Preparation And Application Of Hypochlorous Acid Sustained-release Hydrogel

Hypochlorous acid has certain oxidation ability and can kill Gram-positive and gram-negative bacteria through REDOX reaction at a low concentration.It is a mild broad-spectrum bactericide and has a wide range of applications as it is non-irritating,non-sensitizing and non-corrosive to mammals.However,hypochlorous acid has the disadvantages of volatile decomposition,fast bactericidal effect and not lasting bactericidal effect.The hypochlorous acid was adsorbed by the carrier and then released,which could prevent the volatilization and decomposition of hypochlorous acid,slow discharge and prolong the drug effect.Hydrogels are a kind of hydrophilic gels with three-dimensional polymer crosslinked network,which have excellent hydrophilic and water-retaining properties,and good biocompatibility.Hydrogel materials with bioaffinity obtained by regulating the composition and structure of hydrogels have attracted much attention in the fields of biomedicine and health care.The loading and releasing of hypochlorous acid using the network structure formed by hydrogel three-dimensional crosslinking can provide a new way to realize the sustained release of hypochlorous acid.In this paper,two amphotic hydrogels,poly [2-(methylacryloxy)ethyl] dimethyl–(propyl3-sulfonate)ammonium hydroxide(PSBMA)hydrogels,and [2-(methylacryloxy)ethyl] dimethyl–(propyl3-sulfonate)ammonium hydroxide copolymerized carboxymethyl chitosan hydrogels(PSBMA/CMCS),were prepared.The properties of these two materials in load and slow release hypochlorous acid were studied.The specific research is as follows:(1)PSBMA hydrogels and PSBMA/CMCS hydrogels were prepared by polymerization method of free radical REDOX,and the two hydrogels were characterized by scanning electron microscopy,Fourier infrared spectroscopy,thermal analysis,mechanical analysis,water contact Angle test,etc.The characterization results showed that the two hydrogels had obvious pore structure,excellent adhesion,antifouling ability,hydrophilicity and water content.Compared with PSBMA hydrogels,the pore size of PSBMA/CMCS hydrogels was reduced by 30 μm,the water content was increased by 14.9%,the water contact angle was reduced by 98.5°,and the hydrophilicity was enhanced.(2)The effect of the amount of monomer on the loading and release of PSBMA hydrogel was studied.The optimal amount of monomer was determined to be 50(w/v).The optimal conditions for sustained release of hypochlorous acid in vitro were discussed,and the factors affecting the sustained release of hypochlorous acid under practical application were investigated,including ionic strength(0.9%(m/v)),pressure(0.4 N),ultrasonic time(30 min before each test),and temperature(4 ℃,room temperature,40 ℃,60 ℃).Among them,ionic strength,pressure,ultrasonic and other factors almost do not affect the slow release of hypochlorous acid,but with the increase of temperature,the release of hypochlorous acid will be accelerated.In order to reduce the influence of temperature on slow release of drugs,PSBMA/CMCS hydrogels were prepared by adding carboxymethyl chitosan into copolymer system.Due to the temperature-insensitive property of carboxymethyl chitosan,the temperature sensitivity of hydrogel is effectively reduced,thus reducing the effect of temperature on the slow release of hypochlorous acid.(3)The PSBMA hydrogels and PSBMA/CMCS hydrogels loaded with hypochlorous acid solution were tested for bacteriostatic effects,and it was found that both hydrogels had good bacteriostatic effects.