Plant and herbal essential oils (EOs) offer a wide range of pharmacological actions that include anticancer effects. Here, we evaluated the cytotoxic activity of EO from Lippia alba (chemotype linalool), L. alba (chemotype dihydrocarvone, LaDEO), Clinopodium nepeta (L.) Kuntze (CnEO), Eucalyptus globulus, Origanum × paniculatum, Mentha × piperita, Mentha arvensis L., and Rosmarinus officinalis L. against human lung (A549) and colon (HCT-116) cancer cells. The cells were treated with increasing EO concentrations (0–500 µL/L) for 24 h, and cytotoxic activity was assessed. LaDEO and CnEO were the most potent EOs evaluated (IC₅₀ range, 145–275 µL/L). The gas chromatography–mass spectrometry method was used to determine their composition. Considering EO limitations as therapeutic agents (poor water solubility, volatilization, and oxidation), we evaluated whether LaDEO and CnEO encapsulation into solid lipid nanoparticles (SLN/EO) enhanced their anticancer activity. Highly stable spherical SLN/LaDEO and SLN/CnEO SLN/EO were obtained, with a mean diameter of 140–150 nm, narrow size dispersion, and Z potential around −5mV. EO encapsulation strongly increased their anticancer activity, particularly in A549 cells exposed to SLN/CnEO (IC₅₀ = 66 µL/L CnEO). The physicochemical characterization, biosafety, and anticancer mechanisms of SLN/CnEO were also evaluated in A549 cells. SLN/CnEO containing 97 ± 1% CnEO was highly stable for up to 6 months. An increased in vitro CnEO release from SLN at an acidic pH (endolysosomal compartment) was observed. SLN/CnEO proved to be safe against blood components and non-toxic for normal WI-38 cells at therapeutic concentrations. SLN/CnEO substantially enhanced A549 cell death and cell migration inhibition compared with free CnEO.

Liver inflammation represents a major clinical problem in a wide range of pathologies. Among the strategies to prevent liver failure, dexamethasone (DXM) has been widely used to suppress inflammatory responses. The use of nanocarriers for encapsulation and sustained release of glucocorticoids to liver cells could provide a solution to prevent severe side effects associated with systemic delivery as the conventional treatment regime. Here we describe a nanostructured lipid carrier developed to efficiently encapsulate and release DXM. This nano-formulation proved to be stable over time, did not interact in vitro with plasma opsonins, and was well tolerated by primary non-parenchymal liver cells (NPCs). Released DXM preserved its pharmacological activity, as evidenced by inducing robust anti-inflammatory responses in NPCs. Taken together, nanostructured lipid carriers may constitute a reliable platform for the delivery of DXM to treat pathologies associated with chronic liver inflammation.

Chagas disease is a neglected endemic disease prevalent in Latin American countries, affecting around 8 million people. The first-line treatment, benznidazole (BNZ), is effective in the acute stage of the disease but has limited efficacy in the chronic stage, possibly because current treatment regimens do not eradicate transiently dormant Trypanosoma cruzi amastigotes. Nanostructured lipid carriers (NLC) appear to be a promising approach for delivering pharmaceutical active ingredients as they can have a positive impact on bioavailability by modifying the absorption, distribution, and elimination of the drug. In this study, BNZ was successfully loaded into nanocarriers composed of myristyl myristate/Crodamol oil/poloxamer 188 prepared by ultrasonication. A stable NLC formulation was obtained, with ≈80% encapsulation efficiency (%EE) and a biphasic drug release profile with an initial burst release followed by a prolonged phase. The hydrodynamic average diameter and zeta potential of NLC obtained by dynamic light scattering were approximately 150 nm and −13 mV, respectively, while spherical and well-distributed nanoparticles were observed by transmission electron microscopy. Fourier-transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and small-angle X-ray scattering analyses of the nanoparticles indicated that BNZ might be dispersed in the nanoparticle matrix in an amorphous state. The mean size, zeta potential, polydispersity index, and %EE of the formulation remained stable for at least six months. The hemolytic effect of the nanoparticles was insignificant compared to that of the positive lysis control. The nanoparticle formulation exhibited similar performance in vitro against T. cruzi compared to free BNZ. No formulation-related cytotoxic effects were observed on either Vero or CHO cells. Moreover, BNZ showed a 50% reduction in CHO cell viability at 125 µg/mL, whereas NLC-BNZ and non-loaded NLC did not exert a significant effect on cell viability at the same concentration. These results show potential for the development of new nanomedicines against T. cruzi.

Chagas disease is an endemic parasitic condition affecting Latin America and recently Europe caused by the Trypanosoma cruzi . This work proposes a new impedimetric immunosensor for the rapid, cost-effective, label-free, and low-volume detection of specific anti- T. cruzi antibodies, used as biomarkers of Chagas disease in human serum. The biosensor is based on gold screen-printed electrodes that are functionalized with isolated cruzipain proteins by adsorption, following a highly reproducible 40 minutes- chemical procedure. The biosensor is tested with clinical serum samples from patients with (positive) or without (negative) anti- T. cruzi antibodies as previously verified by ELISA testing. The detection is performed through electrochemical impedance spectroscopy, showing ~22% variation of the charge transfer resistance ( R_ct ) for positive human serum due to the immunoreaction between the immobilized cruzipain and the specific antibodies contained in the samples. Based on the cutoff value of R_ct ratios, the developed immunosensor is capable to successfully discriminate positive and negative human serum samples at a dilution factor of 1/6400 in phosphate buffered saline solution, showing an excellent agreement with the ELISA results.

Background/Objectives: Drug repurposing explores new applications for approved medications, such as simvastatin (SV), a lipid-lowering drug that has shown anticancer potential but is limited by solubility and side effects. This study aims to enhance SV delivery and efficacy against lung cancer cells using bioactive lipid nanoparticles formulated with plant-derived monoterpenes as both nanostructuring agents and anticancer molecules. Methods: Lipid nanoparticles were produced by ultrasonication and characterized for morphology, size, zeta potential, and polydispersity index (PDI). Monoterpenes (linalool-LN-, limonene, 1,8-cineole) or Crodamol^® were used as liquid lipids. Encapsulation efficiency (EE), release profiles, stability, biocompatibility, protein adsorption, cytotoxicity, and anticancer effects were evaluated. Results: The nanoparticles exhibited high stability, size: 94.2 ± 0.9–144.0 ± 2.6 nm, PDI < 0.3, and zeta potential: −4.5 ± 0.7 to −16.3 ± 0.8 mV. Encapsulation of SV in all formulations enhanced cytotoxicity against A549 lung cancer cells, with NLC/LN/SV showing the highest activity and being chosen for further investigation. Sustained SV release over 72 h and EE > 95% was observed for NLC/LN/SV. SAXS/WAXS analysis revealed that LN altered the crystallographic structure of nanoparticles. NLC/LN/SV demonstrated excellent biocompatibility and developed a thin serum protein corona in vitro. Cellular studies showed efficient uptake by A549 cells, G0/G1 arrest, mitochondrial hyperpolarization, reactive oxygen species production, and enhanced cell death compared to free SV. NLC/LN/SV more effectively inhibited cancer cell migration than free SV. Conclusions: NLC/LN/SV represents a promising nanocarrier for SV repurposing, combining enhanced anticancer activity, biocompatibility, and sustained stability for potential lung cancer therapy.