A novel melanin complex displayed the affinity to HepG2 cell membrane and nucleus

Area of Science:

• Biomaterials Science
• Pharmaceutical Sciences
• Cancer Research

Background:

• Natural melanin from Catharsius molossus L. exhibits excellent pharmaceutical excipient properties.
• There is a need for water-soluble, protein-free natural melanin sources for pharmaceutical applications.

Purpose of the Study:

• To enzymatically hydrolyze chitosan-melanin complex into chitooligosaccharide-melanin complex (CMC).
• To characterize CMC's structure, self-assembly into nanoparticles (CMC Nps), and its potential for cancer cell targeting.

Main Methods:

• Enzymatic hydrolysis of chitosan-melanin complex.
• Characterization of CMC structure and nanoparticle formation (40 nm).
• In vitro assessment of CMC Nps' interaction with tumor cell membranes and intracellular targeting.

Main Results:

• CMC was successfully synthesized, composed of eumelanin and chitooligosaccharides with a three-layer structure.
• CMC self-assembled into 40 nm nanoparticles in a weakly acidic solution.
• CMC Nps demonstrated strong affinity for tumor cell membranes and effectively entered cells, targeting the nucleus to disrupt proliferation and apoptosis.

Conclusions:

• CMC is a novel biomacromolecule with potential as a water-soluble, protein-free melanin source.
• CMC nanoparticles show promise for targeted delivery to cancer cell nuclei.
• This research suggests CMC as a potential novel material for subcellular organelle targeting in cancer therapy.