Polyionic Complexed Antibacterial Heparin-Chitosan Particles for Antibiotic Delivery.

Area of Science:

• Biomaterials Science
• Nanotechnology
• Drug Delivery Systems

Background:

• Challenges in antibacterial delivery include poor drug stability and rapid degradation.
• Biocompatible nanocarriers offer sustained release and reduced toxicity.
• Polyhexamethylene biguanide (PHMB) is an effective antibiotic requiring improved delivery methods.

Purpose of the Study:

• To develop and characterize heparin-chitosan nanoparticles for efficient encapsulation and controlled release of PHMB.
• To evaluate the in vitro sustained release profile of PHMB-loaded nanoparticles.
• To assess the cytotoxicity and antibacterial efficacy of the developed nanocarrier system.

Main Methods:

• Tailored polyionic particles were synthesized using ionic interactions between heparin and chitosan.
• Nanoparticle formulations were characterized for size, polydispersity, surface charge (zeta potential), and morphology.
• In vitro drug release studies, cytotoxicity assays with human dermal fibroblasts, and antibacterial evaluations against *Enterococcus faecalis* and *Escherichia coli* were performed.

Main Results:

• A formulation with a four-parts heparin to one-part chitosan ratio successfully encapsulated PHMB, exhibiting a negative zeta potential.
• Sustained in vitro release of PHMB from the nanoparticles was observed over approximately 10 days.
• PHMB-loaded nanoparticles demonstrated significantly reduced toxicity (48% reduction) compared to soluble PHMB and exhibited potent antibacterial activity, including direct bacterial killing.

Conclusions:

• Heparin-chitosan nanoparticles provide an effective platform for the sustained and controlled delivery of PHMB.
• The developed nanocarrier system enhances drug stability, reduces cytotoxicity, and maintains potent antibacterial efficacy.
• This approach holds promise for improving the treatment of bacterial infections at tissue injury sites.