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1.
Dr. Arianna Pina Malika Kadri Dr. Daniela Arosio Dr. Alberto Dal Corso Dr. Jean-Luc Coll Prof. Dr. Cesare Gennari Dr. Didier Boturyn 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(33):7492-7496
The use of multimeric ligands is considered as a promising strategy to improve tumor targeting for diagnosis and therapy. Herein, tetrameric RGD (Arg-Gly-Asp) peptidomimetics were designed to target αvβ3 integrin-expressing tumor cells. These compounds were prepared by an oxime chemoselective assembly of cyclo(DKP-RGD) ligands and a cyclodecapeptide scaffold, which allows a tetrameric presentation. The resulting tetrameric RGD peptidomimetics were shown to improve αvβ3 integrin binding compared with the monomeric form. Interestingly, these compounds were also able to enhance tumor cell endocytosis in the same way as tetrameric RGD peptides. Altogether, the results show the potential of the tetrameric cyclo(DKP-RGD) ligands for in vivo imaging and drug delivery. 相似文献
2.
Dr. Adina Borbély Dr. Fabien Thoreau Dr. Eduard Figueras Malika Kadri Dr. Jean-Luc Coll Dr. Didier Boturyn Prof. Dr. Norbert Sewald 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(12):2602-2605
The effective delivery of cytotoxic agents to tumor cells is a key challenge in anticancer therapy. Multivalent integrinspecific ligands are considered a promising tool to increase the binding affinity, selectivity, and internalization efficiency of small-molecule drug conjugates. Herein, we report the synthesis and biological evaluation of a multimeric conjugate containing the high-affinity integrin αvβ3 binding ligand RAFT-c(RGDfK)4, a lysosomally cleavable Val-Cit linker, and cryptophycin-55 glycinate, a potent inhibitor of tubulin polymerization. In vitro cytotoxicity assays verified that the multimeric RGD-cryptophycin conjugate displays improved potency compared to the monomeric analogue in integrin αvβ3 overexpressing tumor cell lines, while significantly reduced activity was observed in the integrin-negative cell line. 相似文献
3.
André Raposo Moreira Dias Arianna Pina Amelia Dean Dr. Hans-Georg Lerchen Dr. Michele Caruso Dr. Fabio Gasparri Dr. Ivan Fraietta Dr. Sonia Troiani Dr. Daniela Arosio Prof. Dr. Laura Belvisi Dr. Luca Pignataro Dr. Alberto Dal Corso Prof. Dr. Cesare Gennari 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(7):1696-1700
This work takes advantage of one of the hallmarks of cancer, that is, the presence of tumor infiltrating cells of the immune system and leukocyte-secreted enzymes, to promote the activation of an anticancer drug at the tumor site. The peptidomimetic integrin ligand cyclo(DKP-RGD) was found to accumulate on the surface of αvβ3 integrin-expressing human renal cell carcinoma 786-O cells. The ligand was conjugated to the anticancer drug paclitaxel through a Asn-Pro-Val (NPV) tripeptide linker, which is a substrate of neutrophil-secreted elastase. In vitro linker cleavage assays and cell antiproliferative experiments demonstrate the efficacy of this tumor-targeting conjugate, opening the way to potential therapeutic applications. 相似文献
4.
Two new cyclic RGD peptides were prepared using a click chemistry approach. The linear RGDfV peptide was synthesized by solid-phase peptide synthesis using a 9-fluorenylmetoxicarbonyl (Fmoc) strategy and a 2-chlorotrityl chloride resin. After coupling 5-hexynoic acid the peptide was cleaved from the resin and linked to propargylamine. The bis-alkynyl RGDfV peptide was then reacted with two different bis-azides by treatment with copper iodide and triethylamine. These two cyclic RGD peptides were characterized by NMR and HRMS. In order to evaluate the interaction of these new compounds with integrin αvβ3 docking experiments were carried out and the results compared with those obtained with cyclo(RGDf[N–Me]V) (Cilengitide). The two new cyclic RGD peptides showed a higher affinity to the αvβ3 integrin when compared with Cilengitide thus representing two new potential integrin αvβ3 antagonists. 相似文献
5.
Dr. Michele Anselmi Dr. Adina Borbély Dr. Eduard Figueras Carmela Michalek Dr. Isabell Kemker Prof. Dr. Luca Gentilucci Prof. Dr. Norbert Sewald 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(3):1015-1022
Most anticancer agents are hydrophobic and can easily penetrate the tumor cell membrane by passive diffusion. This may impede the development of highly effective and tumor-selective treatment options. A hydrophilic β-glucuronidase-cleavable linker was used to connect the highly potent antimitotic agent cryptophycin-55 glycinate with the αvβ3 integrin ligand c(RGDfK). Incorporation of the self-immolative linker containing glucuronic acid results in lower cytotoxicity than that of the free payload, suggesting that hydrophilic sugar linkers can preclude passive cellular uptake. In vitro drug-release studies and cytotoxicity assays demonstrated the potential of this small molecule–drug conjugate, providing guidance for the development of therapeutics containing hydrophobic anticancer drugs. 相似文献
6.
Cyclic isoDGR and RGD Peptidomimetics Containing Bifunctional Diketopiperazine Scaffolds are Integrin Antagonists
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Silvia Panzeri Simone Zanella Dr. Daniela Arosio Leila Vahdati Alberto Dal Corso Dr. Luca Pignataro Dr. Mayra Paolillo Prof. Dr. Sergio Schinelli Prof. Dr. Laura Belvisi Prof. Dr. Cesare Gennari Prof. Dr. Umberto Piarulli 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(16):6265-6271
The cyclo[DKP‐isoDGR] peptidomimetics 2 – 5 , containing bifunctional diketopiperazine (DKP) scaffolds that differ in the configuration of the two DKP stereocenters and in the substitution at the DKP nitrogen atoms, were prepared and examined in vitro in competitive binding assays with purified αvβ3 and αvβ5 integrin receptors. IC50 values ranged from low nanomolar (ligand 3 ) to submicromolar with αvβ3 integrin. The biological activities of ligands cyclo[DKP3‐RGD] 1 and cyclo[DKP3‐isoDGR] 3 , bearing the same bifunctional DKP scaffold and showing similar αVβ3 integrin binding values, were compared in terms of their cellular effects in human U373 glioblastoma cells. Compounds 1 and 3 displayed overlapping inhibitory effects on the FAK/Akt integrin activated transduction pathway and on integrin‐mediated cell infiltration processes, and qualify therefore, despite the different RGD and isoDGR sequences, as integrin antagonists. Both compounds induced apoptosis in glioma cells after 72 hour treatment. 相似文献
7.
Synthesis and In Vitro Photodynamic Activities of an Integrin‐Targeting cRGD‐Conjugated Zinc(II) Phthalocyanine
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A 1,4‐disubstituted zinc(II) phthalocyanine conjugated with a cyclic Arg‐Gly‐Asp‐D ‐Phe‐Lys (cRGDfK) moiety through a triazole linker was prepared and characterized by UV/Vis spectroscopy and high‐resolution ESI‐MS. The conjugate showed a relatively weak fluorescence emission in N,N‐dimethylformamide (ΦF=0.08), but it was a very efficient singlet oxygen generator (ΦΔ=0.80) as a result of the di‐α‐substituted structure. Owing to the presence of the cyclic peptide sequence cRGDfK, which is a well‐known αvβ3‐integrin antagonist, this conjugate exhibited significantly higher cellular uptake toward the αvβ3+ U87‐MG cells compared with the αvβ3? MCF‐7 cells, as determined by flow cytometry and fluorescence microscopy. The photocytotoxicity of this compound against these two cell lines, however, was comparable owing to the similar efficiency of intracellular reactive oxygen species generation. Confocal microscopic studies also revealed that this conjugate localized preferentially in the lysosomes, but not in the nucleus, endoplasmic reticulum, and mitochondria of the U87‐MG cells. 相似文献
8.
Adina Borbély Dr. Eduard Figueras Ana Martins Dr. Lizeth Bodero Dr. André Raposo Moreira Dias Dr. Paula López Rivas Dr. Arianna Pina Dr. Daniela Arosio Dr. Paola Gallinari Dr. Marcel Frese Dr. Christian Steinkühler Prof. Dr. Cesare Gennari Prof. Dr. Umberto Piarulli Prof. Dr. Norbert Sewald 《ChemistryOpen》2019,8(6):737-742
RGD-cryptophycin and isoDGR-cryptophycin conjugates were synthetized by combining peptidomimetic integrin ligands and cryptophycin, a highly potent tubulin-binding antimitotic agent across lysosomally cleavable Val-Ala or uncleavable linkers. The conjugates were able to effectively inhibit binding of biotinylated vitronectin to integrin αvβ3, showing a binding affinity in the same range as that of the free ligands. The antiproliferative activity of the novel conjugates was evaluated on human melanoma cells M21 and M21-L with different expression levels of integrin αvβ3, showing nanomolar potency of all four compounds against both cell lines. Conjugates containing uncleavable linker show reduced activity compared to the corresponding cleavable conjugates, indicating efficient intracellular drug release in the case of cryptophycin-based SMDCs. However, no significant correlation between the in vitro biological activity of the conjugates and the integrin αvβ3 expression level was observed, which is presumably due to a non-integrin-mediated uptake. This reveals the complexity of effective and selective αvβ3 integrin-mediated drug delivery. 相似文献
9.
Synthesis and Biological Evaluation of RGD Peptidomimetic–Paclitaxel Conjugates Bearing Lysosomally Cleavable Linkers
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Alberto Dal Corso Dr. Michele Caruso Dr. Laura Belvisi Dr. Daniela Arosio Prof. Dr. Umberto Piarulli Dr. Clara Albanese Dr. Fabio Gasparri Dr. Aurelio Marsiglio Dr. Francesco Sola Dr. Sonia Troiani Dr. Barbara Valsasina Dr. Luca Pignataro Dr. Daniele Donati Prof. Dr. Cesare Gennari 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(18):6921-6929
Two small‐molecule–drug conjugates (SMDCs, 6 and 7 ) featuring lysosomally cleavable linkers (namely the Val–Ala and Phe–Lys peptide sequences) were synthesized by conjugation of the αvβ3‐integrin ligand cyclo[DKP–RGD]‐CH2NH2 ( 2 ) to the anticancer drug paclitaxel (PTX). A third cyclo[DKP–RGD]–PTX conjugate with a nonpeptide “uncleavable” linker ( 8 ) was also synthesized to be tested as a negative control. These three SMDCs were able to inhibit biotinylated vitronectin binding to the purified αVβ3‐integrin receptor at nanomolar concentrations and showed good stability at pH 7.4 and pH 5.5. Cleavage of the two peptide linkers was observed in the presence of lysosomal enzymes, whereas conjugate 8 , which possesses a nonpeptide “uncleavable” linker, remained intact under these conditions. The antiproliferative activities of the conjugates were evaluated against two isogenic cell lines expressing the integrin receptor at different levels: the acute lymphoblastic leukemia cell line CCRF‐CEM (αVβ3?) and its subclone CCRF‐CEM αVβ3 (αVβ3+). Fairly effective integrin targeting was displayed by the cyclo[DKP–RGD]–Val–Ala–PTX conjugate ( 6 ), which was found to differentially inhibit proliferation in antigen‐positive CCRF‐CEM αVβ3 versus antigen‐negative isogenic CCRF‐CEM cells. The total lack of activity displayed by the “uncleavable” cyclo[DKP–RGD]–PTX conjugate ( 8 ) clearly demonstrates the importance of the peptide linker for achieving the selective release of the cytotoxic payload. 相似文献
10.
Yufei Ma Sheng Liang Hua Wu Hui Wang 《Journal of Radioanalytical and Nuclear Chemistry》2014,299(3):1865-1870
The successes of noninvasive methods to visualize and quantify integrin αvβ3 expression in vivo have paved the way for radiolabeling anti-integrin therapy in clinic. Arginine-glycine-aspartice (RGD) peptide and related derivatives labeled with radionuclides for radio-therapy, which specifically targeting integrin αvβ3-positive tumors, could be used to treat these tumors. We have labeled c(RGDyK)-His, a RGD derivative, with 188Re and the radio-therapy efficiency has been evaluated in model nude mice. c(RGDyK)-His was labeled with 188Re by chelating with [188Re(CO)3(H2O)3]+ under a slightly basic condition. The in vitro specific binding affinity to U87 MG cell lines and the biodistribution of 188Re-c(RGDyK)-His in the animal tumor models was measured. The inhibitory effects of 188Re-c(RGDyK)-His were observed more than 1 month, and evaluated by microPET/CT imaging with 18F-FDG. Results of in vivo, cell uptake demonstrated 188Re-c(RGDyK)-His had a high specific binding affinity to receptor integrin αvβ3. In biodistribution experiment, 188Re-c(RGDyK)-His was accumulated in the tumor and cleared fast from the normal tissues. In radiotherapy study, tumor growth inhibition was significantly higher in the treatment groups than in the control groups. These studies showed that 188Re-c(RGDyK)-His could be effectively used for integrin αvβ3 targeting therapy. This may offer a potential therapeutic strategy for the treatment of integrin-positive tumors in clinic. 相似文献
11.
Jakub Šimeček Prof. Dr. Petr Hermann Dr. Jana Havlíčková Dr. Eberhardt Herdtweck Tobias G. Kapp Nils Engelbogen Prof. Dr. Horst Kessler Prof. Dr. Hans‐Jürgen Wester Dr. Johannes Notni 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(24):7748-7757
The cyclen‐based tetraphosphinate chelator 1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetrakis[methylene(2‐carboxyethyl)phosphinic acid] (DOTPI) comprises four additional carboxylic acid moieties for bioconjugation. The thermodynamic stability constants (logKML) of metal complexes, as determined by potentiometry, were 23.11 for CuII, 20.0 for LuIII, 19.6 for YIII, and 21.0 for GdIII. DOTPI was functionalized with four cyclo(Arg‐Gly‐Asp‐D ‐Phe‐Lys) (RGD) peptides through polyethylene glycol (PEG4) linkers. The resulting tetrameric conjugate DOTPI(RGD)4 was radiolabeled with 177Lu and 64Cu and showed improved labeling efficiency compared with 1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetic acid (DOTA). The labeled compounds were fully stable in transchelation challenges against trisodium diethylenetriaminepentaacetate (DTPA) and disodium ethylenediaminetetraacetic acid (ETDA), in phosphate buffered saline (PBS), and human plasma. Integrin αvβ3 affinities of the non‐radioactive LuIII and CuII complexes of DOTPI(RGD)4 were 18 times higher (both IC50 about 70 picomolar) than that of the c(RGDfK) peptide (IC50=1.3 nanomolar). Facile access to tetrameric conjugates and the possibility of radiolabeling with therapeutic and diagnostic radionuclides render DOTPI suitable for application in peptide receptor radionuclide imaging (PRRI) and therapy (PRRT). 相似文献
12.
A Precise Chemical Strategy To Alter the Receptor Specificity of the Adeno‐Associated Virus
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Rachel E. Kelemen Dr. Raja Mukherjee Xiaofu Cao Sarah B. Erickson Yunan Zheng Prof. Abhishek Chatterjee 《Angewandte Chemie (International ed. in English)》2016,55(36):10645-10649
The ability to target the adeno‐associated virus (AAV) to specific types of cells, by altering the cell‐surface receptor it binds, is desirable to generate safe and efficient therapeutic vectors. Chemical attachment of receptor‐targeting agents onto the AAV capsid holds potential to alter its tropism, but is limited by the lack of site specificity of available conjugation strategies. The development of an AAV production platform is reported that enables incorporation of unnatural amino acids (UAAs) into specific sites on the virus capsid. Incorporation of an azido‐UAA enabled site‐specific attachment of a cyclic‐RGD peptide onto the capsid, retargeting the virus to the αvβ3 integrin receptors, which are overexpressed in tumor vasculature. Retargeting ability was site‐dependent, underscoring the importance of achieving site‐selective capsid modification. This work provides a general chemical approach to introduce various receptor binding agents onto the AAV capsid with site selectivity to generate optimized vectors with engineered infectivity. 相似文献
13.
There is considerable interest in the development of novel and more efficient delivery systems for improving the efficacy of photodynamic therapy (PDT). The authors in this highlighted issue describe the synthesis and the photobiological characterizations of two photosensitizer (PS) conjugates based on β‐carboline derivatives covalently conjugated to folic acid (FA) coupled to bovine serum albumin (BSA) as a carrier system specifically targeting cancer cells overexpressing FA receptor alpha (FRα). Accordingly, only the FA–BSA–β‐carboline conjugates are internalized specifically in FRα‐positive cells and are proved to be phototoxic. On the other hand, albumin–β‐carboline conjugates without FA or β‐carboline derivatives alone are not internalized and nontoxic. This conjugate is among the first to produce a conjugate composed of a PS and FA molecules that are directly conjugated to BSA. In addition, the in vitro studies are the first evidence that directly conjugated FA‐BSA can be used as carriers to selectively enhance cytotoxicity by PDT relative to unmodified PS or nontargeted BSA‐PS. This strategy is a positive step forward for the covalent design and construction of a photodynamic nanomedicine for FR‐positive tumors. 相似文献
14.
Dr. Elmira Ghabraie Dr. Isabell Kemker Dr. Nicolo Tonali Dr. Mohamed Ismail Dr. Veronica I. Dodero Prof. Dr. Norbert Sewald 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(52):12036-12042
Cyclic RGD peptides are well-known ligands of integrins. The integrins αVβ3 and α5β1 are involved in angiogenesis, and integrin αVβ3 is abundantly present on cancer cells, thus representing a therapeutic target. Hence, synthetic and biophysical studies continuously are being directed towards the understanding of ligand-integrin interaction. In this context, the development of versatile synthetic strategies to obtain fluorescent building blocks that can add molecular diversity and modular spectral characteristics while not compromising binding affinity or selectivity is a relevant task. An on-resin intramolecular Suzuki–Miyaura cross-coupling (SMC) between l - or d -7-bromotryptophan (7BrTrp) and a phenothiazine (Ptz) boronic acid affords fluorescent cyclic RGD pseudopeptides, c(RGD(W/w)Ptz). Ring closure by SMC establishes a phenothiazine–indole moiety with axial chirality. An array of eight novel compounds has been synthesized, among them one fluorescent compound with good affinity to integrin αVβ3. The fluorescence properties of the analogues can be efficiently tuned depending on the substituents in Ptz moiety even for fluorescence emission in the visible (red) spectral range. 相似文献
15.
A Combined NMR and Computational Approach to Determine the RGDechi‐hCit‐αvβ3 Integrin Recognition Mode in Isolated Cell Membranes
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Dr. Biancamaria Farina Dr. Ivan de Paola Dr. Luigi Russo Dr. Domenica Capasso Dr. Annamaria Liguoro Dr. Annarita Del Gatto Dr. Michele Saviano Prof. Paolo V. Pedone Dr. Sonia Di Gaetano Dr. Gaetano Malgieri Dr. Laura Zaccaro Prof. Roberto Fattorusso 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(2):681-693
The critical role of integrins in tumor progression and metastasis has stimulated intense efforts to identify pharmacological agents that can modulate integrin function. In recent years, αvβ3 and αvβ5 integrin antagonists were demonstrated to be effective in blocking tumor progression. RGDechi‐hCit, a chimeric peptide containing a cyclic RGD motif linked to an echistatin C‐terminal fragment, is able to recognize selectively αvβ3 integrin both in vitro and in vivo. High‐resolution molecular details of the selective αvβ3 recognition of the peptide are certainly required, nonetheless RGDechi‐hCit internalization limited the use of classical in cell NMR experiments. To overcome such limitations, we used WM266 isolated cellular membranes to accomplish a detailed NMR interaction study that, combined with a computational analysis, provides significant structural insights into αvβ3 molecular recognition by RGDechi‐hCit. Remarkably, on the basis of the identified molecular determinants, we design a RGDechi‐hCit mutant that is selective for αvβ5 integrin. 相似文献
16.
Marcus Koppitz Martin Huenges Rainer Gratias Horst Kessler Simon L. Goodman Alfred Jonczyk 《Helvetica chimica acta》1997,80(4):1280-1300
The αv/β3 integrin is implicated in human tumor metastasis and angiogenesis. It has been shown that structures of the sequence cyclo(-Arg1-Gly2-Asp3-D -Phe4-Xaa5-) ( I ) and cyclo(-Arg1-Gly2-Asp3-Phe4-D -Xaa5-) ( II ) bind with high affinity and the latter with high selectivity to this receptor. The residues Xaa and D -Xaa accept a broad variety of amino acids. Here, we report on the synthesis, activities, and conformational analysis of cyclic Arg-Gly-Asp (RGD) peptides containing liophilic amino acids Xaa or D -Xaa in position 5. For I , these were (2S)-2-aminohexadecanoic acid (Ahd) and N′-hexadecylglycine (Hd-Gly) and in II , D -Ahd and Hd-Gly, and, for control purposes, Ahd were incorporated (Fig. 1). The enantiomerically pure a-amino acids were obtained by non-enantioselective synthesis and subsequent enzymatic separation of isomers using acylase I (Scheme). Hd-Gly was prepared in a modified procedure according to Stewart from ethyl bromoacetate and hexadecylamine (Scheme). The synthesis and physicochemical properties of the corresponding (9H-fluoren-9-ylmethoxy)carbonyl (Fmoc) derivatives, compatible with solid-phase peptide synthesis, are described. Structure elucidation by NMR reveals that the lipid modification has no significant impact on the template structures when incorporated into them. For peptides I with Xaa = Ahd or Hd-Gly ( 1 or 2 ), a βII′/γ-turn-like arrangement with D -Phe in i+1 position of the β-turn is found. Peptides II with D -Xaa = D -Ahd or Hd-Gly ( 3 or 4 ) exhibit a βII′/γ-turn conformation with Gly in i+1 position of the β-turn, whereas II with Ahd instead of D -Xaa, i.e., lacking a D -amino acid in position 4 or 5 ( 5 ). adopts no defined conformation. However, in assays of receptor specificity employing human αvv/β3 integrin, the compounds exhibit IC50 values ranging from nanomolar to less than millimolar. These results indicate that although the arrangement of the pharmacophoric groups is preserved in the target compounds, the biological activity is highly dependent on spatial requirements of the lipid anchor in the receptor binding pocket. Obviously, only certain positions do not affect the binding. 相似文献
17.
《化学:亚洲杂志》2017,12(21):2813-2818
αvβ3 Integrin is upregulated on many cancer cells. We designed a dual functional cyclic peptide gatekeeper with a capability of stimuli‐responsive conformational transformation which could serve as a selective cell‐targeting on–off gatekeeper for mesoporous nanocarriers. The advantage of employing the motif of stimuli‐induced conformational transformation of cyclic peptides is that they could be utilized not only as an on–off gatekeeper for the triggered release of cargo drugs but also as a targeting ligand of the carriers to desired cells with their respective binding receptors. The peptide gatekeepers on the surface of nanocarriers exhibited on–off gatekeeping via conformational transformation triggered by intracellular glutathione levels of the cancer cells. The cyclic RGD sequence of the peptide gatekeepers enhanced the intracellular uptake into tumor cells (A549) and the therapeutic efficacy of the nanocarrier. 相似文献
18.
Yoshitaka Takezawa Noriaki Taketani Seikichi Tanno Shuichi Ohara 《Journal of Polymer Science.Polymer Physics》1992,30(8):879-885
We have studied simple empirical equations to estimate light absorption loss αv due to harmonics of molecular vibrations of transparent amorphous polymers used in plastic optical fibers (POFs). In the visible region, absorption involves two losses. One is αv, and the other is the electronic transition absorption loss, αe. Of the two, αv is considerably larger than αe in the wavelength region used for optical communication with POFs. We have clarified relationships between chemical structure of repeat units of polymers and αv. We find that αv is proportional to the concentration of specific chemical bonds (C? H, N? H, and Obond;H bonds) in the polymer solid, and we propose empirical equations to estimate αv from the polymer density and the chemical structure of the repeat unit. These equations are used to estimate αv of several polymers [i.e., poly(methyl methacrylate), polystyrene, and polycarbonate]. The estimated values are nearly equal to the experimental or reference values. Furthermore, to minimize the attenuation in the POF, we conclude that the POF core polymer should have no N? H, O? H, or aliphatic C? H bonds in its repeat unit. 相似文献
19.
Jiang Liu Xin Liu Fangfang Zhang Jiaojiao Qu Prof. Dr. Hongyan Sun Prof. Dr. Qing Zhu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(68):16122-16128
Fluorescent stapled peptides are important chemical tools for detecting intracellular distribution, protein–protein interactions, and localization of target proteins. These peptides are usually labeled with bulky sized fluorophores through reactive functional groups, which may alter the physical properties and biological activities of peptides. Herein, a unique strategy is developed for synthesizing new stapled peptides with built-in fluorescence. The stapled peptides were prepared through Rh-catalyzed C(sp2)−H olefination in tryptophan (Trp) residues by using pyridine/pyrimidine as the directing groups under mild conditions. This method displays good regioselectivity and high efficiency. Furthermore, as a proof of concept for its biological applications, stapled peptides without additional fluorophore 9 a and 9 b were constructed for a cell imaging study. These peptides displayed strong binding affinity toward integrin αvβ3 in A549 cells by cell imaging experiments. Notably they demonstrated even better anticancer activity than commercial antagonist cyclic (RGDfK). The method will provide robust tools for the peptide macrocyclization field. 相似文献
20.
《中国化学快报》2020,31(12):3107-3112
Angiogenesis occurs during the process of tumor growth, invasion and metastasis, and is essential for the survival of solid tumors. As an integrin significantly overexpressed in human tumor vascular endothelial cells, αvβ3 is a suitable targeting site for anti-angiogenesis of tumor. We designed and prepared a self-assembling peptide (SAP) with the ability to targeting αvβ3 and self-assembly. SAP formed nanoparticles in solution and transformed into nanofibrous network once specifically binding to integrin αvβ3 on the surface of human umbilical vein endothelial cells (HUVECs). The SAP network stably anchored on HUVECs over 24 h, which consequently resulted in high-efficient inhibition of vascularization. In vitro anti-angiogenesis experiment displayed that the inhibition rate of tube-formation reached 94.9%. In vivo anti-angiogenesis array based on chick chorioallantoic membrane (CAM) model exhibited that the SAP had an inhibition rate up to 63.1%. These results indicated the outstanding anti-angiogenic ability of SAP, potentially for tumor therapy. 相似文献