Microwaves can kill malaria parasites non-thermally.

Malaria, which infected more than 240 million people and killed around six hundred thousand only in 2021, has reclaimed territory after the SARS-CoV-2 pandemic. Together with parasite resistance and a not-yet-optimal vaccine, the need for new approaches has become critical. While earlier, limited, studies have suggested that malaria parasites are affected by electromagnetic energy, the outcomes of this affectation vary and there has not been a study that looks into the mechanism of action behind these responses. In this study, through development and implementation of custom applicators for in vitro experimentation, conditions were generated in which microwave energy (MW) killed more than 90% of the parasites, not by a thermal effect but via a MW energy-induced programmed cell death that does not seem to affect mammalian cell lines. Transmission electron microscopy points to the involvement of the haemozoin-containing food vacuole, which becomes destroyed; while several other experimental approaches demonstrate the involvement of calcium signaling pathways in the resulting effects of exposure to MW. Furthermore, parasites were protected from the effects of MW by calcium channel blockers calmodulin and phosphoinositol. The findings presented here offer a molecular insight into the elusive interactions of oscillating electromagnetic fields with P. falciparum, prove that they are not related to temperature, and present an alternative technology to combat this devastating disease.

Focused apodized forked grating coupler.

The forked grating coupler (FGC) is an optical vortex interface for silicon photonics. Using the structure of a Bragg grating coupler with a calculated forked hologram, the FGC couples optical vortex modes into confined waveguide modes of a photonic integrated circuit. Design methodologies are given, as well as measured performance data from fabricated devices. Data are analyzed with a variety of metrics. The effectiveness of design features are evaluated. Advanced FGC designs are demonstrated with focused forked gratings, allowing feed length to be reduced, and with apodization improving vortex mode fidelity. Some configurations achieve over 25 dB multiplexing crosstalk isolation.

Malarial hemozoin: from target to tool.

BACKGROUND: Malaria is an extremely devastating disease that continues to affect millions of people each year. A distinctive attribute of malaria infected red blood cells is the presence of malarial pigment or the so-called hemozoin. Hemozoin is a biocrystal synthesized by Plasmodium and other blood-feeding parasites to avoid the toxicity of free heme derived from the digestion of hemoglobin during invasion of the erythrocytes. SCOPE OF REVIEW: Hemozoin is involved in several aspects of the pathology of the disease as well as in important processes such as the immunogenicity elicited. It is known that the once best antimalarial drug, chloroquine, exerted its effect through interference with the process of hemozoin formation. In the present review we explore what is known about hemozoin, from hemoglobin digestion, to its final structural analysis, to its physicochemical properties, its role in the disease and notions of the possible mechanisms that could kill the parasite by disrupting the synthesis or integrity of this remarkable crystal. MAJOR CONCLUSIONS: The importance and peculiarities of this biocrystal have given researchers a cause to consider it as a target for new antimalarials and to use it through unconventional approaches for diagnostics and therapeutics against the disease. GENERAL SIGNIFICANCE: Hemozoin plays an essential role in the biology of malarial disease. Innovative ideas could use all the existing data on the unique chemical and biophysical properties of this macromolecule to come up with new ways of combating malaria.