Chemotherapeutics-Loaded Poly(Dopamine) Core-Shell Nanoparticles for Breast Cancer Treatment.

Chemophotothermal therapy is an emerging treatment of metastatic and drug-resistant cancer anomalies. Among various photothermal agents tested, poly(dopamine) provides an excellent biocompatible alternative that can be used to develop novel drug delivery carriers for cancer treatment. This study explores the synthesis of starch-encapsulated, poly(dopamine)-coated core-shell nanoparticles in a one-pot synthesis approach and by surfactant-free approach. The nanoparticles produced are embellished with polymeric stealth coatings and are tested for their physiologic stability, photothermal properties, and drug delivery in metastatic triple-negative breast cancer cell (TNBC) lines. Our results indicate that stealth polymer-coated nanoparticles exhibit superior colloidal stability under physiologic conditions, and are excellent photothermal agents, as determined by the increase in temperature of solution in the presence of nanoparticles, upon laser irradiation. The chemotherapeutic drug-loaded nanoparticles also showed concentration-dependent toxicities in TNBC and in a brain metastatic cell line. SIGNIFICANCE STATEMENT: This study develops, for the first time, biocompatible core-shell nanoparticles in a template-free approach that can serve as a drug delivery carrier and as photothermal agents for cancer treatment.

Elucidating the Role of Optical Activity of Polymers in Protein-Polymer Interactions.

Proteins are biomolecules with potential applications in agriculture, food sciences, pharmaceutics, biotechnology, and drug delivery. Interactions of hydrophilic and biocompatible polymers with proteins may impart proteolytic stability, improving the therapeutic effects of biomolecules and also acting as excipients for the prolonged storage of proteins under harsh conditions. The interactions of hydrophilic and stealth polymers such as poly(ethylene glycol), poly(trehalose), and zwitterionic polymers with various proteins are well studied. This study evaluates the molecular interactions of hydrophilic and optically active poly(vitamin B5 analogous methacrylamide) (poly(B5AMA)) with model proteins by fluorescence spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and circular dichroism (CD) spectroscopy analysis. The optically active hydrophilic polymers prepared using chiral monomers of R-(+)- and S-(-)-B5AMA by the photo-iniferter reversible addition fragmentation chain transfer (RAFT) polymerization showed concentration-dependent weak interactions of the polymers with bovine serum albumin and lysozyme proteins. Poly(B5AMA) also exhibited a concentration-dependent protein stabilizing effect at elevated temperatures, and no effect of the stereoisomers of polymers on protein thermal stability was observed. NMR analysis, however, showed poly(B5AMA) stereoisomer-dependent changes in the secondary structure of proteins.