Oleochemical‐Tethered SBA‐15‐Type Silicates with Tunable Nanoscopic Order, Carboxylic Surface, and Hydrophobic Framework: Cellular Toxicity, Hemolysis, and Antibacterial Activity

Abstract

Novel silicates were prepared by using silylated natural fatty acids (derived from triglyceride renewable oils) as co-condensing reagents in presence of tetraethyl orthosilicate (TEOS) and the triblock copolymer, pluronic P123, as a structure directing agent. A series of carboxylic acid functionalized SBA-15-type mesoporous silicates were obtained with tunable nanoscopic order and reactive functional groups that allow the conjugation of amino probes by peptide coupling. Photophysical studies of the covalently linked aminopyrene substantiated that the internal framework of these materials have pronounced hydrophobicity. Moreover, phase separation that can emanate from the bulkiness of the starting fatty silanes has been ruled out owing to the absence of excimers after aminopyrene grafting. The hemotoxicity, cytotoxicity, and antimicrobial activity of these novel silicates were then evaluated. Without discrimination, the functionalized silicates show a significant decrease of red blood cell hemolysis as compared to bare SBA-15-silica material. Within the modified silicate series, germanium-free mesoporous silicates induce only a slight decrease in cell viability and, more interestingly, they exhibit negligible hemolytic effect. Moreover, increasing their concentration in the medium reduces the concentration of released hemoglobin as a result of Hb adsorption. Promising antimicrobial properties were also observed for these silicates with a slight dependency on whether phenylgermanium fragments were present within the silicate framework.

Chitosan-Functionalized Graphene Nanocomposite Films: Interfacial Interplay and Biological Activity

“…Thus, the percentage of hemolysis after 24 h does not reflect real hemolytic activity but is rather associated with the accumulation of hemoglobin on the surface of graphene composites. A similar effect was previously observed with functionalized-SBA-15-type mesoporous materials [48]. Significant damage of the erythrocyte membrane by GO and graphene sheets was previously reported, leading to a dose-dependent hemolytic activity on RBCs [17].…”

Phosphorylated Micro- and Nanocellulose-Filled Chitosan Nanocomposites as Fully Sustainable, Biologically Active Bioplastics

“…This result agrees with our previous results dealing with hemoglobin adsorption using chitosan-functionalized graphene nanocomposite films 42 and fatty acid-modified silica materials. 84 Increased hemolysis was also observed for CS@CNC-f and CS@MCC-f with respect to native chitosan. In contrast, the role of surface phosphorylation seems to be contradictory in comparing conjointly the behavior of CS@MCC-f and CS@P-MCC-f on the one hand and of CS@CNC-f and CS@P-CNC-f on the other hand.…”

“…To sum up, hemoglobin adsorption seems to be easier with CS@CNC- f and CS@- f , both displaying lower wettability. This result agrees with our previous results dealing with hemoglobin adsorption using chitosan-functionalized graphene nanocomposite films and fatty acid-modified silica materials . Increased hemolysis was also observed for CS@CNC- f and CS@MCC- f with respect to native chitosan.…”

Mesoporous Silica‐Based Materials with Bactericidal Properties

“…Several examples of SBA‐15 functionalized in the surface with different groups showing antibacterial activity were reported by Pędziwiatr‐Werbicka et al that used silylated natural fatty acids ( 1 ‐ 6 , derivatives of undecenoic and oleic acids, see Figure ) to functionalize the external surface of SBA‐15 particles by grafting and for the synthesis of PMOs . The different prepared materials presented several degrees of bacterial inhibition growth (in the 10–50% range) depending on the functionalization and the bacteria ( S. aureus , E. coli , S. epidermis , P. vulgaris , and P. aeruginosa ).…”