title: Manipulations in hydrogel chemistry control photoencapsulated chondrocyte behavior and their extracellular matrix production.
abstract: In engineering a cell-carrier to support cartilage growth, hydrogels provide a unique, largely aqueous environment for 3-dimensional chondrocyte culture that facilitates nutrient transport yet provides an elastic framework dictating tissue shape and supporting external loads. Although the gel environment is often >90% water, we demonstrate that slight variations in hydrogel chemistry control gel degradation, evolving macroscopic properties, and ultimately the secretion and distribution of extracellular matrix molecules. Specifically, biodegradable poly(ethylene glycol)-co-poly(lactic acid) hydrogels were fabricated via photopolymerization. When chondrocytes were photoencapsulated in these gels, changes in the poly(ethylene glycol)-co-poly(lactic acid) repeat unit ratio from 19 to 7 increased total collagen synthesis 2.5-fold after 6 weeks in vitro. Furthermore, the ratio of collagen to glycosaminoglycans varied from glycosaminoglycan-rich, 0.33 +/- 0.13, to collagen-rich, 4.58 +/- 1.21, depending on gel chemistry and in vitro versus in vivo culture environment. By tuning scaffold chemistry, and subsequently, gel structure and degradation behavior, we can better guide tissue evolution and development.
authors: Department of Chemical Engineering, University of Colorado, ECCH 111, Boulder, Colorado 80309-0424, USA.
authors: Stephanie J
authors: SJ
authors: Bryant
authors: Kevin L
authors: KL
authors: Durand
authors: Kristi S
authors: KS
authors: Anseth
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D002417:Cattle; D017690:Cell Transplantation / Q000379:methods*; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D024043:Collagen Type II / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D005260:Female; D006025:Glycosaminoglycans / Q000378:metabolism; D020100:Hydrogels / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry; D051379:Mice; D008819:Mice, Nude; D011091:Polyesters; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D023822:Tissue Engineering
chemical_list: D001672:Biocompatible Materials; D024043:Collagen Type II; D006025:Glycosaminoglycans; D020100:Hydrogels; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; D011092:Polyethylene Glycols; C033616:poly(lactide)