Synthesis and characterization of piroxicam and M (M = Pd(II), Ag(I)) complex nanoconjugates with orange quantum dots for enhanced antimicrobial and anticancer activity

Conjugation and loading of piroxicam and its metal complexes; Palladium(II) (<b>PdL₂</b>) and Silver(I) (<b>AgL</b>) synthesized and characterized by different techniques including infrared, UV-Vis spectroscopy, spectrofluorimetry, transmission electron microscope, x-ray powder diffraction and Zeta potential analyses were achieved. Orange quantum dots (OQDs) nanoparticle showed good stability, encapsulation and loading efficiency and controlled release of loaded piroxicam and its metal complexes. Generally, new OQQs conjugates showed enhanced antimicrobial and anticancer activity.<i>In vitro</i>antimicrobial activity screening demonstrated that<b>Ag</b>(I)-OQDs conjugate displayed potent antibacterial effect that was 1.8-fold against<i>E. coli</i>higher than piroxicam (MIC = 31.85<i>µ</i>M), where<b>Pd</b>(II)-OQDs conjugate depicted the highest activity with MIC of 33.05<i>µ</i>M against<i>P. aeruginosa</i>. In case of G + ve bacteria,<b>Ag</b>conjugate had potent activity which was 2.3-fold on<i>S. aureus</i>higher than piroxicam (MIC = 43.12<i>µ</i>M), while<b>Pd</b>conjugate exerted promising activity that was 3.5-fold against<i>E. faecalis</i>higher than piroxicam (MIC = 74.57<i>µ</i>M).<b>Ag</b>conjugate showed the most promising antifungal activity with 2.5-folds more than piroxicam. The<i>in vitro</i>antiproliferative activity depicted that all synthesized conjugates showed better Cytotoxic effect than piroxicam, specifically<b>Pd</b>conjugate which had IC50 values with by 2-fold lower than piroxicam on human liver cancer cell line<i>Hepg2.</i>While<b>Pd</b>and<b>Ag</b>conjugates showed 2.3 and 1.9-fold higher effect on human colon cancer cell line<b>HT-29</b>compared to piroxicam.