Delivery of dexamethasone, ascorbate, and growth factor (TGF β-3) in thermo-reversible hydrogel constructs embedded with rabbit chondrocytes

The aim of this study was to assess the efficacy of poly(N-isopropylacrylamide-co-acrylic acid) (p(NiPAAm-co-AAc)) as an injectable drug delivery vehicle and a cell therapeutic agent in the form of a supporting matrix for the chondrogenic differentiation of rabbit chondrocytes. The p(NiPAAm-co-AAc) hydrogel itself without specific differentiation-inducing drugs was used as a control in order to determine the effects of these materials on chondrogenic differentiation. The level of cartilage associated extracellular matrix (ECM) proteins was examined by immunohistochemical staining for collagen type II as well as Safranin-O and Alcian blue (GAG) staining. These results highlight the potential of a thermo-reversible hydrogel mixed with chondrocytes and differentiation materials as an injectable delivery vehicle for use in neocartilage formation. (c) 2006 Elsevier Ltd. All rights reserved.