Pnipaam-based Biomineralized Micro/Nano Hybrid Materials Preparation And Smart Drug Delivery

In this research, PNIPAAm/CaHPO4and PNIPAAm/CaCO3micro/nano hybrid materials were prepared via emulsion polymerization and mineralization. Two kinds of polyelectrolyte, polyacrylic acid (PAA) and sodium polystyrene sulfonate (PSS), were employed as crystal growth additive to control the structure and morphology of the hybrid materials. The structure of micro/nano hybrid materials was charactered by FT-IR, TQ XRD, SEM, TEM and UV-vis. The results demonstrated that the inorganic component obviously improved the stability and strength of PNIPAAm nanogels. The swelling ratio and the drug release behaviour using VB2as model drug revealed that the prepared hybrid materials were pH-and thermo-responsiveness. In addition, the release profile was sustained with the introduction of inorganic microparticles, indicating that the inorganic microparticles could hinder the permeability of the encapsulated drug and reduce the drug release effectively. There are two major sections in this thesis:In the first part of the thesis, PNIPAAm/CaHP04hybrid materials were prepared via minerlazation method. PAA was used as the crystal growth additive to control the size and morphology of CaHPO4nanocrystallines. FT-IR, XRD, SEM, TEM, TG and Zeta potential were employed to demonstrate the structure of PNIPAAm/CaHP04hybrid materials. The results proved that the size of the CaHPO4crystallines was decreased by the introduction of PAA, the CaHPO4crystallines promoted the dispersivity and stability of the prepared hybrid materials. Drug release results demonstrated that the hybrid materials were pH-and thermo-responsiveness. In addition, CaHPO4microcrystallines could hinder the permeation of the encapsulated drug and reduce the drug release effectively.In the second part of the thesis, PNIPAAm/CaCO3hybrid materials were prepared via mineralization method. PAA and PSS were empolyed as the crystal growth additive, respectively. FT-IR、XRD、SEM、FESEM、TG、BET and UV-vis were performed to identify the structure of the hybrid materials. The results demonstrated that PSS could accelerate the transformation of CaCO3microcrystals from calcite to vaterite. PNIPAAm nanogels were adhered on the surface of vaterite CaCO2microcrystals, resulting relatively tight combination between PNIPAAm nanogels and CaCO3microcrystals. Moreover, BET and drug loading efficiency results demonstrated that the surface area and drug loading efficiency of hybrid materials using PSS as crystal growth additive were higher than that of pure PNIPAAm nanogels. Drug release results demonstrated that the hybrid materials were pH-and thermo-responsiveness. Moreover, CaCO3microcrystallines could hinder the permeation of the encapsulated drug and reduce the drug release effectively.