Background Many eukaryote cells produce membrane-enclosed extracellular vesicles (EVs) to establish cell-to-cell communication. Plant-derived EVs (P-EVs) contain proteins, RNAs, lipids, and other metabolites that can be isolated from the juice, the flesh, and roots of many species. Methods In the present review study, we studied numerous articles over the past two decades published on the role of P-EVs in plant physiology as well as on the application of these vesicles in different diseases. Results Different types of EVs have been identified in plants that have multiple functions including reorganization of cell structure, development, facilitating crosstalk between plants and fungi, plant immunity, defense against pathogens. Purified from several edible species, these EVs are more biocompatible, biodegradable, and extremely available from many plants, making them useful for cell-free therapy. Emerging evidence of clinical and preclinical studies suggest that P-EVs have numerous benefits over conventional synthetic carriers, opening novel frontiers for the novel drug-delivery system. Exciting new opportunities, including designing drug-loaded P-EVs to improve the drug-delivery systems, are already being examined, however clinical translation of P-EVs-based therapies faces challenges. Conclusion P-EVs hold great promise for clinical application in the treatment of different diseases. In addition, despite enthusiastic results, further scrutiny should focus on unravelling the detailed mechanism behind P-EVs biogenesis and trafficking as well as their therapeutic applications.

The COVID-19 pandemic is currently an unprecedented public health threat. The rapid spread of infections has led to calls for alternative approaches to combat the virus. Nanotechnology is taking root against SARS-CoV-2 through prevention, diagnostics and treatment of infections. In light of the escalating demand for managing the pandemic, a comprehensive review that highlights the role of nanomaterials in the response to the pandemic is highly desirable. This review article comprehensively discusses the use of nanotechnology for COVID-19 based on three main categories: prevention, diagnostics and treatment. We first highlight the use of various nanomaterials including metal nanoparticles, carbon-based nanoparticles and magnetic nanoparticles for COVID-19. We critically review the benefits of nanomaterials along with their applications in personal protective equipment, vaccine development, diagnostic device fabrication and therapeutic approaches. The remaining key challenges and future directions of nanomaterials for COVID-19 are briefly discussed. This review is very informative and helpful in providing guidance for developing nanomaterial-based products to fight against COVID-19.

This study presents a sawtooth-like pulse anodization approach aiming to create a new type of photonic crystal structure based on nanoporous anodic alumina. This nanofabrication approach enables the engineering of the effective medium of nanoporous anodic alumina in a sawtooth-like manner with precision. The manipulation of various anodization parameters such as anodization period, anodization amplitude, number of anodization pulses, ramp ratio and pore widening time allows a precise control and fine-tuning of the optical properties (i.e., characteristic transmission peaks and interferometric colors) exhibited by nanoporous anodic alumina photonic crystals (NAA-PCs). The effect of these anodization parameters on the photonic properties of NAA-PCs is systematically evaluated for the establishment of a fabrication methodology toward NAA-PCs with tunable optical properties. The effective medium of the resulting NAA-PCs is demonstrated to be optimal for the development of optical sensing platforms in combination with reflectometric interference spectroscopy (RIfS). This application is demonstrated by monitoring in real-time the formation of monolayers of thiol molecules (11-mercaptoundecanoic acid) on the surface of gold-coated NAA-PCs. The obtained results reveal that the adsorption mechanism between thiol molecules and gold-coated NAA-PCs follows a Langmuir isotherm model, indicating a monolayer sorption mechanism.

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Herein, we present an interferometric sensor based on the combination of chemically functionalized nanoporous anodic alumina photonic films (NAA-PFs) and reflectometric interference spectroscopy (RIfS) aimed to detect trace levels of enzymes by selective digestion of gelatin. The fabrication and sensing performance of the proposed sensor were characterized in real-time by estimating the changes in effective optical thickness (i.e., sensing principle) of gelatin-modified NAA-PFs (i.e., sensing element) during enzymatic digestion. The working range (WR), sensitivity (S), low limit of detection (LLoD), and linearity (R(2)) of this enzymatic sensor were established by a series of experiments with different concentrations of gelatin (i.e., specific chemical sensing element) and trypsin (i.e., analyte), a model protease enzyme with relevant implications as a biomarker in the diagnosis of several diseases. The chemical selectivity of the sensor was demonstrated by comparison of gelatin digestion by other nonspecific enzyme models such as chymotrypsin and horseradish peroxidase. Furthermore, the role of the chemical sensing element (i.e., gelatin) was assessed by using hemoglobin instead of gelatin. Finally, we demonstrated that this sensor can be readily used to establish the kinetic parameters of enzymatic reactions. The obtained results revealed that the presented sensor has a promising potential to be used as a point-of-care system for fast detection of gastrointestinal diseases at early stages.