Surface Modification by Allylamine Plasma Polymerization Promotes Osteogenic Differentiation of Human Adipose-Derived Stem Cells

Abstract

Tuning the material properties in order to control the cellular behavior is an important issue in tissue engineering. It is now well-established that the surface chemistry can affect cell adhesion, proliferation, and differentiation. In this study, plasma polymerization, which is an appealing method for surface modification, was employed to generate surfaces with different chemical compositions. Allylamine (AAm), acrylic acid (AAc), 1,7-octadiene (OD), and ethanol (ET) were used as precursors for plasma polymerization in order to generate thin films rich in amine (-NH2), carboxyl (-COOH), methyl (-CH3), and hydroxyl (-OH) functional groups, respectively. The surface chemistry was characterized by X-ray photoelectron spectroscopy (XPS), the wettability was determined by measuring the water contact angles (WCA) and the surface topography was imaged by atomic force microscopy (AFM). The effects of surface chemical compositions on the behavior of human adipose-derive stem cells (hASCs) were evaluated in vitro: Cell Count Kit-8 (CCK-8) analysis for cell proliferation, F-actin staining for cell morphology, alkaline phosphatase (ALP) activity analysis, and Alizarin Red S staining for osteogenic differentiation. The results show that AAm-based plasma-polymerized coatings can promote the attachment, spreading, and, in turn, proliferation of hASCs, as well as promote the osteogenic differentiation of hASCs, suggesting that plasma polymerization is an appealing method for the surface modification of scaffolds used in bone tissue engineering.

Control of stem cell fate by engineering their micro and nanoenvironment

“…Benoit et al [60] , Nuttelman et al [61] , Nuttelman et al [62] , Gandavarapu et al [63] Silk fibroin NH2 hMSC osteogenic differentiation Murphy et al [59] Silk fibroin CH3 hMSC osteogenic differentiation Murphy et al [59] Glass COOH, CH3, OH, NH2 -NH2 support hMSC osteogenic differentiation Liu et al [64] Glass OH, SO3H, NH2, COOH, SH and CH3 -NH2 support hNSC differentiation Ren et al [65] Glass CH3, NH2, SH, OH and COOH NH2 and -SH-promoted and maintained hMSC Osteogenesis, -OH and -COOHpromoted and maintained chondrogenesis…”

“…Valamehr et al [96] have also used the SAM technique to create different surface hydrophobicities and found the increase in surface hydrophilicities could increase hESC proliferation and differentiation. With the emergence of plasma surface modification over the last ten years, which alters the surface chemistry with different chemical functional groups, controlling stem cell fate using chemical is likely to receive extensive research [64] .…”

Pendant small functional groups on poly(ϵ-caprolactone) substrate modulate adhesion, proliferation and differentiation of human mesenchymal stem cells

“…Due to the similarity in chemical composition (C, H and O), the spectra turned out to be similar, but with different C/O ratios, except for PCL-NH 2 film, which showed a characteristic peak of N 1 s (Fig. S2) [23]. Water contact angle was measured to assess the wettability of these films.…”

“…Among these, self-assembled monolayers (SAM), formed by a variety of alkanethiols on gold-coated glass represents an extensively exploited strategy to present small functional groups, due to the precise control over the uniformity of chemistry [13,18,[20][21][22]. Direct modifications of glass via silane derivatives or in situ plasma polymerization have also been developed [17,19,23].…”

“…Based on these above methodologies, the effects of small functional groups on adhesion, growth, migration and lineage-specific differentiation of MSCs have been systemically evaluated, and however, conflicting findings are obtained [17,[21][22][23][24]. Of note, SAM is intrinsically unstable under cell culture conditions and thus long-term evaluation of cellular behaviors has been impractical [25].…”