title: Biodegradable and pH-responsive nanoparticles designed for site-specific delivery in agriculture.
abstract: We report the synthesis and characterization of pH-responsive polysuccinimide-based nanoparticles. Polysuccinimide (PSI), a precursor to biodegradable poly(aspartic acid), was synthesized from the condensation of l-aspartic acid and subsequently functionalized with primary amines to form random amphiphilic copolymers. The copolymers formed stable nanoparticles in aqueous medium via nanoprecipitation and were subsequently loaded with a model hydrophobic molecule to demonstrate their potential as controlled-release delivery vehicles. It was found that above pH 7, the hydrophobic succinimidyl units of the PSI nanoparticles hydrolyzed to release encapsulated materials. The release rate significantly increased at elevated pH and decreased with an increasing degree of functionalization. Finally, plant toxicity studies showed that the polymer materials exhibit little to no toxic effects at biologically relevant concentrations.
authors.forename: Megan R
authors.initials: MR
authors.lastname: Hill
authors.forename: Elliot J
authors.initials: EJ
authors.lastname: MacKrell
authors.forename: Carl P
authors.initials: CP
authors.lastname: Forsthoefel
authors.affiliation: ‡Horticultural Sciences Department, University of Florida, P.O. Box 110690, Gainesville, Florida 32611, United States.
authors.forename: Shaun P
authors.initials: SP
authors.lastname: Jensen
authors.affiliation: §Indian River Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, 2199 South Rock Road, Fort Pierce, Florida 34945, United States.
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Chen
authors.affiliation: ‡Horticultural Sciences Department, University of Florida, P.O. Box 110690, Gainesville, Florida 32611, United States.
authors.forename: Gloria A
authors.initials: GA
authors.lastname: Moore
authors.affiliation: §Indian River Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, 2199 South Rock Road, Fort Pierce, Florida 34945, United States.
authors.forename: Zhenli L
authors.initials: ZL
authors.lastname: He
authors.forename: Brent S
authors.initials: BS
authors.lastname: Sumerlin
mesh_terms: D000383:Agriculture / Q000379:methods; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism / Q000633:toxicity; D063566:Biodegradable Plastics / Q000138:chemical synthesis / Q000378:metabolism* / Q000633:toxicity; D002957:Citrus / Q000187:drug effects* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D053758:Nanoparticles / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D012639:Seeds / Q000187:drug effects / Q000378:metabolism
chemical_list: D063566:Biodegradable Plastics; D010455:Peptides; C017645:polyaspartate; C025252:poly-DL-succinimide; D001224:Aspartic Acid