Publications by authors named "Lilia C Courrol"

The type of material used in packaging, lighting, and storage time can impact food quality during storage. This study aimed to investigate the progress of photosensitized oxidation in refined soybean oil using steady-state and time-resolved fluorescence spectroscopy. The experiment was conducted through accelerated photo-oxidation with Light-Emitting Diode (LED) in samples stored for ten days at room temperature (26.

View Article and Find Full Text PDF

L-Cysteine (Cys) is a non-essential sulfur-containing amino acid, crucial for protein synthesis, detoxification, and several metabolic functions. Cys is widely used in the agricultural, food, cosmetic, and pharmaceutical industries. So, a suitable sensitive and selective sensing approach is of great interest, and a low-cost sensor would be necessary.

View Article and Find Full Text PDF

Aminolevulinic acid (ALA) is considered one of the most critical plants growth regulators and essential precursors for chlorophyll biosynthesis; besides, its photodynamic activity can be used to exterminate larvae and microorganisms in plants and soil. Silver nanoparticles (AgNPs) have unique physicochemical properties and potent antimicrobial, antiviral, and antifungal activities, and in agriculture, their application as nanopesticides has been proposed. In this study, silver and silver-iron nanoparticles capped/stabilized with aminolevulinic acid (ALAAgNPs and ALAAgFeNPs) were synthesized by the photoreduction method and characterized by UV-vis spectroscopy, transmission electron microscopy, and zeta potential analysis.

View Article and Find Full Text PDF

The increased number of resistant microbes generates a search for new antibiotic methods. Metallic nanoparticles have emerged as a new platform against several microorganisms. The nanoparticles can damage the bacteria membrane and DNA by oxidative stress.

View Article and Find Full Text PDF

, known as Brazilian cherry, is widely distributed in Brazil, Argentina, Uruguay, and Paraguay. L. extracts contain phenolic compounds, such as flavonoids, tannins, triterpenes, and sesquiterpenes.

View Article and Find Full Text PDF
Article Synopsis
  • * Biosensing techniques, particularly those using fluorescence, show promise for quick identification of foodborne pathogens in poultry.
  • * The study found that fluorescence properties in chicken meat contaminated with Salmonella increased over time, with specific compounds, NAD(P)H and coproporphyrin, indicating the potential for rapid detection methods.
View Article and Find Full Text PDF

Gold nanoparticles have been intensively studied in cancer therapy to improve drug release, increasing therapeutic action and reducing adverse effects. The interaction between gold nanoparticles and cell membranes can give information about the cell internalization. In this study, gold nanoparticles with aminolevulinic acid (5-ALA) were synthesized using the photoreduction method (5-ALA: AuNPs).

View Article and Find Full Text PDF

Background: SARS-CoV-2 attacks hemoglobin through its structural protein ORF3a, dissociating the iron from the heme, as iron is necessary by cell machinery for virus replication. In this process protoporphyrin (PpIX) is released.

Methods: The decrease in the hemoglobin levels observed in patients with Covid-19 is frequently accompanied by an increase in PpIX levels.

View Article and Find Full Text PDF

This work aims to investigate changes induced by low-energy radiation in adipose and muscular tissues employing autofluorescence and Raman spectroscopic techniques. X-ray beams expositions with 25 and 35 kV at 0.11, 1.

View Article and Find Full Text PDF

Background: Nanoparticles show promise for theranostic applications in cancer. The metal-based nanoparticles can be used both as photosensitizers and delivery vehicles. In bimetallic particles based on gold or silver and iron, a combination of the plasmonic features of the gold or silver components with the magnetic properties of the iron makes these hybrid nanomaterials suitable for both imaging and therapeutic applications.

View Article and Find Full Text PDF

The high rates of antibiotics use in hospitals have resulted in a condition where multidrug-resistant pathogens have become a severe threat to the human health worldwide. Therefore, there is an increasing necessity to identify new antimicrobial agents that can inhibit the multidrug-resistant bacteria and biofilm formation. In this study, antibacterial and anti-biofilm activities of tryptophan silver nanoparticles (TrpAgNP) were investigated.

View Article and Find Full Text PDF

Background: Experimental models of prostate cancer have demonstrated increased levels of protoporphyrin IX (PpIX) in the blood and faeces of mice. Hence, the quantification of these autofluorescent molecules could be hypothesized to be a potential marker for this type of tumour. In this case-control study, the autofluorescence of porphyrins in human faeces from patients with prostate cancer and control subjects was analysed using fluorescence spectroscopy.

View Article and Find Full Text PDF

Sonodynamic therapy (SDT) is emerging as new atherosclerosis treatment. The use of gold nanoparticles (AuNPs) as the vehicle for a sensitizer delivery improves reactive oxygen species formation. In this study, methyl ester of aminolevulinic acid (MALA) gold nanoparticles (MALA:AuNPs) functionalized with polyethylene glycol (PEG) were synthesized by photoreduction and characterized by ultraviolet/visible optical absorption, zeta potential and electron microscopy.

View Article and Find Full Text PDF

Standard lipoprotein measurements of triglycerides, total cholesterol, low-density lipoproteins (LDL), and high-density lipoproteins (HDL) fail to identify many lipoprotein abnormalities that contribute to cardiovascular heart diseases (CHD). Studies suggested that the presence of CHD is more strongly associated with the HDL subspecies than with total HDL cholesterol levels. The HDL particles can be collected in at least three subfractions, the HDL2b, HDL2a, and HDL3.

View Article and Find Full Text PDF

The synthesis of nanoparticles is usually carried out by chemical reduction, which is effective but uses many toxic substances, making the process potentially harmful to the environment. Hence, as part of the search for environmentally friendly or green synthetic methods, this study aimed to produce silver nanoparticles (AgNPs) using only AgNO, Milli-Q water, white light from a xenon lamp (Xe) and amino acids. Nanoparticles were synthetized using 21 amino acids, and the shapes and sizes of the resultant nanoparticles were evaluated.

View Article and Find Full Text PDF

The objective of this study is to characterize arterial tissue with and without atherosclerosis by fluorescence lifetime imaging microscopy (FLIM) using Europium Chlortetracycline complex (EuCTc) as fluorescent marker. For this study, twelve rabbits were randomly divided into a control group (CG) and an experimental group (EG), where they were fed a normal and hypercholesterolemic diet, respectively, and were treated for 60 days. Cryosections of the aortic arch specimens were cut in a vertical plane, mounted on glass slides, and stained with Europium (Eu), Chlortetracycline (CTc), Europium Chlortetracycline (EuCTc), and Europium Chlortetracycline Magnesium (EuCTcMg) solutions.

View Article and Find Full Text PDF

Renal cell carcinoma (RCC) remains one of the greatest challenges of urological oncology and is the third leading cause of death in genitourinary cancers. Surgery may be curative when patients present with localized disease. Our previous results demonstrated the autofluorescence of blood PpIX in primary RCC mouse model and an increase in fluorescence intensity as a function of growth of the subcutaneous tumor mass.

View Article and Find Full Text PDF

In this study, 5-aminolevulinic acid (ALA) gold nanoparticles (ALA:AuNPs) functionalized with polyethylene glycol (PEG) were synthesized and administered to rabbits to evaluate their use in clinical practice as theranostic agents for atherosclerosis. This was done by measuring the porphyrin fluorescence extracted from the rabbits' blood and feces. An increase in blood and feces porphyrin emission after ALA:AuNP administration suggests that ALA was incorporated by gold nanoparticles, its structure was preserved, and a rapid conversion into endogenous porphyrins occurred, overloading the synthetic pathway that led to protoporphyrin IX (PPIX) accumulation.

View Article and Find Full Text PDF

A simple, environmentally friendly and cost-effective method was used to synthesize silver nanoparticles using tryptophan and light. To prepare the nanoparticles, the following components were used: deionized water, silver nitrate, light and tryptophan. The effects of the tryptophan concentration and light exposure time on the formation of tryptophan silver nanoparticles (Tnnps) were studied.

View Article and Find Full Text PDF

Protoporphyrin IX (PPIX), a derivative of hematoporphyrin, can accumulate in rapidly growing tissues, including tumors and atherosclerotic plaques. The objective of this study is to employ PPIX fluorescence to detect the changes in blood caused by the formation of atheromatous plaques in arteries; this measurement can function as a liquid biopsy. For this purpose twenty four rabbits were randomly divided into groups: control group (CG)--fed with a normal diet, and an experimental group (EG)--fed with a hypercholesterolemic diet (1% cholesterol).

View Article and Find Full Text PDF

In this paper we report the effects of the irradiation of low-density lipoprotein (LDL) by ultra-short laser pulses to obtain in vitro alterations mimicking proatherogenic modifications occurring in vivo in LDL. The modifications by metallic ions (copper and iron) and ultra-short laser pulses were studied by fluorescence steady state and time-resolved lifetime measurements. The results demonstrate that the modifications caused by ultra-short laser pulses and by iron affect the tryptophan residues of apolipoprotein B-100 (Apo-B), slightly decreasing fluorescent lifetimes, with almost no modifications in pre-exponential factors, indicating preservation of structural properties around the fluorophore.

View Article and Find Full Text PDF

This paper describes the elimination of porphyrins by feces. It was demonstrated that porphyrin accumulates substantially more in tumors than in normal tissues, and consequently more PPIX reaches the blood of patients and animals with tumors, and then, it needs to be eliminated. The fluorescence of feces revealed that there are large amounts of PPIX in the excreta of animals with cancer comparing with healthy animals.

View Article and Find Full Text PDF

Normal prostate tissue contains high levels of citrate. In the presence of prostate cancer, the citrate level is diminished. In this paper we show that it is possible to use europium-oxytetracycline complex as a citrate fluorescent probe and consequently as a prostate cancer probe.

View Article and Find Full Text PDF

Pseudomonas aeruginosa is considered one of the most important pathogens that represent life-threatening risk in nosocomial environments, mainly in patients with severe burns. Antimicrobial photodynamic therapy (aPDT) has been effective to kill bacteria. The purpose of this study was to develop a burn wound and bloodstream infection model and verify aPDT effects on it.

View Article and Find Full Text PDF

Background: The objective of this paper was to verify if the oral administration of δ-aminolevulinic acid (ALA) in animals with prostate tumor can increase the sensitivity of cancer diagnosis by protoporphyrin IX blood autofluorescence. In this study, the autofluorescence of blood porphyrin was analyzed using fluorescence spectroscopy on healthy male NUDE mice and in those with prostate cancer induced by the inoculation of DU145 cells.

Methods: A total of 18 male NUDE mice, ∼8 weeks old on arrival were divided into 3 groups: Control, Tumor and ALA Tumor.

View Article and Find Full Text PDF