Abstract

Our project aims to construct a chain-reactive molecule-releasing system in a spontaneous manner. Delivering drugs at appropriate places and controlling the quantity of released drug is very important to develop effective DDS. Our system makes these possible.
The system consists of two sub-systems: “egg-type initiator” and “chain-reactive burst”.
The “egg-type initiator” releases trigger DNAs under a certain condition like warming up to body temperature. The trigger DNAs hybridize to aptamer DNAs on liposomes, and the hybridization causes liposomes collapse. The collapsed liposomes release drugs and new trigger stored inside. These processes are the “chain-reactive burst”, and achieve sequential and exponential release of drugs.
To realize the egg-type initiator, trigger DNAs and chelate compounds are encapsulated in temperature-sensitive liposomes, and the liposomes are encapsulated in alginate hydrogel. Increasing temperature disrupts the liposomes, and then chelate compounds inside the liposomes melt the gels. Collapse of liposomes is realized by rapid deformation of liposomes mediated by hybridization between trigger and aptamer DNAs.
Our system will propose a new place and quantity controlling system of drug release by liposome-based drug delivery systems.