Session: PMSE/POLY Poster Session:

In recent years, polymerization-induced self-assembly (PISA) has become a widely-utilized and efficient one-pot methodology to produce block copolymer nano-objects of controlled size, morphology and tunable properties at high concentrations (10−30% w/w). However, research toward bio-related nanomaterials produced by aqueous PISA is currently limited. This is mainly attributed to the elevated reaction temperatures required for most thermally initiated aqueous PISA formulations that can lead to denaturation of delicate biomolecules, such as proteins and enzymes. Recently, an increasing number of studies based on visible-light-initiated PISA (photo-PISA) at ambient temperatures have been reported, showing great promise in the development of novel materials of particular biotechnological and biomedical interest. Additionally, the design of facile and mild routes for the preparation of well-defined polymersomes by photo-PISA is of great interest as it allows for the development of cargo-loaded nanocarriers in a single synthetic step.
To this extent, we utilize aqueous RAFT-mediated photo-PISA as a platform for one-pot development of enzyme-loaded polymersomes with inherent size-selective permeability, enabling the encapsulated enzymes to remain catalytically active and function from within a confined domain. The ability of the functional polymersome nanoreactors to communicate via a cascade reaction is presented, while the reduction of antibody binding and proteolytic susceptibility in the case of therapeutic enzyme-loaded nanoreactors compared to the native enzyme is also demonstrated. On the basis of these findings, we then move toward tuning the membrane permeability of the prepared polymersomes either by altering the chemistry of the membrane to make it impermeable toward small molecules or by incorporating the hydrophobic channel-forming outer membrane protein F (OmpF) into the polymersomes via the aid of surfactants to enhance their permeability. This demonstration highlights the potential application of PISA for direct insertion of challenging hydrophilic or hydrophobic biomolecules into polymeric assemblies with tunable properties that could contribute significantly to the further development of biomembrane-mimicking protocells.

Jeffrey Foster

Oak Ridge National Laboratory Physical Sciences Directorate

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