Search

Osteopontin (OPN) is a key mediator of cell interactions with biomaterials. However, few studies have been dedicated to studying cell adhesion on OPN-adsorbed substrates with controlled charge and wettability. Here, amino-carboxyl (NH 2 /COOH) and hydroxyl-methyl (OH/CH 3 ) mixed self-assembled monolayers (SAMs) of varying charges and wettability, respectively, were used as controllable model surfaces to study OPN adsorption and subsequent mesenchymal stem cell (MSC) adhesion. The amount of OPN adsorbed onto the NH 2 /COOH mixed SAMs appeared to monotonically depend on the surface charge, whereas only a moderately hydrophilic surface was conducive to OPN adsorption on OH/CH 3 mixed SAMs. The results correlated well with cell spreading on OPN-coated surfaces in a serum-free medium culture. In addition, the OH/CH 3 mixed SAMs with moderate wettability tended to promote β 1 , β 3 , α v and α 5 integrins, indicating that wettability may guide cell adhesion by mediating the integrins signaling pathway. This work will have reference value for designing biologically responsive substrate surfaces.

Self-assembled monolayers (SAMs) of alkanethiols on gold are highly controllable model substrates and have been employed to mimic the extracellular matrix for cell-related studies. This study aims to systematically explore how surface chemistry influences the adhesion, morphology, proliferation and osteogenic differentiation of mouse mesenchymal stem cells (mMSCs) using various functional groups (-OEG, -CH 3 , -PO 3 H 2 , -OH, -NH 2 and -COOH). Surface analysis demonstrated that these functional groups produced a wide range of wettability and charge: -OEG (hydrophilic and moderate iso-electric point (IEP)), -CH 3 (strongly hydrophobic and low IEP), -PO 3 H 2 (moderate wettability and low IEP), -OH (hydrophilic and moderate IEP), -NH 2 (moderate wettability and high IEP) and -COOH (hydrophilic and low IEP). In terms of cell responses, the effect of wettability may be more influential than charge for these groups. Moreover, compared to -OEG and -CH 3 groups, -PO 3 H 2 , -OH, -NH 2 and -COOH functionalities tended to promote not only cell adhesion, proliferation and osteogenic differentiation but also the expression of α v and β 1 integrins. This finding indicates that the surface chemistry may guide mMSC activities through α v and β 1 integrin signaling pathways. Model surfaces with controllable chemistry may provide insight into biological responses to substrate surfaces that would be useful for the design of biomaterial surfaces., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Microscale hollow Mg-doped calcium carbonate was fabricated using yeast cell as biotemplate. The yeasts pre-adsorbed magnesium metabolically due to special biosorption for metallic ions. Vaterite was preferably formed rather than calcite during the fabrication in which yeast biotemplate with high Mg 2+ content was used, and a larger amount of magnesium was also doped within. When being co-cultured with mouse mesenchymal stem cells, the vaterite/calcite composite microcapsules with high Mg content revealed a better cytocompatibility than the calcite microcapsules without Mg or with less Mg content. This study is expected to promote the development of novel biomimetic materials. [ABSTRACT FROM AUTHOR]