Bicomponent fibres for controlled release of volatile mosquito repellents

Mthokozisi Sibanda; Walter Focke; Leo Braack; Andreas Leuteritz; Harald Brünig; Nguyen Hoai An Tran; Florian Wieczorek; Wolfgang Trümper

doi:10.1016/j.msec.2018.06.016

Bicomponent fibres for controlled release of volatile mosquito repellents

Mater Sci Eng C Mater Biol Appl. 2018 Oct 1:91:754-761. doi: 10.1016/j.msec.2018.06.016. Epub 2018 Jun 15.

Authors

Mthokozisi Sibanda¹, Walter Focke², Leo Braack³, Andreas Leuteritz⁴, Harald Brünig⁴, Nguyen Hoai An Tran⁵, Florian Wieczorek⁶, Wolfgang Trümper⁶

Affiliations

¹ University of Pretoria Institute for Sustainable Malaria Control and MRC Collaborating Centre for malaria research, University of Pretoria, Private Bag X323, Pretoria 0001, South Africa; Institute of Applied Materials, Department of Chemical Engineering, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa.
² University of Pretoria Institute for Sustainable Malaria Control and MRC Collaborating Centre for malaria research, University of Pretoria, Private Bag X323, Pretoria 0001, South Africa; Institute of Applied Materials, Department of Chemical Engineering, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa. Electronic address: walter.focke@up.ac.za.
³ University of Pretoria Institute for Sustainable Malaria Control and MRC Collaborating Centre for malaria research, University of Pretoria, Private Bag X323, Pretoria 0001, South Africa.
⁴ Leibniz Institute of Polymer Research Dresden (IPF), Hohe Straße 6, 01069 Dresden, Germany.
⁵ Leibniz Institute of Polymer Research Dresden (IPF), Hohe Straße 6, 01069 Dresden, Germany; Technische Universität Dresden, Fakultät Maschinenwesen, Institut für Textilmaschinen und Textile Hochleistungswerkstofftechnik (ITM), 01062 Dresden, Germany.
⁶ Technische Universität Dresden, Fakultät Maschinenwesen, Institut für Textilmaschinen und Textile Hochleistungswerkstofftechnik (ITM), 01062 Dresden, Germany.

PMID: 30033310
DOI: 10.1016/j.msec.2018.06.016

Abstract

Core-sheath structured fibres were developed for application as part of an alternative malaria vector control intervention aimed at reducing outdoor malaria transmission. The fibres were prepared by melt spinning of high density polyethylene (HDPE) as sheath and with a concentrate containing volatile N,N-Diethyl-m-toluamide (DEET) in poly(ethylene-co-vinyl acetate) (EVA) as core. The concentrate was prepared by a simple absorption processes to a content up to 40 wt% DEET. Scanning electron microscope imaging confirmed the formation of a bicomponent core-sheath fibre structure. Confocal Raman spectroscopy revealed the development of a concentration gradient of DEET in the sheath layer, suggesting a diffusion controlled release process. Excellent processability was demonstrated on an extrusion system melt spinning with take up speeds reaching 3000 m min^-1. Sample textiles knitted from such filaments showed high residual repellence activity even after 20 cold washes or after eight months ageing under laboratory conditions. These findings indicate that this technology offers an alternative way to prevent outdoor mosquito bites in an effective and affordable manner.

Keywords: Bicomponent fibre; Controlled release; Malaria; Mosquitoes; Repellent.

MeSH terms

Animals
Culicidae / drug effects*
DEET / toxicity*
Delayed-Action Preparations
Female
Imaging, Three-Dimensional
Insect Repellents / toxicity*
Polyethylene / chemistry*
Spectrum Analysis, Raman
Stress, Mechanical
Textiles
Thermogravimetry
Volatilization

Substances

Delayed-Action Preparations
Insect Repellents
DEET
Polyethylene