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Active targeting strategies aimed at improving drug homing while reducing systemic toxicity are widely being pursued in the growing field of nanomedicine. While they can be effective, these approaches often require the identification of cell-specific targets and in-depth knowledge of receptor binding interactions. More recently, there has been significant interest in biomimetic nanoformulations capable of replicating the properties of naturally occurring systems. In particular, the advent of cell membrane coating nanotechnology has enabled researchers to leverage the inherent tropisms displayed by living cells, bypassing many of the challenges associated with traditional bottom-up nanoengineering. In this work, we report on a biomimetic organotropic nanodelivery system for localizing therapeutic payloads to the lungs. Metastatic breast cancer exosomes, which are lung tropic due to their unique surface marker expression profile, are used to coat nanoparticle cores loaded with the anti-inflammatory drug dexamethasone. In vivo, these nanoparticles demonstrate enhanced accumulation in lung tissue and significantly reduce proinflammatory cytokine burden in a lung inflammation model. Overall, this work highlights the potential of using biomimetic organ-level delivery strategies for the management of certain disease conditions.

Effective endosomal escape after cellular uptake represents a major challenge in the field of nanodelivery, as the majority of drug payloads must localize to subcellular compartments other than the endosomes in order to exert activity. In nature, viruses can readily deliver their genetic material to the cytosol of host cells by triggering membrane fusion after endocytosis. For the influenza A virus, the hemagglutinin (HA) protein found on its surface fuses the viral envelope with the surrounding membrane at endosomal pH values. Biomimetic nanoparticles capable of endosomal escape were fabricated using a membrane coating derived from cells engineered to express HA on their surface. When evaluated in vitro, these virus-mimicking nanoparticles were able to deliver an mRNA payload to the cytosolic compartment of target cells, resulting in the successful expression of the encoded protein. When the mRNA-loaded nanoparticles were administered in vivo, protein expression levels were significantly increased in both local and systemic delivery scenarios. We therefore conclude that utilizing genetic engineering approaches to express viral fusion proteins on the surface of cell membrane-coated nanoparticles is a viable strategy for modulating the intracellular localization of encapsulated cargoes., (© 2021 Wiley-VCH GmbH.)

As numerous diseases are associated with increased local inflammation, directing drugs to the inflamed sites can be a powerful therapeutic strategy. One of the common characteristics of inflamed endothelial cells is the up-regulation of vascular cell adhesion molecule-1 (VCAM-1). Here, the specific affinity between very late antigen-4 (VLA-4) and VCAM-1 is exploited to produce a biomimetic nanoparticle formulation capable of targeting inflammation. The plasma membrane from cells genetically modified to constitutively express VLA-4 is coated onto polymeric nanoparticle cores, and the resulting cell membrane-coated nanoparticles exhibit enhanced affinity to target cells that overexpress VCAM-1 in vitro. A model anti-inflammatory drug, dexamethasone, is encapsulated into the nanoformulation, enabling improved delivery of the payload to inflamed lungs and significant therapeutic efficacy in vivo. Overall, this work leverages the unique advantages of biological membrane coatings to engineer additional targeting specificities using naturally occurring target-ligand interactions., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)

Immunostimulatory agents, including adjuvants, cytokines, and monoclonal antibodies, hold great potential for the treatment of cancer. However, their direct administration often results in suboptimal pharmacokinetics, vulnerability to biodegradation, and compromised targeting. More recently, encapsulation into biocompatible nanoparticulate carriers has become an emerging strategy for improving the delivery of these immunotherapeutic agents. Such approaches can address many of the challenges facing current treatment modalities by endowing additional protection and significantly elevating the bioavailability of the encapsulated payloads. To further improve the delivery efficiency and subsequent immune responses associated with current nanoscale approaches, biomimetic modifications and materials have been employed to create delivery platforms with enhanced functionalities. By leveraging nature-inspired design principles, these biomimetic nanodelivery vehicles have the potential to alter the current clinical landscape of cancer immunotherapy., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Cardiovascular disease (CVD), which encompasses a number of conditions that can affect the heart and blood vessels, presents a major challenge for modern-day healthcare. Nearly one in three people has some form of CVD, with many suffering from multiple or intertwined conditions that can ultimately lead to traumatic events such as a heart attack or stroke. While the knowledge obtained in the past century regarding the cardiovascular system has paved the way for the development of life-prolonging drugs and treatment modalities, CVD remains one of the leading causes of death in developed countries. More recently, researchers have explored the application of nanotechnology to improve upon current clinical paradigms for the management of CVD. Nanoscale delivery systems have many advantages, including the ability to target diseased sites, improve drug bioavailability, and carry various functional payloads. In this review, we cover the different ways in which nanoparticle technology can be applied towards CVD diagnostics and treatments. The development of novel biomimetic platforms with enhanced functionalities is discussed in detail.

Recent advances in electrosynthesis of nanomaterials expanded structural and compositional variations accessible by the electrochemical method; however, reliably synthesizable morphological variety fall shy of that available by conventional solvothermal synthesis. In this communication, electrochemical preparation of surfactant‐free hollow nanoparticles is demonstrated. By anodic conversion of core‐shell precursors with metastable cores, hollowed nickel nanoparticles with uniform dimensions were synthesized and characterized. Implementation of TEM grids as the working electrodes, identical location tracking of the morphological evolution of single particles to anodic stimulus has been demonstrated. The synthesized nanoparticles were employed as catalysts for the alkaline hydrogen evolution reaction and exhibited catalytic rates that compare favorably to the Pt/C benchmark. This marks the first pure electrochemical synthesis of hollow nanoparticles and shall contribute to the structural diversification of electrosynthesized nanomaterials. [ABSTRACT FROM AUTHOR]

Single entity analysis is an important research topic in electrochemistry. Thus far, collisions of nanomaterials and subsequent interaction between electrodes and particles have been studied. Single entity electrochemistry exhibited inherent heterogeneity distinct from that of ensembles. By showing various current responses, single entity electrochemistry allows us to investigate the adsorbed chemical species on the electrode surface (dielectrics, hard nanoparticles, soft nanoparticles), enabling analysis of electrode‐particle interaction at the nanoscale. Electrochemical analysis of soft nanoparticles enabled the detection of biological materials and was applied to the synthesis of nanoparticles to be used as electrocatalysts. It shows great promise as a synthetic method for various structures of nanoparticles by reducing metal ions volume confined emulsion nanodroplets. [ABSTRACT FROM AUTHOR]

Effective endosomal escape after cellular uptake represents a major challenge in the field of nanodelivery, as the majority of drug payloads must localize to subcellular compartments other than the endosomes in order to exert activity. In nature, viruses can readily deliver their genetic material to the cytosol of host cells by triggering membrane fusion after endocytosis. For the influenza A virus, the hemagglutinin (HA) protein found on its surface fuses the viral envelope with the surrounding membrane at endosomal pH values. Biomimetic nanoparticles capable of endosomal escape were fabricated using a membrane coating derived from cells engineered to express HA on their surface. When evaluated in vitro, these virus‐mimicking nanoparticles were able to deliver an mRNA payload to the cytosolic compartment of target cells, resulting in the successful expression of the encoded protein. When the mRNA‐loaded nanoparticles were administered in vivo, protein expression levels were significantly increased in both local and systemic delivery scenarios. We therefore conclude that utilizing genetic engineering approaches to express viral fusion proteins on the surface of cell membrane‐coated nanoparticles is a viable strategy for modulating the intracellular localization of encapsulated cargoes. [ABSTRACT FROM AUTHOR]

• A novel nanodroplet electrochemistry synthesis of multimetallic nanoparticles. • Surfactant-free synthesis with homogeneous distribution of component atoms. • Efficient oxygen reduction electrocatalysis on synthesized nanoparticles with improved durability. Conventional solvothermal synthesis of nanoparticles relies on the metal-ligand chemistry in the control of size and exposed facets. Because the surfaces of the nanoparticles are typically covered with surfactant molecules, these synthetic nanoparticles are often ineffective catalysts for chemical transformations. Moreover, recent applications of nanoparticles as electrocatalysts require costly processes, such as calcination or potential cycling, when converting the nanoparticles to electrodes. Here, we report a novel electrochemical route in direct synthesis of surfactant-free multimetallic nanoparticles. The synthesis occurs by electrolysis of an aqueous nanodroplet (approximately 50 attoliter in volume) containing metal precursor ions, and the stoichiometry inside the nanodroplet precisely translates to the synthesized nanoparticle. Multimetallic nanoparticles of binary, ternary, and quaternary combinations are prepared employing Cu, Ag, Pd, Pt, and Au as constituents. The synthesized nanoparticles are evaluated as electrocatalysts for alkaline oxygen reduction. Particularly, Cu 0.75 Pd 0.25 and Cu 0.375 Pd 0.25 Pt 0.375 nanoparticles demonstrate catalytic performance comparable to the benchmark catalyst Pt/C and boast far superior durability, while consuming at least 200 fold less metal atoms. [ABSTRACT FROM AUTHOR]