Solvent-Free Process for Preparing Metal-Organic Framework Composites Based on Carbon-Based Quantum Dots and Their Derivatives as Drug Delivery Systems for Andrographolide.

Andrographolide (ADG) was conjugated with MIL-53(Al), ZIF-8, carbon-based quantum dots (CBQDs) and doped carbon-based quantum dots (D-CBQDs) using high-pressure (0.3 GPa) contact. This solvent-free approach is environmentally friendly, energy-efficient, and time-saving, resulting in ADG-MOFs-CBQDs/D-CBQDs with physical properties comparable to those produced by traditional liquid phase encapsulation. The resulting nanocomposites were characterized using SEM, XRD, TGA, FT-IR, and H NMR. The results indicate that ADG was partly encapsulated within the metal-organic framework (MOF) pores, while another portion was bound externally to CBQD/D-CBQDs, as evidenced by distinct drug signals in each analysis. This green synthesis approach simplifies the conjugation process. It significantly enhances the drug solubility, as indicated by changes in hydrophobicity observed via H NMR, surpassing the improvements achieved by ADG encapsulation within MOFs alone. Additionally, in preliminary tests, the materials exhibited significant cytotoxicity against PC3 cells compared to ADG (25.05 ± 0.06 µg/mL) after 48 hours of exposure.