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Heliyon Jun 2023The transmission of viruses is largely dependent on contact with contaminated virus-laden communal surfaces. While frequent surface disinfection and antiviral coating... (Review)
Review
The transmission of viruses is largely dependent on contact with contaminated virus-laden communal surfaces. While frequent surface disinfection and antiviral coating techniques are put forth by researchers as a plan of action to tackle transmission in dire situations like the Covid-19 pandemic caused by SARS-CoV-2 virus, these procedures are often laborious, time-consuming, cost-intensive, and toxic. Hence, surface topography-mediated antiviral surfaces have been gaining more attention in recent times. Although bioinspired hydrophobic antibacterial nanopatterned surfaces mimicking the natural sources is a very prevalent and successful strategy, the antiviral prospect of these surfaces is yet to be explored. Few recent studies have explored the potential of nanopatterned antiviral surfaces. In this review, we highlighted surface properties that have an impact on virus attachment and persistence, particularly focusing and emphasizing on the prospect of the nanotextured surface with enhanced properties to be used as antiviral surface. In addition, recent developments in surface nanopatterning techniques depending on the nano-scaled dimensions have been discussed. The impacts of environments and surface topology on virus inactivation have also been reviewed.
PubMed: 37260884
DOI: 10.1016/j.heliyon.2023.e16698 -
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 -
Acta Biomaterialia Jan 2023Cyanobacteria respond to light stimulation, activating localised assembly of type IV pili for motility. The resulting phototactic response is highly dependent on the...
Cyanobacteria respond to light stimulation, activating localised assembly of type IV pili for motility. The resulting phototactic response is highly dependent on the nature of the incoming light stimulus, and the final motility parameters depend on the surface properties. Conventionally, phototaxis studies are carried out on hydrogel surfaces, such as agarose, with surface properties that vary in time due to experimental conditions. This study considers five substrates, widely utilized in microfluidic technology, to identify the most suitable alternative for performing reliable and repeatable phototaxis assays. The surfaces are characterised via a contact angle goniometer to determine the surface energy, white light interferometry for roughness, zeta-potentials and AFM force distance curves for charge patterns, and XPS for surface composition. Cell motility assays showed 1.25 times increment on surfaces with a water contact angle of 80° compared to a reference glass surface. To prove that motility can be enhanced, polydimethylsiloxane (PDMS) surfaces were plasma treated to alter their surface wettability. The motility on the plasma-treated PDMS showed similar performance as for glass surfaces. In contrast, untreated PDMS surfaces displayed close to zero motility. We also describe the force interactions of cells with the test surfaces using DLVO (Derjaguin-Landau-Verwey-Overbeek) and XDLVO (extended DLVO) theories. The computed DLVO/XDLVO force-distance curves are compared with those obtained using atomic force microscopy. Our findings show that twitching motility on tested surfaces can be described mainly from adhesive forces and hydrophobicity/hydrophilicity surface properties. STATEMENT OF SIGNIFICANCE: The current article focuses on unravelling the potential Micro-Electro-Mechanical System (MEMS) compatible surfaces for studying phototactic twitching motility of cyanobacteria. This is the first exhaustive surface characterization study coupled with phototaxis experiments, to understand the forces contributing to twitching motility. The methods shown in this paper can be further extended to study other surfaces and also to other bacteria exhibiting twitching motility.
Topics: Phototaxis; Surface Properties; Wettability; Hydrophobic and Hydrophilic Interactions; Cyanobacteria
PubMed: 36280031
DOI: 10.1016/j.actbio.2022.10.035 -
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 -
Computational and Structural... Dec 2024The study of protein molecular surfaces enables to better understand and predict protein interactions. Different methods have been developed in computer vision to...
The study of protein molecular surfaces enables to better understand and predict protein interactions. Different methods have been developed in computer vision to compare surfaces that can be applied to protein molecular surfaces. The present work proposes a method using the Wave Kernel Signature: Protein LOcal Surficial Similarity Screening (PLO3S). The descriptor of the PLO3S method is a local surface shape descriptor projected on a unit sphere mapped onto a 2D plane and called Surface Wave Interpolated Maps (SWIM). PLO3S allows to rapidly compare protein surface shapes through local comparisons to filter large protein surfaces datasets in protein structures virtual screening protocols.
PubMed: 38189058
DOI: 10.1016/j.csbj.2023.12.002 -
Frontiers in Bioengineering and... 2021Biofilms are structured microbial communities attached to surfaces, which play a significant role in the persistence of biofoulings in both medical and industrial... (Review)
Review
Biofilms are structured microbial communities attached to surfaces, which play a significant role in the persistence of biofoulings in both medical and industrial settings. Bacteria in biofilms are mostly embedded in a complex matrix comprised of extracellular polymeric substances that provide mechanical stability and protection against environmental adversities. Once the biofilm is matured, it becomes extremely difficult to kill bacteria or mechanically remove biofilms from solid surfaces. Therefore, interrupting the bacterial surface sensing mechanism and subsequent initial binding process of bacteria to surfaces is essential to effectively prevent biofilm-associated problems. Noting that the process of bacterial adhesion is influenced by many factors, including material surface properties, this review summarizes recent works dedicated to understanding the influences of surface charge, surface wettability, roughness, topography, stiffness, and combination of properties on bacterial adhesion. This review also highlights other factors that are often neglected in bacterial adhesion studies such as bacterial motility and the effect of hydrodynamic flow. Lastly, the present review features recent innovations in nanotechnology-based antifouling systems to engineer new concepts of antibiofilm surfaces.
PubMed: 33644027
DOI: 10.3389/fbioe.2021.643722 -
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 -
Journal of Functional Biomaterials Apr 2024Zirconia ceramic implants are commercially available from a rapidly growing number of manufacturers. Macroscopic and microscopic surface design and characteristics are... (Review)
Review
Zirconia ceramic implants are commercially available from a rapidly growing number of manufacturers. Macroscopic and microscopic surface design and characteristics are considered to be key determining factors in the success of the osseointegration process. It is, therefore, crucial to assess which surface modification promotes the most favorable biological response. The purpose of this study was to conduct a comparison of modern surface modifications that are featured in the most common commercially available zirconia ceramic implant systems. A review of the currently available literature on zirconia implant surface topography and the associated bio-physical factors was conducted, with a focus on the osseointegration of zirconia surfaces. After a review of the selected articles for this study, commercially available zirconia implant surfaces were all modified using subtractive protocols. Commercially available ceramic implant surfaces were modified or enhanced using sandblasting, acid etching, laser etching, or combinations of the aforementioned. From our literature review, laser-modified surfaces emerged as the ones with the highest surface roughness and bone-implant contact (BIC). It was also found that surface roughness could be controlled to achieve optimal roughness by modifying the laser output power during manufacturing. Furthermore, laser surface modification induced a very low amount of preload microcracks in the zirconia. Osteopontin (OPN), an early-late osteogenic differentiation marker, was significantly upregulated in laser-treated surfaces. Moreover, surface wettability was highest in laser-treated surfaces, indicating favorable hydrophilicity and thus promoting early bone forming, cell adhesion, and subsequent maturation. Sandblasting followed by laser modification and sandblasting followed by acid etching and post-milling heat treatment (SE-H) surfaces featured comparable results, with favorable biological responses around zirconia implants.
PubMed: 38667548
DOI: 10.3390/jfb15040091 -
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 -
Diving and Hyperbaric Medicine Sep 2023There is an increasing interest in 'transfer under pressure' (TUP) decompression in commercial diving, bridging traditional surface-oriented diving and saturation...
BACKGROUND
There is an increasing interest in 'transfer under pressure' (TUP) decompression in commercial diving, bridging traditional surface-oriented diving and saturation diving. In TUP diving the diver is surfaced in a closed bell and transferred isobarically to a pressure chamber for final decompression to surface pressure.
METHODS
Tables for air diving and air and oxygen decompression have been compared for total decompression time (TDT), oxygen breathing time as well as high and low gradient factors (GF high and low). These have been considered surrogate outcome measures of estimated decompression sickness probability (P).
RESULTS
Six decompression tables from DadCoDat (DCD, The Netherlands), Defence and Civil Institute of Environmental Medicine (DCIEM, Canada), Comex MT92 tables (France) and the United States Navy (USN) have been compared. In general, USN and DCD procedures advised longer TDT and oxygen breathing time and had a lower GF high compared to MT92 and DCIEM tables. GF low was significantly higher in USN procedures compared to DCD and one of the MT92 tables due to a shallower first stop in many USN profiles compared to the two others. Allowance and restrictions for repetitive diving varied extensively between the six procedures. While USN procedures have been risk-assessed by probabilistic models, no detailed documentation is available for any of the tables regarding validation in experimental and operational diving.
CONCLUSIONS
Absence of experimental testing of the candidate tables precludes firm conclusions regarding differences in P. All candidate tables are recognised internationally as well as within their national jurisdictions, and final decisions on procedure preference may depend on factors other than estimated P. USN and DCD procedures would be expected to have lower P than MT92 and DCIEM procedures, but the magnitude of these differences is not known.
Topics: Humans; Diving; Canada; Netherlands; Oxygen; Decompression
PubMed: 37718292
DOI: 10.28920/dhm53.3.189-202