Chitosan/montmorillonite nanocomposite film as anticancer drug carrier: A promising biomaterial to treat skin cancers

The solvent-evaporation approach was used to produce a chitosan (CS)/montmorillonite (MMT) nanocomposite film containing the anticancer drug 5-fluorouracil (5-FU). The physicochemical and morphological characteristics, drug release profile, cytotoxic and microbiological properties of the nanocomposite films were evaluated to verify their potential as a biomaterial for the treatment of tumors. X-ray diffraction (XRD) confirmed the formation of a CS-MMT/5-FU intercalated nanocomposite and Fourier transform infrared (FTIR) detected the characteristic 5- FU bonds in the CS/5-FU and CS-MMT/5-FU nanocomposite films, suggesting successful incorporation of the drug. The addition of 5-FU to chitosan increased the contact angle from 60.5° to 65.2°, which was compensated by the incorporation of MMT, resulting in a minimum contact angle of 42.7° (maximum hydrophilicity) for CS-MMT/5-FU. This result influenced the swelling degree and the in vitro release of 5-FU. The higher hydrophilicity of CS-MMT/5-FU promoted an increase in the swelling ratio compared to the CS/5-FU nanocomposite. CS-MMT/5-FU also showed a sustained, lower 5-FU release rate with antimicrobial activity against S. aureus, E. coli and C. albicans without inducing cytotoxicity or cell death. These results can be explained by the accommodation of the drug between the MMT lamellae, which maintains the 5-FU release without affecting its microbiological activity and reducing its toxicological effects. This work demonstrates that combining montmorillonite and chitosan in a nanocomposite film has the technological potential to control the release of 5-FU, resulting in a non-toxic antimicrobial drug carrier with promising potential for the treatment of skin malignancies

Photobiomodulation reduces the cytokine storm syndrome associated with Covid-19 in the zebrafish model

Although the exact mechanism of the pathogenesis of COVID-19 is not fully understood, oxidative stress and the release of pro-inflammatory cytokines have been highlighted as playing a vital role in the pathogenesis of the disease. In this sense, alternative treatments are needed to reduce the inflammation caused by COVID-19. Therefore, this study aimed to investigate the potential effect of red PBM as an attractive therapy to downregulate the cytokine storm caused by COVID-19 from a zebrafish model. RT-PCR analyses and protein-protein interaction prediction among SARS-CoV-2 and Danio rerio proteins showed that rSpike was responsible for generating systemic inflammatory processes with significantly increased pro-inflammatory (il1b, il6, tnfa, and nfkbiab), oxidative stress (romo1) and energy metabolism (slc2a1a, coa1) mRNA markers, with a pattern like those observed in COVID-19 cases in humans. On the other hand, PBM treatment decreased the mRNA levels of these pro-inflammatory and oxidative stress markers compared with rSpike in various tissues, promoting an anti-inflammatory response. Conversely, PBM promotes cellular and tissue repair of injured tissues and significantly increases the survival rate of rSpike-inoculated individuals. Additionally, metabolomics analysis showed that the most impacted metabolic pathways between PBM and the rSpike-treated groups were related to steroid metabolism, immune system, and lipids metabolism. Together, our findings suggest that the inflammatory process is an incisive feature of COVID-19, and red PBM can be used as a novel therapeutic agent for COVID-19 by regulating the inflammatory response. Nevertheless, the need for more clinical trials remains, and there is a significant gap to overcome before clinical trials.publishedVersio