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Monzel C, Veschgini M, Madsen J, Lewis AL, Armes SP, Tanaka M. Fine Adjustment of Interfacial Potential between pH-Responsive Hydrogels and Cell-Sized Particles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:8689-8696. [PMID: 26190346 DOI: 10.1021/acs.langmuir.5b01896] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We quantitatively determined interfacial potentials between cell-sized particles and stimulus-responsive hydrogels using a microinterferometer. The hydrogel is based on physically interconnected ABA triblock copolymer micelles comprising an inner biocompatible PMPC block and two outer pH-responsive PDPA blocks. The out-of-plane temporal fluctuation in the position of the cell-sized particles was calculated from changes in the interference pattern measured by Reflection Interference Contrast Microscopy (RICM), thus yielding the particle-substrate interaction potential V (Δh). Measurements in pH buffers ranging from 7.0 to 7.8 resulted in a systematic reduction in height of the potential minima ⟨Δh⟩ and a concomitant increase in the potential curvature V″ (Δh). The experimental data were analyzed by applying the modified Ross and Pincus model for polyelectrolytes, while accounting for gravitation, lubrication and van der Waals interactions. Elastic moduli calculated from V″ (Δh) were in good agreement with those measured by Atomic Force Microscopy. The ability to fine-tune both the gel elasticity and the interfacial potential at around physiological pH makes such triblock copolymer hydrogels a promising biocompatible substrate for dynamic switching of cell-material interactions.
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Affiliation(s)
- Cornelia Monzel
- †Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg, Germany
| | - Mariam Veschgini
- †Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg, Germany
| | - Jeppe Madsen
- ‡Department of Chemistry, Dainton Building, University of Sheffield, Brook Hill, Sheffield, South Yorkshire, S3 7HF, United Kingdom
| | - Andrew L Lewis
- §Biocompatibles UK, Ltd., Chapman House, Farnham Business Park, Weydon Lane, Farnham, Surrey GU9 8 QL, United Kingdom
| | - Steven P Armes
- ‡Department of Chemistry, Dainton Building, University of Sheffield, Brook Hill, Sheffield, South Yorkshire, S3 7HF, United Kingdom
| | - Motomu Tanaka
- †Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg, Germany
- ∥Institute for Integrated Cell-Material Sciences (WPI iCeMS), Kyoto University, 606-8501, Kyoto, Japan
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Szczepanik AB, Dąbrowski WP, Szczepanik AM, Pielaciński K, Jaśkowiak W. Sclerotherapy Of Esophageal Varices In Severe Hemophilia A Patient And High Titer Inhibitor – Case Report. POLISH JOURNAL OF SURGERY 2015; 87:464-8. [DOI: 10.1515/pjs-2015-0089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Indexed: 11/15/2022]
Abstract
AbstractIn cirrhotic hemophilia patients bleeding from esophageal varices is a serious clinical condition due to congenital deficiency of clotting factors VIII or IX, decreased prothrombin synthesis and hypersplenic thrombocytopenia. In hemophiliac with high-titer inhibitor bypassing therapy is required with activated prothrombin complex concentrates (aPCC) or recombinant activated coagulation factor VII (rFVIIa). Doses and duration treatment with these agents following endoscopic treatment of esophageal varices have not been yet established.Authors report the first case of a severe hemophilia A patient with high titer inhibitor (40 BU) treated with repeated injection sclerotherapy. The patient was admitted with symptoms of massive esophageal variceal hemorrhage ceased with emergency sclerotherapy. Bypassing therapy was administered with aPCC at initial dose of 72.5 U/kg and then with average daily dose of 162 U/kg through 5 days. To achieved a total eradication of esophageal varices the patient was then subjected to four elective sclerotherapy procedures. Two were covered by aPCC with daily dose of 120 U/kg and 145 U/kg for 4 and 3 days respectively and the following two procedures were covered by rFVIIa with the initial dose of 116 µg/kg and the next doses of 87 µg/kg administered every 3 hours in procedure day and every 4 hours on the next two days. During all procedures excellent hemostasis was achieved and no hemorrhagic or thromboembolic complications were observed. Bypassing regimen therapy with aPCC and rFVIIa we applied have been shown to be safe and effective in this patient subjected to sclerotherapy procedures.
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