title: Radially and axially graded multizonal bone graft substitutes targeting critical-sized bone defects from polycaprolactone/hydroxyapatite/tricalcium phosphate.
abstract: Repair and regeneration of critical sized defects via the utilization of polymeric bone graft substitutes are challenges. Here, we introduce radially and axially graded multizonal bone graft substitutes fabricated from polycaprolactone (PCL), and PCL biocomposites with osteoconductive particles, that is, hydroxyapatite (HA), and β-tricalcium phosphate (TCP). The novel bone graft substitutes should provide a greater degree of freedom to the orthopedic surgeon especially for repair of critically sized bone defects. The modulus of the graft substitute could be tailored in the axial direction upon the systematic variation of the HA/TCP concentration, while in the radial direction the bone graft substitute consisted of an outer layer with high stiffness, encapsulating a softer core with greater porosity. The biocompatibility of the bone graft substitutes was investigated using in vitro culturing of human bone marrow-derived stromal cells followed by the analysis of cell proliferation and differentiation rates. The characterization of the tissue constructs included the enzymatic alkaline phosphates (ALP) activity, microcomputed tomography imaging, and polymerase chain reaction analysis involving the expressions of bone markers, that is, Runx2, ALP, collagen type I, osteopontin, and osteocalcin, overall demonstrating the differentiation of bone marrow derived stem cells (BMSCs) via osteogenic lineage and formation of mineralized bone tissue.
authors: Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey, USA.
authors: Asli
authors: A
authors: Ergun
authors: Xiaojun
authors: X
authors: Yu
authors: Antonio
authors: A
authors: Valdevit
authors: Arthur
authors: A
authors: Ritter
authors: Dilhan M
authors: DM
authors: Kalyon
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000494:pharmacology; D015415:Biomarkers; D018786:Bone Substitutes / Q000138:chemical synthesis / Q000494:pharmacology; D002113:Calcification, Physiologic / Q000187:drug effects; D002130:Calcium Phosphates; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D019245:Compressive Strength; D017886:Durapatite; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D009928:Organ Specificity; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects; D011091:Polyesters; D016062:Porosity; D013499:Surface Properties; D059467:Transcriptome; D055114:X-Ray Microtomography
chemical_list: D001672:Biocompatible Materials; D015415:Biomarkers; D018786:Bone Substitutes; D002130:Calcium Phosphates; D011091:Polyesters; C485817:beta-tricalcium phosphate; C016240:polycaprolactone; D017886:Durapatite; C548267:ALPL protein, human; D000469:Alkaline Phosphatase