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1.
J Am Chem Soc ; 146(4): 2484-2493, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38229260

RESUMO

Organic cocrystals obtained from multicomponent self-assembly have garnered considerable attention due to their distinct phosphorescence properties and broad applications. Yet, there have been limited reports on cocrystal systems that showcase efficient deep-red to near-infrared (NIR) charge-transfer (CT) phosphorescence. Furthermore, effective strategies to modulate the emission pathways of both fluorescence and phosphorescence remain underexplored. In this work, we dedicated our work to four distinct self-assembled cocrystals called "pyrene box" cages using 1,3,6,8-pyrenetetrasulfonate anions (PTS4-), 4-iodoaniline (1), guanidinium (G+), diaminoguanidinium (A2G+), and hydrated K+ countercations. The binding of such cations to PTS4- platforms adaptively modulates their supramolecular stacking self-assembly with guest molecules 1, allowing to steer the fluorescence and phosphorescence pathways. Notably, the confinement of guest molecule 1 within "pyrene box" PTSK{1} and PTSG{1} cages leads to an efficient deep-red to NIR CT phosphorescence emission. The addition of fuming gases like triethylamine and HCl allows reversible pH modulations of guest binding, which in turn induce a reversible transition of the "pyrene box" cage between fluorescence and phosphorescence states. This capability was further illustrated through a proof-of-concept demonstration in shrimp freshness detection. Our findings not only lay a foundation for future supramolecular designs leveraging weak intermolecular host-guest interactions to engineer excited states in interacting chromophores but also broaden the prospective applications of room-temperature phosphorescence materials in food safety detection.

2.
Biomacromolecules ; 25(4): 2635-2644, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38478586

RESUMO

Developing nonconjugated materials with large Stokes shifts is highly desired. In this work, three kinds of hyperbranched aggregation-induced emission (AIE) polymers with tunable n/π electronic effects were synthesized. HBPSi-CBD contains alkenyl groups in the backbone and possesses a promoted n-π* transition and red-shifted emission wavelength with a large Stokes shift of 186 nm. Experiments and theoretical simulations confirmed that the planar π electrons in the backbone are responsible for the red-shifted emission due to the strong through-space n···π interactions and restricted backbone motions. Additionally, the designed HBPSi-CBD could be utilized as an ROS scavenger after coupling with l-methionine. The HBPSi-Met exhibits remarkable ROS scavenging properties with a scavenging capacity of 77%. This work not only gains further insight into the structure-property relationship of nonconjugated hyperbranched AIE polymers but also provides a promising ROS-scavenging biomaterial for the treatment of ROS-related diseases.


Assuntos
Elétrons , Polímeros , Espécies Reativas de Oxigênio , Materiais Biocompatíveis
3.
Biomacromolecules ; 24(4): 1888-1900, 2023 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-36988226

RESUMO

The design of tunable luminescent biomaterials with large Stokes shifts is usually pursued by a twisted intramolecular charge transfer (TICT) effect with switchable emission colors in response to various external stimuli. However, such a strategy is usually realized in conjugated molecules containing benzene or its derivatives and consequently suffers from poor biocompatibility. In this work, a hyperbranched polysiloxane (HBPSi)-based non-conjugated fluorescent polymer with TICT and aggregation-induced emission (AIE) features is developed, and its luminescent properties, fluorescence mechanism, and potential applications are investigated. Initially, the non-conjugated HBPSi exhibits remarkable AIE characteristics due to the formation of through-space conjugation. With the introduction of the sulfur atom, a non-conjugated D-A type AIE material, HBPSi-Cys, that exhibits a dual-state emission with a large Stokes shift of 213 nm, is obtained. The correlation of the lower-energy emission band with solvent polarity suggests the existence of the TICT state. TICT and AIE characteristics direct different properties of HBPSi-Cys, with TICT regulating solvatochromic emission wavelengths and AIE manipulating the emission intensity with a compensation effect. Density functional theory calculations reveal that the non-conjugated D-A structure in HBPSi-Cys was formed across the silicon bridge, with auxochromic sulfhydryl groups and adjacent amide groups as acceptor units and amine and hydroxyl groups as donor units. Additionally, the AIE-active HBPSi could be utilized as a fluorescent probe for the analysis of metal ions. After grafting the AS1411 aptamer to HBPSi-Cys as the recognition motif, HBPSi-Apt possesses excellent targeted bioimaging, drug loading, pH/GSH dual-responsive drug release, and visualized drug delivery performance. This work provides a new way to design functional AIE polymers with tunable optical properties, and the synthesized HBPSi-Cys shows great potential as a smart fluorescent biomaterial.


Assuntos
Polímeros , Silício , Polímeros/química , Liberação Controlada de Fármacos , Sistemas de Liberação de Medicamentos , Corantes Fluorescentes/química , Siloxanas
4.
Angew Chem Int Ed Engl ; 62(48): e202312571, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-37753802

RESUMO

Non-traditional fluorescent polymers have attracted significant attention for their excellent biocompatibility and diverse applications. However, designing and preparing non-traditional fluorescent polymers that simultaneously possess long emission wavelengths and long fluorescence lifetime remains challenging. In this study, a series of novel hyperbranched polyborosiloxanes (P1-P4) were synthesized. As the electron density increases on the monomer diol, the optimal emission wavelengths of the P1-P4 polymers gradually red-shift to 510, 570, 575, and 640 nm, respectively. In particular, P4 not only exhibits red emission but also demonstrates delayed fluorescence with a lifetime of 9.73 µs and the lowest critical cluster concentration (1.76 mg/mL). The experimental results and theoretical calculations revealed that the synergistic effect of dual heteroatom-induced electron delocalization and through-space O⋅⋅⋅O and O⋅⋅⋅N interaction was the key factor contributing to the red-light emission with delayed fluorescence. Additionally, these polymers showed excellent potential in dual-information encryption. This study provides a universal design strategy for the development of unconventional fluorescent polymers with both delayed fluorescence and long-wavelength emission.

5.
Carcinogenesis ; 43(5): 479-493, 2022 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-35134836

RESUMO

Human papillomavirus (HPV) E7 oncogene plays the most important role in cervical cancer. However, whether E7 oncoprotein is continuously expressed, associated with AKT(Ser473)/p-Src(Tyr527) signaling to trigger cervical carcinogenesis remains unclear. Here, we explored first if HPV16 E7 oncoprotein could be detected in clinical biopsies and is sustainedly expressed, and then investigated how this oncoprotein interacted with AKT(Ser473)/p-Src(Tyr527) signaling in cancer progression. We used ZHPV16E7384 affibody to detect E7 expression in HPV16-positive cervical cancer biopsies and animal tumors by immunohistochemistry (IHC). Results showed that ZHPV16E7384 affibody had intense and specific staining for E7 oncoprotein in the detected specimen. The E7 oncoprotein was continuously expressed to correspond with the development of precancerous lesions to invasive cervical cancer. IHC staining also revealed that AKT, p-AKT(Ser473), Src and p-Src(Tyr527) proteins were expressed in both patient biopsies and animal tumors, with the highest levels of p-AKT(Ser473)/p-Src(Tyr527) present in invasive cancer. Furthermore, siRNA experiments revealed that HPV16 E7 knockdown significantly impaired expression of p-AKT(Ser473)/p-Src(Tyr527) in both HPV16 E7-positive cancer cells and transformed cells. In addition, transient expression of HPV16 E7 protein promoted significantly expression of p-AKT(Ser473)/p-Src(Tyr527) in primary human keratinocytes. Finally, co-immunoprecipitation analysis proved that HPV 16 E7 protein interacted reciprocally with p-AKT(Ser473)/p-Src(Tyr527). In conclusion, we demonstrate that HPV16 E7 oncoprotein is continuously expressed to promote expression of p-AKT(Ser473)/p-Src(Tyr527) leading to drive the initiation and progression of cervical cancer. Our data provide a novel insight that HPV16 E7 activates p-AKT(Ser473)/p-Src(Tyr527) to establish a mechanistic link between the oncogene and the AKT/Src signaling to trigger cervical carcinogenesis.


Assuntos
Proteínas Oncogênicas Virais , Infecções por Papillomavirus , Lesões Pré-Cancerosas , Neoplasias do Colo do Útero , Animais , Carcinogênese , Feminino , Humanos , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/metabolismo , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/genética , Lesões Pré-Cancerosas/genética , Proteínas Proto-Oncogênicas c-akt/genética , Neoplasias do Colo do Útero/patologia
6.
J Clin Lab Anal ; 36(6): e24479, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35527696

RESUMO

BACKGROUND: SARS-CoV-2 has spread worldwide causing more than 400 million people with virus infections since early 2020. Currently, the existing vaccines targeting the spike glycoprotein (S protein) of SARS-CoV-2 are facing great challenge from the infection of SARS-CoV-2 virus and its multiple S protein variants. Thus, we need to develop a new generation of vaccines to prevent infection of the SARS-CoV-2 variants. Compared with the S protein, the nucleocapsid protein (N protein) of SARS-CoV-2 is more conservative and less mutations, which also plays a vital role in viral infection. Therefore, the N protein may have the great potential for developing new vaccines. METHODS: The N protein of SARS-CoV-2 was recombinantly expressed and purified in Escherichia coli. Western Blot and ELISA assays were used to demonstrate the immunoreactivity of the recombinant N protein with the serum of 22 COVID-19 patients. We investigated further the response of the specific serum antibodies and cytokine production in BALB/c mice immunized with recombinant N protein by Western Blot and ELISA. RESULTS: The N protein had good immunoreactivity and the production of IgG antibody against N protein in COVID-19 patients was tightly correlated with disease severity. Furthermore, the N protein was used to immunize BALB/c mice to have elicited strong immune responses. Not only high levels of IgG antibody, but also cytokine-IFN-γ were produced in the N protein-immunized mice. Importantly, the N protein immunization induced a high level of IgM antibody produced in the mice. CONCLUSION: SARS-CoV-2 N protein shows a great big bundle of potentiality for developing a new generation of vaccines in fighting infection of SARS-CoV-2 and its variants.


Assuntos
COVID-19 , Vacinas , Animais , Anticorpos Antivirais , COVID-19/prevenção & controle , Citocinas , Humanos , Imunoglobulina G , Camundongos , Camundongos Endogâmicos BALB C , Proteínas do Nucleocapsídeo , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/genética
7.
Angew Chem Int Ed Engl ; 61(29): e202204383, 2022 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-35499909

RESUMO

Non-conjugated fluorescent polymers have attracted great attention due to their excellent biocompatibility and environmental friendliness. However, it remains a huge challenge to obtain a polymer with high fluorescence quantum yield (QY) and multicolor emission simultaneously. Herein, we reported three kinds of nonaromatic hyperbranched polyborates (P1-P3) with multicolor emission, surprisingly, P2 also exhibits an unanticipated high QY (54.1 %). The natural bond orbital (NBO) analysis and density functional theory (DFT) calculation results revealed that the synergistic effect of rigid BO3 planar and flexible carbon chain, as well as the through-space dative bond in supramolecular aggregate, were the key factors contributing to the ultrahigh QY of P2. Moreover, the applications of P2 in Fe3+ ions detection and cell imaging were also investigated. This work provides a new perspective for designing non-conjugated fluorescent polymers with both high QY and multicolor emission.


Assuntos
Polímeros , Pontos Quânticos , Carbono/química , Fluorescência , Corantes Fluorescentes/química , Polímeros/química , Pontos Quânticos/química
8.
Acta Virol ; 65(2): 192-199, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34130470

RESUMO

We have previously reported that bovine papillomavirus type 1 (BPV1) can replicate its genome and produces infectious virus-like particles in short-term BPV1 virion-infected Sacharomyces cerevisiae (Zhao and Frazer, 2002). Here, we report viral RNA transcription and L1 capsid protein expression in long-term BPV1 virion-infected S. cerevisiae culture. Northern blot hybridization showed that viral RNA was detected in long-term BPV1-infected S. cerevisiae cultures (82-108 days). The levels of the viral RNA transcription varied significantly over the long time period, which showed active transcription at an early stage (Day 3 to Day 16), weak transcription at a middle stage (Day 23 to Day 45) and stable transcription at the late stage of culture (Day 55 to Day 82/85/95). Three major BPV1 transcripts of 4.3, 2.6 and 1.8 Kb were identified, with 4.3 Kb a minor transcript and the 1.8 Kb the most prominent transcript compared with the 2.6 Kb species. Immunoblotting showed that L1 capsid protein was expressed, with its variable amounts corresponding to the levels of RNA transcription over the time period. 35S-methionine/cysteine labeling and immunoprecipitation proved that the detected L1 protein was newly synthesized in BPV1-infected S. cerevisiae cultures. 33.3-54.2% of the cell colonies expressed L1 protein. Thus, the S. cerevisiae system, as a promising model, may be used not only for the study of virus like particle formation of BPV1 in vitro, but also for further functional analysis of individual viral genes in BPV1 life cycle. Keywords: BPV1; viral RNA transcription; expression of L1 capsid protein; virion-infected Saccharomyces cerevisiae.


Assuntos
Papillomavirus Bovino 1 , Papillomavirus Bovino 1/genética , Capsídeo , Proteínas do Capsídeo/genética , Saccharomyces cerevisiae/genética , Vírion
9.
Biomacromolecules ; 20(11): 4230-4240, 2019 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-31633916

RESUMO

Hyperbranched polysiloxane (HBPSi) is attracting increasing attention due to its intrinsic fluorescence and good biocompatibility. However, it is very challenging to explore its biological applications because of the low fluorescence intensity and quantum yield. Herein, we introduced rigid ß-cyclodextrin to the end of flexible polysiloxane chain to synthesize a novel fluorescent polymer (HBPSi-CD) and explore its biological applications. Results showed that the fluorescence intensity and quantum yield of HBPSi-CD, compared with HBPSi, were significantly enhanced. Theoretical calculations and transmission electron microscopy demonstrated that the synergy effect of intra/intermolecular hydrogen bonds and hydrophobic effect promoted the formation of large supramolecular self-assemblies and space electron delocalization systems, leading to intense fluorescence. Notably, the biocompatible HBPSi-CD not only lighted up mouse fibroblast cells, but also possessed high ibuprofen loading capacity (160 mg g-1) and superior pH-responsive drug release performance. This work promoted the development of biological applications of HBPSi.


Assuntos
Sistemas de Liberação de Medicamentos , Imagem Molecular/métodos , Siloxanas/química , beta-Ciclodextrinas/química , Animais , Materiais Biocompatíveis/química , Rastreamento de Células/métodos , Corantes Fluorescentes/química , Corantes Fluorescentes/farmacologia , Humanos , Ligação de Hidrogênio/efeitos dos fármacos , Camundongos , Siloxanas/farmacologia , beta-Ciclodextrinas/farmacologia
10.
Chemistry ; 23(17): 4037-4041, 2017 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-28177540

RESUMO

The complete structure of non-crystalline compounds can be determined by confining them in crystalline structures. The reduced motional degrees of freedom of encapsulated guests can be obtained through their anchoring to the host cages, which results in the reduction of a significant amount of disorder. The "pyrene box" cages that easily crystallize from aqueous solutions are recommended to achieve complete structure elucidation of compounds of biological interest. In this study, the "pyrene box" cages have been used for the in situ encapsulation of biogenic amines: histamine, dopamine, and serotonin. NMR spectroscopy illustrates that these systems are stable in aqueous solution. The X-ray single-crystal structure analysis reveals that the pyrene box/biogenic amine systems are stabilized through combined interactions, strongly contributing to in situ fixation and accurate determination of their crystal structures.

11.
Inorg Chem ; 53(12): 5950-60, 2014 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-24871052

RESUMO

On the basis of self-assembly from the divinylphenyl-modified Salen-type Schiff-base ligands H2L(1) (N,N'-bis(5-(3'-vinylphenyl)-3-methoxy-salicylidene)ethylene-1,2-diamine) or H2L(2) (N,N'-bis(5-(3'-vinylphenyl)-3-methoxy-salicylidene)phenylene-1,2-diamine) with Zn(OAc)2·2H2O and Ln(NO3)3·6H2O in the presence of pyridine (Py), two series of heterobinuclear Zn-Ln complexes [Zn(L(n))(Py)Ln(NO3)3] (n = 1, Ln = La, 1; Ln = Nd, 2; or Ln = Gd, 3 and n = 2, Ln = La, 4; Ln = Nd, 5; or Ln = Gd, 6) are obtained, respectively. Further, through the physical doping and the controlled copolymerization with methyl methacrylate (MMA), two kinds of PMMA-supported hybrid materials, doped PMMA/[Zn(L(n))(Py)Ln(NO3)3] and Wolf Type II Zn(2+)-Ln(3+)-containing metallopolymers Poly(MMA-co-[Zn(L(n))(Py)Ln(NO3)3]), are obtained, respectively. The result of their solid photophysical properties shows the strong and characteristic near-infrared (NIR) luminescent Nd(3+)-centered emissions for both PMMA/[Zn(L(n))(Py)Nd(NO3)3] and Poly(MMA-co-[Zn(L(n))(Py)Nd(NO3)3]), where ethylene-linked hybrid materials endow relatively higher intrinsic quantum yields due to the sensitization from both (1)LC and (3)LC of the chromorphore than those from only (1)LC in phenylene-linked hybrid materials, and the concentration self-quenching of Nd(3+)-based NIR luminescence could be effectively prevented for the copolymerized hybrid materials in comparison with the doped hybrid materials.

12.
Adv Sci (Weinh) ; 11(2): e2306350, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37933980

RESUMO

Degradation and reprocessing of thermoset polymers have long been intractable challenges to meet a sustainable future. Star strategies via dynamic cross-linking hydrogen bonds and/or covalent bonds can afford reprocessable thermosets, but often at the cost of properties or even their functions. Herein, a simple strategy coined as hyperbranched dynamic crosslinking networks (HDCNs) toward in-practice engineering a petroleum-based epoxy thermoset into degradable, reconfigurable, and multifunctional vitrimer is provided. The special characteristics of HDCNs involve spatially topological crosslinks for solvent adaption and multi-dynamic linkages for reversible behaviors. The resulting vitrimer displays mild room-temperature degradation to dimethylacetamide and can realize the cycling of carbon fiber and epoxy powder from composite. Besides, they have supra toughness and high flexural modulus, high transparency as well as fire-retardancy surpassing their original thermoset. Notably, it is noted in a chance-following that ethanol molecule can induce the reconstruction of vitrimer network by ester-exchange, converting a stiff vitrimer into elastomeric feature, and such material records an ultrahigh modulus (5.45 GPa) at -150 °C for their ultralow-temperature condition uses. This is shaping up to be a potentially sustainable advanced material to address the post-consumer thermoset waste, and also provide a newly crosslinked mode for the designs of high-performance polymer.

13.
ACS Appl Mater Interfaces ; 15(13): 17211-17221, 2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-36859768

RESUMO

Lanthanide-based (Ln3+) luminescent materials are ideal candidates for use in fluorescence intracellular temperature sensing. However, it remains a great challenge to obtain a Ln3+-ratiometric fluorescence thermometer with high sensitivity and quantum yield in an aqueous environment. Herein, a cationic Eu3+-metallopolymer was synthesized via the coordination of Eu(TTA)3·2H2O with an AIE active amphipathic polymer backbone that contains APTMA ((3-acrylamidopropyl) trimethylammonium) and NIPAM (N-isopropylacrylamide) units, which can self-assemble into nanoparticles in water solution with APTMA and NIPAM as the hydrophilic shell. This polymer exhibited highly efficient dual-emissive white-light emission (Φ = 34.3%). Particularly, when the temperature rises, the NIPAM units will transform from hydrophilic to hydrophobic in the spherical core of the nanoparticle, while the VTPE units are moved from inside the nanoparticle to the shell, activating its nonradiative transition channel and thereby decreasing its energy transfer to Eu3+ centers, endowing the Eu3+-metallopolymer with an extremely high temperature sensing sensitivity within the physiological temperature range. Finally, the real-time monitoring of the intracellular temperature variation is further conducted.

14.
Chem Commun (Camb) ; 59(100): 14823-14826, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38009240

RESUMO

By leveraging natural saturated fatty acids with distinct melting points and swift reversible phase transitions, we correlated external thermal cues to monomer and excimer emissions of difluoroboron ß-diketonate fluorophores. This integration yielded a ratiometric fluorescent thermometer showcasing unparalleled sensitivity and thermochromism in the physiological temperature range.

15.
Microbiol Spectr ; 11(1): e0356222, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36511681

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been an unprecedented public health disaster in human history, and its spike (S) protein is the major target for vaccines and antiviral drug development. Although widespread vaccination has been well established, the viral gene is prone to rapid mutation, resulting in multiple global spread waves. Therefore, specific antivirals are needed urgently, especially those against variants. In this study, the domain of the receptor binding motif (RBM) and fusion peptide (FP) (amino acids [aa] 436 to 829; denoted RBMFP) of the SARS-CoV-2 S protein was expressed as a recombinant RBMFP protein in Escherichia coli and identified as being immunogenic and antigenically active. Then, the RBMFP proteins were used for phage display to screen the novel affibody. After prokaryotic expression and selection, four novel affibody molecules (Z14, Z149, Z171, and Z327) were obtained. Through surface plasmon resonance (SPR) and pseudovirus neutralization assay, we showed that affibody molecules specifically bind to the RBMFP protein with high affinity and neutralize against SARS-CoV-2 pseudovirus infection. Especially, Z14 and Z171 displayed strong neutralizing activities against Delta and Omicron variants. Molecular docking predicted that affibody molecule interaction sites with RBM overlapped with ACE2. Thus, the novel affibody molecules could be further developed as specific neutralization agents against SARS-CoV-2 variants. IMPORTANCE SARS-CoV-2 and its variants are threatening the whole world. Although a full dose of vaccine injection showed great preventive effects and monoclonal antibody reagents have also been used for a specific treatment, the global pandemic persists. So, developing new vaccines and specific agents are needed urgently. In this work, we expressed the recombinant RBMFP protein as an antigen, identified its antigenicity, and used it as an antigen for affibody phage-display selection. After the prokaryotic expression, the specific affibody molecules were obtained and tested for pseudovirus neutralization. Results showed that the serum antibody induced by RBMFP neutralized Omicron variants. The screened affibody molecules specifically bound the RBMFP of SARS-CoV-2 with high affinity and neutralized the Delta and Omicron pseudovirus in vitro. So, the RBMFP induced serum provides neutralizing effects against pseudovirus in vitro, and the affibodies have the potential to be developed into specific prophylactic agents for SARS-CoV-2 and its variants.


Assuntos
COVID-19 , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Humanos , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Simulação de Acoplamento Molecular , Testes de Neutralização/métodos , Proteínas Recombinantes , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia
16.
Inorg Chem ; 51(21): 11377-86, 2012 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-23043380

RESUMO

Unique homoleptic cyclic tetranuclear Ln(4)(Salen)(4) complexes [Ln(4)(L)(2)(HL)(2)(µ(3)-OH)(2)Cl(2)]·2Cl (Ln = Nd, 1; Ln = Yb, 2; Ln = Er, 3; Ln = Gd, 4) or Ln(4)(Salen)(2) complexes [Ln(4)(L)(2)(µ(3)-OH)(2)(OAc)(6)] (Ln = Nd, 5; Ln = Yb, 6; Ln = Er, 7; Ln = Gd, 8) have been self-assembled from the reaction of the hexadentate Salen-type Schiff-base ligand H(2)L with LnCl(3)·6H(2)O or Ln(OAc)(6)·6H(2)O (Ln = Nd, Yb, Er, or Gd), respectively (H(2)L: N,N'-bis(salicylidene)cyclohexane-1,2-diamine). The result of their photophysical properties shows that the strong and characteristic NIR luminescence for complexes 1-2 and 5-6 with emissive lifetimes in microsecond ranges are observed, and the sensitization arises from the excited state (both (1)LC and (3)LC) of the hexadentate Salen-type Schiff-base ligand with the flexible linker. Temperature dependence (1.8-300 K) magnetic susceptibility studies of the eight complexes suggest the presence of an antiferromagnetic interaction between the Ln(3+) ions.


Assuntos
Ânions/química , Etilenodiaminas/química , Elementos da Série dos Lantanídeos/química , Substâncias Luminescentes/química , Imãs/química , Ânions/síntese química , Cicloexilaminas/síntese química , Cicloexilaminas/química , Etilenodiaminas/síntese química , Elementos da Série dos Lantanídeos/síntese química , Ligantes , Substâncias Luminescentes/síntese química , Modelos Moleculares , Bases de Schiff/síntese química , Bases de Schiff/química
17.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 3): o852, 2012 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22412710

RESUMO

The title compound, C(20)H(15)BrN(2)O(2), crystallized with three independent molecules in the asymmetric unit. Intramolecular O-H⋯N hydrogen bonds induce coplanarity of the substituted benzene ring and the benzimidazole ring, with mean deviations from the planes of 0.0931 (10), 0.0448 (10) and 0.0083 (11) Šin the three mol-ecules.

18.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 7): o2040, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22807865

RESUMO

The organic molecule of the title hydrate, C(15)H(13)BrN(2)O(4)·H(2)O, is roughly planar, with a mean deviation of 0.0939 (2) Å. The dihedral angle between the two aromatic rings is 8.2 (3)°. Intra-molecular O-H⋯N and O-H⋯O hydrogen bonds are observed. In the crystal, N-H⋯O(water) and O(water)-H⋯O hydrogen bonds lead to a three-dimensional network.

19.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 9): m1216, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22969498

RESUMO

The title compound, [Cu(2)(C(15)H(11)BrN(2)O(4))(2)(C(3)H(7)NO)(2)], is derived from the reaction of N'-(5-bromo-2-hy-droxy-3-meth-oxy-benzyl-idene)-2-hy-droxy-benzohydrazide and copper nitrate in a dimethyl-formamide solution in the presence of sodium hydroxide. The compound can be regarded as a binuclear centrosymmetric complex. In the crystal, the Cu(II) atom is fivefold surrounded and adopts a distorted square-pyramidal coordination environment. An intra-molecular O-H⋯N hydrogen bond stabilizes the mol-ecular conformation.

20.
Biomater Adv ; 137: 212848, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35929243

RESUMO

Hyperbranched polymers hold great promise in nanomedicine for their controlled chemical structures, sizes, multiple terminal groups and enhanced stability than linear amphiphilic polymer assemblies. However, the rational design of hyperbranched polymer-based nanomedicine with low toxic materials, selective cellular uptake, controlled drug release, as well as real-time drug release tracking remains challenging. In this work, a hyperbranched multifunctional prodrug HBPSi-SS-HCPT is constructed basing on the nonconventional aggregation-induced emission (AIE) featured hyperbranched polysiloxanes (HBPSi). The HBPSi is a biocompatible AIE macromolecule devoid of conjugates, showing a high quantum yield of 17.88% and low cytotoxicity. By covalently grafting the anticancer drug, 10-hydroxycamptothecin (HCPT), to the HBPSi through 3,3'-dithiodipropionic acid, HBPSi-SS-HCPT is obtained. The HBPSis demonstrate obvious AIE features and it turned to aggregation-caused quenching (ACQ) after grafting HCPT owing to the FRET behavior between HBPSi and HCPT in HBPSi-SS-HCPT. In addition to on-demand HCPT release in response to changes in environmental pH and glutathione, a series of in vitro and in vivo studies revealed that HBPSi-SS-HCPT exhibits enhanced accumulation in tumor tissues through the enhanced permeation and retention (EPR) effect and preferential cancer cell uptake by charge reversal, thus resulting in apoptotic cell death subsequently. This newly developed multifunctional HBPSi-SS-HCPT prodrug provides a biocompatible strategy for controlled drug delivery, preferential cancer cell uptake, on-demand drug release and enhanced antitumor efficacy.


Assuntos
Pró-Fármacos , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Polímeros/química , Pró-Fármacos/farmacologia , Siloxanas
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