Microwave synthesis of ZnO[at]mSiO sub(2) for detailed antifungal mode of action study: Understanding the insights into oxidative stress

• Published in: Journal of colloid and interface science 2015-04, Vol.444, p.97-108
• Main Authors: Mitra, Shouvik, Patra, Prasun, Pradhan, Saheli, Debnath, Nitai, Dey, Kushal Kumar, Sarkar, Sampad, Chattopadhyay, Dhrubajyoti, Goswami, Arunava
• Format: Article
• Language: English
• Subjects: Biochemistry; Biocides; Biocompatibility; Fungi; Hydrazones; Nanoparticles; Nanostructure; Stresses; Zinc oxide
• ISSN: 0021-9797
• DOI: 10.1016/j.jcis.2014.12.041

A simple chemical method has been devised for deliberate incorporation of zinc oxide nanoparticles (ZNPs) within mesoporous nanosilica (mSiO sub(2)) matrix to yield zinc oxide nanoparticles embedded in mesoporous nanosilica (ZnO[at]mSiO sub(2)). ZnO[at]mSiO sub(2) inhibited the growth of four strains of fungi in a dose dependant manner. A series of biochemical assays revealed generation of oxidative stress from ZnO[at]mSiO sub(2) for such biocidal response. We proposed transient superoxide and its subsequent conversion to H sub(2)O sub(2) played a pivotal role behind such biocidal response as revealed from our systematic evaluation. This resulted morphological alteration of fungi through increase in number of facets, in correlation we found up-regulation in oxidative stress related genes. Bioavailability within the fungal sample was confirmed from microscopic, spectroscopic, biophysical techniques. Protein carbonylation of fungal species was the chemical outcome of such above mentioned stress and quantified by high performance liquid chromatography (HPLC) via subsequent hydrazone derivatization. Several in vitro and in vivo evaluations revealed the biocompatibility of ZnO[at]mSiO sub(2). Altogether this report claims a new biocidal agent with a detailed mode of action focusing on the origin and quantification of oxidative stress through biophysical and biochemical techniques for the first time for real time applications.