功能化介孔碳纳米球负载银离子的光热协同抗菌研究

A synergistic photothermal antibacterial system based on silver-infused functionalized mesoporous carbon nanospheres

耐抗生素菌株的出现严重降低了传统抗生素疗法的效率。开发一种有效消除这种细菌感染的新型替代抗生素疗法变得至关重要。光热治疗(PTT)具有组织渗透性、时空可控性、不产生耐药性且能广谱抗菌等优点,但PTT的高效杀菌效果通常需要极高温度(55~65℃),此过程不可避免会对正常组织造成损伤。银纳米粒子(AgNPs)被用作广谱抗菌剂,其抗菌活性主要来源于银离子(Ag^(+))的释放。然而,过量的AgNPs不仅会对机体产生毒性,而且还会造成贵金属的浪费。本课题采用氧化后的介孔碳纳米球(OMCN)作为光热材料负载Ag^(+)制备复合材料OMCN-Ag^(+)。该体系不仅具有高效抗菌活性,还能减少贵金属Ag的浪费及降低毒副作用,此外,精确控制的温和光热可克服传统光热抗菌过程中温度过高对正常组织造成的损伤。该抗菌治疗体系在体内和体外都有良好的生物相容性,且能有效清除小鼠伤口感染部位的细菌,从而促进小鼠伤口愈合。本研究中动物实验均按照河南大学动物实验伦理委员会批准的指导方针进行。

The emergence of antibiotic-resistant strains seriously reduces the efficiency of traditional antibiotic therapy.The development of a new alternative antibiotic method to effectively eliminate this bacterial infection has become a critical issue.Photothermal therapy(PTT)has shown many advantages in tissue penetration,spatiotemporal specificity,no drug resistance and broad-spectrum antimicrobial ability.However,extremely high temperature(55-65℃)is needed to achieve highly efficient bactericidal effect during PTT treatment process.Thus,this procedure will inevitably cause collateral damage to normal tissues.Silver nanoparticles(AgNPs)are one of the most commonly used broad-spectrum antimicrobial agents.Its antimicrobial activity is mainly derived from the release of silver ions(Ag^(+)).However,excessive AgNPs not only would cause toxic to the body,but also waste precious metals.In this study,oxidized mesoporous carbon nanospheres(OMCN)were used as photothermal materials to prepare OMCN-Ag^(+)composites.The composite material can improve the antibacterial activity,reduce the waste of metal Ag and decrease the toxic and side effects.Moreover,the precisely controlled mild heat can overcome the shortcoming such as the damage to normal tissue caused by the excessive temperature during traditional photothermal antimicrobial process.The antimicrobial treatment system exhibits a good biocompatibility both in vitro and in vivo.Specially,the designed nanosytem can effectively eliminate the bacteria from the infected wound,subsequently promoting the process of wound healing.All animal experiments were carried out with approval of the Animal Experiment Ethics Committee of Henan University.