Unique diblock polyphosphoramidates (PPAs), with acid-labile phosphoramidate backbone linkages and alkyne side-chain functionalities, were developed as a versatile template for postpolymerization modifications, together with demonstration of their hydrolytic degradability as well as their aqueous assembly into functional nanoparticle morphologies. The introduction of acid-labile linkages along the polymer backbone led to rapid degradation of the polymer backbone dependent upon the environmental stimuli. Two oxazaphospholidine monomers, with one carrying alkyne functionality, were designed and synthesized to access well-defined diblock PPAs (PDI &lt; 1.2) <i>via</i> sequential organobase-catalyzed ring-opening polymerizations (ROPs) with pendant alkyne groups for efficient functionalizations through click chemistry. Kinetic studies of the sequential ROPs showed a linear relationship between the monomer conversion and the polymer molecular weight, indicating the controlled fashion during each polymerization. The resulting PPAs with different block ratios, were further assembled into a family of nanostructures with different sizes, morphologies. In addition, two classic click reactions, copper-catalyzed azide-alkyne dipolar cycloaddition (CuAAC) and thiol-yne addition reactions, were employed to manipulate the alkyne-containing block and to provide a variety of diblock PPAs, which could be utilized for further biomedical and other applications. The hydrolytic degradation of the PPAs was studied, revealing breakdown of the polymer backbone through cleavage of the phosphoramidate linkages under acidic conditions.

Functional polyphosphoramidates and nanostructures with acid-triggered backbone cleavage

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.