An amphiphilic degradable polymer/hydroxyapatite composite with enhanced handling characteristics promotes osteogenic gene expression in bone marrow stromal cells
Department of Orthopedics and Physical Rehabilitation; Department of Cell and Developmental Biology
Absorbable Implants; Animals; Bone Substitutes; Cell Differentiation; Cell Proliferation; Cells, Cultured; Durapatite; Equipment Design; Equipment Failure Analysis; Gene Expression Regulation; Hydrophobic and Hydrophilic Interactions; Lactates; Male; Materials Testing; Mesenchymal Stromal Cells; Osteoblasts; Osteogenesis; Polyethylene Glycols; Rats; *Tissue Scaffolds
Biomaterials | Cell and Developmental Biology | Molecular, Cellular, and Tissue Engineering | Orthopedics
Electrospun polymer/hydroxyapatite (HA) composites combining biodegradability with osteoconductivity are attractive for skeletal tissue engineering applications. However, most biodegradable polymers such as poly(lactic acid) (PLA) are hydrophobic and do not blend with adequate interfacial adhesion with HA, compromising the structural homogeneity, mechanical integrity and biological performance of the composite. To overcome this challenge, we combined a hydrophilic polyethylene glycol (PEG) block with poly(d,l-lactic acid) to improve the adhesion of the degradable polymer with HA. The amphiphilic triblock copolymer PLA-PEG-PLA (PELA) improved the stability of HA-PELA suspension at 25wt.% HA content, which was readily electrospun into HA-PELA composite scaffolds with uniform fiber dimensions. HA-PELA was highly extensible (failure strain>200% vs. 100 degrees for HA-PLA), and exhibited an 8-fold storage modulus increase (unlike deterioration for HA-PLA) upon hydration, owing to the favorable interaction between HA and PEG. HA-PELA also better promoted osteochondral lineage commitment of bone marrow stromal cells in unstimulated culture and supported far more potent osteogenic gene expression upon induction than HA-PLA. We demonstrate that the chemical incorporation of PEG is an effective strategy to improve the performance of degradable polymer/HA composites for bone tissue engineering applications.
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Citation: Kutikov AB, Song J. An amphiphilic degradable polymer/hydroxyapatite composite with enhanced handling characteristics promotes osteogenic gene expression in bone marrow stromal cells. Acta Biomater. 2013 Sep;9(9):8354-64. doi:10.1016/j.actbio.2013.06.013. Link to article on publisher's site
Kutikov, Artem B. and Song, Jie, "An amphiphilic degradable polymer/hydroxyapatite composite with enhanced handling characteristics promotes osteogenic gene expression in bone marrow stromal cells" (2013). University of Massachusetts Medical School Faculty Publications. 379.