Nanostructured lipid carriers (NLC) represent the second generation of nanoparticles, offering numerous advantages over conventional delivery systems. These include improved stability, enhanced drug-loading capacity, and controlled release profiles, making them highly attractive candidates for a wide range of therapeutic applications. Their suitability for hydrophobic drugs like a traditional medicinal plant of Thailand as clove oil and alpha-mangostin. We investigated into nanostructured lipid carriers loaded with Alpha-Mangostin and clove oil (NLC-AMCO) into the physicochemical and biological characteristics to identify the formulation with the highest efficacy for treatment. The particle size, charge, polydispersity index, and other characterizations were recorded. The realtime ex vivo penetration was explored using canine gingival tissue. Drug sustained release was assessed by HPLC. Moreover, the antibacterial properties were tested by conventional methods. The NLC-AMCO can be stored at up to 40 °C for 60 days without any alterations in particle characteristics. Gingival tissue penetration and sustained drug release were superior compared to unencapsulated counterparts. It exhibited greater effectiveness in inhibiting bacterial growth than the antibiotics tested, particularly against bacteria from the oral cavities of dogs. Therefore, this alternative treatment approach offers cost-effectiveness and ease of administration for pet owners and reduces discomfort for the animals during restraint.

The increasing demand for sustainable disease management in aquaculture has intensified interest in plant-based therapeutics. This study evaluated the formulation and efficacy of andrographolide-loaded nanostructured lipid carriers (AND-NLCs) in Nile tilapia (Oreochromis niloticus) challenged with Streptococcus agalactiae ENC06. AND-NLCs were prepared by the phase-inversion technique and characterized by dynamic light scattering, transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and in vitro release profiling. Antibacterial activity was assessed by measuring inhibition zone diameters, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). Growth performance, feed utilization, hepatosomatic index (HSI), and disease resistance were evaluated over a 60-day feeding trial. The AND-NLCs exhibited an optimal particle size (189.6 nm), high encapsulation efficiency (90.58%), sustained release, and structural stability. Compared to the free AND and control group, AND-NLC supplementation significantly improved growth, feed efficiency, HSI, and positive allometric growth. It also enhanced survival (73.3%) and relative percent survival (RPS = 65.6%) following S. agalactiae ENC06 infection. Antibacterial efficacy and physiological responses showed positive correlations with nanoparticle characteristics. These findings suggest that AND-NLCs enhance bioavailability and therapeutic efficacy, supporting their potential as a functional dietary additive to promote growth and improve disease resistance in tilapia aquaculture.

Background and Aim: Streptococcosis caused by Streptococcus agalactiae represents a major constraint to Nile tilapia (Oreochromis niloticus) aquaculture, resulting in substantial economic losses. Curcumin (CUR) possesses antioxidant, antimicrobial, and immunomodulatory properties, but its practical application is limited by poor aqueous solubility and low bioavailability. This study aimed to develop CUR encapsulated in nanostructured lipid carriers (CUR-NLCs) and evaluate their effects on growth performance, feed utilization efficiency, and resistance against S. agalactiae infection in Nile tilapia. Materials and Methods: CUR-NLCs were synthesized using a phase-inversion compositional technique and characterized for particle size, polydispersity index, zeta potential, encapsulation efficiency, and release behavior. A 60-day feeding trial was conducted using four dietary treatments: a control diet, a free CUR diet (2000 mg/kg feed), CUR-NLCs containing an equivalent amount of CUR, and blank nanostructured lipid carriers. Growth performance, feed utilization indices, hepatosomatic index, and length–weight relationships were evaluated. Antibacterial activity against S. agalactiae isolates was determined, followed by experimental challenge with strain ENC06 to assess survival responses. Results: CUR-NLCs exhibited favorable physicochemical characteristics, including a mean particle size of 215.6 nm, a low polydispersity index (0.145), and a high encapsulation efficiency (98.79%), along with sustained-release properties. CUR-NLCs produced larger inhibition zones against S. agalactiae than free CUR. Fish receiving the CUR-NLC diet demonstrated significantly higher final body weight, weight gain, specific growth rate, feed intake, and protein efficiency ratio than the control group (p < 0.05). Positive allometric growth (b = 3.278) and improved relative condition factor were observed in CUR-NLC-fed fish. Following bacterial challenge, CUR-NLC supplementation resulted in the lowest mortality (11.1%), highest survival (88.9%), and highest relative percent survival (82.4%). Cox proportional hazards analysis indicated an approximately 86% reduction in mortality risk compared with infected controls. Conclusion: Dietary administration of CUR encapsulated in nanostructured lipid carriers improved growth performance, feed utilization efficiency, and post-challenge survival of Nile tilapia. These findings demonstrate that CUR-NLCs represent a promising phytobiotic-based nutritional strategy for enhancing fish health and promoting sustainable tilapia aquaculture. Keywords: aquaculture, curcumin, disease resistance, feed efficiency, nanostructured lipid carriers, Nile tilapia, streptococcosis, sustained release.