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Preparation and Characterization of Individual and Multi-drug Loaded Physically Entrapped Polymeric Micelles
Published on: August 28, 2015
Azithromycin-loaded linolenic acid-modified methoxy poly(ethylene glycol) micelles for bacterial infection treatment
Yi Wen1, Zhimei Song1, Hongmei Xu1
1School of Biological Science and Technology, University of Jinan, No. 336 West Road of Nanxinzhuang, Jinan, 250022, Shandong Province, People's Republic of China.
Abstract:
In the study, new polymeric micelles loaded with azithromycin were prepared to enhance azithromycin's solubility and evaluate its in vitro/in vivo antibacterial activity against Staphylococcus aureus. Amphiphilic α-Linolenic acid-methoxy poly (ethylene glycol) polymer (MPEG-LNA) was synthesized through DCC-DMAP esterification procedure. Through thin-film hydration method, optimized azithromycin-loaded micelles (AZI-M) were prepared with 87.15% of encapsulation efficiency and 11.07% of drug loading capacity when the ratio of LNA to MPEG was 4. Azithromycin's water-solubility was obviously enhanced due to its loading into the polymeric micelles. The azithromycin-loaded micelles were characterized in terms of x-ray diffraction, Fourier transform infrared spectroscopy, in vitro release, and in vitro/in vivo antibacterial experiments. Although the drug-loaded micelles provided a slow and continuous azithromycin's release in comparison with free azithromycin, in vitro antibacterial activity results confirmed that its effect on the inhibition of bacterial growth and biofilm formation was similar to free azithromycin. It is more interesting that the azithromycin-loaded micelles achieved good in vivo antibacterial therapeutic effect like QiXian® (azithromycin lactobionate injection) in mouse model of intraperitoneal infection. AZI-M can be considered as a potential candidate for in vivo antibiotic therapy of Staphylococcus aureus infections.
Insights
New polymeric micelles effectively enhanced azithromycin solubility and showed promising in vitro and in vivo antibacterial activity against Staphylococcus aureus infections.
Area of Science:
- Pharmaceutical Nanotechnology
- Drug Delivery Systems
- Antimicrobial Research
Background:
- Azithromycin, a widely used antibiotic, suffers from poor water solubility, limiting its therapeutic applications.
- Development of novel drug delivery systems is crucial for improving antibiotic efficacy and overcoming resistance.
- Polymeric micelles offer a promising platform for enhancing the solubility and delivery of hydrophobic drugs.
Purpose of the Study:
- To synthesize and characterize novel polymeric micelles loaded with azithromycin (AZI-M).
- To evaluate the in vitro and in vivo antibacterial activity of AZI-M against Staphylococcus aureus.
- To assess the potential of AZI-M as an improved drug delivery system for azithromycin.
Main Methods:
- Synthesis of amphiphilic MPEG-LNA polymer via DCC-DMAP esterification.
- Preparation of azithromycin-loaded micelles (AZI-M) using the thin-film hydration method.
- Characterization of AZI-M using techniques including XRD, FTIR, and in vitro release studies.
- Evaluation of in vitro antibacterial activity against Staphylococcus aureus, including biofilm inhibition.
- Assessment of in vivo therapeutic efficacy in a mouse model of intraperitoneal infection.
Main Results:
- Optimized AZI-M achieved high encapsulation efficiency (87.15%) and drug loading capacity (11.07%).
- Loading azithromycin into micelles significantly enhanced its water solubility.
- AZI-M demonstrated sustained drug release and comparable in vitro antibacterial activity to free azithromycin.
- In vivo studies showed AZI-M achieved a significant therapeutic effect against Staphylococcus aureus infection in mice.
Conclusions:
- MPEG-LNA based polymeric micelles are effective in enhancing azithromycin solubility and delivery.
- AZI-M exhibits potent in vitro and in vivo antibacterial activity against Staphylococcus aureus.
- AZI-M represents a promising nanocarrier for the treatment of Staphylococcus aureus infections.
