Eco-friendly extraction of Mastocarpus stellatus carrageenan for the synthesis of gold nanoparticles with improved biological activity.

Carrageenan was extracted from Mastocarpus stellatus using hot water extraction under atmospheric and pressurized conditions. The influence of heating temperature during a non-isothermal heating profile up to temperatures in the range 70-190 °C was studied to evaluate the extraction yields and properties of the carrageenan fraction. Under the selected conditions (130 °C), extracted carrageenan (CMs) was used for the green synthesis of gold nanoparticles (AuNPs). After the optimization of the reaction conditions, the synthesized gold nanoparticles (Au@CMs) were characterized by UV-Vis spectroscopy, Z potential measurements, electron microscopy, and X-ray diffraction analysis, which confirmed the formation of spherical, polycrystalline, and negatively charged nanoparticles with a mean diameter of 14.3 ± 2.1 nm. The study conducted by scanning transmission electron microscopy, energy dispersive X-ray analysis and mapping confirmed the presence of carrageenan stabilizing AuNPs. Finally, Fourier transformed infrared spectroscopy was performed to analyze the functional groups of CMs involved in the reduction and stabilization of AuNPs. The selective cytotoxicity and the antioxidant activity of the Au@CMs were evaluated in different cell lines and compared to the CMs. Au@CMs showed an improved antioxidant capacity in cells under oxidative stress and the induction of apoptosis in a monocytic cell line, while no antitumor effect was observed in a lung endothelial cell line.

Saccorhiza polyschides used to synthesize gold and silver nanoparticles with enhanced antiproliferative and immunostimulant activity.

Over the last years, there has been an increasing trend towards the use of environmentally friendly processes to synthesize nanomaterials. In the case of nanomedicine, the use of bionanofactories with associated biological properties, such as seaweed, has emerged as a promising field of work due to the possibility they open for both the preservation of those properties in the nanomaterials synthesized and/or the reduction of their toxicity. In the present study, gold (Au@SP) and silver (Ag@SP) nanoparticles were synthesized using an aqueous extract of Saccorhiza polyschides (SP). Several techniques showed that the nanoparticles formed were spherical and stable, with mean diameters of 14 ± 2 nm for Au@SP and 15 ± 3 nm for Ag@SP. The composition of the biomolecules in the extract and the nanoparticles were also analyzed. The analyses performed indicate that the extract acts as a protective medium, with the particles embedded in it preventing aggregation and coalescence. Au@SP and Ag@SP showed superior immunostimulant and antiproliferative activity on immune and tumor cells, respectively, to that of the SP extract. Moreover, the nanoparticles were able to modulate the release of reactive oxygen species depending on the concentration. Hence, both nanoparticles have a significant therapeutic potential for the treatment of cancer or in immunostimulant therapy.

XAP-Lab: A software tool for designing flexible X-ray acquisition protocols.

BACKGROUND AND OBJECTIVE: The availability of digital X-ray detectors, together with the development of new robotized hardware and reconstruction algorithms, opens the opportunity to provide 3D capabilities with conventional radiology systems. This would be based on the acquisition of a limited number of projections with non-standard geometrical configurations. The versatility of these techniques is enormous, enabling the introduction of tomography in situations where a CT system is hardly available, such as during surgery or in an ICU, or in which a reduction of radiation dose is key, as in pediatrics. Computer simulations are a valuable tool to explore these possibilities before their actual implementation on real systems. Existing software tools generally simulate only standard acquisition protocols, such as cone-beam with circular trajectory, thus not allowing the users to evaluate more sophisticated projection geometries. The goal of this work is to design a simulation tool that enables the design of acquisition protocols with flexible projection geometries. METHODS: We present XAP-Lab, a software tool for the design of X-ray acquisition protocols with flexible trajectories. For a given projection geometry, defined through a graphical user interface, it allows the user to simulate projections using GPU-accelerated kernels, the visualization of the scanned field of view and the estimation of the total radiation dose. The complete acquisition protocol can then be exported with the appropriate format for its use on real systems. We tested the software by optimizing a tomosynthesis protocol and validating the results with real acquisitions using a SEDECAL NOVA FA radiography system and phantoms for quantitative and qualitative evaluation. RESULTS: Quantitative evaluation using a phantom showed a mean error under 4 mm for each position, below the ±5 mm tolerance of the system specified by the manufacturer. Visual evaluation on a thorax acquisition also showed a good geometrical agreement between simulated and real projections. CONCLUSIONS: Results showed an excellent matching with simulations, supporting the usefulness of XAP-Lab for the design of new acquisition protocols with non-standard geometries.

Use of small intestinal submucosa for corporal body grafting in cases of epispadias and epispadias/exstrophy complex.

BACKGROUND: Male epispadias is a rare congenital urogenital anomaly in which the meatus is ectopically located along the dorsal midline of the penile shaft. In cases associated with severe curvature, functional and cosmetic outcomes could be accomplished by lengthening the shorter dorsal surface with the use of corporal grafting. Various graft materials have been used in the past for hypospadias repair including tunica vaginalis, dermis, and small intestinal submucosa (SIS). The use of SIS grafting for corporoplasty during epispadias repair has rarely been described in the literature. OBJECTIVE: To report the experience in the management of dorsal corporal body grafting using SIS in children with severe penile curvature due to epispadias. STUDY DESIGN: The authors retrospectively reviewed the charts of all patients with epispadias or bladder exstrophy/epispadias complex and severe dorsal chordee (>40°) who underwent epispadias repair with single-layer SIS for corporal body grafting. Clinical variables, surgical technique, and outcomes were analyzed. RESULTS: A total of nine consecutive patients underwent staged epispadias repair with dorsal corporal single-layer SIS grafting (summary figure). Of these, four (44.4%) had primary penopubic epispadias, one (11.1%) had mid-shaft epispadias, and four (44.4%) had bladder exstrophy/epispadias complex. The mean age at surgery was 13.4 ± 6 months. After phalloplasty with SIS grafting, there were no reported complications related to the graft during the post-operative period or follow-up visits. DISCUSSION: Although traditional techniques for epispadias repair allow some degree of corporal lengthening, they also result in abrupt medial rotation of the corporal bodies leading to torqueing and potential unsatisfactory cosmetic results. In contrast, the authors use single-layer SIS for corporal body grafting, and this study technique results in a more gradual inward rotation thus allowing more anatomical accuracy. Furthermore, an advantage of the use of SIS over other grafting materials is that there is no need to harvest an autologous graft such as tunica vaginalis or dermis. CONCLUSION: Epispadias repair using single-layer SIS corporal body grafting is an effective, safe, and feasible method, which provides satisfactory cosmesis and correction of dorsal curvature in congenital epispadias in children. Furthermore, a more normal penis appearance, without a decrease in the corporal length or diameter, is achieved with this technique.

Green synthesis of gold nanoparticles using brown algae Cystoseira baccata: Its activity in colon cancer cells.

This study is the first dealt with the use of brown macroalgae Cystoseira baccata (CB) extracts in obtaining gold nanoparticles (Au@CB) through an eco-friendly, fast, one-pot synthetic route. The formation of spherical, stable, polycrystalline nanoparticles with mean diameter of 8.4±2.2nm was demonstrated by UV-vis spectroscopy, TEM, HRTEM, STEM and zeta potential measurements. The extract appears to act as a protective agent where the particles are embedded, keeping them separated, avoiding aggregation and coalescence. The EELS and EDS analyses confirmed the elemental composition of the extract and nanoparticles. Moreover, the functional group of biomolecules present in CB and Au@CB were characterized by FTIR. The effects of CB extract and Au@CB were tested in vitro on the colon cancer cell lines HT-29 and Caco-2, as well as on normal primary neonatal dermal fibroblast cell line PCS-201-010. Results show a stronger cytotoxic effect against HT-29 than that on Caco-2; interestingly, a lack of toxicity on PCS-201-010 was obtained. Finally, the apoptotic activity was determined; Au@CB is able to induce apoptosis activation by the extrinsic and mitochondrial pathway in our CRC in vitro model. These encouraging results suggest that Au@CB has a significant potential for the treatment of colon rectal cancer.