Identification of peptide coatings that enhance diffusive transport of nanoparticles through the tumor microenvironment

Rashmi Mohanty; Xinquan Liu; Jae You Kim; Xiujuan Peng; Sahil Bhandari; Jasmim Leal; Dhivya Arasappan; Dennis C. Wylie; Tony Dong; Debadyuti Ghosh

The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. . https://doi.org/10.1101/659524 doi: bioRxiv preprint A peptide-presenting T7 phage library, which was previously developed in our lab, was used to screen and select peptide-presenting phage that permeate through the ECM. The library is a collection of phage presenting cysteine-constrained random 7-mer peptides (denoted as CX7C) on the surface of the T7 gp10 capsid. We screened the phage library against the in vitro tumor ECM using a transwell assay. Tumor-like ECM (thickness ~1 mm) was prepared in the insert of a 3.0 µm pore size polyester membrane 24-well transwell (Corning). Approximately 3.2×10 8 plaque forming units (i.e. amount of phage) of the phage library was added at the top of the tumor ECM in the donor chamber. To allow sufficient time for phage to enter ECM prior to measuring diffusivity, a time lag of 15 minutes was allotted based on theoretical calculations for phage to achieve unhindered diffusion through saline. After, the insert was transferred to a new receiving chamber filled with 600 µL of 1× PBS to maintain the hydrostatic pressure needed for diffusivity.