Synthesis of functionalized silk-coated chitosan-gold nanoparticles and microparticles for target-directed delivery of antitumor agents

Chemically modified biopolymers derived nanomaterials have shown great potential in drug delivery and live-cell imaging. We have developed two materials, doxorubicin-loaded chitosan-gold nanoparticles and beads, both embedded with functionalized silk fibroin. Nanoparticles with size 8 +/- 3 nm were synthesized using chitosan as reducing and stabilizing agent. Beads with 900-1000 mu m size were formulated by the ionic gelation technique. Both the materials were coated with functionalized silk fibroin for targeted and sustained drug release properties. The coated materials showed retarded drug release compared to the uncoated ones. The cytotoxicity was assessed in HeLa cell lines, which demonstrated a maximum dose-dependent decrease in cell viability for the cells treated with folate conjugated silk fibroin coated nanoparticles. The live-cell imaging of the nanoparticles unveiled the increased cellular uptake of the coated materials by seven folds than the uncoated ones. Thus, functionalized silk coated materials can be effective drug delivery tools for targeted and sustained drug release.