Construction And Membrane Permeability Performances Of Multi-responsive Proteinosome

Biocompartmentalization represents an extremely efficient organization of membranes and biomolecules that is needed to cope with a complex scenario of metabolic reactions in a confined space.It is a prerequisite attribute of all living systems and is increasingly recognized as an essential paradigm of synthetic cellularity,and an important consideration for developing new strategies to create novel functional ensembles.Over the past years,strategies toward membranedelineated compartmentalization have been widely developed mainly focusing on the use of a diverse range of amphiphilic building blocks that undergo spontaneous or directed assembly in solutions to produce microcompartments including liposomes,polymersomes,colloidosomes.Since discovery,they have been frequently utilized to construct drug delivery nanocarriers and nanoreactors.It should be noted that all of these functions are related to the exchange of substances between the outside and inside milieu.The key element for fabrication of the suitable microcompartments is the design of membrane materials which are tailored to undergo a chemical or physical change in response to external stimuli triggering such as pH,temperature,shear-rate,light,redox species,enzymes,magnetic and electric fields.As a consequence,the designed stimuli-responsive microstructure could selectively respond to external stimuli and in turn switch the permeability of membrane and show a combined stimuli with a continuous modulation of the membrane permeability and a concomitant programmable release is significant.The main research contents are as follows:Inspired by natural cells,a multi-stimulated response proteinosome was designed and constructed to address the limitations of a single stimulus response.The thiol-modified protein and the poly-N-isopropyl acrylamide?PNIPAAm?polymer having a terminal disulfide are self-assembled into microcapsules at the oil/water interface by the Pickering microemulsion method and dispersed in an aqueous solution.These multiple response models consist of a temperature-sensitive poly-N-isopropylacrylamide polymer,a conjugated disulfide bond on the surface of the membrane,and a pH-sensitive protein.Using a variety of external stimuli such as temperature,redox reagent and pH,the microcapsule membrane permeability is effectively adjusted,and the membrane permeability can be continuously adjusted from 35.2 kDa,78 kDa,102 kDa to 142 kDa by sequential trigger stimulation for programmed release.Based on the temperature,redox agent and pH multistimuli models,a novel photoactive proteinosme was prepared.A multi-response proteinosme based on temperature,light and redox reagent was constructed by copolymerizing photosensitive spiropyran?SP? and temperature sensitive NIPAAm monomers into the polymer on the surface of the membrane.The reversible ultraviolet light triggers the SP-to-McH⁺-to-SP hydrophobic and hydrophobic membrane conversion to achieve dual release of hydrophilic?FITC-dextran? and hydrophobic?Nile Red? substances.Effectively regulates the rate of glucose oxidase?GOx? reaction for light and reducing agent response,and lipase and fluorescein diacetate?FDA?,4-methylumbelliferone?4-MU-Bu?,and membrane-mediated enzymatic reactions such as alkaline phosphatase?ALP? and fluorescein diphosphate?FDP?.In addition,the opening and closing of the ultraviolet-triggered spiropyran polymer enables hydrophobic product capture and re-release.Based on the previous multiple responses modulated membrane-mediated interfacial catalytic reactions,a multi-compartment proteinosome model was constructed.The effect of shearing force on the size of the proteinosome was studied,and the statistical regulation of the number of the internal and external proteinosomes was realized.The programmed release ability of DNA and RBITC-dextran were studied by two kinds of loading substances,and exhibited programmed release behavior when exposed to an aqueous protease solution or when subjected to stepwise addition of a reducing agent?tris?2-carboxyethyl? phosphine?TCEP?? followed by protease.Using this strategy,we show three types of spatiotemporal response based on retarded concomitant release,synchronous release or hierarchical release of dextran and DNA from within the nested proteinosome architectures.An in situ biomimetic proteinosome producing a protein core-shell structure was constructed,and the adsorption capacity of the core was adjusted by the constraint of multiple response membrane permeability.Three different oxidation strategies?including H₂O₂,t-butyl hydroperoxide,glucose oxidase/glucose? were used to achieve in situ formation of the poly?o-phenylenediamine? core inside the proteinosome.By regulating the dissociation of the conjugated polymer on the surface of the multifunctional protein shell or additionally forming a tannic acid/Fe³⁺protective layer,the membrane permeability of the protein capsule is effectively regulated,and the adsorption capacity of the core to the external Cu²⁺ ions is affected.Differing from the normal mode,the adsorption capacity of deprotection model was increased 9.6%.In conclusion,we constructed different kinds of multiple stimuli responsive proteinosomes.Beginning with the membrane permeability of proteinosome,the retention ability of the microcapsule membrane under multiple stimulation response,the programmed regulation ability,the membrane-mediated enzyme catalytic reaction and the effect of membrane permeability on the core adsorption capacity were gradually examined from the outside to the inside.