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ACS Omega Aug 2023Characterizing the strength of a solid-liquid interface can be done by depositing a single drop of liquid on a planar solid surface and measuring the angle of the formed...
Characterizing the strength of a solid-liquid interface can be done by depositing a single drop of liquid on a planar solid surface and measuring the angle of the formed semicircle, called the contact angle. The contact angle of pure water is indicative of a surface's hydrophobicity and is a useful metric in biomedical applications such as tissue scaffolding and drug/tissue interactions. However, the roughness and inhomogeneity of most biological surfaces make obtaining accurate contact angles of such materials challenging. Here, we developed an instrument and methodology to obtain contact angles of tissue sections. Breast cancer tumor and nearby healthy tissue sections were used as the model biological surface. The custom instrument was built on existing equipment by improving drop dispensing accuracy in the nanoliter range, an XYZ stage, additional side view cameras, and microscope-based sample visualization. The method takes into account the inherent surface inhomogeneity and topology of tissue and the required method of illumination for contact angle acquisition. As such, the system uses an inverted microscope with a high sensitivity camera, an XYZ stage for accurate droplet placement on tissue, and multiple cameras to obtain contact angles around the entire perimeter of the drop. We tested the system with breast cancer biopsies and adjacent normal tissue from 75 patients and report here a trend of tumor exhibiting higher water contact angles, and thus higher hydrophobicity, compared to their respective normal adjacent tissue. The system described here can be used to characterize any type of biological tissue, which can be sectioned, with any liquid including water or solutions with dissolved or suspended therapeutic molecules and particles.
PubMed: 37546668
DOI: 10.1021/acsomega.3c01792 -
Clinical, Cosmetic and Investigational... 2023To compare epidermal biophysical properties, indicators of epidermal function, in individuals with and without primary cutaneous amyloidosis (PCA).
PURPOSE
To compare epidermal biophysical properties, indicators of epidermal function, in individuals with and without primary cutaneous amyloidosis (PCA).
PATIENTS AND METHODS
This study incorporated 189 patients with PCA and 166 healthy individuals. The GPSkin Barrier was employed to measure transepidermal water loss (TEWL) rates and hydration levels of the stratum corneum. The Sebumeter and the Skin pH Meter were utilized to determine the skin surface's sebum content and pH, respectively. The severity of pruritus in participants was evaluated using the visual analog scale (VAS).
RESULTS
Compared to the control group without PCA, individuals with PCA displayed a notable increase in skin surface pH and TEWL and a decrease in the hydration levels of the stratum corneum (<0.0001 for all parameters). Additionally, the sebum content was markedly lower in those with PCA than in the controls (<0.0001). Of particular note, both TEWL and skin surface pH at the lesion sites on the back and the shin were more elevated in lichenoid amyloidosis (LA) and in macular amyloidosis (MA), whereas hydration levels of the stratum corneum and sebum levels were diminished in LA compared to MA (<0.05). In conclusion, both hydration levels of the stratum corneum and sebum content exhibited an inverse relationship with pruritus severity, whereas TEWL and skin surface pH demonstrated a positive correlation with pruritus intensity.
CONCLUSION
The function of the epidermis is compromised in individuals diagnosed with PCA. However, the mechanisms underlying these changes await further investigation.
PubMed: 37953856
DOI: 10.2147/CCID.S426209 -
Physical Review Letters Jun 2022Pattern dynamics on curved surfaces are found everywhere in nature. The geometry of surfaces has been shown to influence dynamics and play a functional role, yet a...
Pattern dynamics on curved surfaces are found everywhere in nature. The geometry of surfaces has been shown to influence dynamics and play a functional role, yet a comprehensive understanding is still elusive. Here, we report for the first time that a static Turing pattern on a flat surface can propagate on a curved surface, as opposed to previous studies, where the pattern is presupposed to be static irrespective of the surface geometry. To understand such significant changes on curved surfaces, we investigate reaction-diffusion systems on axisymmetric curved surfaces. Numerical and theoretical analyses reveal that both the symmetries of the surface and pattern participate in the initiation of pattern propagation. This study provides a novel and generic mechanism of pattern propagation that is caused by surface curvature, as well as insights into the general role of surface geometry.
Topics: Diffusion; Models, Theoretical
PubMed: 35714259
DOI: 10.1103/PhysRevLett.128.224101 -
Biosensors Apr 2023Recently, hydrogels have attracted great attention because of their unique properties, including stretchability, self-adhesion, transparency, and biocompatibility. They... (Review)
Review
Recently, hydrogels have attracted great attention because of their unique properties, including stretchability, self-adhesion, transparency, and biocompatibility. They can transmit electrical signals for potential applications in flexible electronics, human-machine interfaces, sensors, actuators, et al. MXene, a newly emerged two-dimensional (2D) nanomaterial, is an ideal candidate for wearable sensors, benefitting from its surface's negatively charged hydrophilic nature, biocompatibility, high specific surface area, facile functionalization, and high metallic conductivity. However, stability has been a limiting factor for MXene-based applications, and fabricating MXene into hydrogels has been proven to significantly improve their stability. The unique and complex gel structure and gelation mechanism of MXene hydrogels require intensive research and engineering at nanoscale. Although the application of MXene-based composites in sensors has been widely studied, the preparation methods and applications of MXene-based hydrogels in wearable electronics is relatively rare. Thus, in order to facilitate the effective evolution of MXene hydrogel sensors, the design strategies, preparation methods, and applications of MXene hydrogels for flexible and wearable electronics are comprehensively discussed and summarized in this work.
Topics: Humans; Hydrogels; Electric Conductivity; Electronics; Wearable Electronic Devices
PubMed: 37232856
DOI: 10.3390/bios13050495 -
The Journal of Physical Chemistry. B Jul 2023The formation of ice, which plays an important role in diverse contexts ranging from cryopreservation to atmospheric science, is often mediated by solid surfaces....
The formation of ice, which plays an important role in diverse contexts ranging from cryopreservation to atmospheric science, is often mediated by solid surfaces. Although surfaces that interact favorably with ice (relative to liquid water) can facilitate ice formation by lowering nucleation barriers, the molecular characteristics that confer icephilicity to a surface are complex and incompletely understood. To address this challenge, here we introduce a robust and computationally efficient method for characterizing surface ice-philicity that combines molecular simulations and enhanced sampling techniques to quantify the free energetic cost of increasing surface-ice contact at the expense of surface-water contact. Using this method to characterize the ice-philicity of a family of model surfaces that are lattice matched with ice but vary in their polarity, we find that the nonpolar surfaces are moderately ice-phobic, whereas the polar surfaces are highly ice-philic. In contrast, for surfaces that display no complementarity to the ice lattice, we find that ice-philicity is independent of surface polarity and that both nonpolar and polar surfaces are moderately ice-phobic. Our work thus provides a prescription for quantitatively characterizing surface ice-philicity and sheds light on how ice-philicity is influenced by lattice matching and polarity.
PubMed: 37378637
DOI: 10.1021/acs.jpcb.3c01627 -
Cancer Letters Apr 2024Cancer remains a leading global cause of mortality, demanding early diagnosis and effective treatment. Traditional therapeutic methods often fall short due to their need... (Review)
Review
Cancer remains a leading global cause of mortality, demanding early diagnosis and effective treatment. Traditional therapeutic methods often fall short due to their need for more specificity and systemic toxicity. In this challenging landscape, nanodiamonds (ND) emerge as a potential solution, mitigating the limitations of conventional approaches. ND are tiny carbon particles that mimic traditional diamonds chemical stability and hardness and harness nanomaterials' advantages. ND stands out for the unique properties that make them promising nanotheranostics candidates, combining therapeutic and imaging capabilities in one platform. Many of these applications depend on the design of the particle's surface, as the surface's role is crucial in transporting bioactive molecules, preventing aggregation, and building composite materials. This review delves into ND's distinctive features, structural and optical characteristics, and their profound relevance in advancing cancer diagnosis and treatment methods. The report delves into how these exceptional ND properties drive the development of state-of-the-art techniques for precise tumor targeting, boosting the effectiveness of chemotherapy as a chemosensitizer, harnessing immunotherapy strategies, facilitating precision medicine, and creating localized microfilm devices for targeted therapies.
Topics: Humans; Nanodiamonds; Precision Medicine; Drug Delivery Systems; Neoplasms; Diagnostic Imaging
PubMed: 38369006
DOI: 10.1016/j.canlet.2024.216710 -
Proteins Sep 2022The structure of a protein plays a pivotal role in determining its function. Often, the protein surface's shape and curvature dictate its nature of interaction with...
The structure of a protein plays a pivotal role in determining its function. Often, the protein surface's shape and curvature dictate its nature of interaction with other proteins and biomolecules. However, marked by corrugations and roughness, a protein's surface representation poses significant challenges for its curvature-based characterization. In the present study, we employ unsupervised machine learning to segment the protein surface into patches. To measure the surface curvature of a patch, we present an algebraic sphere fitting method that is fast, accurate, and robust. Moreover, we use local curvatures to show the existence of "shape complementarity" in protein-protein, antigen-antibody, and protein-ligand interfaces. We believe that the current approach could help understand the relationship between protein structure and its biological function and can be used to find binding partners of a given protein.
Topics: Algorithms; Ligands; Models, Molecular; Proteins; Unsupervised Machine Learning
PubMed: 35429198
DOI: 10.1002/prot.26345 -
Materials (Basel, Switzerland) Jun 2022Several components are made from Al-Mg-based composites. MoS is used to increase the composite's machinability. Different weight percent (3, 4, and 5) of MoS are added...
Several components are made from Al-Mg-based composites. MoS is used to increase the composite's machinability. Different weight percent (3, 4, and 5) of MoS are added as reinforcement to explore the machinability properties of Al-Mg-reinforced composites. The wire cut electrical discharge machining (WEDM) process is used to study the machinability characteristics of the fabricated Al-Mg-MoS composite. The machined surface's roughness and overcut under different process conditions are discussed. The evaluation-based distance from average solution (EDAS) method is used to identify the optimal setting to get the desired surface roughness and overcut. The following WEDM process parameters are taken to determine the impact of peak current, pulse on time, and gap voltage on surface roughness, and overcut. The WEDM tests were carried out on three different reinforced samples to determine the impact of reinforcement on surface roughness and overcut. The surface roughness and overcut increase as the reinforcement level increases, but the optimal parameters for all three composites are the same. According to EDAS analysis, I, Ton, and V are the best conditions. Furthermore, peak current and pulse on-time significantly influence surface roughness and overcut.
PubMed: 35806680
DOI: 10.3390/ma15134548 -
Frontiers in Chemistry 2020Bioinspired superhydrophobic surfaces are an artificial functional surface that mainly extracts morphological designs from natural organisms. In both laboratory research... (Review)
Review
Bioinspired superhydrophobic surfaces are an artificial functional surface that mainly extracts morphological designs from natural organisms. In both laboratory research and industry, there is a need to develop ways of giving large-area surfaces water repellence. Currently, surface modification methods are subject to many challenging requirements such as a need for chemical-free treatment or high surface roughness. Laser micro-nanofabrications are a potential way of addressing these challenges, as they involve non-contact processing and outstanding patterning ability. This review briefly discusses multiple laser patterning methods, which could be used for surface structuring toward creating superhydrophobic surfaces.
PubMed: 33195040
DOI: 10.3389/fchem.2020.00835 -
Translational Vision Science &... Nov 2020Dichotomies are double-edged: they can simplify and enlighten as well as exaggerate and entangle. Seeing the eye as anterior segment vs. posterior segment simplifies the...
Dichotomies are double-edged: they can simplify and enlighten as well as exaggerate and entangle. Seeing the eye as anterior segment vs. posterior segment simplifies the formidable task of dissecting the function of the eye. Yet this view creates artificial divisions in a coherent whole. Clearly, vision requires the convergence of the light refractive function of the front of the eye with the light sensing function of the back of the eye. The National Eye Institute has long aimed to foster research across the visual pathway. Finding the right balance is a constant work in progress. A recently held scientific meeting which we co-organized with the United States Army Medical Research Institute of Chemical Defense, offered an opportunity to take stock of what the anterior segment in general, and the ocular surface in particular, bring to our understanding of biology and disease of the eye. Multiple dichotomies surfaced: acute vs. chronic disease; epithelial vs. endothelial damage; fibrotic vs. vascular pathology; inflammation vs. resolution response; chemical exposure vs. countermeasure; monotherapy vs. combination therapy; mechanistic vs. exploratory research; human vs. animal model. Merging some of these dichotomies is the goal of this paper.
Topics: Animals; Anterior Eye Segment; Humans; United States
PubMed: 33200045
DOI: 10.1167/tvst.9.12.3