Effective Carrier Research Articles

Investigation into the carrier recombination in Sb2Se3: Photo thermal effect, trapped carrier absorption and hot carrier cooling

Understanding the carrier recombination processes in Sb2Se3 is essential for its optoelectronic applications. In this work, carrier recombination dynamics in Sb2Se3 were studied by broad band transient absorption spectroscopy. Firstly, the contribution of photothermal effect to the transient absorption spectrum was thoroughly discussed. It is confirmed that the excited state absorption (ESA) band with lifetime of several nanoseconds results from co-contribution of photo thermal effect and deep trapped carrier absorption. Secondly, the features of transient absorption spectrum on picosecond time scale were interpreted. The short-lived ESA band around 1000 nm was assigned to shallow trapped carrier absorption, while not band gap renormalization (BGR) or free carrier absorption. By globally fitting the transient absorption spectrum, the hot carrier cooling time and time constant for free carrier relax into deep trap state were determined to be 0.25∼0.45 ps and 3.1∼8.7 ps, respectively. Finally, we built up the carrier recombination model of Sb2Se3. The experimental results in this work will improve the understanding on the carrier recombination in Sb2Se3.

A study on improving drug–drug interactions prediction using convolutional neural networks

Appropriate studies on drug–drug interactions (DDIs) can evade possible adverse side effects due to the ingestion of multiple drugs. This paper proposes a novel framework called Similarity Network Fusion and Hybrid Convolutional Neural Network (SNF–HCNN) to predict the DDIs better. The proposed framework leverages data from DrugBank, PubChem, and SIDER. Seven critical drug features are extracted: Target, Transporter, Enzymes, Chemical substructure, Carrier, Offside, and Side effects. The Jaccard Similarity measure evaluates the similarity of drug features to construct a comprehensive similarity matrix that effectively captures potential drug relationships and patterns. The similarity selection process identifies the most relevant features, reduces redundancy, and enhances identifying potential drug interactions. Integrating Similarity Network Fusion (SNF) with the selected similarity matrix ensures a comprehensive representation of drug features and leads to superior accuracy compared to conventional methods. Our experimental results demonstrate the effectiveness of the proposed hybrid convolutional neural network (HCNN) architectures, such as CNN+LR (CNN+Logistic Regression), CNN+RF (CNN+Random Forest), and CNN+SVM (CNN+Support Vector Machine), showing impressive accuracies of 95.19%, 94.45%, and 93.65%, respectively. Moreover, CNN+LR outperforms other approaches regarding precision, sensitivity, F1-score, and AUC score, which implicate better outcomes for ensuring medication safety aspects in clinical settings in the future.

Robotic grinding and polishing of complex aeroengine blades based on new device design and variable impedance control

Owing to the advantages of good flexibility and low cost, robots are gradually replacing manual labor as an effective carrier for the grinding and polishing of aeroengine blades. However, the geometric features of blades are complex and diverse, and the contour accuracy and surface quality requirements are high, making the robotic grinding and polishing of blades still a challenging task. For this reason, this article first designs a new device by integrating different tools, which can achieve full-feature grinding and polishing of blades. Then, in order to improve the accuracy and stability of force tracking during the robotic grinding and polishing processes, a variable impedance control approach with simultaneous changes in stiffness and damping and parameter boundaries is proposed. Finally, the superiority of the proposed variable impedance control method is verified by comparative experiments on surface tracking. In addition, by combining the device with the variable impedance control method in the robotic grinding and polishing experiments of an aeroengine blade, their effectiveness in practical situations is confirmed.

Shear‐Strained Pd Single‐Atom Electrocatalysts for Nitrate Reduction to Ammonia

AbstractElectrochemical nitrate reduction method (NitRR) is a low‐carbon, environmentally friendly, and efficient method for synthesizing ammonia, which has received widespread attention in recent years. Copper‐based catalysts have a leading edge in nitrate reduction due to their good adsorption of *NO3. However, the formation of active hydrogen (*H) on Cu surfaces is difficult and insufficient, resulting in a large amount of the by‐product NO2−. In this work, Pd single atoms suspended on the interlayer unsaturated bonds of CuO atoms formed due to dislocations (Pd−CuO) were prepared by low temperature treatment, and the Pd single atoms located on the dislocations were subjected to shear stress and the dynamic effect of support formation to promote the conversion of nitrate into ammonia. The catalysis had an ammonia yield of 4.2 mol. gcat−1. h−1, and a Faraday efficiency of 90 % for ammonia production at −0.5 V vs. RHE. Electrochemical in situ characterization and theoretical calculations indicate that the dynamic effects of Pd single atoms and carriers under shear stress obviously promote the production of active hydrogen, reduce the reaction energy barrier of the decision‐making step for nitrate conversion to ammonia, further promote ammonia generation.

Shear-Strained Pd Single-Atom Electrocatalysts for Nitrate Reduction to Ammonia.

Electrochemical nitrate reduction method (NitRR) is a low-carbon, environmentally friendly, and efficient method for synthesizing ammonia, which has received widespread attention in recent years. Copper-based catalysts have a leading edge in nitrate reduction due to their good adsorption of *NO3. However, the formation of active hydrogen (*H) on Cu surfaces is difficult and insufficient, resulting in a large amount of the by-product NO2 -. In this work, Pd single atoms suspended on the interlayer unsaturated bonds of CuO atoms formed due to dislocations (Pd-CuO) were prepared by low temperature treatment, and the Pd single atoms located on the dislocations were subjected to shear stress and the dynamic effect of support formation to promote the conversion of nitrate into ammonia. The catalysis had an ammonia yield of 4.2 mol. gcat -1. h-1, and a Faraday efficiency of 90 % for ammonia production at -0.5 V vs. RHE. Electrochemical in situ characterization and theoretical calculations indicate that the dynamic effects of Pd single atoms and carriers under shear stress obviously promote the production of active hydrogen, reduce the reaction energy barrier of the decision-making step for nitrate conversion to ammonia, further promote ammonia generation.

Precisely Regulating Asymmetric Charge Distribution by Single‐Atom Central Doped Ag‐Based Series Clusters for Enhanced Photoreduction of CO2 to Alcohol Fuels

AbstractHigh efficiently photocatalytic CO2 reduction (CO2RR) into liquid fuels in pure water system remains challenged. Iron polyphthalocyanine (FePPc) with strong light harvesting, unique Fe‐N4 structure, abundant pores, and good stability could serve as a promising catalyst for CO2 photoreduction. To further improve the catalytic efficiency, herein, symmetry‐breaking Fe sites are constructed by coupling with atomically precise M1Ag24 (M=Ag, Au, Pt) series clusters. Especially, the introduction of Pt1Ag24 causes the most asymmetric charge distribution of Fe in FePPc (followed by Au1Ag24 and Ag25), leading to the favorable CO2 adsorption and activation. In addition, Pt1Ag24‐FePPc exhibits the most effective photogenerated carriers transfer and separation. As a result, Pt1Ag24‐FePPc shows the methanol/ethanol yield of 48.55/32.97 μmol ⋅ gcat−1 ⋅ h−1 in H2O‐CO2 system under visible light irradiation, ~1.65/1.25‐fold, 1.83/1.37‐fold, and 3.60/1.61‐fold higher than that of Au1Ag24‐FePPc, Ag25‐FePPc, and FePPc, respectively. This work provides a concept for precisely construction and regulation symmetry‐breaking sites of cluster‐based catalysts for effective CO2 conversion.

Study on synergistic effect of carrier combined with micro-aeration on anaerobic digestion of food waste

Enhancing the conversion efficiency of methane production from food waste (FW) is always a hot issue. Biological carriers and micro-aeration had demonstrated notable advantages in enhancing anaerobic digestion (AD) efficiency, but their synergistic potential remained largely untapped. This study introduced polyurethane carriers into micro-aeration assisted AD, trying to explore their synergism in enhancing the digestive efficiency of FW. Results revealed that an optimal blend of carriers and micro-aeration pose significant improvement to the digestive performance. Their combination enhanced microbial metabolic activity, accelerated the consumption or conversion of dissolved organic matter (DOM) molecules, promoted the aggregation of microorganisms, which improved their tolerance capacity under the oxygen stress brought by the micro-aeration, ensuring the system stability. It also enriched methane-producing microorganisms, and balanced methane-producing pathways. Additionally, the combination of micro-aeration and carriers promoted key enzyme expression in metabolic pathways, providing ample support for methane production. These findings held significance for optimizing FW treatment, improving methane production efficiency, and reducing the burden of organic waste treatment.

A novel nanoscale FD-SOI MOSFET with energy barrier and heat-sink engineering for enhanced electric field uniformity

This paper aims to present a novel method to mitigate the undesirable issues associated with short-channel-effects (SCEs) and the critical lattice temperature of a fully depleted silicon-on-insulator (FD-SOI) MOSFET in the nanoscale regime. The proposed approach is based on simultaneously merging the energy barrier and heat-sink engineering simultaneously. Hafnium oxide as a high-k dielectric inside the channel region around the drain region is embedded to redistribute the band energy resulting in the enhancement of the energy barrier. This reformation of the band profile reduces variations in the channel depletion charge volume percentage caused by the drain voltage, thereby mitigating short-channel effects (SCEs). In order to promote effective thermal conduction, a portion of the buried oxide is replaced by doped P-type silicon which acts as an effective heat-sink. The devices under the investigation have been simulated using SILVACO software, considering the comprehensive physical models. Drain-Induced Barrier Lowering (DIBL), leakage current, Ion to Ioff ratio, subthreshold swing, hot carrier effect and lattice temperature as the essential parameters have been successfully improved for the proposed device in comparison to the conventional device.

Enhanced phosphorus removal from anoxic water using oxygen-carrying iron-rich biochar: Combined roles of adsorption and keystone taxa

Anthropogenic enrichment of phosphorus (P) in water environment can cause eutrophication, harmful algal blooms, and water quality deterioration. Adsorbents are often used for the removal and recovery of P from water, however, P is highly susceptible to re-release in anoxic benthic environments. As a response, this study prepared oxygen-carrying iron-rich biochar (O-Fe-BC) as an effective oxygen micro-nanobubble carrier (Q = 8.7024 cm³/g STP at 1.5 MPa) and P adsorbent (qm = 16.7097 mg P/g, q0.1 = 3.1974 mg P/g). Over the 90-day experimental period with O-Fe-BC, dissolved oxygen (DO) levels in the overlying water could maintain at ∼4 mg/L (peaking at ∼9.5 mg/L), and total phosphorus (TP) and soluble reactive phosphorus (SRP) levels decreased by over 96 %. The higher inorganic phosphorus content in the surface sediment-biochar mixture, along with the lower labile P and Fe concentration in the sediment pore water in the O-Fe-BC group compared to other groups, suggested the enhanced P immobilization. Further mechanism exploration revealed the combined roles of adsorption and microbial response, in which O-Fe-BC achieved efficient phosphate adsorption primarily through inner-sphere complexation via ligand exchange and keystone taxa (particularly Candidatus Electronema) played a crucial role in driving water chemistry divergence. Specially, these cable bacteria could provide large pools of Fe oxides in the surface sediment, binding with P to prevent its release, as supported by significant correlations between Ca. Electronema abundance and oxidation–reduction potential (ORP), TP, SRP, and sediment Fe-P variations. Additionally, a pot experiment with mung bean seedlings showed that the recovered O-Fe-BC significantly promoted the seed germination and growth, indicating its potential as a novel material for removing and recovering P from eutrophic waters. Taken together, our work provided a promising strategy for sustainable anoxia and P pollution mitigation, and also highlighted the indispensable roles of inner-sphere adsorption in P recovery and microbial keystone taxa in P cycling regulation.

Sensitization of AgInS2 nanoparticles enhances photoelectrochemical water splitting performance of CeO2 nanosheet arrays photoanode

In this study, we present a promising CeO2/AgInS2 heterostructure photoanode for photoelectrochemical (PEC) water decomposition. Mott-Schottky analysis is employed to confirm the formation of a type-II heterostructure between AgInS2 nanoparticles and CeO2 nanosheet arrays (NSAs) fabricated through electrochemical deposition and successive ionic layer adsorption and reaction. Electrochemical impedance spectroscopy, photoluminescence analysis, and Bode diagram spectroscopy confirm the effective charge carrier separation and significantly prolonged the charge lifetime of the CeO2/AgInS2 heterojunction photoanode. Consequently, the maximum photocurrent density of the constructed CeO2/AgInS2 photoanode relative to Ag/AgCl under zero bias test conditions is 69.8 times higher than the pure CeO2 NSAs. Additionally, the charge transfer mechanism is further verified by the calculated work function and differential charge density of CeO2/AgInS2 heterojunction. This study provides a valuable reference for the synthesis and preparation of heterojunction photoanode for efficient PEC water decomposition.

A Detailed First‐Principles Study of the Structural, Elastic, Thermomechanical, and Optoelectronic Properties of Binary Rare‐Earth Tritelluride NdTe3

AbstractRare‐earth tritellurides (RTe3) are popular for their charge density wave (CDW) phase, magnetotransport properties, and pressure‐induced superconducting state among other features. In this literature, Density functional theory is exploited to study various properties of NdTe3. The calculated elastic and thermomechanical parameters, which are hitherto untouched for any RTe3, uncover soft, ductile, highly machinable, and damage‐tolerant characteristics, as well as highly anisotropic mechanical behavior of this layered compound. Its thermomechanical properties make it a prospective thermal barrier coating material. Band structure, density of states, Fermi surfaces, and various optical functions of the material are reported. The band structure demonstrates highly directional metallic nature. The highly dispersive bands indicate very low effective charge carrier mass for the in‐plane directions. The Fermi surfaces display symmetric pockets, including signs of nesting, bilayer splitting among others, corroborating previous works. The optical spectra expose high reflectivity across the visible region, while absorption is high in the ultraviolet region. Two plasma frequencies are noticed in the optical loss function. The optical conductivity, reflectivity, and absorption reaffirm its metallic properties. The electronic band structure manifests evidence of CDW phase in the ground state.

Constructing interfacial electric field with rich oxygen vacancy modulated heterojunction FeVO4-MgZnAl LDH for enhanced photocatalytic degradation of doxycycline

FeVO4 nanorods were synthesized and integrated with plate-like MgZnAl layered double hydroxide (MZA LDH) using a combination of sonochemical coprecipitation and hydrothermal methods. The resulting FeVO4-MgZnAl LDH nanocomposites (NCs) were engineered to enhance photocatalytic performance through an S-scheme charge transfer mechanism. These NCs exhibited exceptional photocatalytic activity, achieving 93.7 % degradation of doxycycline (DXY) which is significantly outperforming its counterparts, FeVO4 (29.8 %) and MgZnAl LDH (49.8 %). Detailed analysis using scavenging tests and electron spin resonance (ESR) analysis confirmed that the photoexcited charges follow the S-scheme pathway, leading to the generation of hydroxyl (•OH) and superoxide (O2•⁻) radicals. This mechanism remarkedly improves the catalytic efficiency of FeVO4-MZA NCs with a kinetic rate constant of 4–9 times higher than those of its individual components. The photocatalyst's were comprehensively characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–visible diffuse reflectance spectroscopy (UV–vis-DRS), photoluminescence (PL) spectroscopy, and electrochemical impedance spectroscopy (EIS). The FeVO₄-MZA NCs demonstrated remarkable stability and reusability, indicating their suitability for large-scale water treatment applications. Additionally, the non-toxic nature of FeVO4-MZA NCs, coupled with effective charge carrier separation and reduced recombination rates, establishes them as highly efficient photocatalysts for the removal of pharmaceutical contaminants from aquatic systems and paves a way for manufacturing innovation.

Cellulose acetate fibers as corrosion inhibitor delivery system for carbon steel

This study evaluated the effectiveness of electrospun cellulose acetate fibers (CAFs) containing oleic acid (OA) for corrosion inhibition on carbon steel in chloride-rich environments. By varying the OA content, CAFs of different thicknesses were produced. Potentiodynamic polarization showed that steel coated with OA-containing CAFs had enhanced corrosion resistance, with higher corrosion potential (Ecorr) and lower corrosion current density (icorr). The electrochemical impedance spectroscopy (EIS) results for the dip-coated sample showed an impedance increase of approximately 20× (from 2 to 40 kΩ cm2), and a capacitance reduction from 10−6 to 10−8 F cm−2, compared to the untreated sample. The protective effect remained even after 48 h of exposure. These findings suggest CAFs as effective carriers for delivering OA inhibitors, offering a promising solution for corrosion mitigation in saline environments.

Micelles of poly[oligo(ethylene glycol) methacrylate] as delivery vehicles for zinc phthalocyanine photosensitizers

Drug-loaded polymeric micelles have proven to be highly effective carrier systems for the efficient delivery of hydrophobic photosensitizers (PSs) in photodynamic therapy (PDT). This study introduces the micellization potential of poly(oligoethylene glycol methyl ether methacrylate) (pOEGMA) as a novel approach, utilizing the hydrophobic methacrylate segments of pOEGMA to interact with highly hydrophobic zinc phthalocyanine (ZnPc), thereby forming a potential micellar drug carrier system. The ZnPc molecule was synthesized from phthalonitrile derivatives and its fluorescence, photodegradation, and singlet oxygen quantum yields were determined in various solvents. In solvents such as tetrahydrofuran, dimethyl sulfoxide, and N,N-dimethylformamide, the ZnPc compound exhibited the requisite photophysical and photochemical properties for PDT applications. The pOEGMA homopolymer was synthesized via reversible addition-fragmentation chain-transfer polymerization, while ZnPc-loaded pOEGMA micelles were prepared using the nanoprecipitation method. Characterization of the pOEGMA, ZnPc, and micelles was conducted using FTIR,1H-NMR, dynamic light scattering, matrix-assisted laser desorption/ionization time-of-flight mass spectrometries, gel permeation chromatography, and transmission electron microscopy. The critical micelle concentration was determined to be 0.027 mg ml-1using fluorescence spectrometry. The drug loading and encapsulation efficiencies of the ZnPc-loaded micelles were calculated to be 0.67% and 0.47%, respectively. Additionally, the release performance of ZnPc from pOEGMA micelles was monitored over a period of nearly 10 d, while the lyophilized micelles exhibited stability for 3 months. Lastly, the ZnPc-loaded micelles were more biocompatible than ZnPc on L929 cell line. The results suggest that the pOEGMA homopolymer possesses the capability to micellize through its methacrylate segments when interacting with highly hydrophobic molecules, presenting a promising avenue for enhancing the delivery efficiency of hydrophobic PSs in PDT. Moreover, it was also deciphered that obtained formulations were highly biocompatible according to cytotoxicity results and could be safely employed as drug delivery systems in further applications.

Investigating the In Vivo Biodistribution of Extracellular Vesicles Isolated from Various Human Cell Sources Using Positron Emission Tomography.

Positron emission tomography (PET) is a powerful tool for investigating the in vivo behavior of drug delivery systems. We aimed to assess the biodistribution of extracellular vesicles (EVs), nanosized vesicles secreted by cells isolated from various human cell sources using PET. EVs were isolated from mesenchymal stromal cells (MSCs) (MSC EVs), human macrophages (Mϕ EVs), and a melanoma cell line (A375 EVs) by centrifugation and were conjugated with deferoxamine for radiolabeling with Zr-89. PET using conjugated and radiolabeled EVs evaluated their in vivo biodistribution and tissue tropisms. Our study also investigated differences in mouse models, utilizing immunocompetent and immunocompromised mice and an A375 xenograft tumor model. Lastly, we investigated the impact of different labeling techniques on the observed EV biodistribution, including covalent surface modification and membrane incorporation. PET showed that all tested EVs exhibited extended in vivo circulation and generally low uptake in the liver, spleen, and lungs. However, Mϕ EVs showed high liver uptake, potentially attributable to the intrinsic tissue tropism of these EVs from the surface protein composition. MSC EV biodistribution differed between immunocompetent and immunodeficient mice, with increased spleen uptake observed in the latter. PET using A375 xenografts demonstrated efficient tumor uptake of EVs, but no preferential tissue-specific tropism of A375 EVs was found. Biodistribution differences between labeling techniques showed that surface-conjugated EVs had preferential blood circulation and low liver, spleen, and lung uptake compared to membrane integration. This study demonstrates the potential of EVs as effective drug carriers for various diseases, highlights the importance of selecting appropriate cell sources for EV-based drug delivery, and suggests that EV tropism can be harnessed to optimize therapeutic efficacy. Our findings indicate that the cellular source of EVs, labeling technique, and animal model can influence the observed biodistribution.

High-yield extracellular vesicle production from HEK293T cells encapsulated in 3D auxetic scaffolds with cyclic mechanical stimulation for effective drug carrier systems

Extracellular vesicles (EVs) show promise in drug loading and delivery for medical applications. However, the lack of scalable manufacturing processes hinders the generation of clinically suitable quantities, thereby impeding the translation of EV-based therapies. Current EV production relies heavily on non-physiological two-dimensional (2D) cell culture or bioreactors, requiring significant resources. Additionally, EV-derived ribonucleic acid cargo in three-dimensional (3D) and 2D culture environments remains largely unknown. In this study, we optimized the biofabrication of 3D auxetic scaffolds encapsulated with human embryonic kidney 293 T (HEK293 T) cells, focusing on enhancing the mechanical properties of the scaffolds to significantly boost EV production through tensile stimulation in bioreactors. The proposed platform increased EV yields approximately 115-fold compared to conventional 2D culture, possessing properties that inhibit tumor progression. Further mechanistic examinations revealed that this effect was mediated by the mechanosensitivity of YAP/TAZ. EVs derived from tensile-stimulated HEK293 T cells on 3D auxetic scaffolds demonstrated superior capability for loading doxorubicin compared to their 2D counterparts for cancer therapy. Our results underscore the potential of this strategy for scaling up EV production and optimizing functional performance for clinical translation.

Ingenious development of bandgap engineered MIL-101(Fe) core-shell supported on SnO2/ZnO heterojunction and its photocatalytic activity towards azo dye degradation: Process optimization and mechanistic insight

Water pollution is a pressing global concern, exacerbated by industrial effluents containing hazardous azo-dyes such as Trypan blue (TB) and Methyl orange (MO), which contaminate water bodies and threaten ecosystems. The scarcity of pure water intensifies the urgency to develop effective remediation strategies to tackle the toxic dye pollutants. In the present work, an attempt has been made to fabricate and utilize a novel ternary MOF-based SnO2/ZnO@MIL-101(Fe) photocatalyst for the removal of TB and MO dyes from an aqueous medium. The photocatalyst was characterized using various analytical techniques, like XRD, FTIR, UV–vis DRS, PL, SEM, TEM, and XPS, which provide insights into the composites’ crystal structure, morphology, and optical properties, which are crucial for understanding their photocatalytic behavior. The photocatalytic performance of the heterojunction was investigated under various reaction parameters such as catalyst dosage, initial concentration of dyes, and light irradiation time. The results demonstrated the superior performance of the SnO2/ZnO@MIL-101(Fe) composites in degrading the mono-azo and di-azo dyes under visible light irradiation via a photo-fenton process. The maximum degradation efficiency of 97.44 % and 98.8 % were obtained for TB and MO within 30 and 55 min, respectively. Furthermore, the change in the total organic carbon (TOC) was monitored to verify the degree of mineralization of the azo dyes. The extremely high dye degradation activity and TOC removal can be attributed to the formation of a suitable heterojunction interface between the components of the photocatalyst, leading to effective charge carrier transport and the generation of active radicals. Finally, based on the radical scavenging experiments, ESR, and VB-XPS analysis, a plausible mechanism for the photodegradation process was derived. This research contributes to the advancement of sustainable water treatment technologies by providing insights into the design, fabrication, and utilization of novel composites for efficient remediation of dye-contaminated wastewater.

A Review on Nanosponges: An Idiosyncratic Approach for Delivery of Proactive Molecules

Background: A lot of work has been done by many researchers to develop a system that is targeted at a specific site. Nanosponges are one of the systems that serve this purpose and have several advantages over other methods. Objective: The article’s strategy is to provide access to data regarding the nanosponges system, including its preparation, evaluation, and advantages in various fields, such as the transportation of proteins, vaccines, biocatalysts, and drugs with enhanced bioavailability. Nanosponges also contribute significantly to the treatment of breast cancer, lung cancer, fungal infection, water treatment, and topical application than other approaches. Method: Nanosponges contain a solid, porous system in which hydrophilic or lipophilic drugs are loaded at their core in the nanocavity. All the information provided in this article was collected after analysing various reports on nanosponges available on Google Scholar, PubMed, Scopus, Web of Science, and Science Direct. It is concluded that the nanosponges have excellent aqueous solubility properties. Therefore, they can be used as carriers for drugs with poor water solubility. Moreover, greater bioavailability can be achieved by using the nanosponge approach. Conclusion: Nanosponges possess various outstanding properties that form the unique system of this approach. Nanosponges provide an effective carrier system for enzymes, proteins, vaccines, and therapeutic fields. This review provides a broad overview of the development of nanosponges, their evaluation, and the uses of nanosponges based on cyclodextrin for drug delivery.

In silico Design of a Quadruplex RNA Aptamer Against Carcinoembryonic Antigen, and Evaluating its Potential as a Drug Delivery Vehicle

Background: Colorectal cancer is the third most common cancer worldwide, with carcinoembryonic antigen (CEA) being a key biomarker for tumor prognostic assessment. This study focused on the in silico development of an RNA aptamer capable of efficiently targeting the CEA biomarker, and evaluating its potential to act as a drug delivery vehicle of chemotherapeutic anticancer drugs. Methods: In this study, five G-quadruplex RNA aptamers were manually designed and docked with the CEA protein. The aptamer sequence with the best docking score was optimized through various mutations, and these mutant sequences underwent drug-aptamer docking using AutoDock vina, followed by further docking experiments with CEA, with and without the drug, using the Hdock server. The best aptamer-drug configuration and the entire (aptamers-drug)-CEA complex were then analyzed using molecular dynamics (MD) simulation. Results: Irinotecan exhibited the highest binding affinity with three mutant sequences compared to 5-FU and Raltitrexed, with the seq 3-5/Irinotecan complex showing the best configuration (score: -11.6). This complex also demonstrated a good binding affinity with the target CEA (HDOCK score: -393.07). Throughout 31.6 ns simulation, the RMSD plot of the (aptamer-drug)-CEA complex showed an average of 8.7 A°. The residues of interacting amino acids had lower RMSF than 1.4 Å, except for the ALA A0 (RMSF:1.74 Å). Rg plot showed minimal fluctuation, which were maintained between 19.2 Å and 20.2 Å. The mean SASA was in the range of 112.8–125.8 nm2. H-bonds were observed with an average of 7.3 hydrogen bonds. MD simulation results indicated that the (aptamers-drug)-CEA complex maintained a stable, low-flexibility, and relatively compact structure throughout the simulation. Conclusion: The study concludes that the designed quadruplex RNA aptamer can potentially target the CEA biomarker with good binding affinity and serves as an effective carrier for Irinotecan. However, in vitro and in vivo experiments are necessary for further validation.

Skin Delivery and Innovative Carrier’s Effectiveness

The skin serves as the body first protecting barrier against the external attacks of chemicals and microorganisms. On the other hand, it is an obstacle to penetration and transdermal delivery of any substance applied on its surface. Thus, a need to report some news on the skin composition for a better understanding of the transdermal delivery mechanisms of topical products applied on its surface. Therefore, due to the actual increased use of topical drugs, cosmetics, and diet supplement treatments, further feasibility research studies have been carried out to extend the knowledge of the percutaneous absorption ‘rules and means. These studies are retained necessary to control the release through the skin layers of various selected active ingredients, loaded and carried out by different vehicles. The paper will focus on the effectiveness of innovative tissue carriers that, are able to deliver active ingredients throughout the skin layers, are made by a very low consumption of water, and are free of chemicals also. In conclusion, these novel eco-sustainable carriers, resulting skin- and environmentally friendly, might be used as innovative vehicles in substitution of the normal emulsions that, made by the use of preservatives, emulsifiers, fragrances, and other chemicals may often cause allergic and/or sensitization phenomena, consuming a great quantity of water also.