Silk Cocoon-Derived Protein Bioinspired Gold Nanoparticles as a Formidable Anticancer Agent

Area of Science:

• Biomaterials Science
• Nanotechnology
• Cancer Research

Background:

• Sericin, a natural protein, offers biocompatibility and biodegradability.
• Gold nanoparticles (AuNPs) possess unique optical and electronic properties for biomedical applications.
• Developing novel drug delivery systems for targeted cancer therapy is crucial.

Purpose of the Study:

• To synthesize and characterize bioinspired sericin encapsulated gold nanoparticles (SGNPs).
• To investigate the conformational changes of sericin during SGNP synthesis.
• To evaluate the efficacy and safety of SGNPs against lung cancer cells.

Main Methods:

• Bottom-up synthesis of SGNPs using HAuCl₄ and sericin.
• Circular dichroism (CD) and fluorescence spectroscopy for sericin conformational analysis.
• FTIR, MTT assay, and nuclear fragmentation assay for characterization and efficacy evaluation.

Main Results:

• SGNPs were successfully synthesized, with sericin undergoing conformational changes (unfolding/folding) during the process.
• CD and FTIR confirmed alterations in sericin's secondary structure (α-helix and β-sheet content).
• SGNPs exhibited significant cytotoxicity against A549 lung cancer cells (IC₅₀ = 145.49 µM) with no toxicity to NRK cells.

Conclusions:

• Sericin encapsulation modulates gold nanoparticle properties and induces apoptosis in cancer cells.
• SGNPs effectively induce apoptosis via ROS generation, mitochondrial Cyt-c release, and caspase-3 activation.
• These findings highlight SGNPs as a promising, non-toxic therapeutic agent for lung cancer treatment.