The Synthesis And Characterization Of Silver Nanoparticle-loaded Mesoporous Silica Materials And Its Antibacterial Performance

Infection is one of the common complications of war wound.Moreover,due to the increase of compound wound and the emergence of drug-resistant bacteria,modern war wound infection has become more complicated.Antibiotics possess fast antibiotic sterilization and good antibacterial effect,whereas their application is limited because of the poor thermal resistance.Inorganic antibacterial agents show high stability,long life,and broad-spectrum sterilization.However,occasions and conditions is a great restriction for the use of inorganic antibacterial agents.Therefore,efficient and broad-spectrum antimicrobial agents are highly required and always pursued,offering better protection for future war wound.Ag nanoparticles?Ag NPs?possess diverse advantages,such as broad-spectrum antibacterial ability,good biological safety and strong antibacterial effect.These days,Ag NPs are becoming a research focus among antibacterial materials.However,Ag NPs generally cause practical problems including poor dispersion and poor storage stability,which strictly limited its application.By attaching Ag NPs to mesoporous silica nanoparticles?MSN?,these problems can be improved.Ag NPs are loaded on MSN and MSN with amino or sulfhydryl with different sizes and length-diameter ratios by in situ reduction of adsorbed silver ions.MSN-Ag may prevent Ag NPs from aggregation and sustain the steady release of Ag ions during the antibacterial performance.The characterization of silver-supported MSN is accomplished.Their antibacterial performance to Ecoli,Saureus or Methicillin-resistant Staphylococcus aureus is determined.The relationship between sizes,length-diameter ratio,surface functional group modification of MSN-Ag and its content of silver and antibacterial properties are systemly studied.This study is divided into the following parts:?1?Synthesis and characterization of MSN are accomplished.At room temperature,four groups of MSN are successfully prepared with CTAB as template agent,TEOS as silicon source,ethanol as solvent,adding ammonia water,using sol-gel method under alkaline conditions.As CTAB concentration increase,the morphology of MSN change from ball to rod,and length-diameter ratios of the nanoparticles gradually increase.Four groups of MSN are about 78-299 nm,which length-diameter ratios are1?1.38?2.67?3.73,surface area are 880.45-1256.53 m²/g,pore volumes are 0.79-1.02cm³/g.MSNs have complete mesoporous channels and show excellent essential to load nono silver.?2?The relationship between sizes,length-diameter ratio of MSN-Ag and its content of silver and antibacterial properties is systemly studied.Four groups of MSN-Ag prepared by 4 mmol/L AgNO₃ and 1.1 mmol/L NaBH₄ in situ reduction of adsorbed silver ions,show serried distribution without agglomeration,with a silver content of 6.80-7.27%.MSN-Ag showed antimicrobial activity against Ecoli,staphylococcus aureus and methicillin-resistant staphylococcus aureus?MRSA?.The minimum inhibitory concentration?MIC?of Ecoli,staphylococcus aureus and MRSA?Ag concentration?are 20 mg/L,30 mg/L and 30 mg/L respectively.?3?The relationship between surface functional group modification of MSN-Ag and its content of silver and antibacterial properties is systemly studied.Using complexation of amino and sulfhydryl groups to adsorb silver ions on the surface of MSN-NH₂ and MSN-SH,effectively solve the problem of nano silver reunite.The characterization results show that the silver nanoparticles in MSN-NH₂-Ag are uniformly well-distributed,which are about 5-10 nm and content of 16.85%silver.In the MSN-SH-Ag,the silver nanoparticles are sparse,with large particle size,about5-20 nm and content of 7.73%silver.The antibacterial tests indicated the antibacterial activity of MSN-NH₂-Ag is better than MSN-SH-Ag.MSN-NH₂-Ag with particular size and length-diameter ratio show obvious antibacterial performance to Ecoli,Saureus or MRSA bacteria.Its MIC?Ag concentration?to MRSA is 10 mg/L,inhibiting the growth of MRSA bacteria breeding within 24 hours.