Ca2+-in vivo doped biosilica from living Thalassiosira weissflogii diatoms: investigation on Saos-2 biocompatibility

Abstract

Diatoms represent a natural source of mesoporous silica whose applications range from biomedical to photonic fields. Porous hierarchically organized micro structures, the biosilica shells called frustules, can be obtained by removal of the organic biological matter from the unicellular living algae. Diatoms frustules have been investigated as scaffold for bone tissue growth taking advantage of their nanostructured surface and of the possibility to chemically modify the biosilica. Here we report on an easy way to calcium-doped biosilica supports for bone tissue regeneration by in vivo feeding the algae. FTIR and EDX analyses confirmed the incorporation of calcium into the mesopouros biosilica. Cell viability studies showed an ameliorative effect on the Saos-2 cells spreading compared with the cells grown on non-doped biosilica supports

“Outsourcing” Diatoms in Fabrication of Metal-Doped 3D Biosilica

“…The presence of calcium ions in the structure of diatom frustules was confirmed by XRD and EDXS, but no specific values were provided. Similar to Leone [ 65 ], the presence of calcium ions in the culture medium in Li et al [ 62 ] did not cause any significant changes in the morphology of diatoms, and the authors indicated that the material obtained could be used as a haemostatic. Detailed data on the conditions of doping of diatomaceous biosilica with calcium ions are given in Table 4 .…”

“…The works described above suggest that the concept of using the unique ability of diatom cultures to take up soluble metals and incorporate them into the structure of their frustules can also be applied to other metals, including nickel, europium, aluminum, zinc, iron, calcium, zirconium, and tin [ 19 , 63 , 64 , 65 , 66 , 67 , 69 , 70 , 71 ].…”

“…Leone et al [ 65 ] recently published results on the doping of diatomaceous biosilica with calcium cations for biomedical materials. The idea for this work was based on the knowledge that fibroblasts and osteoblasts grow very well on silica or ceramic substrates, and the presence of calcium ions stimulates the growth of the cells.…”

“…So far, a few publications report the ability of diatoms to metabolically introduce metal oxides such as titanium or germanium into the structure of silica frustules [ 3 , 19 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ]. There are also results of initial studies on the possibility of metabolic substitution of silicon atoms with nickel, zirconium, tin, zinc, calcium, aluminum, iron, and europium in diatomaceous biosilica [ 19 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 ].…”

Multiple Routes to Smart Nanostructured Materials from Diatom Microalgae: A Chemical Perspective

“…In a recent study by our group, for example, addition of an aqueous solution of CaCl 2 to the culture medium of Thalassiosira weissflogii diatoms resulted in in vivo incorporation of Ca 2+ cations in the frustule bulk, and this functionalization is still evident by EDX and FTIR analyses on nanostructured isolated frustules after a harsh acid‐oxidative cleaning procedure with H 2 SO 4 , KMnO 4 , and H 2 O 2 . The resulting Ca 2+ ‐enriched biosilica shells were found to be a suitable mesoporous scaffold material for growth of bone cells (osteoblast‐like), disclosing applications in regenerative medicine.…”