Preparation Of Tanshinone ?A/Silver Nanocomposites Gel And Its Application In The Treatment Of Otitis Media

Otitis media as a common clinical and frequently-occurring disease has a serious impact on human health and quality of life.Topical application of antibiotics has important implications for the treatment of otitis media,but its resistance and potential ototoxicity limited its application.Research on new antibacterial,anti-inflammatory drugs,especially those containing traditional Chinese medicine have important clinical value.Given the the reasons above,there is a pressing need for a strategy for drug combinations to combat multi-drug resistance.Through the synergistic effect of drugs can maximize the treatment effect while reduce the side effects of drugs.Therefore,a combination of traditional Chinese medicine Tanshinone IIA and inorganic silver nanoparticles(AgNPs)were designed in this study,and put them in gel,then applied in the treatment of otitis media and conduct safety studies.In this study,AgNPs were synthesized for the first time using an antibacterial endophytic fungus of Chinese medicinal herb Orchidantha chinensis,which has anti-inflammatory and antimicrobial activities.The AgNPs were analyzed by various characterization techniques to reveal their morphology,chemical composition,and stability.The results showed that spherical and near spherical AgNPs were synthesized by using the aqueous extract of OC14 strain and silver nitrate.The average particle size of the prepared silver nanoparticles was 46.1 nm.The CS-AgNPs and the Lys-AgNPs were prepared by co-incubation.The different chitosan models and concentrations were compared with the ratio of nano-silver colloidal solution and chitosan solution.HP-?-CD inclusion complex loaded with Tanshinone IIA was prepared by an unsaturated alcohol solution method.Then the Tanshinone IIA/silver nanocomposites(TSIIA/AgNPs)were formed by co-incubation of the above two substance.The composites with strong antibacterial activity were studyed by disk diffusion method and broth dilution method.The results showed that TSIIA/AgNPs has synergistic effect.TSIIA and AgNPs alone has smaller inhibition zone.In vitro release results showed that the release time of TSIIA/AgNPs solution was about 7 days,and the release time of Tanshinone IIA was only 1.5 days,indicating that the preparation had a more obvious sustained release effect.In this paper,the gelatin matrix material PLGA was used to prepare the in situ gel of TSIIA/AgNPs,and the yellowish brown or reddish brown translucent liquid was obtained by using the formation principle of polymer precipitated in situ gel.They can solidificate in PBS quickly and form spherical droplets,after the completion of solvent exchange into a yellowish orange or reddish brown semi-solid gel reservoir.And its drug release behavior was investigated,showing a more significant sustained release effect than the solution.The middle ear lavage and middle ear epithelium were collected and the TSIIA levels of TSIIA/AgNPs were determined by HPLC.The Cmax of TSIIA/AgNPs gels were 8.05±3.49 ?g/m L and 10.67±4.27 ?g/m L,respectively,which were significantly higher than those of 3.08±1.73 ?g/mL of solution and 3.93±1.10 ?g/mL.The AUC0-t of the gel is nearly 3 times higher than the area under the solution.The results showed that TSIIA/AgNPs gel can significantly improve the bioavailability in the middle ear cavity,and prolong the residence time in the body,so that the drug can give full play to the efficacy.The guinea pig otitis media model was established by tympanic injection of Staphylococcus aureus,and the bacterial colonies were counted at different time points after tympanic injection.The results showed that the amount of bacteria in all groups were decreased,indicating that the drug has a certain efficacy.The amount of bacteria in TSIIA/AgNPs group(243×104 CFU/mL)was significantly lower than the AgNPs group(343×104 CFU/mL)and TSIIA inclusion compound group(530×104CFU/m L)at 24 h.At the end of the treatment,TSIIA/AgNPs treatment group showed lower TNF-? and IL-8 levels in middle ear lavage and the inflammatory cell infiltration in middle ear mucosa was observed.The levels of inflammatory cells were significantly reduced in the ofloxacin ear drops group and the TSIIA/AgNPs group,indicating that TSIIA/AgNPs has a certain anti-bacterial,anti-inflammatory effect,which can be applied to the treatment OM.There is no lack of inner and outer hair cells after TSIIA/AgNPs gel administration in the safety evaluation,proving they are safe in OM treatment.In summary,this study has designed such a multi-antibacterial nano-drug delivery system for the new Chinese medicine composition combined with inorganic nano-drug delivery system.It will play an important role in biomedical applications in near future.