In Vitro Culture of Chondrocytes in a Novel Thermoreversible Gelation Polymer Scaffold Containing Growth Factors

Abstract

In this study we examined the potential of a novel thermoreversible gelation polymer (TGP) to act as a 3-D hydrogel scaffold and deliver both chondrocytes and growth factors. Chondrocytes obtained from bovine articular cartilage were studied as a suspension in TGP chilled to 4 degrees C, in the presence or absence of the growth factors IGF-1 and/or TGF beta2. The cold cell/aqueous suspensions were injected into a cylindrical mold and cultured at 37 degrees C for up to 16 weeks. Specimens obtained at 12 and 16 weeks were semitranslucent and elastic. The matrices surrounding the chondrocytes were histologically positive to Safranin-O staining and type II collagen staining. The glycosaminoglycan and hydroxyproline contents in the specimens increased as a function of time and because of the presence of growth factors; those cultured with growth factors produced significantly more of these substances than those cultured without. We have concluded that TGP has potential as a scaffold material in the generation of tissue-engineered cartilage in vitro.

Hydrogels for the Repair of Articular Cartilage Defects

“…Aqueous solutions undergo gelation at a lower critical solution temperature that can be increased or decreased through the modification of the PNIPAAm polymer with more hydrophobic or hydrophilic polymers, respectively. 160 These hydrogels are nondegradable and have been investigated in vitro for cartilage formation by chondrocytes and MSCs under several conditions, such as the presence of growth factors or in coculture systems. 160,161 PNIPAAm hydrogels have also been modified with chitosan and with gelatin, allowing control over cell-matrix interactions.…”

Tissue Engineered Trachea Using Decellularized Aorta

“…This belief guided our group to focus on using aorta because of its flexibility, and similar size and tubular shape to the human trachea. However, as shown by Tsukada and colleagues [26], using an aortic allograft alone for tracheal replacement leads to necrosis with calcifications or connective tissue replacement of the allograft. Furthermore, the allograft showed no signs of angiogenesis or even evidence of tracheal cartilage regeneration.…”

“…Our group has previously demonstrated the feasibility of engineering a trachea using PGA, a thermo reversible hydrogel (pluronic F127) [22] and a thermo reversible gelation polymer (TGP) [26] alone. These past results showed mature and adequate engineered cartilage in a tracheal shape in an animal model with a T cell deficiency.…”

Design and preparation of polymeric scaffolds for tissue engineering

“…The methods of tissue engineering have been applied to different types of tissue, including skin [7][8][9][10][11], bone [12][13][14][15][16], liver [17][18][19][20][21], intestine [22][23][24][25][26][27], esophagus [28][29][30][31][32], valve leaflets [33][34][35][36], muscle [37][38][39] and tongue [40][41][42], the vascular system [43][44][45][46][47], for craniofacial defects [48][49][50], tendons and ligaments [51][52][53][54][55], cartilage [56][57][58][59][60] and nerve tissue [61][62][63][64][65]. Since the early commercialization of tissue-engineered applications, for example, the work of Bell and colleagues [66], research with stem cells [3,[67][68][69] and the use of growth factors [70][71][72][73] that support cell differentiation and proliferation, have provided new opportunities in the field of tissue engineering. At present, tissue engineering methods generally require the use of a porous scaffold that serves as a matrix for initial cell attachment and subsequently for tissue formation in vitro and in vivo.…”