Cell activation properties of silica particles could be useful tools for immune stimulation therapy, while 10 nm NPs would be suitable for molecule transportation.
Aim: Nanoparticles (NPs) interaction with immune system is a growing topic of study. Materials & methods: Bare and amine grafted silica NPs effects on monocytes/macrophages cells were analyzed by flow cytometry, MTT test and LIVE/DEAD® viability/cytotoxicity assay. Results: Bare silica NPs inhibited proliferation and induced monocyte/macrophages activation (increasing CD40/CD80 expression besides pro-inflammatory cytokines and nitrite secretion). Furthermore, silica NPs increased cell membrane damage and reduced the number of living cells. In contrast, amine grafted silica NPs did not alter these parameters. Conclusion: Cell activation properties of bare silica NPs could be hindered after grafting with amine moieties. This strategy is useful to tune the immune system stimulation by NPs or to design NPs suitable to transport therapeutic molecules.
Skin wound healing presents a unique challenge because of its complex healing process. Herein, we developed a hydrophobic wound dressing to incorporate simvastatin, which has potential application in the treatment of ulcers and prevention of wound infection. For that matter, collagen hydrogels were grafted with dodecenylsuccinic anhydride (DDSA). The chemical modification was confirmed by FTIR and solid state 13C‐NMR spectroscopies while the ultrastructure was observed by scanning electron microscope (SEM) images. In contact angle measurements, a higher water droplet angle in DDSA‐collagen gels was observed. This was consistent with the swelling assay, in which water absorption was 5.2 g/g for collagen and 1.9 g/g for DDSA‐collagen. Additionally, viability and adhesion studies were performed. Cell adhesion decreased ~11% in DDSA‐collagen and the number of viable cells showed a tendency to decrease as DDSA concentration increased but it was only significantly lower above concentrations of 12%. Modified gels were loaded with simvastatin showing higher adsorption capacity and lower release. Lastly, the antimicrobial and anti‐inflammatory activity of DDSA‐collagen materials were assessed. DDSA‐collagen hydrogels, either unloaded or loaded with simvastatin showed sustained antimicrobial activity against Pseudomonas aeruginosa and Staphylococcus aureus for 72 hr probably due to the hydrophobic interaction of DDSA chains with bacterial cell walls. The antimicrobial activity was stronger against S. aureus. Collagen hydrogels also presented a prolonged antibacterial activity when they were loaded with simvastatin, confirming the antimicrobial properties of statins. Finally, it was observed that these materials can stimulate resident macrophages and promote an M2 profile which is desirable in wound healing processes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.