Peptide-Functionalized Polymeric Nanoparticles for Delivery of Curcumin to Cancer Cells

Polymeric nanoparticles (NPs) have garnered significant interest due to their potential in drug delivery. Specifically, nanopolymers functionalized with molecules such as proteins or peptides serve as versatile vehicles for this purpose. Curcumin (Cur) is a widely studied anticancer compound known for its positive effects on human health. Nevertheless, its insolubility and low bio-distribution hinder the exploitation of its beneficial traits. In this study, our team developed a nanodelivery system using a nanopolymer called poly(ε-caprolactone)-poly(ethylene glycol) (PCL-PEG), functionalized with A6 peptide to enable targeted delivery of Cur. The designed system exhibited favorable characteristics, including a stable zeta potential of -13.8 mV, a small size of 76.4 nm, uniform surface morphology, and high hydrophilicity with a contact angle of 31.53°. Additionally, the targeted delivery system demonstrated high encapsulation efficiency (EE%) (93 ± 0.89%), drug loading (DL%) (16.7 ± 0.9%), and a slow and gradual release profile with a release of approximately 83.1 ± 0.12%. The MTT assay results showed significant cell death in MDA-MB-231 cancer cells (IC50 = 21.3 ± 1.57 µM) when treated with the Cur-NPs-A6 formulation, while the toxicity of the designed NPs was reduced on non-cancerous MCF-10A cells. Moreover, both the RT-qPCR and invasion assays demonstrated the system's effectiveness in activating apoptosis pathways and inhibiting cell invasion. These findings suggest that the engineered intelligent delivery system, equipped with the A6 peptide, which has a strong affinity for CD44 (a protein with increased expression in malignancy), could be an exceptionally effective strategy for cancer treatment.