The control of the branching in polyglycidols as semibranched alternatives to traditional polyglycidols is presented. The relative abundance of dendritic carbons is lowered by five-fold compared to hyperbranched polyglycidols. It is the first example of tailoring the branching in polyglycidol and creating protein-glycidol bioconjugates as alternatives to pegylated biostructures.

Active stresses are generated and transmitted throughout diverse F-actin architectures within the cell cytoskeleton, and drive essential behaviors of the cell, from cell division to migration. However, while the impact of F-actin architecture on the transmission of stress is well studied, the role of architecture on the ab initio generation of stresses remains less understood. Here, we assemble F-actin networks in vitro, whose architectures are varied from branched to bundled through F-actin nucleation via Arp2/3 and the formin mDia1. Within these architectures, we track the motions of embedded myosin thick filaments and connect them to the extent of F-actin network deformation. While mDia1-nucleated networks facilitate the accumulation of stress and drive contractility through enhanced actomyosin sliding, branched networks prevent stress accumulation through the inhibited processivity of thick filaments. The reduction in processivity is due to a decrease in translational and rotational motions constrained by the local density and geometry of F-actin.

The specificity of DNA hybridization allows for the modular design of 2D and 3D shapes with wide-ranging applications including sensors, actuators, and even logic devices. The inherent biocompatibility of DNA and the ability to produce monodisperse structures of controlled shape and size make DNA nanostructures of interest as potential drug and gene delivery vehicles. In this review, we discuss several new approaches for the assembly of DNA nanostructures, advances in the modeling of these structures, and we highlight recent studies on the use of DNA nanotechnology for therapeutic applications such as drug delivery in tumor models.

Recently there have been notable synthetic successes in supramolecular polymerization. By contrast, it has long been known that DNA can undergo supramolecular polymerization (concatemerization). Concatemerization is a step-like polymerization and consequently suffers from broad molecular weight distributions and generally undesirable cyclization reactions. Here we demonstrate that another supramolecular polymerization of DNA, hybridization chain reaction (HCR), is in fact a living polymerization. After consumption of initial monomer, the polymerization can be continued with further addition of monomer, and the molecular weight can be varied by the ratio of monomer to initiator. In contrast to concatemerization, HCR produces polymers with narrow dispersity while avoiding cyclization. Identification of the living character of this supramolecular polymerization presents new opportunities in structural DNA nanotechnology and molecular biology.

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