ABSTRACT
This study aimed to develop and implement a nanotechnology-based alternative to traditional tracers used in the oil and gas industry for assessing interwell connectivity. A simple and rapid hydrothermal protocol for synthesizing carbon quantum dots (CQDs) using agroindustry waste was implemented. Three commercial CQDs were employed (CQDblue, CQDgreen, and CQDred); the fourth was synthesized from orange peel (CQDop). The CQDs from waste and other commercials with spherical morphology, nanometric sizes less than 11 nm in diameter, and surface roughness less than 3.1 nm were used. These tracers demonstrated high colloidal stability with a negative zeta potential, containing carbonyl-type chemical groups and unsaturations in aromatic structures that influenced their optical behavior. All materials presented high colloidal stability with negative values of charge z potential between -17.8 and -49.1. Additionally, individual quantification of these tracers is feasible even in scenarios where multiple CQDs are present in the effluent with a maximum percentage of interference of 15.5% for CQDop in the presence of the other three nanotracers. The CQDs were injected into the field once the technology was insured under laboratory conditions. Monitoring the effluents allowed the determination of connectivity for five first-line producer wells. This study enables the application of CQDs in the industry, particularly in fields where the arrangement of injector and producer wells is intricate, requiring the use of multiple tracers for a comprehensive description of the system.
ABSTRACT
Cannabidiol (CBD) has significant therapeutic potential; nevertheless, its advance as an effective drug by the pharmaceutical business is hindered by its inherent characteristics, such as low bioavailability, low water solubility, and variable pharmacokinetic profiles. This research aimed to develop nanoliposomes using an easy and low-cost method to improve the hydrosolubility of CBD and achieve a controlled delivery of the active principle under relevant physiological conditions from the mouth to the intestine; the cytotoxic and antitumor activities were also evaluated. To achieve the objective, core-shell nanoliposomes based on CBD were synthesized in three easy steps and characterized in terms of shape, size, surface chemistry, thermal capacity, and surface charge density through transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and potential charge (PZ), respectively. CBD-controlled delivery trials were carried out under simulated mouth-duodenal conditions and fitted to Korsmeyer-Peppas and Noyes-Whitney models to conclude about the pharmacokinetics of CBD from nano-CBD. Cytotoxicity studies on nonmalignant human keratinocytes (HaCaT) were carried out to evaluate its safety and the recommended consumption dose, and finally, the antiproliferative capacity of nano-CBD on human colon carcinoma cells (SW480) was determined as beginning proposal for cancer treatment. The characterization results verified the water solubility for the CBD nanoencapsulated, the core-shell structure, the size in the nanometric regime, and the presence of the synthesis components. The dissolution rate at duodenal conditions was higher than that in buccal and stomach environments, respectively, and this behavior was associated with the shell (lecithin) chemical structure, which destabilizes at pH above 7.2, allowing the release by non-Fickian diffusion of CBD as corroborated by the Korsmeyer-Peppas model. In vitro biological tests revealed the innocuousness and cyto-security of nano-CBD up to 1000 mg·L-1 when evaluated on HaCaT cells and concentrations higher than 1000 mg·L-1 showed antitumor activity against human colon carcinoma cells (SW480) taking the first step as a chemotherapeutic proposal. These results are unprecedented and propose a selective delivery system based on nano-CBD at low cost and that provides a new form of administration and chemo treatment.
ABSTRACT
In this work, the antioxidant properties of methanolic extract of Larrea tridentata were assessed through the free radical scavenging method, ferric reducing antioxidant power and oxygen radical absorbance capacity. The phenolic acids content in the extract was quantified by high-performance liquid chromatography (HPLC) and the total phenol content by the Folin-Ciocalteu method. The extract was used as an antioxidant in biodiesel from canola oil composed mostly by fatty acid methyl esters identified and quantified by gas chromatography-mass spectrophotometry (GC-MS). The performance of the extract as an antioxidant was assessed by the oxidative stability index (OSI) with a Rancimat equipment at 100, 110, 120 and 130 °C. Additionally, the change of the peroxide value (PV) and the higher heating value under conditions of oxidative stress at 100 °C and air injection were measured. The antioxidant capacity of the extract reached 50,000 TAEC (micromole of Trolox antioxidant equivalent capacity per gram). The biodiesel was constituted by more than 70% of unsaturated fatty acid methyl esters (FAME), mainly methyl oleate. The time needed to reach a PV of 100 meqO2/kg was almost four times longer with an antioxidant concentration of 250 mg/L than the blank. The biodiesel showed an OSI time of 1.25 h at 110 °C, while it increased to 8.8, 15.89 and 32.27 h with the antioxidant at concentrations of 250, 500 and 1000 mg/L, respectively. The methanolic Larrea tridentata extract proved to have an antioxidant capacity and it is a green antioxidant in biodiesel to increase its oxidative stability. According to the results obtained, the L. tridentata methanolic extract is an alternative to the commercial synthetic antioxidants used in biodiesel nowadays.
