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

Abstract

In the past decade, mesoporous silica nanoparticles (MSNs) with a large surface area and pore volume have attracted considerable attention for their application in drug delivery and biomedicine. Here we propose biosilica from diatoms as an alternative source of mesoporous materials in the field of multifunctional supports for cell growth: the biosilica surfaces were chemically modified by traditional silanization methods resulting in diatom silica microparticles functionalized with 3-mercaptopropyl-trimethoxysilane (MPTMS) and 3-aminopropyl-triethoxysilane (APTES). Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses revealed that the –SH or –NH2 were successfully grafted onto the biosilica surface. The relationship among the type of functional groups and the cell viability was established as well as the interaction of the cells with the nanoporosity of frustules. These results show that diatom microparticles are promising natural biomaterials suitable for cell growth, and that the surfaces, owing to the mercapto groups, exhibit good biocompatibility.

Exploratory Testing of Diatom Silica to Map the Role of Material Attributes on Cell Fate

“…Cicco et al . 23 and Yu et al . 35 however, observed higher ratios of 5 ( T. Weissflogii ) and 3 (diatomaceous earth) respectively.…”

“…There are currently estimated to be over 200,000 different diatom species, each with their own unique shape and morphology 15 , 18 , 22 . This offers a huge array of surface topographies, particle sizes and shapes, which could be used to help understand the role of silica in bone repair and the influence of material attributes on the cell response.…”

“…This offers a huge array of surface topographies, particle sizes and shapes, which could be used to help understand the role of silica in bone repair and the influence of material attributes on the cell response. A recent study by Cicco et al ., tested the cell response of the diatom Thalassiosira Weissflogii using osteoblastic (Saos-2) and fibroblastic (NHDF) cell lines, and found no adverse cellular response to diatom frustules 23 . Cicco’s study provides a useful insight into the cellular biocompatibility of diatoms as an orthopedic implant or wound healing material, however, does not investigate the pro-inflammatory response, which is the most common cause of implant failure 24 .…”

Data from in vivo functionalization of diatom mesoporous biosilica with bisphosphonates

“…An additional control made of cells grown on glass slides in presence of lone ALE solution (10 −6 M) was used. After 24 and 96 h of incubation, cells were fixed in 4% of paraformaldehyde/PBS solution (20′) and stained for 3’ with a dye solution (0.2% Coomassie Brilliant Blue R250 Sigma, 50% methanol, 10% acetic acid) [9] . After PBS washings for removing the excess of dye, cells were microscopically evaluated ( Fig.…”

Optimizing the Design of Diatom Biosilica-Targeted Fusion Proteins in Biosensor Construction for Bacillus anthracis Detection

“…Diatoms are a group of unicellular microalgae, often with a highly silicified, mesoporous cell wall (frustule) exhibiting nano-to meso-scale hierarchical architecture [1][2][3]. Extraction of diatom frustules can be accomplished through acid washing (e.g., [4,5]) to remove all organic components, or by detergent extraction [6] to retain the protein complement. Acid washed diatom frustules resemble de novo assembled mesoporous silica nanoparticles [7,8].…”