Role of Curvature-Sensing Proteins in the Uptake of Nanoparticles with Different Mechanical Properties

Nanoparticles of different properties, such as size, charge, and rigidity, are used for drug delivery. Upon interaction with the cell membrane, because of their curvature, nanoparticles can bend the lipid bilayer. Recent results show that cellular proteins capable of sensing membrane curvature are involved in nanoparticle uptake; however, no information is yet available on whether nanoparticle mechanical properties also affect their activity. Here liposomes and liposome-coated silica are used as a model system to compare uptake and cell behavior of two nanoparticles of similar size and charge, but different mechanical properties. High-sensitivity flow cytometry, cryo-TEM, and fluorescence correlation spectroscopy confirm lipid deposition on the silica. Atomic force microscopy is used to quantify the deformation of individual nanoparticles at increasing imaging forces, confirming that the two nanoparticles display distinct mechanical properties. Uptake studies in HeLa and A549 cells indicate that liposome uptake is higher than for the liposome-coated silica. RNA interference studies to silence their expression show that different curvature-sensing proteins are involved in the uptake of both nanoparticles in both cell types. These results confirm that curvature-sensing proteins have a role in nanoparticle uptake, which is not restricted to harder nanoparticles, but includes softer nanomaterials commonly used for nanomedicine applications.</p

Anisotropic Ferromagnetic Organic Nanoflowers

We report a weak anisotropic ferromagnetic behavior in a purely organic molecule at room temperature, a property rarely reported in organic nanomaterials. The reported 1,2-bis(tritylthio)ethane, forming plate- and organic-flower-like morphologies at the nanolevel, is the first organic crystal with an inherent magnetic property at 300 and 2 K. However, at low temperatures, the magnetization value [Mmax(T) ∼116 emu/mol at 2 K] increases drastically at 3 orders higher compared to 300 K. Interestingly, the system exhibits strong anisotropy with an anisotropic constant, K1 ∼3.25 7 103 erg/cc, and anisotropy field, HK ∼3.25 kOe. Below 10 K, this system displays unusual temperature dependence of the coercive field [HC(T)] and remanence magnetization [MR(T)] with a hysteresis-peak anomaly (T∗ ∼10-15 K) due to the enhanced spin-orbit coupling. The maximum HC and MR at T∗ were HC = 220 Oe and MR ∼12 emu/mol, respectively. Beyond T*, HC(T) and MR(T) drop continuously and become negligible as the measurement temperature approaches 300 K. Our results demonstrate that the triphenyl molecules can be further exploited for the design and synthesis of organic magnets for possible applications in spintronics and memory storage devices

On 12 th to 14 th December Organized by ROAD SAFETY AWARENESS INDEX &amp; ROAD USER BEHAVIOR-A CASE STUDY AT KAZHAKKOOTTAM

ABSTRACT This article reports the results of a case study of road user characteristics with regard to road safety. The two main characteristics considered were road user awareness and road user behavior. Influence of Road user awareness on road safety was studied. Questionnaire survey method was done to find the influence of age and educational qualification on awareness of road users and developed Road Safety Awareness Index (RSAI). It is found that age and educational qualification are not completely deciding factors of road user awareness. To determine the reasons for traffic violation, road user behavior observation surveys were done. It is also tried to cross examine whether any other authentic factors which enhance traffic violations, previous accident history and enforcement measures were taken as factors. And the authors could find out a strong relation among them