Effect of porosities of bilayered porous scaffolds on spontaneous osteochondral repair in cartilage tissue engineering

Abstract

Poly(lactide-co-glycolide)-bilayered scaffolds with the same porosity or different ones on the two layers were fabricated, and the porosity effect on in vivo repairing of the osteochondral defect was examined in a comparative way for the first time. The constructs of scaffolds and bone marrow-derived mesenchymal stem cells were implanted into pre-created osteochondral defects in the femoral condyle of New Zealand white rabbits. After 12 weeks, all experimental groups exhibited good cartilage repairing according to macroscopic appearance, cross-section view, haematoxylin and eosin staining, toluidine blue staining, immunohistochemical staining and real-time polymerase chain reaction of characteristic genes. The group of 92% porosity in the cartilage layer and 77% porosity in the bone layer resulted in the best efficacy, which was understood by more biomechanical mimicking of the natural cartilage and subchondral bone. This study illustrates unambiguously that cartilage tissue engineering allows for a wide range of scaffold porosity, yet some porosity group is optimal. It is also revealed that the biomechanical matching with the natural composite tissue should be taken into consideration in the design of practical biomaterials, which is especially important for porosities of a multi-compartment scaffold concerning connected tissues.

Regeneration of osteochondral defects in vivo by a cell‐free cylindrical poly(lactide‐co‐glycolide) scaffold with a radially oriented microstructure

“…However, the highly interconnected structure in the O‐PLGA scaffold is efficient for substance exchange to get rid of the byproducts through peripheral blood circulation in the subchondral bone, resulting in a better regeneration compared with the R‐PLGA scaffold. Distinguished from the previous studies involving in cell‐free PLGA scaffolds for osteochondral regeneration in rabbit model in vivo (Pan et al, ), the O‐PLGA scaffold in this study can achieve significantly better regeneration in terms of apparent appearance, ECMs distribution, and simultaneous regeneration of cartilage and subchondral bone.…”

“…Even though aseptic inflammation would occur due to the degradation byproducts of PLGA after implantation, it was up‐regulated to peak at ~1 week and gradually down‐regulated to normal at ~6 weeks, which does not further impede the regeneration of osteochondral tissues (Li et al, ). In spite of plentiful positive regenerative results by using cells/bioactive molecules‐loaded PLGA scaffolds, few reports show full regeneration of osteochondral defects by implanting random porous PLGA scaffolds without combination of cells and/or bioactive molecules, regardless of the physical properties of the scaffolds, that is, pore size, porosity, and architecture (Pan et al, ). To the best of our knowledge, there is no report on the in vivo implantation of cell‐free PLGA scaffold with radially oriented pores for osteochondral regeneration.…”

Triethyl orthoformate covalently cross-linked chitosan-(poly vinyl) alcohol based biodegradable scaffolds with heparin-binding ability for promoting neovascularisation

“…It is known that the microstructure of hydrogels can influence cell infiltration, proliferation and function in tissue engineering 35,36 . The morphologies of the cross-linked CS/PVA scaffolds before and after heparin loading are shown in …”

Puerarin promotes rehabilitation of cartilage injury in juvenile rat model via inhibiting apoptosis: A mechanism study

“…In addition, puerarin was proved with protecting function on Lysosomes and mitochondria via regulating mitochondrion membrane potential [16,17]. Latest study showed that low concentration of puerarin could activate osteoblast and inhibit proliferation and differentiation of osteoclast [18][19][20]. However, there is no report about effect of puerarin on chondrocyte.…”