Selenium-containing Polymers Research Articles

Diselenide–yne chemistry for selenium-containing linear polymer modification

Selenium-containing brush polymers with diverse functional segments were easily prepared through diselenide–yne chemistry.

Thermosensitive Poly(DHSe/PEG/PPG Urethane)-Based Hydrogel Extended Remdesivir Application in Ophthalmic Medication.

The spread of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the coronavirus disease 2019 (COVID-19) outbreak beginning in March 2020. Currently, there is a lack of suitable dose formulations that interrupt novel coronavirus transmission via corneal and conjunctival routes. In the present study, we developed and evaluated a thermosensitive gelling system based on a selenium-containing polymer for topical ocular continuous drug release. In detail, di-(1-hydroxylundecyl) selenide (DHSe), poly(ethylene glycol) (PEG), and poly(propylene glycol) (PPG) were polymerized to form poly(DHSe/PEG/PPG urethane). The polymer was used to carry poorly water-soluble remdesivir (RDV) at room temperature to form the final thermosensitive in situ gel, which exhibited a typical sol-gel transition at 35 °C. The formed polymer was further characterized by rheology, thermology, and scanning electron microscopy. In vitro release studies and in vivo retention and penetration tests indicated that the thermogel provided the prolonged release of RDV. The RDV-loaded in situ gel was proven to be non-biotoxic against human corneal epithelial cells, with good ocular tolerance and biocompatibility in rabbit eyes.

Preparation of highly transparent poly(meth)acrylates with enhanced refractive indices by radical (co)polymerization of seleno(meth)acrylates

Over the years, selenium-containing polymers have attracted increasing interest as high-refractive index materials. In this study, two transparent high-refractive-index polymer series were prepared by the radical polymerization of phenyl selenomethacrylate (PhSeM) and phenyl selenoacrylate (PhSeA), and their copolymerization with methyl methacrylate (MMA). The refractive indices of the poly(PhSeM) and poly(PhSeA) homopolymer films were 1.6426 and 1.6519, respectively at 589 nm with Abbe numbers in the range 27.2–24.1, making them ideal monomers for improving the refractive indices of (meth)acrylate-based copolymers. By increasing the MMA content, the refractive indices of these copolymers were reduced from 1.6207 into 1.5181 with Abbe numbers in the range 25.7–53.1. Both homopolymers exhibited excellent transmittances (>94%) at the wavelength 400 nm. Moreover, owing to their higher MMA content, the selenium-containing copolymers exhibited a higher transparency (95–99%) than the homopolymers, which is highly desirable for optically transparent materials.

Photo masking via breaking alkyl C Se bond of selenium-containing maleimide polymers by ultraviolet light

• Obtained polymer with alkyl C Se bond has similar transparency with polystyrene (PS), higher the refractive index than PS and comparable thermostability with PS. • The pattern is directly visual under natural light without any extra treatments and the reaction condition of photo-corsslinking does not require photoacid, photoinitiator and other agents. • The obtained pattern has excellent solution resistance, duo to its cross-linked structure. • The pattern keeps a smooth surface without deformation, which avoides its distortion. To investigate the complexity of breaking aryl C Se bond, alkyl C Se bond and alkyl C S bond by ultraviolet light, three maleimide polymers are employed as objects, including SePhP which reported in our previous work having aryl C Se bond, SePP which synthesized via radical copolymerization of N -(4-selenophenyl)-propyl maleimide and styrene having alkyl C Se bond and SPP which synthesized via radical copolymerization of N -(4-thiophenyl)-propyl maleimide and styrene having alkyl C S bond. After careful structure characteristics, SePhP, SePP and SPP are treated by ultraviolet light, as a result, only C Se bond of SePP can be broken. When SePP is irradiated by ultraviolet light in an oxygen-free condition, it can make a structure change from linear to cross-linked and refractive index decrease of polymer. Furthermore, utilizing photo-crosslinking and changing of refractive index of SePP after ultraviolet light irradiation, we realize visual photomask patterning in a simple system, which will bring great potential in display devices, anti-counterfeit labels, and etc.

Room-Temperature Metal-Free Multicomponent Polymerizations of Elemental Selenium toward Stable Alicyclic Poly(oxaselenolane)s with High Refractive Index.

Selenium-containing polymers are a group of fascinating functional polymers with unique structures, properties, and applications, which have been developed recently but only with limited examples. The challenges of developing selenium-containing polymers with structural and functional diversity include the lack of economic and safe monomers, lack of efficient and convenient synthetic approaches, and poor stability of selenium-involving covalent bonds. In this work, room-temperature metal-free multicomponent polymerizations (MCPs) of elemental selenium, diisocyanides, and dipropargyl alcohols were developed, and polymers with a selenium-containing aliphatic heterocycle, 1,3-oxaselenolane, were synthesized through these MCPs directly from elemental selenium. The alicyclic poly(oxaselenolane)s enjoyed high yields (up to 93%), high molecular weights (up to 15 600 g/mol), high thermal and chemical stability, good solubility and processability. With the structural design of the poly(oxaselenolane)s and their high selenium contents of up to 33.7 wt %, the refractive indices of their spin-coated thin films could reach 1.8026 at 633 nm and maintain 1.7770 at 1700 nm. It is anticipated that these efficient, convenient, mild, and economic multicomponent polymerizations of elemental selenium can promote the selenium-related polymer chemistry and accelerate the exploration of diversified selenium-containing functional polymer materials.

Recent developments in selenium-containing polymeric micelles: prospective stimuli, drug-release behaviors, and intrinsic anticancer activity.

Selenium is capable of forming a dynamic covalent bond with itself and other elements and can undergo metathesis and regeneration reactions under optimum conditions. Its dynamic nature endows selenium-containing polymers with striking sensitivity towards some environmental alterations. In the past decade, several selenium-containing polymers were synthesized and used for the preparation of oxidation-, reduction-, and radiation-responsive nanocarriers. Recently, thioredoxin reductase, sonication, and osmotic pressure triggered the cleavage of Se-Se bonds and swelling or disassembly of nanostructures. Moreover, some selenium-containing nanocarriers form oxidation products such as seleninic acids and acrylates with inherent anticancer activities. Thus, selenium-containing polymers hold promise for the fabrication of ultrasensitive and multifunctional nanocarriers of radiotherapeutic, chemotherapeutic, and immunotherapeutic significance. Herein, we discuss the most recent developments in selenium-containing polymeric micelles in light of their architecture, multiple stimuli-responsive properties, emerging immunomodulatory activities, and future perspectives in the delivery and controlled release of anticancer agents.

Visual Ozone Sensor: Structural Color Change of Pendant Selenium-Containing Maleimide Polymers via Oxidation.

Pendant selenium-containing maleimide polymers with different selenium contents are synthesized via a radical copolymerization of styrene and N-butylmaleimide phenyl selenide. The polymer structures are characterized by nuclear magnetic resonance, gel permeation chromatography, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, and scanning electron microscopy with an energy-dispersive spectrometer, which results in the desired structures and selenium contents. The refractive indices of the polymers, which change as a function of different contents of selenium and oxidative stimuli by H2 O2 or O3 , are investigated. Finally, a photonic crystal (PC) is prepared based on the selenium-containing polymer. The visible color changes of the PC are investigated as a function of different concentrations and contact times of O3 .

Functional Polyselenoureas for Selective Gold Recovery Prepared from Catalyst-Free Multicomponent Polymerizations of Elemental Selenium

Selenium-containing polymers with fascinating functionalities such as stimuli-responsive property, enzyme mimics, antioxidant activity, promotion of immune-cell activity, anticancer activity, and c...

Selenium-containing polymers: synthesis and applications

Selenium-containing polymers: synthesis and applications

Selenium-Containing Polymers: Perspectives toward Diverse Applications in Both Adaptive and Biomedical Materials

Selenium is a semimetallic element lying in group XVI of the periodic table with its chemical properties resembling sulfur. But owing to its relatively low electronegativity and large atomic radius compared with sulfur, selenium also shows unique properties. This feature endows selenium-containing compounds with high reactivity and sensitivity. Although organic selenium chemistry has been developing very fast, the successful introduction of selenium into polymer science is rather scarce. Fortunately, we have seen a drastic rising trend in the area of selenium-containing polymers over the past decade. In this Perspective, the synthetic routes of selenium-containing polymers are summarized, and their unique stimuli-responsive properties are elaborated on, together with their diverse applications in the field of adaptive and biomedical materials.

Well-Defined Selenium-Containing Aliphatic Polycarbonates via Lipase-Catalyzed Ring-Opening Polymerization of Selenic Macrocyclic Carbonate Monomer.

The synthesis of well-defined, biodegradable selenium-containing polymers remains a formidable challenge in polymer chemistry. Herein, a selenic cyclic carbonate dimer monomer (MSe) was developed to generate well-defined, biodegradable aliphatic polycarbonates with selenide functionality on the backbone. The monomer was synthesized via the intermolecular cyclization of di(1-hydroxyethylene) selenide and diphenyl carbonate with lipase CA as catalysts in a mass of anhydrous toluene with very dilute monomer concentration. Then living ring-opening polymerization (ROP) was executed by solution method using the same lipase CA as catalysts. Similarly, the copolymerizations with commercial trimethylene carbonate (TMC) generated random copolymers demonstrated by 13C NMR, regulating the density of selenium functional groups. The resulting polymers exhibited a living polymerization characteristic, as evidenced by polymerization kinetics, predictable molecular weights, narrow molecular-weight distribution, and controlled copolymer compositions. Using hydrophilic macroinitiators (PEG), amphiphilic di/triblock copolymers could be obtained, suggesting their potential as controlled drug delivery system (DDS) and hydrogel scaffolds for tissue engineering.

Organoselenium Polymer Inhibits Biofilm Formation in Polypropylene Contact Lens Case Material.

Contact lens-acquired bacterial infections are a serious problem. Of the reported cases, inadequate cleaning of the lens case was the most common cause of lens contamination. Organoselenium has been shown to inhibit bacterial attachment to different polymer materials. This study evaluates the ability of an organoselenium monomer, incorporated into the polymer of a polypropylene contact lens case coupon, to block the formation of biofilms in a lens case. The bacteria tested were Pseudomonas aeruginosa, Staphylococcus aureus, Stenotrophomonas maltophilia, and Serratia marcescens. For this study, the bacteria were allowed to grow overnight, in trypticase soy broth media, in the presence of the selenium-containing polymer or the same polymer without organoselenium. The material was studied by both colony-forming unit determination and by confocal laser scanning microscopy. The results showed that the organoselenium polymer versus the control polymer resulted in the following effect on biofilm formation: (1) a reduction in P. aeruginosa of 7.3 logs (100%); (2) a reduction in S. aureus of 7.3 logs (100%); (3) a reduction in S. maltophilia of 7.5 logs (100%); and (4) a reduction in S. marcescens reduction of 3.3 logs (99.9%). To test the stability of the organoselenium polypropylene contact lens coupon, the coupon was soaked in PBS for eight weeks at room temperature. It was found that when these soaked coupons were tested against S. aureus, complete inhibition (8.1 logs) was obtained. Because organoselenium cannot leach from the polymer, this would imply that the organoselenium polypropylene contact lens case coupon would be inhibitory toward bacterial biofilm for the life of the case. The organoselenium polypropylene contact lens case coupon shows the ability to inhibit biofilm formation. The use of organoselenium copolymer should play an important role in protecting against contact lens case-acquired infection.

ROS responsive selenium-containing polymers

ROS responsive selenium-containing polymers

Analysis of Structure and Electrochemistry of Selenium-Containing Conductive Polymer Materials for Rechargeable Lithium Batteries

Correlation between the structure of selenized poly(acrylonitrile) (Se/PAN) composite materials and their electrochemical properties for lithium batteries was studied. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements demonstrate that higher synthesis temperature results in a higher graphitization degree of the polymer skeleton and fewer Se-Se bonds. The Se/PAN electrodes present excellent rate capability and extra-long cycle life due to their fast electrochemical reaction kinetics and high structural stability. A reversible specific capacity of about 325 mA h g−1 for the Se/PAN composite synthesized at 500°C was obtained with a capacity decay of only 2.6% (based on the second cycle) after 1500 cycles. Furthermore, the correlation between their structure and electrochemical performance was elucidated. The Se/PAN composites obtained at higher temperature show better cycling stability but lower capacity.

A Straightforward Method for Preparing Well-Defined Responsive Diselenide-Containing Polymers Based on ATRP.

Diselenide-containing polymers are facilely synthesized from polymers prepared by atom transfer radical polymerization (ATRP). Benefiting from the ATRP technology, this protocol provides a flexible route for controlling the polymer structure, which allows for a great variety of architectures of selenium-containing polymer materials for applications in various fields. The oxidative and reductive responsive behavior of the obtained diselenide-containing polymers is also investigated.

Amphiphilic diselenide-containing supramolecular polymers

This communication describes the fabrication of diselenide-containing supramolecular polymers.

Coordination-responsive selenium-containing polymer micelles for controlled drug release

Coordination-responsive selenium-containing polymer micelles for controlled drug release

Molecular Weight Effect on the Absorption, Charge Carrier Mobility, and Photovoltaic Performance of an Indacenodiselenophene-Based Ladder-Type Polymer

Selenium substitution on a ladder-type indacenodithiophene-based polymer (PIDT-DFBT) is investigated in order to reduce band gap, improve charge mobilities, and enhance the photovoltaic performance of the material. The new indacenodiselenophene-based polymer (PIDSe-DFBT) possessed improved absorption over its sulfur analogue in films, as well as substantially higher charge mobilities (0.15 and 0.064 cm2/(V s) hole and electron mobility, respectively, compared to 0.002 and 0.008 cm2/(V s) for PIDT-DFBT). The enhanced material properties led to an improved power conversion efficiency of 6.8% in photovoltaic cells, a 13% improvement over PIDT-DFBT-based devices. Furthermore, we examined the effect of molecular weight on the properties of PIDSe-DFBT and found not only a strong molecular weight dependence on mobilities, but also on the absorptivity of polymer films, with each 15 000 g/mol increase in weight, leading to a 25% increase in the absorptivity of the material. The molecular weight dependence of the material’s properties resulted in a significant difference in photovoltaic performance with the high-molecular-weight PIDSe-DFBT providing a higher photocurrent, fill factor, and efficiency due to its improved absorption and hole mobility. These results demonstrate the importance of achieving high molecular weight and the potential that selenium-containing ladder-type polymers have in the design of high-performance semiconducting polymers for organic photovoltaics (OPVs).

Selenium-Containing Polymers: Promising Biomaterials for Controlled Release and Enzyme Mimics

Although researchers have made great progress in the development of responsive polymeric materials for controlled drug release or diagnostics over the last 10 years, therapeutic results still lag behind expectations. The development of special materials that respond to physiological relevant concentrations, typically within the micromolar or nanomolar concentration regime, remains challenging. Therefore, researchers continue to pursue new biomaterials with unique properties and that respond to mild biochemical signals or biomarkers. Selenium is an essential element in human body with potential antioxidant properties. Because of selenium's electronegativity and atomic radius, selenium-containing compounds exhibit unique bond energy (C-Se bond 244 kJ mol⁻¹; Se-Se bond 172 kJ mol⁻¹). These values give the C-Se or Se-Se covalent bonds dynamic character and make them responsive to mild stimuli. Therefore, selenium-containing polymers can disassemble in response to changes under physiological relevant conditions. This property makes them a promising biomaterial for controlled release of drugs or synthetic enzyme mimics. Until recently, few researchers have looked at selenium-containing polymers as novel biomaterials. In this Account, we summarize our recent research on selenium-containing polymers and show their potential application as mild-responsive drug delivery vehicles and artificial enzymes. We begin by reviewing the current state of the art in the synthesis of selenium-containing main chain block copolymers. We highlight the dual redox and gamma-irradiation behaviors of diselenide-containing block copolymers assemblies, discussing the possibility of their use in a combination of chemotherapy and actinotherapy. We also describe the coordination of platinum with monoselenide containing block copolymers. Such structures offer the possibility of fabricating multidrug systems for cooperative chemotherapy. In addition, we summarize the methods for the covalent and noncovalent preparation of selenium-containing polymers with side chains, which highlight the opportunity to reversibly tune the amphiphilicity of selenium-containing polymers. Finally, we present strategies for the design of highly efficient selenium-containing dendritic polymers that can mimic enzymes. This field is still in its infancy period, and further research can only be limited by our imagination.

Single-Molecule Force Spectroscopy of Selenium-Containing Amphiphilic Block Copolymer: Toward Disassembling the Polymer Micelles

Selenium-containing polymers are a new type of responsive polymer material. Here, a selenium-containing amphiphilic block copolymer (PEG-PUSe-PEG) has been investigated using atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS). The deviation between force-extension curves of PEG-PUSe-PEG in water and in DMSO is found to be related to the disassembly of the micellar structures in water. SMFS experiments on PEG-PUSeox-PEG suggest that the change from selenide to oxidized selenone contributes significantly to the change in amphiphilicity, without obviously influencing the single-chain elasticity.