Near-Infrared Activation of Sensory Rhodopsin II Mediated by NIR-to-Blue Upconversion Nanoparticles

Redefining Molecular Probes for Monitoring Subcellular Environment: A Perspective

The development of small-molecule fluorescent probes has revolutionized the monitoring of in vivo physicochemical parameters, offering unprecedented insights into biological processes. In this perspective, we critically examine recent advances and trends in the design and application of fluorescent probes for real-time in vivo monitoring of subcellular environments. Traditional concepts such as membrane potential, microviscosity, and micropolarity have been superseded by more biologically relevant parameters like membrane voltage, tension, and hydration, enhancing the accuracy of physiological assessments. This redefinition not only presents an evolved concept with broader applications in monitoring subcellular dynamics but also addresses the unmet needs of subcellular biology more effectively. We also highlight the limitations of commonly used probes in providing specific information about the redox environment, noting their nonspecificity to oxidants and the influence of various chemical interactions. These probes typically rely on free radical mechanisms and require metal catalysts to react with hydrogen peroxide. They include naphthalimide, fluorescein, BODIPY, rhodamine, cyanine cores to cover the UV-vis-near-infrared window. The motif of this perspective is to provide critical insights into trending fluorescent-based systems employed in real-time or in vivo physicochemical-responsive monitoring, thus aiming to inform and inspire further research in creating robust and efficient fluorescent probes for comprehensive in vivo monitoring applications.

Photodynamic Therapy for Atherosclerosis: Past, Present, and Future

This review paper examines the evolution of photodynamic therapy (PDT) as a novel, minimally invasive strategy for treating atherosclerosis, a leading global health concern. Atherosclerosis is characterized by the accumulation of lipids and inflammation within arterial walls, leading to significant morbidity and mortality through cardiovascular diseases such as myocardial infarction and stroke. Traditional therapeutic approaches have primarily focused on modulating risk factors such as hypertension and hyperlipidemia, with emerging evidence highlighting the pivotal role of inflammation. PDT, leveraging a photosensitizer, specific-wavelength light, and oxygen, offers targeted treatment by inducing cell death in diseased tissues while sparing healthy ones. This specificity, combined with advancements in nanoparticle technology for improved delivery, positions PDT as a promising alternative to traditional interventions. The review explores the mechanistic basis of PDT, its efficacy in preclinical studies, and the potential for enhancing plaque stability and reducing macrophage density within plaques. It also addresses the need for further research to optimize treatment parameters, mitigate adverse effects, and validate long-term outcomes. By detailing past developments, current progress, and future directions, this paper aims to highlight PDT's potential in revolutionizing atherosclerosis treatment, bridging the gap from experimental research to clinical application.

Rhodopsins: An Excitingly Versatile Protein Species for Research, Development and Creative Engineering

The first member and eponym of the rhodopsin family was identified in the 1930s as the visual pigment of the rod photoreceptor cell in the animal retina. It was found to be a membrane protein, owing its photosensitivity to the presence of a covalently bound chromophoric group. This group, derived from vitamin A, was appropriately dubbed retinal. In the 1970s a microbial counterpart of this species was discovered in an archaeon, being a membrane protein also harbouring retinal as a chromophore, and named bacteriorhodopsin. Since their discovery a photogenic panorama unfolded, where up to date new members and subspecies with a variety of light-driven functionality have been added to this family. The animal branch, meanwhile categorized as type-2 rhodopsins, turned out to form a large subclass in the superfamily of G protein-coupled receptors and are essential to multiple elements of light-dependent animal sensory physiology. The microbial branch, the type-1 rhodopsins, largely function as light-driven ion pumps or channels, but also contain sensory-active and enzyme-sustaining subspecies. In this review we will follow the development of this exciting membrane protein panorama in a representative number of highlights and will present a prospect of their extraordinary future potential.