Design and Characterization of a Bioinspired PAMAM@Poly(Caffeic Acid) Magnetite Nanocarrier for Curcumin Delivery

Efficient intracellular drug delivery requires well-designed nanocarriers capable of stabilizing and releasing bioactive compounds in a controlled manner. Here, we introduce a bioinspired nanohybrid system that integrates generation 4.0 poly(amidoamine) (PAMAM) dendrimers with poly(caffeic acid)-coated magnetite nanoparticles (PCA@Fe3O4) to achieve efficient, long-lasting delivery of curcumin. Encapsulation within the PAMAM–PCA@Fe3O4 framework markedly improves curcumin stability and supports controlled release, with a total loading of approximately 190 μg of curcumin per sample as quantified by UV–Vis spectroscopy at 429 nm. AFM measurements showed progressive size increases from ∼26 nm for bare Fe3O4 to ∼43 nm for PCA@Fe3O4 and ∼66 nm for PAMAM–PCA@Fe3O4, while TEM analyses confirmed the spherical morphology of the nanoparticles. Release studies in PBS (pH 7.4, 37 °C) demonstrated a gradual and sustained release profile, with ∼33% of the encapsulated curcumin (∼64 μg) released over 24 h. In vitro cytotoxicity assays in MRC-5 fibroblasts indicated that PAMAM–PCA@Fe3O4 was biocompatible, whereas curcumin-loaded nanohybrids produced dose-dependent cytotoxicity consistent with curcumin’s known biological activity.