含硫氨基酸缀合氮化硼纳米片强化植物精油的智能缓释与长效抗菌作用机制

天然植物精油是饲料禁抗后畜禽养殖领域替抗的研究热点。申请人前期研究发现二维材料六方氮化硼（h-BN）对精油具有良好的负载能力，有利于精油在畜禽肠道的缓慢释放，但对精油分子的精准调控能力有限，且精油分子在片层限域通道中的长效传递扩散及抗菌机制尚不明确。因此，本项目拟采用六方氮化硼纳米片（BNNS）结合共价键引入含硫氨基酸（SSA）进行插层组装，构筑主体（BNNS）-分子阀门（SSA）-客体（精油）结构，形成具有适应畜禽肠道微环境的氧化-还原和pH双重刺激响应性的智能缓释体系。通过组分设计和介观诱导，建立SSA在BNNS纳米片层限域的插层组装路线，揭示其结构、尺寸、界面效应的调变规律；通过对体系构效关系的深入研究，阐明精油分子在BNNS-SSA片层纳米通道的功能耦合和长效传递机制，揭示BNNS-SSA纳米载体强化精油的长效抗菌作用机制，为畜禽养殖业替抗产品的开发提供新的思路及理论支撑。

Nowadays, essential oil extracted from natural plant has come into a spotlight as alternatives to antibiotics in the field of livestock and poultry breeding after the prohibition of antibiotics. Our preliminary work showed that hexagonal boron nitride (h-BN), a kind of two-dimensional material, possesses an excellent loading capacity for essential oils, which is conductive to the slow release of essential oils in the intestines of livestock and poultry, however, the precise controlled ability for essential oil molecules is limited, meanwhile, the long-term transmission and diffusion mechanism of essential oil molecules in the lamellar nanoconfined channels and the long-term antibacterial mechanism are still unclear. Herein, this proposal aims to controllably synthesize functionalized boron nitride nanosheets (BNNS) as the main carrier for essential oils, and then conjugated via covalent bonds by intercalation with sulfur-containing amino acids (SSA) into the interlayer confinement to act as the molecular valve. A multi-functional nano-based smart controlled release system with host (BNNS)-molecular valve (SSA)-guest (essential oil) structure will be constructed which can be responsive to dual stimuli (oxidation-reduction and pH) adapting to the intestinal microenvironment of livestock and poultry. The route of SSA intercalated into BNNS nanoconfinement layers will be established through component design and mesoscopic induction, and the precise regulation of structure, size, and interface effect of nanocarriers will be explored and revealed. The long-term transport and release mechanism of essential oils in carrier’s channels with multi-functional properties will be revealed through systemically investigation of the intrinsic structure-activity relationship among the system, furthermore, the long-term antibacterial mechanism of essential oils strengthen by BNNS-SSA and synergistic mechanism of “BNNS-SSA-essential oil” system will be systematic evaluated. This proposal can provide a new idea for development of alternatives to antibiotics in the field of livestock and poultry breeding, and give a scientific basis for smart controlled release of essential oils and further promote the effective utilization of essential oils.