Electrospun PLGA nanofiber scaffolds for articular cartilage reconstruction: mechanical stability, degradation and cellular responses under mechanical stimulation in vitro

Abstract

We investigated the potential of a nanofiber-based poly(DL-lactide-co-glycolide) (PLGA) scaffold to be used for cartilage reconstruction. The mechanical properties of the nanofiber scaffold, degradation of the scaffold and cellular responses to the scaffold under mechanical stimulation were studied. Three different types of scaffold (lactic acid/glycolic acid content ratio = 75 : 25, 50 : 50, or a blend of 75 : 25 and 50 : 50) were tested. The tensile modulus, ultimate tensile stress and corresponding strain of the scaffolds were similar to those of skin and were slightly lower than those of human cartilage. This suggested that the nanofiber scaffold was sufficiently mechanically stable to withstand implantation and to support regenerated cartilage. The 50 : 50 PLGA scaffold was degraded faster than 75 : 25 PLGA, probably due to the higher hydrophilic glycolic acid content in the former. The nanofiber scaffold was degraded faster than a block-type scaffold that had a similar molecular weight. Therefore, degradation of the scaffold depended on the lactic acid/glycolic acid content ratio and might be controlled by mixing ratio of blend PLGA. Cellular responses were evaluated by examining toxicity, cell proliferation and extracellular matrix (ECM) formation using freshly isolated chondrocytes from porcine articular cartilage. The scaffolds were non-toxic, and cell proliferation and ECM formation in nanofiber scaffolds were superior to those in membrane-type scaffolds. Intermittent hydrostatic pressure applied to cell-seeded nanofiber scaffolds increased chondrocyte proliferation and ECM formation. In conclusion, our nanofiber-based PLGA scaffold has the potential to be used for cartilage reconstruction.

Nanostructured materials for applications in drug delivery and tissue engineering

“…Many studies have been carried out in the application of polymer nanofibers in the tissue engineering of bone [159], blood vessel [160], cartilage [161][162][163], cardiac tissue [164], peripheral nerve system [165], ligaments [166], liver [167] and skin [162]. In most of these studies, biodegradable polymer materials such as PCL, PLA, PGA and PLGA were used.…”

Polymeric Nanofibers in Tissue Engineering

“…89 Finally, reduction in fiber diameter and increase in surface area increases the rate of diffusion of degradation byproducts from the fibers, which could decrease the rate of autocatalytic degradation. [89][90][91][92] It is likely that all three of these factors play a role in polymeric nanofiber degradation and should be taken into consideration when designing nanofibrous constructs for tissue engineering. Further, the material composition of polymeric nanofibers should be tailored to the intended application to support tissue growth or the release of bioactive factors over the proper time course.…”

Bioengineering of Articular Cartilage: Past, Present and Future

“…Degradation by-products has been shown to elicit inflammatory response and decreased pH level [98] Mechanical stiffness can sometimes be undesirable [196] Hydrophobicity [196] [197]; [198]; [199]; [197]; [200]; [201]; [202]; [203]; [204]; [205];;…”