Study On Drug Delivery Systems Of Visible And Near Infrared Light-sensitive O-nitrobenzyl Prodrugs

With the rapid development of modern biomedical technologies, more and more new drugs are needed. However, to develop a new drug is not very easy, it needs not only a lot of manpower and materials resources, but also time which usually takes years or even decades. So, it is a new route to use the traditional drugs by changing the drug's delivery systems. In these ways, the controlled drug release systems played important roles in the biomedical areas because of their abilities in improving drug efficacies and reducing the side effects in vivo.Through the non-physical contact mode with objects, light can achieve a two-dimensional interaction with objects in time and space. And the design and preparations of different kinds of photo-regulated drug delivery systems have attracted much attention recently. However, there are a lot of drawbacks to be solved in the using photo-sensitive groups in biomedicine, such as the low photocleavage efficiency and UV-responsive only. In this thesis, we designed and synthesized a new class of o-nitrobenzyl ether by enhancing the conjugation system and it maximum peak in UV-vis absorption red-shifted 20nm. And the anti-cancer drug, chlorambucil can be released upon irradiation by visible light. In addition, the photosensitive groups have a two-photon cross section of 20 GM at 800 nm, and the prodrugs could also be photoreleased by near infrared laser. We have studied the photochemical and photophysics properties of these visible and near-infrared light sensitive o-nitrobenzyl prodrugs.In the end, we have also designed and prepared chitosan nanoparticles drug delivery system with the same o-nitrobenzyl photosensitive group and polyethylene glycol modifications. The gained chitosan derivatives nanoparticles released hydrophobic drug model, Nile red, upon visible light irradiation.