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Myocardial Infarction (MI) is a leading cause of death worldwide. Metabolic modulation is a promising therapeutic approach to prevent adverse remodeling after MI. However, whether material‐derived cues can treat MI through metabolic regulation is mainly unexplored. Herein, a Cu2+ loaded casein microgel (CuCMG) aiming to rescue the pathological intramyocardial metabolism for MI amelioration is developed. Cu2+ is an important ion factor involved in metabolic pathways, and intracardiac copper drain is observed after MI. It is thus speculated that intramyocardial supplementation of Cu2+ can rescue myocardial metabolism. Casein, a milk‐derived protein, is screened out as Cu2+ carrier through molecular‐docking based on Cu2+ loading capacity and accessibility. CuCMGs notably attenuate MI‐induced cardiac dysfunction and maladaptive remodeling, accompanied by increased angiogenesis. The results from unbiased transcriptome profiling and oxidative phosphorylation analyses support the hypothesis that CuCMG prominently rescued the metabolic homeostasis of myocardium after MI. These findings enhance the understanding of the design and application of metabolic‐modulating biomaterials for ischemic cardiomyopathy therapy. [ABSTRACT FROM AUTHOR]

Single-nanoparticle detection has received tremendous interest due to its significance in fundamental physics and biological applications. Here, we demonstrate an optical nanofibre-enabled microfluidic sensor for the detection and sizing of nanoparticles. Benefitting from the strong evanescent field outside the nanofibre, a nanoparticle close to the nanofibre can scatter a portion of the field energy to the environment, resulting in a decrease in the transmitted intensity of the nanofibre. On the other hand, the narrow and shallow microfluidic channel provides a femtoliter-scale detection region, making nanoparticles flow through the detection region one by one. By real-time monitoring of the transmitted intensity of the nanofibre, the detection of a single polystyrene (PS) nanoparticle as small as 100 nm in diameter and exosomes in solution is realised. Based on a statistical analysis, the mean scattering signal is related to the size of the nanoparticle. Experimentally, a mixture of nanoparticles of different diameters (200, 500, and 1000 nm) in solution is identified. To demonstrate its potential in biological applications, high-throughput counting of yeasts using a pair of microchannels and dual-wavelength detection of fluorescently labelled nanoparticles are realised. We believe that the developed nanoparticle sensor holds great potential for the multiplexed and rapid sensing of diverse viruses. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to examine the effect of a three-step approach that utilizes the application of adipose tissue-derived mesenchymal stem cells (AD-MSCs), encapsulation, and pulsed focused ultrasound (pFUS) to help the engraftment and function of transplanted islets. Methods: In step 1, islets were co-cultured with AD-MSCs to form a coating of AD-MSCs on islets: here, AD-MSCs had a cytoprotective effect on islets; in step 2, islets coated with AD-MSCs were conformally encapsulated in a thin layer of alginate using a co-axial air-flow method: here, the capsule enabled AD-MSCs to be in close proximity to islets; in step 3, encapsulated islets coated with AD-MSCs were treated with pFUS: here, pFUS enhanced the secretion of insulin from islets as well as stimulated the cytoprotective effect of AD-MSCs. Results: Our approach was shown to prevent islet death and preserve islet functionality in vitro. When 175 syngeneic encapsulated islets coated with AD-MSCs were transplanted beneath the kidney capsule of diabetic mice, and then followed every 3 days with pFUS treatment until day 12 post-transplantation, we saw a significant improvement in islet function with diabetic animals re-establishing glycemic control over the course of our study (i.e., 30 days). In addition, our approach was able to enhance islet engraftment by facilitating their revascularization and reducing inflammation. Conclusions: This study demonstrates that our clinically translatable three-step approach is able to improve the function and viability of transplanted islets. [ABSTRACT FROM AUTHOR]

A dual responsive surface is constructed on hydrophilic polymer brushes to modulate cell migration ability on demand. The responsibility is based on the dynamic host–guest interaction between β‐CD and azobenzene. Both competitive guest molecules and UV radiation are able to release azobenzene‐REDV from the substrate, weakening the cell–substrate interaction and modulating the cell migration rate. [ABSTRACT FROM AUTHOR]

Selectiveenhancement of directional migration of endotheliocytes(ECs) over vascular smooth muscle cells (SMCs) plays a significantrole for the fast endothelialization of blood-contacting implants,in particular for the antirestenosis of vascular stents. Herein, acomplementary density gradient of poly(2-hydroxyethyl methacrylate)(PHEMA) brushes and YIGSR peptide, a sequence specifically improvingthe mobility of ECs, was fabricated using a dynamically controlledreaction process. The gradients were visualized by fluorescent labelingand further quantified by X-ray photoelectron spectrometry (XPS) andquartz crystal microbalance with dissipation (QCM-d). The ECs exhibitedpreferential orientation and enhanced directional migration behavioron the gradient surface toward the region of lower PHEMA density andhigher YIGSR density. The migration rate of the ECs was significantlyenhanced to 5-fold, whereas the mobility of SMCs was not significantlyinfluenced, leading to faster migration of ECs than SMCs. Therefore,the success of the complementary gradient relies on the appropriateinterplay between the PHEMA brushes and the cell-specific ligands,enabling the selective guidance of EC migration. [ABSTRACT FROM AUTHOR]