Construction and Property of Biomacromolecules/Nanoparticals/Polymer Hybrid Microcapsules

Author:Wu Guang Zuo

Supervisor:huang yu dong huang zuo


Degree Year:2019





Recently,the design and construction of integrated chemical ensembles for mimicking the key aspects of biological systems attract considerable interest in the field of drug delivery,biosensing,catalysis and synthetic protocellular systems among the different research communities.A range of synthetic vesilces were widely reported based on using various of materials as building blocks including liposomes,polymersomes,colloidosomes and proteinosomes.Single material could not satisfy the demand of experimrnts,while composite technology could combine multiple materials differing significantly in properties with each unique performance.This thesis mainly designed and prepared various hybrid vesicles,to enhance the application in the fileds of molecule carrying,biomacromolecules releasing,dyes degradation,anti-microbial and catalysis.A DNA-based binary vesicle(DNAsomes)was prepared via self-assembly of DNA-poly(N-isopropylacryl amide)nanoconjugates by water-in-oil Pickering Emulsion method.And this constructed capsule showed a good ability of carrying small molecules and protein release controlling.The capsule membrane was composed of PNIPAAm chains(a hydrophobic part)and DNA(a hydrophilic part)with intermolecular disulfide linkage between these chains,which was responsible for the reduction-sensitivity.The structure and morphology of capsules were characteried by scanning electron microscopy(SEM),UV-vis,Transmission electron microscopy(TEM),circular dichroism(CD)and dynamic light scattering(DLS).The shape,size and“groove nest effect”allowed a versatile design of DNAsomes to be carriers with high complexity.Being an outstanding small molecules and biomacromolecules(like protein)carrier,the DNAsomes showed superior stability under extracellular conditions but rapid capsule dissociation and protein release in the reductive environments.The ternary vesicles,HPs-Ag,have been synthesized using BSA-AgNCs-PNIPAAm as building block via Pickering emulsion method.The hollow structure was confirmed by SEM.The HRTEM images and Mapping showed results the the AgNCs were loaded in the membrane.The size of HPs-Ag can be controlled by changing the concentration of BSA-AgNCs-PNIPAAm.The HPs-Ag had unique character of self-rehydration,means that HPs-Ag could recover spherical structure by adding water after completed dehydration.The existence of AgNCs in the membrane of HPs-Ag enhanced antibacterial effect and show potential in materials storage(like enzye).The ternary vesicles,HPs-Au,have been synthesized using BSA-AuNCs-PNIPAAm as building block via Pickering emulsion route.The morphology of vesicles was investigated by UV-vis,SEM,TEM and DLS techniques.HPs-Au not noly had the character of phortoluminescence and self-rehydration,but also made catalysis perfoemace by AuNCs or loading other enzymes.When the same concentraton of lipase was loaded in the membrane showed 3 times higher catalytic efficiency than that encapsuled in HPs-Au.Due to the reason that Au-S bound would be broken under redox(H2O2)environment,the membrane permeability would changed from 20kDa to 55Kda.Moreover,the catalytic efficiency by ALP would increased 4 times than before adding H2O2.the unique redox-responsive HPs have potential applications in biocatalytic reaction,drug delivery,and materials as well as in bioscience.The ternary vesicles,AuNPs@vesicles,have been synthesized using BSA-PNIPAAm-AuNPs as building block via Pickering emulsion method.The morphology of vesicles was investigated by UV-vis,SEM,TEM and DLS measurements.This excellent microstructure leads to higher reduction efficiency of4?nitrophenol and more effect recycle time compared with AuNPs.Futhermore,laccase was encapsuled into the AuNPs@vesicles and also showed high efficiency in the reduction of congo red.The possible mechanisms of reduction of 4?nitrophenol and dye decolouration(congo red)was proposed.