# Tilapia Bone-Derived Hydroxyapatite Particles for Controlled Citronella (Cymbopogon nardus) Release and Antimicrobial Activity

## TL;DR

This paper explores using fish bone-derived particles to control the release of citronella oil, which shows strong antimicrobial effects.

## Contribution

A sustainable method using tilapia bone-derived hydroxyapatite for controlled citronella oil release and antimicrobial applications is proposed.

## Key findings

- Hydroxyapatite particles from tilapia bones can encapsulate citronella oil in a sodium alginate matrix.
- Intermediate hydroxyapatite content provided optimal controlled release and highest antimicrobial activity against E. coli.
- The method offers a sustainable way to use animal waste in biomedicine and food preservation.

## Abstract

This study investigated
the use of nanostructured hydroxyapatite
(HA) derived from tilapia (Oreochromis niloticus) bones to produce particles for encapsulating citronella essential
oil within a sodium alginate matrix, aimed at antimicrobial applications.
Particles were obtained by emulsifying sodium alginate, citronella
essential oil, and HA in different proportions, followed by dripping
the emulsion into a CaCl2 solution. Rheological properties
were characterized by rotational rheometry to assess emulsion stability,
thixotropy, and viscosity. All emulsions exhibited pseudoplastic and
thixotropic behavior, with viscosity decreasing as HA concentration
increased. While higher HA content improved emulsion stability, it
reduced thixotropy, resulting in lower encapsulation efficiency. Release
kinetics indicated that the formulation with intermediate HA content
enabled more controlled essential oil release. In antimicrobial assays,
this formulation achieved the highest activity against Escherichia coli, with an inhibition halo of 34 ±
3 mm. The results propose a sustainable strategy for enhancing controlled
release and antimicrobial performance of encapsulated agents, employing
biocompatible materials derived from animal waste, with potential
applications in biomedicine, food preservation, and environmental
protection.