Synthesis of Cholic Acid Derived Thermo and pH Responsive Copolymeric Micelles Encapsulated Gold and Silver Nanoparticle and Their Evaluation of Anticancer Studies

ABSTRACT

In this study, synthesis of cysteamine conjugated poly(NIPAM‐co‐MECA) using cholic acid methacrylate and (N‐isopropyl acrylamide) NIPAM by free radical co‐polymerization has been demonstrated. The structure of the poly(NIPAM‐co‐MECAME) was successfully characterized through FT‐IR, ¹ H NMR, and ¹³ C NMR spectroscopy. The number and weight average molecular weight of the poly(NIPAM‐co‐MECA‐Cys) was determined to be 8060 and 8632 g/mol, respectively, with a PDI value of 1.07 as obtained from gel permeation chromatography (GPC) techniques. The synthesized poly(NIPAM‐co‐MECA‐Cys) exhibit thermo and pH responsive at basic pH. Critical aggregation concentrations (CAC) of poly(NIPAM‐co‐MECA‐Cys) was calculated to be 5.46 × 10 ⁻⁴ and 1.81 × 10 ⁻³  wt%, using pyrene as probe. The prepared polymer acting as both a reducing and stabilizing agent at above the CAC mediated synthesis of Au and Ag NPs under sunlight irradiation, non‐toxic, environmentally friendly and renewable source. The optical and morphological characteristics of NPs were analyzed using UV–Visible, HR‐TEM, DLS, and zeta potential analysis. The mean particle size of the Au and Ag NPs were determined to be 10 ± 2 and 8.2 ± 1.8 nm, respectively. Polymer capped nanoparticles showed concentration‐dependent cytotoxicity and apoptosis against A549 cells at the above CAC wherein AgNPs exhibiting greater anti‐cancer activity and toxicity compared to AuNPs.