Medical News Observer

Researchers have used autologous immune cells from the mouse to create nanovesicles to be used in the delivery of drugs to tumors. This technique helped them to create a sufficient number of nanovesicles inexpensively to be used as drug delivery system.

This image shows ligands-grafted extracellular vesicles as drug delivery vehicles. Credit: Xin Zou

Cells naturally release nanovesicles to carry chemical messages between cells. To create targeted nanovesicles, ligands (short pieces of protein) need to be attached to the nanovesicle wall so they can recognize tumor cells. This is done by incorporating DNA into cells and collecting extracellular nanovesicles from cell culture supernatant. However, the yield of nanovesicles is poor using above process. Researchers now developed a new approach by chemically grafting lipid tagged ligands to the cell membrane and then passing them through a seave to create large amounts of fillable and targeted nanovesicles.  Research findings are published in journal Cancer Research.

“Currently, natural nanovesicles can be harvested from cell culture supernatant (the fluid surrounding cultured cells) and they are fillable,” said Yuan Wan, a postdoctoral fellow in biomedical engineering, Penn State. “However, there are two problems using them for cancer treatment. There aren’t enough nanovesicles produced in short timescales and they do not have targeting effect.”

“Pushing the cells through a filter is the engineered way to produce lots of nanovesicles,” said Zheng. “This approach enables us to create nanovesicles with different ligands targeting different types of tumors in about 30 minutes to meet actual needs,” said Zheng. “With this approach, we also can put different types of ligands on a nanovesicle. We could have one ligand that targets while another ligand says, ‘don’t eat me.’”

Reference: Wan, Yuan, Lixue Wang, Chuandong Zhu, Qin Zheng, Guoxiang Wang, Jinlong Tong, Yuan Fang, Yiqiu Xia, Gong Cheng, Xia He, and Si-Yang Zheng. “Aptamer-Conjugated Extracellular Nanovesicles for Targeted Drug Delivery.” Cancer Research 78, no. 3 (2017): 798-808. doi:10.1158/0008-5472.can-17-2880.

Research funding: Nanjing Science and Technology Development Foundation, Jiangsu Provincial Medical Youth Talent Award, Natural Science Foundation of Jiangsu Province, U.S. National Institutes of Health.

Adapted from press release by Penn State.