Antimicrobial NIR-Responsive Hydrogels Based on Gellan Gum and Bis-MPA Polyester Dendrimers

Area of Science:

• Biomaterials Science
• Nanotechnology
• Wound Healing

Background:

• Developing advanced wound dressings is crucial for managing infected skin wounds.
• Antimicrobial agents and stimuli-responsive materials offer potential for improved therapeutic outcomes.
• Gellan Gum (GG) and polydopamine (pDA) are explored for their synergistic properties in biomaterial applications.

Purpose of the Study:

• To develop a near-infrared (NIR)-responsive hydrogel for infected wound treatment.
• To incorporate antimicrobial dendrimers and polydopamine into a Gellan Gum-based hydrogel.
• To evaluate the antimicrobial activity, photothermal properties, and biocompatibility of the developed hydrogel system.

Main Methods:

• Ethylenediamine (EDA)-functionalized Gellan Gum was used to create a hydrogel matrix.
• Polydopamine (pDA) was synthesized in situ within the hydrogel, and antimicrobial bis-MPA polyester dendrimers (TMP-G1-[Cys]6 and MP-G2-[Cys]12) were loaded.
• The hydrogel's radical scavenging, photothermal conversion (at 810 nm), dendrimer retention, antimicrobial efficacy against Pseudomonas aeruginosa and Staphylococcus aureus, and cytotoxicity were assessed.

Main Results:

• The GG-EDA@pDA hydrogel exhibited NIR-responsive photothermal properties and radical scavenging activity.
• Dendrimer retention within the hydrogel varied based on molecular weight and charge, influencing antimicrobial efficacy.
• The NIR-induced photothermal effect significantly enhanced the antimicrobial activity of the hydrogel loaded with the most retained dendrimer.
• The developed hydrogels demonstrated excellent physiological fluid absorption, resistance to degradation, and low cytotoxicity to human skin cells (FD-MSCs and HaCaT).

Conclusions:

• The developed NIR-responsive hydrogel loaded with antimicrobial dendrimers is a promising candidate for infected skin wound treatment.
• The combination of photothermal properties and dendrimer delivery offers a synergistic approach to combat bacterial infections.
• The material's properties support its potential application in advanced wound exudate management and reduced dressing change frequency.