Princeton University Library Catalog

Fabrication of Protein Scaffold-Nanoparticle Conjugates for Targeted Cancer Therapeutics

Edelstein, Jasmine [Browse]
Senior thesis
Prud'homme, Robert K. [Browse]
Princeton University. Department of Chemical and Biological Engineering [Browse]
Class year:
60 pages
Summary note:
Targeted nanotherapeutics for cancer aim to preferentially deliver medicine to the tumor, increasing drug localization and reducing negative side effects. In this study, PSb- PEG nanoparticles were specifically targeted to epidermal growth factor receptors (EGFR), often overexpressed in cancer, using protein scaffold ligands known as Centyrins. Both maleimide-thiol and azide-alkyne conjugation chemistries were evaluated. Gel image analysis indicated similar conjugation efficiencies, but azide-alkyne chemistry is preferable for scale-up because it involves one less synthesis step, resists degradation over time, and requires less excess Centyrin to achieve high conjugation efficiency. Based on surface plasmon resonance, Centyrin-conjugated nanoparticles had 17-fold greater avidity for EGFR than free Centyrin at the highest tested ligand density. Fluorescence-activated cell sorting indicated that intracellular uptake plateaus at 1.9 mol% ligand density, reinforcing the literature observation that excessive binding can inhibit endocytosis. In an effort to transition to a biodegradable construct, PS-b-PEG was replaced with PLA-b-PEG. Experiments were conducted to determine the Flash NanoPrecipitation formulation that produces nanoparticles with properties desirable in a cancer nanotherapeutic, namely a diameter between 70 and 90 nm with a size distribution less than 0.2. Three parameters were varied: block copolymer-to-core ratio, solute concentration, and PLA block length. Based on experimental results, MODDE software generated a model to predict hydrodynamic diameter (R\(^{2}\) = 0.58) and size distribution (R\(^{2}\) = 0.81). The predicted optimal formulation was tested and yielded a nanoparticle with a diameter of 97 ± 16 nm and size distribution of 0.2 ± 0.03.