0428同步年報-2021-全

086 ACTIVITY REPORT 2021 Fig. 1 : (a) Fe K-edge derivative XANES spectra of Fe 3 O 4 , IONP, MGNS and MGNS-nanogel. (b) Fe K-edge EXAFS Fourier- transformed spectra of Fe 3 O 4 , IONP, MGNS and MGNS- nanogel. [Reproduced from Ref. 6] Doxorubicin-Loaded Thermo- and pH-Tunable Carriers for Targeted Drug Delivery to Liver Cancer Cells in Vitro The thermo- and pH-dependent DOX carriers based on MGNS, functionalized with a PNIPAM and PEI nanogel that targets liver cancer cells, were formulated and showed a high potential for microenvironment stimulus-prompted drug delivery and suppression of cancer cells. S mart drug-delivery biomaterials that are triggered with specific stimuli, including temperature, pH and enzymatic activity, have recently been formulated. The stimulus-responsive properties of these biomaterials can offer an improved delivery of drugs to the targeted tumor sites when applied in anticancer drug delivery. 1,2 Stimulus-dependent biomaterials are promising candidates for precise control of drug delivery to targeted sites. These materials undergo rapid tunable structural changes prompted by exterior stimuli in the surrounding changes of the samples were measured at temperatures 25, 37 and 42 °C. Kuen-Song Lin (Yuan Ze University) and his group thoroughly examined the nature of the iron products using the XANES technique to obtain information related to the electronic configuration, stereochemistry and oxidation states of Fe atoms in the samples. 2,6 The XANES results environment, offering a well-controlled drug release. Among stimulus-dependent biomaterials, thermo-responsive biomaterials offer exciting prospects for the controlled release of anticancer drugs, precisely to the cancer cells, whereas decreasing adverse effects on other organs. 3,4 The interior applied temperature can hence prompt the release of drugs from such biomaterials, thereby controlling the release pattern or required dosage of drugs in the targeted location. Attention should be paid to thermo-responsive nanogels, which transit because of temperature changes on adjusting their physiochemical and colloidal properties, and exhibit a phase-transition temperature, namely the lower critical solution temperature (LCST). In an aqueous solution, thermo-responsive polymers undergo rapid and changeable structural transitions from a swollen to a collapsed state, which leads to an on–off detachment of drug molecules due to temperature. 5 Moreover, pH-dependent biomaterials have been developed to release drugs in acidic tumor environments. Polymeric micelles have been incorporated with pH-sensitive components that transit to a hydrophilic state under acidic pH, causing the micelles to disassemble and to trigger the release of drugs. These pH-responsive biomaterials undergo a transition once delivered to acidic sites or in acidic tumor microenvironments. The analyses of X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectra were performed to understand the fine structure and the Fe atomic arrangement in terms of bond distance and co-ordination number. The XANES and EXAFS experiments were implemented at wiggler beamline TLS 17C1 . Small-angle neutron scattering (SANS) experiments were undertaken on BILBY scattering equipment (OPAL research reactor) at Australian Nuclear Science and Technology Organisation (ANSTO, Australia). The structural