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Al Tabosh T, Liu H, Koça D, Al Tarrass M, Tu L, Giraud S, Delagrange L, Beaudoin M, Rivière S, Grobost V, Rondeau-Lutz M, Dupuis O, Ricard N, Tillet E, Machillot P, Salomon A, Picart C, Battail C, Dupuis-Girod S, Guignabert C, Desroches-Castan A, Bailly S. Impact of heterozygous ALK1 mutations on the transcriptomic response to BMP9 and BMP10 in endothelial cells from hereditary hemorrhagic telangiectasia and pulmonary arterial hypertension donors. Angiogenesis 2024; 27:211-227. [PMID: 38294582 PMCID: PMC11021321 DOI: 10.1007/s10456-023-09902-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 12/03/2023] [Indexed: 02/01/2024]
Abstract
Heterozygous activin receptor-like kinase 1 (ALK1) mutations are associated with two vascular diseases: hereditary hemorrhagic telangiectasia (HHT) and more rarely pulmonary arterial hypertension (PAH). Here, we aimed to understand the impact of ALK1 mutations on BMP9 and BMP10 transcriptomic responses in endothelial cells. Endothelial colony-forming cells (ECFCs) and microvascular endothelial cells (HMVECs) carrying loss of function ALK1 mutations were isolated from newborn HHT and adult PAH donors, respectively. RNA-sequencing was performed on each type of cells compared to controls following an 18 h stimulation with BMP9 or BMP10. In control ECFCs, BMP9 and BMP10 stimulations induced similar transcriptomic responses with around 800 differentially expressed genes (DEGs). ALK1-mutated ECFCs unexpectedly revealed highly similar transcriptomic profiles to controls, both at the baseline and upon stimulation, and normal activation of Smad1/5 that could not be explained by a compensation in cell-surface ALK1 level. Conversely, PAH HMVECs revealed strong transcriptional dysregulations compared to controls with > 1200 DEGs at the baseline. Consequently, because our study involved two variables, ALK1 genotype and BMP stimulation, we performed two-factor differential expression analysis and identified 44 BMP9-dysregulated genes in mutated HMVECs, but none in ECFCs. Yet, the impaired regulation of at least one hit, namely lunatic fringe (LFNG), was validated by RT-qPCR in three different ALK1-mutated endothelial models. In conclusion, ALK1 heterozygosity only modified the BMP9/BMP10 regulation of few genes, including LFNG involved in NOTCH signaling. Future studies will uncover whether dysregulations in such hits are enough to promote HHT/PAH pathogenesis, making them potential therapeutic targets, or if second hits are necessary.
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Affiliation(s)
- T Al Tabosh
- Biosanté unit U1292, Grenoble Alpes University, INSERM, CEA, 38000, Grenoble, France
| | - H Liu
- Biosanté unit U1292, Grenoble Alpes University, INSERM, CEA, 38000, Grenoble, France
| | - D Koça
- Biosanté unit U1292, Grenoble Alpes University, INSERM, CEA, 38000, Grenoble, France
| | - M Al Tarrass
- Biosanté unit U1292, Grenoble Alpes University, INSERM, CEA, 38000, Grenoble, France
| | - L Tu
- Faculté de Médecine, Pulmonary Hypertension: Pathophysiology and Novel Therapies, Université Paris-Saclay, 94276, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 «Pulmonary Hypertension: Pathophysiology and Novel Therapies», Hôpital Marie Lannelongue, 92350, Le Plessis-Robinson, France
| | - S Giraud
- Genetics Department, Femme-Mère-Enfants Hospital, Hospices Civils de Lyon, 69677, Bron, France
| | - L Delagrange
- Genetics Department, Femme-Mère-Enfants Hospital, Hospices Civils de Lyon, 69677, Bron, France
- National Reference Center for HHT, 69677, Bron, France
| | - M Beaudoin
- Genetics Department, Femme-Mère-Enfants Hospital, Hospices Civils de Lyon, 69677, Bron, France
- National Reference Center for HHT, 69677, Bron, France
| | - S Rivière
- Internal Medicine Department, CHU of Montpellier, St Eloi Hospital and Center of Clinical Investigation, INSERM, CIC 1411, 34295, Montpellier Cedex 7, France
| | - V Grobost
- Internal Medicine Department, CHU Estaing, 63100, Clermont-Ferrand, France
| | - M Rondeau-Lutz
- Internal Medicine Department, University Hospital of Strasbourg, 67091, Strasbourg Cedex, France
| | - O Dupuis
- Hôpital Lyon SUD, Hospices Civils de Lyon, Université Claude Bernard Lyon 1, 69100, Villeurbanne, France
- Faculty of Medicine, Lyon University, 69921, Lyon, France
| | - N Ricard
- Biosanté unit U1292, Grenoble Alpes University, INSERM, CEA, 38000, Grenoble, France
| | - E Tillet
- Biosanté unit U1292, Grenoble Alpes University, INSERM, CEA, 38000, Grenoble, France
| | - P Machillot
- Biosanté unit U1292, Grenoble Alpes University, INSERM, CEA, 38000, Grenoble, France
| | - A Salomon
- Biosanté unit U1292, Grenoble Alpes University, INSERM, CEA, 38000, Grenoble, France
| | - C Picart
- Biosanté unit U1292, Grenoble Alpes University, INSERM, CEA, 38000, Grenoble, France
| | - C Battail
- Biosanté unit U1292, Grenoble Alpes University, INSERM, CEA, 38000, Grenoble, France
| | - S Dupuis-Girod
- Biosanté unit U1292, Grenoble Alpes University, INSERM, CEA, 38000, Grenoble, France
- Genetics Department, Femme-Mère-Enfants Hospital, Hospices Civils de Lyon, 69677, Bron, France
- National Reference Center for HHT, 69677, Bron, France
| | - C Guignabert
- Faculté de Médecine, Pulmonary Hypertension: Pathophysiology and Novel Therapies, Université Paris-Saclay, 94276, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 «Pulmonary Hypertension: Pathophysiology and Novel Therapies», Hôpital Marie Lannelongue, 92350, Le Plessis-Robinson, France
| | - A Desroches-Castan
- Biosanté unit U1292, Grenoble Alpes University, INSERM, CEA, 38000, Grenoble, France
| | - S Bailly
- Biosanté unit U1292, Grenoble Alpes University, INSERM, CEA, 38000, Grenoble, France.
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Bouyer M, Garot C, Machillot P, Vollaire J, Fitzpatrick V, Morand S, Boutonnat J, Josserand V, Bettega G, Picart C. 3D-printed scaffold combined to 2D osteoinductive coatings to repair a critical-size mandibular bone defect. Mater Today Bio 2021; 11:100113. [PMID: 34124641 PMCID: PMC8173095 DOI: 10.1016/j.mtbio.2021.100113] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/20/2021] [Accepted: 04/24/2021] [Indexed: 02/03/2023] Open
Abstract
The reconstruction of large bone defects (12 cm3) remains a challenge for clinicians. We developed a new critical-size mandibular bone defect model on a minipig, close to human clinical issues. We analyzed the bone reconstruction obtained by a 3D-printed scaffold made of clinical-grade polylactic acid (PLA), coated with a polyelectrolyte film delivering an osteogenic bioactive molecule (BMP-2). We compared the results (computed tomography scans, microcomputed tomography scans, histology) to the gold standard solution, bone autograft. We demonstrated that the dose of BMP-2 delivered from the scaffold significantly influenced the amount of regenerated bone and the repair kinetics, with a clear BMP-2 dose-dependence. Bone was homogeneously formed inside the scaffold without ectopic bone formation. The bone repair was as good as for the bone autograft. The BMP-2 doses applied in our study were reduced 20- to 75-fold compared to the commercial collagen sponges used in the current clinical applications, without any adverse effects. Three-dimensional printed PLA scaffolds loaded with reduced doses of BMP-2 may be a safe and simple solution for large bone defects faced in the clinic.
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Affiliation(s)
- M. Bouyer
- CEA, CNRS, Université de Grenoble Alpes, ERL5000 BRM, IRIG Institute, 17 Rue des Martyrs, F-38054, Grenoble, France
- CNRS and Grenoble Institute of Engineering, UMR5628, LMGP, 3 Parvis Louis Néel, F-38016, Grenoble, France
- Université Grenoble Alpes, Institut Albert Bonniot, F-38000, Grenoble, France
- Clinique Générale d’Annecy, 4 Chemin de la Tour la Reine, 74000, Annecy, France
| | - C. Garot
- CEA, CNRS, Université de Grenoble Alpes, ERL5000 BRM, IRIG Institute, 17 Rue des Martyrs, F-38054, Grenoble, France
- CNRS and Grenoble Institute of Engineering, UMR5628, LMGP, 3 Parvis Louis Néel, F-38016, Grenoble, France
| | - P. Machillot
- CEA, CNRS, Université de Grenoble Alpes, ERL5000 BRM, IRIG Institute, 17 Rue des Martyrs, F-38054, Grenoble, France
- CNRS and Grenoble Institute of Engineering, UMR5628, LMGP, 3 Parvis Louis Néel, F-38016, Grenoble, France
| | - J. Vollaire
- Université Grenoble Alpes, Institut Albert Bonniot, F-38000, Grenoble, France
- INSERM U1209, Institut Albert Bonniot, F-38000, Grenoble, France
| | - V. Fitzpatrick
- CNRS and Grenoble Institute of Engineering, UMR5628, LMGP, 3 Parvis Louis Néel, F-38016, Grenoble, France
| | - S. Morand
- CEA, CNRS, Université de Grenoble Alpes, ERL5000 BRM, IRIG Institute, 17 Rue des Martyrs, F-38054, Grenoble, France
- CNRS and Grenoble Institute of Engineering, UMR5628, LMGP, 3 Parvis Louis Néel, F-38016, Grenoble, France
- Service de Chirurgie Maxillo-faciale, Centre Hospitalier Annecy Genevois, 1 Avenue de l'hôpital, 74370, Epagny Metz-Tessy, France
| | - J. Boutonnat
- Unité Médico-technique d’Histologie Cytologie Expérimentale, Faculté de Médecine, Université Joseph Fourier, 38700, La Tronche, France
- Département d’Anatomie et Cytologie Pathologique, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire de Grenoble, France
| | - V. Josserand
- Université Grenoble Alpes, Institut Albert Bonniot, F-38000, Grenoble, France
- INSERM U1209, Institut Albert Bonniot, F-38000, Grenoble, France
| | - G. Bettega
- Université Grenoble Alpes, Institut Albert Bonniot, F-38000, Grenoble, France
- INSERM U1209, Institut Albert Bonniot, F-38000, Grenoble, France
- Service de Chirurgie Maxillo-faciale, Centre Hospitalier Annecy Genevois, 1 Avenue de l'hôpital, 74370, Epagny Metz-Tessy, France
- Corresponding author.
| | - C. Picart
- CEA, CNRS, Université de Grenoble Alpes, ERL5000 BRM, IRIG Institute, 17 Rue des Martyrs, F-38054, Grenoble, France
- CNRS and Grenoble Institute of Engineering, UMR5628, LMGP, 3 Parvis Louis Néel, F-38016, Grenoble, France
- Institut Universitaire de France, 1 Rue Descartes, 75231, Paris Cedex 05, France
- Corresponding author.
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Etienne O, Picart C, Taddei C, Keller P, Hubsch E, Schaaf P, Voegel JC, Haikel Y, Ogier JA, Egles C. Polyelectrolyte Multilayer Film Coating and Stability at the Surfaces of Oral Prosthesis Base Polymers: an in vitro and in vivo Study. J Dent Res 2016; 85:44-8. [PMID: 16373679 DOI: 10.1177/154405910608500107] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A new type of coating involving a layer-by-layer technique has been recently reported. This coating is composed of a polyelectrolyte multilayer film that confers specific properties on surfaces to which it is applied. Here, we studied the applicability of such a technique to the coating of oral prostheses, by first testing the construction of polyelectrolyte multilayer films on several polymers used in oral prosthesis bases, and, subsequently, by studying the stability of these coatings in vitro, in human saliva, and in vivo in a rat model. We demonstrated that the multilayered films are able to coat the surfaces of all tested polymers completely, thus increasing their wettability. We also showed that saliva does not degrade the film after 7 days in vitro and after 4 days in vivo. Taken together, our results establish that the layer-by-layer technique is suitable for the coating of oral devices.
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Affiliation(s)
- O Etienne
- Institut National de la Santé et de la Recherche Médicale, Unité 595, 11, rue Humann, 67085 Strasbourg Cedex, France
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Cariou M, Picart C, Bommelaere F, Nousbaum JB, Robaszkiewicz M. Impact de la baisse de participation au dépistage organisé du cancer colorectal, Brest, France. Rev Epidemiol Sante Publique 2016. [DOI: 10.1016/j.respe.2016.06.218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Liu X, Dalonneau F, Fourel L, Sadir R, Lortat-Jacob H, Albiges-Rizo C, Picart C. 276 Delivery of SDF-1α in a matrix-bound manner on cancer cell behaviors: Underlying molecular mechanisms. Eur J Cancer 2015. [DOI: 10.1016/s0959-8049(16)30161-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Kalman B, Monge C, Bigot A, Mouly V, Picart C, Boudou T. Engineering human 3D micromuscles with co-culture of fibroblasts and myoblasts. Comput Methods Biomech Biomed Engin 2015; 18 Suppl 1:1960-1. [DOI: 10.1080/10255842.2015.1069557] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- B. Kalman
- Université Grenoble Alpes, Grenoble, France
- Centre National de la Recherche Scientifique, Grenoble, France
| | - C. Monge
- Université Grenoble Alpes, Grenoble, France
- Centre National de la Recherche Scientifique, Grenoble, France
| | - A. Bigot
- INSERM U974, Institut de Myologie, Paris, France
| | - V. Mouly
- INSERM U974, Institut de Myologie, Paris, France
| | - C. Picart
- Université Grenoble Alpes, Grenoble, France
- Centre National de la Recherche Scientifique, Grenoble, France
| | - T. Boudou
- Université Grenoble Alpes, Grenoble, France
- Centre National de la Recherche Scientifique, Grenoble, France
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7
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Hamard-Peron E, Juilliard F, Saad JS, Roy C, Roingeard P, Summers MF, Darlix JL, Picart C, Muriaux D. Targeting of MuLV Gag to the plasma membrane is mediated by PI(4,5)P2 and PhosphatidylSerine. Retrovirology 2009. [PMCID: PMC2766969 DOI: 10.1186/1742-4690-6-s2-o15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Brunot C, Grosgogeat B, Picart C, Lagneau C, Jaffrezic-Renault N, Ponsonnet L. Response of fibroblast activity and polyelectrolyte multilayer films coating titanium. Dent Mater 2008; 24:1025-35. [PMID: 18237774 DOI: 10.1016/j.dental.2007.11.022] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Revised: 06/07/2007] [Accepted: 11/21/2007] [Indexed: 11/17/2022]
Abstract
OBJECTIVES The study of surface properties is a recent and crucial issue in the biomaterial fields applied to Odontology. The reference biomaterial in dental implantology is titanium. The principal objective is a perfect bio-integration in the oral ecosystem, both in terms of mucosal and bone tissues. The aim of this work was to optimize the tissue-titanium interface by applying polyelectrolyte multilayer films on the surface of titanium. METHODS The experimental study was undertaken on pure titanium samples. Two types of film ending with polycations or polyanions were selected. Both film types were built with a first poly(ethyleneimine) (PEI) base layer and composed either of poly(styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) or of hyaluronic acid (HA) and poly(l-lysine) (PLL) layers. Final architectures were as follows: PEI-(PSS/PAH)(10), or PEI-(PSS/PAH)(10)-PSS, or chemically cross-linked PEI-(HA/PLL)(10) or PEI-(HA/PLL)(10)-HA. An analysis of the physicochemical characteristics of the surfaces was carried out by tensiometry measurements (dynamic contact angle, wettability, contact angle hysteresis) and atomic force microscopy. A biological study with human fibroblasts was followed over a 7-day culture period at days 0, 2, 4 and 7 to observe the cellular response in terms of morphology (scanning electron microscopy) and viability (Mosmann's test). RESULTS The results showed that polyelectrolyte multilayer films could be successfully deposited onto titanium as previously described for glass or composite. Fibroblast adhesion and proliferation was strongly dependent on film type. SEM observations of cells on the different films agreed with the viability cell test. Furthermore, films containing PSS/PAH generated a better cellular response than films containing cross-linked HA/PLL. CONCLUSION PSS/PAH polyelectrolyte films coating titanium could represent a new approach for oral bio-integration with great potential for clinical application in the fields of dental implantology. More particularly, the specific biofunctionalization of PSS/PAH films coating titanium could be envisioned by introducing layers of molecules that encourage the bio-integration process between the films.
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Affiliation(s)
- C Brunot
- Laboratoire des Multimatériaux et des Interfaces, UMR CNRS 5615, Université de Lyon, Université Lyon 1, Faculté d'Odontologie, Rue Guillaume Paradin, F-69372 Lyon Cedex 08, France.
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Boudou T, Ohayon J, Picart C, Tracqui P. Influences of adhesion area and biological sample size on the estimation of Young's modulus and Poisson's ratio assessed by micropipette aspiration technique. ACTA ACUST UNITED AC 2007; 2007:5391-4. [PMID: 18003227 DOI: 10.1109/iembs.2007.4353561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The micropipette aspiration experiment remains a widely used micromanipulation technique for quantifying the mechanical properties of biological samples. Our study extends previous results by investigating the influence of sample size and adhesion area on the mechanical response of compressible thin biological samples. We thus defined a nonlinear relationship between aspirated length, Young's modulus, Poisson's ratio and sample thickness which allowed us to develop an original experimental protocol for simultaneous quantification of the Poisson's ratio and Young's modulus of adherent samples. We first validated our method by characterizing mechanical properties of polyacrylamide gels with tunable stiffness. We then considered application of these results to the quantification of cell elasticity, focusing on the influence of cell adhesion area onto the measured apparent cell stiffness.
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Affiliation(s)
- T Boudou
- Laboratoire TIMC-IMAG, Dynacell, Centre National de la Recherche Scientifique, UMR 5525, IN3S, 38706 La Tronche Cedex, France.
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Boudou T, Ohayon J, Picart C, Tracqui P. Nonlinear elastic behavior of polyacrylamide gels assessed by micropipette aspiration technique. Comput Methods Biomech Biomed Engin 2007. [DOI: 10.1080/10255840701478554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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Mhamdi L, Picart C, Lagneau C, Othmane A, Grosgogeat B, Jaffrezic-Renault N, Ponsonnet L. Study of the polyelectrolyte multilayer thin films' properties and correlation with the behavior of the human gingival fibroblasts. Materials Science and Engineering: C 2006. [DOI: 10.1016/j.msec.2005.10.049] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Richert L, Schneider A, Vautier D, Jessel N, Voegel JC, Picart C. Influence of cross-linking on polyelectrolytes multilayer, physical and biological aspect. Comput Methods Biomech Biomed Engin 2005. [DOI: 10.1080/10255840512331389127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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13
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Etienne O, Picart C, Taddei C, Haikel Y, Dimarcq JL, Schaaf P, Voegel JC, Ogier JA, Egles C. Multilayer polyelectrolyte films functionalized by insertion of defensin: a new approach to protection of implants from bacterial colonization. Antimicrob Agents Chemother 2004; 48:3662-9. [PMID: 15388417 PMCID: PMC521874 DOI: 10.1128/aac.48.10.3662-3669.2004] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infection of implanted materials by bacteria constitutes one of the most serious complications following prosthetic surgery. In the present study, we developed a new strategy based on the insertion of an antimicrobial peptide (defensin from Anopheles gambiae mosquitoes) into polyelectrolyte multilayer films built by the alternate deposition of polyanions and polycations. Quartz crystal microbalance and streaming potential measurements were used to follow step by step the construction of the multilayer films and embedding of the defensin within the films. Antimicrobial assays were performed with two strains: Micrococcus luteus (a gram-positive bacterium) and Escherichia coli D22 (a gram-negative bacterium). The inhibition of E. coli D22 growth at the surface of defensin-functionalized films was found to be 98% when 10 antimicrobial peptide layers were inserted in the film architecture. Noticeably, the biofunctionalization could be achieved only when positively charged poly(l-lysine) was the outermost layer of the film. On the basis of the results of bacterial adhesion experiments observed by confocal or electron microscopy, these observations could result from the close interaction of the bacteria with the positively charged ends of the films, which allows defensin to interact with the bacterial membrane structure. These results open new possibilities for the use of such easily built and functionalized architectures onto any type of implantable biomaterial. The modified surfaces are active against microbial infection and represent a novel means of local host protection.
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Affiliation(s)
- O Etienne
- Institut National de la Santé et de la Recherche Médicale, Unité 595, 11, rue Humann, 67085 Strasbourg Cedex, France.
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Boulmedais F, Frisch B, Etienne O, Lavalle P, Picart C, Ogier J, Voegel JC, Schaaf P, Egles C. Polyelectrolyte multilayer films with pegylated polypeptides as a new type of anti-microbial protection for biomaterials. Biomaterials 2004; 25:2003-11. [PMID: 14741614 DOI: 10.1016/j.biomaterials.2003.08.039] [Citation(s) in RCA: 190] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Adhesion of bacteria at the surface of implanted materials is the first step in microbial infection, leading to post-surgical complications. In order to reduce this adhesion, we show that poly(L-lysine)/poly(L-glutamic acid) (PLL/PGA) multilayers ending by several PLL/PGA-g-PEG bilayers can be used, PGA-g-PEG corresponding to PGA grafted by poly(ethylene glycol). Streaming potential and quartz crystal microbalance-dissipation measurements were used to characterize the buildup of these films. The multilayer films terminated by PGA and PGA-g-PEG were found to adsorb an extremely small amount of serum proteins as compared to a bare silica surface but the PGA ending films do not reduce bacterial adhesion. On the other hand, the adhesion of Escherichia coli bacteria is reduced by 72% on films ending by one (PLL/PGA-g-PEG) bilayer and by 92% for films ending by three (PLL/PGA-g-PEG) bilayers compared to bare substrate. Thus, our results show the ability of PGA-g-PEG to be inserted into multilayer films and to drastically reduce both protein adsorption and bacterial adhesion. This kind of anti-adhesive films represents a new and very simple method to coat any type of biomaterials for protection against bacterial adhesion and therefore limiting its pathological consequences.
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Affiliation(s)
- F Boulmedais
- Institut Charles Sadron, UPR 22 CNRS, 6 rue Boussingault, 67083 Strasbourg Cedex, France
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15
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Boura C, Menu P, Payan E, Picart C, Voegel JC, Muller S, Stoltz JF. Endothelial cells grown on thin polyelectrolyte mutlilayered films: an evaluation of a new versatile surface modification. Biomaterials 2003; 24:3521-30. [PMID: 12809781 DOI: 10.1016/s0142-9612(03)00214-x] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Endothelial cell seeding constitutes an appreciated method to improve blood compatibility of small-diameter vascular grafts. In this study, we report the development of a simple innovative technique based on multilayered polyelectrolyte films as cell adhesive substrates. Polyelectrolyte multilayered films ending by poly(sodium-4-styrenesulfonate)/poly(allylamine hydrochloride) (PSS/PAH) or poly(L-glutamic acid)/poly(D-lysine) (PGA/PDL) could enhance cell adhesion by modification of the physico-chemical properties of the surface. The biological responses of human umbilical vein endothelial cells seeded on the polyelectrolyte multilayer films, on PDL or PAH monolayers, and on control surfaces, were evaluated in terms of initial attachment, growth, cellular metabolic activity, endothelial phenotype, and adhesion. The results showed that polyelectrolyte multilayers neither induce cytotoxic effects nor alter the phenotype of the endothelial cells. The polyelectrolyte multilayered films enhanced initial cell attachment as compared to the polyelectrolyte monolayer. Cell growth observed on the films was similar to that on TCPS. Among the different coating tested, the film ending by PSS/PAH exhibited an excellent cellular biocompatibility and appeared to be the most interesting surface in terms of cellular adhesion and growth. Such films could be used to cover hydrophobic (cell resistant) substrates in order to promote cell colonization, thereby constituting an excellent material for endothelial cell seeding.
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Affiliation(s)
- C Boura
- Laboratoire de Mécanique et Ingénierie Cellulaire et Tissulaire, UMR CNRS-INPL-UHP 7563 et IFR 111, Faculté de Médecine, Bât E, 9 Avenue de la forêt de Haye, 54505 Vandoeuvre-lès-Nancy, France
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Hemmerlé J, Picart C, Gergely C, Schaaf P, Stoltz JF, Voegel JC, Senger B. Modeling of the detachment of a molecule from a surface: illustration of the "Bell-Evans effect". Biorheology 2003; 40:149-60. [PMID: 12454399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
This article deals with the modeling of the detachment of a molecule initially adsorbed on a surface and submitted to an external force whose strength increases with time. By means of an atomic force microscope (AFM), it is possible to measure the force when the molecule separates from the substrate. However, it is known that this force depends to a large extend on the rate at which the pulling force is applied ("Bell-Evans effect"). Two models are described to illustrate this behavior. First, a random walk approach is suggested to reveal the fundamental principle of the escape over a time-dependent energy barrier. Second, a multi bead-and-spring model is proposed to mimic the AFM experiment and numerical simulations, based on Brownian dynamics, are performed.
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Affiliation(s)
- J Hemmerlé
- Institut National de la Santé et de la Recherche Médicale, Unité 424, UFR d'Odontologie, Université Louis Pasteur, 11, rue Humann, 67085 Strasbourg Cedex, France
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Richert L, Lavalle P, Vautier D, Senger B, Stoltz JF, Schaaf P, Voegel JC, Picart C. Cell interactions with polyelectrolyte multilayer films. Biomacromolecules 2002; 3:1170-8. [PMID: 12425653 DOI: 10.1021/bm0255490] [Citation(s) in RCA: 201] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The short-term interactions of chondrosarcoma cells with polyelectrolyte multilayer films built up by the alternate adsorption of poly(L-lysine) (PLL) and poly(L-glutamic acid) (PGA) was studied in the presence and in the absence of serum. The films and their interaction with serum proteins were first characterized by means of optical waveguide lightmode spectroscopy, quartz crystal microbalance, and zeta potential measurements. In a serum-containing medium, the detachment forces measured by the micropipet technique were about eight times smaller on PGA-ending than on PLL-ending films. For these latter ones, the adhesion force decreased when the film thickness increased. In a serum-free medium, the differences between the negative- and positive-ending films were enhanced: adhesion forces on PLL-ending films were 40-100% higher, whereas no cellular adherence was found on PGA-terminating films. PGA-ending films were found to prevent the adsorption of serum proteins, whereas important protein adsorption was always observed on PLL-ending films. These results show how cell interactions with polyelectrolyte films can be tuned by the type of the outermost layer, the presence of proteins, and the number of layers in the film.
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Affiliation(s)
- L Richert
- INSERM Unité 424, UFR d'Odontologie, Université Louis Pasteur, 11 rue Humann, F-67085 Strasbourg Cedex, France
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Picart C, Mutterer J, Richert L, Luo Y, Prestwich GD, Schaaf P, Voegel JC, Lavalle P. Molecular basis for the explanation of the exponential growth of polyelectrolyte multilayers. Proc Natl Acad Sci U S A 2002; 99:12531-5. [PMID: 12237412 PMCID: PMC130494 DOI: 10.1073/pnas.202486099] [Citation(s) in RCA: 784] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2002] [Accepted: 08/12/2002] [Indexed: 11/18/2022] Open
Abstract
The structure of poly(l-lysine) (PLL)/hyaluronan (HA) polyelectrolyte multilayers formed by electrostatic self-assembly is studied by using confocal laser scanning microscopy, quartz crystal microbalance, and optical waveguide lightmode spectroscopy. These films exhibit an exponential growth regime where the thickness increases exponentially with the number of deposited layers, leading to micrometer thick films. Previously such a growth regime was suggested to result from an "in" and "out" diffusion of the PLL chains through the film during buildup, but direct evidence was lacking. The use of dye-conjugated polyelectrolytes now allows a direct three-dimensional visualization of the film construction by introducing fluorescent polyelectrolytes at different steps during the film buildup. We find that, as postulated, PLL diffuses throughout the film down into the substrate after each new PLL injection and out of the film after each PLL rinsing and further after each HA injection. As PLL reaches the outer layer of the film it interacts with the incoming HA, forming the new HA/PLL layer. The thickness of this new layer is thus proportional to the amount of PLL that diffuses out of the film during the buildup step, which explains the exponential growth regime. HA layers are also visualized but no diffusion is observed, leading to a stratified film structure. We believe that such a diffusion-based buildup mechanism explains most of the exponential-like growth processes of polyelectrolyte multilayers reported in the literature.
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Affiliation(s)
- C Picart
- Institut National de la Santé et de la Recherche Médicale, Unité 424, Centre de Recherche Odontologique, Université Louis Pasteur, 11 Rue Humann, 67085 Strasbourg Cedex, France
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Lavalle P, Gergely C, Cuisinier FJG, Decher G, Schaaf P, Voegel JC, Picart C. Comparison of the Structure of Polyelectrolyte Multilayer Films Exhibiting a Linear and an Exponential Growth Regime: An in Situ Atomic Force Microscopy Study. Macromolecules 2002. [DOI: 10.1021/ma0119833] [Citation(s) in RCA: 450] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ph. Lavalle
- INSERM Unité 424, Fédération de Recherches “Odontologie”, Université Louis Pasteur, 11 rue Humann, F-67085 Strasbourg Cedex, France; Institut Charles Sadron (CNRS UPR 22), 6 rue Boussingault, F-67083 Strasbourg Cedex, France; Université Louis Pasteur, Faculté de Chimie, 1 rue Blaise Pascal, F-67008 Strasbourg Cedex, France; and Ecole Européenne de Chimie, Polymères et Matériaux de Strasbourg, 25, rue Becquerel, F-67087 Strasbourg Cedex 2, France
| | - C. Gergely
- INSERM Unité 424, Fédération de Recherches “Odontologie”, Université Louis Pasteur, 11 rue Humann, F-67085 Strasbourg Cedex, France; Institut Charles Sadron (CNRS UPR 22), 6 rue Boussingault, F-67083 Strasbourg Cedex, France; Université Louis Pasteur, Faculté de Chimie, 1 rue Blaise Pascal, F-67008 Strasbourg Cedex, France; and Ecole Européenne de Chimie, Polymères et Matériaux de Strasbourg, 25, rue Becquerel, F-67087 Strasbourg Cedex 2, France
| | - F. J. G. Cuisinier
- INSERM Unité 424, Fédération de Recherches “Odontologie”, Université Louis Pasteur, 11 rue Humann, F-67085 Strasbourg Cedex, France; Institut Charles Sadron (CNRS UPR 22), 6 rue Boussingault, F-67083 Strasbourg Cedex, France; Université Louis Pasteur, Faculté de Chimie, 1 rue Blaise Pascal, F-67008 Strasbourg Cedex, France; and Ecole Européenne de Chimie, Polymères et Matériaux de Strasbourg, 25, rue Becquerel, F-67087 Strasbourg Cedex 2, France
| | - G. Decher
- INSERM Unité 424, Fédération de Recherches “Odontologie”, Université Louis Pasteur, 11 rue Humann, F-67085 Strasbourg Cedex, France; Institut Charles Sadron (CNRS UPR 22), 6 rue Boussingault, F-67083 Strasbourg Cedex, France; Université Louis Pasteur, Faculté de Chimie, 1 rue Blaise Pascal, F-67008 Strasbourg Cedex, France; and Ecole Européenne de Chimie, Polymères et Matériaux de Strasbourg, 25, rue Becquerel, F-67087 Strasbourg Cedex 2, France
| | - P. Schaaf
- INSERM Unité 424, Fédération de Recherches “Odontologie”, Université Louis Pasteur, 11 rue Humann, F-67085 Strasbourg Cedex, France; Institut Charles Sadron (CNRS UPR 22), 6 rue Boussingault, F-67083 Strasbourg Cedex, France; Université Louis Pasteur, Faculté de Chimie, 1 rue Blaise Pascal, F-67008 Strasbourg Cedex, France; and Ecole Européenne de Chimie, Polymères et Matériaux de Strasbourg, 25, rue Becquerel, F-67087 Strasbourg Cedex 2, France
| | - J. C. Voegel
- INSERM Unité 424, Fédération de Recherches “Odontologie”, Université Louis Pasteur, 11 rue Humann, F-67085 Strasbourg Cedex, France; Institut Charles Sadron (CNRS UPR 22), 6 rue Boussingault, F-67083 Strasbourg Cedex, France; Université Louis Pasteur, Faculté de Chimie, 1 rue Blaise Pascal, F-67008 Strasbourg Cedex, France; and Ecole Européenne de Chimie, Polymères et Matériaux de Strasbourg, 25, rue Becquerel, F-67087 Strasbourg Cedex 2, France
| | - C. Picart
- INSERM Unité 424, Fédération de Recherches “Odontologie”, Université Louis Pasteur, 11 rue Humann, F-67085 Strasbourg Cedex, France; Institut Charles Sadron (CNRS UPR 22), 6 rue Boussingault, F-67083 Strasbourg Cedex, France; Université Louis Pasteur, Faculté de Chimie, 1 rue Blaise Pascal, F-67008 Strasbourg Cedex, France; and Ecole Européenne de Chimie, Polymères et Matériaux de Strasbourg, 25, rue Becquerel, F-67087 Strasbourg Cedex 2, France
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Schwinté P, Voegel JC, Picart C, Haikel Y, Schaaf P, Szalontai B. Stabilizing Effects of Various Polyelectrolyte Multilayer Films on the Structure of Adsorbed/Embedded Fibrinogen Molecules: An ATR−FTIR Study. J Phys Chem B 2001. [DOI: 10.1021/jp0123031] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- P. Schwinté
- Contribution from the Unité de Formation et de Recherches “Odontologie” U424 INSERM, Université Louis Pasteur (ULP), 11 rue Humann, 67085 Strasbourg Cedex, France, Institut Charles Sadron (CNRS−ULP), 6 rue Boussingault, 67083 Strasbourg Cedex, France, and Institute of Biophysics, Biological Research Center (BRC), Hungarian Academy of Sciences, H-6701 Szeged, Temesvári krt. 62, P.O.B. 521, Hungary
| | - J.-C. Voegel
- Contribution from the Unité de Formation et de Recherches “Odontologie” U424 INSERM, Université Louis Pasteur (ULP), 11 rue Humann, 67085 Strasbourg Cedex, France, Institut Charles Sadron (CNRS−ULP), 6 rue Boussingault, 67083 Strasbourg Cedex, France, and Institute of Biophysics, Biological Research Center (BRC), Hungarian Academy of Sciences, H-6701 Szeged, Temesvári krt. 62, P.O.B. 521, Hungary
| | - C. Picart
- Contribution from the Unité de Formation et de Recherches “Odontologie” U424 INSERM, Université Louis Pasteur (ULP), 11 rue Humann, 67085 Strasbourg Cedex, France, Institut Charles Sadron (CNRS−ULP), 6 rue Boussingault, 67083 Strasbourg Cedex, France, and Institute of Biophysics, Biological Research Center (BRC), Hungarian Academy of Sciences, H-6701 Szeged, Temesvári krt. 62, P.O.B. 521, Hungary
| | - Y. Haikel
- Contribution from the Unité de Formation et de Recherches “Odontologie” U424 INSERM, Université Louis Pasteur (ULP), 11 rue Humann, 67085 Strasbourg Cedex, France, Institut Charles Sadron (CNRS−ULP), 6 rue Boussingault, 67083 Strasbourg Cedex, France, and Institute of Biophysics, Biological Research Center (BRC), Hungarian Academy of Sciences, H-6701 Szeged, Temesvári krt. 62, P.O.B. 521, Hungary
| | - P. Schaaf
- Contribution from the Unité de Formation et de Recherches “Odontologie” U424 INSERM, Université Louis Pasteur (ULP), 11 rue Humann, 67085 Strasbourg Cedex, France, Institut Charles Sadron (CNRS−ULP), 6 rue Boussingault, 67083 Strasbourg Cedex, France, and Institute of Biophysics, Biological Research Center (BRC), Hungarian Academy of Sciences, H-6701 Szeged, Temesvári krt. 62, P.O.B. 521, Hungary
| | - B. Szalontai
- Contribution from the Unité de Formation et de Recherches “Odontologie” U424 INSERM, Université Louis Pasteur (ULP), 11 rue Humann, 67085 Strasbourg Cedex, France, Institut Charles Sadron (CNRS−ULP), 6 rue Boussingault, 67083 Strasbourg Cedex, France, and Institute of Biophysics, Biological Research Center (BRC), Hungarian Academy of Sciences, H-6701 Szeged, Temesvári krt. 62, P.O.B. 521, Hungary
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Picart C, Ladam G, Senger B, Voegel JC, Schaaf P, Cuisinier FJG, Gergely C. Determination of structural parameters characterizing thin films by optical methods: A comparison between scanning angle reflectometry and optical waveguide lightmode spectroscopy. J Chem Phys 2001. [DOI: 10.1063/1.1375156] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abstract
The red cell's spectrin-actin network is known to sustain local states of shear, dilation, and condensation, and yet the short actin filaments are found to maintain membrane-tangent and near-random azimuthal orientations. When calibrated with polarization results for single actin filaments, imaging of micropipette-deformed red cell ghosts has allowed an assessment of actin orientations and possible reorientations in the network. At the hemispherical cap of the aspirated projection, where the network can be dilated severalfold, filaments have the same membrane-tangent orientation as on a relatively unstrained portion of membrane. Likewise, over the length of the network projection pulled into the micropipette, where the network is strongly sheared in axial extension and circumferential contraction, actin maintains its tangent orientation and is only very weakly aligned with network extension. Similar results are found for the integral membrane protein Band 3. Allowing for thermal fluctuations, we deduce a bound for the effective coupling constant, alpha, between network shear and azimuthal orientation of the protofilament. The finding that alpha must be about an order of magnitude or more below its tight-coupling value illustrates how nanostructural kinematics can decouple from more macroscopic responses. Monte Carlo simulations of spectrin-actin networks at approximately 10-nm resolution further support this conclusion and substantiate an image of protofilaments as elements of a high-temperature spin glass.
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Affiliation(s)
- C Picart
- Institute for Medicine and Engineering, and School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Carpentier PH, Imbert B, Picart C, Brasseur S, Malterre C. [Morphometric analysis of erythrocyte aggregates in vitro: pharmacological application with buflomedil]. J Mal Vasc 2000; 25:356-359. [PMID: 11148398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Erythrocyte aggregation is usually evaluated through indirect measurements such as the sedimentation rate and rheometric measurements of aggregation and disaggregation thresholds. The aim of this study was a preliminary evaluation of a morphometric approach of aggregates in vitro. A sample of blood (on EDTA) was examined under the microscope, and a picture with magnification X 640 was obtained after stabilization of the cellular structure. The digital image was analyzed with a home made dedicated software that allows the measurement of the cellular density and the evaluation of several shape parameters. Ten samples obtained from different donors were analysed within one hour after blood withdrawal and 24 hours later (preservation temperature: 4 degrees C), with and without adjunction of Buflomedil (4 microg/ml). Results showed an important anti-aggregant effect of Buflomedil administrated in these conditions, both on fresh and preserved blood (p<10(-3)). These results illustrate the potential interest of a morphometric approach to erythrocyte aggregation. They show new pharmacological properties of Buflomedil administered in vitro, which have to be confirmed with a therapeutic administration of the compound.
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Affiliation(s)
- P H Carpentier
- Laboratoire de Rhéologie, UMR CNRS Université J. Fourier, 38041 Grenoble Cedex.
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Abstract
The short actin filaments in the erythrocyte's membrane skeleton are shown to be largely oriented tangent to the lipid bilayer. Actin "proto"-filaments have previously been described as junctional centers intertriangulated by spectrin; however, the protofilaments may simultaneously serve as pinning centers between the network and the overlying bilayer. The latter function now seems of particular importance because near-normal network assembly has been reported with transgenic mouse sphero-erythrocytes that lack the primary linkage protein Band 3. To assess possible physical constraints on actin protofilaments in intact membranes, fluorescence polarization microscopy (FPM) has been used to study rhodamine phalloidin-labeled red cell ghosts. A basis for interpreting FPM images of cells is provided by FPM applied to isolated actin filaments. These are labeled with the same rhodamine probes and imaged at various orientations with respect to the polarizers, including filament orientations perpendicular to the image plane. High aperture and fluorophore conjugation effects are found to be minimal, enabling development of a simple, semi-empirical model which indicates that protofilaments are generally within approximately 20 degrees of the membrane tangent plane.
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Affiliation(s)
- C Picart
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6315, USA
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Ra HJ, Picart C, Feng H, Sweeney HL, Discher DE. Muscle cell peeling from micropatterned collagen: direct probing of focal and molecular properties of matrix adhesion. J Cell Sci 1999; 112 ( Pt 10):1425-36. [PMID: 10212137 DOI: 10.1242/jcs.112.10.1425] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To quantitatively elucidate attributes of myocyte-matrix adhesion, muscle cells were controllably peeled from narrow strips of collagen-coated glass. Initial growth of primary quail myoblasts on collagen strips was followed by cell alignment, elongation and end-on fusion between neighbors. This geometric influence on differentiation minimized lateral cell contact and cell branching, enabling detailed study of myocyte-matrix adhesion. A micropipette was used to pull back one end of a quasi-cylindrical cell while observing in detail the non-equilibrium detachment process. Peeling velocities fluctuated as focal roughness, microm in scale, was encountered along the detachment front. Nonetheless, mean peeling velocity (microm/second) generally increased with detachment force (nN), consistent with forced disruption of adhesion bonds. Immunofluorescence of beta1-integrins correlated with the focal roughness and appeared to be clustered in axially extended focal contacts. In addition, the peeling forces and rates were found to be moderately well described by a dynamical peeling model for receptor-based adhesion (Dembo, M., Torney, D. C., Saxman, K. and Hammer, D. (1988). Proc. R. Soc. Lond. B 234, 55–83). Estimates were thereby obtained for the spontaneous, molecular off-rate (kooff, (less than or equal to)10/seconds) and the receptor complex stiffness (kappa, approx. 10(−5)-10(−6) N/m) of adherent myocytes. Interestingly, the local stiffness is within the range of flexible proteins of the spectrin superfamily. The overall approach lends itself to elucidating the developing function of other structural and adhesive components of cells, particularly skeletal muscle cells with specialized components, such as the spectrin-homolog dystrophin and its membrane-linked receptor dystroglycan.
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Affiliation(s)
- H J Ra
- Biotechnology Program, School of Engineering and Applied Science, Dept of Physiology, Pennsylvania Muscle Institute and Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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Abstract
Blood is a weak percolating physical gel at low shear rates, in which clusters of aggregates can be reversibly disaggregated or formed again. This phenomenon is of potential importance in the microvascular pathophysiology of ischemic and vasospastic disorders such as systemic sclerosis. The aim of this work was to determine blood yield stress using low-shear-rate rheometry with a homemade roughened Couette device in 10 patients with systemic sclerosis compared with 10 healthy controls. Biochemical plasmatic parameters were assessed independently. Results showed a significantly increased stress (+56%, P < 0.05 at 60% hematocrit) for scleroderma patients. The best biochemical predictor for yield stress was the ratio of albumin to globulins; 69% of its variance was explained by plasmatic factors (albumin, fibrinogen, and globulins) in scleroderma patients and 23.4% in healthy controls. Additional microscopic observations showed different microstructures. These results support the hypothesis of an abnormal red blood cell organization process in scleroderma patients that could be partly responsible for the severity of ischemic complications of the disease.
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Affiliation(s)
- C Picart
- Laboratoire de Médecine Vasculaire, Université Joseph Fourier, Centre Hospitalier Universitaire, BP 217 X, 38043 Grenoble Cedex 9, France
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Picart C, Piau JM, Galliard H, Carpentier P. Blood low shear rate rheometry: influence of fibrinogen level and hematocrit on slip and migrational effects. Biorheology 1998; 35:335-53. [PMID: 10474659 DOI: 10.1016/s0006-355x(99)80015-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Red blood cell (RBC) aggregation is of prime importance in vivo and in vitro for low flow rates. It may be estimated by rheometrical measurements at low shear rates, but these are perturbed by slip and migrational effects which have already been highlighted in the past. These effects lead to a torque decay with time so that the true value of the stress at low shear rates may be greatly underestimated. Elevated aggregation being associated with different diseases, pathological blood samples show more pronounced perturbing effects and a strong time dependency in low shear rate rheometry. To test the dependence of slip and migrational effects on RBC aggregation, and particularly to determine the way in which they depend upon fibrinogen concentration ([Fb]), a home-made measuring system with roughened internal and external walls (170 microns roughness) was used to study low shear rate rheometry for RBC suspensions in PBS buffer containing albumin (at 50 g/l) and fibrinogen at various concentrations. The influences of hematocrit, shear rate, and fibrinogen concentration were investigated. Particular attention was paid to data acquisition at low shear rates (10(-3) s-1 to 3 x 10(-2) s-1). The combined influence of hematocrit and fibrinogen was investigated by adjusting hematocrit to 44 or 57% and fibrinogen concentration ([Fb]) to 3.0-4.5-6.5 g/l. Microscopic observations of the blood samples at rest were performed. They showed that different structures were formed according to fibrinogen concentration. The rheometrical measurements indicated that torque decay with shearing duration was strongly dependent on fibrinogen concentration and on shear rate at fixed hematocrit. Migrational and slip effects were more pronounced as shear rate decreased, fibrinogen concentration was raised, and hematocrit was lowered. The results have been explained on the basis of the expected microstructure of flowing blood in relation to the microscopic observations at rest.
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Affiliation(s)
- C Picart
- Laboratoire de Rhéologie, Université Joseph Fourier-Grenoble 1, Institut National Polytechnique de Grenoble, France.
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Picart C, Piau JM, Galliard H, Carpentier PH. [Threshold of shear stress in human blood for healthy and sick subjects]. J Mal Vasc 1998; 23:113-118. [PMID: 9608924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
It is now well recognized that blood is a yield stress fluid, that is to say that it will not flow below a critical threshold level of stress. This is reflected in vivo with a cessation of flow threshold, of great importance in circulatory physiology and pathophysiology. Values for yield stress obtained by different techniques are scarce. Rheometry at low shear rates is one method of obtaining values. After mitigating the slip effects on the walls of the rheometer, it has been possible to get an approximate value of the yield stress in human blood samples in controls and in ill subjects with different hematocrits. A Low Shear 40 rheometer with a controlled rotation speed was used. Home made geometries were used and the shear rate was varied in the range 10(-3) s-1-100 s-1. Fresh blood samples from healthy donors and patients were anticoagulated with EDTA. Suspensions of red cells in plasma were prepared by removing plasma. The measurements were made at 25 degrees C within four hours following blood sampling. Particular attention was paid to data acquisition at low shear rates (10(-3) s-1, 3.10(-3) s-1, 10(-2) s-1, 3.10(-2) s-1) with a computer linked to the rheometer. Shear stress approached a constant value at low shear rates for geometries with rough surfaces. Shear stress measured at 10(-3) s-1 was taken as an approximation of yield stress. Values were 5 to 6 mPa for hematocrit 60% and 20 to 25 mPa for hematocrit in the 80 to 90% range. For pathological blood samples, accurate measurements were made at shear rate as low as 0.01 s-1. Migrational effects were present at 10(-1) s-1 et 3.10(-3) s-1 but they could be greatly mitigated by the use of the 170 microns surface roughness.
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Affiliation(s)
- C Picart
- Laboratoire de Médecine Vasculaire, Université Joseph Fourier, CHU, Grenoble
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Picart C, Carpentier PH, Brasseur S, Galliard H, Piau JM. Systemic sclerosis: blood rheometry and laser Doppler imaging of digital cutaneous microcirculation during local cold exposure. Clin Hemorheol Microcirc 1998; 18:47-58. [PMID: 9653586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A combined study of microcirculation hemodynamics in vivo and blood rheometry has been carried out in patients with scleroderma compared to primary Raynaud's phenomenon (PRP) and healthy controls (HC). Laser Doppler perfusion imaging was used to assess superficial skin blood flow in the fingers before, during and after local cold exposure. Blood viscosity was measured at 19 and 37 degrees C. Dynamic and transient flows were also investigated. The scleroderma group showed a significantly lower level of perfusion before the cold test, that was further decreased during and after cold exposure, the difference with PRP being maximal during the rewarming period. It also showed a significantly increased viscosity (p < 0.05) at low shear rates. Hemorheological behavior of the PRP group was similar to the HC group. A significant negative correlation between the LDI perfusion and the apparent blood viscosity at low shear rates was found for the whole population. These findings suggest that rheological factors may be involved in the abnormal cold reactivity of patients with scleroderma.
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Affiliation(s)
- C Picart
- Laboratoire de Médecine Vasculaire, Université Joseph Fourier, Centre Hospitalier Universitaire, Grenoble, France
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