Novel hydantoin based co-polymers containing both amide and imide positions for halogen capture with improved rechargeability and antibacterial activity were developed.
A stainless steel surface was functionalized with a novel hydantoin based copolymer and evaluated for antibacterial activity, anti-biofilm activity, and biocompatibility.
A new approach for the design and synthesis of cyclic N-halamine polymers having anti-bacterial activity based on a vinyl derivative of tyrosine-derived hydantoin is reported. The synthesis of N-halamine polymers generally involves the chemical modification of 5,5'-disubstituted hydantoin to introduce polymerizable vinyl moieties thereby restricting the halogen capture only on the amide nitrogen. Here we show the possibility of synthesizing vinyl monomers of N-halamine from α-amino acids wherein both the amide and imide nitrogens are available for halogen capture. Thus, a hydantoin monomer was synthesized from L-tyrosine and copolymerized with methyl methacrylate and 2-(hydroxyethyl)methacrylate, to obtain random co-polymers. The monomer and its co-polymers were characterized using NMR, IR, HRMS, GPC, DSC, EDAX and TGA analysis. Films of the co-polymers cast from 10% acetone solutions were exposed to sodium hypochlorite solution to activate the hydantoin moieties. The oxidative chlorine content of the films ranged from 0.6 to 0.9%. The activated films were exposed to both Gram positive (S. aureus) and Gram negative (E. coli) bacteria using standard protocols. Polymers having chlorine content as little as 0.6% exhibited 6 log reduction in the bacterial growth within 30 min of exposure. The method allows the halogenation of both amide and imide nitrogens and could be applied to the preparation of a number of vinyl hydantoins from many amino acids.
hearing loss). Of the 13 applicants of age ≦ 12 years, eight were diagnosed with brainstem evoked response audiometry, and 10 had HI score of ≥ 70%. Muslim population with SNHL tended to avail certification 1.34 times more than the Hindus. Most of the applicants with mixed hearing loss (MHL; n = 24) were in their fifth and sixth decades (29.2% each), with three times male preponderance. Among the malingerers, the average malingering impairment was 66% (median: 61%; range 44-100%). Among the SNHL population, ~ 30% had HI at 90-100% in contrast to the MHL population of whom 8% had HI at > 90% and 29% had HI at 40-< 55%. Ten applicants among the organic hearing loss group (6.76%) (two with SNHL; eight with MHL) had HI scores of < 40% and were considered ineligible for certification. The outcomes of the review provided a comprehensive account of the socio-demographic profile of the applicants for handicap certification and the type of hearing loss prevailing in a given population. These data, and the severity stratification of the hearing disability through the HI% scale would provide the policymakers and stakeholders with proper directions to work upon.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.