Exposure to microcrystallized cellulose affects the health of tadpoles and sheds light on the threat these materials pose to amphibians

The increasing use of cellulose-based materials (CBMs) has provided beneficial applications in different sectors. However, its release into environments may represent an ecological risk, therefore demanding that ecotoxicological studies be conducted to understand the risks (current and future) of CBM pollution. Thus, we evaluated the possible effects of microcrystalline cellulose (CMs) in Physalaemus cuvieri tadpoles. After seven days of exposure to CMs (at 58.29 and 100 mg/L), the animals were subjected to behavioral evaluation, and different biomarkers (biometric and biochemical) were evaluated. Although our data do not point to a neurotoxic effect of CMs (inferred by the absence of behavioral changes and changes in AChE and BChE activity), animals exposed to CMs showed differences in body condition. Furthermore, we noticed an increase in the frequency of erythrocyte nuclear abnormalities and DNA damage, which were correlated with the ingestion of CMs. We noticed that the antioxidant activity of tadpoles exposed to CMs (inferred by SOD, CAT, and DPPH radical scavenging activity) was insufficient to control the increase in ROS and MDA production. Furthermore, exposure to CMs induced a predominant Th2-specific immune response, marked by suppressed IFN-γ and increased IL-10 levels, with a consequent reduction in NO levels. Principal component analysis and IBRv-2 indicate, in general, a primarily more toxic response to animals exposed to the highest CM concentration. Therefore, our study evidence that CMs affect the health of P. cuvieri tadpoles and sheds light on the threat these materials pose to amphibians.

Microencapsulated stem cells reduce cartilage damage in a material dependent manner following minimally invasive intra-articular injection in an OA rat model

Osteoarthritis (OA) is a degenerative disease of the joints for which no curative treatment exists. Intra-articular injection of stem cells is explored as a regenerative approach, but rapid clearance of cells from the injection site limits the therapeutic outcome. Microencapsulation of mesenchymal stem cells (MSCs) can extend the retention time of MSCs, but the outcomes of the few studies currently performed are conflicting. We hypothesize that the composition of the micromaterial's shell plays a deciding factor in the treatment outcome of intra-articular MSC injection. To this end, we microencapsulate MSCs using droplet microfluidic generators in flow-focus mode using various polymers and polymer concentrations. We demonstrate that polymer composition and concentration potently alter the metabolic activity as well as the secretome of MSCs. Moreover, while microencapsulation consistently prolongs the retention time of MSC injected in rat joints, distinct biodistribution within the joint is demonstrated for the various microgel formulations. Furthermore, intra-articular injections of pristine and microencapsulated MSC in OA rat joints show a strong material-dependent effect on the reduction of cartilage degradation and matrix loss. Collectively, this study highlights that micromaterial composition and concentration are key deciding factors for the therapeutic outcome of intra-articular injections of microencapsulated stem cells to treat degenerative joint diseases.

Novel biocatalysts based on enzymes in complexes with nano- and micromaterials

In today's world, there is a wide array of materials engineered at the nano- and microscale, with numerous applications attributed to these innovations. This review aims to provide a concise overview of how nano- and micromaterials are utilized for enzyme immobilization. Enzymes act as eco-friendly biocatalysts extensively used in various industries and medicine. However, their widespread adoption faces challenges due to factors such as enzyme instability under different conditions, resulting in reduced effectiveness, high costs, and limited reusability. To address these issues, researchers have explored immobilization techniques using nano- and microscale materials as a potential solution. Such techniques offer the promise of enhancing enzyme stability against varying temperatures, solvents, pH levels, pollutants, and impurities. Consequently, enzyme immobilization remains a subject of great interest within both the scientific community and the industrial sector. As of now, the primary goal of enzyme immobilization is not solely limited to enabling reusability and stability. It has been demonstrated as a powerful tool to enhance various enzyme properties and improve biocatalyst performance and characteristics. The integration of nano- and microscale materials into biomedical devices is seamless, given the similarity in size to most biological systems. Common materials employed in developing these nanotechnology products include synthetic polymers, carbon-based nanomaterials, magnetic micro- and nanoparticles, metal and metal oxide nanoparticles, metal-organic frameworks, nano-sized mesoporous hydrogen-bonded organic frameworks, protein-based nano-delivery systems, lipid-based nano- and micromaterials, and polysaccharide-based nanoparticles.

Identification and quantification of microplastics in agricultural farmland soil and textile sludge in Bangladesh

Although microplastic (MP) pollution of aquatic ecosystems is a high-priority study topic, the issue of terrestrial environment and textile manufacturing waste has received little attention. Thus, this study was carried out to investigate the presence of MPs in agricultural land near textile industries and textile sludge samples in Bangladesh. Thirty-two soil samples from four agricultural farmland and five sludge samples were collected and analyzed. We show that the MPs content from agricultural farmland soil and textile sludge samples was 2.13 × 10⁴ ± 0.13 × 10⁴ MPs/kg and 2.92 × 10⁴ ± 0.14 × 10⁴ MPs/kg, respectively. MPs with a size between 1.0 and 1.5 mm were the least frequent in both soil and textile sludge samples. Fibers were more prevalent in textile sludge and fragments in soil samples. In addition, the percentage of transparent/white MPs was higher in the soil samples, and those classified as "multicolor" and "others" were more frequent in the sludge samples. Nine types of polymers were identified in the soil samples: PS, EVA, latex, HDPE, PVC, ABS, CA, LDPE, and PP. Except for LDPE, all these polymers were also found in the textile sludge samples, in addition to PU, nylon, and FEP, totaling eleven polymer types. On the other hand, we did not find evidence to support the association between MP contamination in soil samples and MPs identified in textile sludge samples. As demonstrated in the principal components analysis (PCA), the analyzed samples were separated by PC1, which suggests that the MPs reported in the soil come from sources that are not directly related to the textile industries. Thus, further research is needed to fully reveal MPs' fate and ecological risks in the soil environment and textile sludge, and necessary action is required to control MP pollution in terrestrial ecosystems.

Micro/nanotechnology-inspired rapid diagnosis of respiratory infectious diseases

Humans have suffered from a variety of infectious diseases since a long time ago, and now a new infectious disease called COVID-19 is prevalent worldwide. The ongoing COVID-19 pandemic has led to research of the effective methods of diagnosing respiratory infectious diseases, which are important to reduce infection rate and help the spread of diseases be controlled. The onset of COVID-19 has led to the further development of existing diagnostic methods such as polymerase chain reaction, reverse transcription polymerase chain reaction, and loop-mediated isothermal amplification. Furthermore, this has contributed to the further development of micro/nanotechnology-based diagnostic methods, which have advantages of high-throughput testing, effectiveness in terms of cost and space, and portability compared to conventional diagnosis methods. Micro/nanotechnology-based diagnostic methods can be largely classified into (1) nanomaterials-based, (2) micromaterials-based, and (3) micro/nanodevice-based. This review paper describes how micro/nanotechnologies have been exploited to diagnose respiratory infectious diseases in each section. The research and development of micro/nanotechnology-based diagnostics should be further explored and advanced as new infectious diseases continue to emerge. Only a handful of micro/nanotechnology-based diagnostic methods has been commercialized so far and there still are opportunities to explore.

SEM, XRD and FTIR analyses of both ultrasonic and heat generated activated carbon black microstructures

The microstructures of the activated carbon black microparticles (ACBMPs) generated through both treatments of 20 min ultrasonic and 400 °C thermal energy equivalent have been analyzed properly using scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier-transformed infrared (FTIR) spectroscopy methods. The research was aiming to generate binding or active sites points on the outer surface of the ACBMPs body of which commonly plays an important role in both adsorption and catalytic processes. It was observed that around 150 nm up to 400 nm in average diameter super macro voids with many various turns of nano-scale wells, and around 1.84 angstrom (Å) up to 15.98 Å intraparticle pores were generated. In addition, the parallel planes spacing of the carbonaceous framework sheets, namely d hkl in Miller indexes terminology, of about 4.44 Å up to 2.98 Å constructed the inner particles of the ACBMPs body. A new nomenclature method for the binding or active site shapes identification and classifying them into four categories based on the quadrants terminology, i.e. quadrant one (Q1), two (Q2), three (Q3) and four (Q4) is proposed. Each the quadrants contains four categories of turns types, i.e. sharp, semi sharp, obtuse and non-significant turns depending on the angle of the associated turn in radian angle, θ. Finally, it can be concluded that the combination of ultrasonic and thermal energy treatments in fabricating ACBMPs could generate binding or active site points with unique shapes as a transit terminal for any guest molecules, in this context is methyl red (MR) molecules to enter into the suitable intra-particles pores of the ACBMPs body.