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For a while, gold nanoparticles (AuNPs) have been recognized as potential radiosensitizers in cancer radiation therapy, mainly due to their physical properties, making them appealing for medical applications. Nevertheless, the performance of AuNPs as radiosensitizers still raises important questions that need further investigation. Searching for selective prostate (PCa) radiosensitizing agents, we studied the radiosensitization capability of the target-specific AuNP-BBN in cancer versus non-cancerous prostate cells, including the evaluation of dose rate effects in comparison with non-targeted counterparts (AuNP-TDOTA). PCa cells were found to exhibit increased AuNP uptake when compared to non-tumoral ones, leading to a significant loss of cellular proliferation ability and complex DNA damage, evidenced by the occurrence of multiple micronucleus per binucleated cell, in the case of PC3 cells irradiated with 2 Gy of γ-rays, after incubation with AuNP-BBN. Remarkably, the treatment of the PC3 cells with AuNP-BBN led to a much stronger influence of the dose rate on the cellular survival upon γ-photon irradiation, as well as on their genomic instability. Overall, AuNP-BBN emerged in this study as a very promising nanotool for the efficient and selective radiosensitization of human prostate cancer PC3 cells, therefore deserving further preclinical evaluation in adequate animal models for prostate cancer radiotherapy.

The current study investigates the venom-delivery system of green and red morphotypes of the sea anemone Actinia equina to disclose its potential as a source of bioactive compounds. We compared the two morphotypes using electron and optical microscopy, proteomics, and toxicity assessment on zebrafish embryos. Specialized venom-injecting cells (nematocysts) are equally distributed and found in the tentacles of both varieties. Proteomics revealed proteins of interest in both red and green Actinia, yielding the three most abundant Gene Ontology (GO) terms related to the biological processes “proteolysis”, “hemolysis in another organism” and “lipid catabolic process”. Neurotoxins and cytolytic toxins similar to known cnidarian toxins like PsTX-60A and AvTX-60A, for instance, were identified in both types. Extracts from green and red anemones were toxic to zebrafish embryos, with green anemone venom appearing to be more potent. The findings highlight the presence of proteinaceous toxins in A. equina and the potential for different varieties to possess distinct bioactive compounds. Notably, pore-forming toxins are suggested for molecular probes and immunotoxins, making them valuable assets for potential biotechnological and biomedical purposes.

As Yondelis joins the ranks of approved anti-cancer drugs, the benefit from exploring the oceans’ biodiversity becomes clear. From marine toxins, relevant bioproducts can be obtained due to their potential to interfere with specific pathways. We explored the cytotoxicity of toxin-bearing secretions of the polychaete Eulalia onto a battery of normal and cancer human cell lines and discovered that the cocktail of proteins is more toxic towards an ovarian cancer cell line (A2780). The secretions’ main proteins were identified by proteomics and transcriptomics: 14-3-3 protein, Hsp70, Rab3, Arylsulfatase B and serine protease, the latter two being known toxins. This mixture of toxins induces cell-cycle arrest at G2/M phase after 3h exposure in A2780 cells and extrinsic programmed cell death. These findings indicate that partial re-activation of the G2/M checkpoint, which is inactivated in many cancer cells, can be partly reversed by the toxic mixture. Protein–protein interaction networks partake in two cytotoxic effects: cell-cycle arrest with a link to RAB3C and RAF1; and lytic activity of arylsulfatases. The discovery of both mechanisms indicates that venomous mixtures may affect proliferating cells in a specific manner, highlighting the cocktails’ potential in the fine-tuning of anti-cancer therapeutics targeting cell cycle and protein homeostasis.

Background: Ferrabis(dicarbollide) ([o-FESAN]−) in combination with proton–boron fusion therapy (PBFT) or boron neutron capture therapy (BNCT) are promising alternative radiation modalities for the treatment of breast cancer. The aim of this study was to explore the underlying effects of [o-FESAN]− radio enhancement on breast cancer cells in vitro and in vivo, and to perform comparative dosimetry calculations. Methods: The cellular effects on SKBR-3 and MDA-MB-231 breast cancer cells and MDA-MB-231 xenograft-bearing nude mice induced by carrier-free [o-FESAN]− after BNCT or PBFT were evaluated following recommended protocols. Monte Carlo (MC) dosimetry calculations were performed at the cellular scale for both radiation modalities. Results: Selective retention of [o-FESAN]− within the cytoplasm and nucleus of SKBR-3 and MDA-MB-231 breast cancer cells is demonstrated. Moreover, in vivo studies with MDA-MB-231 xenograft-bearing nude mice show appreciable accumulation of [o-FESAN]− in the tumor. Both radiation modalities induce loss of cellular viability and survival. Comparative dosimetry studies between proton and neutron irradiation agree with the viability data, showing a good correlation between absorbed dose vs. cellular effects. In the case of PBFT, cell structural changes are likely due to necrosis caused by the production of reactive oxygen species (ROS). To explain the radio enhancement effects in more detail, other mechanisms should be taken into consideration. Conclusions: Our results validate the effectiveness of both PBFT and BNCT therapeutic modalities, warranting further studies on carrier-free [o-FESAN]− as a candidate drug for potential clinical translation of radio enhancers in binary radiation therapies.

Background: Radiosensitizers can be used to enhance tumor response and mitigate toxicity in healthy tissues during radiation therapy. This study investigates the radiosensitizing potential of the metallacarborane Fe/57Fe-ferrabisdicarbollide in SK-BR-3 and MDA-MB-231 breast cancer cells, using two distinct gamma-photon sources: high-dose 60Co (2.08 Gy) and low-dose 57Co (37.55 mGy, 57Fe Mössbauer effect). Methods: We evaluated cell viability and survival in 2D monolayer and 3D spheroid cultures, as well as the mechanism of cell death (ROS production, apoptosis or necrosis). Computational dosimetry was used to calculate the average absorbed dose. Results: In 2D models, both radiation sources induced reduced viability and increased ROS, with distinct cell death patterns dependent on the source (apoptosis or necrosis). Comparing 2D and 3D MDA-MB-231 models revealed that spheroid survival was significantly more impaired. The low-dose 57Co source caused a significant radiosensitization in MDA-MB-231 spheroids, dramatically impacting viability and survival. This effect is attributed to the Mössbauer effect, where the resonant absorption of 14.41 keV radiation by 57Fe leads to a massive, localized dose enhancement. The subsequent cascade of Auger and conversion electrons (local high LET) caused significantly greater cellular damage than sparse photon radiation. Conclusions: Fe/57Fe-ferrabisdicarbollide demonstrates a potent radiosensitizing effect depending on the cell model and the radiation source used. Crucially, the observed radiosensitization allows for the development of a new, more efficient cancer radiotherapy approach that can achieve therapeutic efficacy using a significantly lower radiation dose to the patient. This paves the way for safer and better-tolerated cancer treatments.

Dental implants are the preferred fixed oral rehabilitation for replacing lost teeth. When peri-implant tissues become inflamed, the removal of plaque accumulating around the implant becomes imperative. Recently, several new strategies have been developed for this purpose, with electrolytic decontamination showing increased potential compared to traditional mechanical strategies. In this in vitro pilot study, we compare the efficacy of an electrolytic decontaminant (Galvosurge®) with an erythritol jet system (PerioFlow®) and two titanium brushes (R-Brush™ and i-Brush™) in removing Pseudomonas aeruginosa PAO1 biofilms from implants. Changes in the implant surface after each approach were also evaluated. Twenty titanium SLA implants were inoculated with P. aeruginosa and then randomly assigned to each treatment group. After treatment, decontamination efficacy was assessed by quantifying colony-forming units (log10 CFU/cm2) from each implant surface. Scanning electron microscopy was used to analyse changes in the implant surface. With the exception of R-Brush, all treatment strategies were similarly effective in removing P. aeruginosa from implants. Major surface changes were observed only in implants treated with titanium brushes. In conclusion, this pilot study suggests that electrolytic decontamination, erythritol-chlorhexidine particle jet system and i-Brush™ brushing have similar performance in removing P. aeruginosa biofilm from dental implants. Further studies are needed to evaluate the removal of more complex biofilms. Titanium brushes caused significant changes to the implant surface, the effects of which need to be evaluated.

Cephalopods like octopuses and cuttlefishes are known to secrete a ‘toxic saliva’ to inject into their prey, especially crustaceans since the XIX century. However, only in the mid-XX century were the first coleoid-specific toxins successfully isolated. Motivated by the growing interest on the global ocean as an almost inexhaustible source of novel bioactive compounds, we used RNA-Seq – based transcriptomics and de novo assembly of transcriptomes to screen the posterior salivary glands of Sepia officinalis (the common cuttlefish) from the Portuguese West coast for toxins and other bioactive proteins and peptides. Supported by microanatomical analyses, the posterior salivary glands constitute indeed the ‘venom gland’ whereas the more elusive anterior salivary glands (embedded in the buccal mass) are responsible for the production of mucin-rich saliva that is effectively the vehicle that transports the toxins as the venom is injected into the prey. Indeed, the transcriptomic profiling suggests that the cuttlefish venom is complex mixture of bioactive proteins, among which neurotoxins are major players, together with enzymes whose function is to digest the extracellular matrix to facilitate diffusion of the toxins. Nonetheless, by comparing with previous RNA-Seq data obtained from S. officinalis collected from other biogeographical areas, it may be suggested that significant inter-populational variation in venom composition can occur, which may potentially increase the span of bioactives secreted by these animals. We isolated and validated the full coding sequences for three important toxins, a cysteine-rich venom protein (CRVP), a venom insulin (VIns) and a cephalotoxin (CTX). The toxins seem to be relatively conserved among coleoids but diverging from other venomous mollusks such as cone snails. Their properties as potent modulators of glucose (in the case of VIns) and as potential neurotoxins (like CRVP and CTX) can render them primer targets for drug development.

Gold(III) bisdithiolate complexes have been reported as potential antimicrobial and antitumoral agents. The complex [Au(cdc)2]− (cdc=cyanodithioimido carbonate) displayed antimicrobial and outstanding antitumor activity against the ovarian cancer cells A2780 and A2780cisR, which are sensitive and resistant to cisplatin, respectively. However, poor water solubility may hamper its clinical use. Block copolymer micelles (BCMs) may solubilize hydrophobic drugs, improving their bioavailability and circulation time in blood. Aiming to provide water solubility, prolonged availability, and enhanced therapeutic indexes, BCMs loaded with [Au(cdc)2]− were synthesized and characterized. The BCM-[Au(cdc)2] micelles were prepared with a loading efficiency of 64.6% and a loading content of 35.3 mg [Au(cdc)2]−/gBCM. A hydrodynamic diameter of 77.31 ± 27.00 nm and a low polydispersity index of 0.18 indicated that the micelles were homogenous and good candidates for drug delivery. Cytotoxic activity studies against A2780/A2780cisR cells showed that BCM-[Au(cdc)2] maintained relevant cytotoxic activity comparable to the cytotoxicity observed for the same concentration of gold complexes. The Au uptake in A2780 cells, determined by PIXE, was ca. 17% higher for BCMs-[Au(cdc)2] compared to [Au(cdc)2]−. The BCMs-[Au(cdc)2] presented antimicrobial activity against S. aureus Newman and C. glabrata CBS138. These results evidenced the potential of BCM-[Au(cdc)2] for drug delivery and its promising anticancer and antimicrobial activities.

The fraction of organic matter present affects the fragmentation behavior of sialoliths; thus, pretherapeutic information on the degree of mineralization is relevant for a correct selection of lithotripsy procedures. This work proposes a methodology for in vivo characterization of salivary calculi in the pretherapeutic context. Sialoliths were characterized in detail by X-ray computed microtomography (μCT) in combination with atomic emission spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Correlative analysis of the same specimens was performed by in vivo and ex vivo helical computed tomography (HCT) and ex vivo μCT. The mineral matter in the sialoliths consisted essentially of apatite (89 vol%) and whitlockite (11 vol%) with average density of 1.8 g/cm3. In hydrated conditions, the mineral mass prevailed with 53 ± 13 wt%, whereas the organic matter, with a density of 1.2 g/cm3, occupied 65 ± 10% of the sialoliths’ volume. A quantitative relation between sialoliths mineral density and X-ray attenuation is proposed for both HCT and μCT.

Objective To quantitatively compare the extent of enhancement of abdominal structures on MRI in an intraindividual fashion at 1.5 and 3 T. Methods HIPAA-compliant, retrospective, longitudinal, intraindividual, crossover study, with waived informed consent, of consecutive individuals scanned at both 1.5 and 3 T closed-bore magnets using gadobenate dimeglumine during different phases of enhancement at tightly controlled arterial phase timing. Quantitative ROI measurements and qualitative sub-phase arterial phase assignments were independently performed by two radiologists. Qualitative discrepancies were resolved by a senior radiologist. Results Final population included 60 patients [41 female and 19 male; age, 49.35 ± 18.31 years (range 16–81); weight, 78.88 ± 20.3 kg (range 44.5–136)]. Similar enhancement peak patterns were noted at both field strengths. Interobserver agreement of quantitative evaluations was substantial. Significantly higher amplitudes of enhancement peaks were noted for all abdominal solid organs during all phases at 3 T, except for the pancreas ( p  = 0.17–0.30). Significantly higher amplitudes of enhancement peaks of the abdominal aorta at 1.5 T were noted. Conclusion Similar peak patterns of enhancement for abdominal structures were observed at 1.5 and 3 T, with solid abdominal organs showing a higher percentage enhancement at 3 T, while unexpectedly higher aortic higher percentage enhancement was observed at 1.5 T. Key Points • Similar enhancement peak patterns at both field strengths for studied abdominal structures. • Significantly higher percentage enhancement of most abdominal organs at 3 T. • Non-statistically significant trend of higher pancreatic percentage enhancement at 3 T. • Significantly lower abdominal aortic percentage enhancement at 3 T.