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Krynauw H, Omar R, Koehne J, Limbert G, Davies NH, Bezuidenhout D, Franz T. Electrospun polyester-urethane scaffold preserves mechanical properties and exhibits strain stiffening during in situ tissue ingrowth and degradation. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-2764-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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2
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Novel multimodal MRI and MicroCT imaging approach to quantify angiogenesis and 3D vascular architecture of biomaterials. Sci Rep 2019; 9:19474. [PMID: 31857617 PMCID: PMC6923434 DOI: 10.1038/s41598-019-55411-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 11/27/2019] [Indexed: 12/11/2022] Open
Abstract
Quantitative assessment of functional perfusion capacity and vessel architecture is critical when validating biomaterials for regenerative medicine purposes and requires high-tech analytical methods. Here, combining two clinically relevant imaging techniques, (magnetic resonance imaging; MRI and microcomputed tomography; MicroCT) and using the chorioallantoic membrane (CAM) assay, we present and validate a novel functional and morphological three-dimensional (3D) analysis strategy to study neovascularization in biomaterials relevant for bone regeneration. Using our new pump-assisted approach, the two scaffolds, Optimaix (laminar structure mimicking entities of the diaphysis) and DegraPol (highly porous resembling spongy bone), were shown to directly affect the architecture of the ingrowing neovasculature. Perfusion capacity (MRI) and total vessel volume (MicroCT) strongly correlated for both biomaterials, suggesting that our approach allows for a comprehensive evaluation of the vascularization pattern and efficiency of biomaterials. Being compliant with the 3R-principles (replacement, reduction and refinement), the well-established and easy-to-handle CAM model offers many advantages such as low costs, immune-incompetence and short experimental times with high-grade read-outs when compared to conventional animal models. Therefore, combined with our imaging-guided approach it represents a powerful tool to study angiogenesis in biomaterials.
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Evrova O, Houska J, Welti M, Bonavoglia E, Calcagni M, Giovanoli P, Vogel V, Buschmann J. Bioactive, Elastic, and Biodegradable Emulsion Electrospun DegraPol Tube Delivering PDGF-BB for Tendon Rupture Repair. Macromol Biosci 2016; 16:1048-63. [DOI: 10.1002/mabi.201500455] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/04/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Olivera Evrova
- Division of Plastic Surgery and Hand Surgery; University Hospital Zürich; Sternwartstrasse 14 8091 Zürich Switzerland
- Laboratory of Applied Mechanobiology; ETH Zürich; Vladimir-Prelog-Weg 1-5/10 8093 Zürich Switzerland
| | - Joanna Houska
- Division of Plastic Surgery and Hand Surgery; University Hospital Zürich; Sternwartstrasse 14 8091 Zürich Switzerland
| | - Manfred Welti
- Division of Plastic Surgery and Hand Surgery; University Hospital Zürich; Sternwartstrasse 14 8091 Zürich Switzerland
| | - Eliana Bonavoglia
- ab medica; Via J. F. Kennedy 10/12 20023 Cerro Maggiore (Milan) Italy
| | - Maurizio Calcagni
- Division of Plastic Surgery and Hand Surgery; University Hospital Zürich; Sternwartstrasse 14 8091 Zürich Switzerland
| | - Pietro Giovanoli
- Division of Plastic Surgery and Hand Surgery; University Hospital Zürich; Sternwartstrasse 14 8091 Zürich Switzerland
| | - Viola Vogel
- Laboratory of Applied Mechanobiology; ETH Zürich; Vladimir-Prelog-Weg 1-5/10 8093 Zürich Switzerland
| | - Johanna Buschmann
- Division of Plastic Surgery and Hand Surgery; University Hospital Zürich; Sternwartstrasse 14 8091 Zürich Switzerland
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Horst M, Milleret V, Noetzli S, Gobet R, Sulser T, Eberli D. Polyesterurethane and acellular matrix based hybrid biomaterial for bladder engineering. J Biomed Mater Res B Appl Biomater 2015; 105:658-667. [DOI: 10.1002/jbm.b.33591] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 11/12/2015] [Accepted: 11/18/2015] [Indexed: 01/02/2023]
Affiliation(s)
- Maya Horst
- Laboratory for Tissue Engineering and Stem Cell Therapy, Department of Urology; University Hospital Zurich; Zurich Switzerland
- Division of Pediatric Urology; University Children's Hospital; Zurich Switzerland
| | - Vincent Milleret
- Laboratory for Cell and Tissue Engineering, Department of Obstetrics; University Hospital Zurich; Zurich Switzerland
| | - Sarah Noetzli
- Laboratory for Tissue Engineering and Stem Cell Therapy, Department of Urology; University Hospital Zurich; Zurich Switzerland
| | - Rita Gobet
- Division of Pediatric Urology; University Children's Hospital; Zurich Switzerland
| | - Tullio Sulser
- Laboratory for Tissue Engineering and Stem Cell Therapy, Department of Urology; University Hospital Zurich; Zurich Switzerland
| | - Daniel Eberli
- Laboratory for Tissue Engineering and Stem Cell Therapy, Department of Urology; University Hospital Zurich; Zurich Switzerland
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Limbert G, Omar R, Krynauw H, Bezuidenhout D, Franz T. The anisotropic mechanical behaviour of electro-spun biodegradable polymer scaffolds: Experimental characterisation and constitutive formulation. J Mech Behav Biomed Mater 2015; 53:21-39. [PMID: 26301317 DOI: 10.1016/j.jmbbm.2015.07.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 07/07/2015] [Accepted: 07/16/2015] [Indexed: 01/17/2023]
Abstract
Electro-spun biodegradable polymer fibrous structures exhibit anisotropic mechanical properties dependent on the degree of fibre alignment. Degradation and mechanical anisotropy need to be captured in a constitutive formulation when computational modelling is used in the development and design optimisation of such scaffolds. Biodegradable polyester-urethane scaffolds were electro-spun and underwent uniaxial tensile testing in and transverse to the direction of predominant fibre alignment before and after in vitro degradation of up to 28 days. A microstructurally-based transversely isotropic hyperelastic continuum constitutive formulation was developed and its parameters were identified from the experimental stress-strain data of the scaffolds at various stages of degradation. During scaffold degradation, maximum stress and strain in circumferential direction decreased from 1.02 ± 0.23 MPa to 0.38 ± 0.004 MPa and from 46 ± 11 % to 12 ± 2 %, respectively. In longitudinal direction, maximum stress and strain decreased from 0.071 ± 0.016 MPa to 0.010 ± 0.007 MPa and from 69 ± 24 % to 8 ± 2 %, respectively. The constitutive parameters were identified for both directions of the non-degraded and degraded scaffold for strain range varying between 0% and 16% with coefficients of determination r(2)>0.871. The six-parameter constitutive formulation proved versatile enough to capture the varying non-linear transversely isotropic behaviour of the fibrous scaffold throughout various stages of degradation.
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Affiliation(s)
- Georges Limbert
- National Centre for Advanced Tribology at Southampton (nCATS), Engineering Sciences, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, UK; Bioengineering Science Research Group, Engineering Sciences, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, UK; Division of Biomedical Engineering, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory 7935, South Africa.
| | - Rodaina Omar
- Cardiovascular Research Unit, Chris Barnard Department of Cardiothoracic Surgery, Faculty of Health Sciences, University of Cape Town, Observatory 7935, South Africa
| | - Hugo Krynauw
- Cardiovascular Research Unit, Chris Barnard Department of Cardiothoracic Surgery, Faculty of Health Sciences, University of Cape Town, Observatory 7935, South Africa
| | - Deon Bezuidenhout
- Cardiovascular Research Unit, Chris Barnard Department of Cardiothoracic Surgery, Faculty of Health Sciences, University of Cape Town, Observatory 7935, South Africa
| | - Thomas Franz
- Division of Biomedical Engineering, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory 7935, South Africa; Centre for Research in Computational and Applied Mechanics, University of Cape Town, Rondebosch 7701, South Africa; Research Office, University of Cape Town, Mowbray 7701, South Africa
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Kivrak Pfiffner F, Waschkies C, Tian Y, Woloszyk A, Calcagni M, Giovanoli P, Rudin M, Buschmann J. A new in vivo magnetic resonance imaging method to noninvasively monitor and quantify the perfusion capacity of three-dimensional biomaterials grown on the chorioallantoic membrane of chick embryos. Tissue Eng Part C Methods 2014; 21:339-46. [PMID: 25266825 DOI: 10.1089/ten.tec.2014.0212] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Adequate vascularization in biomaterials is essential for tissue regeneration and repair. Current models do not allow easy analysis of vascularization of implants in vivo, leaving it a highly desirable goal. A tool that allows monitoring of perfusion capacity of such biomaterials noninvasively in a cheap, efficient, and reliable in vivo model would hence add great benefit to research in this field. We established, for the first time, an in vivo magnetic resonance imaging (MRI) method to quantify the perfusion capacity of a model biomaterial, DegraPol(®) foam scaffold, placed on the embryonic avian chorioallantoic membrane (CAM) in ovo. Perfusion capacity was assessed through changes in the longitudinal relaxation rate before and after injection of a paramagnetic MRI contrast agent, Gd-DOTA (Dotarem(®); Guerbet S.A.). Relaxation rate changes were compared in three different regions of the scaffold, that is, at the interface to the CAM, in the middle and on the surface of the scaffold (p<0.05). The highest relaxation rate changes, and hence perfusion capacities, were measured in the interface region where the scaffold was attached to the CAM, whereas the surface of the scaffold showed the lowest relaxation rate changes. A strong positive correlation was obtained between relaxation rate changes and histologically determined vessel density (R(2) = 0.983), which corroborates our MRI findings. As a proof-of-principle, we measured the perfusion capacity in different scaffold materials, silk fibroin either with or without human dental pulp stem cells. For these, three to four times larger perfusion capacities were obtained compared to DegraPol; demonstrating that our method is sensitive to reveal such differences. In summary, we present a novel in vivo method for analyzing the perfusion capacity in three-dimensional-biomaterials grown on the CAM, enabling the determination of the perfusion capacity of a large variety of bioengineered materials.
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Affiliation(s)
- Fatma Kivrak Pfiffner
- 1 Plastic Surgery and Hand Surgery, University Hospital Zurich , Zurich, Switzerland
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7
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Buschmann J, Puippe G, Bürgisser GM, Bonavoglia E, Giovanoli P, Calcagni M. Correspondence of high-frequency ultrasound and histomorphometry of healing rabbit Achilles tendon tissue. Connect Tissue Res 2014; 55:123-31. [PMID: 24283274 DOI: 10.3109/03008207.2013.870162] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVES Static and dynamic high-frequency ultrasound of healing rabbit Achilles tendons were set in relationship to histomorphometric analyses at three and six weeks post-surgery. MATERIALS AND METHODS Twelve New Zealand White rabbits received a clean-cut Achilles tendon laceration (the medial and lateral Musculus gastrocnemius) and were repaired with a four-strand Becker suture. Six rabbits got additionally a tight polyester urethane tube at the repair site in order to vary the adhesion extent. Tendons were analysed by static and dynamic ultrasound (control: healthy contralateral legs). The ultrasound outcome was corresponded to the tendon shape, tenocyte and tenoblast density, tenocyte and tenoblast nuclei width, collagen fibre orientation and adhesion extent. RESULTS The spindle-like morphology of healing tendons (ultrasound) was confirmed by the swollen epitenon (histology). Prediction of adhesion formation by dynamic ultrasound assessment was confirmed by histology (contact region to surrounding tissue). Hyperechogenic areas corresponded to acellular zones with aligned fibres and hypoechogenic zones to not yet oriented fibres and to cell-rich areas. CONCLUSIONS These findings add new in-depth structural knowledge to the established non-invasive analytical tool, ultrasound.
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Affiliation(s)
- Johanna Buschmann
- Department for Plastic Surgery and Hand Surgery, University Hospital Zurich , Zurich , Switzerland
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Simonet M, Stingelin N, Wismans JGF, Oomens CWJ, Driessen-Mol A, Baaijens FPT. Tailoring the void space and mechanical properties in electrospun scaffolds towards physiological ranges. J Mater Chem B 2014; 2:305-313. [DOI: 10.1039/c3tb20995d] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Milleret V, Hefti T, Hall H, Vogel V, Eberli D. Influence of the fiber diameter and surface roughness of electrospun vascular grafts on blood activation. Acta Biomater 2012; 8:4349-56. [PMID: 22842036 DOI: 10.1016/j.actbio.2012.07.032] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 07/18/2012] [Accepted: 07/20/2012] [Indexed: 01/09/2023]
Abstract
Electrospun grafts have been widely investigated for vascular graft replacement due to their ease and compatibility with many natural and synthetic polymers. Here, the effect of the processing parameters on the scaffold's architecture and subsequent reactions of partially heparinized blood triggered by contacting these topographies were studied. Degrapol® (DP) and poly(lactic-co-glycolic acid) (PLGA) electrospun fibrous scaffolds were characterized with regard to fiber diameter, pore area and scaffold roughness. The study showed that electrospinning parameters greatly affect fiber diameter together with pore dimension and overall scaffold roughness. Coagulation cascade activation, early platelet adhesion and activation were analyzed after 2h of exposure of blood to the biomaterials. While no differences were found between DP and PLGA with similar topographies, the blood reactions were observed to be dependent on the fiber diameter and scaffold roughness. Scaffolds composed of thin fibers (diameter <1μm) triggered very low coagulation and almost no platelets adhered. On the other hand, scaffolds with a bigger fiber diameter (2-3μm) triggered higher thrombin formation and more platelets adhered. The highest platelet adhesion and activations rates as well as coagulation cascade activation were found in blood incubated in contact with the scaffolds produced with the biggest fiber diameter (5μm). These findings indicate that electrospun grafts with small fiber diameter (<1μm) could perform better with reduced early thrombogenicity due to lower platelet adhesion and lower activation of platelets and coagulation cascade.
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Affiliation(s)
- Vincent Milleret
- Cells and Biomaterials, Department of Materials, ETH Zurich, Switzerland.
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Buschmann J, Calcagni M, Bürgisser GM, Bonavoglia E, Neuenschwander P, Milleret V, Giovanoli P. Synthesis, characterization and histomorphometric analysis of cellular response to a new elastic DegraPol® polymer for rabbit Achilles tendon rupture repair. J Tissue Eng Regen Med 2012; 9:584-94. [DOI: 10.1002/term.1624] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 07/04/2012] [Accepted: 08/25/2012] [Indexed: 02/05/2023]
Affiliation(s)
- Johanna Buschmann
- Division of Plastic and Reconstructive Surgery; University Hospital Zurich; Sternwartstrasse 14 8091 Zurich Switzerland
| | - Maurizio Calcagni
- Division of Plastic and Reconstructive Surgery; University Hospital Zurich; Sternwartstrasse 14 8091 Zurich Switzerland
| | - Gabriella Meier Bürgisser
- Division of Plastic and Reconstructive Surgery; University Hospital Zurich; Sternwartstrasse 14 8091 Zurich Switzerland
| | | | | | - Vincent Milleret
- Department of Materials; Cells and Biomaterials; ETH Zurich Zurich Switzerland
| | - Pietro Giovanoli
- Division of Plastic and Reconstructive Surgery; University Hospital Zurich; Sternwartstrasse 14 8091 Zurich Switzerland
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Mun CH, Jung Y, Kim SH, Lee SH, Kim HC, Kwon IK, Kim SH. Three-dimensional electrospun poly(lactide-co-ɛ-caprolactone) for small-diameter vascular grafts. Tissue Eng Part A 2012; 18:1608-16. [PMID: 22462723 DOI: 10.1089/ten.tea.2011.0695] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Nanofibers have been applied to tissue engineering scaffolds because fiber diameters are of the same scale as the physical structure of protein fibrils in the native extracellular matrix. In this study, we utilized cell matrix engineering combined with cell sheet matrix and electrospinning technologies. We studied small-diameter vascular grafts in vitro by seeding smooth muscle cells onto electrospun poly(lactide-co-ɛ-caprolactone) (PLCL) scaffolds, culturing and constructing a three-dimensional network. The vascular grafts constructed using cell matrix engineering were similar to the native vessels in their mechanical properties, such as tensile strength, tensile strain, and e-modulus. Also, they had a self-sealing property more improved than GORE-TEX because PLCL has compatible elasticity. Small-diameter vascular grafts constructed using matrix engineering have the potential to be suitable for vascular grafts.
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Affiliation(s)
- Cho Hay Mun
- Division of Life and Health Sciences, Biomaterials Research Center, Korea Institute of Science and Technology, Seoul, Korea
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12
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Buschmann J, Meier-Bürgisser G, Bonavoglia E, Neuenschwander P, Milleret V, Giovanoli P, Calcagni M. Cellular response of healing tissue to DegraPol tube implantation in rabbit Achilles tendon rupture repair: anin vivohistomorphometric study. J Tissue Eng Regen Med 2012; 7:413-20. [DOI: 10.1002/term.538] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 09/01/2011] [Accepted: 11/03/2011] [Indexed: 11/07/2022]
Affiliation(s)
- Johanna Buschmann
- Division of Plastic and Reconstructive Surgery; University Hospital Zurich; Switzerland
| | | | | | | | - Vincent Milleret
- Department of Materials, Cells and Biomaterials; ETH Zurich; Switzerland
| | - Pietro Giovanoli
- Division of Plastic and Reconstructive Surgery; University Hospital Zurich; Switzerland
| | - Maurizio Calcagni
- Division of Plastic and Reconstructive Surgery; University Hospital Zurich; Switzerland
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Krynauw H, Bruchmüller L, Bezuidenhout D, Zilla P, Franz T. Degradation-induced changes of mechanical properties of an electro-spun polyester-urethane scaffold for soft tissue regeneration. J Biomed Mater Res B Appl Biomater 2011; 99:359-68. [PMID: 21948379 DOI: 10.1002/jbm.b.31907] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 05/04/2011] [Accepted: 05/25/2011] [Indexed: 11/09/2022]
Abstract
The aim of this study was the in vitro investigation of the change in mechanical properties of a fast-degrading electro-spun polymeric scaffold for the use in soft tissue regenerative implants. Tubular scaffolds were electro-spun from a DegraPol® D30 polyesther-urethane solution (target outer diameter: 5.0 mm; scaffold wall thickness: 0.99 ± 0.18 mm). Scaffold samples were subjected to hydrolytic in vitro degradation for up to 34 days. The fiber network structure and fiber surfaces were inspected on scanning electron micrographs. Following vacuum drying and determination of mass, flat samples (9.69 ± 0.21 × 18.47 ± 2.62 mm, n = 5) underwent uni-axial tensile testing (5 load cycles, strain ε = 0 to 20%; final extension to failure) in circumferential scaffold direction after 5, 10, 14, 18, 22, 26, 30, and 34 days of degradation. Scaffold mass did not change with degradation. Maximum elastic modulus, maximum stress and associated strain were E(max) = 1.14 ± 0.23 MPa, σ(max) = 0.52 ± 0.12 MPa and ε(max) = 176.8 ± 21.9% before degradation and E(max) = 0.43 ± 0.26 MPa, σ(max) = 0.033 ± 0.028 MPa and ε(max) = 24.6 ± 3.0% after 34 days of degradation. The deterioration of mechanical properties was not reflected in the ultrastructural surface morphology of the fibers. The current exploratory study provides a basis for the development of constitutive computational models of biodegradable scaffolds with future extension of the investigation most importantly to capture mechanical effects of regenerating tissue. Future studies will include degradation in biological fluids and assessment of molecular weight for an advanced understanding of the material changes during degradation.
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Affiliation(s)
- Hugo Krynauw
- Cardiovascular Research Unit, Chris Barnard Department of Cardiothoracic Surgery, Faculty of Health Sciences, University of Cape Town, Observatory 7935, South Africa
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Sawada R, Peterson CY, Gonzalez AM, Potenza BM, Mueller B, Coimbra R, Eliceiri BP, Baird A. A phage-targeting strategy for the design of spatiotemporal drug delivery from grafted matrices. FIBROGENESIS & TISSUE REPAIR 2011; 4:7. [PMID: 21329515 PMCID: PMC3050739 DOI: 10.1186/1755-1536-4-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Accepted: 02/17/2011] [Indexed: 01/30/2023]
Abstract
Background The natural response to injury is dynamic and normally consists of complex temporal and spatial cellular changes in gene expression, which, when acting in synchrony, result in patent tissue repair and, in some instances, regeneration. However, current therapeutic regiments are static and most rely on matrices, gels and engineered skin tissue. Accordingly, there is a need to design next-generation grafting materials to enable biotherapeutic spatiotemporal targeting from clinically approved matrices. To this end, rather then focus on developing completely new grafting materials, we investigated whether phage display could be deployed onto clinically approved synthetic grafts to identify peptide motifs capable of linking pharmaceutical drugs with differential affinities and eventually, control drug delivery from matrices over both space and time. Methods To test this hypothesis, we biopanned combinatorial peptide libraries onto different formulations of a wound-healing matrix (Integra®) and eluted the bound peptides with 1) high salt, 2) collagen and glycosaminoglycan or 3) low pH. After three to six rounds of biopanning, phage recovery and phage amplification of the bound particles, any phage that had acquired a capacity to bind the matrix was sequenced. Results In this first report, we identify distinct classes of matrix-binding peptides which elute differently from the screened matrix and demonstrate that they can be applied in a spatially relevant manner. Conclusions We suggest that further applications of these combinatorial techniques to wound-healing matrices may offer a new way to improve the performance of clinically approved matrices so as to introduce temporal and spatial control over drug delivery.
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Affiliation(s)
- Ritsuko Sawada
- Department of Surgery, Division of Trauma, Surgical Critical Care and Burns, University of California San Diego School of Medicine, 200 W, Arbor Dr,, San Diego, CA 92103-8236 USA.
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Buschmann J, Welti M, Hemmi S, Neuenschwander P, Baltes C, Giovanoli P, Rudin M, Calcagni M. Three-Dimensional Co-Cultures of Osteoblasts and Endothelial Cells in DegraPol Foam: Histological and High-Field Magnetic Resonance Imaging Analyses of Pre-Engineered Capillary Networks in Bone Grafts. Tissue Eng Part A 2011; 17:291-9. [DOI: 10.1089/ten.tea.2010.0278] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Johanna Buschmann
- Division of Plastic and Reconstructive Surgery, University Hospital Zurich, ZKF, Zurich, Switzerland
| | - Manfred Welti
- Division of Plastic and Reconstructive Surgery, University Hospital Zurich, ZKF, Zurich, Switzerland
| | - Sonja Hemmi
- Division of Plastic and Reconstructive Surgery, University Hospital Zurich, ZKF, Zurich, Switzerland
| | | | - Christof Baltes
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Pietro Giovanoli
- Division of Plastic and Reconstructive Surgery, University Hospital Zurich, ZKF, Zurich, Switzerland
| | - Markus Rudin
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Maurizio Calcagni
- Division of Plastic and Reconstructive Surgery, University Hospital Zurich, ZKF, Zurich, Switzerland
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Analysis of Effective Interconnectivity of DegraPol-foams Designed for Negative Pressure Wound Therapy. MATERIALS 2009. [PMCID: PMC5445698 DOI: 10.3390/ma2010292] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Many wounds heal slowly and are difficult to manage. Therefore Negative Pressure Wound Therapy (NPWT) was developed where polymer foams are applied and a defined negative pressure removes wound fluid, reduces bacterial burden and increases the formation of granulation tissue. Although NPWT is used successfully, its mechanisms are not well understood. In particular, different NPWT dressings were never compared. Here a poly-ester urethane Degrapol® (DP)-foam was produced and compared with commercially available dressings (polyurethane-based and polyvinyl-alcohol-based) in terms of apparent pore sizes, swelling and effective interconnectivity of foam pores. DP-foams contain relatively small interconnected pores; PU-foams showed large pore size and interconnectivity; whereas PVA-foams displayed heterogeneous and poorly interconnected pores. PVA-foams swelled by 40 %, whereas DP- and PU-foams remained almost without swelling. Effective interconnectivity was investigated by submitting fluorescent beads of 3, 20 and 45 μm diameter through the foams. DP- and PU-foams removed 70-90 % of all beads within 4 h, independent of the bead diameter or bead pre-adsorption with serum albumin. For PVA-foams albumin pre-adsorbed beads circulated longer, where 20 % of 3 μm and 10 % of 20 μm diameter beads circulated after 96 h. The studies indicate that efficient bead perfusion does not only depend on pore size and swelling capacity, but effective interconnectivity might also depend on chemical composition of the foam itself. In addition due to the efficient sieve-effect of the foams uptake of wound components in vivo might occur only for short time suggesting other mechanisms being decisive for success of NPWT.
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