Evaluation of a mPEG‐polyester‐based hydrogel as cell carrier for chondrocytes

Temperature‐sensitive hydrogels are attractive alternatives to porous cell‐seeded scaffolds and is minimally invasive through simple injection and in situ gelling. In this study, we compared the performance of two types of temperature‐sensitive hydrogels on chondrocytes encapsulation for the use of tissue engineering of cartilage. The two hydrogels are composed of methoxy poly(ethylene glycol)‐ poly(lactic‐co‐valerolactone) (mPEG‐PVLA), and methoxy poly(ethylene glycol)‐poly(lactic‐ co‐glycolide) (mPEG‐PLGA). Osmolarity and pH were optimized through the manipulation of polymer concentration and dispersion medium. Chondrocytes proliferation in mPEG‐PVLA hydrogels was observed as well as accumulation of GAGs and collagen. On the other hand, chondrocytes encapsulated in mPEG‐PLGA hydrogels showed low viability and chondrogenesis. Also, mPEG‐PVLA hydrogel, which is more hydrophobic, retained physical integrity after 14 days while mPEG‐PLGA hydrogel underwent full degradation due to faster hydrolysis rate and more pronounced acidic self‐catalyzed degradation. The mPEG‐PVLA hydrogel can be furthered tuned by manipulation of molecular weights to obtain hydrogels with different swelling and degradation characteristics, which may be useful as producing a selection of hydrogels compatible with different cell types. Taken together, these results demonstrate that mPEG‐PVLA hydrogels are promising to serve as three‐dimensional cell carriers for chondrocytes and potentially applicable in cartilage tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 3311‐3319, 2013.