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Light-responsive nanoparticles based on new polycarbonate polymers as innovative drug delivery systems for photosensitizers in PDT
摘要： Nanoparticles based on biodegradable polymers are well-known as approved carrier systems for a diversity of drugs. Despite their advantages, such as the option of an active drug targeting or the physicochemical protection of instable payloads, the controlled drug release often underlies intra- and interindividual influences and is therefore difficult to predict. To circumvent this limitation, the release behavior can be optimized using light-responsive materials for the nanoparticle preparation. The resulting light-responsive nanoparticles are able to release the embedded drug after an external light-stimulus, thereby increasing efficacy and safety of the therapy. In the present study light-responsive self-immolative polymers were used for the nanoparticle manufacturing. Light-responsive polycarbonates (LrPC) as well as PEGylated LrPC (LrPC-PEG) were synthesized via ring-opening polymerization of trimethylene carbonate-based monomers and fully physico-chemically characterized. Light-responsive nano formulations were obtained by blending LrPC or (LrPC-PEG) with the FDA-approved polymer poly(lactic-co-glycolic-acid) (PLGA). The nanoparticles were loaded with the photosensitizer 5,10,15,20-tetrakis(m-hydroxyphenyl)chlorin (mTHPC). The light-induced nanoparticle degradation was analyzed as well as the drug release behavior with and without illumination. Furthermore, biological safety of the degradation products was investigated in an in vitro cell culture study.
关键词： light-responsive polymers,Nanoparticles,intestinal cancer,photodynamic therapy,poly(lactic-co-glycolic acid)
更新于2025-09-23 15:22:29
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One-dimensional coordination polymers based on a new 3-position substituted imidazo[1,2-a]pyridine ligand: Crystal structures, photoluminescent and magnetic properties
摘要： A new 3-position substituted imidazo[1,2-a]pyridine ligand, namely, 5-(2-chloroimidazo[1,2-a]pyridine-3-carboxamido) isophthalic acid (H2L) was synthesized and characterized by 1H NMR spectroscopy. Based on this ligand, three isostructural one-dimensional coordination polymers, [ML(H2O)2]n (M = Zn (1), Ni (2) and Co (3)) were synthesized under the solvothermal conditions, and structurally characterized by single crystal X-ray diffraction, infrared spectroscopy, powder X-ray diffraction and elemental analyses. The coordination polymer 1 reveals similar photoluminescent spectrum to H2L ligand, but possesses the enhanced phosphorescent emission and higher phosphorescent quantum yield, compared to H2L ligand. Furthermore, the magnetic properties of coordination polymers 2 and 3 have been investigated, the results show there are antiferromagnetic interactions between the NiII ions or CoII ions in 2 or 3.
关键词： Photoluminescence,Coordination polymers,Imidazo[1,2-a]pyridine,X-ray structures,Magnetic properties
更新于2025-09-23 15:22:29
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Electrochromic behavior of films and ?smart windows? prototypes based on π-conjugated and non–conjugated poly(pyridinium triflate)s
摘要： This study is focused on two electrochromic poly(pyridinium triflate)s. They are aromatic rigid-rod polymer PV1 and PV12 containing alkyl linkages. Electrochromic behavior of both polymers was comparatively investigated by employing a three-electrode cell and ?smart windows? prototypes. The electrochromic properties of polymer films were examined by electrochemical and spectroelectrochemical methods. Polymers with π-conjugate and non-conjugate structure demonstrate reversible redox process accompanied by a reversible color change both in three-electrode cell and electrochromic device (ECD). In general, introduction of the non-conjugated spacers to the PV12 backbone structure leads to deterioration in the optical contrast and switching time in comparison with π-conjugated PV1. The same effect was also detected for ECD. The reason behind this is thought to be a complication of electron transport in the system due to non-conjugated PV12 backbone structure.
关键词： Electrochromic polymers,Poly(pyridinium) salts,Conjugated polymer,Cyclic voltammetry,Electrochromism
更新于2025-09-23 15:22:29
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The Sonogel-Carbon-PEDOT Material: An Innovative Bulk Material for Sensor Devices
摘要： The synthesis of a new bulk material based on silicon oxide and poly-(3,4-ethylenedioxythiophene) (PEDOT), the Sonogel-Carbon-PEDOT material, is carried out. The main purpose is to obtain a bare conducting material, aided by statistical experimental design, able to be used as transducer for electrochemical devices. This new material tries also to solve out the degradation and fouling drawbacks related to PEDOT-based layer devices by simply polishing its surface in a gently way. The resulting Sonogel-Carbon-PEDOT material shows excellent electrochemical properties, renewable surface and stability by using simple, low cost, and versatile synthesis method. As far as we are concerned, this is the first time that this kind of bulk material is reported. The resulting material was characterized by different techniques: SEM, EDS and Raman spectroscopy. Sonogel-Carbon-PEDOT was also electrochemically characterized for the assessment of the electrochemical performance of the resulting sensor device. Ascorbic acid was selected as reference analyte, obtaining good sensitivity and limit of detection: 319.8 μA mM-1cm-2 and 6.42 μM, respectively, in the concentration range 0.01–3.45 mM. Furthermore, repeatability and reproducibility studies (RSD<3%), were also very satisfactory. Finally, the Sonogel-Carbon-PEDOT sensor was successfully applied to the determination of ascorbic acid in a pharmaceutical formulation and biological samples, obtaining good recovery percentage (95–105%).
关键词： electrochemical properties,sensor devices,Sonogel-Carbon-PEDOT,conducting polymers,ascorbic acid
更新于2025-09-23 15:22:29
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Effects on optoelectronic performances of EDOT end-capped oligomers and electrochromic polymers by varying thienothiophene cores
摘要： Four 3,4-ethylenedoxythiophene (EDOT) end-capped oligomers employing single bond, EDOT, thieno[3,2-b]thiophene (TT) and dithieno[3,4-b;3′,4′-d]thiophene (DTT) units as bridge cores were synthesized and their polymers have been grown electrochemically. To reveal the relationship of structure-performance, the physicochemical properties, energy gaps, micromorphology, and photoelectrochemical behaviors of the oligomers or their polymers were systematically studied. These oligomers with planar rigid structures exhibit gradually narrowed molecular band gaps benefiting from their extended molecular conjugative degrees. These polymers present high electrochromic performances such as the higher optical contrast (59.61%) and coloring efficiency (288.37 cm2 C–1), excellent stability and colour persistence. As a result, increasing cofacial conjugation degrees via integration of TT or DTT into polymer backbone is an efficient method to encourage the intermolecular π-interaction, which brings broad and strong absorption and promote the carriers rapidly transport in polymer backbones to enhance the photoelectric performances. This study will provide promising electrochromic polymers for display applications.
关键词： thienothiophene,electrochromism,EDOT,conjugated polymers,electrosynthesis
更新于2025-09-23 15:22:29
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Ordered assemblies of Fe3O4 and a donor-acceptor-type π-conjugated polymer in nanoparticles for enhanced photoacoustic and magnetic effects
摘要： We report that the ordered structure in the assemblies of iron oxide nanoparticles in conjugated polymer nanoparticles is the key to achieve better properties to realize multimodal theranostic agents for magnetic resonance and photoacoustic imaging. Hybrid nanoparticles of a conjugated polymer (PCPDTBT), a phospholipid (D8PE) with a primary amine polar head, and iron oxide (Fe3O4) nanoparticles were prepared by a phase-separated film shattering process by varying the iron oxide concentration while maintaining a fixed mixing ratio of PCPDTBT and D8PE. Notably, the hybrid nanoparticles assembled at a molar mixing ratio of 1:1:0.8 (PCPDTBT/D8PE/Fe3O4) exhibited the shortest transversal relaxation time, T2, and a photoacoustic signal 22 times higher than that obtained at the 1:1:0 mixing ratio. Structural analysis by X-ray diffraction together with the measurements of energy transfer by transient absorption spectroscopy confirmed that the structural ordering of these hybrid nanoparticles was responsible for their enhanced photoacoustic and magnetic properties.
关键词： Conjugated polymers,Photoacoustic imaging,Magnetic resonance imaging,Iron oxides,Hybrid nanoparticles
更新于2025-09-23 15:22:29
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Long-Term Stability of Two Thermoplastic Polymers Modified with Silver Nanoparticles
摘要： The aim of this study was to investigate the mechanical properties of polymeric composites prepared via extrusion and injection moulding. Four stable thermoplastic polymers were used as composites matrices (two kinds of polymethyl methacrylate and two kinds of co-polymer acrylonitrile-butadiene-styrene). Silver nanoparticles AgNPs were used as a modifying phase. Mechanical properties of testes materials were determined during the uniaxial stretching. Surface properties such as roughness and contact angle were also evaluated. The materials’ stability was assessed using scanning electron microscopy and non-destructive ultrasonic testing. All measurements were carried out at time intervals, determining both the initial parameters and after 6 and 12 months of incubation in deionized water. The obtained results proved that neither the preparation technology nor the amount of the modi?er adversely affect the mechanical properties of the tested composites. The incorporated modi?er does not change the surface properties signi?cantly. The studies conducted after the materials’ incubation in water indicate their stability.
关键词： biomaterials,silver nanoparticles,biostable polymers
更新于2025-09-23 15:22:29
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Low-Threshold-Voltage and Electrically Switchable Polarization-Selective Scattering Mode Liquid Crystal Light Shutters
摘要： Low-threshold-voltage (Vth) and electrically switchable, polarization-selective scattering mode light shutters (PSMLSs) using polymer-dispersed liquid crystals (PDLCs) are demonstrated in this work. The optimized weight ratio of the nematic liquid crystals (LCs) to the adopted monomer (NBA107, Norland Optics) in the low-Vth PDLCs based on NBA107 is 7:3, [7:3]-PDLCsNBA107. The properties of the low-Vth PDLCsNBA107, such as light-scattering performance, initial transmission, Vth, and droplet size were investigated. Experiment results show that the surface anchoring (threshold-voltage) of NBA107 is weaker (lower) than or equal to that of the common NOA65. The cost is that the response time of the proposed PDLCsNBA107 is relatively long. A method to reduce the decay time, which can be applied to all other PDLC devices, will be elucidated. In addition to the low Vth of the proposed PDLCsNBA107, the operation voltage (~6 Vrms) to approach the maximum transmission is relatively low in a 7 μm-thick PDLCsNBA107 cell. Moreover, the polarization-selective light-scattering performances of the proposed PSMLSs based on the [7:3]-PDLCsNBA107, mainly driven by in-plane and vertical fields, are also demonstrated.
关键词： scattering,liquid crystals,polarization,polymers
更新于2025-09-23 15:22:29
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Electroluminochromic Materials: From Molecules to Polymers
摘要： Electroluminochromism is an interesting property found in certain classes of molecules and polymers whose photoluminescence can be modulated through the application of an external electrical bias. Unlike electrochromic materials, electroluminochromic counterparts and their applications are comparatively fewer in quantity and are less established. Nonetheless, there prevails an increasing interest in this class of electro-active materials due to their potential applications in optoelectronics, such as smart-displays, and chemical and biological sensing. This review seeks to showcase the different classes of electroluminochromic materials with focus on (i) organic molecules, (ii) transition metal complexes, and (iii) organic polymers. The mechanisms and electroluminochromic performance of these classes of materials are summarized. This review should allow scientists to have a better and deeper understanding of materials design strategies and, more importantly, structure-property relationships and, thus, develops electroluminochromic materials with desired performance in the future.
关键词： metal complexes,electroluminochromic,electrochromic,electrofluorochromic,polymers
更新于2025-09-23 15:22:29
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Synthesis of High Performance Cyclic Olefin Polymers (COPs) with Ester Group via Ring-Opening Metathesis Polymerization
摘要： Novel ester group functionalized cyclic olefin polymers (COPs) with high glass transition temperature, high transparency, good mechanical performance and excellent film forming ability have been achieved in this work via efficient ring-opening metathesis copolymerization of exo-1,4,4a,9,9a,10-hexahydro-9,10(1′,2′)-benzeno-l,4-methanoanthracene (HBM) and comonomers (5-norbornene-2-yl methylacetate (NMA), 5-norbornene-2-yl methyl 2-ethylhexanoate (NME) or 5-norbornene-2-yl methyldodecanoate (NMD)) utilizing the Grubbs first generation catalyst, Ru(CHPh)(Cl)2(PCy3)2 (Cy = cyclohexyl, G1), followed by hydrogenation of double bonds in the main chain. The fully hydrogenated copolymers were characterized by nuclear magnetic resonance, FT-IR spectroscopy analysis, gel permeation chromatography, and thermo gravimetric analysis. Differential scanning calorimetry curves showed that the glass transition temperatures (Tg) linearly decreased with the increasing of comonomers content, which was easily controlled by changing feed ratios of HBM and comonomers. Static water contact angles tests indicate that hydrophilicity of copolymers can also be modulated by changing the comonomers incorporation. Additionally, the mechanical performances of copolymers were also investigated.
关键词： dimensional stability,optical materials,COPs (cyclic olefin polymers),ROMP (ring-opening metathesis polymerization),hydrophilicity
更新于2025-09-23 15:22:29