The strength of associations between ultrasound measures of upper limb muscle morphology and isometric muscle strength: An exploratory study.

Introduction/aims: Assessing upper limb muscle strength is important for understanding health outcomes, such as daily function and mortality. Ultrasound (US) is increasingly used to evaluate muscle health, but the relationship between its measures of morphology and isometric strength has not been thoroughly explored in upper limb muscles. The aim of this study was to evaluate the associations between US morphological measures and isometric strength in functionally relevant upper limb muscles in healthy adults.

Branching in poly(amine-co-ester) polyplexes impacts mRNA transfection.

Branching is a key structural parameter of polymers, which can have profound impacts on physicochemical properties. It has been demonstrated that branching is a modulating factor for mRNA delivery and transfection using delivery vehicles built from cationic polymers, but the influence of polymer branching on mRNA delivery remains relatively underexplored compared to other polymer features such as monomer composition, hydrophobicity, pKa, or the type of terminal group. In this study, we examined the impact of branching on the physicochemical properties of poly(amine-co-esters) (PACE) and their efficiency in mRNA transfection in vivo and in vitro under various conditions.

Modifying the Backbone Chemistry of PEG-Based Bottlebrush Block Copolymers for the Formation of Long-Circulating Nanoparticles.

Nanoparticle physicochemical properties have received great attention in optimizing the performance of nanoparticles for biomedical applications. For example, surface functionalization with small molecules or linear hydrophilic polymers is commonly used to tune the interaction of nanoparticles with proteins and cells. However, it is challenging to control the location of functional groups within the shell for conventional nanoparticles.

Glycocalyx-Mimicking Nanoparticles with Differential Organ Selectivity for Drug Delivery and Therapy.

Organ-selective drug delivery is expected to maximize the efficacy of various therapeutic modalities while minimizing their systemic toxicity. Lipid nanoparticles and polymersomes can direct the organ-selective delivery of mRNAs or gene editing machineries, but their delivery is limited to mostly liver, spleen, and lung. A platform that enables delivery to these and other target organs is urgently needed.

Nanoscale Surface Topography of Polyethylene Glycol-Coated Nanoparticles Composed of Bottlebrush Block Copolymers Prolongs Systemic Circulation and Enhances Tumor Uptake.

Improving the performance of nanocarriers remains a major challenge in the clinical translation of nanomedicine. Efforts to optimize nanoparticle formulations typically rely on tuning the surface density and thickness of stealthy polymer coatings, such as poly(ethylene glycol) (PEG). Here, we show that modulating the surface topography of PEGylated nanoparticles using bottlebrush block copolymers (BBCPs) significantly enhances circulation and tumor accumulation, providing an alternative strategy to improve nanoparticle coatings.