Recent advances of biosensors for hypertension and nephrology

Electrochemical biosensor based on RNA aptamer and ferrocenecarboxylic acid signal probe for C-reactive protein detection

Monitoring health-related biomarkers using fast and facile detection techniques provides key physicochemical information for disease diagnosis or reflects body health status. Among them, electrochemical detection of various bio-macromolecules, e.g., the C-reactive protein (CRP), is of great interest in offering potential diagnosis for acute inflammation caused by infections, heart diseases, etc. Herein, a novel electrochemical aptamer biosensor was constructed from Ti3C2Tx MXene and in-situ reduced Au NPs for thiolated-RNA aptamer immobilization and CRP protein detection using Fc(COOH) as the signal probe. The sensory performances for CRP detection were optimized based on working conditions, including the incubation times and the pH. The large surface area offered by Ti3C2Tx MXene and high electrical conductivity originating from Au NPs endowed the as-fabricated aptamer biosensor with a decent sensitivity for CRP in a wide linear range of 0.05-80.0 ng/mL, good selectivity over interfering substances, and a low detection limit of 0.026 ng/mL. Such aptamer biosensors also detected CRP in serum samples using the spike & recovery method with reasonable recovery rates. The results demonstrated the potential of the as-fabricated electrochemical aptamer biosensor for fast and facile CRP detection in practical applications.

Advances in the Treatment Strategies in Hypertension: Present and Future

Hypertension is the most frequent chronic and non-communicable disease all over the world, with about 1.5 billion affected individuals worldwide. Its impact is currently growing, particularly in low-income countries. Even in high-income countries, hypertension remains largely underdiagnosed and undertreated, with consequent low rates of blood pressure (BP) control. Notwithstanding the large number of clinical observational studies and randomized trials over the past four decades, it is sad to note that in the last few years there has been an impressive paucity of innovative studies. Research focused on BP mechanisms and novel antihypertensive drugs is slowing dramatically. The present review discusses some advances in the management of hypertensive patients, and could play a clinical role in the years to come. First, digital/health technology is expected to be increasingly used, although some crucial points remain (development of non-intrusive and clinically validated devices for ambulatory BP measurement, robust storing systems enabling rapid analysis of accrued data, physician-patient interactions, etc.). Second, several areas should be better outlined with regard to BP diagnosis and treatment targets. Third, from a therapeutic standpoint, existing antihypertensive drugs, which are generally effective and well tolerated, should be better used by exploiting available and novel free and fixed combinations. In particular, spironolactone and other mineral-corticoid receptor antagonists should be used more frequently to improve BP control. In particular, some drugs initially developed for conditions different from hypertension including heart failure and diabetes have demonstrated to lower BP significantly and should therefore be considered. Finally, renal artery denervation is another procedure that has proven effective in the management of hypertension.

Point-of-care testing technologies for the home in chronic kidney disease: a narrative review

Point-of-care testing (POCT) performed by the patient at home, paired with eHealth technologies, offers a wealth of opportunities to develop individualized, empowering clinical pathways. The non-dialysis-dependent chronic kidney disease (CKD) patient who is at risk of or may already be suffering from a number of the associated complications of CKD represents an ideal patient group for the development of such initiatives. The current coronavirus disease 2019 pandemic and drive towards shielding vulnerable individuals have further highlighted the need for home testing pathways. In this narrative review we outline the evidence supporting remote patient management and the various technologies in use in the POCT setting. We then review the devices currently available for use in the home by patients in five key areas of renal medicine: anaemia, biochemical, blood pressure (BP), anticoagulation and diabetes monitoring. Currently there are few devices and little evidence to support the use of home POCT in CKD. While home testing in BP, anticoagulation and diabetes monitoring is relatively well developed, the fields of anaemia and biochemical POCT are still in their infancy. However, patients' attitudes towards eHealth and home POCT are consistently positive and physicians also find this care highly acceptable. The regulatory and translational challenges involved in the development of new home-based care pathways are significant. Pragmatic and adaptable trials of a hybrid effectiveness-implementation design, as well as continued technological POCT device advancement, are required to deliver these innovative new pathways that our patients desire and deserve.

Fabrication of electrochemical biosensor composed of multi-functional DNA 4 way junction for TNF-α detection in human serum

Tumor necrosis factor (TNF-α) is a representative cytokine family known to induce multiple signaling cascades leading to various cellular responses, such as cell death, survival, and differentiation. It has been reported that blocking the action of TNF-α in various diseases can improve disease prognosis. Therefore, it is important to monitor TNF-α in patient plasma and properly regulate its action. In this study, we report a label-free electrochemical biosensor consisting of a multifunctional DNA 4-way junction (MF-4WJ) for TNF-α detection in human serum. MF-4WJ does not require additional labeling and signal amplification processes. The electrochemical properties of functionalized MF-4WJ were evaluated by cyclic voltammetry (CV) in the presence of Ag⁺ intercalated between the mismatched sequences of MF-aptamers as redox-active species. Afterward, CV was carried out to evaluate the performance of the fabricated biosensor. The proposed label-free electrochemical biosensor was able to effectively detect TNF-α in a dynamic range of 0.15 pg/ml to 150 ng/ml. Limit of detection (LOD) was at 0.07 pg/ml in HEPES. Moreover, it was confirmed that even in 10% diluted human serum, TNF-α could be detected in an excellent dynamic range of 0.15 pg/ml to ∼ 15 ng/ml and LOD was at 0.14 pg/ml in 10% diluted human serum.

Recent Advances in CRP Biosensor Based on Electrical, Electrochemical and Optical Methods

C-reactive protein (CRP) is an acute-phase reactive protein that appears in the bloodstream in response to inflammatory cytokines such as interleukin-6 produced by adipocytes and macrophages during the acute phase of the inflammatory/infectious process. CRP measurement is widely used as a representative acute and chronic inflammatory disease marker. With the development of diagnostic techniques measuring CRP more precisely than before, CRP is being used not only as a traditional biomarker but also as a biomarker for various diseases. The existing commercialized CRP assays are dominated by enzyme-linked immunosorbent assay (ELISA). ELISA has high selectivity and sensitivity, but its limitations include requiring complex analytic processes, long analysis times, and professional manpower. To overcome these problems, nanobiotechnology is able to provide alternative diagnostic tools. By introducing the nanobio hybrid material to the CRP biosensors, CRP can be measured more quickly and accurately, and highly sensitive biosensors can be used as portable devices. In this review, we discuss the recent advancements in electrochemical, electricity, and spectroscopy-based CRP biosensors composed of biomaterial and nanomaterial hybrids.

Fabrication of an electrochemical biosensor composed of multi-functional Ag ion intercalated DNA four-way junctions/rhodium nanoplate heterolayer on a micro-gap for C-reactive protein detection in human serum

As inflammation plays a role in the pathogenesis of acute coronary syndromes, C-reactive protein (CRP) can be used as a biomarker. To detect CRP precisely, the authors prepared a CRP electrochemical biosensor consisting of an eight Ag ion-intercalated multifunctional DNA four-way junction (MF-DNA-4WJ) and a porous rhodium nanoparticle (pRhNP) heterolayer on a micro-gap electrode. To increase conductivity, we used eight Ag⁺ ion-inserted DNA four-way junctions through a C-C mismatch. Each DNA 4WJ was designed to have the CRP aptamer sequence, an anchoring region (thiol group), and two of four C-C mismatch regions at the end of the fragments. After an annealing step, the MF-DNA-4WJ assembly configuration and selective binding of CRP were confirmed through native TBM-PAGE (Tris-borate-magnesium chloride-polyacrylamide gel electrophoresis). The Au micro-gap electrode was fabricated to load 5 μl of the sample, and this was performed during eight experiments on one chip to establish the accuracy of the data. Then, pRhNPs were immobilized on a Au micro-gap electrode using cysteamine. To confirm the electrochemical properties, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were conducted. The durability of pRhNPs was confirmed through CV. To test the sensing performance of the prepared CRP biosensor, the limit of detection (LOD) and selectivity tests were conducted using EIS. The results indicated that charge transfer resistance (R_ct) can be used efficiently to probe these interactions within the variable CRP concentration range, from 1 pM to 100 nM (0.23 ng L^-1-23 μg L^-1). The LOD of this sensor was 0.349 pM (0.08 ng L^-1) (at S/N = 3). As a result of diluting the CRP to the same concentration range in a 20% human serum sample, the LOD was 3.55 fM (0.814 pg L^-1) (at S/N = 3).

Recent advances in managing primary hypertension

Hypertension remains a leading risk factor for cardiovascular mortality and morbidity globally despite the availability of effective and well-tolerated antihypertensive medications. Accumulating evidence suggests a more aggressive blood pressure regulation aimed at lower targets, particularly for selected patient groups. Our concepts of the optimal method for blood pressure measurement have radically changed, maintaining appropriate standard office measurements for initial assessment but relying on out-of-office measurement to better guide our decisions. Thorough risk stratification provides guidance in decision making; however, an individualized approach is highly recommended to prevent overtreatment. Undertreatment, on the other hand, remains a major concern and is mainly attributed to poor adherence and resistant or difficult-to-control forms of the disease. This review aims to present modern perspectives, novel treatment options, including innovative technological applications and developing interventional and pharmaceutical therapies, and the major concerns emerging from several years of research and epidemiological observations related to hypertension management.

eHealth in kidney care

eHealth is gaining momentum in nephrology, although evidence for its efficacy remains unclear and challenges to its widespread adoption persist. Successful integration of eHealth into kidney care will require patient engagement to develop effective interventions and issues such as data validity, regulation, oversight and adequate infrastructure to be addressed.