The fate of mesenchymal stem cells is greatly influenced by the surface chemistry of silica nanoparticles in 3D hydrogel-based culture systems.

Polymeric hydrogel-based 3D scaffolds are well-known structures, being used for cultivation and differentiation of stem cells. However, scalable systems that provide a native-like microenvironment with suitable biological and physical properties are still needed. Incorporation of nanomaterials into the polymeric systems is expected to influence the physical properties of the structure but also the stem cells fate. Here, alginate/gelatin hydrogel beads incorporated with mesoporous silica nanoparticles (MSNs) (average diameter 80.9 ±â€¯10 nm) and various surface chemistries were prepared. Human adipose-derived mesenchymal stem cells (hASCs) were subsequently encapsulated into the alginate/gelatin/silica hydrogels. Incorporation of amine- and carboxyl-functionalized MSNs (A-MSNs and C-MSNs) significantly enhances the stability of the hydrogel beads. In addition, the expression levels of Nanog and OCT4 imply that the incorporation of A-MSNs into the alginate/gelatin beads significantly improves the proliferation and the stemness of encapsulated hASCs. Importantly, our findings show that the presence of A-MSNs slightly suppresses in vivo inflammation. In contrast, the results of marker gene expression analyses indicate that cultivation of hASCs in alginate beads incorporated with C-MSNs (10% w/w) leads to a heterogeneously differentiated population of the cells, i.e., osteocytes, chondrocytes, and adipocytes, which is not appropriate for both cell culture and differentiation applications.

Stability and Antimicrobial Activity of Nisin-Loaded Mesoporous Silica Nanoparticles: A Game-Changer in the War against Maleficent Microbes.

Antimicrobial agents, such as nisin, are used extensively in the food industry. Here, we investigated various approaches to load nisin onto mesoporous silica nanoparticles (MSNs, 92 ± 10 nm in diameter), to enhance its stability and sustained release. The morphology, size, and surface charge of the as-prepared nanoparticles were analyzed using scanning transmission electron microscopy, dynamic light scattering, and ζ potential measurement. Nisin was either physically adsorbed or covalently attached to the variously functionalized MSNs, with high loading capacities (>600 mg of nisin g-1 of nanoparticles). The results of antibacterial activity analysis of nisin against Staphylococcus aureus showed that, despite the very low antibacterial activity of nisin covalently conjugated onto MSNs, the physical adsorption of nisin onto the unfunctionalized nanoparticles enhances its antimicrobial activities under various conditions, with no significant cytotoxicity effects on mouse fibroblast L929 cells. In conclusion, MSNs can be recommended as suitable carriers for nisin under various conditions.