title: Preparation of nanoscale Bacillus thuringiensis chitinases using silica nanoparticles for nematicide delivery.
abstract: A series of amino, carboxylic, and aldehydic surface-grafted silica nanoparticles (SNPs) was prepared based on SiO2 NYSi40 nanoparticles to develop an efficient, biocompatible, and cost-effective biopesticide delivery system. Bacillus thuringiensis chitinase (Chi9602) was immobilized onto SNP surface to prepare nanoscale chitinases (SNPCs) through electrostatic adsorption and covalent binding. The specimens were characterized by Fourier transform infrared, scanning electron microscopy, and zeta-potential analyses. The delivery capacity of the SNPs in Caenorhabditis elegans N2 was observed by immunofluorescence. Results demonstrated that amino-grafted SiO2 nanoparticles with Chi9602 electrostatically adsorbed onto their surface (SNPC2) exhibited a relatively high enzyme immobilization rate (80.2%) and the highest (94.1%) residual enzyme activity among all SNPCs. SNPC2 also showed wider pH tolerance and relatively higher thermostability and ultraviolet radiation resistance capacity than Chi9602. Bioassays further showed that SNPC2 synergistically enhanced the nematicidal effect of B. thuringiensis YBT-020 preparation against C. elegans, with a reduced LC50 of 8.35mg/mL and a shortened LT50 of 12.04h. Immunofluorescence assays showed that SNPC2 had considerable delivery capacity to carry a large protein into C. elegans. Therefore, SNP2 can serve as an efficient nanocarrier for the delivery of macromolecular proteic biopesticides or drugs, indicating potential agricultural or biotechnological applications.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Qin
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Xiang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Faculty of Life Science, Hubei University, Wuhan 430062, China.
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Sun
authors.affiliation: Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Faculty of Life Science, Hubei University, Wuhan 430062, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Ni
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: lilin@mail.hzau.edu.cn.
authors.forename: Lin
authors.initials: L
authors.lastname: Li
mesh_terms: D000818:Animals; D000969:Antinematodal Agents / Q000008:administration & dosage*; D001413:Bacillus thuringiensis / Q000201:enzymology*; D017173:Caenorhabditis elegans / Q000187:drug effects; D002688:Chitinases / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry*; D016503:Drug Delivery Systems; D004789:Enzyme Activation; D004800:Enzymes, Immobilized / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D000969:Antinematodal Agents; D004337:Drug Carriers; D004800:Enzymes, Immobilized; D012996:Solutions; D012822:Silicon Dioxide; D002688:Chitinases
keywords: Biocontrol agent; Chitinase; Nanocarrier; Silica nanoparticles; Surface grafting