Biopolymeric and lipid-based nanotechnological strategies for the design and development of novel mosquito repellent systems: recent advances

Abstract

Mosquitoes are the most medically important arthropod vectors of several human diseases. These diseases are known to severely incapacitate and debilitate millions of people, resulting in countless loss of lives. Over the years, several measures have been put in place to control the transmission of mosquito-borne diseases, one of which is using repellents. Repellents are one of the most effective personal protective measures against mosquito-borne diseases. However, conventional delivery systems of repellents (e.g., creams, gels, and sprays) are plagued with toxicity and short-term efficacy issues. The application of biopolymeric and lipid-based systems has been explored over the years to develop better delivery systems for active pharmaceutical ingredients including mosquito repellents. These delivery systems (e.g., solid lipid micro/nanoparticles, micro/nanoemulsions, or liposomes) possess desirable properties such as high biocompatibility, versatility, and controlled/sustained drug delivery, and thus are very important in tackling the clinical challenges of conventional repellent systems. Their capability for controlled/sustained drug release has improved patient compliance as it removes the need for consistent reapplication of repellents. They can also be engineered to reduce repellents' skin permeation, consequently improving their safety. However, despite the benefits that these systems offer very few of them have been successfully translated to the global market for commercial use, a vital challenge that previous reports have not thoroughly examined. The issue of limited clinical translation of novel repellent systems is a vital aspect to consider, as the ultimate goal is to move these systems from bench to bedside. As such, this study seeks to highlight the recent advances in the use of biopolymeric and lipid-based systems for the development of novel mosquito-repellent systems and also analyze the challenges that have limited the clinical translation of these systems while proposing possible strategies to overcome these challenges.

Fig. 1. Common mosquito species, diseases they transmit and general methods of mosquito control (created with BioRender).

Fig. 2. (a) Role of repellents in the prevention of disease transmission; (b) properties of an ideal repellent (created with BioRender).

Fig. 3. Process of chitosan extraction.

Fig. 4. Benefits of novel bio-polymeric and lipid-based drug delivery systems in the development of topical repellent systems (created with BioRender).

Fig. 5. Scanning electron microscopy micrographs of citronella-loaded polyurethane microcapsules (a) before and (b) after mechanical stress. Reproduced from ref. with permission from Elsevier, copyright 2016. (c) Schematic representation of the structure and drug loading processes for micro/nanocapsules (created with BioRender).

Fig. 6. Schematic representation of the structure and drug loading processes for solid lipid micro/nanoparticles (created with BioRender).

Fig. 7. Schematic representation of the structure and drug loading processes for cyclodextrins (created with BioRender).

Fig. 8. (a) Photograph of a footlet prepared from the microporous polymers. (b) Model of the microporous strand showing the liquid core location, the vapour-filled microporous region, and the outer skin layer that functions like a membrane that limits the rate at which the repellent is released. Reproduced from ref. with permission from Elsevier, copyright 2019.

Fig. 9. SEM micrographs showing the effect of insect repellent type and concentration on the structure of the internal microporous region of extruded LLDPE strands. (a) 20 wt% DEET, (b) 30 wt% DEET, (c) 20 wt% icaridin, and (d) 30 wt% icaridin. Reproduced from ref. with permission from Elsevier, copyright 2019.

Fig. 10. Images of a sample repellent sock and glove made from porous polymeric materials. Reproduced from ref. with permission from Elsevier, copyright 2018.

Chinekwu Nwagwu

Adaeze Onugwu

Frankline Kenechukwu

Clemence Tarirai

Kenneth Ofokansi

Anthony Attama