engleski

New microcapsule formulations with plant growth promoters - Encapsulation of Amines for Sustained Release

Encapsulation of bioactive agents has been significantly developed in the last decade as a new method for ecological and sustainable plant production. One of the most important reasons for bioactive substances encapsulation is their delivery to the plants during the entire maturation period. Alginate and chitosan are recognized as safe and effective biomaterials for bioactive agents encapsulation. In this work, plant promoters based on the primary and secondary amines were synthesized and encapsulated in calcium alginate microparticles prepared by ionic gelation (microspheres) or ionic gelation and polyelectrolyte complexation with chitosan (microcapsules). Amines are compounds rich in nitrogen which can affect eutrophication processes within the ecosystem, resulting in increased availability of plant nutrients and increased plant growth. Information about intermolecular interactions between biopolymers and plant promoters by FTIR spectroscopy revealed functional groups of all components interact with each other including mainly electrostatic interactions and hydrogen bonds. Physico-chemical characterization (morphology, loading capacity, swelling) of novel microparticle formulations and release profiles of plant promoters was performed. In vitro plant promoters release study pointed out the release profiles strongly depend on plant promoters reactivity, hydrophilicity and hydrophobicity. Cpd1 was loaded in microspheres, whereas due to expressed burst effect, Cpd3 and Cpd5 had to be loaded in microcapsules (the presence of chitosan surface layer diminished bursting). Fitting to Korsmeyer–Peppas empirical model revealed the differences in microparticle surface properties and structure did not affect the mechanism controlling plant promoters release detected as diffusion through microparticles. A better understanding of the structure/property relationship in microparticle formulations and mechanisms controlling plant promoters release enhances the ability to control the release behavior and may aid in developing microparticles with specifically tailored properties.

Encapsulation ; bioactive agents ; amines

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