Organic Phase-Soluble Nanomagnetically Cationic Phospholipid: Synthesis, Characterization, and In Vitro Transfection Activity.

The presented work describes the synthesis and characterization of a novel magnetic cationic phospholipid (MCP) system with a stable dopamine anchor as well as its transfection activity study. The synthesized architectural system increases the biocompatibility of iron oxide and promises applications of magnetic nanoparticles in living cells. The MCP system is soluble in organic solvents and can be easily adapted to prepare magnetic liposomes. We created complexes with liposomes containing MCP and other functional cationic lipids and pDNA as gene delivery tools, which possessed the ability to enhance the efficiency of transfection, particularly the process of interaction with cells by inducing a magnetic field. The MCP is able to create iron oxide nanoparticles and has the potential for the materials to prepare the system for site-specific gene delivery with the application of an external magnetic field.

Stimulant Abuse in Burn Patients Is Associated With an Increased Use of Hospital Resources.

Stimulant (cocaine, methamphetamine, and amphetamine) abuse compromises the peripheral vasculature through endothelial injury. In combination with the physiologic derangements seen in burn injuries, patients abusing stimulants may have additional impairments in wound healing. A retrospective review from July 1, 2015 to July 1, 2018 was performed at an American Burn Association-verified burn center. Patients with positive urine toxicology results for stimulants (ST(+)), and those without (ST(-)), who sustained burn injuries were identified and matched by age and TBSA. The primary outcome was mortality, and secondary outcomes included total length of stay (LOS), and need-for-surgery (grafting). In total, 130 patients ST(+) and 133 ST(-) patients were identified. There were no significant differences in age (40.9 ± 13.5 vs 39.2 ± 23.7 years, P = 0.46), Inhalation Injury (12.3 vs 9.0%, P = 0.39), or nutritional status (prealbumin: 17.3 ± 6.1 vs 17.1 ± 12.7 mg/dl, P = 0.66; albumin: 3.5 ± 0.6 vs 3.6 ± 0.7 g/dl, P = 0.45). There were no differences in mortality (6.1 vs 4.5%, P = 0.55), intensive care unit LOS (9.3 ± 16.5 vs 10.2 ± 20.9 days, P = 0.81), wound infections (15.4 vs 23.9%, P = 0.07), or wound conversion (6.9 vs 3.0%, P = 0.14). ST(+) patients had a significantly longer LOS (15.0 ± 16.9 vs 10.7 ± 17.3 days, P = 0.04), greater tobacco use (56.9 vs 18.0%, P = 0.00001), and greater need for grafting (54.6 vs 33.1%, P = 0.0004). ST(+) patients require more hospital resources-surgical operations and hospital days-than ST(-) patients. The increased need for surgical intervention may partially explain the increase in hospital days, in addition to the observation that ST(+) patients had more complex disposition issues than ST(-) patients.

Why does fluoride anion accelerate transmetalation between vinylsilane and palladium(II)-vinyl complex? Theoretical study.

Transmetalation between palladium(II)-vinyl complex and vinylsilane was theoretically investigated with the DFT and MP2 to MP4 methods to clarify the reaction mechanism and the reasons why fluoride anion accelerates the Pd-catalyzed cross-coupling reaction between vinyl iodide and vinylsilane. This transmetalation occurs with a very large activation barrier (45.8 kcal/mol) and a very large endothermicity (25.6 kcal/mol) in the absence of fluoride anion, where the potential energy change resulting from the solvation effect is evident. This is consistent with the experimental fact that this cross-coupling reaction does not proceed well in the absence of fluoride anion. The effects of fluoride anion were investigated in three possible reaction courses. In the first course, fluorovinylsilicate anion is formed before the transmetalation, and it reacts with the palladium(II)-vinyl complex. In the second course, an iodo ligand is substituted for fluoride anion, and then the transmetalation occurs between the palladium(II)-fluoro-vinyl complex and vinylsilane. In the third course, fluoride anion attacks the Si center of vinylsilane in the transition state of the transmetalation between the palladium(II)-iodo-vinyl complex and vinylsilane. Our theoretical calculation suggests that fluorovinylsilicate anion is not formed in the case of trimethylvinylsilane. In the second and third cases, the transmetalation occurs with a moderate activation barrier (E(a)) and a considerably large exothermicity (E(exo)): E(a) = 25.3 kcal/mol and E(exo) = 5.7 kcal/mol in the second course, and E(a) = 12.7 kcal/mol and E(exo) = 24.8 kcal/mol in the third course, indicating that fluoride anion accelerates the transmetalation via the second and third reaction courses. The acceleration of transmetalation by fluoride anion is clearly interpreted in terms of the formation of a very strong Si-F bond and the stabilization of the transition state by the hypervalent Si center, which is induced by the fluoride anion. Our computational results show that hydroxide anion accelerates the transmetalation in a manner similar to that observed with fluoride anion. From these results, we predict that the electronegative anion accelerates this transmetalation because the electronegative group forms a strong covalent bond with the silyl group and facilitates the formation of the hypervalent Si center in the transition state.