspheres blended together. To more closely mimic the bone marrow cavity observed in native bone tissue, tubular composite-sintered microsphere matrices were formed. These scaffolds demonstrated no statistically significant difference in compressive mechanical properties when compared with cylindrical composite-sintered microsphere matrices of the same dimension. One potential application for these scaffolds is bone regeneration.
authors.affiliation: Department of Biomedical Engineering, University of Virginia, PO Box 800759, Charlottesville, Virginia 22908, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Kofron
authors.forename: J A
authors.initials: JA
authors.lastname: Cooper
authors.forename: S G
authors.initials: SG
authors.lastname: Kumbar
authors.forename: C T
authors.initials: CT
authors.lastname: Laurencin
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D001861:Bone Regeneration; D018786:Bone Substitutes / Q000302:isolation & purification; D002448:Cell Adhesion; D049109:Cell Proliferation; D002478:Cells, Cultured; D019245:Compressive Strength; D017886:Durapatite / Q000302:isolation & purification; D006358:Hot Temperature; D019344:Lactic Acid / Q000302:isolation & purification; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D011100:Polyglycolic Acid / Q000302:isolation & purification; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000302:isolation & purification; D051381:Rats; D017154:Stromal Cells / Q000166:cytology; D023822:Tissue Engineering
chemical_list: D018786:Bone Substitutes; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D017886:Durapatite