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Published on: November 9, 2016
Non-toxic agarose/gelatin-based microencapsulation system containing gallic acid for antifungal application
P-L Lam1, R Gambari2, S H-L Kok3
1State Key Laboratory of Chirosciences, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, SAR, P.R. China.
Abstract:
Aspergillus niger (A. niger) is a common species of Aspergillus molds. Cutaneous aspergillosis usually occurs in skin sites near intravenous injection and approximately 6% of cutaneous aspergillosis cases which do not involve burn or HIV-infected patients are caused by A. niger. Biomaterials and biopharmaceuticals produced from microparticle-based drug delivery systems have received much attention as microencapsulated drugs offer an improvement in therapeutic efficacy due to better human absorption. The frequently used crosslinker, glutaraldehyde, in gelatin-based microencapsulation systems is considered harmful to human beings. In order to tackle the potential risks, agarose has become an alternative polymer to be used with gelatin as wall matrix materials of microcapsules. In the present study, we report the eco-friendly use of an agarose/gelatin-based microencapsulation system to enhance the antifungal activity of gallic acid and reduce its potential cytotoxic effects towards human skin keratinocytes. We used optimal parameter combinations, such as an agarose/gelatin ratio of 1:1, a polymer/oil ratio of 1:60, a surfactant volume of 1% w/w and a stirring speed of 900 rpm. The minimum inhibitory concentration of microencapsulated gallic acid (62.5 µg/ml) was significantly improved when compared with that of the original drug (>750 µg/ml). The anti-A. niger activity of gallic acid -containing microcapsules was much stronger than that of the original drug. Following 48 h of treatment, skin cell survival was approximately 90% with agarose/gelatin microcapsules containing gallic acid, whereas cell viability was only 25-35% with free gallic acid. Our results demonstrate that agarose/gelatin-based microcapsules containing gallic acid may prove to be helpful in the treatment of A. niger-induced skin infections near intravenous injection sites.
Insights
This study developed an eco-friendly agarose/gelatin microencapsulation system for gallic acid. The new system enhanced antifungal activity against Aspergillus niger and reduced cytotoxicity to skin cells, offering a safer treatment for skin infections.
Area of Science:
- Biomaterials Science
- Mycology
- Dermatology
Background:
- * Aspergillus niger (A. niger) is a common mold causing cutaneous aspergillosis, particularly near intravenous injection sites.
- * Microparticle-based drug delivery systems enhance therapeutic efficacy, but traditional crosslinkers like glutaraldehyde pose risks.
- * Agarose offers an eco-friendly alternative to glutaraldehyde for gelatin-based microencapsulation.
Purpose of the Study:
- * To develop and evaluate an eco-friendly agarose/gelatin microencapsulation system for gallic acid.
- * To enhance the antifungal activity of gallic acid against A. niger.
- * To reduce the potential cytotoxic effects of gallic acid on human skin keratinocytes.
Main Methods:
- * Optimized an agarose/gelatin microencapsulation system using specific ratios (1:1), polymer/oil ratio (1:60), surfactant volume (1% w/w), and stirring speed (900 rpm).
- * Assessed the minimum inhibitory concentration (MIC) of microencapsulated gallic acid against A. niger.
- * Evaluated the cytotoxicity of microencapsulated gallic acid compared to free gallic acid on human skin keratinocytes.
Main Results:
- * Microencapsulated gallic acid showed significantly improved antifungal activity, with an MIC of 62.5 µg/ml compared to >750 µg/ml for the original drug.
- * Agarose/gelatin microcapsules containing gallic acid demonstrated much stronger anti-A. niger activity than free gallic acid.
- * Skin cell viability was approximately 90% with microencapsulated gallic acid, versus 25-35% with free gallic acid after 48 hours.
Conclusions:
- * The agarose/gelatin microencapsulation system effectively enhances gallic acid's antifungal properties against A. niger.
- * This system significantly reduces gallic acid's cytotoxicity to skin cells, improving safety.
- * Agarose/gelatin microencapsulated gallic acid shows promise for treating A. niger-induced skin infections.
