title: Manipulations in hydrogel degradation behavior enhance osteoblast function and mineralized tissue formation.
abstract: Hydrogels were prepared by copolymerizing a degradable macromer, poly(lactic acid)-b-poly(ethylene glycol)-b-poly(lactic acid) endcapped with methacrylate groups (PEG-LA-DM), with a nondegradable macromer, poly(ethylene glycol) dimethacrylate (PEGDM). Copolymer networks consisted of 100:0, 83:17, 67:33, and 50:50 PEGDM:PEG-LA-DM mass%, essentially creating scaffolds that exhibit 0, 17, 33, and 50% degradation over the time course of the experiment. Osteoblasts were photoencapsulated in these copolymer hydrogels and cultured for 3 weeks in vitro. Metabolic activity, proliferation, and alkaline phosphatase production were enhanced by an increase PEG-LADM content and corresponding degradation. Gene expression of the cultured osteoblasts, normalized to beta-actin, was analyzed, and osteopontin and collagen type I gene expression increased with degradation. Finally, as a measure of mineralized tissue formation, calcium and phosphate deposition was analyzed biochemically and histologically. Mineralization increased with increasing concentration of PEG-LA-DM and biochemically resembled that of hydroxyapatite.
authors.affiliation: Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309-0424, USA.
authors.forename: Danielle S W
authors.initials: DS
authors.lastname: Benoit
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Durney
authors.forename: Kristi S
authors.initials: KS
authors.lastname: Anseth
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001672:Biocompatible Materials / Q000378:metabolism*; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000378:metabolism*; D020100:Hydrogels / Q000378:metabolism*; D010006:Osteoblasts / Q000502:physiology*; D051381:Rats
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels