Encapsulation and controlled release of 1,4-naphthoquinone in PDLA nanoparticles: design, biological efficacy, and cancer targeting

Drug release can be controlled by encapsulating active compounds in polymeric vehicles. Using nanotechnology, pharmaceutical drug delivery systems can be controlled and precise. The aim of this work is to obtain and characterize biocompatible micro and nanoparticulate systems based on a poly(D-lactic acid) matrix (PDLA) to study the controlled release of 1,4-naphthoquinone, which has reported anticancer activity. Scanning electron microscopy revealed spherical particles with an average size of 347 nm and 86% in the nanometer range. The encapsulation efficiency was 98.3%, as assessed by UV-visible spectroscopy. The hydrolytic degradation over 11 weeks showed controlled release of naphthoquinone at different pH conditions: 20.98% in alkaline, 19.69% in physiological, 18.83% in strongly acidic, and 16.70% in slightly acidic conditions. The enhanced release at alkaline pH suggests potential anticancer activity in colorectal cancer, benefiting treatment by releasing the drug to the affected area. Molecular docking studies on COX-2 confirmed these results, showing 1,4-naphthoquinone interacts with key amino acids (ALA202, THR206, HIS207) in the active site, modifying the prostaglandin chain which is crucial for the enzyme's function. The results show that this system has a high potentiality for use for pharmacological applications in colorectal cancer, as 1,4-naphthoquinone exhibits electronic properties.