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Targeted drug delivery and increasing the biological activity of drugs is one of the recent challenges of pharmaceutical researchers. Niosomes are one of the new targeted drug delivery systems that enhances the biological properties of drugs. In this study, for the first time, the green synthesis of selenium nanoparticles (SeNPs), and its loading into niosome was carried out to increase the anti-bacterial and anti-cancer activity of SeNPs. Different formulations of noisome-loaded SeNPs were prepared, and the physical and chemical characteristics of the prepared niosomes were investigated. The antibacterial and anti-biofilm effects of synthesized niosomes loaded SeNPs and free SeNPs against standard pathogenic bacterial strains were studied, and also its anticancer activity was investigated against breast cancer cell lines. The expression level of apoptotic genes in breast cancer cell lines treated with niosome-loaded SeNPs and free SeNPs was measured. Also, to evaluate the biocompatibility of the synthesized niosomes, their cytotoxicity effects against the human foreskin fibroblasts normal cell line (HFF) were studied using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. The results illustrated that the optimal formulation had an average size of 177.9 nm, a spherical shape, and an encapsulation efficiency of 37.58%. Also, the results revealed that the release rate of SeNPs from niosome-loaded SeNPs and free SeNPs was 61.26% and 100%, respectively, in 72 h. Also, our findings demonstrated that the niosome-loaded SeNPs have significant antibacterial, anti-biofilm, and anticancer effects compared to the free SeNPs. In addition, niosome-loaded SeNPs can upregulate the expression level of Bax, cas3, and cas9 apoptosis genes while the expression of the Bcl2 gene is down-regulated in all studied cell lines, significantly. Also, the results of the MTT test indicated that the free niosome has no significant cytotoxic effects against the HFF cell line which represents the biocompatibility of the synthesized niosomes. In general, based on the results of this study, it can be concluded that niosomes-loaded SeNPs have significant anti-microbial, anti-biofilm, and anti-cancer effects, which can be used as a suitable drug delivery system.

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Background: Evidence of COVID-19 respiratory sequels is restricted and predisposing factors are not well studied more than two years passing pandemic. This study followed COVID-19 patients 12 weeks after discharge from hospital for respiratory sequels. Materials and Methods: This was a prospective study on discharged COVID-19 patients in 2021, in Jahrom, Iran. Exposure was COVID-19 clinical features at hospitalization, including symptoms and physical examination and laboratory findings, and primary endpoint was 12-week lung sequel, being evaluated by a chest CT scan. Demographics and previous medical history were considered covariates. SPO2 and CRP  6-week changes were followed as an early tool for prediction of 12-week lung sequel. Results: Totally, 383 participants (17 had sequels) with mean age of 57.43±18.03 years old (50.13% male) completed 12-week study follow-ups. Ninety-one (23.8%) subjects had an ICU admission history.  SPO2% in 6th week was statistically significantly associated with a higher rate of 12-week sequelae (p<0.001). Also, patients having CT scan scores between 40% to 50%  (p=0.012)  and higher than 50% (p=0.040) had higher chance of experiencing lung sequelae than patients with CT scan score of below 40%, as well as having ICU admission history and lower SPO2% at 6th week of discharge.  There was a statistically significant increasing trend of SPO2% (P<0.001) and a statistically significant decreasing trend of CRP levels (P<0.001), overall. SPO2% increase after 6 weeks was lower in participants with lung sequels than fully improved ones (P=0.002) and as well as total 12-week change in SPO2% (P=0.001). CRP changes in none of evaluated periods were different among study groups (P>0.05). Conclusion: Our results were in favor of closely following SPO2 levels after patient discharge, while CRP assessment seems not helpful based on our results.