The effect of porosity and mechanical property of a synthetic polymer scaffold on repair of osteochondral defects

Abstract

We have made three types of poly (DL-lactide-coglycolide) (PLG) scaffolds (porosity: scaffold I 80±0.9%, II 85±0.8%, III 92±0.7%; compression module determined with 10% strain: scaffold I 0.26 MPa, II 0.091 MPa, III 0.0047 MPa). Osteochondral defects made in the femoral condyle of rabbits were treated with these scaffolds and the possibilities of cartilage repair were investigated histologically. At post-operative weeks 6 and 12, histological scores in the groups of scaffolds II and III were significantly higher than the score in the group of scaffold I. Scaffolds II and III, which have higher porosity than scaffold I, allow better migration of bone marrow cells and better replacement of the scaffold with bone and cartilage than scaffold I. This study suggests that higher porosity allowing bone marrow cells to migrate to the scaffold is important in repairing osteochondral defects.Résumé Nous avons réalisé trois types de montage PLG (DL lactide co glycolide) avec des porosités différentes (montage I à 0,9%, montage II à 87 ,8%, montage III 0,7%). Avec le module de compression a été imposée une tension de 10% avec 0,26 MPa au niveau de la pièce I, 0,091 Mpa en montage II et 0,0047 MPa en montage III). Un defect ostéochondral réalisé dans le condyle fémoral d'un lapin a été traité par ces trois procédés avec une possibilité de réparation cartilagineuse. Cette possibilité a été évaluée histologiquement. A 6 et 12 semaines postopératoires, le score histologique dans les groupes II et III sont significativement plus élevés que dans le groupe I. Les pièces II et III qui ont une plus grande porosité que la I permettent une meilleure migration des cellules de la moelle osseuse et une meilleure réparation de l'os et du cartilage que dans le montage I. Cette étude nous permet de penser qu'une porosité plus importante permet la migration plus facile de ces cellules de moelle osseuse lors de la réparation des défects ostéochondraux.

Potency of double-layered Poly L-lactic Acid scaffold in tissue engineering of tendon tissue

“…However, in an in vivo study the best porosity of scaffold may be one that changes relative to the condition. In a cartilage repair study, Ikeda et al reported that a lower porosity of poly (DL-lactide-co- glycolide) (PLG) scaffolds inhibits cell migration and a higher porosity leads to weakness in the regenerated tissue [13]. Ozaki et al compared three forms of PTFE scaffold (PTFE felt, fabric and mesh) and concluded that the felt type scaffold had higher cell migration than the other structures [20].…”

Ligament regeneration using an absorbable stent-shaped poly-l-lactic acid scaffold in a rabbit model

“…Many previous studies have used the combination of scaffolds with either growth factors or cultured cells [14][15][16] to encourage cell retention and migration within the scaffolds. The high-density scaffolds, however, were largely unable to maintain any migrated cells within their interstices [17]. Therefore, we designed the scaffold in a stent shape, so that it contains fewer synthetic fibres.…”

Facile fabrication of mesoporous poly(ethylene- co -vinyl alcohol)/chitosan blend monoliths

“…By measuring the weights of a cross-linked blend monolith in its dry state and wet (swollen) state, the weight swelling ratio was calculated as 450% (Park et al, 2013). Moreover, the total porosity was calculated as 83% by gravimetry using the equation described in the literature (Ikeda et al, 2009). …”