A micro-nano optogenetic system based on probiotics for in situ host metabolism regulation

Genetically engineered bacteria have aroused attention as micro-nano drug delivery systems in situ.However,conventional designs of engineered bacteria usually function constantly or autonomously,which might be non-specific or imprecise.Therefore,designing and optimizing in situ control strategy are important methodological progress for therapeutic researches of intestinal engineered bacteria.Here,a micro-nano optogenetic system based on probiotic was developed combining microelectronics,nanotechnology,and synthetic biology to achieve in situ controllable drug delivery.Firstly,optogenetic engineered Lactococcus lactis was orally administrated in the intestinal tract.A wearable optical device was designed to control optical signals remotely.Then,L.lactis could be customized to secrete peptides according to optical signals.As an example,optogenetic L.lactis system can be constructed to secrete glucagon-like peptide-1(GLP-1)under the control of the wearable optical device to regulate metabolism.To improve the half-life of GLP-1 in vivo,Fc-domain fused GLP-1 was optimally used.Using this strategy,blood glucose,weight,and other features were well controlled in rats and mice models.Furthermore,upconversion microcapsules were introduced to increase the excitation wavelength of the optogenetic system for better penetrability.This strategy has biomedical potential to expand the toolbox for intestinal engineered bacteria.

Synthesis of mesoporous silica microspheres by a spray-assisted carbonation microreaction method

A novel spray-assisted carbonation microreaction method for the synthesis of mesoporous silica microspheres is reported.The synthetic process comprises the preparation of a silica sol via a carbonation reaction,rapid gelation at high temperature,and subsequent rapid solvent evaporation by spray drying.The carbonation microreaction was conducted in a membrane dispersion microreactor,in the presence of sodium silicate and carbon dioxide reactants.The as-synthesized silica microspheres exhibit a uniform mesostructure,excellent dispersity,and a narrow particle size distribution,with average diameters of 1-2 μm,Brunauer-Emmett-Teller surface areas of 300-1149m2/g,and total pore volumes of 0.21-1.82 cm3/g.Relatively low concentrations of the silicate species and well-controlled silica condensation rates are responsible for the formation of the observed spherical morphology.The synthetic process is of significant practical importance as a result of using low-cost raw materials,and because of the excellent controllability and process stability displayed.Furthermore,this rapid and flexible method may be extended to the synthesis of various silica materials and their composites.