Preparation And Characterization Of PHBV Antibacterial Composite

Nowadays,medical devices play an important role in medical treatment,helping simplify the diagnosis of the disease,relieving the suffering of patients,improving the probability of success of surgery and saving millions of lives.However,some medical equipments could induce infection in their application,which is a great threat to the health of people.Catheter is a kind of medical equipment s,which is used by patients with severe renal diseases and other patients who can not be self micturition.Most of the existing catheter have no antibacterial effect,and the usage of catheter is easy to cause infection in clinic.Therefore,it is important to do research on self-antibacterial and can biodegradable catheters.The study was divided into two parts.The first part of this study was to modify the surface of PHBV.Firstly,pure PHBV films were prepared by the solvent casting method,and the compound solution of baicalin was coated on the surface of PHBV film,then the baicalin/PHBV composites with different drug loading doses were prepared.The results of antibacterial experiments showed that the composite material with 12% drug loading had a stable antibacterial effect.Therefore,the 12% baicalin /PHBV composite was selected as the experimental group in the follow-up experiments.The results of drug release experiment showed that baicalin/PHBV composite material has the effect of slow release.The cumulative amount of drug release reached 73.3%,after they were soaked in PBS solution for eleven days.The degradation experiment results showed that the weight loss rate of Baicalin/PHBV composites reached 62%,when they had been buried in soil for sixty days.The result of cell biological characterization showed that MG-63 cells were able to attach and grow on the surface of the composite materials,which mean that the material had good biocompatibility.In the second part,silver nanoparticles were used as antibacterial agent.The surface of PHBV films were modified by chemical grafting method.Several factors that influence the particle size were studied.The average particle size of silver nanoparticles(Ag NPs)less than 10 nm.Fourier transform infrared spectroscopy results show that the success of the methyl acrylic acid grafted to PHBV membrane material surface,and gelatin was fixed by the amidation reaction.FESEM picture showed that the silver nanoparticles were distributed on the surface of PHBV film,and there was no large-scale aggregation.The results of antibacterial experiment showed that Ag NPs/PHBV composites had good antibacterial properties.Ag NPs/PHBV composites still have antibacterial property after they have been soaked in PBS solution for 8 days,which meet the requirement of disposable catheters.The result of degradation test showed that the degradation rate of Ag NPs/PHBV composites was slightly higher than that of pure PHBV film materials,and the weight lo ss rate reached 66% in 60 days.MRC-5 cells on the surface of the material expanded well and displayed healthy appearance.The results of RT-PCR showed that the Ag NPs/PHBV composites had no obvious toxic effects on the cells.Ag NPs/PHBV composites as a biodegradable antimicrobial composite material is potential to replace the existing catheter used in clinical.