1
|
Manjarres AM, Albers A, Fernández G. Photoregulated Supramolecular Polymerization through Halogen Bonding. Angew Chem Int Ed Engl 2024:e202419720. [PMID: 39485369 DOI: 10.1002/anie.202419720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2024] [Revised: 10/29/2024] [Accepted: 10/31/2024] [Indexed: 11/03/2024]
Abstract
Supramolecular polymers are able to change their structure, morphology and function in response to external stimuli. However, controlling the independence of stimuli-responses in these systems is challenging. Herein, we exploit halogen bonding (XB) as a reversible network element to regulate the photoresponsive and adaptive behavior of supramolecular polymers. To this end, we have designed a two-component system comprising an amphiphilic XB acceptor with the ability to self-assemble in aqueous media (OPE-Py) and a molecule with a dual photoresponsive and XB donor function [(E)-Azo-I]. OPE-Py self-assembles in aqueous media into supramolecular polymers, which transform into nanoparticle assemblies upon co-assembly with (E)-Azo-I. Interestingly, a third type of assembly (2D sheets) is obtained if OPE-Py is treated with (E)-Azo-I and exposed to photoirradiation. At ambient conditions, both nanoparticles and 2D sheets remain invariant over time. However, heating dissociates the XB interactions present in both assemblies, resulting in their transformation to the original fiber-like morphology of OPE-Py. Thus, breaking the communication between self-assembly and the stimuli-responses upon heating restores the original state of the system, drawing parallels to feedback loops in programming language. This work broadens the still limited scope of XB in solution assemblies and paves the way for multifunctional adaptive supramolecular systems.
Collapse
|
2
|
Veedu RM, Fernández Z, Bäumer N, Albers A, Fernández G. Pathway-dependent supramolecular polymerization by planarity breaking. Chem Sci 2024; 15:10745-10752. [PMID: 39027305 PMCID: PMC11253169 DOI: 10.1039/d4sc02499k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Accepted: 06/04/2024] [Indexed: 07/20/2024] Open
Abstract
In controlled supramolecular polymerization, planar π-conjugated scaffolds are commonly used to predictably regulate stacking interactions, with various assembly pathways arising from competing interactions involving side groups. However, the extent to which the nature of the chromophore itself (planar vs. non-planar) affects pathway complexity requires clarification. To address this question, we herein designed a new BOPHY dye 2, where two oppositely oriented BF2 groups induce a disruption of planarity, and compared its supramolecular polymerization in non-polar media with that of a previously reported planar BODIPY 1 bearing identical substituents. The slightly non-planar structure of the BOPHY dye 2, as evident in previously reported X-ray structures, together with the additional out-of-plane BF2 group, allow for more diverse stacking possibilities leading to two fiber-like assemblies (kinetic 2A and thermodynamic 2B), in contrast to the single assembly previously observed for BODIPY 1. The impact of the less rigid, preorganized BOPHY core compared to the planar BODIPY counterpart is also reflected in the stronger tendency of the former to form anisotropic assemblies as a result of more favorable hydrogen bonding arrays. The structural versatility of the BOPHY core ultimately enables two stable packing arrangements: a kinetically controlled antiparallel face-to-face stacking (2A), and a thermodynamically controlled parallel slipped packing (2B) stabilized by (BF2) F⋯H (meso) interactions. Our findings underscore the significance of planarity breaking and out-of-plane substituents on chromophores as design elements in controlled supramolecular polymerization.
Collapse
|
3
|
Cherid C, Baghdadli A, Wall M, Mayo NE, Berry G, Harvey EJ, Albers A, Bergeron SG, Morin SN. Current level of technology use, health and eHealth literacy in older Canadians with a recent fracture-a survey in orthopedic clinics. Osteoporos Int 2020; 31:1333-1340. [PMID: 32112118 DOI: 10.1007/s00198-020-05359-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 02/19/2020] [Indexed: 12/20/2022]
Abstract
UNLABELLED Among older adults who have recently sustained a fracture, there is substantial adoption of mobile technology. Furthermore, health and eHealth literacy level reported by participants supports the development of interactive eHealth interventions toward fostering better patient engagement in skeletal health management. INTRODUCTION Electronic health resources are increasingly used in the self-management of medical conditions. We aimed to identify the current level of technology adoption, health, and eHealth literacy among older adults with a recent fracture, to determine if the use of electronic interventions would be feasible and acceptable in this population. METHODS Adults ≥ 50 years with recent fractures were invited to complete a self-administered survey composed of 21 questions, including an 8-item perceived eHealth literacy scale. RESULTS A total of 401 participants completed the survey (women, 64%; ≥ 65 years, 59%; university education, 32%). Most participants reported no difficulty in reading printed health material (67%) and felt confident in filling out medical forms (65%). Younger age and higher levels of education were associated with higher health literacy. Most respondents (81%) owned at least one mobile device (smartphone, 49%; tablet, 45%). eHEALS scores were similar among men (29, IQR 24-32) and women (29, IQR 25-33), and between younger age group categories (50-64 years, 30; IQR 26-33; and 65-74 years, 29; IQR 25-32), but lower in the oldest age group (≥ 75 years, 24; IQR 21-29; p < 0.05). Compared with the youngest group, those ≥ 75 years had higher odds of an eHEALS < 26 (odds ratio, 4.2; 95% confidence interval 2.0-8.9) after adjusting for sex and education level. CONCLUSION There is significant adoption of mobile technology among older adults. Health and eHealth literacy reported by this study population supports the development of interactive eHealth interventions toward fostering better patient engagement in skeletal health management.
Collapse
|
4
|
Klinghammer K, Otto R, Raguse J, Albers A, Fichtner I, Keilholz U, Hoffmann J. Molecular subtypes of head and neck cancer predict response to cetuximab treatment. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)32744-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
5
|
Kowalska JK, Hahn AW, Albers A, Schiewer CE, Bjornsson R, Lima FA, Meyer F, DeBeer S. X-ray Absorption and Emission Spectroscopic Studies of [L2Fe2S2](n) Model Complexes: Implications for the Experimental Evaluation of Redox States in Iron-Sulfur Clusters. Inorg Chem 2016; 55:4485-97. [PMID: 27097289 PMCID: PMC5108557 DOI: 10.1021/acs.inorgchem.6b00295] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Herein, a systematic study of [L2Fe2S2](n) model complexes (where L = bis(benzimidazolato) and n = 2-, 3-, 4-) has been carried out using iron and sulfur K-edge X-ray absorption (XAS) and iron Kβ and valence-to-core X-ray emission spectroscopies (XES). These data are used as a test set to evaluate the relative strengths and weaknesses of X-ray core level spectroscopies in assessing redox changes in iron-sulfur clusters. The results are correlated to density functional theory (DFT) calculations of the spectra in order to further support the quantitative information that can be extracted from the experimental data. It is demonstrated that due to canceling effects of covalency and spin state, the information that can be extracted from Fe Kβ XES mainlines is limited. However, a careful analysis of the Fe K-edge XAS data shows that localized valence vs delocalized valence species may be differentiated on the basis of the pre-edge and K-edge energies. These findings are then applied to existing literature Fe K-edge XAS data on the iron protein, P-cluster, and FeMoco sites of nitrogenase. The ability to assess the extent of delocalization in the iron protein vs the P-cluster is highlighted. In addition, possible charge states for FeMoco on the basis of Fe K-edge XAS data are discussed. This study provides an important reference for future X-ray spectroscopic studies of iron-sulfur clusters.
Collapse
|
6
|
Jahreiß L, Zerkowitz P, Albers A. Ungewöhnliche Komplikation eines gewöhnlichen Infekts der oberen Atemwege. Laryngorhinootologie 2015; 94:461-3. [DOI: 10.1055/s-0034-1396856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
7
|
Tinhofer I, Jöhrens K, Keilholz U, Kaufmann A, Lehmann A, Weichert W, Stenzinger A, Stromberger C, Klinghammer K, Becker ET, Dommerich S, Stölzel K, Hofmann V, Hildebrandt B, Moser L, Ervens J, Böttcher A, Albers A, Stabenow R, Reinecke A, Budach V, Hoffmeister B, Raguse J. Contribution of human papilloma virus to the incidence of squamous cell carcinoma of the head and neck in a European population with high smoking prevalence. Eur J Cancer 2015; 51:514-521. [DOI: 10.1016/j.ejca.2014.12.018] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 12/20/2014] [Indexed: 11/24/2022]
|
8
|
Drechsler S, Burkardt N, Albers A, Butenko V, Walter B. Erhebung der Bedarfssituation und Herausforderungen der Normung und Standardisierung Vom Maschinen- und Anlagenbau bis zur Bioproduktion. CHEM-ING-TECH 2014. [DOI: 10.1002/cite.201450668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
9
|
Routy B, Albers A, Carli A, Harvey E, Seguin C. C0173: Treatment with Acetylsalicylic Acid (Aspirin) Prevents Short-To-Mid Term Radiographic Progression of Non-Traumatic Osteonecrosis of the Femoral Head. Thromb Res 2014. [DOI: 10.1016/s0049-3848(14)50171-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
10
|
Albers A, Demeshko S, Dechert S, Saouma CT, Mayer JM, Meyer F. Fast proton-coupled electron transfer observed for a high-fidelity structural and functional [2Fe-2S] Rieske model. J Am Chem Soc 2014; 136:3946-54. [PMID: 24506804 PMCID: PMC3985845 DOI: 10.1021/ja412449v] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
![]()
Rieske cofactors
have a [2Fe–2S] cluster with unique {His2Cys2} ligation and distinct Fe subsites. The histidine
ligands are functionally relevant, since they allow for coupling of
electron and proton transfer (PCET) during quinol oxidation in respiratory
and photosynthetic ET chains. Here we present the highest fidelity
synthetic analogue for the Rieske [2Fe–2S] cluster reported
so far. This synthetic analogue 5x– emulates the heteroleptic {His2Cys2} ligation of the [2Fe–2S] core, and it also serves
as a functional model that undergoes fast concerted proton and electron
transfer (CPET) upon reaction of the mixed-valent (ferrous/ferric)
protonated 5H2– with TEMPO. The thermodynamics
of the PCET square scheme for 5x– have been determined, and three species (diferric 52–, protonated diferric 5H–, and mixed-valent 53–) have been characterized by X-ray diffraction. pKa values for 5H– and 5H2– differ by about 4 units, and the reduction
potential of 5H– is shifted anodically
by about +230 mV compared to that of 52–. While the N–H bond dissociation free energy of 5H2– (60.2 ± 0.5 kcal mol–1) and the free energy, ΔG°CPET, of its reaction with TEMPO (−6.3 kcal mol–1) are similar to values recently reported for a homoleptic {N2/N2}-coordinated [2Fe–2S] cluster, CPET
is significantly faster for 5H2– with
biomimetic {N2/S2} ligation (k = (9.5 ± 1.2) × 104 M–1 s–1, ΔH‡ = 8.7
± 1.0 kJ mol–1, ΔS‡ = −120 ± 40 J mol–1 K–1, and ΔG‡ = 43.8 ± 0.3 kJ mol–1 at 293 K). These parameters,
and the comparison with homoleptic analogues, provide important information
and new perspectives for the mechanistic understanding of the biological
Rieske cofactor.
Collapse
|
11
|
Albers A, Bayer T, Demeshko S, Dechert S, Meyer F. A Functional Model for the Rieske Center: Full Characterization of a Biomimetic N-Ligated [2Fe-2S] Cluster in Different Protonation States. Chemistry 2013; 19:10101-6. [DOI: 10.1002/chem.201301760] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Indexed: 11/08/2022]
|
12
|
Albers A, Demeshko S, Pröpper K, Dechert S, Bill E, Meyer F. A Super-Reduced Diferrous [2Fe–2S] Cluster. J Am Chem Soc 2013; 135:1704-7. [DOI: 10.1021/ja311563y] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
13
|
Albers A, Demeshko S, Dechert S, Bill E, Bothe E, Meyer F. Die vollständige Charakterisierung eines reduzierten biomimetischen [2 Fe-2 S]-Clusters. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201100727] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
14
|
Albers A, Demeshko S, Dechert S, Bill E, Bothe E, Meyer F. The Complete Characterization of a Reduced Biomimetic [2 Fe-2 S] Cluster. Angew Chem Int Ed Engl 2011; 50:9191-4. [DOI: 10.1002/anie.201100727] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 05/24/2011] [Indexed: 11/08/2022]
|
15
|
Zhang Y, Angelin M, Larsson R, Albers A, Simons A, Ramström O. Tandem driven dynamic self-inhibition of acetylcholinesterase. Chem Commun (Camb) 2010; 46:8457-9. [DOI: 10.1039/c0cc02479a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
16
|
Albers A, Leon-Rovira N, Aguayo H, Maier T. Development of an engine crankshaft in a framework of computer-aided innovation. COMPUT IND 2009. [DOI: 10.1016/j.compind.2009.05.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
17
|
Ballmann J, Albers A, Demeshko S, Dechert S, Bill E, Bothe E, Ryde U, Meyer F. A synthetic analogue of Rieske-type [2Fe-2S] clusters. Angew Chem Int Ed Engl 2008; 47:9537-41. [PMID: 18972470 DOI: 10.1002/anie.200803418] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
18
|
Ballmann J, Albers A, Demeshko S, Dechert S, Bill E, Bothe E, Ryde U, Meyer F. Ein synthetisches Analogon für [2Fe-2S]-Cluster des Rieske-Typs. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200803418] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
19
|
Ballmann J, Albers A, Demeshko S, Dechert S, Bill E, Bothe E, Ryde U, Meyer F. Innentitelbild: Ein synthetisches Analogon für [2Fe-2S]-Cluster des Rieske-Typs (Angew. Chem. 49/2008). Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200890301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
20
|
Ballmann J, Albers A, Demeshko S, Dechert S, Bill E, Bothe E, Ryde U, Meyer F. Inside Cover: A Synthetic Analogue of Rieske-Type [2Fe-2S] Clusters (Angew. Chem. Int. Ed. 49/2008). Angew Chem Int Ed Engl 2008. [DOI: 10.1002/anie.200890252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
21
|
Albers A. Der Walzengranulator, eine neuartige Kompaktier- und Granuliermaschine. CHEM-ING-TECH 2006. [DOI: 10.1002/cite.200600102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
22
|
Schaefer C, Kim GG, Albers A, Hoermann K, Myers EN, Whiteside TL. Characteristics of CD4+CD25+ regulatory T cells in the peripheral circulation of patients with head and neck cancer. Br J Cancer 2005; 92:913-20. [PMID: 15714205 PMCID: PMC2361917 DOI: 10.1038/sj.bjc.6602407] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Patients with squamous cell carcinoma of the head and neck (SCCHN) have depressed antitumour immunity. The presence of CD4+CD25+ (Treg) cells in these patients might be, in part, responsible for downregulation of antitumour immune responses. To evaluate the frequency and characteristics of Treg in the peripheral circulation of patients with SCCHN, we used multicolour flow cytometry. Expression of CCR7, CD62L, ζ chain and Annexin V binding to Treg and non-Treg CD4+ lymphocyte populations were evaluated. Treg were confirmed to be Foxp3+ and GITR+. The Treg frequency was significantly elevated in patients with active disease and those with no evidence of disease (NED) following curative therapies. Both Treg and non-Treg CD4+ T cells in patients were significantly enriched in CCR7− and CD62L− cell subsets. Although Treg in patients contained a higher proportion of double negative (CCR7−CD62L−) cells, the majority of Tregs were CCR7−CD62L+. The proportion of Annexin V+CD4+ T cells was higher in patients (P<0.00005) than normal controls (NC), and Treg were significantly more sensitive to apoptosis than non-Treg in patients and NC. Expression of ζ was reduced in all subsets of CD4+ T cells obtained from patients vs NC. The data suggest that Treg in patients with SCCHN largely contain T cells with the ‘effector’ phenotype, which bind Annexin V and have low ζ expression, consistent with their activation state and a rapid turnover in the peripheral circulation.
Collapse
|
23
|
Kausch I, Jiang H, Brocks C, Albers A, Krüger S, Sczakiel G, Jocham D. [Ki-67 antisense therapy in murine renal cell carcinoma models]. Aktuelle Urol 2005; 36:142-8. [PMID: 15902575 DOI: 10.1055/s-2004-830205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE The Ki-67 antigen is only expressed in proliferating cells. Previously, it was shown that Ki-67 derived antisense oligonucleotides (asONs) specifically inhibit the proliferation of tumor cells and tumour growth in vitro and in subcutaneous bladder and prostate tumor models. We intended to evaluate the effects of this therapeutic concept in two renal cell carcinoma (RCC) models. MATERIAL AND METHODS Human RCC cells (SK-RC 35) were initially transfected with FITC-labeled ONs and diffferent cationic lipids to analyze the transfection efficacy by flow cytometry (FACS). The potency of 14 different ONs sequences was compared by quantitative RT-PCR in vitro. For in vivo testing, ONs were administered to immunocompetent Balb/c mice bearing orthotopic RENCA tumors as well as to SCID mice bearing subcutaneous RCC SK-RC 35 xenografts. Tumor sizes and final tumor weights were documented. Additionally, several immunohistochemical staining procedures were performed. RESULTS FACS analysis showed highly effective transfection conditions in vitro. Systemic administration of asONs significantly decreased the tumour growth in the RENCA model (p < 0.05) and in the SCID mouse model (p = 0.009). Immunohistochemical staining of tumor specimens revealed a marked down-regulation of target protein and a slight increase in apoptotic cells after antisense treatment while the microvessel count was not significantly altered. CONCLUSION These results demonstrate that the Ki-67 antigen represents a suitable antiproliferative target and that asONs directed against this target are potent drugs that induce a significant inhibition of renal tumor growth in different mouse models.
Collapse
|
24
|
Schäfer C, Albers A, Kim GG, Myers EN, Hoermann K, Whiteside T. CD4+CD25+ Regulatorische T Zellen in der peripheren Zirkulation von Kopf-Hals-Karzinom Patienten. Laryngorhinootologie 2004. [DOI: 10.1055/s-2004-823524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
25
|
Kolbow K, Mayer A, Albers A, Wollenberg B. Immunantwort gegen IL-2-transfizierte Plattenepithelkarziome. Laryngorhinootologie 2004. [DOI: 10.1055/s-2004-823508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|