| At present,porcine acellular dermal matrix dressing for different degrees of burn treatment has become a hot spot of research.The current products generally have low antibacterial properties,low biological activity and permeability,this limits the application of the dressing in clinic.In view of the main deficiencies of porcine acellular dermal matrix dressing,this paper has use chitosan with excellent biological properties composite with porcine acellular dermal matrix to solve the faults.This subject adopts the oxidative degradation method to produce chitosan and select a kind of chitooligosaccharide.In combination with our previous research,on the basis of pig skin as raw material,we adopt the method of combination of physical,chemical and biological to make a kind of porcine acellular dermal matrix(PADM)and crosslinked with chitooligosaccharide(COS).We prepared a kind of antimicrobial porcine acellular dermal matrix dressing(COS-PADM)eventually.This topic has mainly studied the influence of hydrogen peroxide degrade the molecular weight of chitosan.the bacteriostasis of chitosan of different molecular weight and the preparation technology of crosslinked porcine acellular dermal matrix with chitosan.The main conclusions are as follows:(1)Firstly in view of the concentration of reaction time and concentration of acetic acid,hydrogen peroxide for the degradation of chitosan,research has shown that with the increase of time,the molecular weigh of chitosan decrease,the rate of first hours of reaction is bigger.When acetic acid mass fraction was 3%,in the same condition,the degradation of the molecular weight of chitosan was the lowest.With the increase of hydrogen peroxide mass fraction,the molecular weight of chitosan decreases.When the hydrogen peroxide mass fraction is more than 4%.the decline rate is very low.The effect of three of the reaction conditions on degradation of chitosan:reaction time>acetic acid>hydrogen peroxide concentration.(2)In view of the antibacterial effect on the different molecular weight(700,3000,6000,9000,12000)of chitosan by using staphylococcus aureus and escherichia coli,research has shown that for staphylococcus aureus,the molecular weight of 9000 and 12000 has best antibacterial effect,and the minimum bacteriostasis concentration was 0.25%.For e.coli,the molecular weight of about 3000,6000,9000,chitosan has good antibacterial property,and the minimum bacteriostasis concentration was 0.25%.According to the results,I choose the molecular weigh of chitosan about 9000 to crosslink with porcine acellular dermal matrix.(3)I crosslinked chitosan with porcine acellular dermal matrix and characterized the physical and chemical properties of it.The experimental results show that,with the increase of dosage of chitosan,the material porosity,the enzymatic hydrolysis resistance time,tensile strength are increasing.The permeability is declining.The antibacterial experiments show that the COS-PADM has certain antimicrobial properties,and with the increase of chitosan concentration,antimicrobial properties gradually increased.To a certain extent,COS-PADM inhibit the growing of staphylococcus aureus and escherichia coli.(4)According to the results of the above(1)(2)(3),combined with the clinical actual requirements and cost considerations,I decide to use 3.00%chitosan.In this condition,the antimicrobial chitosan crosslinked with porcine acellular dermal matrix dressing with permeability of 2947.8 g·m-2·24h-1,porosity of 93.83%,the tensile strength of 11.91MPa,the enzymatic hydrolysis resistance time of 25h.The of antimicrobial chitosan crosslinked with porcine acellular dermal matrix dressing has certain antimicrobial properties and good permeability,and also has the potential of other biological characteristics.It meet the requirements of dressing in burn treatment mainly.This topic is expected to lay a foundation for later product development. |
PDF Full Text Request