Resorbable polyesters in cartilage engineering: Affinity and biocompatibility of polymer fiber structures to chondrocytes

Abstract

The resorbable polymers polyglycolic acid (PGA) and polylactic acid (PLA) are gaining increasing importance in tissue engineering and cell transplantation. The present investigation was focused on the biocompatibility and cell retaining behavior of PGA/poly-L-lactide (PLLA) (90/10) and PLLA nonwoven structures for the in vitro development of chondrocyte-polymer constructs. The effect of the relevant monomers to chondrocytes was analyzed. Type II collagen and poly-L-lysine were compared to improve loading of PGA/PLLA and PLLA polymer nonwovens with chondrocytes. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetra-zoliumbrom ide (MTT) test was applied for quantification. At concentrations above 2 mg/mL, glycolic acid was more cytotoxic than lactic acid. As shown by pH equilibration, the cytotoxic effect is not due merely to the acidity of the alpha-hydroxy acids. Regarding the degradation products, glycolic acid, and L(+) lactic acid, nonwovens of PLLA are more biocompatible with chondrocytes than nonwovens of polyglycolide. Collagen type II and poly-L-lysine generally improved cell seeding on resorbable polymers in tissue engineering; however, their efficiency varies depending on the type of fiber structure.

Anti-Inflammatory Strategies in Cartilage Repair

“…Of the synthetic polymers, those derived from poly(a-hydroxy esters), 136 poly(propylene fumarates), 137 polyurethanes, 138 PGA, 139 and poly(lactideco-glycolide) 140 have been used for cartilage regeneration; however, inflammatory reaction due to synthetic scaffolds that impaired the quality of regenerated cartilage has also been reported in some studies. 141,142 Natural matrix scaffolds Naturally occurring polymers as scaffolds offer options for cartilage tissue engineering due to biocompatibility, biodegradability, low toxicity of degradation by-products, and plasticity in processing into a variety of material formats.…”

Cartilage tissue engineering for degenerative joint disease☆

“…Compared to fibrin, collagen, Poly(L-lactic acid) (PLLA), and poly (DL-lactic-co-glycolic acid) (PLGA), PGA was shown to provide a better scaffold for in vitro cartilage regeneration, as demonstrated by cell densities equivalent to those found in natural tissues, and by continuous cellular production of type II collagen [174]. Although such engineered constructs have also been tested for articular cartilage repair in animal models, mainly in rabbits [94,171,[175][176][177]), they have not been applied in human patients. The possible reasons include the graft induction of foreign body giant cell reaction [100] and the hydrolytic activity of the polymer substrate, which yields both toxic and partially cytotoxic degradation products.…”

Cartilage resurfacing potential of PLGA scaffolds loaded with autologous cells from cartilage, fat, and bone marrow in an ovine model of osteochondral focal defect

“…PLGA was chosen because (A) its proven biocompatibility, (B) the feasibility of threedimensional molding of the constructs in the shape of the experimental defects, (C) it allowed minimally invasive arthroscopic implantation and (D) its degradation rate, which was compatible with the expected deposition of ECM by the cells loaded on the scaffolds (Villalobos Córdoba et al 2007;Niederauer et al 2000;Sittinger et al 1996;Uematsu et al 2005). Moreover, the use of porous PLGA scaffolds permitted the retention of the cells at the defect site and promoted homogeneous distribution throughout the graft.…”