Nanoparticles (NPs) coated with hyaluronic acid (HA) seem to be increasingly promising for targeted therapy due to HA chemical versatility, which allows them to bind drugs of different natures, and ...their affinity with the transmembrane receptor CD-44, overexpressed in tumor cells. However, an essential aspect for clinical use of NPs is formulation stability over time. For these reasons, analytical techniques capable of characterizing their physico-chemical properties are needed. In this work, poly(lactide-co-glycolide) (PLGA) NPs with an average diameter of 100-150 nm, coated with a few 10 s of nm of HA, were synthesized. For stability characterization, two complementary investigative techniques were used: Dynamic Light Scattering (DLS) and Surface-Enhanced Raman Scattering (SERS) spectroscopy. The first technique provided information on size, polidispersity index, and zeta-potential, and the second provided a deeper insight on the NP surface chemicals, allowing distinguishing of HA-coated NPs from uncoated ones. Furthermore, in order to estimate formulation stability over time, NPs were measured and monitored for two weeks. SERS results showed a progressive decrease in the signal associated with HA, which, however, is not detectable by the DLS measurements.
The structural and mechanical properties of the microenvironmental context have a profound impact on cancer cell motility, tumor invasion, and metastasis formation. In fact, cells react to their ...mechanical environment modulating their adhesion, cytoskeleton organization, changes of shape, and, consequently, the dynamics of their motility. In order to elucidate the role of extracellular matrix stiffness as a driving force in cancer cell motility/invasion and the effects of ionizing radiations on these processes, we evaluated adhesion and migration as biophysical properties of two different mammary cell lines, over a range of pathophysiological stiffness (1-13 kPa) in a control condition and after the exposure to two different X-ray doses (2 and 10 Gy, photon beams). We concluded that the microenvironment mimicking the normal mechanics of healthy tissue has a radioprotective role on both cell lines, preventing cell motility and invasion. Supraphysiological extracellular matrix stiffness promoted tumor cell motility instead, but also had a normalizing effect on the response to radiation of tumor cells, lowering their migratory capability. This work lays the foundation for exploiting the extracellular matrix-mediated mechanism underlying the response of healthy and tumor cells to radiation treatments and opens new frontiers in the diagnostic and therapeutic use of radiotherapy.
In this paper, an in-depth and systematic study of the radiological characterization of three types of Puglia region natural limestones (Pietra Leccese, Pietra Mazzara and Carparo) was carried out. ...The investigation was performed by XRF spectroscopy for a chemical analysis, and gamma spectroscopy of the specific activity concentration of natural radionuclides 226Ra, 232Th, and 40K. Although the limestone does not fall within the category included by Italian Legislative Decree 101/2020, the gamma index was calculated using the results of the gamma spectroscopy measurements. For Pietra Mazzara and Carparo stones, the gamma index was found to be less than the reference value; conversely Pietra Leccese was found to be higher. To obtain a more complete evaluation of the external exposure, radium equivalent activity and external radiation hazard were calculated for all analyzed stones. The results suggest the need to broadly consider the radiological risk for these stones, and for limestone more generally, when used as a building material.
Neutron induced reactions on stable and unstable nuclei play a significant role in the nucleosynthesis of the elements in the cosmos. In the last years, several efforts have been made to investigate ...the possibility of applying the Trojan Horse Method (THM) to neutron induced reactions mostly by using deuteron as “TH-nucleus”. Here, the main advantages of using THM will be given together with a more focused discussion on the recent
7
Be(n,
α
)
4
He and the
14
N(n,p)
14
C reactions.
Rn gas represents the major contributor to human health risk from environmental radiological exposure. In confined spaces radon can accumulate to relatively high levels so that mitigation actions are ...necessary. The Italian legislation on radiation protection has set a reference value for the activity concentration of radon at 300 Bq/m
. In this study, measurements of the annual radon concentration of 62 bank buildings spread throughout the Campania region (Southern Italy) were carried out. Using devices based on CR-39 solid-state nuclear track detectors, the
Rn level was assessed in 136 confined spaces (127 at underground floors and 9 at ground floors) frequented by workers and/or the public. The survey parameters considered in the analysis of the results were: floor types, wall cladding materials, number of openings, door/window opening duration for air exchange. Radon levels were found to be between 17 and 680 Bq/m
, with an average value of 130 Bq/m
and a standard deviation of 120 Bq/m
. About 7% of the results gave a radon activity concentration above 300 Bq/m
. The analysis showed that the floor level and air exchange have the most significant influence. This study highlighted the importance of the assessment of indoor radon levels for work environments in particular, to protect the workers and public from radon-induced health effects.
The lockdown restrictions, as a first solution to contain the spread of the COVID-19 pandemic, have affected everyone's life and habits, including the time spent at home. The latter factor has drawn ...attention to indoor air quality and the impact on human health, particularly for chemical pollutants. This study investigated how the increasing time indoor influenced exposure to natural radioactive substances, such as radon gas. To calculate the radiological risk, we considered the most consolidated indices used for radiation protection: annual effective dose, excess lifetime cancer risk, and the lung cancer case. Furthermore, two different exposure times were considered: pre-lockdown and post-lockdown. The lockdown increased the indoor exposure time by 4% and, consequently, the radiological risk factors by 9%. Furthermore, the reference value of 300 Bq/m
, considered acceptable for human radiation protection, may need to be lowered further in the case of conditions similar to those of the lockdown period.
The physical–chemical properties of water are closely linked to the geological nature of the site where they are located. This aspect becomes even more interesting when analyzing the natural ...radionuclides in the drinking water of a volcanic territory such as Campania in southern Italy. This study concerned the measurement of activity concentration of gross alpha and beta, radon, and tritium to evaluate their biological impact. The measurements were carried out using alpha spectrometry for alpha emitters, proportional counter for beta emitters, the electret system for radon in water, and finally liquid scintillation for the measurement of tritium concentration. The biological impact was assessed considering the indicative dose, if applicable, and the effective annual dose of radon. Although the results show that the values are below international and national references, the radiological characterization of drinking water is of fundamental importance to optimize the radiation protection of the population.
ASSESSMENT OF RADON KNOWLEDGE IN NEAPOLITAN AREA D'Avino, Vittoria; La Verde, Giuseppe; Coppola, Fulvio ...
Fresenius environmental bulletin,
12/2020, Letnik:
29, Številka:
12A
Journal Article
Recenzirano
Indoor radon exposure is the second most important risk factor for lung cancer incidence on human. The purpose of this study was to assess the status of the knowledge of radon gas in the general ...population and high school students, in the metropolitan area of Naples. A survey was planned in order to obtain data on both public knowledge of radon gas and its health effects. The results on 6705 collected questionnaires showed that a similar percentage of respondents asserted to know radon gas, 31% and 38% in general and student population, respectively. This study demonstrate that actual educational programs have to be enhanced in order to provide the spread of the radon knowledge and the awareness of the exposure risk.
The microenvironment of breast cancer actively participates in tumorigenesis and cancer progression. The changes observed in the architecture of the extracellular matrix initiate an oncogene-mediated ...cell reprogramming, that leads to a massive triggering of YAP nuclear entry, and, therefore, to cancer cell proliferation, invasion and probably to increased radiation-resistance. However, it is not yet fully understood how radiotherapy regulates the expression and subcellular localization of YAP in breast cancer cells experiencing different microenvironmental stiffnesses. To elucidate the role of extracellular matrix stiffness and ionizing radiations on YAP regulation, we explored the behaviour of two different mammary cell lines, a normal epithelial cell line (MCF10A) and a highly aggressive and invasive adenocarcinoma cell line (MDA-MB-231) interacting with polyacrylamide substrates mimicking the mechanics of both normal and tumour tissues (∼1 and ∼13 kPa). We report that X-ray radiation affected in a significant way the levels of YAP expression, density, and localization in both cell lines. After 24 h, MCF10A and MDA-MB-231 increased the expression level of YAP in both nucleus and cytoplasm in a dose dependent manner and particularly on the stiffer substrates. After 72 h, MCF10A reduced mostly the YAP expression in the cytoplasm, whereas it remained high in the nucleus of cells on stiffer substrates. Tumour cells continued to exhibit higher levels of YAP expression, especially in the cytoplasmic compartment, as indicated by the reduction of nuclear/cytoplasmic ratio of total YAP. Then, we investigated the existence of a correlation between YAP localization and the expression of the nuclear envelope protein lamin A/C, considering its key role in modulating nuclear deformability and changes in YAP shuttling phenomena. As supposed, we found that the effects of radiation on YAP nucleus/cytoplasmic expression ratio, increasing in healthy cells and decreasing in tumour ones, were accompanied by lower and higher lamin A/C levels in MCF10A and MDA-MB-231 cells, respectively. These findings point to obtain a deeper knowledge of the role of the extracellular matrix and the effects of X-rays on YAP and lamin A/C expression that can be used in the design of doses and timing of radiation therapy.
Abstract
Tuscany, with its mixed geology, offers a great variety of stones that are used to build entire villages. In this paper, two of these building materials are considered:
Rosso Ammonitco
and
...Pietra Serena.
In particular, the activity concentration of
226
Ra,
232
Th and
40
K have been analysed in order to estimate the value of the gamma index. In addition to this, the X-ray fluorescence spectroscopy has been carried out to obtain a chemical characterization of the stones. Although these kind of stones are not subjected to radiological characterization, the approach used was the one reported in Radiation Protection 112, also implemented in the Italian Legislative Decree 101/2020, because of their lithographical peculiarity and their employment in construction.
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