Biosurfactant Screening for Green-Stabilized Wolffia arrhiza Nanosuspensions

Abstract

Problem. Developing stable nanosuspensions from plant-based materials such as Wolffia arrhiza requires effective stabilizers to prevent aggregation and achieve uniform particle dispersion. Conventional synthetic surfactants may raise environmental and safety concerns, underscoring the need for biocompatible biosurfactant alternatives. Purpose. This study aimed to screen several biosurfactants for their ability to stabilize W. arrhiza nanosuspensions, based on particle size and polydispersity index (PI) measured after key processing stages. Methods. Nanosuspensions were prepared using 5,000 mg of W. arrhiza dispersed in aqua demineralisata and stabilized with 0.5% (w/v) of one of seven biosurfactants: Emulsan, Liposan, Rhamnolipid, Trehaloselipid, Fengisin, Viscosin, and Fosfolipid. The process included (1) initial dispersion using Ultra-Turrax at 15,000 rpm for 10 minutes, followed by (2) premilling via high-pressure homogenization (HPH) at 300 bar (1 cycle) and 500 bar (2 cycles). Particle size and PI were assessed after both stages using dynamic light scattering. Main findings.  After premilling, Fosfolipid produced the smallest particle size (841.4 nm± 1.24) and lowest PI (0.335±0,01), indicating superior stabilization. Trehaloselipid also showed favorable performance, generating particles below 1,000 nm with moderate PI values. In contrast, Viscosin resulted in the largest particle size (1050.3 nm± 1.56) and highest PI (0.610± 0.06). Overall, biosurfactants with phospholipid and glycolipid characteristics outperformed polymeric or lipoprotein-based stabilizers. Conlusions. Fosfolipid emerged as the most effective stabilizer for producing stable and uniformly dispersed W. arrhiza nanosuspensions. These findings support the potential of biosurfactant-assisted green processing for nanoformulations, providing a sustainable alternative to synthetic stabilizers while maintaining nanosuspension quality