Surface characterization and cytocompatibility evaluation of silanized magnesium alloy AZ91 for biomedical applications

Abstract

Mg alloys with high Al contents have superior corrosion resistance in aqueous environments, but poor cytocompatibility compared to that of pure Mg. We have silanized the cast AZ91 alloy to improve its cytocompatibility using five different silanes: ethyltriethoxysilane (S1), 3-aminopropyltriethoxysilane (S2), 3-isocyanatopyltriethoxysilane (S3), phenyltriethoxysilane (S4) and octadecyltriethoxysilane (S5). The surface hydrophilicity/hydrophobicity was evaluated by water contact angle measurements. X-ray photoelectron analysis was performed to investigate the changes in surface states and chemical composition. All silane reagents increased adsorption of the albumin to the modified surface. In vitro cytocompatibility evaluation revealed that silanization improved cell growth on AZ91 modified by silane S1. Measurement of the concentration of Mg 2+ ions released during the cell culture indicated that silanization does not affect substrate degradation.

Natural Diatom Biosilica as Microshuttles in Drug Delivery Systems

“…The authors showed that surfaces coated with MPTMS-diatoms improved vitality and shape of the two cells lines compared to surfaces coated with simple bare diatoms. On the other hand, on surfaces coated with APTES-diatoms, the external amino groups negatively affected both the adherence and proliferation of the two cell lines, consistent with previously reported results on interactions of cell surfaces with cationic nanoparticles [42,43,44]. While surface coating with diatoms plays a crucial role in tissue integration, it was soon recognized that natural biosilica from diatoms also offers a promising biocompatible material for medicinal applications.…”

Biosilica from Living Diatoms: Investigations on Biocompatibility of Bare and Chemically Modified Thalassiosira weissflogii Silica Shells

“…Moreover, from a recent and specific study on correlation between cell viabilities and surface functionalization of silanized magnesium alloy, the amino group has been again reported to negatively promote cell adhesion and proliferation of Saos-2 cells, likely due to a supposed massive albumin subtraction from cell media [ 61 ].…”

Nanostructured Biosilica of Diatoms: From Water World to Biomedical Applications

“…On the contrary, frustules modified with amino groups hindered cell adhesion and proliferation. Amino groups have been reported to reduce cell adhesion and proliferation due to a supposed massive albumin subtraction from the cell media [85]. These results highlight the need to find the right functionalization strategy to promote cell growth on diatom-derived substrates and encourages the study of this material for further in vivo applications.…”