Establishing the Callus-Based Isolation of Extracellular Vesicles from Cissus quadrangularis and Elucidating Their Role in Osteogenic Differentiation

Extracellular vesicles (EVs) are nano-sized vehicles secreted by all live cells to establish communication with adjacent cells. In recent years, mammalian EVs (MEVs) have been widely investigated for their therapeutic implications in human disease conditions. As the understanding of MEV composition and nature is advancing, scientists are constantly exploring alternatives for EV production with similar therapeutic potential. Plant-derived exosome-like nanovesicles (PDEVs) may be a better substitute for MEVs because of their widespread sources, cost-effectiveness, and ease of access. Cissus quadrangularis (CQ), known as "bone setter or Hadjod", is a perennial plant utilized for its osteogenic potential. Its crude powder extract formulations are widely used as tablets and syrups. The present work elucidates the isolation of exosome-like nanovesicles (henceforth exosomes) from the culture supernatants of an in vitro cultured callus tissue derived from CQ. The physical and biological properties of the exosomes were successfully investigated using different characterization techniques. The therapeutic potential of the CQ exosomes was found to ameliorate the wound scratch injury and oxidative stress conditions in human-derived mesenchymal stem cells (hMSCs) and the pre-osteoblast (MC3T3) cell line. These exosomes also induced the proliferation and differentiation of hMSCs, as observed by alkaline phosphatase activity. These findings may serve as a proof of concept for further investigating the CQ exosomes as a nanocarrier for drug molecules in various therapeutic bone applications.

Modeling the COVID-19 Travel Choices in Colombia and India: A Hybrid Multiple Discrete-Continuous Nested Extreme Value Approach

The COVID-19 pandemic has affected many daily activities, primarily as a result of the perceived contagion risk and government restrictions to mitigate the spread of the virus. To this end, drastic changes in the trip choices for commuting to work have been reported and studied, mostly through descriptive analysis. On the other hand, modeling-based research that can simultaneously understand both changes in mode choice and its frequency at an individual level has not been much used in existing studies. As such, this study aims to understand the changes in mode-choice preference and the frequency of trips, comparing pre-COVID with during-COVID scenarios, in two different countries of the Global South: Colombia and India. A hybrid multiple discrete-continuous nested extreme value model was implemented using the data obtained from online surveys in Colombia and India during the early COVID-19 period of March and April 2020. This study found that, in both countries, utility related to active modes (more used) and public transportation (less used) changed during the pandemic. In addition, this study highlights potential risks in likely unsustainable futures where there may be increased use of private vehicles such as cars and motorcycles, in both countries. It was also identified that perceptions toward government responses had a significant impact on the choices in Colombia, though this was not the case in India. These results may help decision makers focus on public policies to encourage sustainable transportation by avoiding the detrimental long-term behavioral changes resulting from the COVID-19 pandemic.

SARS-CoV-2 and its new variants: a comprehensive review on nanotechnological application insights into potential approaches

SARS-CoV-2 (COVID-19) spreads and develops quickly worldwide as a new global crisis which has left deep socio-economic damage and massive human mortality. This virus accounts for the ongoing outbreak and forces an urgent need to improve antiviral therapeutics and targeted diagnosing tools. Researchers have been working to find a new drug to combat the virus since the outbreak started in late 2019, but there are currently no successful drugs to control the SARS-CoV-2, which makes the situation riskier. Very recently, new variant of SARS-CoV-2 is identified in many countries which make the situation very critical. No successful treatment has yet been shown although enormous international commitment to combat this pandemic and the start of different clinical trials. Nanomedicine has outstanding potential to solve several specific health issues, like viruses, which are regarded a significant medical issue. In this review, we presented an up-to-date drug design strategy against SARS-CoV-2, including the development of novel drugs and repurposed product potentials were useful, and successful drugs discovery is a constant requirement. The use of nanomaterials in treatment against SARS-CoV-2 and their use as carriers for the transport of the most frequently used antiviral therapeutics are discussed systematically here. We also addressed the possibilities of practical applications of nanoparticles to give the status of COVID-19 antiviral systems.

Progress on In Situ and Operando X-ray Imaging of Solidification Processes

In this review, we present an overview of significant developments in the field of in situ and operando (ISO) X-ray imaging of solidification processes. The objective of this review is to emphasize the key challenges in developing and performing in situ X-ray imaging of solidification processes, as well as to highlight important contributions that have significantly advanced the understanding of various mechanisms pertaining to microstructural evolution, defects, and semi-solid deformation of metallic alloy systems. Likewise, some of the process modifications such as electromagnetic and ultra-sound melt treatments have also been described. Finally, a discussion on the recent breakthroughs in the emerging technology of additive manufacturing, and the challenges thereof, are presented.