• MeSH
• peptidy farmakologie   MeSH
• techniky in vitro MeSH
• virové nemoci prevence a kontrola   MeSH
• virus slintavky a kulhavky MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH

A novel and facile in vitro cell sensing system has been developed with one-step electropolymerization of the conducting polypyrrole(PPy) polymer using RGD peptide as the sole dopant on an indium tin oxide (ITO) surface. The resulted RGD peptide-doped polypyrrole (PPy/RGD) composite film had a robust surface, in which PPy provided a biocompatible matrix for cell growth and a conducting interface for electrical detection, while the RGD peptide entrapped in the PPy matrix conferred the desired biomimetic properties. Using the human lung cancer cell A549 as a model, this system can be used to monitor cell behaviors of proliferation and cytotoxicity.

• Klíčová slova
• RGD peptidy, elektropolymerizace, polypyrrole,
• MeSH
• antitumorózní látky toxicita   MeSH
• biomimetické materiály MeSH
• biosenzitivní techniky * MeSH
• oligopeptidy MeSH
• polymery MeSH
• proliferace buněk MeSH
• pyrroly * MeSH
• skenovací elektrochemická mikroskopie MeSH
• Publikační typ
• práce podpořená grantem MeSH

Cyclic pentapeptides containing the amino acid sequence arginine-glycine-aspartic (RGD) have been widely applied to target αvβ3 integrin, which is upregulated in various tumors during tumor-induced angiogenesis. Multimeric cyclic RGD peptides have been reported to be advantageous over monomeric counterparts for angiogenesis imaging. Here, we prepared mono-, di-, and trimeric cyclic arginine-glycine-aspartic-D-phenylalanine-lysine (c (RGDfK)) derivatives by conjugation with the natural chelator fusarinine C (FSC) using click chemistry based on copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC). The αvβ3 binding properties of 68Ga-labeled mono-, di-, and trimeric c(RGDfK) peptides were evaluated in vitro as well as in vivo and compared with the references monomeric [68Ga]GaNODAGA-c(RGDfK) and trimeric [68Ga]GaFSC(suc-c(RGDfK))3. All 68Ga-labeled c(RGDfK) peptides displayed hydrophilicity (logD = -2.96 to -3.80), low protein binding and were stable in phosphate buffered-saline (PBS) and serum up to 2 h. In vitro internalization assays with human melanoma M21 (αvβ3-positive) and M21-L (αvβ3-negative) cell lines showed specific uptake of all derivatives and increased in the series: mono- < di- < trimeric peptide. The highest tumor uptake, tumor-to-background ratios, and image contrast were found for the dimeric [68Ga]GaMAFC(c(RGDfK)aza)2. In conclusion, we developed a novel strategy for direct, straight forward preparation of mono-, di-, and trimeric c(RGDfK) conjugates based on the FSC scaffold. Interestingly, the best αvβ3 imaging properties were found for the dimeric [68Ga]GaMAFC(c(RGDfK)aza)2.

• MeSH
• alkyny chemie   MeSH
• azidy chemie   MeSH
• cyklické peptidy chemie   farmakokinetika   MeSH
• izotopové značení MeSH
• měď chemie   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• PET/CT MeSH
• polymerizace MeSH
• radioizotopy galia chemie   MeSH
• siderofory chemie   MeSH
• syntetická chemie okamžité shody MeSH
• tkáňová distribuce MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

The surface of poly(L-lactide) (PLLA) films deposited on glass coverslips was modified with poly(DL-lactide) (PDLLA), or 1:4 mixtures of PDLLA and PDLLA-b-PEO block copolymers, in which either none, 5% or 20% of the copolymer molecules carried a synthetic extracellular matrix-derived ligand for integrin adhesion receptors, the GRGDSG oligopeptide, attached to the end of the PEO chain. The materials, perspective for vascular tissue engineering, were seeded with rat aortic smooth muscle cells (11,000 cells/cm(2)) and the adhesion, spreading, DNA synthesis and proliferation of these cells was followed on inert and bioactive surfaces. In 24-h-old cultures in serum-supplemented media, the number of cells adhering to the PDLLA-b-PEO copolymer was almost eight times lower than that on the control PDLLA surface. On the surfaces containing 5% and 20% GRGDSG-PEO-b-PDLLA copolymer, the number of cells increased 6- and 3-fold respectively, compared to the PDLLA-b-PEO copolymer alone. On PDLLA-b-PEO copolymer alone, the cells were typically round and non-spread, whereas on GRGDSG-modified surfaces the cell spreading areas approached those found on PDLLA, reaching values of 991 microm(2) and 611 microm(2) for 5% and 20% GRGDSG respectively, compared to 958 microm(2) for PDLLA. The cells on GRGDSG-grafted copolymers were able to form vinculin-containing focal adhesion plaques, to synthesize DNA and even proliferate in a serum-free medium, which indicates specific binding to the GRGDSG sequences through their adhesion receptors.

• MeSH
• biokompatibilní potahované materiály aplikace a dávkování   chemie   MeSH
• buněčná adheze účinky léků   MeSH
• buněčné kultury metody   MeSH
• financování organizované MeSH
• krysa rodu rattus MeSH
• kultivované buňky MeSH
• myocyty hladké svaloviny cytologie   fyziologie   účinky léků   MeSH
• oligopeptidy aplikace a dávkování   chemie   MeSH
• polyestery chemie   MeSH
• potkani Wistar MeSH
• povrchové vlastnosti MeSH
• proliferace buněk účinky léků   MeSH
• svaly hladké cévní cytologie   fyziologie   účinky léků   MeSH
• testování materiálů MeSH
• tkáňové inženýrství metody   MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH

The cellular adhesion receptor αvβ6-integrin is highly expressed in many cancers, e.g., pancreatic, lung, head-and-neck, cervical, bladder, and esophageal carcinoma. Multimerization of αvβ6-integrin-specific RGD peptides increases the target affinity and retention but affects biodistribution and pharmacokinetics. Amide formation of the terminal carboxylic acid moieties of the square-symmetrical bifunctional chelator DOTPI with 3-azidopropylamine yields derivatives with 4, 3, and 2 terminal azides and zero, 1, and 2 remaining carboxylic acids, respectively, whereby formation of the 2-cis-isomer is preferred according to NMR investigation of the Eu(III)-complexes. Cu(II)-catalyzed alkyne-azide cycloaddition (CuAAC) of the alkyne-functionalized αvβ6-integrin binding peptide cyclo[YRGDLAYp(NMe)K(pent-4-ynoic amide)] (Tyr2) yields the respective di-, tri-, and tetrameric conjugates for Lu-177-labeling. In mice bearing αvβ6-integrin-expressing xenografts of H2009 (human lung adenocarcinoma) cells, the Lu-177-labeled trimer's tumor-to-blood ratio of 112 exceeds that of the tetramer (10.4) and the dimer (54). Co-infusion of gelofusine (succinylated gelatin) reduces the renal uptake of the trimer by 89%, resulting in a 10-fold better tumor-to-kidney ratio, while no improvement of that ratio is observed with arginine/lysine, para-aminohippuric acid (PAH), and hydroxyethyl starch (HES) coinfusions. Since the Lu-177-labeled Tyr2-trimer outperforms the dimer and the tetramer, such trimers are considered the best lead structures for the ongoing development of αvβ6-integrin targeted anticancer theranostics.

• MeSH
• antigeny nádorové * metabolismus   MeSH
• chelátory * chemie   MeSH
• integriny * metabolismus   MeSH
• lidé MeSH
• lutecium * chemie   MeSH
• myši nahé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory farmakoterapie   MeSH
• oligopeptidy * chemie   farmakokinetika   MeSH
• radiofarmaka farmakokinetika   chemie   terapeutické užití   MeSH
• radionuklidy * chemie   MeSH
• syntetická chemie okamžité shody MeSH
• teranostická nanomedicína metody   MeSH
• tkáňová distribuce MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE: Multimeric arginine-glycine-aspartic acid (RGD) peptides have advantages for imaging integrin αvβ3 expression. Here, we compared the in vitro and in vivo behavior of three different Ga-68-labeled multimeric Fusarinine C-RGD (FSC-RGD) conjugates, whereby RGD was coupled directly, via a succinic acid or PEG linker (FSC(RGDfE)3, FSC(succ-RGD)3, FSC(Mal-RGD)3). The positron emission tomography/X-ray computed tomography (PET/CT) imaging properties were further compared using [(68)Ga]FSC(succ-RGD)3 with the monomeric [(68)Ga]NODAGA-RGD in a murine tumor model. PROCEDURE: FSC-RGD conjugates were labeled with Ga-68, and stability properties were studied. For in vitro characterization, the partition coefficient, integrin αvβ3 binding affinity, and cell uptake were determined. To characterize the in vivo properties, biodistribution studies and microPET/CT were carried out using mice bearing either human M21/M21-L melanoma or human U87MG glioblastoma tumor xenografts. RESULTS: All FSC-RGD conjugates were quantitatively labeled with Ga-68 within 10 min at RT. The [(68)Ga]FSC-RGD conjugates exhibited high stability and hydrophilic character, with only minor differences between the different conjugates. In vitro and in vivo studies showed enhanced integrin αvβ3 binding affinity, receptor-selective tumor uptake, and rapid renal excretion resulting in good imaging properties. CONCLUSIONS: The type of linker between FSC and RGD had no pronounced effect on targeting properties of [(68)Ga]FSC-RGD trimers. In particular, [(68)Ga]FSC(succ-RGD)3 exhibited improved properties compared to [(68)Ga]NODAGA-RGD, making it an alternative for imaging integrin αvβ3 expression.

• MeSH
• acetáty chemie   MeSH
• endocytóza MeSH
• heterocyklické sloučeniny monocyklické chemie   MeSH
• kyseliny hydroxamové chemie   MeSH
• lidé MeSH
• melanom diagnostické zobrazování   patologie   MeSH
• myši inbrední BALB C MeSH
• myši nahé MeSH
• nádorové buněčné linie MeSH
• oligopeptidy chemie   MeSH
• PET/CT * MeSH
• radiofarmaka chemie   MeSH
• radioizotopy galia MeSH
• tkáňová distribuce MeSH
• xenogenní modely - testy antitumorózní aktivity * MeSH
• železité sloučeniny chemie   MeSH
• zobrazování trojrozměrné MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

Hydrogel scaffolds which bridge the lesion, together with stem cell therapy represent a promising approach for spinal cord injury (SCI) repair. In this study, a hydroxyphenyl derivative of hyaluronic acid (HA-PH) was modified with the integrin-binding peptide arginine-glycine-aspartic acid (RGD), and enzymatically crosslinked to obtain a soft injectable hydrogel. Moreover, addition of fibrinogen was used to enhance proliferation of human Wharton's jelly-derived mesenchymal stem cells (hWJ-MSCs) on HA-PH-RGD hydrogel. The neuroregenerative potential of HA-PH-RGD hydrogel was evaluated in vivo in acute and subacute models of SCI. Both HA-PH-RGD hydrogel injection and implantation into the acute spinal cord hemisection cavity resulted in the same axonal and blood vessel density in the lesion area after 2 and 8 weeks. HA-PH-RGD hydrogel alone or combined with fibrinogen (HA-PH-RGD/F) and seeded with hWJ-MSCs was then injected into subacute SCI and evaluated after 8 weeks using behavioural, histological and gene expression analysis. A subacute injection of both HA-PH-RGD and HA-PH-RGD/F hydrogels similarly promoted axonal ingrowth into the lesion and this effect was further enhanced when the HA-PH-RGD/F was combined with hWJ-MSCs. On the other hand, no effect was found on locomotor recovery or the blood vessel ingrowth and density of glial scar around the lesion. In conclusion, we have developed and characterized injectable HA-PH-RGD based hydrogel, which represents a suitable material for further combinatorial therapies in neural tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1129-1140, 2018.

• MeSH
• hydrogely chemie   MeSH
• injekce * MeSH
• kyselina hyaluronová chemie   MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• mezenchymální kmenové buňky cytologie   účinky léků   MeSH
• oligopeptidy chemie   MeSH
• pohybová aktivita MeSH
• poranění míchy patologie   patofyziologie   MeSH
• potkani Wistar MeSH
• regenerace míchy * MeSH
• tkáňové podpůrné struktury chemie   MeSH
• Whartonův rosol cytologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Polymer layers capable of suppressing protein adsorption from biological media while presenting extracellular matrix-derived peptide motifs offer valuable new options for biomimetic surface engineering. Herein, we provide detailed insights into physicochemical changes induced in a nonfouling poly(ethylene oxide) (PEO) brush/polydopamine (PDA) system by incorporation of adhesion ligand (RGD) peptides. Brushes with high surface chain densities (σ ≥ 0.5 chains·nm-2) and pronounced hydrophilicity (water contact angles ≤ 10°) were prepared by end-tethering of heterobifunctional PEOs ( Mn ≈ 20 000 g·mol-1) to PDA-modified surfaces from a reactive melt. Using alkyne distal end group on the PEO chains, azidopentanoic-bearing peptides were coupled through a copper-catalyzed Huisgen azide-alkyne "click" cycloaddition reaction. The surface concentration of RGD was tuned from complete saturation of the PEO surface with peptides (1.7 × 105 fmol·cm-2) to values which may induce distinct differences in cell adhesion (<6.0 × 102 fmol·cm-2). Infrared reflection-absorption and X-ray photoelectron spectroscopies proved the PDA-PEO layers covalent structure and the immobilization of RGD peptides. The complete reconstruction of experimental electrohydrodynamics data utilizing mean-field theory predictions further verified the attained brush structure of the end-tethered PEO chains which provided hydrodynamic screening of the PDA anchor. Increasing the surface concentration of immobilized RGD peptides led to increased interfacial charging. Supported by simulations, this observation was attributed to the ionization of functional groups in the amino acid sequence and to the pH-dependent adsorption of water ions (OH- > H3O+) from the electrolyte. Despite the distinct differences observed in the electrokinetic analysis of the surfaces bearing different amounts of RGD, it was found that the peptide presence on PEO(20 000)-PDA layers does not have a significant effect on the nonfouling properties of the system. Notably, the presented PEO(20 000)-PDA layers bearing RGD peptides in the surface concentration range 5.9 to 1.7 × 105 fmol·cm-2 reduced the protein adsorption from fetal bovine serum to less than 30 ng·cm-2, that is, values comparable to the ones obtained for pristine PEO(20 000)-PDA layers.000)-PDA layers bearing RGD peptides in the surface concentration range 5.9 to 1.7 x 105 fmol.cm-2 reduced the protein adsorption from fetal bovine serum to less than 30 ng.cm-2, that is, values comparable to the ones obtained for pristine PEO(20 000)-PDA layers.

• MeSH
• adsorpce MeSH
• buněčná adheze MeSH
• fotoelektronová spektroskopie MeSH
• molekulární struktura MeSH
• peptidy * chemie   MeSH
• polyethylenglykoly * chemie   MeSH
• povrchové vlastnosti MeSH

The incorporation of the RGD peptide (arginine-glycine-aspartate) into biomaterials has been proposed to promote cell adhesion to the matrix, which can influence and control cell behaviour and function. While many studies have utilised RGD modified biomaterials for cell delivery, few have examined its effect under the condition of reduced oxygen and nutrients, as found at ischaemic injury sites. Here, we systematically examine the effect of RGD on hMSCs in hyaluronic acid (HA) hydrogel under standard and ischaemic culture conditions, to elucidate under what conditions RGD has beneficial effects over unmodified HA and its effectiveness in improving cell viability. Results demonstrate that under standard culture conditions, RGD significantly increased hMSC spreading and the release of vascular endothelial factor-1 (VEGF) and monocyte chemoattractant factor-1 (MCP-1), compared to unmodified HA hydrogel. As adhesion is known to influence cell survival, we hypothesised that cells in RGD hydrogels would exhibit increased cell viability under ischaemic culture conditions. However, results demonstrate that cell viability and protein release was comparable in both RGD modified and unmodified HA hydrogels. Confocal imaging revealed cellular morphology indicative of weak cell adhesion. Subsequent investigations found that RGD was could exert positive effects on encapsulated cells under ischaemic conditions but only if hMSCs were pre-cultured under standard conditions to allow strong adhesion to RGD before exposure. Together, these results provide novel insight into the value of RGD introduction and suggest that the adhesion of hMSCs to RGD prior to delivery could improve survival and function at ischaemic injury sites. STATEMENT OF SIGNIFICANCE: The development of a biomaterial scaffold capable of maintaining cell viability while promoting cell function is a major research goal in the field of cardiac tissue engineering. This study confirms the suitability of a modified HA hydrogel whereby stem cells in the modified hydrogel showed significantly greater cell spreading and protein secretion compared to cells in the unmodified HA hydrogel. A pre-culture period allowing strong adhesion of the cells to the modified hydrogel was shown to improve cell survival under conditions that mimic the myocardium post-MI. This finding may have a significant impact on the use and timelines of modifications to improve stem cell survival in harsh environments like the injured heart.

• MeSH
• buněčná adheze účinky léků   MeSH
• buněčné kultury MeSH
• hydrogely chemie   MeSH
• hypoxie buňky fyziologie   MeSH
• kyselina hyaluronová chemie   MeSH
• lidé MeSH
• mezenchymální kmenové buňky cytologie   fyziologie   MeSH
• oligopeptidy chemie   MeSH
• tkáňové inženýrství metody   MeSH
• tkáňové podpůrné struktury chemie   MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Drug delivery to central nervous pathologies is compromised by the blood-brain barrier (BBB). A clinically explored strategy to promote drug delivery across the BBB is sonopermeation, which relies on the combined use of ultrasound (US) and microbubbles (MB) to induce temporally and spatially controlled opening of the BBB. We developed an advanced in vitro BBB model to study the impact of sonopermeation on the delivery of the prototypic polymeric drug carrier pHPMA as a larger molecule and the small molecule antiviral drug ribavirin. This was done under standard and under inflammatory conditions, employing both untargeted and RGD peptide-coated MB. The BBB model is based on human cerebral capillary endothelial cells and human placental pericytes, which are co-cultivated in transwell inserts and which present with proper transendothelial electrical resistance (TEER). Sonopermeation induced a significant decrease in TEER values and facilitated the trans-BBB delivery of fluorescently labeled pHPMA (Atto488-pHPMA). To study drug delivery under inflamed endothelial conditions, which are typical for e.g. tumors, neurodegenerative diseases and CNS infections, tumor necrosis factor (TNF) was employed to induce inflammation in the BBB model. RGD-coated MB bound to and permeabilized the inflamed endothelium-pericyte co-culture model, and potently improved Atto488-pHPMA and ribavirin delivery. Taken together, our work combines in vitro BBB bioengineering with MB-mediated drug delivery enhancement, thereby providing a framework for future studies on optimization of US-mediated drug delivery to the brain.

• MeSH
• antivirové látky aplikace a dávkování   chemie   farmakologie   farmakokinetika   MeSH
• endoteliální buňky * účinky léků   metabolismus   MeSH
• hematoencefalická bariéra * metabolismus   MeSH
• kokultivační techniky * MeSH
• lidé MeSH
• mikrobubliny * MeSH
• oligopeptidy * chemie   aplikace a dávkování   farmakokinetika   MeSH
• pericyty * metabolismus   účinky léků   MeSH
• polymery chemie   aplikace a dávkování   MeSH
• ribavirin aplikace a dávkování   chemie   farmakokinetika   MeSH
• systémy cílené aplikace léků metody   MeSH
• ultrazvukové vlny MeSH
• zánět farmakoterapie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH