Controlled Drug Delivery

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A delivery system refers to strategies for transporting a therapeutic substance in the body as needed to safely achieve its desired therapeutic effect. These technologies are able to modify release behavior, absorption, distribution and eradication of the system for improving efficacy and safety of a therapeutic agent. The group has successfully developed controlled and/or targeted delivery systems that can be administrated through the preferred non-invasive peroral, topical, transmucosal and inhalation routes. Our group is now working on the development of advanced delivery systems in which the substance is only active in the target area of the human body and is released over a period of time in a controlled manner. The challenge here is to design a system that can avoid the host's defense mechanisms and circulate to its intended site of action.

Highlights

  • A myriad of pathologies affect the gastrointestinal tract, citing this affected area as a significant target for therapeutic intervention. One group of therapeutic agents, antisense and oligonucleotides and small interfering RNAs, offer a promising platform for treating a wide variety of diseases ranging from cancer to auto-immune diseases. Current delivery methods are carried out either systemically or locally into diseased areas, both of which involve needles. The challenge in orally administering this type of treatment lies in the complications that arise due to the vast environmental extremes found within the gastrointestinal tract, owing to the fact that, as the drug travels down the gastrointestinal tract, it is subjected to pH changes and interactions with bacteria and a variety of digestive and protective enzymes including proteases, DNAses, and RNAses. We are working on the overcoming these challenges to allow the practical application of these drugs as a priority that moved us to a multitude of research in the chemical, biological, and material sciences.

  • The potential health benefits of natural surfactants, such as vitamin E (d-α-tocopheryl polyethylene glycol 1000 succinate, TPGS), in curing neurological symptoms have been studied. Therefore, natural surfactant-containing nanoparticulate carriers for delivery of drugs to different site specific parts of the body are useful from different points of view. Herein, in order to obtain desired surface morphology and particle sizes of nanoparticles and high emulsifying effects, we are working on the optimization of different nanoparticles as potential carriers with neurological abilities for the delivery of drugs to the body. Our primary results indicate that the amount of surfactant could have a direct effect on the average particle size and the distribution of particle diameters. It is important to find an optimum procedure for the use of therapeutic surfactants for achieving the most effective clinical effects.

  • Ultrasound-targeted microbubble destruction (UTMD) is a promising technique with an immense target-specific gene delivery potential deep inside the human body. In collaboration with Prof. Shimoda in Research Institute of National Center for Global Health and Medicine in Tokyo, we are developing innovative UTMD systems for various treatment applications. We have recently confirmed the potential of this technique for diabetic patients. This technology allows the genes to transfer specifically into the inefficient pancreas using ultrasound energy without viral vector utilization. We speculate that this idea and the advent of modern gene therapy techniques could result in significant future advances. Undoubtedly, this strategy needs further investigation and many critical questions have to be answered before it can be successfully advanced.