Preparation And Characterization Of Vancomycin Hydrochloride-loaded Mesoporous Silica Composite Hydrogels

Objective: The aim of this study was to construct vancomycin hydrochloride-loaded mesoporous silica composite hydrogels(Van/SBA-15/CS-GP-SA)and to investigate the microstructure,slow-release properties,cytocompatibility and bacterial inhibitory properties of the hydrogel in order to provide a new antibacterial slow-release carrier for the construction of tissue-engineered bone.Methods: 1.Preparation and characterization of vancomycin hydrochloride-loaded mesoporous silica(Van/SBA-15): Van/SBA-15 was prepared using the mesoporous silica(SBA-15)as a carrier for vancomycin hydrochloride(Van).Van/SBA-15 was characterized by Scanning electron microscopy(SEM),Transmission electron microscopy(TEM),Energy dispersive spectrometry(EDS),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared(FTIR),nitrogen adsorption-desorption,and a study of its drug loading.2.Preparation and characterization of vancomycin hydrochloride-loaded mesoporous silica composite hydrogels(Van/SBA-15/CS-GP-SA): Van/SBA-15/CS-GP-SA is constructed by encapsulating Van/SBA-15 in chitosan–sodium glycerophosphate–sodium alginate hydrogel(CS-GP-SA).The microstructures,sustained-release ability,biocompatibility,and antibacterial properties of Van/SBA-15/CS-GP-SA were systematically studied.Results: 1.Scanning electron microscopy and transmission electron microscopy results showed that the surface of the drug-loaded SBA-15 appeared as flaky Van particles and the pore channels became blurred.X-ray photoelectron spectroscopy showed that the characteristic peaks of Van.N1 s and Cl2 p at 400.3 e V and 201.6 e V,respectively,were present in SBA-15.The FTIR results showed that the characteristic vibrational absorption peaks of both Van and SBA-15 were present in the drug carrier SBA-15.The results of nitrogen adsorption-desorption showed that the nitrogen adsorption capacity of the drug-loaded SBA-15 was lower than that of the blank carrier,and the pore size,pore volume and specific surface area were all reduced.The results showed that SBA-15 was successfully loaded with Van and its encapsulation rate was 36.8 %.2.SEM images showed that the blank hydrogel(CS-GP-SA)group,vancomycin-loaded hydrogel(Van/CS-GP-SA)group and Van/SBA-15/CS-GP-SA group all showed porous structures.The Van/SBA-15/CS-GP-SA group had the largest pore size and the roughest pore wall compared to the CS-GP-SA and CS-GP-SA groups.The results of in vitro release experiments showed that the cumulative release rates of Van in the Van/SBA-15,Van/CS-GP-SA and Van/SBA-15/CS-GP-SA groups were(94.6±1.37)%,(83.7±2.10)% and(73±1.76)% at day 15 and(99.1±0.13)% at day 30,respectively.99.1±0.13)%,(93±0.47)% and(84±0.64)% respectively.The results of the cell experiments showed that there was no significant difference between groups in the Cell Counting Kit-8(CCK-8)experimental data on days 1,3 and 5 for the blank control,CS-GP-SA,Van/CS-GP-SA and Van/SBA-15/CS-GP-SA groups(P > 0.05),and the number of cells in each group increased with time(P < 0.05).Also,the DAPI stained images verified the CCK-8 results.The results of the inhibition assay showed that the Van/SBA-15/CS-GP-SA group had a significant ring of inhibition.Conclusions: 1.The vancomycin hydrochloride-loaded mesoporous silica composite hydrogels(Van/SBA-15/CS-GP-SA)has stable properties,ideal slow release performance,excellent cytocompatibility and obvious bacterial inhibition effect.2.The composite hydrogel can basically meet the requirements as a bacterial inhibition and slow release carrier for tissue engineered bone,and is expected to provide a new bacterial inhibition strategy for tissue engineered bone.