The Preparation And Release Of Azithromycin-loaded PLGA Microsphere Modified By Silk Fibroin In Vitro

Objective:Periodontitis has great influence on the tooth-supporting structures,and lead to absorption of alveolar bone,even with tooth hypermobility and loss.However,emerging evidence supports the host immune and inflammatory over responses through pathogens and their ‘toxic' products result in progression to periodontitis.Azithromycin is a 15-member ring macrolides.Since the anti-inflammatory,antibacterial and inhibiting Osteoclastogenesis properties the Azithromycin has,it can be used for treatment of periodontitis.Because Oral microenvironment is a particular and complicated anatomical structure,local application is not convenient.So it's necessary to build the drug delivery systems to the oral mucosal adherent preparations.PLGA(Poly-Lactic-Co-Glycolic Acid)is the synthesis of lactic and glycolic acid,of good biocompatibility and biodegradability.The Azithromycin-loaded PLGA microspheres could be made as a sustained drug delivery system.As the PLGA is not conducive for cell adhesion and proliferation due to its hydrophobicity,one could use PAH(Polypropylene Amine Hydrochloride)and SF(Silk Fibroin)to modified PLGA via the layer-by-layer self assembly.As a result,the microsphere has a hydrophilic and also can neutralize the acid degraded by PLGA.It provides a new therapeutic model to achieve the goal of curing periodontitis.Methods:1.Preparation of Azithromycin-loaded PLGA microspheres and detection drug release in vitroPrepare the Aazithromycin-loaded PLGA microspheres by single emulsion-solvent evaporation method.Observe the surface and internal structure of the morphology by SEM and TEM,select the stirring speed to produce the morphology.Calculate the drug loaded and encapsulation efficiency and draw the curves that cumulative release of the azithromycin in vitro.2.Modify the Aazithromycin-loaded PLGA microspheres by PAH and SF andtest drug release in vitroModify the Aazithromycin-loaded PLGA microspheres with PAH and SF by layer by layer method.Observe the surface and internal structure of the morphology by SEM and CLSM.By Zeta potential one can prove the sedimentary of PAH and SF.Calculate the drug loaded and encapsulation efficiency,draw the cumulative curves that release of the azithromycin in vitro.Results:1.With different preparation speed,the size of microspheres particle was significantly different.By measuring different quality of azithromycin-loaded PLGA microspheres drug release,we found that the initial release stage showed a "burst",subsequent release process was relatively stable.With the degradation of PLGA,azithromycin can slow release.2.The PAH and SF can be found on the Aazithromycin-loaded PLGA microspheres surface.By measuring the drug release,we found the modified Aazithromycin-loaded PLGA microspheres has a significantly reduce of releases,azithromycin slow-releasing continuously.Conclusions:1.For different speed of preparation of microspheres morphology,particle size are significantly different.The drug delivery system can be designed by our requirements.2.The loading rate and encapsulation efficiency of the drug loaded microspheres can be increased by improve the drug polymer ratio,but at peak load periods of Aazithromycin,the entrapment efficiency decreased significantly.3.By modifing the Aazithromycin-loaded PLGA microspheres through PAH and SF,the drug release and sustained-release effect can be regulated.4.This research provides the in vitro drug-release profile of the Aazithromycin-loaded PLGA microspheres,thus laid a foundation for further in vivo experiments.