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Updated: May 19, 2026
Evaluation of Antimicrobial Activities of Nanoparticles and Nanostructured Surfaces In Vitro
Published on: April 21, 2023
Gentamicin-loaded nanoparticles show improved antimicrobial effects towards Pseudomonas aeruginosa infection
Sharif M Abdelghany1, Derek J Quinn, Rebecca J Ingram
1School of Pharmacy, Queen's University Belfast, UK.
Abstract:
Gentamicin is an aminoglycoside antibiotic commonly used for treating Pseudomonas infections, but its use is limited by a relatively short half-life. In this investigation, developed a controlled-release gentamicin formulation using poly(lactide-co-glycolide) (PLGA) nanoparticles. We demonstrate that entrapment of the hydrophilic drug into a hydrophobic PLGA polymer can be improved by increasing the pH of the formulation, reducing the hydrophilicity of the drug and thus enhancing entrapment, achieving levels of up to 22.4 μg/mg PLGA. Under standard incubation conditions, these particles exhibited controlled release of gentamicin for up to 16 days. These particles were tested against both planktonic and biofilm cultures of P. aeruginosa PA01 in vitro, as well as in a 96-hour peritoneal murine infection model. In this model, the particles elicited significantly improved antimicrobial effects as determined by lower plasma and peritoneal lavage colony-forming units and corresponding reductions of the surrogate inflammatory indicators interleukin-6 and myeloperoxidase compared to free drug administration by 96 hours. These data highlight that the controlled release of gentamicin may be applicable for treating Pseudomonas infections.
Insights
Researchers developed controlled-release gentamicin nanoparticles using PLGA to improve treatment for Pseudomonas infections. This formulation demonstrated sustained drug release and enhanced antimicrobial efficacy in vitro and in vivo.
Area of Science:
- Biomedical Engineering
- Pharmacology
- Infectious Diseases
Background:
- Gentamicin is an essential aminoglycoside antibiotic for Pseudomonas infections.
- Its clinical utility is constrained by a short half-life, necessitating frequent dosing.
- Developing sustained-release formulations is crucial for improved therapeutic outcomes.
Purpose of the Study:
- To engineer poly(lactide-co-glycolide) (PLGA) nanoparticles for controlled gentamicin release.
- To optimize drug entrapment within the PLGA matrix.
- To evaluate the in vitro and in vivo efficacy of the gentamicin-PLGA nanoparticles against Pseudomonas aeruginosa.
Main Methods:
- Fabrication of PLGA nanoparticles encapsulating gentamicin.
- Optimization of drug entrapment by adjusting formulation pH.
- In vitro drug release studies over 16 days.
- Antimicrobial testing against planktonic and biofilm P. aeruginosa PA01.
- In vivo evaluation in a 96-hour murine peritoneal infection model.
Main Results:
- Achieved high gentamicin entrapment efficiency (up to 22.4 μg/mg PLGA) by increasing formulation pH.
- Demonstrated sustained gentamicin release from PLGA nanoparticles for up to 16 days.
- Showed significantly enhanced antimicrobial activity in vivo, reducing bacterial load and inflammatory markers (interleukin-6, myeloperoxidase) compared to free gentamicin.
Conclusions:
- PLGA nanoparticles provide an effective platform for controlled gentamicin delivery.
- This formulation significantly improves therapeutic efficacy against Pseudomonas infections in a murine model.
- Controlled-release gentamicin holds promise for managing challenging Pseudomonas infections.
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