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Cerenkov radiation (CR) can be used as an internal light source in photodynamic therapy (PDT). Methotrexate (MTX) and paclitaxel (PTX), chemotherapeutic agents with wide clinical use, have characteristics of photosensitizers (PS). This work evaluates the possibility of photoexciting MTX and PTX with CR from

Recently, it was demonstrated that doxorubicin (Dox.HCl), a chemotherapeutic agent, could be photoactivated by Cerenkov radiation (CR). The objective of the present work was to develop a multimodal chemotherapy-radiotherapy-photodynamic therapeutic system based on reconstituted high-density lipoprotein (rHDL) loaded with Dox.HCl and 177Lu-DOTA. 177Lu acts as a therapeutic radionuclide and CR source. The system can be visualized by nuclear imaging. Fluorescence microscopy showed that rHDL-Dox specifically recognized cancer cells (T47D) that are positive for SR-B1 receptors. Encapsulated Dox.HCl was released into the cells and produced reactive oxygen species when irradiated with a 450-nm laser (photodynamic effect). The same effect occurred when Dox.HCl was irradiated by 177Lu CR. Through in vitro experiments, it was confirmed that the addition of 177Lu-DOTA to the rHDL-Dox nanosystem did not affect the specific recognition of SR-B1 receptors expressed in cells, or the cellular internalization of 177Lu-DOTA. The toxicity induced by the rHDL-Dox/177Lu nanosystem in cell lines with high (T47D and PC3), poor (H9C2) and almost-zero (human fibroblasts (FB)) expression of SR-B1 was evaluated in vitro and confirmed the synergy of the combined chemotherapy-radiotherapy-photodynamic therapeutic effect; this induced toxicity was proportional to the expression of the SR-B1 receptor on the surface of the cells used. The HDL-Dox/177Lu nanosystem experienced uptake by tumor cells and the liver-both tissues with high expression of SR-B1 receptors-but not by the heart. 177Lu CR offered the possibility of imparting photodynamic therapy where laser light could not reach.

Main aim: To electrophysiologically determine the impact of moderate to severe chronic hypoxia (H) resulting from a wide array of CHD (HCHD) conditions on the integrity of brainstem function. Materials and methods: Applying brainstem auditory-evoked response methodology, 30 chronically afflicted HCHD patients, who already had undergone heart surgery, were compared to 28 healthy control children (1–15 yo) matched by age, gender and socioeconomic condition. Blood oxygen saturation was clinically determined and again immediately before brainstem auditory-evoked response testing. Results: Among HCHD children, auditory wave latencies (I, III and V) were significantly longer (medians: I, 2.02 ms; III, 4.12 ms, and; V, 6.30 ms) compared to control (medians: I, 1.67ms; III, 3.72 ms, and; V, 5.65 ms), as well as interpeak intervals (HCHD medians: I-V, 4.25 ms, and; III-V, 2.25ms; control medians: I-V, 3.90 ms and, III-V, 1.80 ms) without significant differences in wave amplitudes between groups. A statistically significant and inverse correlation between average blood oxygen saturation of each group (control, 94%; HCHD, 78%) and their respective wave latencies and interpeak intervals was found. Conclusions: As determined by brainstem auditory-evoked responses, young HCHD patients manifestly show severely altered neuronal conductivity in the auditory pathway strongly correlated with their hypoxic condition. These observations are strongly supported by different brainstem neurological and image studies showing that alterations, either in microstructure or function, result from the condition of chronic hypoxia in CHD. The non-altered wave amplitudes are indicative of relatively well-preserved neuronal relay nuclei.

We present the draft genome sequence of the halotolerant strain Bacillus paralicheniformis TXO7B-1SG6.

The search for methods that identify early toxicity, induced by chemotherapy, is urgent. Changes in the biodistribution of radiopharmaceuticals could give information on early toxicity. Ten-week-ol...

Hybrid nanosystems have useful properties for preparing therapeutic systems. Among the most commonly used inorganic components in hybrid nanosystems are gold nanoparticles (AuNP). The design of these nanosystems may require AuNP of hydrophilic or hydrophobic nature. Upon irradiation of AuNP, reactive oxygen species (ROS) are formed, and the temperature of the surrounding medium rises, depending on the size, shape and structure of the nanoparticle. The aim of this work is to evaluate whether irradiating 5 nm spherical gold nanoparticles both ‘bare’ (AuNP) and functionalized with dodecanethiol (AuNPf) with a Nd:YAG pulsed laser (30 ps, and 10 Hz) at wavelengths of 532 nm (0.031 J cm−2) and 1064 nm (1.91 J cm−2) produces ROS and heat sufficiently to induce cytotoxicity, or to demonstrate whether functionalization significantly influences such processes. It was verified by UV–vis spectrophotometry with ABMA and DCPIP that AuNP and AuNPf in solution induced ROS formation. They also produce a moderate elevation of the temperature of the surrounding medium. Irradiation of T47D cells at 532 nm in the presence of AuNP significantly decreased cell viability (>60%) compared to irradiation in the absence of NP (

Actinium-225 and other alpha-particle-emitting radionuclides have shown high potential for cancer treatment. Reconstituted high-density lipoproteins (rHDL) specifically recognize the scavenger receptor B type I (SR-BI) overexpressed in several types of cancer cells. Furthermore, after rHDL-SR-BI recognition, the rHDL content is injected into the cell cytoplasm. This research aimed to prepare a targeted 225Ac-delivering nanosystem by encapsulating the radionuclide into rHDL nanoparticles. The synthesis of rHDL was performed in two steps using the microfluidic synthesis method for the subsequent encapsulation of 225Ac, previously complexed to a lipophilic molecule (225Ac-DOTA-benzene-p-SCN, CLog P = 3.42). The nanosystem (13 nm particle size) showed a radiochemical purity higher than 99% and stability in human serum. In vitro studies in HEP-G2 and PC-3 cancer cells (SR-BI positive) demonstrated that 225Ac was successfully internalized into the cytoplasm of cells, delivering high radiation doses to cell nuclei (107 Gy to PC-3 and 161 Gy to HEP-G2 nuclei at 24 h), resulting in a significant decrease in cell viability down to 3.22 ± 0.72% for the PC-3 and to 1.79 ± 0.23% for HEP-G2 at 192 h after 225Ac-rHDL treatment. After intratumoral 225Ac-rHDL administration in mice bearing HEP-G2 tumors, the biokinetic profile showed significant retention of radioactivity in the tumor masses (90.16 ± 2.52% of the injected activity), which generated ablative radiation doses (649 Gy/MBq). The results demonstrated adequate properties of rHDL as a stable carrier for selective deposition of 225Ac within cancer cells overexpressing SR-BI. The results obtained in this research justify further preclinical studies, designed to evaluate the therapeutic efficacy of the 225Ac-rHDL system for targeted alpha-particle therapy of tumors that overexpress the SR-BI receptor.

This research aimed to prepare 99mTc-/177Lu-CXCR4-L radiotracers and evaluate their in vitro and in vivo capability to detect the chemokine-4 receptor. Molecular docking calculations, Kd values ( 98.5%) estimated by saturation binding assays, as well as biodistribution studies in mice with induced tumors, confirmed the affinity of radiotracers towards CXCR4, expressed in DU-4475 breast cancer cells and C6 glioblastoma cells. Micro-SPECT/CT images showed that 99mTc-CXCR4-L and 177Lu-CXCR4-L could work as a theranostic pair for CXCR4 targets. Results warrant additional research to assess the therapeutic efficacy and dosimetry of 177Lu-CXCR4-L.

Beside partial coverage in three reviews so far (1994, 2009, 2019), there is no review on genotoxic studies dealing with mercury (Hg) and human exposure using the most usual genotoxic assays: sister chromatid exchanges (SCE), chromosomal aberrations (CA), cytochalasin B blocked micronucleus assay (CBMN), and single-cell gel electrophoresis (SCGE or alkaline comet assay). Fifty years from the first Hg genotoxicity study and with the Minamata Convention in force, the genotoxic potential of Hg and its derivatives is still controversial. Considering these antecedents, we present this first systematic literature overview of genotoxic studies dealing with Hg and human exposure that used the standard genotoxic assays. To date, there is not sufficient evidence for Hg human carcinogen classification, so the new data collections can be of great help. A review was made of the studies available (those published before the end of October 2021 on PubMed or Web of Science in English or Spanish language) in the scientific literature dealing with genotoxic assays and human sample exposure ex vivo, in vivo, and in vitro. Results from a total of 66 articles selected are presented. Organic (o)Hg compounds were more toxic than inorganic and/or elemental ones, without ruling out that all represent a risk. The most studied inorganic (i)Hg compounds in populations exposed accidentally, occupationally, or iatrogenically, and/or in human cells, were Hg chloride and Hg nitrate and of the organic compounds, were methylmercury, thimerosal, methylmercury chloride, phenylmercuric acetate, and methylmercury hydroxide.

The search for methods that identify early toxicity, induced by chemotherapy, is urgent. Changes in the biodistribution of radiopharmaceuticals could give information on early toxicity. Ten-week-old CD1 male mice were divided into four groups. Two groups were administered a weekly dose of 5 mg/kg of doxorubicin hydrochloride (DOX) for 5 weeks and the control groups were administered saline solution. One week after the end of treatment, the biodistribution of

Investigacion basada en el potencial bio-tecnologico de las micro-especies que habitan los cenotes de la Peninsula de Yucatan

Human tumors show intrinsic heterogeneity and changes in phenotype during disease progression, which implies different expression levels of cell surface receptors. The research on new heterodimeric lutetium-177 (Lu)-radiopharmaceuticals interacting with two different targets on tumor cells is a strategy for improvement of radiotheranostic performance. This study aimed to synthesize and characterize the Lu-DOTA-PSMA(inhibitor)-Lys-bombesin (Lu-DOTA-iPSMA-Lys-BN) heterodimer and to evaluate its potential to target prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRPr) overexpressed in prostate cancer.The heterodimeric conjugate was synthesized and characterized by infrarred, mass, and H-NMR spectroscopies. The ligand was labeled with Lu and the radiochemical purity was assessed by radio-high-performance liquid chromatography. PSMA/GRPr affinity and the heterobivalent effect on cell viability were evaluated in LNCaP and PC3 prostate cancer cell lines. The biodistribution profile (3 and 96 h) was assessed in athymic mice with induced prostate tumors. Using pulmonary LNCaP (PSMA-positive) and PC3 (GRPr-negative) micrometastasis models, the influence of heterobivalency and affinity on tumor uptake was quantified (micro-SPECT/CT).Lu-iPSMA-BN (radiochemical purity98%) showed specific recognition for PSMA and GRPr (IC50=5.62 and 3.49 nmol/l, respectively) with a significant decrease in cell viability (10.15% of cell viability in LNCaP and 40.10% in PC3 at 48 h), as well as high LNCaP and PC3 tumor uptake (5.21 and 3.21% ID/g at 96 h, respectively). Micro-SPECT/CT imaging showed the heterodimer ability to target the tumors (SUVmax of 1.93±0.30 and 1.76±0.10 in LNCaP and PC3, respectively), possibly influenced by the heterobivalent effect. Lu-DOTA-iPSMA-Lys-BN showed suitable affinity for PSMA and GRPr.The results warrant further preclinical studies to establish the Lu-radiotracer theranostic efficacy.

Despite the widespread use of nanotechnology in radio-imaging applications, lipoprotein based delivery systems have received only limited attention so far. These studies involve the synthesis of a novel hydrophobic radio-imaging tracer consisting of a hydrazinonicotinic acid (HYNIC)-N-dodecylamide and 99mTc conjugate that can be encapsulated into rHDL nanoparticles (NPs). These rHDL NPs can selectively target the Scavenger Receptor type B1 (SR-B1) that is overexpressed on most cancer cells due to excess demand for cholesterol for membrane biogenesis and thus can target tumors in vivo. We provide details of the tracer synthesis, characterization of the rHDL/tracer complex, in vitro uptake, stability studies and in vivo application of this new radio-imaging approach.

En el occidente del Estado de Mexico, la mitad de los ingresos hospitalarios por insuficiencia renal cronica (IRC) no asociada a diabetes mellitus ni a hipertension arterial corresponden a personas menores de 40 anos. Por lo tanto, esta IRC se considera de causas desconocidas (IRCd). En este trabajo se estudio la asociacion entre la presencia de metales y factores de riesgo para IRCd. Se realizo un estudio transversal analitico de 100 casos y 100 testigos. Se aplico un cuestionario para conocer las adicciones y exposiciones (alimentarias, ocupacionales y medicamentosas) de los sujetos. En 50 casos y 50 testigos se determino la concentracion de los metales arsenico, cadmio, mercurio y plomo en muestras de cabello. Finalmente, se construyo un mapa con la posicion de la vivienda de los 100 pacientes. Con base en una regresion logistica bivariada se determino que existe una asociacion estadisticamente significativa entre la IRCd y el consumo de tabaco, exposicion ocupacional a la construccion y herreria, y exposicion a arsenico. Es necesaria una muestra mayor para comprobar la exposicion ocupacional a la industria del papel, al consumo de paracetamol, naproxeno y cadmio. Los valores obtenidos en este trabajo para estas variables mencionadas son solo informativos. Los casos estudiados se localizan en la cuenca del Rio Lerma, uno de los mas contaminados del pais. La IRCd presente en el Estado de Mexico parece ser muy similar a la de Siri Lanka y la del Pacifico centroamericano, por lo que se requieren estudios a mayor escala.

Introduction: At the beginning of the 90´s the low number of medical physicists in Mexico was a concern. In 1994, the Instituto Nacional de Investigaciones Nucleares (ININ), sponsored by the International Atomic Energy Agency (IAEA), promoted the creation of a teaching and training program in Medical Physics. In 1996, the Universidad Autonoma del Estado de Mexico (UAEMex) and the ININ started the first formal Graduate Program in Science (Master's and Doctorate degree) specialized in Medical Physics in Mexico. Since 2009 the academic coordination of the program is under UAEMex supervision, but still ININ is its principal collaborator. The objective of this work is to present the professional and academic follow up of 100+ graduates of the UAEMex-ININ program after 24 years of experience. Methods: From the current student files, alumni records and the alumni tracking program, a retrospective analysis was carried out based on: a. Professional and social matters (geographical origin of the students, academic background, ratio of graduated students currently working as medical physicists and related areas, etc.); b. Academic impact (scientific publications and citations produced by the M.Sc. and D.Sc. programs, number of thesis by the study areas of the Medical Physics field, etc.). Results and discussion: The overall terminal efficiency of the program is 69.2%. Although the largest number of students comes from the State of Mexico and Mexico City, students have also been received from 12 other states of Mexico. The incoming students mostly have a Bachelor or Engineering degree majoring in physics. About 81.4% of the graduated work in areas related to medical physics, where 50% of that proportion are clinical medical physicists who are in 17 different states of the country. The areas of Nuclear Medicine and Radiation Therapy are the preferred ones for thesis, and the publications indicate the scientific impact of the program. Conclusions: The indicators presented in this work demonstrate that, in the last 24 years, the UAEMex-ININ M.Sc. and D.Sc. Medical Physics Graduate Program has achieved its goals, in forming clinical medical physicists and researchers. We are currently working to strengthen collaboration with the clinical sector, to impact in the national normativity, to support the establishment of clinical residency, to promote international collaboration and to lead our graduated to obtain recognized certifications in the medical physics areas.

Polymeric nanoparticles encompass micelles and dendrimers. They are used for improving or controlling the action of the loaded therapy or imaging agent, including radionuclides. Some radionuclides possess properties appropriate for simultaneous imaging and therapy of a disease and are therefore called theranostic. The diversity in core materials and surface modification, as well as radiolabeling strategies, offers multiples possibilities for preparing polymeric nanoparticles using radionuclides. The present review describes different strategies in the preparation of such nanoparticles and their applications in nuclear nanomedicine.

Reconstituted high-density lipoprotein (rHDL) nanoparticles are excellent transporters of molecules and very useful for targeted therapy as they specifically recognize the scavenger receptor, class B1 (SR-B1) that is present on the surface of a wide range of tumor cells. However, they have rarely been employed to transport photosensitizers (PS) for photodynamic therapy (PDT). Rhodamine (R) compounds have been dismissed as useful PSs for PDT due to their low 1O2 production, excitation wavelengths with little tissue penetration, and poor selectivity for tumor cells. It was recently demonstrated that when irradiating at 532 nm or with Cerenkov radiation (CR) from a β-emitting radionuclide, R123, R6G, and RB undergo electron transfer reactions (type I reaction) with folic acid. R6G also produces type I reactions with O2. In this work, the photodynamic effects of the rHDL-R system were evaluated in vitro. rHDL nanoparticles loaded with R123, R6G, and RB were synthesized, and the PS was internalized into T47D tumor cells. When cells were irradiated with a 532-nm laser in the presence of an rHDL-R systems, a cytotoxic photodynamic effect was obtained in the order R6G > R123 > RB. In the presence of CR from a 177Lu source, cytotoxicity showed the order R6G > RB > R123. The higher cytotoxicity induced by R6G in both cases corresponds to higher cellular internalization and larger production of type I and II reactions. Thus, in this work, it is proposed that rHDL-R/177Lu system can be applied in theragnostics as a multimodal radiotherapy-PDT-imaging system (imaging by SPECT or Cerenkov) and in hypoxic solid tumors in which external radiation is not effective and 177Lu-CR acts as light source.

Doxorubicin (DOX), an effective chemotherapeutic agent, has a wide excitation band centred at 480 nm. Cerenkov radiation (CR) is considered an internal light source in photodynamic therapy (PDT). DOX could be photoactivated by CR and thus, enhancing its cytotoxicity. In this work

Chronic pain is one of the most important causes of disability worldwide and represents a major public health challenge. The presence of inflammation is a common underlying mechanism of chronic pain. Nonsteroidal anti-inflammatory drugs (NSAIDs), COX2-selective and non-selective, showing analgesic and anti-inflammatory properties, are useful options for the treatment of chronic pain. Non-metabolized pharmaceutical products and their metabolites are excreted and enter sewage as biologically active substances. The accumulation of emerging pollutants, such as active pharmaceutical ingredients and their metabolites in the aquatic environment, has recently become a serious problem due to their bioaccumulation and ecotoxicity potential that affects living organisms. Pharmaceutical products considered as emerging pollutants are partially removed during the treatment of wastewater that contains them and are detected in groundwater, surface water, and wastewater effluent, as well as in drinking water at concentrations ranging from a few nanograms per liter to 15 μg/L. The elimination of these contaminants is essential due to the toxicity that causes in the organisms. Biological techniques that include microorganisms in their processes could be more effective for the elimination of pharmaceutical contaminants compared to the physicochemical techniques currently used.

This chapter discusses the main reasons for viewing non-steroidal anti-inflammatory drug (NSAIDs) as emerging contaminants. Their access routes into the environment are specified, in particular into natural and wastewater, and current evidence about their possible toxic effects is described. Mention is made of the most commonly used methods for routine determination from sampling to final quantification of NSAIDs in water samples of diverse origins. The most important aspects of sampling, extraction, and concentration, including microextraction methods, are detailed. The methods most commonly used in separation, identification, and quantification of NSAIDs in water are described. These methods include, in particular, gas and liquid chromatography systems and capillary electrophoresis that are coupled to different detectors. It was concluded that it is necessary to develop new methodologies that allow continuous monitoring at even lower costs than presently available.

This research aimed to evaluate the photothermal and radiotherapeutic effect of the 177Lu–Au-RGD-NLS-Aptamer anti-angiogenic nanosystem on the viability of U87MG cancer cells by using in vitro and in vivo models, as well as to assess the synergic effect of both therapies. In vitro results demonstrated a decrease in cell viability to 2.14 ± 0.27% after the treatment with photothermal therapy plus radiotherapy. These results correlated with the observed in vivo therapeutic response in mice with U87MG-induced tumors, in which 177Lu–Au-RGD-NLS-Aptamer under laser irradiation inhibited tumor progression. The combination of radiotherapy and thermotherapy in one nanoradiopharmaceutical could be potentially useful for cancer treatment.

Milk lipids were separated using a hexane:isopropanol mixture; then they were fractionated into apolar, medium polar and polar portions by SPE using a LC-Si column. The apolar fraction was further separated into 4 more portions depending on their polarity by another SPE method using a Florosil column. Levels of Cl, Br and I were measured by NAA. Halogens were detected in all separated fractions; but their highest levels were found in the most apolar fraction containing hydrocarbons which strongly indicates the presence of anthropogenic organohalogen compounds in milk. In addition, iodide and iodate ions in whole milk samples were measured.

This study aimed to synthesize a new 177Lu-iPSMA-RGD heterobivalent radiopharmaceutical, as well as to assess the in vitro radiopharmaceutical potential to target cancer cells overexpressing PSMA and α(v) β(3) integrins. The radiotracer prepared with a radiochemical purity of 98.8 ± 1.0% showed stability in human serum, specific recognition with suitable affinity to PSMA and α(v)β(3) integrins, and capability to inhibit cancer cell proliferation and VEGF signaling (antiangiogenic effect). Results warrant further preclinical studies to establish the 177Lu-iPSMA-RGD potential as a dual therapeutic radiopharmaceutical.

Mycobacteriumgenus causes a variety of zoonotic diseases. The best known example is the zoonotic tuberculosis due toM. bovis. Much less is known about “nontuberculous mycobacteria (NTM),” which are also associated with infections in humans. The Mexican standard NOM-ZOO-031-1995 regulates the presence ofM. bovisin cattle; however, no regulation exists for the NTM species. The objective of this study was to isolate and identify nontuberculous mycobacteria species from cattle of local herds in the south region of the State of Mexico through the identification and detection of the 100 bp molecular marker in the 23S rRNA gene with subsequent sequencing of the 16S rRNA gene. Milk samples (35) and nasal exudate samples (68) were collected. From the 108 strains isolated, 39 were selected for identification. Thirteen strains isolated from nasal exudates amplified the 100 bp molecular marker and were identified asM. neoaurum(six strains),M. parafortuitum(four strains),M. moriokaense(two strains), andM. confluentis(one strain). ExceptM. parafortuitum, the other species identified are of public health and veterinary concern because they are pathogenic to humans, especially those with underlying medical conditions.

Rhodamine (R) compounds are photosensitizers with low production of 1O2, so these compounds have not been considered very often for photodynamic therapy (PDT). Rhodamine-6G (R6G) undergoes electron transfer reactions with folic acid (FA). This reaction converts this form of R into a potential photosensitizer (PS) for PDT. The occurrence of this reaction with other R or oxygen has not yet been proven. The low penetrability of visible light into the skin has led to the proposal of a PDT light source alternative to Cerenkov radiation (CR). This work evaluates and compares the occurrence of type-I transfer reactions of R6G, R123, and RB with FA and oxygen when irradiated at 532 nm. The potential use of these compounds as type-I photosensitizers for PDT was also evaluated in vitro by excitation with CR. R electron transfer reactions with FA and oxygen were monitored by emission fluorescence and ultraviolet/visible (UV/Vis) absorption of 2,6-dichlorophenol-indophenol (DCPIP) as a redox indicator, respectively. 177Lu and 18F were used as CR sources. The results showed that the three R compounds underwent type-I transfer reactions with FA in the order R123 > R6G > RB when irradiated at 532 nm. Excitation of R6G using CR was demonstrated. Only R6G showed a type-I reaction with O2. By irradiating T47D tumor cells with a 532 nm laser light, cell death occurred in the order R6G>R123>RB. The same trend was found when cells were irradiated with CR. The possibility of using the type-I reaction between R compounds and biomolecules provides a new perspective in the use of these dyes in PDT.

The aim of this work was to synthesize Lys(1)(α,γ-Folate)-Lys(3)((177)Lu-DOTA)-Bombesin (1-14) ((177)Lu-Folate-BN), as well as to assess its potential for molecular imaging and targeted radiotherapy of breast tumors expressing folate receptors (FR) and gastrin-releasing peptide receptors (GRPR). Radiation absorbed doses of (177)Lu-Folate-BN (74 MBq, i.v.) estimated in athymic mice with T47D-induced breast tumors (positive to FR and GRPR), showed tumor doses of 23.9±2.1 Gy. T47D-tumors were clearly visible (Micro-SPECT/CT images). (177)Lu-Folate-BN demonstrated properties suitable as a theranostic radiopharmaceutical.

Gold nanoparticles conjugated to cyclo-[Arg-Gly-Asp-D-Phe-Lys(Cys)] peptides (AuNP-c[RGDfK(C)]) have been reported as systems with specific cell internalization in breast cancer cells. AuNPs have also been proposed as localized heat sources for cancer treatment using laser irradiation or radiofrequency (RF). The aim of this research was to analyze, based on the Mie theory, the AuNP-c[RGDfK(C)] absorption cross-sections (C(abs)) of low-frequency electromagnetic waves (13.56 MHz, λ = 22 m) and optical frequency waves (laser at λ = 532 nm) and to compare their effect on MCF7 cell viability as thermal conversion sources in AuNPs (20 nm) located inside cells. Cell viability was assessed in MCF7 cells treated with AuNP-c[RGDfK(C)] or water after exposure to the RF field (200 W, 100 V/cm) or laser irradiation (Irradiance 0.65 W/cm2). In both cases (RF and laser) the presence of nanoparticles in cells caused a significant increase in the temperature of the medium (RF: AT = 29.9 ± 1.7 degrees C for AuNP compared to ΔT = 13.0 ± 1.4 degrees C for water; laser: ΔT = 13.5 ± 0.7 degrees C for AuNP compared to 3.3 ± 0.5 degrees C for water). Although RF induced a higher increase in the temperature of the medium with nanoparticles, the largest effect on the cell viability was produced by laser when nanoparticles were located inside the cells (8.7?0.7% for laser compared to 19.4 ± 0.9% for RF). The differences obtained in C(abs) values (laser: 3.7 x 10- (16) m2; RF: 7.9 x 10-(23) m2) and the observed effect on MFC7 cell viability support two mechanisms previously proposed "wave energy absorption by AuNPs" when laser is used as a thermal conversion source, and "attenuation of the wave passing through the AuNP suspension" when RF is applied. The AuNP-c[RGDfK(C)] nanosystem shows suitable properties to improve hyperthermia treatments under laser irradiation due to a larger heat release inside cells.

Doxorubicin (DOX), an effective chemotherapeutic agent, has a wide excitation band centred at 480 nm. Cerenkov radiation (CR) is considered an internal light source in photodynamic therapy (PDT). DOX could be photoactivated by CR and thus, enhancing its cytotoxicity. In this work, 18F-FDG was used to evaluate the effect of Cerenkov radiation on DOX, in comparison to irradiation with a 450-nm laser beam, in terms of ROS production. The production of 1O2 and O2⁎- reactive species during DOX irradiation was detected indirectly by ABMA and DCPIP bleaching, respectively. The cytotoxic effect of the DOX / 18F-FDG CR system was evaluated in the T47D breast cancer cell line. The irradiation of DOX produced 1O2 and O2⁎- species using both 18F-FDG CR and a 450-nm laser beam. The majority reactive species produced in both cases was 1O2; a favourable result, given the greater cytotoxicity of this species. The viability of T47D cells in presence of DOX (5 nM), 18F-FDG (37.5 μCi) and DOX (5 nM)/18F-FDG (37.5 μCi) was (86 ± 9)%, (84 ± 8)% and (64 ± 5)%, respectively; these results suggest a synergistic cytotoxic effect derived from the cytotoxic activity of DOX and its photoactivation by 18F-FDG CR. It is worth noting that the system could be optimized in terms of DOX concentration and 18F-FDG activity for better results. Due to the fact that 18F-FDG is widely used in nuclear imaging, the DOX/18F-FDG system also possesses theragnostic characteristics. Thus, in this work, it is demonstrated that DOX can be used in a dual therapy system based on chemotherapy-PDT when 18F-FDG CR is used as a DOX excitation source.

Radiolabeled lipidic nanoparticles, particularly liposomes and lipoproteins, are of great interest as agents for imaging and therapy, due not only to their peculiar physicochemical and biological properties, but also to their great versatility and the ability to manipulate them to obtain the desired properties. This review provides an overview of radionuclide labeling strategies for preparing diagnostic and therapeutic nanoparticles based on liposomes and lipoproteins that have been developed to date, as well as the main quality control methods and in vivo applications.

Una opcion para biorremediar ambientes salinos contaminados con compuestos organicos hidrofobicos, es el uso de microorganismos haloalcalofilos o haloalcalotolerantes capaces de producir biosurfactantes estables y consumir al compuesto hidrofobo. El biosurfactante solubiliza al contaminante haciendolo biodisponible para el microrganismo. De estudios previos se conocia la capacidad de siete actinobacterias haloalcalotolerantes para transformar el antraceno. En este trabajo, a estas siete mas 11 mas aisladas de ambientes salinos, se les determino la capacidad para producir biosurfactantes con propiedades emulsificantes. A las que la mostraron, fueron seleccionadas para saber si utilizaban al antraceno como unica fuente de carbono y energia. La capacidad para producir biosurfactante fue determinada por los metodos de actividad hemolitica, gota colapsada y difusion del diametro de la gota. La propiedad emulsificante y la estabilidad de la emulsion se caracterizaron con el indice de emulsificacion y el indice de emulsificacion relativo, respectivamente. De 18 actinobacterias evaluadas, cinco cepas mostraron capacidad para producir biosurfactantes con propiedades emulsificantes, alta estabilidad en la emulsion y utilizacion de antraceno como unica fuente de carbono y energia. De estas cinco, dos son haloalcalofilas pertenecientes a la especie Nocardiopsis salina y tres son haloalcalotolerantes pertenecientes a las especies: Kocuria palustris, Microbacterium testaceum y Kocuria rosea. En un estudio previo se determino la capacidad transformadora de antraceno en las tres cepas haloalcalotolerantes, por lo tanto los resultados de este estudio sugieren proponerlas como candidatas para procesos de biorremediacion de ambientes salinos contaminados con compuestos hidrofobos. Asimismo se sugiere determinar la misma capacidad para las dos cepas haloalcalofilas.

Mie theory explains the interaction of light with a gold nanoparticle (AuNP) through the absorption (Cabs), scattering (Csca), and extinction (Cext) cross sections. These parameters have been calculated in the case of AuNPs dispersed in homogeneous media, but not for specific tissues. The aim of this research was to theoretically obtain the optical cross sections (Cabs, Csca, and Cext) of functionalized AuNPs in liver and colon tissues through Mie theory and correlate them with the temperature increase observed experimentally in tissues containing AuNPs under plasmonic photothermal irradiation using a Nd-YAG laser (λ = 532 nm). Calculations showed that Cabs represents 98.96±0.03% of Cext at 532 nm. The Cext value for a functionalized AuNP in water was 365.66 nm2 (94% of the theoretical maximum value at 522.5 nm), 404.24 nm2 in colon (98% of the theoretical maximum value at 525 nm), and 442.39 nm2 in liver (96% of the theoretical maximum value at 525 nm). Therefore, nanoparticles irradiated at 532 nm are very close to their resonance value. These results correlated with the experimental irradiation of functionalized AuNPs in different tissues, where the average temperature increase showed the pattern liver > colon > water. The temperature increase observed (ΔT up to 13°C) is sufficient to produce cellular death.

In this chapter, for articles addressing drugs as pollutants of natural and wastewater, we discuss the temporal distribution of studies, as well as the main countries of origin for such studies. Focus is given to those articles with more than 200 citations. The main sampling techniques, sample extraction, and detection methods accepted by the USEPA and USGS (based on LC-MS/MS and LC-MS) are reviewed, as well as those methods not based on MS, between 2014 and 2017. From this analysis, we propose directions for future research. Finally, a case study is presented that addresses the analysis of the surface waters of the Izucar de Matamoros region and the Atoyac River in Puebla, as well as the Zahuapan River in Tlaxcala, Mexico. By GC/MS, quantitative determination of naproxen, diclofenac, and triclosan, at stations on the Zahuapan (Tlaxcala), Atoyac, and Nexapa (Puebla) rivers, was performed during the period of 2012–2013. We found that 30% of the publications related with drugs as pollutants of natural and wastewater were published between 2014 and 2017. Spain has published the most of such articles (accounting for 25% of all publications). Three of the articles have more than 1,000 citations. HPLC/MS/MS was the most commonly used method, followed by GC/MS. However, less sophisticated detection alternatives were also used. GC/MS was used to demonstrate the presence of naproxen, diclofenac, triclosan, and carbamazepine in the Mexican Central Plateau and the inability of the wastewater treatment plants (WWTPs) to remove completely these contaminants.

Milk is known to contain organohalogen compounds. A mixture of hexane and isopropanol was used to extract lipids from bovine milk and neutron activation analysis (NAA) was employed to measure extractable organohalogens in the lipids. The samples were irradiated in a neutron flux of 2.5 × 1011 cm2 s−1 for 10 min, allowed to decay for 2 min, and counted for 10 min. Uncertainties associated with the preconcentration NAA measurements were investigated in detail. The mass fractions of halogens in mg kg−1 and their relative expanded uncertainties in percent in bovine milk lipids were: 32 (8.4 %), 2.65 (9.8 %) and 0.211 (6.6 %) for Cl, Br and I, respectively.

Radiosynovectomy is a technique used to decrease inflammation of the synovial tissue by intraarticular injection of a β-emitting radionuclide, such as 177Lu, which is suitable for radiotherapy due to its decay characteristics. Drug-encapsulating nanoparticles based on poly lactic‑co‑glycolic acid (PLGA) polymer are a suitable option to treat several arthritic diseases, used as anti-inflammatory drugs transporters of such as methotrexate (MTX), which has been widely used in the arthritis treatment (RA), and hyaluronic acid (HA), which specifically binds the CD44 and hyaluronan receptors overexpressed on the inflamed synovial tissue cells. The 1,4,7,10‑Tetraazacyclododecane‑1,4,7,10‑tetraacetic acid (DOTA) was used as complexing agent of Lutetium-177 for radiotherapy porpoises. The aim of this research was to synthesize 177Lu-DOTA-HA-PLGA(MTX) as a novel, smart drug delivery system with target-specific recognition, potentially useful in radiosynovectomy for local treatment of rheumatoid arthritis. The polymeric nanoparticle system was prepared and chemically characterized. The MTX encapsulation and radiolabelling were performed with suitable characteristics for its in vitro evaluation. The HA-PLGA(MTX) nanoparticle mean diameter was 167.6 nm ± 57.4 with a monomodal and narrow distribution. Spectroscopic techniques demonstrated the effective conjugation of HA and chelating agent DOTA to the polymeric nanosystem. The MTX encapsulation was 95.2% and the loading efficiency was 6%. The radiochemical purity was 96 ± 2%, determined by ITLC. Conclusion: 177Lu-DOTA-HA-PLGA(MTX) was prepared as a biocompatible polymeric PLGA nanoparticle conjugated to HA for specific targeting. The therapeutic nanosystem is based on bi-modal mechanisms using MTX as a disease-modifying antirheumatic drug (DMARD) and 177Lu as a radiotherapeutic component. The 177Lu-DOTA-HA-PLGA(MTX) nanoparticles showed properties suitable for radiosynovectomy and further specific targeted anti-rheumatic therapy.

Cerenkov radiation (CR) is the emission of UV-vis light generated by the de-excitation of the molecules in the medium, after being polarized by an excited particle traveling faster than the speed of light. When β particles travel through tissue with energies greater than 219 keV, CR occurs. Tissues possess a spectral optical window of 600 to 1100 nm. The CR within this range can be useful for quantitative preclinical studies using optical imaging and for the in-vivo evaluation of Lu177-radiopharmaceuticals (β-particle emitters). The objective of our research was to determine the experimental emission light spectrum of Lu177-CR and evaluate its transmission properties in tissue as well as the feasibility to applying CR imaging in the preclinical studies of Lu177-radiopharmaceuticals. The theoretical and experimental characterizations of the emission and transmission spectra of Lu177-CR in tissue, in the vis-NIR region (350 to 900 nm), were performed using Monte Carlo simulation and UV-vis spectroscopy. Mice Lu177-CR images were acquired using a charge-coupled detector camera and were quantitatively analyzed. The results demonstrated good agreement between the theoretical and the experimental Lu177-CR emission spectra. Preclinical CR imaging demonstrated that the biokinetics of Lu177-radiopharmaceuticals in the main organs of mice can be acquired.

Radiolabeled gold nanoparticles may function simultaneously as radiotherapy and thermal ablation systems. The gastrin-releasing peptide receptor (GRP-r) is overexpressed in prostate cancer, and Lys(3) -bombesin is a peptide that binds with high affinity to the GRP-r. HIV Tat(49-57) is a cell-penetrating peptide that reaches the DNA. In cancer cells, (177) Lu shows efficient crossfire effect, whereas (99m) Tc that is internalized in the cancer cell nuclei acts as an effective system of targeted radiotherapy because of the biological Auger effect. The aim of this research was to evaluate the in vitro potential of (99m) Tc-labeled and (177) Lu-labeled gold nanoparticles conjugated to Tat(49-57)-Lys(3) -bombesin peptides ((99m) Tc/(177) Lu-AuNP-Tat-BN) as a plasmonic photothermal therapy and targeted radiotherapy system in PC3 prostate cancer cells. Peptides were conjugated to AuNPs (5 nm) by spontaneous reaction with the thiol group of cysteine (Cys). The effect on PC3 cell viability after laser heating of the AuNP-Tat-BN incubated with the cancer cells was conducted using an Nd:YAG laser pulsed for 5 ns at 532 nm (0.65 W/cm(2) ). For the (99m) Tc/(177) Lu-AuNP-Tat-BN to be obtained, the (177) Lu-DOTA-Gly-Gly-Cys and (99m) Tc-HYNIC-octreotide radiopeptides were first prepared and added simultaneously to a solution of AuNP-Tat-BN. (99m) Tc/(177) Lu-AuNP-Tat-BN (20 Bq/cell) was incubated with PC3 cells, and the effect on the cell proliferation was evaluated after 3 days. Fluorescence images of (99m) Tc/(177) Lu-AuNP-Tat-BN internalized in nuclei of PC3 were also obtained. After laser irradiation, the presence of AuNP-Tat-BN caused a significant increase in the temperature of the medium (46.4 vs 39.5 °C of that without AuNP) resulting in a significant decrease in PC3 cell viability down to 1.3%. After treatment with (99m) Tc/(177) Lu-AuNP-Tat-BN, the PC3 cell proliferation was inhibited. The nanosystem exhibited properties suitable for plasmonic photothermal therapy and targeted radiotherapy in the treatment of prostate cancer.

The use of native strains of microorganisms from soils is an excellent option for bioremediation. To our knowledge, until now there has been no other group working on the isolation of Actinobacteria from contaminated soils in Mexico. In this study, samples of soils close to areas with oil activity in the State of Veracruz, Mexico, were inoculated for the isolation of Actinobacteria. The strains isolated were characterized morphologically, and the concentrations of NaCl and pH were determined for optimal growth. Strain selection was performed by the detection of a phylogenetic marker for Actinobacteria located at the 23S rRNA gene, followed by species identification by sequencing the 16S rRNA gene. Several haloalkalitolerant Actinobacteria were isolated and identified as: Kocuria rosea, K. palustris, Microbacterium testaceum, Nocardia farcinica and Cellulomonas denverensis. Except for C. denverensis, the biomass of all strains increased in the presence of anthracene. The strains capacity to metabolize anthracene (at 48 h), determined by fluorescence emission, was in the range of 46-54%. During this time, dihydroxy aromatic compounds formed, characterized by attenuated total reflectance Fourier transform infrared spectroscopy bands of 1205 cm-1 and 1217 cm-1. Those Actinobacteria are potentially useful for the bioremediation of saline and alkaline environments contaminated with polycyclic aromatic hydrocarbon compounds. [Int Microbiol 2016; 19(1):15-26].