Characterization of Glycoconjugate-Nanoparticle Interfaces on the Cell Surface for Optimized Target Delivery

In target therapy, nanoparticles as vectors offer unique possibilities to overcome barriers and facilitate targeted drug delivery. Feasibility of target delivery of drugs using magnetic nanoparticles (MNPs) under magnetic guiding has been demonstrated to induce local retention of drugs and reduce dosage of drugs in animal models. Nevertheless, how artificially produced nanoparticles may interact with cells remains largely unknown, which could be critical information in designing vector with targeting effects. Since glycoconjugates on the plasma membrane play an important role in virus infection, we intent to test a hypothesis that direct or indirect interaction of nanoparticles with heparan sulfate proteoglycan (HSPG) serves as imperative first steps in nanoparticle internalization. In addition, a nitric oxide (NO)-dependent signaling may enhance endocytosis of nanoparticles. Two models are proposed in the study: 1) positively charged nanoparticles may directly bind to negatively charged heparan sulfate to induce HSPG clustering on the cell surface, which then drives endocytosis of nanoparticles; 2) negatively charged nanoparticles may interact with a ligand for a 67-Kd laminin receptor (67LR) to drive an HSPG- and NO-dependent endocytosis of the nanoparticles. In these studies, glioma cells vs. vascular endothelial cells with relatively high vs. low HSPG expression levels, respectively, will be used for quantitative determination of MNP-cell interaction. Since HSPG forms a barrier layer, i.e., glycocalyx, of endothelium in the lumen of blood vessels, possible interaction of nanoparticles with intact vs. glycocalyx removed endothelial surface will be studied. Our study may promote understanding of nanoparticle-cell interfaces, and establish techniques for manipulation of MNPs in magnetic targeting. Specific aims are proposed:Aim 1: to determine whether HSPG participates in nanoparticle internalization. Aim 2: to determine signaling pathways involved in HSPG-mediated nanoparticle internalization.Aim 3: to determine whether glycoconjugates participate in local retention and endothelial internalization of MNPs in microcirculation.

Project ID:PA10708-1185
External Project ID:MOST107-2311-B182-002