Mixing End Groups in Thiol-Ene/Yne Reactions as a Simple Approach toward Multienzyme-Responsive Polymeric Amphiphiles

Abstract

Taking advantage of the high fidelity of thiol-ene and thiol-yne chemistries, we used mixtures of thiols to prepare degradable PEG-dendron amphiphiles functionalized with two different types of enzymatically cleavable end groups. By tuning the feed ratios of the two thiols, we achieved mixtures of hybrids with statistically different ratios of end groups. Studies of the disassembly of statistically mixed hybrids showed that these amphiphiles have higher degrees of response when incubated with each of the activating enzymes, whereas a greater degree of selectivity was observed for a control mixture of two distinct amphiphiles, which required the presence of both types of enzyme to undergo complete disassembly. The potential to introduce different end groups by using a mixture of thiols in an efficient single thiol-ene or thiol-yne step opens the way for simple modification of various ene- or yne-containing polymers and tailoring of their structural and functional properties.