Spray-drying-engineered CS/HA-bilayer microneedles enable sequential drug release for wound healing

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Wound Healing Research

Background:

• Chronic wounds present a significant global health challenge due to high incidence and mortality.
• Effective chronic wound healing requires phased delivery of antimicrobial and regenerative agents.
• Existing treatments often struggle with controlled drug release for optimal therapeutic outcomes.

Purpose of the Study:

• To develop a microneedle (MN) patch with a biphasic drug release system for enhanced chronic wound healing.
• To integrate both antibacterial and regenerative functionalities into a single, localized delivery system.
• To investigate the efficacy of staged drug delivery in promoting wound closure and tissue regeneration.

Main Methods:

• Fabrication of a bilayer MN patch using solvent casting and spraying techniques.
• Utilized a copper/PDMS mold to prevent chitosan deformation during drying.
• Loaded hyaluronic acid (HA) coating with doxycycline (DOX) and chitosan (CS) core with vascular endothelial growth factor (VEGF).

Main Results:

• In vitro studies demonstrated rapid release (98.8% in 10 hours) of the coating drug (DOX) and sustained release (up to 70 hours) of the core drug (VEGF).
• In vivo studies on C57 mice showed nearly complete wound healing by day 9 post-treatment with the CS/HA-bilayer MNs.
• Histological analysis revealed reduced inflammation, increased epithelial regeneration, and enhanced collagen deposition in treated wounds.

Conclusions:

• The developed CS/HA-bilayer MN patch effectively achieves phased delivery of antibacterial and regenerative drugs.
• This integrated approach significantly accelerates chronic wound healing by managing infection and promoting tissue repair.
• The MN patch shows promising potential for clinical applications in advanced wound care.