Polyester copolymer scaffolds enhance expression of bone markers in osteoblast-like cells.

In tissue engineering, the resorbable aliphatic polyester poly(L-lactide) (PLLA) is used as scaffolds in bone regeneration. Copolymers of poly(L-lactide)-co-(epsilon-caprolactone) [poly(LLA-co-CL)] and poly(L-lactide)-co-(1,5-dioxepan-2-one) [poly(LLA-co-DXO)], with superior mechanical properties to PLLA, have been developed to be used as scaffolds, but the influence on the osteogenic potential is unclear. This in vitro study of test scaffolds of poly(LLA-co-CL) and poly(LLA-co-DXO) using PLLA scaffolds as a control demonstrates the attachment and proliferation of human osteoblast-like cells (HOB) as measured by SEM and a methylthiazol tetrazolium (MTT) colorimetric assay, and the progression of HOB osteogenesis for up to 3 weeks; expressed as synthesis of the osteoblast differentiation markers: collagen type 1 (Col 1), alkaline phosphatase, bone sialoprotein, osteocalcin (OC), osteopontin and runt related gene 2 (Runx2). Surface analysis disclosed excellent surface attachment, spread and penetration of the cells into the pores of the test scaffolds compared to the PLLA. MTT results indicated that test scaffolds enhanced the proliferation of HOBs. Cells grown on the test scaffolds demonstrated higher synthesis of Col 1 and OC and also increased bone markers mRNA expression. Compared to scaffolds of PLLA, the poly(LLA-co-CL) and poly(LLA-co-DXO) scaffolds enhanced attachment, proliferation, and expression of osteogenic markers by HOBs in vitro. Therefore, these scaffolds might be appropriate carriers for bone engineering.

[1]  A Wennerberg,et al.  Determining optimal surface roughness of TiO(2) blasted titanium implant material for attachment, proliferation and differentiation of cells derived from human mandibular alveolar bone. , 2001, Clinical oral implants research.

[2]  M J Yaszemski,et al.  Polymer concepts in tissue engineering. , 1998, Journal of biomedical materials research.

[3]  Thomas D. Schmittgen,et al.  Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) Method. , 2001, Methods.

[4]  A. Albertsson,et al.  Finalizing the properties of porous scaffolds of aliphatic polyesters through radiation sterilization. , 2006, Biomaterials.

[5]  Robert Langer,et al.  Biodegradable Polymer Scaffolds for Tissue Engineering , 1994, Bio/Technology.

[6]  K. Leong,et al.  Solid freeform fabrication of three-dimensional scaffolds for engineering replacement tissues and organs. , 2003, Biomaterials.

[7]  A. H. Suzina,et al.  Gene expression analysis of osteoblasts seeded in coral scaffold. , 2008, Journal of biomedical materials research. Part A.

[8]  T. Komori,et al.  Cbfa1 in bone development. , 1998, Current opinion in genetics & development.

[9]  G. Karsenty,et al.  Osf2/Cbfa1: A Transcriptional Activator of Osteoblast Differentiation , 1997, Cell.

[10]  J. Wroblewski,et al.  Effects of titanium surfaces blasted with TiO2 particles on the initial attachment of cells derived from human mandibular bone. A scanning electron microscopic and histomorphometric analysis. , 2000, Clinical oral implants research.

[11]  T. Mosmann.  Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays. , 1983, Journal of immunological methods.

[12]  A. Albertsson,et al.  Copolymers of 1,5-dioxepan-2-one and L- or D,L-dilactide: in vivo degradation behaviour. , 1994, Journal of biomaterials science. Polymer edition.

[13]  R. Franceschi,et al.  The developmental control of osteoblast-specific gene expression: role of specific transcription factors and the extracellular matrix environment. , 1999, Critical reviews in oral biology and medicine : an official publication of the American Association of Oral Biologists.

[14]  C. Migliaresi,et al.  A study on the in vitro degradation of poly(lactic acid). , 1994, Journal of biomaterials science. Polymer edition.

[15]  Judith M Curran,et al.  The guidance of human mesenchymal stem cell differentiation in vitro by controlled modifications to the cell substrate. , 2006, Biomaterials.

[16]  A. Albertsson,et al.  Minimization of residual tin in the controlled Sn(II)octoate-catalyzed polymerization of epsilon-caprolactone. , 2008, Journal of biomedical materials research. Part A.

[17]  A. Albertsson,et al.  Elastomeric hydrolyzable porous scaffolds: copolymers of aliphatic polyesters and a polyether-ester. , 2005, Biomacromolecules.

[18]  Moustapha Kassem,et al.  Mesenchymal stem cell ingrowth and differentiation on coralline hydroxyapatite scaffolds. , 2007, Biomaterials.

[19]  A. Mak,et al.  In vitro behavior of osteoblast-like cells on PLLA films with a biomimetic apatite or apatite/collagen composite coating , 2008, Journal of materials science. Materials in medicine.

[20]  R. Dziak,et al.  Alveolar bone osteoblast differentiation and Runx2/Cbfa1 expression. , 2006, Archives of oral biology.

[21]  A. Albertsson,et al.  The influence of composition of porous copolyester scaffolds on reactions induced by irradiation sterilization. , 2008, Biomaterials.

[22]  J. Poser,et al.  Production of osteocalcin by human bone cells in vitro. Effects of 1,25(OH)2D3, 24,25(OH)2D3, parathyroid hormone, and glucocorticoids. , 1984, Metabolic bone disease & related research.

[23]  G. Karsenty,et al.  A Cbfa1-dependent genetic pathway controls bone formation beyond embryonic development. , 1999, Genes & development.

[24]  M. Kassem,et al.  Flow perfusion culture of human mesenchymal stem cells on silicate-substituted tricalcium phosphate scaffolds. , 2008, Biomaterials.

[25]  D. Marolt,et al.  Growth and differentiation of alveolar bone cells in tissue‐engineered constructs and monolayer cultures , 2008, Biotechnology and bioengineering.

[26]  A. Albertsson,et al.  Suitable Materials for Soft Tissue Reconstruction: In Vitro Studies of Cell – Triblock Copolymer Interactions , 2005 .

[27]  G. Stein,et al.  Modifications of protein-DNA interactions in the proximal promoter of a cell-growth-regulated histone gene during onset and progression of osteoblast differentiation. , 1990, Proceedings of the National Academy of Sciences of the United States of America.

[28]  P. Kasten,et al.  Porosity and pore size of beta-tricalcium phosphate scaffold can influence protein production and osteogenic differentiation of human mesenchymal stem cells: an in vitro and in vivo study. , 2008, Acta biomaterialia.

[29]  J. Aubin,et al.  Bone stem cells , 1998, Journal of cellular biochemistry.

[30]  Ann-Christine Albertsson,et al.  Covalent grafting of poly(L-lactide) to tune the in vitro degradation rate. , 2007, Biomacromolecules.

[31]  J. Vacanti,et al.  Tissue engineering : Frontiers in biotechnology , 1993 .

[32]  A. Albertsson,et al.  Surface functionalization of porous resorbable scaffolds by covalent grafting. , 2008, Macromolecular bioscience.

[33]  P. Ma,et al.  Engineering new bone tissue in vitro on highly porous poly(alpha-hydroxyl acids)/hydroxyapatite composite scaffolds. , 2001, Journal of biomedical materials research.