SU-CCS-1 lipid extract-modified nanoliposomes and characteristic growth profile of a model clear cell sarcoma target cell line

Background: Sarcomas account for approximately 1% of adult cancers and 15% of childhood cancers in the United States. Conventional treatment strategies are somewhat effective during early disease, but once metastasized, treatment success significantly declines. Nanomedicine presents an alternative approach to increase current treatment efficacy and prolong survival. Optimization of liposomal preparations is essential to ensure the most selective targeting. The objective of the study was to develop a novel nanoliposomal drug delivery system using a cellular model of human clear cell sarcoma in vitro. Methods: The SU-CCS-1 cell line was selected as the cellular model for clear cell sarcoma and used for the drug selectivity studies. SU-CCS-1 cells were cultured and expanded in vitro for cellular extraction purposes. Cellular lipid extract (LE) material was derived from a clear cell sarcoma target (SU-CCS-1) cell line. Nanoliposomes were optimized for LE and cholesterol content. DPPE-Rhodamine (used as a fluorescence indicator) for cellular uptake studies, and a fluorescence microplate reader was used to assess relative fluorescence intensity values. Phase I of evaluation included characterization of cells and cellular uptake properties of nanoliposomal preparations of DOPC and cholesterol consisting of 0, 5, and 10 mol% cholesterol content. To characterize the cellular growth characteristics, separate flasks were prepared with either 100% adherent or 100% suspension cells acquired from a mature mixed cell population. The percentage of adherent and suspension cells was determined on Day 0 and Day 5. Results: An evaluation of growth profile characteristics of the SU-CCS-1 target cell line revealed a substantial transformation of suspension cells to adherent cells over time. While the flask of 100% adherent cells remained 72% adherent after 5 days, the flask of 100% suspension cells transformed to become 59% adherent after 5 days. The particle size for nanoliposomes containing 0, 5, and 10 mol% cholesterol was 283 nm, 139.9 nm, and 247 nm, respectively. Additionally, the inclusion of 10 mol% SU-CCS-1-LE increased uptake of nanoliposomes compared to 0% LE control preparations (without SU-CCS-1-LE). Conclusion: Preliminary findings suggest that the DOPC:cholesterol ratio affects nanoliposome uptake by SU-CCS-1 cells. The inclusion of SU-CCS-1-LE in nanoliposomes enhances their targeting efficiency. Ongoing studies will investigate the effect of dual incorporation of optimized cholesterol and SU-CCS-1-LE content on the targeting of clear cell sarcoma.