title: γ-Polyglutamic acid/chitosan nanoparticles for the plant growth regulator gibberellic acid: Characterization and evaluation of biological activity.
abstract: The growth regulator gibberellic acid (GA3) has several uses in the field, improving germination, plant development, productivity, and the quality of food. This work describes the development of a nanocarrier system for GA3, based on the poly(γ-glutamic acid) (γ-PGA) and chitosan (CS) polymers, Nanoparticles without GA3(nano-γPGA/CS-GA3) showed colloidal characteristics, with an average size of 117±9nm, PDI of 0.43±0.07, and zeta potential of -29±0.5mV. The encapsulated nanoparticles (nano-γPGA/CS-GA3) presented an average size of 134±9nm, PDI of 0.35±0.05, zeta potential of 27.9±0.5mV, and 61% encapsulation. The images of nanoparticles observed by Transmission and scanning electron microscopy (TEM and SEM) showed a spherical shape of the nanoparticles. The system showed sustained release, with 58% release after 48h. Evaluation of thermal properties using DSC and TGA analyses indicated that there was an interaction between the CS and γ-PGA polymers. In tests using Phaseolus vulgaris seeds, nano-γPGA/CS-GA3showed high biological activity, enhancing the rate of germination in the first day (50-70%) when compared with free GA3(10-16%). Encapsulated GA3was also more efficient than the free hormone in the increase of leaf area and the induction of root development (including the formation of lateral roots). These effects were not observed when seeds were treated with nano-γPGA/CS without GA3. The results demonstrated the considerable potential of nano-γPGA/CS-GA3for use in agriculture.
authors.affiliation: Department of Biochemistry, State University of Campinas (UNICAMP), Campus Universitário Zeferino Vaz, s/n, Cidade Universitária, CEP 13083-870, Campinas, São Paulo, Brazil; São Paulo State University (UNESP), Institute of Science and Technology, Sorocaba, Avenida Três de Março, 511, CEP 18087-180, Sorocaba, São Paulo, Brazil.
authors.forename: A E S
authors.initials: AES
authors.lastname: Pereira
authors.affiliation: Department of Advanced Materials, Applied Chemistry Research Center (CIQA), Blvd. Enrique Reyna Hermosillo, 140, C.P. 25250, Saltillo, Coahuilla, Mexico.
authors.forename: I E
authors.initials: IE
authors.lastname: Sandoval-Herrera
authors.affiliation: Department of Advanced Materials, Applied Chemistry Research Center (CIQA), Blvd. Enrique Reyna Hermosillo, 140, C.P. 25250, Saltillo, Coahuilla, Mexico.
authors.forename: S A
authors.initials: SA
authors.lastname: Zavala-Betancourt
authors.affiliation: Department of Animal and Plant Biology, University of Londrina, PR 445 KM 380, CEP 86057-970, Londrina, PR, Brazil.
authors.forename: H C
authors.initials: HC
authors.lastname: Oliveira
authors.affiliation: Department of Advanced Materials, Applied Chemistry Research Center (CIQA), Blvd. Enrique Reyna Hermosillo, 140, C.P. 25250, Saltillo, Coahuilla, Mexico.
authors.forename: A S
authors.initials: AS
authors.lastname: Ledezma-Pérez
authors.affiliation: Department of Advanced Materials, Applied Chemistry Research Center (CIQA), Blvd. Enrique Reyna Hermosillo, 140, C.P. 25250, Saltillo, Coahuilla, Mexico. Electronic address: Jorge.romero@ciqa.edu.
authors.forename: J
authors.initials: J
authors.lastname: Romero
authors.affiliation: Department of Biochemistry, State University of Campinas (UNICAMP), Campus Universitário Zeferino Vaz, s/n, Cidade Universitária, CEP 13083-870, Campinas, São Paulo, Brazil; São Paulo State University (UNESP), Institute of Science and Technology, Sorocaba, Avenida Três de Março, 511, CEP 18087-180, Sorocaba, São Paulo, Brazil. Electronic address: leonardo@sorocaba.unesp.br.
authors.forename: L F
authors.initials: LF
authors.lastname: Fraceto
mesh_terms: D048271:Chitosan; D004337:Drug Carriers; D018525:Germination / Q000187:drug effects; D005875:Gibberellins / Q000008:administration & dosage*; D053758:Nanoparticles; D027805:Phaseolus / Q000187:drug effects; D010937:Plant Growth Regulators / Q000494:pharmacology*; D011099:Polyglutamic Acid; D012639:Seeds / Q000187:drug effects
chemical_list: D004337:Drug Carriers; D005875:Gibberellins; D010937:Plant Growth Regulators; D011099:Polyglutamic Acid; D048271:Chitosan; C007842:gibberellic acid
keywords: Agriculture; Chitosan; Gibberellic acid; Nanoparticles; Release system; γ-Polyglutamic acid