PDMS-SiO2-TiO2-CaO hybrid materials – Cytocompatibility and nanoscale surface features

Abstract

Two biocompatible PDMS-SiO 2 -TiO 2 -CaO porous hybrid materials were prepared using the same base composition, precursors, and solvents, but following two different sol-gel procedures, based on the authors' previous works where for the first time, in this hybrid system, calcium acetate was used as calcium source. The two different procedures resulted in monolithic materials with different structures, microstructures, and surface wettability. Even though both are highly hydrophobic (contact angles of 127.2° and 150.6°), and present different filling regimes due to different surface topographies, they have demonstrated to be biocompatible when tested with human osteoblastic cells, against the accepted idea that high-hydrophobic surfaces are not suitable to cell adhesion and proliferation. At the nanoscale, the existence of hydrophilic silica domains containing calcium, where water molecules are physisorbed, is assumed to support this capability, as discussed.

Prospect of Metal Ceramic (Titanium-Wollastonite) Composite as Permanent Bone Implants: A Narrative Review

“…Another problem is that no micropores are present in the metals hence in a way where it is porous. This means for the metal to be viable, modification of the surfaces is required to allow cells to vascularize from the porous structure of the material [ 31 , 56 ]. This is stressed further showing that surface roughness at lateral length scales slightly larger than the size of individual bacteria, such as those found in satin surface finishes would substantially enhance bacterial colonization as compared to polished or plasma-sprayed finishes, both of which are relatively smooth at microscopic length scales.…”

Sol-gel coatings made using methyl-modified alkoxysilanes: The balance between protection and bioactivation

“…The signals Db and Dc, between -14 and -20.3 ppm, can be attributed to D2 units, which are bonded to Q units. In the PDMS-based networks, the deviation of these chemical shifts from the -23 ppm value associated to the pure PDMS is due to the nature of the first, and even the second neighbouring atom[30]. The sharp peak at -22.2 ppm in the 25P:75T spectrum corresponds…”

“…The second group is assigned to the trifunctional silicon (T units -CH3•SiO3) and their signals are comprised between shifts of -57 and -62 ppm. The chemical shifts between -80 to -110 ppm are related to tetrafunctional Q structural units (SiO4) [29].Regarding the signals in the D region, Da signal at -12 ppm is detected in the 4P:96T sample and can be associated to D groups linked to hydroxyls[30]. This signal is not detected in the sample with more PDMS, fact that is coherent with the low intensity of the 1 H NMR peak related to the presence of silanol groups.…”

PDMS-urethanesil hybrid multifunctional materials: combining CO2 use and sol–gel processing

“…materials[5,[83][84][85][86][87]. PDMS-Ormosils are especially of interest due to the possibility to tune the mechanical features[88], the optical[89] properties, and the surface energy, the permeability, as well as the biocompatibility and the bioactivity[90].PDMS-Ormosils have found applications in biosensors or as matrix materials for functionalized coating such as UVprotection, Ion-exchange, or metal corrosion protection. For example, Doro et al[91] studied coatings made by the and -22.3 ppm belong to R3-Si-(OSi) and R2-Si-(OSi)2 substructures, respectively, that majorly arise from the PDMS chain.…”