Porous thermoresponsive-co-biodegradable hydrogels as tissue-engineering scaffolds for 3-dimensional in vitro culture of chondrocytes.
A new porous, thermoresponsive, partially biodegradable, chemically crosslinked hydrogel system was developed, characterized, and tested as a cartilage tissue-engineering scaffold for in vitro chondrocyte culture over a 4-week period. The hydrogel system was composed of poly(N-isopropylacrylamide), poly(D,L-lactic acid), and dextran segments. Pores in the hydrogels were generated using a salt leaching technique. The hydrogels showed thermoresponsive properties, with a lower critical solution temperature at approximately 32 degrees C. They continuously swelled at physiological temperature in phosphate buffered saline (pH 7.4) for at least 1 month. Chondrocytes isolated from embryonic chick sterna were seeded into the hydrogel scaffolds at room temperature and cultured at 37 degrees C for 4 weeks. Real-time reverse-transcriptase polymerase chain reaction quantification was conducted every week to study messenger ribonucleic acid levels of 3 chondrocyte phenotypic markers: type II collagen, type X collagen, and Indian hedgehog. Results suggested that chondrocytes maintained their phenotype during the 4-week in vitro culture and could mimic in vivo development. Chondrocytes were non-enzymatically harvested from the hydrogel scaffold at the end of the fourth week by simply lowering the temperature from 37 degrees C to room temperature. The harvested chondrocytes kept a round morphology, confirming the maintenance of the chondrocyte phenotype in the hydrogel scaffolds.
Department of Surgery, Pennsylvania State University, Hershey, Pennsylvania 17033, USA.
Xiao
X
Huang
Yue
Y
Zhang
Henry J
HJ
Donahue
Tao L
TL
Lowe
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D002021:Buffers; D002478:Cells, Cultured; D002642:Chick Embryo; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D024043:Collagen Type II / Q000378:metabolism; D024121:Collagen Type X / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000737:chemistry; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism; D020100:Hydrogels / Q000737:chemistry / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D009924:Organ Culture Techniques; D010710:Phosphates / Q000737:chemistry; D016062:Porosity; D012333:RNA, Messenger / Q000378:metabolism; D012996:Solutions / Q000737:chemistry; D013249:Sternum / Q000166:cytology; D013696:Temperature; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
D001672:Biocompatible Materials; D015415:Biomarkers; D002021:Buffers; D024043:Collagen Type II; D024121:Collagen Type X; D003432:Cross-Linking Reagents; D053823:Hedgehog Proteins; D020100:Hydrogels; D010710:Phosphates; D012333:RNA, Messenger; D012996:Solutions