Evaluation of polymeric-based nanoparticles of oncolytic measles virus (OMV) for the treatment of cancer

Abstract

Oncolytic viruses are reported as a powerful tool against cancer nowadays. The novel sustained/controlled and active targeted viral delivery system with the outermost ligand coating for surface-functionalization by encapsulating weak attenuated measles vaccine strain (Edmonston) prepared by ionic gelation method, optimized and characterized. In silico studies confirmed the high affinity of hyaluronic acid (HA) with the CD44 receptors in Prostate Cancer (PC). CD44 high expression was confirmed in prostatic adenocarcinoma (PRAD) by GEPIA and in PC3 cells by Human Atlas. STRING analysis showed all connections of CD44 with cancer metastasis and progression. Bioinformatics tools confirmed the viral hemagglutinin capsid protein interaction with human Caspase-I, TNF-α and NLRP3. NFs with nanosize, spherical, and non-crystalline mucoadhesive characters are selectively attached to CD44. It protects the virus from antibody-mediated clearance and successfully enters the cell by receptor-mediated endocytosis. The encapsulated virus titer 2.34 x 107 TCID50/ml units in NFs showed syncytia formation on post-day infection seven and apoptotic cell death observed after 72 h via MTT assay. Various multiplicities of HA coated OMV-loaded NFs infection compared to MV vaccine on PC3 cells showed IC50 of 5.1 and 3.52 mg/ml, respectively. The virus release was sustained but continuous till 48 h, followed by Higuchi kinetics in an acidic medium. The anticancer potential of OMV-NFs proved with a significant reduction in tumor volume of PC3-induced PC xenograft in the immunosuppressed rat model with recovered body weight. Antioxidant enzymes were reduced and scrutinized the complete blood profile. Histopathology showed less malignancy with angiogenesis and less metastasis to vital organs with desired on-target pharmacological effect. ELISA showed high expression of apoptotic biomarkers Bax, xv cleaved Caspase 3, and cleaved PARP and reduced BCL-2. At the same time, Immunohistochemistry and ELISA confirmed the predicted reduction of Caspase-I, TNF α and NLRP3 in the virus-based NFs treatment group. The microtubule inhibitor Vincristine (VC) NFs were also prepared and characterized. Its drug loading and encapsulation efficiencies were 41.4 and 87%, respectively, followed by Higuchi model. The anticancer activity at doses of 10 to 90 µg/ml on normal prostate epithelial cells (HPrEC) with IC50 of 16.2 µg/ml and cancerous prostate cells (PC3) with IC50 of 32 µg/ml in comparison to raw VC confirmed the strong cytotoxic potential by an MTT assay. The simulation by ADMET Predictor showed the improved physiochemical and pharmacokinetics of VC–NFs at 1 mg/kg via IV route. Then HPLC study confirmed it using plasma samples from healthy rats with an improved encapsulation efficiency of 81.5% and 90% by direct and indirect methods. We evaluated the anticancer potential in the immunosuppressed xenograft rat PC model. Physical observations, biochemical and antioxidant levels, histopathology, Immunochemistry, and ELISA analysis for predicted apoptotic biomarkers to pure VC confirmed it. Thus, prepared virus and chemotherapeutic drug-encapsulated NFs were comparatively potent, efficacious, targeted and safe with lesser off-target toxicities. It has an improved pharmacokinetics bioavailability profile compared to pure vaccine and pure drug. These would be potential targeted therapeutic moieties for cancer treatment in future.