Abstract 2065: Anti-FSHR antibody Fab’ fragment conjugated immunoliposomes loaded with cyclodextrin-paclitaxel complex for improved in vitro efficacy on ovarian cancer cells

Abstract

Abstract Purpose of the study was to prepare and characterize cyclodextrin-paclitaxel (CD-PTX) complex encapsulated immunoliposomes (ILs) conjugated with Fab’ fragment of anti-FSHR antibody and to determine their in vitro efficacy for cellular uptake, cytotoxicity, anti-metastatic activity and cell apoptosis on ovarian cancer (OC) cells. CD-PTX complex was formulated using Heptakis(2,6-di-O-methyl)-beta-cyclodextrin (DMBCD) to improve aqueous solubility and liposomal loading of PTX. The complex was encapsulated in PEGylated liposomes (PLs) using reverse phase evaporation technique. ILs were prepared by covalent conjugation of Fab’ fragments of anti-FSHR antibody to functionalized PLs via thioether linkage which was confirmed by SDS-PAGE analysis. The ILs were characterized for size, zeta potential, entrapment, loading efficiency and in vitro drug release profile. ILs were also evaluated for uptake efficiency and in vitro cytotoxicity in FSHR-expressing Caov-3 OC cells. To establish anti-metastatic effect, the ILs, PLs and equal amounts of PTX solution were studied on Caov-3 cells by in vitro wound scratch assay. The effect of PTX solution, PLs and ILs on Caov-3 cell apoptosis and cell cycle was examined using FACS technique. Increased aqueous solubility of 11 mg/ml was achieved for PTX using DMBCD at molar ratio of 20 and the cytotoxic properties of CD-PTX complex was also retained similar to PTX as studied in Caov-3 cells. The PLs and ILs were found to be nanosized with optimum entrapment and improved loading efficiency of PTX. The in vitro release profiles exhibited controlled release of PTX from PLs (21.235±0.423%) and ILs (18.219±0.603%) after completion of 48 h. The IC50 values from MTT assay suggested that ILs was 3.7 and 8.1 times more cytotoxic than PLs and PTX solution respectively for Caov-3 cells after 24 h period. The ILs showed more anti-migration effect and less covered wound (39.66±5.2%) at a concentration of 3nM as compared with PTX solution (70.45±7.12%) and PLs (61.38±4.41%). After 24 h treatment no major distinction in% apoptosis was observed between PTX solution, PLs and ILs. However, after 48 h treatment, PLs and ILs respectively showed about 5.36% and 9.12% higher apoptosis when compared to PTX solution. In Caov-3 cells, after 48 h the ILs at 3nM concentration showed increased G2 phase cell arrest as compared to PLs which indicates the superiority of ILs. To conclude, ILs displayed improved intracellular uptake and enhanced cytotoxic as well as anti-metastatic effects compared to PTX solution and PLs in OC cells. The results clearly highlight the importance of FSHR as one of the prominent targets for OC therapy and also the potential of anti-FSHR Ab Fab’ conjugated nanocarriers to reduce the limitations associated with OC chemotherapy. Citation Format: Priyanka Bhatt, Rohan Lalani, Rajashree Mashru, Ambikanandan Misra. Anti-FSHR antibody Fab’ fragment conjugated immunoliposomes loaded with cyclodextrin-paclitaxel complex for improved in vitro efficacy on ovarian cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2065.