Study On The Construction And Release Properties Of PLGA Microsphere Scaffolds Loaded With Vancomycin Hydrochloride

Chronic osteomyelitis,a major challenge in clinical treatment,requires the drug delivery system used for osteomyelitis treatment to achieve sustained release and play a supporting role in the site of bone defect.In order to meet the needs of clinical applications,three different poly(lactic-co-glycolic acid)(PLGA)microspheres with different release properties were prepared based on the coagulation bath shear method.Two PLGA microspheres were then assembled in different mass ratios and different combinations of inner and outer layers to construct a double-layer drug-loaded microsphere scaffold.Then we study their release properties and patterns.In order to further reduce the burst release rate of single microspheres,prolong drug release time,and regulate the acidic environment caused by PLGA degradation products,a series of PLGA/CS microspheres and PLGA/CS microspheres scaffolds were prepared by composite chitosan(CS)on the surface of PLGA microspheres.In this paper,we utilize chitosan composite on the surface of PLGA microspheres to prepare a series of PLGA/CS microspheres and its scaffolds,and investigate the properties of PLGA/CS microspheres and the release behavior and degradation of PLGA/CS microspheres scaffolds in vitro.The results showed that the prepared PLGA microspheres A1,A2 and A3 had different particle size,drug loading,encapsulation efficiency and in vitro release behavior.When the double-layer microsphere scaffolds were prepared based on three microspheres,the scaffolds can exhibit different drug release effects by changing the types and mass ratios of the inner and outer microspheres in the scaffolds.The effect of chitosan on the surface of PLGA microspheres can change the particle size and Zeta potential and the surface roughness of the microspheres.With the increase of chitosan content in the microspheres,the drug loading and encapsulation efficiency of PLGA/CS microspheres decreased,and the burst release rate of PLGA/CS microspheres and its scaffolds gradually decreased,and the sustained release time was gradually prolonged.The rate of mass loss of PLGA/CS microsphere scaffolds and the pH-decreasing rate of degradation fluids were gradually slow.In this paper,the double-layer microsphere scaffolds and PLGA/CS microsphere scaffolds constructed can improve the drug release performance of PLGA microsphere scaffolds to some extent.All the drug-loaded microsphere scaffolds prepared have good biocompatibility and good antibacterial properties.This study provides a new strategy for the construction of drug delivery system for clinical treatment of osteomyelitis.