Structure Characterization of Biomedical Ti-Mo-Sn Alloy Prepared by Mechanical Alloying Method

The study presents the results of the influence of high energy milling on the structure of the new Ti–15Mo– 5Sn [wt%] alloy for biomedical applications. During testing the powders were milled for the following milling times: 5, 15, 30, and 45 h. The milled powders were characterized by X-ray diffraction, scanning and transmission electron microscopy methods. Observation of the powder morphology after various stages of milling leads to the conclusion that with the increase of the milling time the size of the powder particles as well as the degree of aggregation change. However, a clear tendency of particles reduction at every stage of the mechanical alloying process is clearly observed. The X-ray diffraction results confirmed the presence of the and phases, and molybdenum. It has been found that the reflections from the Sn phase disappeared after five hours of milling, suggesting that the Sn and Ti alloying took place, leading to the creation of a titanium-based solid solution. After 30 and 45 h of mechanical alloying the formation of the -Ti phase, the final share of which is 46(4) wt%, was observed. Furthermore, it was found that a diffraction line broadening with the increase of the milling time results from reduction of the crystallite size and an increase in the lattice distortion. The maximum level of the reduction of the crystallite size was obtained after 45 h of milling. The maximum degree of the unit cells reduction for all phases present in the powder that was being milled was also observed for this milling time

Cyclen-Based Cationic Lipids for Highly Efficient Gene Delivery towards Tumor Cells

Gene therapy has tremendous potential for both inherited and acquired diseases. However, delivery problems limited their clinical application, and new gene delivery vehicles with low cytotoxicity and high transfection efficiency are greatly required.In this report, we designed and synthesized three amphiphilic molecules (L1-L3) with the structures involving 1, 4, 7, 10-tetraazacyclododecane (cyclen), imidazolium and a hydrophobic dodecyl chain. Their interactions with plasmid DNA were studied via electrophoretic gel retardation assays, fluorescent quenching experiments, dynamic light scattering and transmission electron microscopy. The in vitro gene transfection assay and cytotoxicity assay were conducted in four cell lines.Results indicated that L1 and L3-formed liposomes could effectively bind to DNA to form well-shaped nanoparticles. Combining with neutral lipid DOPE, L3 was found with high efficiency in gene transfer in three tumor cell lines including A549, HepG2 and H460. The optimized gene transfection efficacy of L3 was nearly 5.5 times more efficient than that of the popular commercially available gene delivery agent Lipofectamine 2000™ in human lung carcinoma cells A549. In addition, since L1 and L3 had nearly no gene transfection performance in normal cells HEK293, these cationic lipids showed tumor cell-targeting property to a certain extent. No significant cytotoxicity was found for the lipoplexes formed by L1-L3, and their cytotoxicities were similar to or slightly lower than the lipoplexes prepared from Lipofectamine 2000™.Novel cyclen-based cationic lipids for effective in vitro gene transfection were founded, and these studies here may extend the application areas of macrocyclic polyamines, especially for cyclen

Normograms in prenatal life of stomach and urinary bladder in the second and third trimester of pregnancy

This research analyzes the measurement of fetal stomach and urinary bladder in healthy fetuses in the second and third trimester of gestation based on the database of the tertiary center from 2016 to 2019. The fetuses were selected for the study group in case they presented normal biometry and normal cardiac structure and function, no extracardiac malformation and no extracardiac anomalies and their gestational age was between 14 week  up to the 40 week of gestation. The normograms from the analysis are presented. The size of the fetal stomach and urinary bladder  (S/UB index) increases with gestational age on a 1:1 basis. Conclusions: The average size of the stomach in healthy fetuses between the 14 – 40 week of gestation was  18 mm (8 – 40 mm) , the average urinary bladder measurement was 17 mm (15 mm – 42 mm) and the fetal stomach to urinary bladder index (S/UB index) was constant:  1.26 (0.09 – 3.93). These are simple measurements that be implemented in daily practice for fetal ultrasound assessment</jats:p