Integrated osteochondral differentiation of mesenchymal stem cells on biomimetic nanofibrous mats with cell adhesion-generated piezopotential gradients

Abstract

Biomimetic piezoelectric scaffolds provide a noninvasive way for in vivo cell regulation and tissue regeneration. Herein, considering the gradually varied piezoelectric property of native cartilage and bone tissues, we fabricated...

Recent development in multizonal scaffolds for osteochondral regeneration

“…More interestingly, it has been found that PLGA scaffolds can regenerate both cartilage and subchondral bone tissues by simply adjusting the zonal-specific pore size or porosity of scaffolds [ 207 , 208 ]. Similarly, a recent study on poly( l -lactic acid) (PLLA), a stereoisomer of , evidenced that this material could support both osteogenic and chondrogenic differentiations upon the generation of a gradient piezoelectric field [ 209 ]. Although PLGA could promote cell activities, a study has shown that it also initiated de-differentiation of chondrocytes upon adhesion, and eventually led to the deposition of type I and type X collagen impurities in the neo-formed cartilage [ 23 ].…”

“…This can be achieved by prefabricating a support layer and then produce cell-derived layers to create a multilayered scaffold [ 23 , 319 ]. Alternatively, it can be simply realized by applying external forces such as DC electric field [ 209 ] or magnetic field [ 254 , 320 ] to redistribute the prefabricated uniformed constructs with gradient properties, forming a “fake” osteochondral MZS. Here the “fake” MZSs can be defined as those without obvious layered or gradient compositions and architectures but have gradient properties or bioactive signals from top-to-bottom of the spatial coordinates in the defect area to induce zonal-specific, chondrogenic/osteogenic differentiation and osteochondral regeneration.…”

“…Regarding the “fake” osteochondral MZSs, the key point is to direct zonal-specific tissue repair by exerting the spatial property gradient rather than the compositional and structural variations. Inspired by the gradually varied piezoelectric properties of native osteochondral unit, Liu et al [ 209 ] recently designed a biomimetic electrospun PLLA nanofibrous mat (single layer) with gradient piezoelectric properties to induce OC differentiation. As shown in Fig.…”

Electrical Stimulation Enabled via Electrospun Piezoelectric Polymeric Nanofibers for Tissue Regeneration

“…The flexibility of the polymer and the electromechanical coupling of the piezoelectric material makes the piezoelectric polymer attract unprecedented research enthusiasm in selfpowered wearable sensors [32], tissue scaffold [65], and energy conversion [66]. Nevertheless, a high-intensity electric field combined with hot stretching is conventionally required for the fabrication of polymeric piezoelectric films [67].…”

“…These equations indicate that the enhancement of overall piezoelectric performance should focus on either increasing d or decreasing ε. Generally, the strategy of enhancing d is to increase the electroactive phase of the piezoelectric material [137,138] which is handily achieved by adjusting electrospinning parameters, such as electric field strength [65,139], solution concentration [140], thermal treatment [113], and drum collector rotating speed [141]. For example, Tai et al demonstrated that the nanofibrous PLLA web scaffold with finer fiber diameter was obtained via reducing the concentration of spinning solution.…”