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This work aimed to extract and synthesize lignin nanoparticles with effective antibacterial, antioxidant, and sunscreen properties from Oxytenanthera abyssinic.

April 10, 2026Open Access

Self-assembly synthesis of lignin nanoparticles from Oxytenanthera abyssinic using 1,4-dioxane for antibacterial, antioxidant, and sunscreen properties

Key Points

This work aimed to extract and synthesize lignin nanoparticles with effective antibacterial, antioxidant, and sunscreen properties from Oxytenanthera abyssinic.
Extracted soda lignin from Oxytenanthera abyssinic stems using alkaline treatment.
Applied a 1, 4-dioxane-based nanoprecipitation technique for self-assembly of lignin nanoparticles.
Optimized extraction through temperature (23–120°C), time (1–24 hours), and NaOH concentration (5–15%).
Conducted functional evaluations including DPPH assays for antioxidant activity, SPF measurements, and antibacterial testing against Gram-positive and Gram-negative strains.
Produced up to 294 mg/g of soda lignin with OA-LNPs showing a size range of 65 to 135 nm.
OA-LNPs exhibited a zeta potential of -30.1 mV and maintained essential phenolic functionalities.
Antioxidant activity of OA-LNPs was 11.47 µg/mL, significantly better than soda lignin's 131.1 µg/mL.
SPF measurements of commercial lotions improved by adding OA-LNPs, reaching 114.8±1.3.
Moderate antibacterial efficacy demonstrated with inhibition zones between 12.43±0.90 to 28.8±1.11 mm.

Abstract

Lignin, a renewable aromatic polymer found in lignocellulosic biomass, has several potential uses due to its antioxidant, antibacterial, and UV-absorbing qualities. The aim of this work was to extract soda lignin for sunscreen, antioxidant, and antibacterial properties from Oxytenanthera abyssinic (Ethiopian lowland bamboo) stems using an alkaline treatment. A 1, 4-dioxane-based nanoprecipitation technique was then used to create lignin nanoparticles produced from O. abyssinica (OA-LNPs) via a self-assembly process. The extraction procedure was optimized with temperature (23–120°C), time (1–24 hours) and NaOH concentration (5–15%). 1, 4-Dioxane-based nanoprecipitation was used to synthesis OA-LNPs which were then examined using SEM, EDX UV-Vis, FTIR and 1 HNMR for morphology size zeta potential and chemical structure. Antioxidant activity using DPPH assays, sun protection factor (SPF) measurements in commercial lotions and antibacterial testing against Gram-positive ( S. aureus and S . epidermidis ) and Gram-negative ( E. coli and K. pneumoniae ) strains were among the functional evaluations. Up to 294 mg/g of soda lignin were produced by the extraction. OA-LNPs had a spherical shape size ranging from 65 to 135 nm (mean 115 nm) a zeta potential of -30. 1 mV and no sulfur was found. They also retained phenolic and aromatic functionalities. The antioxidant activity of OA-LNPs was 11. 47 µg/mL which was higher than that of soda lignin (131.1 µg/mL). Due to UV absorption by phenolic groups SPF evaluations showed improvements in commercial lotions up to 114.8±1.3 when OA-LNPs were added. Antibacterial testing showed moderate efficacy against the tested strains with inhibition zones ranging from 12.43± 0.90 to 28.8± 1.11 mm. With better bioavailability and multifunctionality than Soda lignin (SL) these results highlight the environmentally friendly valorization of lignin from underutilized biomass and position OA-LNPs as promising candidates for sustainable applications in food packaging cosmetics and biomedicine.

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Limenew Abate Worku (Wed,) studied this question.

synapsesocial.com/papers/69d895046c1944d70ce05fbd https://doi.org/https://doi.org/10.1177/18479804261441856

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