The role of grass volatiles on oviposition site selection by Anopheles arabiensis and Anopheles coluzzii

Background: The reproductive success and population dynamics, of Anopheles malaria mosquitoes is strongly influenced by the oviposition site selection of gravid females. Mosquitoes select oviposition sites at different spatial scales, starting with selecting a habitat in which to search. This study utilizes the association of larval abundance in the field with natural breeding habitats, dominated by various types of wild grasses, as a proxy for oviposition site selection by gravid mosquitoes. Moreover, the role of olfactory cues emanating from these habitats in the attraction and oviposition stimulation of females was analysed. Methods: The density of Anopheles larvae in breeding sites associated with Echinochloa pyramidalis, Echinochloa stagnina, Typha latifolia and Cyperus papyrus, was sampled and the larvae identified to species level. Headspace volatile extracts of the grasses were collected and used to assess behavioural attraction and oviposition stimulation of gravid Anopheles arabiensis and Anopheles coluzzii mosquitoes in wind tunnel and two-choice oviposition assays, respectively. The ability of the mosquitoes to differentiate among the grass volatile extracts was tested in multi-choice tent assays. Results: Anopheles arabiensis larvae were the most abundant species found in the various grass-associated habitats. The larval densities described a hierarchical distribution, with Poaceae (Echinochloa pyramidalis and Echinochloa stagnina)-associated habitat sites demonstrating higher densities than that of Typha-associated sites, and where larvae were absent from Cyperus-associated sites. This hierarchy was maintained by gravid An. arabiensis and An. coluzzii mosquitoes in attraction, oviposition and multi-choice assays to grass volatile extracts. Conclusions: The demonstrated hierarchical preference of gravid An. coluzzii and An. arabiensis for grass volatiles indicates that vegetation cues associated with larval habitats are instrumental in the oviposition site choice of the malaria mosquitoes. Identifying volatile cues from grasses that modulate gravid malaria mosquito behaviours has distinct potential for the development of tools to be used in future monitoring and control methods

The Role of Natural-Based Biomaterials in Advanced Therapies for Autoimmune Diseases

Autoimmune diseases (ADs) constitute a heterogeneous group of more than 100 pathophysiological conditions in which an immune response against the self is observed. The incidence and prevalence of these chronic diseases are increasing with inherently high social and economic impacts. The currently available therapies generally focus on reducing the activity of the immune system and, therefore, can present severe side effects such as enhanced patient susceptibility to opportunistic infections. Advanced therapies emerged as promising treatments and with real curative potential for ADs. Additionally, the use of natural polymers to engineer gene therapies, cell therapies and/or tissue-engineered medicinal products presents specific advantages. Natural polymers present higher affinity with biological systems than synthetic polymers, and frequently have a chemical structure and motifs similar to those existing in the extracellular matrix of the tissues. They also have good biological performance, making them very strong candidates for advanced therapy medicinal products. This review discusses the therapeutic advances and provides demonstrative examples of the role of natural-based biomaterials for the development of advanced therapies for ADs.Programa Operacional Norte 2020 under the research project FROnTHERA (NORTE-01-0145-FEDER-000023) and the Fundação para a Ciência e Tecnologia do Ministério da Ciência e Tecnologia (FCT, Portugal) under the research project SPARTAN (PTDC/CTM-BIO/4388/2014)info:eu-repo/semantics/publishedVersio