Self-immolative and biodegradable polymer: A smart and responsive nano-carrier, Biosensor, Signal en
Self-assembled nanostructures driven by solvophobic interactions of the constituent functional groups have been great interest because of their implications in a variety of areas including drug delivery, catalysis, and nanotechnology. Embedding stimuli responsive features within these amphiphilic aggregates endows the area with the so-called 'smart' nano-materials, which senses and responds to specific environmental cues. There are myriad of systems that have been designed to respond to internal chemical stimuli such as pH or redox variations, or external physical stimuli such as temperature, light or magnetic field. A third category of stimuli, which deserve significant attention involves biological stimuli. A largely unmet challenge involves development of systems that responds to non-enzymatic proteins, where by protein-ligand interactions are utilized for a supramolecular disassembly phenomenon. There have been only a few isolated efforts to address this issue. In addition to addressing a large class of proteins (non-enzymatic ones) that have not received much attention, strategies that utilize protein-ligand interactions as the driving force have additional advantages. For example, the ligand-protein interaction based strategies can be conveniently extended to enzymatic proteins also and therefore these strategies have the promise of being more general. To execute the above said idea, we are basically interested in polymers with biocompatible and biodegradable backbone like synthetic polypeptide and poly lactide.
Another class of polymer we are interested in is self-immolative polymer. The polymer backbone has very interesting degradation nature which made it very promising candidate in the field of drug delivery, signal enhancement and sensor applications. For self-immolative backbone we will be using polyurethane homopolymer. This kind of system is designed based on very interesting design philosophy. Polymer backbone has the architectures that empower the exploitation of neighboring-group interactions, 1,6-elimination, and decarboxylation reactions. The polymer is cleverly capped with a trigger group at the polymer chain end and the moment trigger group is removed whole polymer will collapse. This triggering effect can be compared with the fact of removal of a key stone from the arch, which will make the whole arch collapse.
