Gentamicin-Ascorbic Acid Encapsulated in Chitosan Nanoparticles Improved In Vitro Antimicrobial Activity and Minimized Cytotoxicity.

Nano-drug delivery is a promising tactic to enhance the activity and minimize the cytotoxicity of antimicrobial drugs. In the current study, chitosan nanoparticles (CSNPs) were used as a carrier for the delivery of gentamicin sulfate (GM) and ascorbic acid (AA). The particles were synthesized by ionotropic gelation method and characterized by FT-IR, Zeta potential, and transmission electron microscope imaging. The obtained particles were evaluated for their in vitro antimicrobial activity and cytotoxicity. The prepared particles (GM-AA-CSNPs) under the optimal condition of 4:1:1 of chitosan to drug ratio showed encapsulation efficiency and loading capacities of 89% and 22%, respectively. Regarding biological activities, GM-AA-CSNPs showed a lower minimum inhibitory concentration (MIC) than free gentamicin sulfate and GMCSNPs mixture without presenting cytotoxicity against normal cells (HSF). Moreover, the GM-AA-CSNPs did not exhibit hemolytic activity. These results highlight that the GM-AA-CSNPs are confirmed as a hopeful formula for future investigations on the development of antimicrobial preparations.

Carnosic Acid Encapsulated in Albumin Nanoparticles Induces Apoptosis in Breast and Colorectal Cancer Cells.

Carnosic acid (CA) is a natural phenolic compound with several biomedical actions. This work was performed to study the use of CA-loaded polymeric nanoparticles to improve the antitumor activity of breast cancer cells (MCF-7) and colon cancer cells (Caco-2). CA was encapsulated in bovine serum albumin (BSA), chitosan (CH), and cellulose (CL) nanoparticles. The CA-loaded BSA nanoparticles (CA-BSA-NPs) revealed the most promising formula as it showed good loading capacity and the best release rate profile as the drug reached 80% after 10 h. The physicochemical characterization of the CA-BSA-NPs and empty carrier (BSA-NPs) was performed by the particle size distribution analysis, transmission electron microscopy (TEM), and zeta potential. The antitumor activity of the CA-BSA-NPs was evaluated by measuring cell viability, apoptosis rate, and gene expression of GCLC, COX-2, and BCL-2 in MCF-7 and Caco-2. The cytotoxicity assay (MTT) showed elevated antitumor activity of CA-BSA-NPs against MCF-7 and Caco-2 compared to free CA and BSA-NPs. Moreover, apoptosis test data showed an arrest of the Caco-2 cells at G2/M (10.84%) and the MCF-7 cells at G2/M (4.73%) in the CA-BSA-NPs treatment. RT-PCR-based gene expression analysis showed an upregulation of the GCLC gene and downregulation of the BCL-2 and COX-2 genes in cells treated with CA-BSA-NPs compared to untreated cells. In conclusion, CA-BSA-NPs has been introduced as a promising formula for treating breast and colorectal cancer.

Curcumin Loaded Chitosan-Protamine Nanoparticles Revealed Antitumor Activity Via Suppression of NF-κB, Proinflammatory Cytokines and Bcl-2 Gene Expression in the Breast Cancer Cells.

Nano drug delivery has been recently used to enhance the stability and bioavailability of chemotherapeutic agents. In this study, Chitosan/protamine nanocarrier was synthesized and used to encapsulate curcumin (CUR). The physicochemical properties of the empty carrier (CHPNPs) and curcumin-containing carrier (CU-CHPNPs) were characterized by TEM imaging, Zetasizer, and FT-IR spectroscopy. The antitumor activity of the prepared nanoparticles was assessed by determination of cell count, cell viability, the level of NF-κB, IL-6, and TNF-α and Bcl-2 gene expression in breast cancer cells (MCF-7). The results revealed that the obtained CU-CHPNPs had an average hydrodynamic size of 200 nm, zeta potential of +26.66 mv, and showed a drug encapsulation efficiency of 67%, and drug loading capacity of 40.20%. The cell-based assay showed a significant reduction in the cell viability, and NF-κB, TNF-α, and IL-6 levels upon treatment with CU-CHPNPs as compared to free CUR. Finally, the (CU-CHPNPs) downregulated the expression of the Bcl-2 anti-apoptotic gene more effectively than CUR and the CHPNPs comparing with the ß Actin housekeeping gene. This study concluded that the nano-encapsulation of CUR significantly enhances its antitumor efficacy via inhibition of NF-κB, IL-6, and TNF-α and downregulation of Bcl-2.

In vivo CD8+ T cell CRISPR screening reveals control by Fli1 in infection and cancer.

Improving effector activity of antigen-specific T cells is a major goal in cancer immunotherapy. Despite the identification of several effector T cell (TEFF)-driving transcription factors (TFs), the transcriptional coordination of TEFF biology remains poorly understood. We developed an in vivo T cell CRISPR screening platform and identified a key mechanism restraining TEFF biology through the ETS family TF, Fli1. Genetic deletion of Fli1 enhanced TEFF responses without compromising memory or exhaustion precursors. Fli1 restrained TEFF lineage differentiation by binding to cis-regulatory elements of effector-associated genes. Loss of Fli1 increased chromatin accessibility at ETS:RUNX motifs, allowing more efficient Runx3-driven TEFF biology. CD8+ T cells lacking Fli1 provided substantially better protection against multiple infections and tumors. These data indicate that Fli1 safeguards the developing CD8+ T cell transcriptional landscape from excessive ETS:RUNX-driven TEFF cell differentiation. Moreover, genetic deletion of Fli1 improves TEFF differentiation and protective immunity in infections and cancer.