Agricultural and Biomedical Applications of Chitosan-Based Nanomaterials

Abstract

Chitosan has emerged as a biodegradable, nontoxic polymer with multiple beneficial applications in the agricultural and biomedical sectors. As nanotechnology has evolved as a promising field, researchers have incorporated chitosan-based nanomaterials in a variety of products to enhance their efficacy and biocompatibility. Moreover, due to its inherent antimicrobial and chelating properties, and the availability of modifiable functional groups, chitosan nanoparticles were also directly used in a variety of applications. In this review, the use of chitosan-based nanomaterials in agricultural and biomedical fields related to the management of abiotic stress in plants, water availability for crops, controlling foodborne pathogens, and cancer photothermal therapy is discussed, with some insights into the possible mechanisms of action. Additionally, the toxicity arising from the accumulation of these nanomaterials in biological systems and future research avenues that had gained limited attention from the scientific community are discussed here. Overall, chitosan-based nanomaterials show promising characteristics for sustainable agricultural practices and effective healthcare in an eco-friendly manner.

Keywords: abiotic stress; cancer photothermal therapy; chitosan; foodborne pathogens; nanoparticles; water purification.

Figure 1

Process of chitosan production starting with different sources. The figure was created using ACD/ChemSketch and Adobe Illustrator 2020.

Figure 2

Schematic representation of the efficient removal of oil droplets from emulsified oil wastewater with aminopropyl-functionalized silica (APFS) coated, chitosan-grafted magnetic nanoparticles. An enhanced demulsification effect was observed after grafting with chitosan under all the tested pH conditions. Reproduced with permission from Reference [26] Copyright © 2017 Elsevier.

Figure 3

Comparison of maize plants under salt stress treated with free S-nitroso-mercaptosuccinic acid (MSA) to the plants treated with chitosan nanoparticles encapsulating S-nitroso-MSA at 50 or 100 µM concentration. It shows that the treatment with S-nitroso-MSA-Chitosan nanoparticles at both concentrations was effective in relieving the visible effects (necrosis) of salt stress in the plants compared to free S-nitroso-MSA, which has shown to be effective only at 100 µM concentration. Control plants were treated only with distilled water or salt without any treatment. Reproduced with permission from Reference [51] Copyright© 2016 Elsevier.

Figure 4

(A) Scanning Electron Microscopy images showing CSNPs and (B) Cyperus articulatus Essential oil (CPEO) loaded CSNPs synthesized with 1:0.25 weight ratio of chitosan to essential oil. (C) Initial analysis of the antimicrobial effect of CSNPs-CPEO using disc diffusion method with S. aureus and (D) E. coli together with control experiments. In figures (C) and (D), the inhibition zone for free essential oil is indicated as 1a and 2a, respectively. Similarly, 1b and 2b show CSNPs-CPEO inhibition zone, 1c and 2c: empty disc used as the negative control, and 1d and 2d: Ciprofloxacin used as the positive control. Reproduced with permission from Reference [87] Copyright © 2019 Elsevier.

Figure 5

The use of polymeric chitosan in the formulation of a multifunctional chemo-phototherapeutic agent. Chitosan was used as a reducing and stabilizing agent for reduced graphene oxide nanoflakes and also served as a shell to entrap DOX and IR820 dye at different ratios. Reproduced with permission from Reference [122] Copyright © 2019 Elsevier.

Figure 6

(A) Preparation of hydroxyethyl chitosan derivative (HECS) and hyaluronic acid (HA) coated gold nanorods functionalized with aldehyde/catechol- hyaluronic acid (DAHA) and loaded with DOX (gold nanorod-DAHA^DOX-HECS-HA), as a charge reversal, pH/NIR responsive therapeutic agent. (B) The charge-reversible nature of gold nanorod-DAHA^DOX-HECS-HA was analyzed by measuring the zeta potentials at different pH values. When the pH of the media was reduced from 8.0 to 5.0, the zeta potential increased from −18.9 to 15.7 mV, indicating charge reversal. (C) TEM image of gold nanorod-DAHA^DOX-HECS-HA showing the shell thickness of 2.2 nm. Reproduced with permission from Reference [128] Copyright © 2019 Elsevier.