Synthesis And Biological Application Of PH-responsive Polymers

1.In this chapter,oligoethylene glycol methacrylate(OEGMA),diethylamine ethyl methacrylate(DEAEMA)and orthoester structural units are used to construct a lightly cross-linked branched copolymer(BP).Polymer nanoparticles could be prepared directly from the BPs after dissolving the polymer in water,which exhibited dual p H-responsiveness : Nanoparticles were stable at p H 7.0,and underwent an expanding-to-decompose process when p H dropped down to 5.5.Subsequently,taking hydrophobic rheum emodin(RE)as a model drug,drug loading/release properties studies were carried out,and the loading rate reached 35.2%.At p H 5.5,the drug release rate reached 87% after 48 hours,and at p H 7.0,the drug nanoparticles were relatively stable,and only 21% of RE was released in 48 hours.This study provides a new ieda for the preparation and application of new stimulus-response nano-drug-loaded materials.2.The antibacterial performance could be effectively improve through applying targeting antibacterial materials.In this chapter,reduction method is used to synthesize uniform p H-responsive Ag nanoclusters(POEC-Ag).When exposed to the bacterial microacid environment,the regular silver nanoclusters will disintegrate and reassemble to ununiform Ag nanoparticle aggregates(POEC-Ag).This p H-responsive re-assembly greatly improves the antibacterial properties of POEC-Ag against methicillin-resistant Staphylococcus aureus(MRSA)and E.coli.The minimum MIC and MBC for MRSA were 4 and 32 ?g/m L,and the MIC and MBC for E.coli were 8 and 32 ?g/m L,respectively.In vivo skin wound healing experiments show that POEC-Ag can be used as dressings to promote skin wound healing after MRSA infection.The development of responsive POEC-Ag provides new materials and research strategies for targeted antibacteria.