Building and behavior of a pH-stimuli responsive chitosan nanoparticles loaded with folic acid conjugated gemcitabine silver colloids in MDA-MB-453 metastatic breast cancer cell line and pharmacokinetics in rats.

The pH-stimuli release behavior of nanoformulations may enhance the success rate of chemotherapeutic drugs in cancers by site-specific delivery of drugs to cancer tissues. The aim of the present study was to prepare chitosan (CS) nanoparticles (NPs) with previously synthesized folic acid (FA) capped silver nanoparticles (AgNPs) loaded with the anti-cancer drug gemcitabine (GEM) (FA-GEM-AgNPs). The CS-FA-GEM-AgNPs (CS-NPs) were characterized with dynamic light scattering (DLS), transmission electron microscopy (TEM), energy dispersive x-ray analysis (EDAX), selected area electron diffraction (SAED), and differential scanning calorimetric (DSC) analyses. The in-vitro drug release of GEM was evaluated in media of different pH. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was carried out to determine the cytotoxic effects of the prepared nanoformulations in media with various pH. The time- and pH-dependent apoptotic cell death induced by CS-NPs with MDA-MB-453 human breast cancer cell line was observed using acridine orange (AO)/ethidium bromide (EtBr) staining. The pharmacokinetic parameters were studied with high-performance liquid chromatography (HPLC) and atomic absorption spectroscopy (AAS). Two batches of CS-NPs formulations were prepared, one with AgNPs of particle size 143 nm and the other with 244 nm. The particle size for CS-NPs-I (FA-GEM-AgNPs-143 nm) and CS-NPs-II (FA-GEM-AgNPs-244 nm) was found to be 425 and 545 nm, respectively. The zeta potential was found to be 36.1 and 37.5 mV for CS-NPs-I and CS-NPs-II, respectively. CS-NPs-I and CS-NPs-II showed a polydispersity index (PDI) of 0.240 and 0.261, respectively. A TEM study confirmed the spherical nature of the NPs. The nanoformulations exerted pH-dependant effect against MDA-MB-453 cells with relatively higher cytotoxicity at the lower pH than at higher pH levels. The pharmacokinetic profile and tissue distribution of CS-NPs in rats exerted drug release in a pH-dependent manner with enhanced excretion of Ag+. An optimized nanoformulation for pH-stimuli responsive release of GEM was successfully developed for future therapeutic exploration.

Cytotoxicity and Synergistic Effect of Biogenically Synthesized Ternary Therapeutic Nano Conjugates Comprising Plant Active Principle, Silver and Anticancer Drug on MDA-MB-453 Breast Cancer Cell Line.

Drug delivery through biogenically synthesized silver nanoparticles (AgNPs) in cancer treatment is exerted by smaller size entailing high surface area and synergistic effects of embedded biomolecules.  In this study, prepared ternary conjugates of silver with plant active compound and anticancer drug towards reducing the dose through synergy, rendered by Electrostatic Attraction (EA) of functionalized drug on to the surface of biogenically synthesized AgNPs. The biogenic synthesis resulted in particles of nanometer range as well as serving reducing and capping agents. The cytotoxicity and synergistic effect of ternary therapeutic nano conjugates evaluated using MDA-MB-453 breast cancer cells were found to be superior than Doxorubicin (Dox). Quantitative HPTLC analysis showed 57.22 % inhibition by Dox-AP-AgNPs at a concentration of 2.5 µg/mL of Andrographolide and 0.95 µg/mL of Dox validating synergistic effect of the ternary conjugate.

Synthesis and Characterization of Folic Acid Conjugated Gemcitabine Tethered Silver Nanoparticles (FA-GEM-AgNPs) for Targeted Delivery.

BACKGROUND: Silver nanoparticles (AgNPs) have attracted considerable interest in the medical industry due to their physicochemical properties, small size, and surface plasmon behavior. Their smaller particle size and instability in blood circulation leads to toxicity due to its aggregation as Ag+ ions and accumulation at the deepseated organ. In the present study, we aimed at reducing the toxicity of AgNPs by conjugation with an anticancer drug GEM and to improve their internalization through folate receptors-mediated endocytosis by capping the nanoparticles with folic acid (FA). METHODS: One-pot facile synthesis of FA capped silver nanoparticles (FA-AgNPs) has been achieved by using FA as a reducing agent. FA-AgNPs were mixed with Gemcitabine (GEM) to obtain tethered FA-GEM-AgNPs. Nanoparticles were characterized by Dynamic Light Scattering (DLS), UV-Visible spectroscopy, Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Analysis (EDAX), Selected Area Electron Diffraction (SAED), and Atomic Absorption Spectroscopy (AAS). The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was carried out to determine the cytotoxic effect of the prepared nanoformulations. The apoptotic cell death induced by FA-GEM-AgNPs in breast cancer cells were monitored with Acridine orange (AO)/Ethidium Bromide (EtBr) staining. CONCLUSION: Compared to GEM and AgNPs, FA-GEM-AgNPs showed enhanced cytotoxic effect and internalization in MDA-MB-453 breast cancer cell line. FA-GEM-AgNPs could be an ideal candidate for targeting cancer cells via folate receptor-mediated endocytosis.