Optimally biosynthesized, PEGylated gold nanoparticles functionalized with quercetin and camptothecin enhance potential anti-inflammatory, anti-cancer and anti-angiogenic activities

BACKGROUND: The development of nano delivery systems is rapidly emerging area of nanotechnology applications where nanomaterials (NMs) are employed to deliver therapeutic agents to specific site in a controlled manner. To accomplish this, green synthesis of NMs is widely explored as an eco-friendly method for the development of smart drug delivery system. In the recent times, use of green synthesized NMs, especially metallic NMs have fascinated the scientific community as they are excellent carriers for drugs. This work demonstrates optimized green, biogenic synthesis of gold nanoparticles (AuNPs) for functionalization with quercetin (QT) and camptothecin (CPT) to enhance potential anti-inflammatory, anti-cancer and anti-angiogenic activities of these drugs. RESULTS: Gold nanoparticles were optimally synthesized in 8 min of reaction at 90 °C, pH 6, using 4 mM of HAuCl(4) and 4:1 ratio of extract: HAuCl(4). Among different capping agents tested, capping of AuNPs with polyethylene glycol 9000 (PG9) was found best suited prior to functionalization. PG9 capped AuNPs were optimally functionalized with QT in 1 h reaction at 70 °C, pH 7, using 1200 ppm of QT and 1:4 ratio of AuNPs-PG9:QT whereas, CPT was best functionalized at RT in 1 h, pH 12, AuNPs-PG9:CPT ratio of 1:1, and 0.5 mM of CPT. QT functionalized AuNPs showed good anti-cancer activity (IC(50) 687.44 µg/mL) against MCF-7 cell line whereas test of anti-inflammatory activity also showed excellent activity (IC(50) 287.177 mg/L). The CAM based assessment of anti-angiogenic activity of CPT functionalized AuNPs demonstrated the inhibition of blood vessel branching confirming the anti-angiogenic effect. CONCLUSIONS: Thus, present study demonstrates that optimally synthesized biogenic AuNPs are best suited for the functionalization with drugs such as QT and CPT. The functionalization of these drugs with biogenic AuNPs enhances the potential anti-inflammatory, anti-cancer and anti-angiogenic activities of these drugs, therefore can be used in biomedical application. [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12951-021-00836-1.