Preparation And Study Of PH And Magnetic Sensitive Nanocomposite Hydrogels

Hydrogels have pervaded our everyday life in a variety of forms. The wet soft solids that we encounter in the form of commercial products such as soap, shampoo, toothpaste, hair gel and other cosmetics, as well as contact lenses and gel pens etc. are all hydrogels derived from polymeric compounds. Polymer hydrogels have been known for centuries and applications in fields as diverse as food, medicine, materials science, cosmetics, pharmacology. It is known that hydrogels show good advantages as biomedical materials. Many hydrogels obtained from natural polymers display good biocompatibility and are used for drug controlled delivery systems. However, the flaws, including weak mechanical properties and burst release of the drugs, are inevitable when pristine biopolymers are used as carriers. Considering that the weak mechanical properties and burst release of drugs are mainly due to the characteristics of the biopolymers, the weak interaction between the biopolymers and the drugs, and the quick disintegration of the biopolymer carries during the release process. In order to overcome these shortcomings, we prepared a series of novel biopolymer/nanomaterial composites.(1) In order to find a new way to control release of drug, a series of novel pH-sensitive konjac glucomannan/sodium alginate (KGM/SA) and konjac glucomannan/sodium alginate/graphene oxide (KGM/SA/GO) hydrogels were prepared, with GO as a drug-binding effector for anticancer drug loading and release. The effects of component ratio and pH on the swelling properties of hydrogels were investigated. From results, at pH1.2, the release amount of5-Fluorouracil (5-FU) incorporated into the KGM/SA/GO-3hydrogels was about38.02%within6h, while this value approached to84.19%via12h at pH6.8. Therefore, GO is a promising drug-binding effector for hydrogel functionalization in drug delivery.(2) In order to promote hydrogels functional properties, we designed a new way to prepare a series of novel pH and magnetic-sensitive nanocomposite hydrogels:firstly, the biocompatible sodium alginate was crosslinked by Fe2+and Fe3+; then, the magnetic-sensitive nanocomposite hydrogels were prepared in situ synthesis. The magnetic hydrogels were characterized by using techniques such as fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and thermogravimetric analysis (TGA). The swelling analysis and controlled drug release of the samples were evaluated. The results indicated that the prepared hydrogels showed good magnetic and pH sensitivity. And by changing the content of Fe2+and Fe3+, the swelling behavior of hydrogels and the speed of drug release could be controlled.