Chitosan-TPP Nanoparticles: A Potential Biocompatible Growth Promotor Diet in Fish Aquaculture

This study reports the successful synthesis and characterization of chitosan-TPP nanoparticles and their evaluation as a dietary supplement for improving the growth performance of tilapia (Oreochromis niloticus). Chitin was deacetylated to chitosan using HCl and NaOH, achieving a degree of deacetylation (DD) of approximately 85%, confirmed by FTIR analysis through the disappearance of amide I (1655 cm⁻¹) and amide II (1550 cm⁻¹) peaks and the appearance of a broad O–H/NH₂ peak at ~3400 cm⁻¹. XRD analysis revealed reduced crystallinity compared to chitin, indicating the amorphous nature of chitosan, while TGA confirmed its thermal stability with a degradation temperature around 280°C.Chitosan-TPP nanoparticles were synthesized via ionic gelation using tripolyphosphate (TPP) as a cross-linking agent. FTIR spectra showed key peaks at 3199.91 cm⁻¹ (O–H and N–H stretching) and 1150–1000 cm⁻¹ (P–O stretching), confirming successful incorporation of TPP and ionic crosslinking. XRD analysis indicated a combination of crystalline and amorphous regions, with characteristic peaks at 2θ = 14.3°, 20.2°, 29.6°, and 32.0°. SEM analysis revealed nanoparticles with sizes ranging from 100–300 nm, smooth surface morphology, and some aggregation due to high surface energy. The encapsulation efficiency (EE) of the nanoparticles was ~80%, highlighting their suitability for controlled release applications. In a feeding trial, chitosan-TPP nanoparticles were incorporated into a formulated diet to assess their effects on tilapia growth. Weight-Length Ratio (WLR) analysis revealed consistent growth in the nanoparticle-treated group (WLR range: 0.34–1.36) compared to the control (WLR range: 0.44–3.43). The treated group demonstrated significantly higher weight gain (24.17 ± 12.81 g) compared to the control (14.06 ± 6.11 g) and a lower food conversion ratio (FCR: 0.097 vs. 0.161), indicating improved feed utilization efficiency. The survival rate was 100% in both groups, with feed intake values of 2.34 ± 0.19 g (treated) and 2.27 ± 0.20 g (control). These results suggest that chitosan-TPP nanoparticles significantly enhance growth performance and nutrient absorption in tilapia, offering promising applications in functional feeds for aquaculture.