title: Novel control methods for insect pests: development of a microencapsulation procedure for proteinaceous bioactives intended for oral delivery.
abstract: BACKGROUND
  The objective was to develop an environmentally favourable microcapsule suitable for delivery of proteinaceous bioactive agents ('bioinsecticides') to pest insects.
  
  
  RESULTS
  Utilising feeding bioassays, we determined that microspheres made of alginate can be produced in a variety of sizes and are palatable and non-toxic to larvae of the lepidopteran pest Lacanobia oleracea. Dehydrated microspheres were also readily ingested by larvae. Using a novel feeding bioassay and alginate microspheres containing a fluorescent marker material (coumarin 7 encapsulated in styrene maleic anhydride beads), we determined that the microspheres successfully deliver the marker to the insect gut. Moreover, the alginate microspheres rapidly break down in the alkaline conditions of the insect gut and release their contents, the beads passing through the gut in 2-3 h. Using bovine serum albumin as a test protein and western blotting, it was determined that alginate can successfully encapsulate protein, and that the microspheres can be stored in a CaCl2 solution for up to 24 days without extensive leakage. Importantly, it was also determined that alginate and the microsphere-making procedure developed do not inactivate rVPr1 (an insect immunosuppressive protein and potential bioinsecticide).
  
  
  CONCLUSIONS
  An alginate-based microsphere has potential to deliver the proteinaceous bioactive rVPr1 to pest insects.
authors.affiliation: Plant Protection Programme, Food and Environment Research Agency, Sand Hutton, York, UK.
authors.forename: Elaine H
authors.identifier: http://orcid.org/0000-0003-0128-9611
authors.initials: EH
authors.lastname: Richards
authors.affiliation: Food Quality and Safety Programme, Food and Environment Research Agency, Sand Hutton, York, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Wontner-Smith
authors.affiliation: Plant Protection Programme, Food and Environment Research Agency, Sand Hutton, York, UK.
authors.forename: Hannah
authors.initials: H
authors.lastname: Bradish
authors.affiliation: Plant Protection Programme, Food and Environment Research Agency, Sand Hutton, York, UK.
authors.forename: M Paulina
authors.initials: MP
authors.lastname: Dani
authors.affiliation: Food Quality and Safety Programme, Food and Environment Research Agency, Sand Hutton, York, UK.
authors.forename: Jane V
authors.initials: JV
authors.lastname: Cotterill
mesh_terms: D000464:Alginates / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D019476:Insect Proteins / Q000737:chemistry*; D007814:Larva / Q000502:physiology; D008863:Microspheres; D009036:Moths / Q000502:physiology*; D010571:Pest Control / Q000379:methods; D055550:Protein Stability; D011994:Recombinant Proteins / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D019476:Insect Proteins; D011994:Recombinant Proteins; D012710:Serum Albumin, Bovine; D020723:Glucuronic Acid
keywords: alginate; bioactive; biological control; insect pest; microencapsulation; rVPr1