S Thayumanavan

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Stimuli-responsive polymers are arguably the most widely considered systems for a variety of applications in biomedical arena. We report here a novel triple stimuli sensitive block copolymer assembly that responds to changes in temperature, pH and redox potential. Our block copolymer design constitutes an acid-sensitive THP-protected HEMA as the hydrophobic(More)
Exchange dynamics of lipophilic guest molecules, encapsulated in supramolecular nanoassemblies in aqueous solutions, have implications in evaluating the stability of drug delivery vehicles. This is because exchange dynamics is related to the propensity of a nanocarrier to be leaky. We describe a fluorescence resonance energy transfer (FRET) based method to(More)
We report here on a new amphiphilic homopolymer that binds noncovalently to proteins. This polymer not only binds to the target protein chymotrypsin with submicromolar affinity but also stabilizes the native structure of the protein. Since the polymer-protein binding process is based on electrostatic interaction, the bound protein can be released from the(More)
Nonconjugated dendrimers, which are capable of funneling energy from the periphery to the core followed by a charge-transfer process from the core to the periphery, have been synthesized. The energy and electron donors involve a diarylaminopyrene unit and are incorporated at the periphery of these dendrimers. The energy and electron acceptor is at the core(More)
A simple strategy for pattern recognition of proteins through micellar disassembly is introduced. Five different noncovalently assembled receptors have been generated, and the disassembly was studied by monitoring the encapsulated dye release in response to five different proteins. The disassembly induced fluorescence change of the guest molecule produces(More)
Oligo(ethylene glycol)-decorated supramolecular assemblies have been of great interest due to their charge-neutral character and thus their propensity to avoid nonspecific interactions. These systems are known to exhibit a macroscopic temperature-sensitive transition, where the assembly phase-separates from the aqueous phase at higher temperatures. While(More)
In this review, we outline examples that illustrate the design criteria for achieving macromolecular assemblies that incorporate a combination of two or more chemical, physical or biological stimuli-responsive components. Progress in both fundamental investigation into the phase transformations of these polymers in response to multiple stimuli and their(More)
A mild deprotection strategy for allyl ethers under basic conditions in the presence of a palladium catalyst is described. Under these conditions, aryl allyl ethers can be cleaved selectively in the presence of alkyl allyl ethers. These conditions are also effective in the deprotection of allyloxycarbonyl groups. The utility of the current methodology in(More)
Influence of Hofmeister ions has been investigated on the size and guest encapsulation stability of a polymeric nanogel. While variations in macroscopic phase transitions have been observed in response to the presence of salts, changes in the size and host-guest behavior of polymeric aggregates in the presence of salts have not been explored in any detail.(More)
Polymer-based nanoassemblies have emerged as viable platforms for the encapsulation and delivery of lipophilic molecules. Among the criteria that such carriers must meet, if they are to be effective, are the abilities to efficiently solubilize lipophilic guests within an assembled scaffold and to stably encapsulate the molecular cargo until desired release(More)