The effect of curvature on chondrocytes migration and bone mesenchymal stem cells differentiation

Numerous cells grow in columnar tissues and organs with different curvatures and curvature gradients. Therefore, it is necessary to study the effect of curvature on cell behavior to control and promote cell development. Herein, we prepared polydimethylsiloxane (PDMS) with different micro-nano patterns using ultraviolet soft lithography. Hydrophilic polydopamine (PDA) was modified on the PDMS surface to prepare PDMS/PDA to improve its biocompatibility. The PDMS/PDA was characterized by contact angle tester and scanning electron microscopy (SEM). The effect of curvature on bone cell migration and differentiation was studied through SEM, inverted phase contrast microscope and fluorescence microscopy. We found that different curvatures had different effects on the bone cell migration and differentiation. Chondrocytes migrated rapidly in grooves with a curvature range of 1/575–1/875 μm⁻¹. Bone mesenchymal stem cells (BMSCs) had high efficiency of differentiation into chondrocytes in the grooves with a curvature range of 1/775–1/1375 μm⁻¹. Furthermore, BMSCs showed high efficiency of differentiation into chondrocytes at the edges of micro-nano patterns with different perimeter curvatures, and the differentiation efficiency was the highest at 120° convex curvature. This work shows that curvature is a principle to be considered in bone tissue regeneration engineering and provides inspiration for future biomaterials design.