(M-490) Targeted Delivery System to Endometrial Stromal Cells Using CD-10 Modified Lipid Coated-Mesoporous Silica Nanoparticles

Introduction:: Endometrial cancer has had an unprecedented rise in incidence since 2005, while breast and ovarian cancers are on the decline. The sharp increase in endometrial cancer occurrence is due in part to a surge in obesity-associated endometrial cancer. Recent data shows changes that occur in the endometrial extracellular matrix (ECM) of cancer patients with obesity alters oncogenic development (Lin et al). These findings provide an intriguing possibility to target endometrial cells for delivery of therapeutic drugs that can modulate the obesity-driven oncogenic transformation. The goal of this study is to evaluate the uptake efficiency in endometrial stromal cells, of a mesoporous silica nanoparticle coated with a lipid bilayer (protocells), modified with a CD10 antibody. CD10 is a membrane-bound enzyme found on select cancer and normal bodily cells that utilizes zinc to cleave and inactivate peptides and cytokines. Stromal cells of the endometrium are one such type of cell known to produce CD10 both naturally and also in endometrial cancer.

Materials and Methods:: Fluorescently labeled mesoporous silica nanoparticles (MSNPs) were synthesized via a solution-based surfactant-directed self-assembly method. Liposomes were fused to MSNPs through electrostatic interactions. A CD10 antibody was conjugated to protocells using a biotin-neutravidin interaction. Protocell fluorescence labeling was used to quantitatively assess cellular uptake. Human endometrial stromal cells were treated with CD10-protocells and unmodified protocells in order to assess uptake at different time points. Additionally, co-culture spheroids of human stromal and epithelial cells were formed using low attachment plates to evaluate uptake in a 3D relevant endometrial environment. To test uptake of protocells in the uterus, mice uterus was isolated and treated ex vivo with targeted and untargeted protocells. Protocell fluorescence labeling was used to quantitatively assess cellular uptake using a plate reader, confocal microscope, and an optical live imaging system.

Results, Conclusions, and Discussions:: Analysis of the data from the two-dimensional studies revealed a difference in protocell uptake between targeted and untargeted protocells. The wells that received the treatment of CD10 modified protocells generally produced a higher fluorescence value, indicating a larger presence of protocells within the cells. Other observed patterns within the data also suggest that peak absorption occurs near the 4-hour time mark and will steadily decrease as time continues for both CD-10 protocells and untargeted protocells. Spheroids of ~300 μM were successfully formed after 7 days of culture in low attachment plates, with stromal cells surrounding epithelial cells. Preliminary confocal microscopy images suggest uptake of CD-10 protocells in stromal cells. Optical images of endometrium after ex-vivo treatment of targeted and untargeted protocells demonstrated more fluorescence presence in the uterus treated with CD-10-protocells.

Endometrial cancer is on a path to becoming one of the more prevalent health conditions affecting women in the modern era. Two-dimensional endometrial stromal cell culture studies suggest that the presence of a CD10 antibody leads to greater protocell uptake in stromal cells. Three-dimensional co-culture spheroid models were successfully formed and can be used to assess protocell targeted delivery in a more relevant environment. Finally, we were able to demonstrate the feasibility to deliver nanoparticles into the mouse endometrium ex vivo, using protocells conjugated with the endometrial stromal cell marker CD10 antibody.

Acknowledgements (Optional): : This research was supported, in part, by the National Science Foundation (ECC-1852560).

References (Optional): : Lin, L. L., Kost, E. R., Lin, C. L., Valente, P., Wang, C. M., Kolonin, M. G., Daquinag, A. C., Tan, X., Lucio, N., Hung, C. N., Wang, C. P., Kirma, N. B., & Huang, T. H. (2020). PAI-1-Dependent Inactivation of SMAD4-Modulated Junction and Adhesion Complex in Obese Endometrial Cancer. Cell reports, 33(2), 108253. https://doi.org/10.1016/j.celrep.2020.108253