title: Non-toxic agarose/gelatin-based microencapsulation system containing gallic acid for antifungal application.
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.
authors.affiliation: State Key Laboratory of Chirosciences, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, SAR, P.R. China.
authors.forename: P-L
authors.initials: PL
authors.lastname: Lam
authors.affiliation: Centre of Biotechnology, Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Gambari
authors.affiliation: Ministry of Education (MOE) Key Laboratory for Regenerative Medicine, School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong, SAR, P.R. China.
authors.forename: S H-L
authors.initials: SH
authors.lastname: Kok
authors.affiliation: State Key Laboratory of Chirosciences, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, SAR, P.R. China.
authors.forename: K-H
authors.initials: KH
authors.lastname: Lam
authors.affiliation: State Key Laboratory of Chirosciences, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, SAR, P.R. China.
authors.forename: J C-O
authors.initials: JC
authors.lastname: Tang
authors.affiliation: Clinical Division, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, SAR, P.R. China.
authors.forename: Z-X
authors.initials: ZX
authors.lastname: Bian
authors.affiliation: Ministry of Education (MOE) Key Laboratory for Regenerative Medicine, School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong, SAR, P.R. China.
authors.forename: K K-H
authors.initials: KK
authors.lastname: Lee
authors.affiliation: State Key Laboratory of Chirosciences, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, SAR, P.R. China.
authors.forename: C-H
authors.initials: CH
authors.lastname: Chui
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D001228:Aspergillosis / Q000188:drug therapy*; D001234:Aspergillus niger / Q000254:growth & development*; D002214:Capsules; D002478:Cells, Cultured; D003881:Dermatomycoses / Q000188:drug therapy*; D004353:Drug Evaluation, Preclinical; D005707:Gallic Acid / Q000737:chemistry / Q000494:pharmacology*; D005780:Gelatin / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism; D012685:Sepharose / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D002214:Capsules; D005707:Gallic Acid; D005780:Gelatin; D012685:Sepharose