Synthetic lethality is a molecular-targeted therapy for selective killing of cancer cells. We exploited a lethal interaction between superoxide dismutase 1 inhibition and Bloom syndrome gene product (BLM) defect for the treatment of colorectal cancer (CRC) cells (HCT 116) with a customized lung cancer screen-1-loaded nanocarrier (LCS-1-NC). The drug LCS-1 has poor aqueous solubility. To overcome its limitations, a customized NC, composed of a magnetite core coated with three polymeric shells, namely, aminocellulose (AC), branched poly(amidoamine), and paraben-PEG, was developed for encapsulating LCS-1. Encapsulation efficiency and drug loading were found to be 74% and 8.2%, respectively. LCS-1-NC exhibited sustained release, with ∼85% of drug release in 24 h. Blank NC (0.5 mg/mL) exhibited cytocompatibility toward normal cells, mainly due to the AC layer. LCS-1-NC demonstrated high killing selectivity (104 times) toward BLM-deficient HCT 116 cells over BLM-proficient HCT 116 cells. Due to enhanced efficacy of the drug using NC, the sensitivity difference for BLM-deficient cells increased to 1.7 times in comparison to that with free LCS-1. LCS-1-NC induced persistent DNA damage and apoptosis, which demonstrates that LCS-1-NC effectively and preferentially killed BLM-deficient CRC cells. This is the first report on the development of a potential drug carrier to improve the therapeutic efficacy of LCS-1 for specific killing of CRC cells having BLM defects.

Rheumatoid arthritis (RA) is the most prevalent autoimmune disease affecting about 1% world population. Zinc (Zn) is necessary for the maintenance of bone homeostasis and the level of Zn was reported to be decreased in RA patients and collagen-induced arthritic rats. Effective delivery of Zn has been reported using zinc gluconate but oral absorption of Zn from zinc gluconate (ZG) is very low in humans. Zn supplementation reduces disease severity in patients suffering from chronic, refractory RA and exerts mild and transient side effects. The aim of this study was to synthesize and characterize zinc gluconate-loaded chitosan nanoparticles (ZG-Chit NPs) and to evaluate and compare therapeutic efficacy of ZG-Chit NPs and zinc gluconate against collagen-induced RA in Wistar rats. The nanoparticles were formulated by ionic gelation method and the hydrodynamic diameter was 106.5 ± 79.55 nm as measured using DLS. The particle size, shape, and surface morphology was further confirmed by transmission electron microscopy, scanning electron microscopy, and atomic force microscopy. These nanoparticles showed good cytocompatibility against foreskin fibroblasts (BJ) and L929 cells. Arthritic rats were treated with ZG (20 mg/kg body weight, intraperitoneally) and equivalent doses of ZG-Chit NPs. The treatment of both ZG and ZG-Chit NPs reduced the severity of arthritis as evidenced by reduced joint swelling, erythema, and edema but ZG-Chit NPs exhibited superior efficacy. Furthermore, it was found that ZG and ZG-Chit NPs attenuate biomarkers of inflammation (C-reactive protein, myeloperoxidase, nitric oxide, TNF-α, and IL-1β) and oxidative stress (articular elastase, lipid peroxidation, catalase, glutathione, and superoxide dismutase). The results of the histopathology further confirmed that ZG-Chit NPs markedly suppressed infiltration of inflammatory cells as compared to ZG at the ankle joint tissue. Immunohistochemical analysis also revealed that treatment with ZG-Chit NPs resulted in reduced pro-inflammatory marker (TNF-α, IL-6, and iNOS) expression and enhanced SOD1 expression. Overall, this study suggests that ZG and ZG-Chit NPs suppressed the severity of arthritis plausibly mediated by attenuation of inflammation and oxidative stress and more importantly ZG-Chit NPs exhibited superior efficacy as compared to ZG.

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Rheumatoid arthritis is a chronic inflammatory disease characterized by the destruction of articular cartilage and bone in a chronic phase. Pathology of rheumatoid arthritis suggests autoimmunity linked to inflammation. In our study, rheumatoid arthritis was induced in Wistar rats by intradermal injections of 100 μl of emulsion containing bovine type II collagen in complete Freund's adjuvant at the base of the tail. Disease developed about 13 ± 1 days after immunization and treatment with hesperidin (HES) at a dose of 160 mg kg(-1) body weight was given after onset of disease daily until 20th day. The effect of treatment in the rats was monitored by clinical scoring, biochemical parameters and histological evaluations in joints. A steady increase in the articular elastase, nitric oxide and lipid peroxidation was observed in joints of arthritic rats as compared to control, whereas a significant decrease in reduced glutathione, superoxide dismutase activity and catalase was observed in collagen-induced arthritis rats as compared to control group. The results from the present work indicate that the treatment with hesperidin was effective in bringing about significant changes on all the parameters studied in collagen-induced arthritis rats. These data confirm that erosive destruction of the joint cartilage in collagen-induced arthritis is due free radicals released by activated neutrophils and produced by other biochemical pathways. In the present study, an attempt has been made to amelioration of the disease process by a natural product. These results suggest that oral administration of HES could be effective for treating human RA patients.