pH-responsive onion-structured hydrogel beads based on chitosan-spider silk-graphene quantum dots for controlled drug...

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Nanotechnology

Background:

• Cancer therapy faces challenges like poor drug targeting and burst release.
• Chitosan (Cs) and spider silk (SS) are biocompatible polymers with potential in drug delivery.
• Graphene quantum dots (GQDs) offer unique fluorescent properties for tracking.

Purpose of the Study:

• To develop pH-responsive multilayer hydrogel beads for controlled doxorubicin (DOX) delivery.
• To incorporate GQDs for fluorescent tracking and assess antibacterial properties.
• To overcome limitations of conventional cancer therapies through targeted drug release.

Main Methods:

• Hydrogel beads fabricated using chitosan and spider silk, crosslinked with sodium citrate.
• Spider silk extracted preserving beta-sheet structures; GQDs synthesized via pyrolysis.
• In vitro drug release studies at different pH levels (4 and 7).
• SEM analysis for structural characterization; antibacterial assays performed.

Main Results:

• Monolayer beads exhibited pH-dependent swelling, with higher swelling in acidic conditions (550%) vs. basic (90-110%).
• In vitro DOX release showed significant release at pH 4 (84%) compared to pH 7 (21%), indicating tumor targeting.
• Multilayer beads significantly reduced burst release (40%) compared to monolayer beads (80%) in 5 hours.
• Spider silk reinforcement enhanced mechanical strength; beads displayed antibacterial activity.

Conclusions:

• Developed pH-responsive multilayer hydrogel beads using chitosan, spider silk, and GQDs for controlled DOX delivery.
• The hydrogel system demonstrates potential for targeted cancer therapy by releasing drugs in the tumor microenvironment.
• The combination of materials provides enhanced mechanical properties, fluorescence, and antibacterial activity.