Flow and Tableting Behaviors of Some Egyptian Kaolin Powders as Potential Pharmaceutical Excipients

The present work aimed at assessing the pharmaceutical tableting properties of some Egyptian kaolin samples belong to the Abu Zenima kaolin deposits (estimated at 120 million tons). Four representative samples were selected based on kaolinite richness and their structural order-disorder degree, and after purification, they were dried at 70 ºC and heated from room temperature up to 400 ºC (10 ºC/min). Mineralogy, micromorphology, microtexture, granulometry, porosimetry, moisture content, bulk and tapped density, direct and indirect flowability, and tableting characteristics are studied. Results indicated that purified kaolin samples were made up of 95–99% kaolinite, <3% illite, 1% quartz and 1% anatase. The powder showed mesoporous character (pore diameters from 2 to 38 nm and total pore volume from 0.064 to 0.136 cm3/g) with dominance of fine nanosized particles (<1 um–10 nm). The powder flow characteristics of both the ordered (Hinckley Index HI > 0.7, crystallite size D001 > 30 nm) and disordered (HI < 0.7, D001 < 30 nm) kaolinite-rich samples have been improved (Hausner ratio between 1.24 and 1.09) as their densities were influenced by thermal treatment (with some observed changes in the kaolinite XRD reflection profiles) and by moisture content (variable between 2.98% and 5.82%). The obtained tablets exhibited hardness between 33 and 44 N only from the dehydrated powders at 400 ºC, with elastic recovery (ER) between 21.74% and 25.61%, ejection stress (ES) between 7.85 and 11.45 MPa and tensile fracture stress (TFS) between 1.85 and 2.32 MPa, which are strongly correlated with crystallinity (HI) and flowability (HR) parameters. These findings on quality indicators showed the promising pharmaceutical tabletability of the studied Egyptian kaolin powders and the optimization factors for their manufacturability and compactability.This work has been funded by the Egyptian Cultural Affairs and Missions Sector (Plan 2013–2014), Ministry of Higher Education, in collaboration with the Group CTS-946 (Junta de Andalucía) and MINECO project CGL2016-80833-R (Spain), and the grant funded by Erasmus+ KA1 mobility program 2016/2017

Design of innovative and low-cost dopamine-biotin conjugate sensor for the efficient detection of protein and cancer cells

: The rapid, precise identification and quantification of specific biomarkers, toxins, or pathogens is currently a key strategy for achieving more efficient diagnoses. Herein a dopamine-biotin monomer was synthetized and oxidized in the presence of hexamethylenediamine, to obtain adhesive coatings based on polydopamine-biotin (PDA-BT) on different materials to be used in targeted molecular therapy. Insight into the structure of the PDA-BT coating was obtained by solid-state 13C NMR spectroscopy acquired, for the first time, directly onto the coating, deposited on alumina spheres. The receptor binding capacity of the PDA-BT coating toward 4-hydroxyazobenzene-2-carboxylic acid/Avidin complex was verified by means of UV-vis spectroscopy. Different deposition cycles of avidin onto the PDA-BT coating by layer-by-layer assembly showed that the film retains its receptor binding capacity for at least eight consecutive cycles. Finally, the feasibility of PDA-BT coating to recognize cell lines with different grade of overexpression of biotin receptors (BR) was investigated by tumor cell capture experiments by using MCF-7 (BR+) and HL-60 (BR-) cell lines. The results show that the developed system can selectively capture MCF-7 cells indicating that it could represent a first approach for the development of future more sophisticated biosensors easily accessible, low cost and recyclable with the dual and rapid detection of both proteins and cells

Nanocomposite gels of poloxamine and Laponite for β-Lapachone release in anticancer therapy

Nano-hybrid systems have been shown to be an attractive platform for drug delivery. Laponite® RD (LAP), a biocompatible synthetic clay, has been exploited for its ability to establish of strong secondary interactions with guest compounds and hybridization with polymers or small molecules that improves, for instance, cell adhesion, proliferation, and differentiation or facilitates drug attachment to their surfaces through charge interaction. In this work, LAP was combined with Tetronics, X-shaped amphiphilic PPO-PEO (poly (propylene oxide)–poly (ethylene oxide) block copolymers. β-Lapachone (BLPC) was selected for its anticancer activity and its limited bioavailability due to very low aqueous solubility, with the aim to improve this by using LAP/Tetronic nano-hybrid systems. The nanocarriers were prepared over a range of Tetronic 1304 concentrations (1 to 20% w/w) and LAP (0 to 3% w/w). A combination of physicochemical methods was employed to characterize the hybrid systems, including rheology, particle size and shape (DLS, TEM), thermal analysis (TG and DSC), FTIR, solubility studies and drug release experiments. In vitro cytotoxicity assays were performed with BALB/3T3 and MCF-7 cell lines. In hybrid systems, a sol-gel transition can occur below physiological temperature. BLPC exhibits the most significant increase in solubility in formulations with a high concentration of T1304 (over 10% w/w) and 1.5% w/w LAP, or systems with only LAP (1.5%), with a 50 and 100-fold increase in solubilisation, respectively. TEM images showed spherical micelles of T1304, which elongated into wormlike micelles with concentration (20%) and in the presence of LAP, a finding that has not been reported before. A sustained release of BLPC over 140 hours was achieved in one of the formulations (10% T1304 with 1.5% laponite), which also showed the best selectivity index towards cancer cells (MCF-7) over BALB/3T3 cell lines. In conclusion, BLPC-loaded T1304/LAP nano-hybrid systems proved safe and highly effective and are thus a promising formulation for anticancer therapy.Financial support for this research was provided by the Coordination of Improvement of Higher-Level Personnel - Brazil (CAPES) - 1575/2015. We also acknowledge the collaboration of Prof. Dr. Daniele Ribeiro de Araujo from Federal University of ABC for the rheological experiments. Dr. Raquel de Melo Barbosa acknowledges the grant for mobility to Brazilian professors from Fundación Carolina (Spain), the Spanish research group CTS-946, to the Centre for Scientific Instrumentation (Centro de Instrumentación Científica or CIC) for transmission microscopy analysis and the Andalusian Earth Sciences Institute (IACT) for support during her mobility period in Spain

Does Sedimentology have a role in the energy transition? A proposal

El proyecto SOSGAS tiene por objeto calibrar el impacto de la heterogeneidad sedimentaria inherente a formaciones fluviales y deltaicas en el geo-almacenamiento sostenible de CO2 y H2 verde. Se han seleccionado 6 ejemplos mesozoicos y cenozoicos en la Meseta Ibérica, la Cuenca del Ebro y la Cuenca de Graus-Tremp a los que se aplica el flujo de trabajo OBO. Con esta base de datos de afloramiento y subsuelo se construyen modelos estáticos 3D de distribución de facies reservorio y sello y de propiedades petrofísicas, y finalmente se simula la inyección de los fluidos. Diferentes hipótesis de conectividad entre litofacies porosas y de distribución de los sellos conducen a diferentes escenarios de dinámica de fluidos y de entrampamiento. Con este proyecto iniciamos una línea de investigación que permitirá evaluar la validez de la sedimentología para contribuir al reto social de la transición energética.The SOSGAS project aims to gauge the impact of sedimentary heterogeneity inherent to fluvial and deltaic formations on the sustainability of a possible geo-storage of CO2 and green H2. 6 Mesozoic and Cenozoic examples have been selected in the Iberian Meseta, the Ebro Basin and the Graus-Tremp Basin to which the OBO workflow is applied. Using this outcrop and subsurface database, 3D static models are constructed to reproduce the distribution of reservoir and seal facies and petrophysical properties, and finally fluid injection is simulated. Different hypotheses of connectivity of porous lithofacies and seal distribution lead to different scenarios of fluid flow dynamics and trapping. With this project, we are initiating a line of research that will make it possible to assess the validity of sedimentology in contributing to the social challenge of the energy transition.Grants PID2022-140850OB-C21 and PID2022-140850OB-C22 funded by MCIN/AEI/10.13039/501100011033/ and by “ERDF A way of making Europe”. REPSOL EP, CEPSA EP, ENAGAS, SLB, AGGEP, the MS2022-17 contract -NextGenerationEU- and the groups RNM369 (PAI) and 2021SGR00076 (GC) are also grateful

Drilling Predation on Serpulid Polychaetes (Ditrupa arietina) from the Pliocene of the Cope Basin, Murcia Region, Southeastern Spain

We report quantitative analyses of drilling predation on the free-living, tube-dwelling serpulid polychaete Ditrupa arietina from the Cope Cabo marine succession (Pliocene, Spain). Tubes of D. arietina are abundant in the sampled units: 9 bulk samples from 5 horizons yielded ∼5925 specimens of D. arietina. Except for fragmentation, tubes were well preserved. Complete specimens ranged from 3.1 to 13.4 mm in length and displayed allometric growth patterns, with larger specimens being relatively slimmer. Drilled Ditrupa tubes were observed in all samples. Drillholes, identified as Oichnus paraboloides, were characterized by circular to elliptical outline (drillhole eccentricity increased with its diameter), parabolic vertical profile, outer diameter larger than inner diameter, penetration of one tube wall only, narrow range of drill-hole sizes, and non-random (anterior) distribution of drillholes. A total of 233 drilled specimens were identified, with drilling frequencies varying across horizons from 2.7% to 21% (3.9% for pooled data). Many tube fragments were broken across a drillhole suggesting that the reported frequencies are conservative and that biologically-facilitated (drill-hole induced) fragmentation hampers fossil preservation of complete serpulid tubes. No failed or repaired holes were observed. Multiple complete drillholes were present (3.9%). Drilled specimens were significantly smaller than undrilled specimens and tube length and drill-hole diameter were weakly correlated. The results suggest that drillholes were produced by a size-selective, site-stereotypic predatory organism of unknown affinity. The qualitative and quantitative patterns reported here are mostly consistent with previous reports on recent and fossil Ditrupa and reveal parallels with drilling patterns documented for scaphopod mollusks, a group that is ecologically and morphologically similar to Ditrupa. Consistent with previous studies, the results suggest that free-dwelling serpulid polychaetes are preyed upon by drilling predators and may provide a viable source of data on biotic interactions in the fossil record

Adsorption of 5-aminosalicylic acid on kaolinite surfaces at a molecular level

The application of clay minerals in therapeutics is becoming important due to their structural and surface physicochemical properties. 5-aminosalicylic acid (5-ASA) is a very common pharmaceutical drug and is used worldwide. The interactions between the 5-ASA molecule and both the aluminol and siloxane surfaces of kaolinite are studied by means of atomistic calculations using force fields based on empirical interatomic potentials and quantum mechanics calculations based on density functional theory. A conformational analysis of 5-ASA has been performed and the anion of 5-ASA was also studied. The calculated adsorption energy values indicate that 5-ASA is likely to be adsorbed on the kaolinite surfaces with greater affinity to the aluminol surface. Hence, kaolinite may be considered as a promising pharmaceutical carrier of 5-ASA

Efectos de la heterocromatina supernumeraria sobre la formación de los quiasmas y la actividad nucleolar

14 páginas, 6 figuras.El significado biológico de los polimorfismos para heterocromatina puede ser esclacido, en parte, mediante el análisis de sus efectos sobre una variedad de caracteres. El más investigado, hasta ahora, es la influencia sobre la formación de los quiasmas, aunque el de este carácter no parece llegar a aclararse. Se revisan aquí los estudios existentes sobre los efectos producidos por los tres principaies tipos de heterocromatina supernumeraria existentes en los saltamontes -cromosomas polisómicos, cromosomas accesorios y segmentos cromosómicos supernumerarios- sobre la frecuencia y distribucih de los quiasmas. Además, examinamos los efectos demostrados en los últimos años por nuestro equipo investigador sobre la actividad de las regiones organizadoras de nucleolo.Peer reviewe