Multifunctional nanocarriers: enhanced doxorubicin release from CQD-tagged SBA-15 silica nanoparticles

The Santa Barbara Amorphous-15 (SBA-15) silica mesoporous nanoparticles (SBANPs) and carbon quantum dots (CQDs) were synthesized and characterized using nitrogen adsorption isotherms, dynamic light scattering, thermal gravimetric analysis, infrared spectroscopy, and X-ray diffraction. The doxorubicin loading capacity of 75.5 mg/g and the loading efficiency of 75% was calculated for the synthesized SBANPs. Theoretical loading mechanism was studied using density functional theory on DOX - SBA-15 and shows that DOX/SBANP loading possess binding energy within the range of chemisorption with the binding energy of -167.12 kJ/mol. The SBANPs were modified with CQDs and folic acid as labelling and targeting agents and capped with PVP for temperature-controlled release. The effect of pH (5.2 and 7.2), temperature (37 and 48 °C), and glutathione concentration were studied as factors affecting the release performance of the carrier. In the pH of the tumor microenvironment and in the presence of glutathione, 50% of the drug was released within 24 h. However, when the temperature was raised to 48 °C, the release increased to 80%. Because of the proven photothermal property of CQDs, this simple and low cost multifunctional nanocarrier can be used for targeted delivery and controlled release in cancer cells.