Roles of Hydroxyapatite Allocation and Microgroove Dimension in Promoting Preosteoblastic Cell Functions on Photocured Polymer Nanocomposites through Nuclear Distribution and Alignment

Abstract

This study clarifies how hydroxyapatite (HA) allocation and microgroove dimension affect mouse preosteoblastic MC3T3-E1 cell functions on microgrooved substrates of polymer nanocomposites. Using replica molding from micromachined silicon wafer templates, we fabricated photocured poly(ε-caprolactone) triacrylate (PCLTA)/HA nanocomposite substrates with parallel microgrooves (two groove widths of 5 and 15 μm and one groove depth of 5 μm). Four types of microgrooved substrates were made: "homogeneous" ones of PCLTA and PCLTA/HA with uniform distribution and two "heterogeneous" laminated microgrooved substrates with HA only in the PCLTA matrix in the ridges or bottom. These substrates were used to regulate MC3T3-E1 cell attachment, proliferation, alignment, nuclear circularity and distribution, and mineralization. MC3T3-E1 cell attachment and proliferation were much higher on the microgrooved substrates of PCLTA/HA than on those of PCLTA, in particular, on the 5 μm wide microgrooved substrate with PCLTA/HA ridges and PCLTA bottom. The shape and distribution of MC3T3-E1 cytoskeleton and nuclei were altered by the substrate topography and HA allocation. For 5 μm wide heterogeneous microgrooved substrates with HA only in the ridges, MC3T3-E1 cells exhibited better spreading perpendicular to the microgrooves but tended to extend along the microgrooves containing HA in the bottom. The widest cells and the roundest/largest cell nuclei were observed on the heterogeneous substrate with PCLTA/HA ridges, while the narrowest cells with the best elongation were found on the homogeneous PCLTA/HA substrate. The trend in MC3T3-E1 cell mineralization on the substrates was consistent with that in cell/nuclear elongation. Osteocalcin mRNA expression was significantly higher on the PCLTA/HA substrates than on the PCLTA ones and also on the microgrooved substrates of PCLTA/HA than on the flat ones, regardless of the groove width of 5 or 15 μm.

Cross‐linkable graphene oxide embedded nanocomposite hydrogel with enhanced mechanics and cytocompatibility for tissue engineering

“…[32][33][34] To increase the amount of surface hydroxyl groups, excess Tris was reacted with GO to transform the epoxy groups on the GO basal plane into hydroxyl groups. 35,36 The synthesized GO and GO-TrisA exhibit a light or dark brown color, as shown in Figure 2(A). 35,36 The synthesized GO and GO-TrisA exhibit a light or dark brown color, as shown in Figure 2(A).…”

Silicon microgrooves for contact guidance of human aortic endothelial cells

“…In particular, adhesion and orientation of endothelial cells on different surfaces can be controlled by combining surface chemical treatment and topography mimicking the elongated endothelium characteristic of the blood vessels [11]. A broad range of techniques and materials have been employed to fabricate well-defined topographical and chemical cues to assess cell micropatterning [12–16]. Some of these approaches are based on photolithography and reactive ion etching that in some cases are followed by anisotropic etching [17].…”

Time‐dependent combinatory effects of active mechanical loading and passive topographical cues on cell orientation

“…In particular, linear micro/nanoscale grooves/ridges on two‐dimensional (2D) substrates have attracted great research attentions for years due to their paramount roles in regulating cell orientation for a variety of cell types, including fibroblasts, epithelial cells, endothelial cells, smooth muscle cells, and neuronal cells, where the contact guidance promotes focal adhesion and aligns cells along these grooves/ridges (Beduer et al, ; Dewey et al, ; Lee et al, ; Loesberg et al, ; Saez et al, ). The degree of alignment varies with the characteristic dimensions of the microstructures (Gilchrist et al, ; Henry et al, ; Hu et al, ; Lucker et al, ).…”