Cellular Uptake of PEGylated Nanoparticles conjugated with Cell Penetrating Peptide

Author: Kaitlyn Dickinson, Department of Biomedical Engineering

Mentor: Dr. Timothy Brenza, Department of Chemical and Biological Engineering

According to the National Cancer Institute, lung and bronchus cancer has accounted for 12.7% of all new cancer cases with a 5-year relative survival rate of 20.5% with our current treatment options. With roughly a 1 out of 5 patient survival, novel drug delivery systems have been investigated that can help increase the efficiency and cargo capacity. PEGylation – a method that conjugates poly(ethylene glycol) to nanoparticles – is one of the only FDA approved techniques to reduce non-specific particle uptake and increase circulation time. However, cell penetrating peptides (CPP) show promise as vehicles for delivering a variety of cargo due to their high target specificity for membrane receptors. Antennapedia (Antp) has been increasingly explored as a potential drug targeting moiety due to its low toxicity and high cellular specificity for enhancing uptake. The peptide has been shown to translocate macromolecules quickly across the cellular membrane making it a potential vector for drug delivery. However, the size limitation of cargo delivery into nonphagocytic cells and multiple surface conjugation have not been studied. The objective of this experiment is to evaluate the cargo size dependence on Antp enhanced uptake with nonphagocytic cell.

Phagocytic and non-phagocytic cell lines were used in these experiments. The human lung epithelial cell line, A549, was used as non-phagocytic cells. The human monocytic cell line, THP-1, differentiated to a macrophage phenotype was used as phagocytic cells. Fluorescently labeled polystyrene nanoparticles of multiple sizes (0.02 µm, 0.2 µm, and 1.0 µm) were conjugated to poly(ethylene glycol), Antp, or both. Conjugated nanoparticles were characterized for size, morphology, and surface charge through Dynamic Light Scattering (DSL) and Scanning Electron Microscopy (SEM). Cellular uptake of the nanoparticles was measured quantitatively through microscopy.