Topic: Biomedical clay nanocomposites with sustained drug release
Speaker: Prof. Yuri Lvov, Louisiana Tech University, America
Time: 9:00 a.m., Sep. 6, 2016
Venue: Conference Room 331, Building 25, Wushan Campus
Abstract:
Halloysite alumosilicate nanotubes with a 15 nm lumen, 50 nm external diameter, and length of 1-1.5 µm have been developed as an entrapment system for loading, storage, and controlled release of chemical agents (anticorrosion, flame-retardancy, biocides, drugs and proteins). Studies to enable the control of release rates from hours to days and months are being undertaken. By the formation of nanoshells over the nanotubes or by creation of smart caps at the tube ends it is possible to extend release rate. Halloysite forms stable aqueous colloids and is well admixable with polar and low polar plastics. Protective halloysite coatings and a self-healing approach have been tested for repair mechanisms through response activation by external impacts. Doping loaded clay nanotubes into polymeric matrix (polyurethane, polypropylene, siloxane, epoxy, etc.) provides sustained inhibitors’ release and this ceramic “skeleton” is enhancing the composite strength. Doping clay nanotubes into paint at 3-5 wt. % provides sustained release of anticorrosion agents resulting in 2-times longer metal protection as well as in 50-100 % increase in the coating strength and adhesivity. As well, double in flame-retardancy was reached. Biocompatible halloysite nanotubes allow for 10 wt. % loading with drugs and proteins preserving their activity and providing 10-50 hrs release time. Halloysite nanotubes are available in thousands of tons, and remain sophisticated and novel nanomaterials which can be used as smart nano-containers. Halloysite is also a green material and due to the fact that it is a natural product will not add risk to the environment.