Microspheres of chitosan for controlled delivery of brassinosteroids with biological activity as agrochemicals

Quiñones, Javier Pérez; García, Yamilet Coll; Curiel, Harold; Covas, Carlos Peniche

doi:10.1016/j.carbpol.2010.01.006

Cited by 56 publications

(35 citation statements)

References 25 publications

(4 reference statements)

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“…The mean values for CS1 microspheres varied from 250 to 790 um, while for CS2 microspheres they ranged from 40 to 280 um. These microsphere sizes are consistent with those reported in other studies [16], but smaller than the observed in diosgenin-and brassinosteroid-loaded CS microspheres [14]. CS2 microspheres containing MID and MMD showed bimodal size distributions.…”

Section: Characterization Of Diosgenin-modified Cs Microspheressupporting

confidence: 82%

“…Differential scanning calorimetry (DSC) studies were conducted using sample weights of ca. 8 mg, under nitrogen dynamic flow of 20.0 mL min -1 and a heating-cooling rate of 10 ºC min -1 [14]. Samples were deposited in aluminum pans and hermetically sealed.…”

Section: Characterizationmentioning

confidence: 99%

“…Chitosan microspheres (CS1) were obtained by simple coacervation-precipitation and crosslinking with sodium tripolyphosphate [14]. Briefly, a 2% (wt-%) CS solution in 2% (v/v) aqueous acetic acid was added dropwise to a 10% (w/v) NaOH in methanol.…”

Section: Cs Microspheres Preparationmentioning

confidence: 99%

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Hydrophobically-modified Chitosan Microspheres for Release of Diosgenin

Quiñones¹,

Brüggemann²,

Covas³

2018

IJRN

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Section: Characterization Of Diosgenin-modified Cs Microspheressupporting

confidence: 82%

Section: Characterizationmentioning

confidence: 99%

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Hydrophobically-modified Chitosan Microspheres for Release of Diosgenin

Quiñones¹,

Brüggemann²,

Covas³

2018

IJRN

Self Cite

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“…Moreover, very few studies have considered the use of chitosan-derived systems for the controlled delivery of agrochemicals. Some notable examples include the delivery of neem seed oil (Devi and Maji, 2009), plant hormones (Quiñones et al, 2010;Fan et al, 2012) and fertilisers and herbicide (Teixeira et al, 1990).…”

Section: Introductionmentioning

confidence: 99%

Slow delivery of a nitrification inhibitor (dicyandiamide) to soil using a biodegradable hydrogel of chitosan

et al. 2013

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h i g h l i g h t sDicyandiamide (DCD) was encapsulated in glyoxal-crosslinked chitosan hydrogel beads. Chitosan delayed the release of nitrification inhibitor DCD in water and soil. DCD release was controlled by glyoxal polymerisation inside chitosan. The higher glyoxal polymerisation the more delayed DCD release in water or in soil. The higher glyoxal polymerisation the less DCD encapsulated in the beads. a r t i c l e i n f o b s t r a c tUsing chemical inhibitors to reduce soil nitrification decreases emissions of environmental damaging nitrate and nitrous oxide and improves nitrogen use efficiency in agricultural systems. The efficacy of nitrification inhibitors such as dicyandiamide (DCD) is limited in soil due to biodegradation. This study investigated if the persistence of DCD could be sustained in soil by slow release from a chitosan hydrogel. DCD was encapsulated in glyoxal-crosslinked chitosan beads where excess glyoxal was (i) partly removed (C beads) or (ii) allowed to dry (CG beads). The beads were tested in water and in soil. The beads contained two fractions of DCD: one which was quickly released in water, and one which was not. A large DCD fraction within C beads was readily available: 84% of total DCD bead content was released after 9 h immersion in water, while between 74% and 98% was released after 7 d in soil under low to high moisture conditions. A lower percentage of encapsulated DCD was readily released from CG beads: 19% after 9 h in water, and 33% after 7 d in soil under high rainfall conditions. Kinetic analysis indicated that the release in water occurred by quasi-Fickian diffusion. The results also suggest that DCD release was controlled by bead erosion and the leaching of glyoxal derivatives, predominantly a glyoxal-DCD adduct whose release was positively correlated with that of DCD (R 2 = 0.99, p 6 0.0001). Therefore, novel chitosan/glyoxal composite beads show a promising slow-release potential in soil for agrochemicals like DCD.

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“…In the insecticidal activity assays, both types of particle showed larvicidal activity, with the larvae of A. aegypti being successfully eliminated after an exposure period of 72 h. These findings confirmed the suitability of polysaccharides such as chitosan and cashew tree gum for use as matrices to carry bioinsecticides designed to control the proliferation of insect larvae. Quiñones et al (2010) described the use of chitosan microspheres to carry synthetic analogues of brassinosteroids and diosgenin derivatives, and tested different ligands in the reactions. The systems were characterized using FTIR and DSC, and release assays were realized in water at different pH values.…”

Section: Fernándezmentioning

confidence: 99%

Polysaccharides as safer release systems for agrochemicals

Campos

Oliveira

Fraceto

et al. 2014

Agron. Sustain. Dev.

277

175

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Agrochemicals are used to improve the production of crops. Conventional formulations of agrochemicals can contaminate the environment, in particular in the case of intensive cropping. Hence, there is a need for controlledrelease formulations of agrochemicals such as polysaccharides to reduce pollution and health hazards. Natural polysaccharides are hydrophilic, biodegradable polymers. This article reviews the use of polysaccharides in the form of micro-and nanoparticles, beads and hydrogels. The main points are: (1) slow release formulations minimize environmental impact by reducing agrochemical leaching, volatilization and degradation. For example, 50 % of the encapsulated insecticide chlorpyrifos is released in 5 days, whereas free chlorpyrifos is released in 1 day. (2) Slow release formulations increase the water-holding capacity of soil. (3) Slow release formulations better control weeds in the long run. (4) Polymer-clay formulations store ionic plant nutrients. (5) Polymer hydrogel formulations reduce compaction, erosion, and water run-off. They increase soil permeability and aeration, infiltration rates, and microbial activity, and, in turn, plant performance. In conclusion, polysaccharide formulations can be used for safer use of agrochemicals.

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Microspheres of chitosan for controlled delivery of brassinosteroids with biological activity as agrochemicals

Cited by 56 publications

References 25 publications

Hydrophobically-modified Chitosan Microspheres for Release of Diosgenin

Hydrophobically-modified Chitosan Microspheres for Release of Diosgenin

Slow delivery of a nitrification inhibitor (dicyandiamide) to soil using a biodegradable hydrogel of chitosan

Polysaccharides as safer release systems for agrochemicals

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