Synthesis of Heteroatom-Doped Polymer-Coated Nanomaterials for Slow and Controlled Drug Release in the Physiological Microenvironment

This study aimed to develop doped carbon dots and coat them with carboxyl-polymer to explore their applications in imaging living tissue cells and achieving targeted drug release, particularly for tumor therapy. The synthesis of NP-CDs involved a one-pot hydrothermal reaction of seaweed powder, ethylene diamine, and phosphoric acid at atmospheric pressure. Subsequently, the NP-CDs were coated with carboxyl-mounted PEG to create PEG@NP-CDs, serving as a nano carrier for delivering the anti-cancer drug Doxorubicin (DOX). The drug delivery capabilities of PEG@NP-CDs were assessed, and their sensitivity to variations in pH value was studied. The hydrothermal reaction successfully yielded NP-CDs with distinctive fluorescence properties, exhibiting green fluorescence at 430 nm and varying emission peaks depending on the excitation wavelength used. The subsequent coating of NP-CDs with carboxyl-mounted PEG resulted in PEG@NP-CDs, which demonstrated biocompatibility and potential for drug delivery applications. The MTT assay confirmed the high biocompatibility of PEG@NP-CDs, rendering them suitable for biomedical applications. The study successfully developed a straightforward method to synthesize CDs doped with nitrogen and phosphorus, which exhibited green fluorescence and sensitivity to excitation wavelengths. These nanomaterials have potential for imaging living tissue cells and achieving slow drug release. Their drug delivery capabilities, especially pH sensitivity, make them promising for targeted therapy, particularly in tumors. The biocompatibility of PEG@NP-CDs further supports their safe biomedical use. Overall, PEG@NP-CDs offer a valuable tool for simultaneous imaging and drug delivery, with promising applications in tumor detection and therapy.