Development of antimicrobial polyacrylonitrile fabrics by biomodification

Antimicrobial products being currently used aren't satisfying the consumers due to their lack of antimicrobial effect and short shelf life. There are mainly two reasons of these unwanted properties: Inefficiency of the antimicrobial agent (antibiotic resistance) and immobilization method of antimicrobial agent (non-covalent approaches). Antimicrobial products available in the market are mostly disposable materials. Accumulation of these materials causes pollution, and the antimicrobial agents on them present a serious danger for ecosystem. Non-disposable alternatives can be hazardous in various ways. First of all, the agents give them the antimicrobial property are non-covalently bonded on the materials. This causes removal of agents by factors such as washing, using and time; and leads to loss of antimicrobial effect. On the other hand, release of the agent on living organisms or environment pose danger which is even worse if the antimicrobial agent is a heavy metal. Another factor that causes the inefficieny of antimicrobial products is inappropriate and/or constant use of antbiotics which is resulted the situation "antibiotic resistance". It's a well-known fact that, currently used antibiotics will lose their effect in the future. These dangers lead to novel antibiotic researches; which antimicrobial peptides (AMPs) are being the most popular alternatives of these new antimicrobials. AMPs are part of initiate immune system and they have various mechanisms of effect. In the present study, membrane-disrupting AMP, nisin was used. The study was aimed to eliminate those two negative properties of current antimicrobials by developing antimicrobial polyacrylonitrile (PAN) fabrics with constantly effect. Nisin chosen to be able to kill antibiotic-resistant bacteria was immobilized on PAN fabrics microbial-modified and fabrics with constantly antimicrobial effect was obtained. In the present study, Pseudomonas aeruginosa (ATCC 27853) strain was used for biomodification of PAN fabrics by nitrilase enzyme. Biotransformation led the nitrile groups of the fabric has been displaced by carboxyl groups and resulted in formation of more hydrophilic fabrics. Then covalent immobilization of nisin was performed through activation of carboxyl groups. Characterization of the developed producted was carried out and antimicrobial effect was proven by antimicrobial tests. P. aeruginosa (ATCC 27853) and Staphylococcus aureus (ATCC 6538) was used as indicators of antimicrobial effect. The study contains two optimization steps: Optimization of modification and immobilization. With optimization of modification, maximum amount of nitrile groups were displaced by carboxyl groups; and with optimization of immobilization, maximum amount of nisin was immobilized on PAN fabrics.