Medical Applications Research Articles

Steering Piezocatalytic Therapy for Optimized Tumoricidal Effect

AbstractPiezocatalysts, because of their mechano‐electrical conversion properties, are exploited for various medical applications, such as sterilization, tissue engineering, biosensing, and disease theranostics. In particular, based on the unique advantage of the piezoelectric effect, piezocatalytic therapy (PCT) has been developed as a novel and promising candidate for tumor therapy. To optimize the utilization of piezocatalysts in tumor therapy, a comprehensive understanding of the antitumor mechanism associated with these materials is imperative. Here, the piezocatalytic action principle is elucidated by investigating piezocatalysts, reactants, energy inputs, and products. Subsequently, the antitumor mechanisms of PCT have been extensively discussed and are recapitulative as follows: restraining cell proliferation, inducing cell programmed death, hindering tumor metastasis, inhibiting tumor angiogenesis, and enhancing antitumor immunity. Additionally, the optimized therapeutic outcomes of PCT‐centric synergistic cancer therapy are systematically described. Finally, the main challenges and future research directions of piezocatalysis applied in cancer therapy are envisioned. It is believed that PCT will serve as a new‐generation ingenious tool for cancer treatment.

Greening up the fight against emerging contaminants: algae-based nanoparticles for water remediation

AbstractNanoparticles are commonly used for different purposes, including as photocatalysts, biosensors, antibacterial, antifungal, and anticancer agents. Recently, the synthesis of nanoparticles via biological techniques has become popular due to cost efficiency, sustainability, and the least secondary pollutants generation. Plants, algae, and microorganisms are primarily used to synthesize bio-nanoparticles. Algae-based nanoparticles have gained more attention due to their catalytic activity against emerging organic contaminants such as dyes, phenols, and organosulfur compounds. Nevertheless, a systemic evaluation of the potential of algae-based nanoparticles in environmental remediation is yet to be conducted. This paper reviews recent progress in the biosynthesis of algae-based nanoparticles and the potential use of algae-based nanoparticles in environmental remediation. Furthermore, the review examines the factors that affect the properties and behaviors of algae-based nanoparticles. Additionally, the review briefly discusses other medical and industrial applications as well as advantages over physically and chemically synthesized nanoparticles. Challenges associated with the production process and usage of algae-based nanoparticles are also discussed, including the difficulty of predicting the properties of nanoparticles and adapting to large-scale processes. Overall, algae-based nanoparticles have several advantages, including their high stability and surface activity due to the presence of surface functional groups from algae species used for the synthesis of algae-based nanoparticles. However, further research is required to address the knowledge gaps and potential key research areas. Graphical Abstract

Silver-loaded poly(vinyl alcohol)/polycaprolactone polymer scaffold as a biocompatible antibacterial system

A chronic nonhealing wound poses a significant risk for infection and subsequent health complications, potentially endangering the patient‘s well-being. Therefore, effective wound dressings must meet several crucial criteria, including: (1) eliminating bacterial pathogen growth within the wound, (2) forming a barrier against airborne microbes, (3) promoting cell proliferation, (4) facilitating tissue repair. In this study, we synthesized 8 ± 3 nm Ag NP with maleic acid and incorporated them into an electrospun polycaprolactone (PCL) matrix with 1.6 and 3.4 µm fiber sizes. The Ag NPs were anchored to the matrix via electrospraying water-soluble poly(vinyl) alcohol (PVA), reducing the average sphere size from 750 to 610 nm in the presence of Ag NPs. Increasing the electrospraying time of Ag NP-treated PVA spheres demonstrated a more pronounced antibacterial effect. The resultant silver-based material exhibited 100% inhibition of gram-negative Escherichia coli and gram-positive Staphylococcus aureus growth within 6 h while showing non-cytotoxic effects on the Vero cell line. We mainly discuss the preparation method aspects of the membrane, its antibacterial properties, and cytotoxicity, suggesting that combining these processes holds promise for various medical applications.

Glycosyl transferase GT2 genes mediate the biosynthesis of an unusual (1,3;1,4)-β-glucan exopolysaccharide in the bacterium Sarcina ventriculi.

Linear, unbranched (1,3;1,4)-β-glucans (mixed-linkage glucans or MLGs) are commonly found in the cell walls of grasses, but have also been detected in basal land plants, algae, fungi and bacteria. Here we show that two family GT2 glycosyltransferases from the Gram-positive bacterium Sarcina ventriculi are capable of synthesizing MLGs. Immunotransmission electron microscopy demonstrates that MLG is secreted as an exopolysaccharide, where it may play a role in organizing individual cells into packets that are characteristic of Sarcina species. Heterologous expression of these two genes shows that they are capable of producing MLGs in planta, including an MLG that is chemically identical to the MLG secreted from S. ventriculi cells but which has regularly spaced (1,3)-β-linkages in a structure not reported previously for MLGs. The tandemly arranged, paralogous pair of genes are designated SvBmlgs1 and SvBmlgs2. The data indicate that MLG synthases have evolved different enzymic mechanisms for the incorporation of (1,3)-β- and (1,4)-β-glucosyl residues into a single polysaccharide chain. Amino acid variants associated with the evolutionary switch from (1,4)-β-glucan (cellulose) to MLG synthesis have been identified in the active site regions of the enzymes. The presence of MLG synthesis in bacteria could prove valuable for large-scale production of MLG for medical, food and beverage applications.

Investigating the impact of data heterogeneity on the performance of federated learning algorithm using medical imaging.

In recent years, Federated Learning (FL) has gained traction as a privacy-centric approach in medical imaging. This study explores the challenges posed by data heterogeneity on FL algorithms, using the COVIDx CXR-3 dataset as a case study. We contrast the performance of the Federated Averaging (FedAvg) algorithm on non-identically and independently distributed (non-IID) data against identically and independently distributed (IID) data. Our findings reveal a notable performance decline with increased data heterogeneity, emphasizing the need for innovative strategies to enhance FL in diverse environments. This research contributes to the practical implementation of FL, extending beyond theoretical concepts and addressing the nuances in medical imaging applications. This research uncovers the inherent challenges in FL due to data diversity. It sets the stage for future advancements in FL strategies to effectively manage data heterogeneity, especially in sensitive fields like healthcare.

Concerns of osteopathic medical students during the COVID-19 pandemic.

This study aims to quantify the areas of most concern in medical students in relation to their residency application in the setting of the COVID-19 pandemic and to identify risk factors for all that cause concern and specific areas of concern in a population with well-established high rates of anxiety at baseline. The COVID-19 pandemic introduced sweeping changes to medical education that had wide-ranging effects on medical students and their applications for medical residencies. In August 2020, we utilized a cross-sectional study to quantify student's areas of concern related to residency application related to the COVID-19 pandemic. We asked participants to rate their levels of concern in 15 different aspects related to medical residency applications and the perceived impact that COVID-19 had on each. The survey was distributed to 984 osteopathic medical students, with 255 complete responses. The three areas of greatest impact were shadowing opportunities (4.15), volunteer opportunities (4.09), and conferencing opportunities (4.09). The most salient demographic variables were year in school, sex, and locale. Females reported higher levels of concern across all categories in the study compared to males, with statistical significance across all categories (all p<0.05, Range d=0.16 to 0.43), except for letters of recommendation and sub-internships. The areas of most concern identified in our study were consistent with prior studies and may implicate the pressures that female medical students may feel compared to their male counterparts. The underlying cause(s) may be subject to future research.

Multi-objective optimization for vector quantization via genetic algorithm

The issue of image compression continues to be a subject of ongoing research within the domain of image processing, particularly in the context of medical applications. The quality of the decompressed image can vary depending on the accuracy of the compression technique, resulting in either fine or distorted details. Therefore, the diagnostic procedure performed by medical professionals is contingent upon the precision of the compression and decompression process. In addition, the compression of medical images serves to decrease the amount of storage required, thereby enabling faster transmission over computer networks through the reduction of their bit size. This paper proposes a hybrid mix of the discrete wavelet transform (DWT) technique and vector quantization (VQ) to improve the compression technique of medical images. The aim of the proposed compression technique is to preserve diagnostic image information while achieving a high compression ratio. First, noise in medical images is caused by salt pepper noise. At the same time, the edges of the images are maintained in sharpness and context. Then, a lossless compression method is applied to the wavelet coefficients of the subband with the lowest frequency, while the thresholding method was used to efficiently construct coefficients for high-frequency sub-bands. This process will produce a traditional VQ, which is estimated via the Genetic Algorithm (GA) with fuzzy clustering. While Arithmetic encoded theory was being utilized to quantize coefficients, the proposed compression technique was evaluated by dividing the image into two levels and three levels of sub-bands, respectively, in two different scenarios. Comparing the decompressed image to the filtered image by means of different evaluation metrics, the proposed method can enhance compression performance and strike a balance between compression ratio and image visual quality.

Modified Release 3D-Printed Capsules Containing a Ketoprofen Self-Nanoemulsifying System for Personalized Medical Application.

This study explores the realm of personalized medicine by investigating the utilization of 3D-printed dosage forms, specifically focusing on patient-specific enteric capsules designed for the modified release of ketoprofen, serving as a model drug. The research investigates two distinct scenarios: the modification of drug release from 3D-printed capsules crafted from hydroxypropyl methylcellulose phthalate:polyethylene glycol (HPMCP:PEG) and poly(vinyl alcohol) (PVA), tailored for pH sensitivity and delayed release modes, respectively. Additionally, a novel ketoprofen-loaded self-nanoemulsifying drug delivery system (SNEDDS) based on pomegranate seed oil (PSO) was developed, characterized, and employed as a fill material for the capsules. Through the preparation and characterization of the HPMCP:PEG based filament via the hot-melt extrusion method, the study thoroughly investigated its thermal and mechanical properties. Notably, the in vitro drug release analysis unveiled the intricate interplay between ketoprofen release, polymer type, and capsule thickness. Furthermore, the incorporation of ketoprofen into the SNEDDS exhibited an enhancement in its in vitro cylooxygenase-2 (COX-2) inhibitory activity. These findings collectively underscore the potential of 3D printing in shaping tailored drug delivery systems, thereby contributing significantly to the advancement of personalized medicine.

Polarity control of siloxane composite films for triboelectric nanogenerator based self-powered body temperature monitoring

Body temperature monitoring systems serve as key indicators for identifying potential patients with various illnesses such as influenza and COVID-19. Conventionally, these monitoring devices rely on batteries, limiting their long-term and widespread application. Self-powered thermometers are considered a sustainable solution that enable continuous monitoring. Among various self-charging power sources, triboelectric nanogenerators (TENGs) are a novel development, but suffer several critical drawbacks for medical applications. In this study, we present a high-performance TENG for self-powered body temperature monitoring systems by controlling the polarity of glass-fabric reinforced vinyl-thiol functionalized hybrid materials (GFR-VTHs) by varying the phenyl group contents. The effect of polarity modification on the performance of the developed TENG was confirmed by the high electrical output and stable operation under 10,000 cycles of repetitive pressing tests. Finally, self-powered body temperature monitoring systems were constructed by measuring human body temperature with a clinical thermometer powered by the GFR-VTH-based TENG, demonstrating device feasibility as a power source for self-powered healthcare systems.

Synthesis of Zinc Oxide and Silver Nanoparticles by Chemical Method, Study of Structure, Properties and Applications

Zinc and silver oxide nanoparticles are widely used in technology, science, cosmetology and medicine. Research objectives: to study the synthesis of zinc and silver oxide nanoparticles by a chemical method, to study the structure, properties and medical applications of synthesized nanoparticles. Synthesis of zinc oxide and silver nanoparticles performed using chemical method, which saves energy, temperature and the cost of expensive equipment. The synthesized zinc and silver oxide nanoparticles range in size from 17 to 26 nanometers. The skin-irritating effect of the medicinal cosmetic gel based on nanoparticles of zinc oxide and silver obtained by our method was not revealed.

Optofluidic Force Induction Meets Raman Spectroscopy and Inductively Coupled Plasma-Mass Spectrometry: A New Hyphenated Technique for Comprehensive and Complementary Characterizations of Single Particles.

Nanoparticles are produced at accelerating rates, are increasingly integrated into scientific and industrial applications, and are widely discharged into the environment. Analytical techniques are required to characterize parameters such as particle number concentrations, mass and size distributions, molecular and elemental compositions, and particle stability. This is not only relevant to investigate their utility for various industrial or medical applications and for controlling the manufacturing processes but also to assess toxicity and environmental fate. Different analytical strategies aim to characterize certain facets of particles but are difficult to combine to retrieve relevant parameters coherently and to provide a more comprehensive picture. In this work, we demonstrate the first online hyphenation of optofluidic force induction (OF2i) with Raman spectroscopy and inductively coupled plasma-time-of-flight-mass spectrometry (ICP-TOFMS) to harness their complementary technology-specific advantages and to promote comprehensive particle characterizations. We optically trapped individual particles on a weakly focused vortex laser beam by aligning a microfluidic flow antiparallelly to the laser propagation direction. The position of particles in this optical trap depended on the hydrodynamic diameter and therefore enabled size calibration as well as matrix elimination. Additionally, laser light scattered on particles was analyzed in a single particle (SP) Raman spectroscopy setup for the identification of particulate species and phases. Finally, particles were characterized regarding elemental composition and their distributions in mass and size using SP ICP-TOFMS. In a proof of concept, we analyzed polystyrene-based microplastic and TiO2 nanoparticles and demonstrated the opportunities provided through the coupling of OF2i with SP Raman and SP ICP-TOFMS.

Open-source graphical user interface for the creation of synthetic skeletons for medical image analysis

Open-source graphical user interface for the creation of synthetic skeletons for medical image analysis

Synthesis and characterization of hydroxyapatite nanoparticles from calcium hydroxide fouled with gases evolved from smokestack of glass industry

In glass industry, the evolved gases and fumes from burning the gas fuel absorbed in calcium hydroxide to minimize the pollution of environment. After a period of time, the calcium hydroxide fouled with sulphate and carbonate as action of the absorbed SO3 and CO2 gases. Based on our interest to treatment the solid waste materials, this study intended to convert the obtained waste of calcium hydroxide fouled with gases to valuable products. Firstly, this waste was treated with water, caustic soda and acids. The results confirmed the conversion of waste to pure calcium sulfate by treatment with 6 v/v% sulfuric acid. Secondly, the obtained calcium sulfate was reacted with ammonium dihydrogen phosphate solution for preparation of calcium hydroxyapatite (HAp) nanoparticles. The produced HAp sample was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and N2 adsorption measurements. The obtained findings confirmed that the HAp can be produced after calcination at 700 °C, nanorods-like of sizes ranged from 11 to 15 nm and with main surface functional groups of hydroxyapatite. TGA and DTA data indicated that HAp is thermally stable up to 700 °C. Also, the obtained HAp has Ca/P molar ratio of 1.60 and exhibited high total surface area of 146 m2/g with mesoporous structure which make this material can be used in medical and water purification applications.

Thermomechanical Pathways for Accurate Microstructural Control of Ti–7Ag Alloy: Towards a New Generation of Antibacterial Materials for Medical Applications

This study delved into exploring microstructural states in a Ti–7Ag alloy to achieve targeted functional and structural properties. Specifically, the focus was on attaining a homogeneously precipitated state and a solid solution, known for their potential to combine functional traits like corrosion resistance and antibacterial activity with structural properties such as mechanical strength. However, obtaining these optimized microstructures presents challenges due to kinetic considerations. A key finding of this study was the crucial role of a pre-deformation stage, prior to heat treatment, to create an even distribution of fine Ti2Ag precipitates. Moreover, we demonstrated that starting from this precipitated state, a controlled dissolution step could yield a single-phase solid solution with similar grain size. Therefore, a tailored set of thermomechanical treatments was developed to achieve both microstructures, and these metallurgical states were fully characterized combining SEM (BSE imaging and EDS analysis), TEM, and XRD. Associated mechanical properties were also assessed by tensile testing. In addition, the process was proven to be robust enough to overcome potential industrial problems, such as slow cooling rates when water-quenching large ingots. Considering the limited existing documentation on microstructural features in Ti–Ag alloys, this work on this model alloy significantly advanced our current understanding of the broader Ti–Ag alloy system by providing new data and showcasing a tailored approach involving thermomechanical treatments.

Shortcut learning in medical AI hinders generalization: method for estimating AI model generalization without external data

Healthcare datasets are becoming larger and more complex, necessitating the development of accurate and generalizable AI models for medical applications. Unstructured datasets, including medical imaging, electrocardiograms, and natural language data, are gaining attention with advancements in deep convolutional neural networks and large language models. However, estimating the generalizability of these models to new healthcare settings without extensive validation on external data remains challenging. In experiments across 13 datasets including X-rays, CTs, ECGs, clinical discharge summaries, and lung auscultation data, our results demonstrate that model performance is frequently overestimated by up to 20% on average due to shortcut learning of hidden data acquisition biases (DAB). Shortcut learning refers to a phenomenon in which an AI model learns to solve a task based on spurious correlations present in the data as opposed to features directly related to the task itself. We propose an open source, bias-corrected external accuracy estimate, PEst, that better estimates external accuracy to within 4% on average by measuring and calibrating for DAB-induced shortcut learning.

Recent Developments in Slippery Liquid-Infused Porous Surface Coatings for Biomedical Applications.

Slippery liquid-infused porous surface (SLIPS), inspired by the Nepenthes pitcher plant, exhibits excellent performances as it has a smooth surface and extremely low contact angle hysteresis. Biomimetic SLIPS attracts considerable attention from the researchers for different applications in self-cleaning, anti-icing, anticorrosion, antibacteria, antithrombotic, and other fields. Hence, SLIPS has shown promise for applications across both the biomedical and industrial fields. However, the manufacturing of SLIPS with strong bonding ability to different substrates and powerful liquid locking performance remains highly challenging. In this review, a comprehensive overview of research on SLIPS for medical applications is conducted, and the design parameters and common fabrication methods of such surfaces are summarized. The discussion extends to the mechanisms of interaction between microbes, cells, proteins, and the liquid layer, highlighting the typical antifouling applications of SLIPS. Furthermore, it identifies the potential of utilizing the controllable factors provided by SLIPS to develop innovative materials and devices aimed at enhancing human health.

Research Progress on Taxus Extraction and Formulation Preparation Technologies.

Taxus, as a globally prevalent evergreen tree, contains a wealth of bioactive components that play a crucial role in the pharmaceutical field. Taxus extracts, defined as a collection of one or more bioactive compounds extracted from the genus Taxus spp., have become a significant focus of modern cancer treatment research. This review article aims to delve into the scientific background of Taxus extracts and their considerable value in pharmaceutical research. It meticulously sifts through and compares various advanced extraction techniques such as supercritical extraction, ultrasound extraction, microwave-assisted extraction, solid-phase extraction, high-pressure pulsed electric field extraction, and enzymatic extraction, assessing each technology's advantages and limitations across dimensions such as extraction efficiency, extraction purity, economic cost, operational time, and environmental impact, with comprehensive analysis results presented in table form. In the area of drug formulation design, this paper systematically discusses the development strategies for solid, liquid, and semi-solid dosage forms based on the unique physicochemical properties of Taxus extracts, their intended medical uses, and specific release characteristics, delving deeply into the selection of excipients and the critical technical issues in the drug preparation process. Moreover, the article looks forward to the potential directions of Taxus extracts in future research and medical applications, emphasizing the urgency and importance of continuously optimizing extraction methods and formulation design to enhance treatment efficacy, reduce production costs, and decrease environmental burdens. It provides a comprehensive set of preparation techniques and formulation optimization schemes for researchers in cancer treatment and other medical fields, promoting the application and development of Taxus extracts in pharmaceutical sciences.

Self-Assembled Hydrogel Membranes with Structurally Tunable Mechanical and Biological Properties.

Using supramolecular self-assembled nanocomposite materials made from protein and polysaccharide components is becoming more popular because of their unique properties, such as biodegradability, hierarchical structures, and tunable multifunctionality. However, the fabrication of these materials in a reproducible way remains a challenge. This study presents a new evaporation-induced self-assembly method producing layered hydrogel membranes (LHMs) using tropocollagen grafted by partially deacetylated chitin nanocrystals (CO-g-ChNCs). ChNCs help stabilize tropocollagen's helical conformation and fibrillar structure by forming a hierarchical microstructure through chemical and physical interactions. The LHMs show improved mechanical properties, cytocompatibility, and the ability to control drug release using octenidine dihydrochloride (OCT) as a drug model. Because of the high synergetic performance between CO and ChNCs, the modulus, strength, and toughness increased significantly compared to native CO. The biocompatibility of LHM was tested using the normal human dermal fibroblast (NHDF) and the human osteosarcoma cell line (Saos-2). Cytocompatibility and cell adhesion improved with the introduction of ChNCs. The extracted ChNCs are used as a reinforcing nanofiller to enhance the performance properties of tropocollagen hydrogel membranes and provide new insights into the design of novel LHMs that could be used for various medical applications, such as control of drug release in the skin and bone tissue regeneration.

Design of a spherical parallel mechanism with controllable center of rotation using a spherical reconfiguration linkage

It is well known that Remote Center of the motion (RCM) mechanisms are highly suitable for many medical applications. While it is sometimes preferable that the mechanism can control their Center of Rotation (CoR), most RCM mechanisms do not have this possibility without being mounted on large and heavy translational platforms. By using a new concept of Spherical Reconfigurable Linkage (SRL), the present study offers an alternative solution. These new linkages are designed to control their radius and they are connected to form an RCM mechanism with controllable CoR. The newly mounted mechanism now has two linear Degrees of Freedom (DoF) for the displacement of its CoR in addition to its two angular DoF. The linear kinematic model is derived along with the angular kinematic one while taking into account the reconfiguration of the SRL. The velocity model is calculated and all singular configurations are identified. The mechanism performances in terms of workspace and kinematic performances are is also assessed. Finally, motion capture experiments on a prototype validated the models.

Essential oils from fennel plants as valuable chemical products: gas chromatography–mass spectrometry, FTIR, quantum mechanical investigation, and antifungal activity

AbstractIn the present study, the biomass produced by fennel plants (Foeniculum vulgare Mill.) was converted to yield bioactive chemicals, and the hydrodistillation method was used to extract the essential oils (EOs) from both the leaves and the umbels. The antifungal activity of the EOs was tested using bioassay against the development of Fusarium oxysporum MW854649 and Alternaria solani MT279570. Molecular spectroscopic detection techniques were used to evaluate the EO products using gas chromatography–mass spectrometer (GC–MS) and Fourier transform infrared spectroscopy (FTIR). GC–MS equipped with single quadruple analyzers have been used to measure the electron ionization (EI) mass spectra of the primary constituents of fennel EOs at 70 eV. The main chemical compounds in the EO from leaves were anethole, estragole, D-limonene, trans-β-ocimene, and fenchone, with percentages of 37.94, 35.56, 17.46, 1.53, and 1.49%, respectively. The abundant compounds in the EO from umbels were estragole, anethole, D-limonene, fenchone, and γ-terpinene, with percentages of 51.18, 25.08, 12.22, 6.57, and 2.86%, respectively. EI mass spectral fragmentation of the major compounds D-limonene, estragole, anethole, and fenchone has been investigated. Umbels and leaf EOs at 5000 mg/L displayed the strongest suppression of fungal growth against A. solani, with values of 87.78% and 79.63%, respectively, compared to the positive control (94.44%). The EOs from umbels and leaves at 5000 mg/L showed the highest inhibition of fungal growth against F. oxysprium as compared to the positive control (94.44%), with values of 77.77% and 72.96%, respectively. All of the important ions—including a few distinctive fragment ions—have comprehensive fragmentation pathways defined. Based on EI, the main routes of fragmentation for the primary compounds have been identified. The existence of alkenes, aliphatic alcohols, ethers, carboxylic acids, ester compounds, alkanes, hydrogen-bonded alcohols, and phenols was demonstrated by the FTIR analysis of fennel EOs. On the other hand, the reactive behavior of the studied molecules has been investigated using two quantum mechanics method: the modified neglect of diatomic overlap (MNDO), a semi-empirical method, and the density functional theory (DFT)/B3LYP hybrid density functional method with the 6-311G (d, p) basis set in the ground state for gas phase. The optimum geometries have been obtained through the execution of computations and electrostatic potential. The obtained analytical and calculated results were then used to understand the activity of the studied EOs in further medical applications.