Biomarkers In Saliva Research Articles

Aptamers in dentistry: diagnosis, therapeutics, and future perspectives.

Oral health is essential to general health. The diagnosis of dental diseases and treatment planning of dental care need to be straightforward and accurate. Recent studies have reported the use of aptamers in dentistry to achieve a simple diagnosis and facilitate therapy. Aptamers comprise nucleic acid sequences that possess a strong affinity for their target. Synthesized chemically, aptamers have several advantages, including smaller size, higher stability, and lower immunogenicity compared with monoclonal antibodies. They can be used to detect biomarkers in saliva and the presence of various pathogens, or can be used as a targeted drug delivery system for disease treatment. This review highlights current research on aptamers for dental care, especially the recent progress in oral disease diagnosis and therapeutics. The challenges and unresolved problems faced by the clinical use of aptamers are also discussed. In the future, the clinical applications of aptamers will be further extended to include, for example, dental indications and regenerative dentistry.

A salivary urea sensor based on a microsieve disposable gate AlGaN/GaN high electron mobility transistor.

The abundant bio-markers in saliva provide a new option for non-invasive testing. However, due to the presence of impurities in the saliva background, most of the existing saliva testing methods rely on pre-processing, which limits the application of saliva testing as a convenient means of testing in daily life. Herein, a disposable-gate AlGaN/GaN high electron mobility transistor (HEMT) biosensor integrated with a micro-sieve was introduced to solve the problem of signal interference caused by charged impurities in saliva for HEMT based biosensors, where the micro-sieve was utilized as a pre-treatment unit to remove large particles of impurities from saliva through the size effect and thus greatly improving the accuracy of detection. The experimental results showed that the HEMT based biosensor has excellent linearity (R2 = 0.9977) and a high sensitivity of 6.552 μA dec-1 for urea sensing from 1 fM to 100 mM in 0.1× PBS solution. When it comes to artificial saliva detection, compared to the HEMT sensor without the micro-sieve (sensitivity = 3.07432 μA dec-1), the sensitivity of the HEMT sensor integrated with the micro-sieve showed almost no change. Moreover, to verify that urea can be detected in actual saliva, urea is sensed directly in human saliva. The addition of the microsieve module provides a new way for biosensors to detect specific markers in saliva in real time, and the designed HEMT biosensor with the microsieve function has a wide range of application potential in rapid saliva detection.

Sputum production and salivary microbiome in COVID-19 patients reveals oral-lung axis.

SARS-CoV-2, a severe respiratory disease primarily targeting the lungs, was the leading cause of death worldwide during the pandemic. Understanding the interplay between the oral microbiome and inflammatory cytokines during acute infection is crucial for elucidating host immune responses. This study aimed to explore the relationship between the oral microbiome and cytokines in COVID-19 patients, particularly those with and without sputum production. Saliva and blood samples from 50 COVID-19 patients were subjected to 16S ribosomal RNA gene sequencing for oral microbiome analysis, and 65 saliva and serum cytokines were assessed using Luminex multiplex analysis. The Mann-Whitney test was used to compare cytokine levels between individuals with and without sputum production. Logistic regression machine learning models were employed to evaluate the predictive capability of oral microbiome, salivary, and blood biomarkers for sputum production. Significant differences were observed in the membership (Jaccard dissimilarity: p = 0.016) and abundance (PhILR dissimilarity: p = 0.048; metagenomeSeq) of salivary microbial communities between patients with and without sputum production. Seven bacterial genera, including Prevotella, Streptococcus, Actinomyces, Atopobium, Filifactor, Leptotrichia, and Selenomonas, were more prevalent in patients with sputum production (p<0.05, Fisher's exact test). Nine genera, including Prevotella, Megasphaera, Stomatobaculum, Selenomonas, Leptotrichia, Veillonella, Actinomyces, Atopobium, and Corynebacteria, were significantly more abundant in the sputum-producing group, while Lachnoanaerobaculum was more prevalent in the non-sputum-producing group (p<0.05, ANCOM-BC). Positive correlations were found between salivary IFN-gamma and Eotaxin2/CCL24 with sputum production, while negative correlations were noted with serum MCP3/CCL7, MIG/CXCL9, IL1 beta, and SCF (p<0.05, Mann-Whitney test). The machine learning model using only oral bacteria input outperformed the model that included all data: blood and saliva biomarkers, as well as clinical and demographic variables, in predicting sputum production in COVID-19 subjects. The performance metrics were as follows, comparing the model with only bacteria input versus the model with all input variables: precision (95% vs. 75%), recall (100% vs. 50%), F1-score (98% vs. 60%), and accuracy (82% vs. 66%).

Electrocatalytic FeFe2O4 embedded, spermine-imprinted polypyrrole (Fe/MIPpy) nanozymes for cancer diagnosis and prognosis.

Developing synthetic materials, with enzyme-like molecular recognition capabilities, as functional receptors in electronic or electrochemical devices for the timely diagnosis of major diseases is a great challenge. Herein, we present the development of Fe/MIPpy nanozymes, characterized as enzyme-like artificial receptors, for the precise and non-invasive monitoring of cancer biomarkers in aqueous solutions and human saliva. Through the integration of PVA-stabilized FeFe2O4 nanocrystals in a molecularly imprinted conducting polypyrrole matrix, the Fe/MIPpy nanozymes demonstrate 424 nA cm-2 nM-1 sensitivity and 220 pM detection limit. Charge-transfer mechanisms, Fe/MIPpy-spermine interactions, and the principle of spermine recognition are investigated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The disposable Fe/MIPpy sensor operates wirelessly and offers rapid and remote quantification of spermine, making it a promising material for the development of cost-effective tools for non-invasive cancer diagnosis and prognosis.

Investigating the Association Between Extended Participation in Collision Sports and Fluid Biomarkers Among Masters Athletes.

Traumatic brain injuries (TBIs) and concussions are prevalent in collision sports, and there is evidence that levels of exposure to such sports may increase the risk of neurological abnormalities. Elevated levels of fluid-based biomarkers have been observed after concussions or among athletes with a history of participating in collision sports, and certain biomarkers exhibit sensitivity toward neurodegeneration. This study investigated a cohort of 28 male amateur athletes competing in "Masters" competitions for persons >35 years of age. The primary objective of this study was to compare the levels of blood and saliva biomarkers associated with brain injury, inflammation, aging, and neurodegeneration between athletes with an extensive history of collision sport participation (i.e., median = 27 years; interquartile range = 18-44, minimum = 8) and those with no history. Plasma proteins associated with neural damage and neurodegeneration were measured using Simoa® assays, and saliva was analyzed for markers associated with inflammation and telomere length using quantitative real-time polymerase chain reaction. There were no significant differences between collision and non-collision sport athletes for plasma levels of glial fibrillary acidic protein, neurofilament light, ubiquitin C-terminal hydrolase L1, tau, tau phosphorylated at threonine 181, and brain-derived neurotrophic factor. Moreover, salivary levels of genes associated with inflammation and telomere length were similar between groups. There were no significant differences between groups in symptom frequency or severity on the Sport Concussion Assessment Tool-5th Edition. Overall, these findings provide preliminary evidence that biomarkers associated with neural tissue damage, neurodegeneration, and inflammation may not exhibit significant alterations in asymptomatic amateur athletes with an extensive history of amateur collision sport participation.

Breast milk oxytocin and s-IgA modulate infant biomarkers and social engagement; The role of maternal anxiety

Breastfeeding has long been known to improve infants' health and mental development and to enhance the mother-infant bond, but much less research focused on the biological composition of breast milk and its associations with the infant's biomarkers and social development. In this exploratory study, we measured oxytocin (OT) and secretory immunoglobulin-A (s-IgA), the most abundant antibody in breast milk, and evaluated their associations with the same biomarkers in infant saliva and, consequently, with infant social engagement behavior. Fifty-five mother-infant dyads were home-visit and OT and s-IgA were assessed from breast milk and from infant saliva before and after a free-play interaction. Infant social behavior was coded offline using the Coding Interactive Behavior (CIB) and maternal anxiety self-reported. A path model revealed that mother's breast milk s-IgA impacted child social engagement via its links with child OT. In parallel, maternal breast milk OT was linked with infant social behavior through its association with the infant's immunity. This path was moderated by maternal anxiety; only in cases of high anxiety breast milk OT was positively connected to infant s-IgA. Our study, the first to measure OT and s-IgA in both breast milk and infant saliva in relation to observed social behavior, underscores the need for much further research on the dynamic interplay between breast milk composition, infant biomarkers, maternal mental health, and infant social outcomes. Results may suggest that biological systems in breast milk integrate to prepare infants to function in their social ecology through bio-behavioral feedback loops that signal the degree of stress in the environment.

Fully Integrated Ratiometric Fluorescence Enrichment Platform for High-Sensitivity POC Testing of Salivary Cancer Biomarkers.

The point-of-care (POC) testing of cancer biomarkers in saliva with both high sensitivity and accuracy remains a serious challenge in modern clinical medicine. Herein, we develop a new fully integrated ratiometric fluorescence enrichment platform that utilizes acoustic radiation forces to enrich dual-emission sandwich immune complexes for a POC visual assay. As a result, the color signals from red and green fluorescence (capture probe and report probe, respectively) are enhanced by nearly 10 times, and colorimetric sensitivity is effectively improved. When illuminated using a portable UV lamp, the fluorescence color changing from red to green can be clearly seen with the naked eye, which allows a semiqualitative assessment of the carcinoembryonic antigen (CEA) level. In combination with a homemade smartphone-based portable device, cancer biomarkers like CEA are quantified, achieving a limit of detection as low as 0.012 ng/mL. We also directly quantify CEA in human saliva samples to investigate the reliability of this fully integrated platform, thus validating the usefulness of the proposed strategy for clinical diagnosis and home monitoring of physical conditions.

An Alternating Current Electroosmotic Flow-Based Ultrasensitive Electrochemiluminescence Microfluidic System for Ultrafast Monitoring, Detection of Proteins/miRNAsin Unprocessed Samples.

Early diagnosis of acute diseases is restricted by the sensitivity and complex process of sample treatment. Here, an ultrasensitive, rapid, and portable electrochemiluminescence-microfluidic (ECL-M) system is described via sandwich-type immunoassay and surface plasmonic resonance (SPR) assay. Using a sandwich immunoreaction approach, the ECL-M system employs cardiac troponin-I antigen (cTnI) as a detection model with a Ru@SiO2 NPs labeled antibody as the signal probe. For miR-499-5p detection, gold nanoparticles generate SPR effects to enhance Ru(bpy)3 2+ ECL signals. The system based on alternating current (AC) electroosmotic flow achieves an LOD of 2 fg mL-1 for cTnI in 5 min and 10 aM for miRNAs in 10 min at room temperature. The point-of-care testing (POCT) device demonstrated 100% sensitivity and 98% specificity for cTnI detection in 123 clinical serum samples. For miR-499-5p, it exhibited 100% sensitivity and 97% specificity in 55 clinical serum samples. Continuous monitoring of these biomarkers in rats' saliva, urine, and interstitial fluid samples for 48 hours revealed observations rarely documented in biotic fluids. The ECL-M POCT device stands as a top-performing system for ECL analysis, offering immense potential for ultrasensitive, rapid, highly accurate, and facile detection and monitoring of acute diseases in POC settings.

An attomolar-level electrochemical DNA biosensor based on target-triggered and entropy-driven catalytic amplification integrated with AuNPs@ZIF-8 nanocomposites for oral cancer overexpressed 1 detection

It is of great interest and necessity to develop a nonenzymatic, simple but highly sensitive biosensor for early diagnosis of oral cancer. Present here is an electrochemical DNA biosensor which integrates a target-triggered, entropy-driven, nonenzymatic and isothermal amplification strategy with gold nanoparticles/zeolitic imidazolate frameworks-8 (AuNPs@ZIF-8) nanocomposites for ultra-sensitive detection of oral cancer-related biomarker (ORAOV 1) in saliva. It is worth noting that the nuclease is not involved in the whole reaction process, which is simple and flexible in design only using a series of linear single-stranded DNA, avoiding undesired secondary structure interference. Meanwhile, due to the synergistic effect of AuNPs and ZIF-8, AuNPs@ZIF-8 nanocomposites display high stability, excellent electrical conductivity and exceptional electrocatalytic activity, further enhancing the electrochemical signal and avoiding labeling electrochemical signal probes. Experimental results demonstrate that this electrochemical DNA biosensor has a wide linear range (1 fM ∼1 nM), a low limit of detection (163 aM), excellent specificity, superior reproducibility and stability to ORAOV 1. More importantly, the actual application of the newly developed electrochemical biosensor is exemplified in human saliva with satisfactory recoveries. Therefore, the newly developed electrochemical biosensor has a broad application prospect in the nondestructive and early screening of oral cancer.

Femtomolar detection of the heart failure biomarker NT-proBNP in artificial saliva using an immersible liquid-gated aptasensor with reduced graphene oxide

Measuring NT-proBNP biomarker is recommended for preliminary diagnostics of the heart failure. Recent studies suggest a possibility of early screening of biomarkers in saliva for non-invasive identification of cardiac diseases at the point-of-care. However, NT-proBNP concentrations in saliva can be thousand time lower than in blood plasma, going down to pg/mL level. To reach this level, we developed a label-free aptasensor based on a liquid-gated field effect transistor using a film of reduced graphene oxide monolayer (rGO-FET) with immobilized NT-proBNP specific aptamer. We found that, depending on ionic strength of tested solutions, there were different levels of correlation in responses of electrical parameters of the rGO-FET aptasensor, namely, the Dirac point shift and transconductance change. The correlation in response to NT-proBNP was high for 1.6 mM phosphate-buffered saline (PBS) and zero for 16 mM PBS in a wide range of analyte concentrations, varied from 1 fg/mL to 10 ng/mL. The effects of transconductance and Dirac point shift in PBS solutions of different concentrations are discussed. The biosensor exhibited a high sensitivity for both transconductance (2 µS/decade) and Dirac point shift (2.3 mV/decade) in diluted PBS with the linear range from 10 fg/mL to 1 pg/mL. The aptasensor performance has been also demonstrated in undiluted artificial saliva with the achieved limit of detection down to 41 fg/mL (∼4.6 fM).

Label-Free SERS and MD Analysis of Biomarkers for Rapid Point-of-Care Sensors Detecting Head and Neck Cancer and Infections.

For the progress of point-of-care medicine, where individual health status can be easily and quickly monitored using a handheld sensor, saliva serves as one of the best-suited body fluids thanks to its availability and abundance of physiological indicators. Salivary biomarkers, combined with rapid and highly sensitive detection tools, may pave the way to new real-time health monitoring and personalized preventative therapy branches using saliva as a target matrix. Saliva is increasing in importance in liquid biopsy, a non-invasive approach that helps physicians diagnose and characterize specific diseases in patients. Here, we propose a proof-of-concept study combining the unique specificity in biomolecular recognition provided by surface-enhanced Raman spectroscopy (SERS) in combination with molecular dynamics (MD) simulations, which give leave to explore the biomolecular absorption mechanism on nanoparticle surfaces, in order to verify the traceability of two validated salivary indicators, i.e., interleukin-8 (IL-8) and lysozyme (LYZ), implicated in oropharyngeal squamous cell carcinoma (OSCC) and oral infection. This strategy simultaneously assures the detection and interpretation of protein biomarkers in saliva, ultimately opening a new route for the evolution of fast and accurate point-of-care SERS-based sensors of interest in precision medicine diagnostics.

254 Mineral Source Matters for Cartilage Development to Support Structural Integrity

Abstract Lameness is a welfare issue generally associated with increased growth rate. Objectives of this study were to 1) compare efficacy of inorganic (ITM) and organic trace mineral (OTM) sources on lameness incidence and effects on bone and cartilage biomarkers, and 2) determine if the biologically relevant biomarkers were detectable in saliva. Dietary treatments were fed for 70 d and included: 1) ITM sulfates, Zn-Cu-Mn supplemented at 120-20-40 mg/kg diet, and three OTMs supplemented at 80-10-20 Zn-Cu-Mn mg/kg diet, respectfully. The OTM treatments included a non-specific amino acid complex (Trt 2 – OTM complex), a glycinate (Trt 3 - OTM glycinate), and a metal methionine hydroxy analogue chelate (Trt 4 – OTM MMHAC) supplied as MINTREX trace minerals (Novus International, Inc., St Charles, MO). The study consisted of 144 barrows (56 kg initial BW; 36 pigs/trt; 18 pigs/pen on slatted concrete floors). A source of ractopamine hydrochloride (10 mg/kg) was fed the last 28 d of the trial to induce increased growth rate. Measurements included gait scoring (0-4; GS ≥ 2 defined as lame) and serum and saliva bone synthesis (osteocalcin), bone degradation (CTX1) and cartilage synthesis (P2CP), and cartilage degradative biomarkers (CTX2, C2C) and synthesis:degradation ratios measured at baseline, d 7, d 36 and d 70. Individual biomarkers were logarithmically transformed (base 10). Proc Mixed GLM procedure of SAS was performed on log-transformed data and means were determined using LSD test. Nonparametric comparisons (% lameness) were tested using Chi-squared analysis. A P-value &amp;lt; 0.05 was considered significant and P ≤ 0.10, a trend. As shown in Table, 1, lameness incidence was greatest for pigs fed ITM and OTM glycinate which was greater than OTM complex and MMHAC (P = 0.10). In general, there was good agreement between serum and saliva biomarkers, with pigs fed MMHAC having the greatest serum bone synthesis biomarker (osteocalcin) which differed from pigs fed OTM complex (P &amp;lt; 0.05). Cartilage synthesis concentrations (P2CP (serum and saliva); and P2CP/C2C and P2CP/CTX2 ratios (saliva) were also greatest for pigs fed MMHAC trace minerals (P &amp;lt; 0.05). Neither bone nor cartilage biomarkers were different between pigs fed ITM and OTM complex or glycinate. Osteocalcin was 10-fold less in saliva compared with serum. No treatment differences were observed in saliva for bone synthesis. The results demonstrated trace mineral source matters with respect to structural health. Significant differences between OTM sources were observed with MMHAC resulting in the highest bone and cartilage synthesis biomarker concentrations in serum and highest biomarkers for cartilage synthesis and synthesis:degradation ratios in saliva. Saliva appears to be a sensitive medium for measuring joint health biomarkers.

Connections between cross-tissue and intra-tissue biomarkers of aging biology in older adults

BackgroundSaliva measures are generally more accessible than blood, especially in vulnerable populations. However, connections between aging biology biomarkers in different body tissues remain unknown.MethodsThe present study included individuals (N = 2406) who consented for saliva and blood draw in the Health and Retirement Telomere length study in 2008 and the Venous blood study in 2016 who had complete data for both tissues. We assessed biological aging based on telomere length in saliva and DNA methylation and physiology measures in blood. DNA methylation clocks combine information from CpGs to produce the aging measures representative of epigenetic aging in humans. We analyzed DNA methylation clocks proposed by Horvath (353 CpG sites), Hannum (71 CpG sites), Levine or PhenoAge, (513 CpG sites), GrimAge, (epigenetic surrogate markers for select plasma proteins), Horvath skin and blood (391 CpG sites), Lin (99 CpG sites), Weidner (3 CpG sites), and VidalBralo (8 CpG sites). Physiology measures (referred to as phenotypic age) included albumin, creatinine, glucose, [log] C-reactive protein, lymphocyte percent, mean cell volume, red blood cell distribution width, alkaline phosphatase, and white blood cell count. The phenotypic age algorithm is based on parametrization of Gompertz proportional hazard models. Average telomere length was assayed using quantitative PCR (qPCR) by comparing the telomere sequence copy number in each patient’s sample (T) to a single-copy gene copy number (S). The resulting T/S ratio was proportional to telomere length, mean. Within individual, relationships between aging biology measures in blood and saliva and variations according to sex were assessed.ResultsSaliva-based telomere length showed inverse associations with both physiology-based and DNA methylation-based aging biology biomarkers in blood. Longer saliva-based telomere length was associated with 1 to 4 years slower biological aging based on blood-based biomarkers with the highest magnitude being Weidner (β = − 3.97, P = 0.005), GrimAge (β = − 3.33, P < 0.001), and Lin (β = − 3.45, P = 0.008) biomarkers of DNA methylation.ConclusionsThere are strong connections between aging biology biomarkers in saliva and blood in older adults. Changes in telomere length vary with changes in DNA methylation and physiology biomarkers of aging biology. We observed variations in the relationship between each body system represented by physiology biomarkers and biological aging, particularly at the DNA methylation level. These observations provide novel opportunities for integration of both blood-based and saliva-based biomarkers in clinical care of vulnerable and clinically difficult to reach populations where either or both tissues would be accessible for clinical monitoring purposes.

Influence of the circadian cycle, sex and production stage on the reference values of parameters related to stress and pathology in porcine saliva

BackgroundThe concentration of biomarkers in saliva could be influenced by several factors not related to the specific condition under analyses, which should be considered for proper clinical interpretation. In the present study, the circadian rhythm of C-reactive protein (CRP), haptoglobin (Hp), Pig-MAP, S100A12, Cu, Zn, Adenosine deaminase (ADA), total protein (TP), total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), cortisol and α-amylase in saliva of 20 female and 20 male pigs was investigated. Moreover, the influence of sex and production phase (post-weaning, fattening and finishing) on the concentrations of biomarkers in a total of 414 healthy pigs was studied and the reference intervals for all salivary biomarkers were calculated accordingly.ResultsAll parameters except Pig-MAP, OSI and α-amylase varied significantly along the daytime, and most of them peak around early afternoon (13–15 h). The cosinor analysis described the temporal dynamics of circadian rhythms for all parameters. The range values showed differences between male and female pigs in 8 out of the 13 biomarkers, with higher concentrations in females in comparison to male pigs. The influence of the production phase on the salivary concentrations was observed for all the biomarkers. The highest concentrations were observed for Pig-MAP, S100A12 and α-amylase in post-weaning animals, for TP in growing pigs and for OSI in finishing animals. Most of the sex-influenced biomarkers showed the highest concentrations at growing stages with some exceptions such as ADA or Hp that showed the peak at finishing and post-weaning stages respectively.ConclusionsIt is necessary to establish the optimal daytime for routine saliva sampling to avoid circadian variations and for that end, the time interval between 10:00 a.m. to 12:00 a.m. is highly recommended. The factors sex and production phase influence the concentration of biomarkers and should be considered for proper biomarker interpretation. The reference intervals presented here for each salivary biomarker will help to correctly interpret the results of these analytes and contribute to the use of saliva as a non-invasive sample for the diagnosis and monitoring of the health status of swine farms.

Role of Salivary Biomarkers in Oral Cancer Detection- A Systematic Review

Saliva is an informative biological fluid that has gained a lot of interest because of its physiologic diagnostic medium. The salivary secretions are under control of sympathetic and parasympathetic stimulation. It contains enzymes, proteins, biochemicals. It has been suggested to be ultrafiltrate of blood. The recent findings suggest that saliva could be used as a biomarker in diagnosing oral cancer. The study of saliva as a biological matrix has been identified as a new landmark initiative in search of a useful biomarker to diagnose oral cancer through and transcriptomes. Most oral cancers are oral squamous cell carcinoma using saliva for early oral cancer detection in the search for new clinical markers is a promising approach because of its noninvasive sampling and easy collection method. Identification of this salivary biomarker could help to screen patients at risk, predict disease outcome and effectively contribute to planning treatment strategies. Biomarkers in saliva can be used as for diagnostic &amp; response to treatment in oral squamous cell carcinoma.in this review, we explored their application in this increasingly common disease. A systematic review of the literature was performed based on the English titles listed in the PubMed, EBSCO, Cochrane, Science Direct, ISI web Science, and SciELO databases using the keywords. This article may help to identify the potential biomarkers for screening and the molecular pathology analysis in the high-risk patients with the OSCC.

A COVID19-selective pH-paper test: Ultrafast and highly accurate antibody-free viral detection in native saliva

COVID-19 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 has led to high mortality worldwide, with social and financial effects expected to persist for years to come. Since asymptomatic individuals cause a large portion of transmission, actions taken to curb the COVID-19 pandemic mostly rely on procedures aimed at detecting viral-related molecules in infected carriers. Currently, leading available detection methods fall short in reliability or point-of-care mass screening applicability.Here, we present an unprecedented antibody-free smart pH paper-based seconds-long detection platform against the virus-related enzyme 3CLpro as a saliva biomarker of SARS-CoV-2 infection. The selective proteolytic activity of 3CLpro is directly detected from native saliva using a peptide substrate-embedded pH-paper platform. 3CLpro presence in infected individuals leads to an ultrafast pH-drop in the paper matrix, thus leading to a sharp color change as direct means of detection.Ultrafast detection, simplicity, no requirement of surface chemistry by sensitive biomolecules, long-term stability, and point-of-care compatibility for COVID-19 mass screening were demonstrated. Forty-two subjects were tested, exhibiting highly sensitive and specific detection of SARS-CoV-2 infection. Finally, we foresee that this universal approach could be implemented for the multiplexed detection of other viral infections by detecting specific viral proteases.Importantly, since our approach does not require immune-specific antibodies for specific detection, the overall platform is extremely cost-efficient, less than 2 USD cents per assay, and suitable for the worldwide mass screening of viral infections, particularly in remote and developing world locations. Moreover, we propose an extremely easy-to-use and produce practical test strip design.

Effects of PM2.5 emissions from household fuel combustion on biomarkers and pulmonary function in rural areas of Fenwei Plain, China

Rural household solid fuel combustion poses serious health risks in China. This study investigated the effects of PM2.5 and its organic carbon (OC) and elemental carbon (EC) emissions from various solid fuel combustion on biomarkers (i.e., interleukin-6 [IL-6], 8-hydrox-2′-deoxyguanosine [8-OHdG], and vascular endothelial growth factor [VEGF]) in human urine (u) and saliva (s) as well as on lung function. A total of 148 villagers burned various solid fuels (i.e., clean briquette coal, raw coal chunk, and biomass) in rural areas of Fenwei Plain in China were selected. The biomass group demonstrated the highest u-IL-6, s-IL-6, and s-8-OHdG levels, which were 1.2–3.1 times those of coal groups, whereas the clean briquette coal group exhibited the highest u-8-OHdG, and u-VEGF levels. In linear regression controlled for variables, a 1 g kg−1 increase in PM2.5 emission factor (EF) resulted in a decline in u-VEGF levels by 0.553 μg mol−1 UCr and increases in s-IL-6 and s-8-OHdG levels by 0.119 and 0.545 μg mol−1 UCr, respectively. A 1 g kg−1 increase in OC EF was associated with the upregulation of s-IL-6 and s-8-OHdG levels by 0.187 and 14.421 pg mL−1, respectively, a 1 g kg−1 increase in EC EF led to an increase in s-IL-6 by 0.354 pg mL−1. No significant differences in pulmonary function were observed among the three groups, nor did PM2.5 and its OC and EC significantly affect lung function. Through noninvasive tests, this study provided evidence on the effect of PM2.5 emitted from household fuel combustion emissions on human inflammation and oxidative stress responses.

Differential expression of biomarkers in saliva related to SARS-CoV-2 infection in patients with mild, moderate and severe COVID-19

BackgroundSevere COVID-19 is a disease characterized by profound dysregulation of the innate immune system. There is a need to identify highly reliable prognostic biomarkers that can be rapidly assessed in body fluids for early identification of patients at higher risk for hospitalization and/or death. This study aimed to assess whether differential gene expression of immune response molecules and cellular enzymes, detected in saliva samples of COVID-19 patients, occurs according to disease severity staging.MethodsIn this cross-sectional study, subjects with a COVID-19 diagnosis were classified as having mild, moderate, or severe disease based on clinical features. Transcripts of genes encoding 6 biomarkers, IL-1β, IL-6, IL-10, C-reactive protein, IDO1 and ACE2, were measured by RT‒qPCR in saliva samples of patients and COVID-19-free individuals.ResultsThe gene expression levels of all 6 biomarkers in saliva were significantly increased in severe disease patients compared to mild/moderate disease patients and healthy controls. A significant strong inverse relationship between oxemia and the level of expression of the 6 biomarkers (Spearman’s correlation coefficient between -0.692 and -0.757; p < 0.001) was found.ConclusionsBiomarker gene expression determined in saliva samples still needs to be validated as a potentially valuable predictor of severe clinical outcomes early at the onset of COVID-19 symptoms.

Periodontal Status and Saliva Metabolic Signature in Patients with Alzheimer's Disease.

Characterizing the periodontal status of patients with Alzheimer's disease (AD), investigating differences in salivary metabolism between patients with and without AD under the same periodontal conditions, and understanding how it is related to oral flora are critical. We aimed to examine the periodontal condition of patients with AD and to screen salivary metabolic biomarkers from the saliva of individuals with and without AD with matched periodontal conditions. Furthermore, we aimed to explore the possible relationship between salivary metabolic changes and oral flora. In total, 79 individuals were recruited into the experiment for periodontal analysis. Especially, 30 saliva samples from the AD group and 30 from healthy controls (HCs) with matched periodontal conditions were selected for metabolomic analysis. The random-forest algorithm was used to detect candidate biomarkers. Among these, 19 AD saliva and 19 HC samples were selected to investigate the microbiological factors influencing the alterations in saliva metabolism in patients with AD. The plaque index and bleeding on probing were considerably higher in the AD group. Further, Cis-3-(1-carboxy-ethyl)-3,5-cyclohexadiene-1,2-diol, dodecanoic acid, genipic acid, and N, N-dimethylthanolamine N-oxide were determined as candidate biomarkers, based on the area under the curve (AUC) value (AUC = 0.95). The results of oral-flora sequencing showed that dysbacteriosis may be a reason for the differences in AD saliva metabolism. Dysregulation of the proportion of specific bacterial flora in saliva plays a vital role in metabolic changes in AD. These results will contribute to further improving the AD saliva biomarker system.

A colorimetric biosensor based on a biodegradable fluidic device capable of efficient saliva sampling and salivary biomarker detection

The use of saliva as a diagnostic biofluid offers many advantages over traditional blood-based diagnostics, and has the potential to revolutionize the field of point-of-care and personalized medicine. However, there remains a strong demand for precise and convenient saliva sampling and an all-in-one system that can achieve saliva sample loading and biomarker detection in a patient-friendly, easy-to-use, and cost-effective manner. In this study, we developed a biodegradable fluidic device for use in point-of-care diagnostics using saliva as a sample biofluid. The device comprised a sample loading zone and a detection zone connected through channels. A chitosan sponge was used to sample artificial saliva owing to its large absorption capacity and ability to release absorbed saliva, and polyethylene glycol-based hydrogel entrapping enzymes and dyes were used as the sensing module for the colorimetric detection of target biomarkers. When a saliva-absorbed chitosan sponge was inserted into the loading zone and squeezed, the absorbed saliva was released from the sponge and moved to the detection zone containing the hydrogel-based sensing module, where it initiated an enzyme-catalyzed reaction and subsequently induced a color change in the hydrogel. The enzyme-based detection of glucose and creatinine in a clinically useful concentration range confirmed the effectiveness of the proposed fluidic system. The proposed system enabled the quantitative detection of glucose and creatinine both spectrophotometrically and via smartphone-based analysis, highlighting its potential in point-of-care diagnostics.