The paramagnetic properties of malaria pigment, hemozoin, yield clues to a low-cost system for its trapping and determination

• Published in: Talanta (Oxford) Vol. 197; pp. 553 - 557
• Main Authors: Roch, A., Prodéo, J., Pierart, C., Muller, R.N., Duez, P.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.05.2019
• Subjects: Hemozoin; Magnetic trapping; Malaria; Plasmodium falciparum; β-hematin; Plasmodium falciparum; β-hematin; Malaria; Magnetic trapping; Hemozoin
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2019.01.090

The binding of malaria pigment, hemozoin, by a gradient magnetic field has been investigated in a manual trapping column system. Two types of magnetic filling have been tested to produce field gradients: nickel-plated steel wires, wrapped around a steel core, and superparamagnetic microbeads. The latter system allows an efficient trapping (> 80%) of β-hematin (a synthetic pigment with physical and paramagnetic properties analogous to those of hemozoin). Tests with a Plasmodium falciparum 3D7 culture indicate that hemozoin is similarly trapped. Off-line optical spectroscopy measurements present limited sensitivity as the hemozoin we detected from in vitro cultured parasites would correspond to only a theoretical 0.02% parasitemia (1000 parasites/µL). Further work needs to be undertaken to reduce this threshold to a practical detectability level. Based on these data, a magneto-chromatographic on-line system with reduced dead volumes is proposed as a possible low-cost instrument to be tested as a malaria diagnosis system. [Display omitted] •Synthetic hemozoin (β-hematin) and hemozoin can be trapped on magnetized wires and microbeads.•Trapping is effective for hemozoin produced by Plasmodium falciparum in vitro cultures.•Trapped β-hematin and hemozoin can be eluted from the magnetic trap upon dissolution in alkaline solutions.•Eluted hemozoin can be spectrophotometrically measured and correlates with parasites levels.