Cell Engineering with Functional Poly(oxanorbornene) Block Copolymers

Grafting-from Synthesis of Plant-Polynorbornene Biohybrid Materials

Plants, essential for food, oxygen, and economic stability, are under threat from human activities, biotic threats, and climate change, requiring rapid technological advancements for protection. Biohybrid systems, merging synthetic macromolecules with biological components, have provided improvement to biological systems in the past, namely, in the biomedical arena, motivating an opportunity to enhance plant well-being. Nevertheless, strategies for plant biohybrid systems remain limited. In this study, we present a method using grafting-from ring-opening metathesis polymerization (ROMP) under physiological conditions to integrate norbornene-derived polymers into live plants by spray coating. The approach involves creating biological macroinitiators on leaf surfaces, which enable subsequent polymerization of norbornene-derived monomers. Characterization techniques, including FTIR spectroscopy, SEM EDS imaging, ICP-MS, nanoindentation, and XPS, confirmed the presence and characterized the properties of the polymeric layers on leaves. The demonstrated modifiability and biocompatibility could offer the potential to maintain plant health in various applications, including the development of thermal barriers, biosensors, and crop protection layers.

Polymer Chemistry for Haptics, Soft Robotics, and Human-Machine Interfaces

Progress in the field of soft devices-i.e., haptics, robotics, and human-machine interfaces (HRHMIs)-has its basis in the science of polymeric materials and chemical synthesis. However, in examining the relevant literature, we find that most developments have been enabled by off-the-shelf materials used either alone or as components of physical blends and composites. In this Progress Report, we take the position that a greater awareness of the capabilities of synthetic chemistry will accelerate the capabilities of HRHMIs. Conversely, an awareness of the applications sought by engineers working in this area may spark the development of new molecular designs and synthetic methodologies by chemists. We highlight several applications of active, stimuli-responsive polymers, which have demonstrated or shown potential use in HRHMIs. These materials share the fact that they are products of state-of-the-art synthetic techniques. The Progress Report is thus organized by the chemistry by which the materials were synthesized, including controlled radical polymerization, metal-mediated cross-coupling polymerization, ring-opening polymerization, various strategies for crosslinking, and hybrid approaches. These methods can afford polymers with multiple properties (i.e. conductivity, stimuli-responsiveness, self-healing and degradable abilities, biocompatibility, adhesiveness, and mechanical robustness) that are of great interest to scientists and engineers concerned with soft devices for human interaction.

Proapoptotic Peptide Brush Polymer Nanoparticles via Photoinitiated Polymerization-Induced Self-Assembly

Herein, we report the photoinitiated polymerization-induced self-assembly (photo-PISA) of spherical micelles consisting of proapoptotic peptide-polymer amphiphiles. The one-pot synthetic approach yielded micellar nanoparticles at high concentrations and at scale (150 mg mL-1 ) with tunable peptide loadings up to 48 wt. %. The size of the micellar nanoparticles was tuned by varying the lengths of hydrophobic and hydrophilic building blocks. Critically, the peptide-functionalized nanoparticles imbued the proapoptotic "KLA" peptides (amino acid sequence: KLAKLAKKLAKLAK) with two key properties otherwise not inherent to the sequence: 1) proteolytic resistance compared to the oligopeptide alone; 2) significantly enhanced cell uptake by multivalent display of KLA peptide brushes. The result was demonstrated improved apoptosis efficiency in HeLa cells. These results highlight the potential of photo-PISA in the large-scale synthesis of functional, proteolytically resistant peptide-polymer conjugates for intracellular delivery.