Polymersomes Prepared from Thermoresponsive Fluorescent Protein–Polymer Bioconjugates: Capture of and Report on Drug and Protein Payloads

Abstract

Polymersomes provide a good platform for targeted drug delivery and the creation of complex (bio)catalytically active systems for research in synthetic biology. To realize these applications requires both spatial control over the encapsulation components in these polymersomes and a means to report where the components are in the polymersomes. To address these twin challenges, we synthesized the protein-polymer bioconjugate PNIPAM-b-amilFP497 composed of thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) and a green-fluorescent protein variant (amilFP497). Above 37 °C, this bioconjugate forms polymersomes that can (co-)encapsulate the fluorescent drug doxorubicin and the fluorescent light-harvesting protein phycoerythrin 545 (PE545). Using fluorescence lifetime imaging microscopy and Förster resonance energy transfer (FLIM-FRET), we can distinguish the co-encapsulated PE545 protein inside the polymersome membrane while doxorubicin is found both in the polymersome core and membrane.

NIR Laser-Responsive PNIPAM and Gold Nanorod Composites for the Engineering of Thermally Reactive Drug Delivery Nanomedicine

“…The structure of the synthesized polymer was also confirmed by 1 H-NMR spectra ( Figure A1). When comparing the spectra for PNIPAM and PNIPAM-SH, it can be seen that the peak is lower for PNIPAM-SH at 0.84-0.87 ppm due to the loss of -CH3 protons from the trithiocarbonate group via aminolysis [41,42]. As described above, the removal of the trithiocarbonate groups from PNIPAM using ethanolamine leads to the formation of disulfide bonds, thus increasing the molecular weight.…”

Photochemistry for Well‐Defined Polymers in Aqueous Media: From Fundamentals to Polymer Nanoparticles to Bioconjugates

“…This area of research has attracted interest due to potential applications, biocompatibility, and degradability of protein nanoparticles . Traditionally, these nanoparticles are formed by the conjugation of hydrophobic polymers to hydrophilic proteins to induce direct self‐assembly to form spheres, worms, or vesicles in aqueous solution . Huang and co‐workers used site‐specific modified BSA as a star macro‐RAFT in aqueous media and subsequently grew HPMA polymer chains, utilizing a “grafting‐from” approach, as seen in Scheme …”

Insights on the Structure, Molecular Weight and Activity of an Antibacterial Protein–Polymer Hybrid

“…On the other hand, introducing proteins into polymeric materials provides enhanced biocompatibility and biological functions. Hybrids indeed have found applications in biomolecular delivery, therapeutics, and antibacterial materials …”

“…Hybrids indeed have found applications in biomolecular delivery, [19,20] therapeutics, [2,16,[21][22][23][24] and antibacterial materials. [25][26][27] In spite of the (potentially)o utstanding properties, the hybrid bioactivity is often seriously reduced upon the conjugation with polymers. Such activity loss limits the broader appli-cation and furtherd evelopment of hybridized biomaterials.…”