A Lab-On-chip Tool for Rapid, Quantitative, and Stage-selective Diagnosis of Malaria

Malaria: biochemical, physiological, diagnostic, and therapeutic updates

Background

Malaria has been appraised as a significant vector-borne parasitic disease with grave morbidity and high-rate mortality. Several challenges have been confronting the efficient diagnosis and treatment of malaria.

Method

Google Scholar, PubMed, Web of Science, and the Egyptian Knowledge Bank (EKB) were all used to gather articles.

Results

Diverse biochemical and physiological indices can mirror complicated malaria e.g., hypoglycemia, dyslipidemia, elevated renal and hepatic functions in addition to the lower antioxidant capacity that does not only destroy the parasite but also induces endothelial damage. Multiple trials have been conducted to improve recent points of care in malaria involving biosensors, lap on-chip, and microdevices technology. Regarding recent therapeutic trials, chemical falcipain inhibitors and plant extracts with anti-plasmodial activities are presented. Moreover, antimalaria nano-medicine and the emergence of nanocarrier (either active or passive) in drug transportation are promising. The combination therapeutic trials e.g., amodiaquine + artemether + lumefantrine are presented to safely counterbalance the emerging drug resistance in addition to the Tafenoquine as a new anti-relapse therapy.

Conclusion

Recognizing the pathophysiology indices potentiate diagnosis of malaria. The new points of care can smartly manipulate the biochemical and hematological alterations for a more sensitive and specific diagnosis of malaria. Nano-medicine appeared promising. Chemical and plant extracts remain points of research.

Malaria therapeutics: are we close enough?

Malaria is a vector-borne parasitic disease caused by the apicomplexan protozoan parasite Plasmodium. Malaria is a significant health problem and the leading cause of socioeconomic losses in developing countries. WHO approved several antimalarials in the last 2 decades, but the growing resistance against the available drugs has worsened the scenario. Drug resistance and diversity among Plasmodium strains hinder the path of eradicating malaria leading to the use of new technologies and strategies to develop effective vaccines and drugs. A timely and accurate diagnosis is crucial for any disease, including malaria. The available diagnostic methods for malaria include microscopy, RDT, PCR, and non-invasive diagnosis. Recently, there have been several developments in detecting malaria, with improvements leading to achieving an accurate, quick, cost-effective, and non-invasive diagnostic tool for malaria. Several vaccine candidates with new methods and antigens are under investigation and moving forward to be considered for clinical trials. This article concisely reviews basic malaria biology, the parasite's life cycle, approved drugs, vaccine candidates, and available diagnostic approaches. It emphasizes new avenues of therapeutics for malaria.

Impedance-Based Rapid Diagnostic Tool for Single Malaria Parasite Detection

This paper presents a custom, low-cost electronic system specifically designed for rapid and quantitative detection of the malaria parasite in a blood sample. The system exploits the paramagnetic properties of malaria-infected red blood cells (iRBCs) for their magnetophoretic capture on the surface of a silicon chip. A lattice of nickel magnetic micro-concentrators embedded in a silicon substrate concentrates the iRBCs above coplanar gold microelectrodes separated by 3 μm for their detection through an impedance measurement. The sensor is designed for a differential operation to remove the large contribution given by the blood sample. The electronic readout automatically balances the sensor before each experiment and reaches a resolution of 15 ppm in the impedance measurement at 1 MHz allowing a limit of detection of 40 parasite/μl with a capture time of 10 minutes. For better reliability of the results, four sensors are acquired during the same experiment. We demonstrate that the realized platform can also detect a single infected cell in real experimental conditions, measuring human blood infected by Plasmodium falciparum malaria specie.

Numerical simulation of optical refractometric sensing of multiple disease markers based on lab-in-a-fiber

A multi-parameter optical refractometric sensor based on lab-in-a-fiber is proposed and its sensing properties have been investigated. Based on the particular three suspended-core fiber, the sensor has three channels for liquid circulation and three suspended cores for detection. The multiple disease markers can be detected by coating the specific bio-recognition layer on the surface of three channels. The bio-recognition layer thickness, representing the concentration of the disease markers, can then be measured by the wavelength of fiber Bragg grating inscribed in each suspended core. Owing to the triple symmetry of the fiber, the sensitivity of each core is similar. The simulation results show that the grating wavelength linearly changes with the bio-recognition layer thickness variation. Through the sensitivity matrix, the sensitivity of the sensor is 0.362 nm/nm and the sensing accuracy is ± 1 nm.

On-chip magnetophoretic capture in a model of malaria-infected red blood cells

The search for new rapid diagnostic tests for malaria is a priority for developing an efficient strategy to fight this endemic disease, which affects more than 3 billion people worldwide. In this paper, we characterize systematically an easy-to-operate lab-on-chip, designed for the magnetophoretic capture of malaria-infected red blood cells. The method relies on the positive magnetic susceptibility of infected red blood cells with respect to blood plasma. A matrix of nickel posts fabricated in a silicon chip placed face down is aimed at attracting infected cells, while healthy cells sediment on a glass slide under the action of gravity. Using a model of infected red blood cells, i.e. erythrocytes with methaemoglobin, we obtained a capture efficiency of about 70% after 10 minutes in static conditions. By proper agitation, the capture efficiency reached 85% after just 5 minutes. Sample preparation requires only a 1:10 volume dilution of whole blood, previously treated with heparin, in a phosphate buffered solution. Nonspecific attraction of untreated red blood cells was not observed in the same time interval. This article is protected by copyright. All rights reserved.