Preparation And Study On Coumarin-based Light Trigger Photocontrolled Drug Delivery System

There are many drawbacks for the traditional systemic drug delivery, for instance:small molecular drugs cycling in vivo are likely to be enzymatic degraded and and can not give full paly to the efficacy; The simple small molecular drugs are non-targeted, which would induce side-effects to the normal organization except killing the diseased tissue. In order to overcome these shortcomings and improve the efficiency of drug treatment, stimuli-responsive controlled drug delivery systems are proposed. Based on the stimuli ways, they generally can be divided into light, electro, magnetic, thermal, and pH-responsive controlled drug release systems. Among these, photocontrolled drug release has become a hotspot in recent years because light has remote control properties that can targeted control drug release at the diseased tissues by regulating the illumination conditions including wavelength, intensity, and time. Moreover, in order to reduce the toxicity of drugs, increase the dose of drug to be transported, prevent drugs from premature metabolizability and control the distribution of drugs in the organization, biocompatible drug carriers (biocompatible superior polymer materials, nanoparticles and nanocomposites, etc.) should be selected to upload the phototrigger-activated prodrugs. Therefore, in this paper, PEG-modified chitosan and mesoporous silica were selected as the carriers to chemical conjugate with the phototrigger-activated prodrug. Finally, a new photocontrolled drug release system was constructed and its corresponding properties were studied.Recently, chitosan has become the hot material as carrier in the field of drug delivery system due to its outstanding physical, chemical and biocompatible properties. In the first part of this paper, a novel photocontrolled chitosan hydrogel drug delivery system was prepared and studied. In this system, the antinflammatory drug naproxen was conjugated with superior photo-responsive protected group, 7-amino-4-hydroxymethylcoumarin, by the esterification to form photosensitive prodrug. Then the produg was further conjugated with poly(ethylene glycol methyl ether) grafted chitosan backbone to form the final photocontrolled drug release hydrogel system. Under the irradiation of specific wavelength light, the system can release naproxen to realize the controlled drug release at any desired times and spots. In the second part of this paper, another excellent photocontrolled nano-drug delivery system was constructed based on the the biocompatible mesoporous silica as a drug carrier and 4-(hydroxymethyl)-7-aminocoumarin as a bridge to connect with the anti-cancer drug chlorambucil and the carrier.