# Multifunctional biofunctionalized hybrid nanoantifungals with novel active coating agents based on cinnamaldehyde- and β-cyclocitral-modified polydopamine

## TL;DR

This paper introduces new hybrid nanoparticles that fight fungal pathogens and promote plant growth, offering a sustainable alternative to traditional pesticides.

## Contribution

The novelty lies in the development of multifunctional antifungal nanoparticles with pH-responsive release and plant growth promotion capabilities.

## Key findings

- Nanoparticles released up to 94% geraniol and 81% β-cyclocitral at pH 5, showing pH-responsive behavior.
- Antifungal activity was strong with MICs as low as 0.078 mg/mL and visible mycelial disruption.
- Treated plants showed improved germination, growth, and physiological markers under fungal stress.

## Abstract

Fungal pathogens pose serious threats to global agriculture, causing substantial crop loss and food security concerns. Current solutions often rely on conventional pesticides, generating negative environmental impacts. This study presents the development of two novel multifunctional hybrid nanoparticles designed to provide a sustainable alternative for crop protection and growth promotion. These nanoparticles are based on dendritic mesoporous silica nanoparticles (dMSNs) and functionalized with innovative coating agents derived from cinnamaldehyde- (CIN) and β-cyclocitral (βETA) -modified polydopamine (DOPA). The purpose of this research was to create a system that could deliver antifungal agents and support plant development simultaneously, especially under pathogen-induced stress. Nanoparticles exhibited a dual-release mechanism with pH-responsive kinetics, releasing up to 94 % of geraniol (GER) and 81 % of compound βETA, at pH 5. This confirms their ability for targeted, stimulus-triggered delivery. In vitro tests showed strong antifungal activity against several plant pathogenic fungi, with minimum inhibitory concentrations down to 0.078 mg/mL. Microscopic analysis revealed significant disruption of fungal mycelia after treatment, confirming the antifungal mechanism. In vivo biosafety was established through assays on Drosophila melanogaster. Furthermore, experiments on plants infected with Fusarium oxysporum demonstrated enhanced seed germination and early plant development. Treated plants showed improved root and shoot growth, higher chlorophyll content, and restored levels of key physiological markers like polyphenols and carotenoids. This study reports two dual-functional nanoparticles that improve the control of fungal pathogens while simultaneously promoting early plant development. The findings highlight their potential as sustainable nanobiotechnological tools for protecting crops and enhancing productivity in agricultural systems affected by fungal diseases.

Image 1

•Cinnamaldehyde- and β-cyclocitral-modified polydopamine coatings on dMSNs create multifunctional antifungal nanoformulations.•pH-responsive dual release: up to 94 % geraniol and 81 % β-cyclocitral released at pH 5.•Antifungal efficacy: minimum inhibitory concentrations (MICs) as low as 0.078 mg mL−1, with marked mycelial disruption.•Seed nanopriming in wheat: restored germination/seedling emergence and metabolites under F. oxysporum challenge.•In vivo biosafety: no significant toxicity in the Drosophila melanogaster model.

Cinnamaldehyde- and β-cyclocitral-modified polydopamine coatings on dMSNs create multifunctional antifungal nanoformulations.

pH-responsive dual release: up to 94 % geraniol and 81 % β-cyclocitral released at pH 5.

Antifungal efficacy: minimum inhibitory concentrations (MICs) as low as 0.078 mg mL−1, with marked mycelial disruption.

Seed nanopriming in wheat: restored germination/seedling emergence and metabolites under F. oxysporum challenge.

In vivo biosafety: no significant toxicity in the Drosophila melanogaster model.