25 research outputs found
Crystallization Control of N,Nâ˛-Dioctyl Perylene Diimide by Amphiphilic Block Copolymers Containing poly(3-Hexylthiophene) and Polyethylene Glycol
The preparation of micron- to nanometer-sized functional materials with well-defined shapes and packing is a key process to their applications. There are many ways to control the crystal growth of organic semiconductors. Adding polymer additives has been proven a robust strategy to optimize semiconductor crystal structure and the corresponding optoelectronic properties. We have found that poly(3-hexylthiophene) (P3HT) can effectively regulate the crystallization behavior of N,Nâ˛-dioctyl perylene diimide (C8PDI). In this study, we combined P3HT and polyethylene glycol (PEG) to amphiphilic block copolymers and studied the crystallization modification effect of these block copolymers. It is found that the crystallization modification effect of the block copolymers is retained and gradually enhanced with P3HT content. The length of C8PDI crystals were well controlled from 2 to 0.4 Οm, and the width from 210 to 35 nm. On the other hand, due to the water solubility of PEG block, crystalline PEG-b-P3HT/C8PDI micelles in water were successfully prepared, and this water phase colloid could be stable for more than 2 weeks, which provides a new way to prepare pollution-free aqueous organic semiconductor inks for printing electronic devices
Protein Adsorption Switch Constructed by a Pillar[5]areneâBased HostâGuest Interaction
The interfacial properties of solid substrates are of importance for protein adsorption. Herein, we report a reversible protein adsorption switch based on the hostâguest interaction of the butoxy pillar[5]arene and adipic acid. By the detector of the contact angle (CA), atomic force microscopy (AFM), and luminoscope on the silicon substrate, the intelligent protein switch exhibits excellent adsorptivity for BSA and switch performance by pH regulation.Natural design: Learning from natural biological switches, we present the example of a new protein adsorption switch successfully designed by pH adjustment based on the hostâguest reversible system of the butoxy pillar[5]arene (WP5) and adipic acid (see scheme). The intelligent protein switch exhibits excellent adsorptivity for BSA and switch performance by pH regulation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137280/1/chem201504076-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137280/2/chem201504076.pd
Temperature-Responsive Switch Constructed from an Anthracene-Functionalized Pillar[5]arene-Based HostâGuest System
A monofunctionalized anthracene pillar[5]Âarene
(MAP5) was designed
and synthesized by a click reaction. MAP5 was bound to an ionic liquid
through hostâguest interactions to modify a gold interface.
The bonding and release of MAP5 was readily and reversibly controlled
by temperature regulation. The developed temperature-responsive switch
at an interface can be used in memory storage, drug delivery, and
sensing
Bipyrene-Functionalized Graphene as a âTurn-Onâ Fluorescence Sensor for Manganese(II) Ions in Living cells
1,2-bis-(2-pyren-1-ylmethylamino-ethoxy) ethane (NPEY)
was synthesized
and brought to the surface of graphene nanosheets (GNs) via ĎâĎ
stacking, which provided a simple and convenient route for processing
âturn-onâ fluorescent sensor by simply mixing the diluted
aqueous solutions of both components. The synthesized NPEY modified
graphene nanosheets (NPEY-GNs) not only allows good selectivity toward
Mn<sup>2+</sup> with the detection limit of 4.6 Ă 10<sup>â5</sup> M, but also shows âturn-onâ response for Mn<sup>2+</sup> both in vitro and in living cells. These sensing capabilities
of NPEY-GNs in living cells make it a robust candidate for many biological
fields, such as intracellular tracking, intracellular imaging, etc
The risks of low hemoglobin deferral in a large retrospective cohort of plasmapheresis donors and the influence factors of return for a subsequent donation in China
Background According to the Technical Operation Procedures for Plasmapheresis Collection Station (2019) in China, plasmapheresis donors with low hemoglobin (Hb) levels (men <12.0 g/dL; women <11.0 g/dL) were deferred for at least 2 weeks. The purpose of this retrospective study was to survey the demographic characteristics of plasmapheresis donors with low Hb deferral (LHD) and identify at-risk LHD donors, so as to enhance donor safety and improve donation service management. Methods From 2018 to 2020, a multi-center study involving plasmapheresis donors from 18 plasmapheresis centers in three provinces (Sichuan, Yunnan and Hunan) of China was conducted. Donor demographics (age, sex) and donation information (date of donation, first-time donors vs. repeat donors, the number of lifetime donations, the number of donations in the last 12 months, and whether the LHD donor returned for a subsequent donation) were collected. The Cochran-Mantel-Haenszel method was used to explore the risk factors for LHD while adjusting for the different provinces. Logistic regression analysis was used to investigate the factors influencing the return for a subsequent donation after LHD. Results A total of 497,039 plasmapheresis donors were included. Female donorsâ LHD rate was 0.15% on average, while male donorsâ LHD rate was 0.01%. Female donors aged 41â50 years old (OR: 2.276, 95% CI [1.333â3.887], p = 0.002) were more likely to experience LHD temporarily than those aged 18â30 years old. For female donors, compared with donations in the winter, they had a higher risk for LHD in the summer (OR: 2.217, 95% CI [1.670â2.943], p < 0.001), spring (OR: 2.402, 95% CI [1.806â3.196], p < 0.001), and fall (OR: 2.002, 95% CI [1.500â2.673], p < 0.001). Among the LHD donors, those who had donated more frequently in the past were more likely to return for a subsequent donation (p = 0.012). Conclusions Female donors were at a higher risk of LHD, particularly between the ages of 41 and 50. A clear seasonal pattern in the rate of LHD was observed. In the winter, the risk of LHD was the lowest; thus, it was advised to recruit plasmapheresis donors throughout the winter and to make the required adjustments for recruitment measures during other seasons. The number of previous donations was correlated with the return rate after LHD. Our observations could have practical implications for plasmapheresis donor management
Liquid Quantum Dots Constructed by HostâGuest Interaction
It
is a challenging task to construct nonionic liquid quantum dots
(QDs) with highly optical perfermance. To address the problem, we
make a new strategy to construct liquid QDs via hostâguest
interaction between β-cyclodextrin and adamantane. Macroscopic
fluidity and optical performance of liquid QDs can be controlled by
the length of polyethylene glycol. The supramolecular compounds can
make use of its excellent inclusion capacities to fasten flexible
organic long-chain compounds on the surface of QDs to become nonionic.
Compared with the ionic liquid QDs, nonionic liquid QDs based on supramolecular
self-assembly offered a strong, fast hostâguest interaction,
avoiding multistep reactions that would be more favorable for maintaining
the fluorescent property of QDs
Evaluation of topical methylene blue nanoemulsion for wound healing in diabetic mice
AbstractContext Diabetic wounds (DW) are a complication of diabetes and slow wound healing is the main manifestation. Methylene blue (MB) has been shown to exhibit therapeutic effects on diabetes-related diseases.Objective To investigate the mechanisms of action of MB-nanoemulsion (NE) in the treatment of DW.Materials and methods The concentration of MB-NE used in the in vivo and in vitro experiments was 0.1âmg/mL. Streptozocin-induced diabetic mice were used as models. The mice were separated into nondiabetic, diabetic, MB-NE treated, and NE-treated groups. Intervention of high glucose-induced human umbilical vein endothelial cells using MB-NE. The mechanism by which MB-NE promotes DW healing is investigated by combining histological analysis, immunofluorescence analysis, TUNEL and ROS assays and western blotting.Results In diabetic mice, the MB-NE accelerated DW healing (pâ<â0.05), promoted the expression of endothelial cell markers (Îą-SMA, CD31 and VEGF) (pâ<â0.05), and reduced TUNEL levels. In vitro, MB accelerated the migration rate of cells (pâ<â0.05); promoted the expression of CD31, VEGF, anti-apoptotic protein Bcl2 (pâ<â0.05) and decreased the expression of the pro-apoptotic proteins cleaved caspase-3 and Bax (pâ<â0.05). MB upregulated the expression of Nrf2, catalase, HO-1 and SOD2 (pâ<â0.05). In addition, MB reduced the immunofluorescence intensity of TUNEL and ROS in cells and reduced apoptosis. The therapeutic effect of MB was attenuated after treatment with an Nrf2 inhibitor (ML385).Discussion and conclusion This study provides a foundation for the application of MB-NE in the treatment of DW
Alanine-Based Chiral Metallogels via Supramolecular Coordination Complex Platforms: Metallogelation Induced Chirality Transfer
Chiral self-assemblies constantly attract great interest because of their potential to provide insight into biological systems and materials science. Herein we report on the efficient preparation of alanine-based chiral metallacycles, rhomboids 1D and 1L and hexagons 2D and 2L using a Pt(II) â pyridyl directional bonding approach. The metallacycles are subsequently assembled into nanospheres at low concentration, that generate chiral metallogels at high concentration driven by hydrogen bonding, hydrophobic and ĎâĎ interactions. The gels consist of microscopic chiral nanofibers with well-defined helicity, as confirmed by circular dichroism (CD) and scanning (SEM) and transmission electron (TEM) microscopies. Given these results, we expect this technique will not only unlock interesting new approaches to understand homochirality in nature but also allow the design of versatile soft materials containing chiral supramolecular cores