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Schwager JM, Di Maggio N, Grosso A, Rasadurai A, Minder N, Hubbell JA, Kappos EA, Schaefer DJ, Briquez PS, Banfi A, Burger MG. Semaphorin 3A promotes the long-term persistence of human SVF-derived microvascular networks in engineered grafts. Front Bioeng Biotechnol 2024; 12:1396450. [PMID: 39234267 PMCID: PMC11371724 DOI: 10.3389/fbioe.2024.1396450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 08/07/2024] [Indexed: 09/06/2024] Open
Abstract
Introduction The stromal vascular fraction (SVF) of human adipose tissue is an attractive cell source for engineering grafts with intrinsic vascularization potential, as it is rich in vasculogenic progenitors. However, in order to maintain their functional perfusion it is important to promote the in vivo stabilization of newly assembled microvascular networks. We previously found that Semaphorin 3A (Sema3A) promotes the rapid stabilization of new blood vessels induced by VEGF overexpression in skeletal muscle. Here we investigated whether Sema3A could promote the assembly, connection to circulation and persistence of human SVF-derived microvascular networks in engineered grafts. Methods Recombinant Sema3A was engineered with a transglutaminase substrate sequence (TG-Sema3A) to allow cross-linking into fibrin hydrogels. Grafts were prepared with freshly isolated human SVF cells in fibrin hydrogels decorated with 0, 0.1 or 100 μg/ml TG-Sema3A and implanted subcutaneously in immune-deficient mice. Results After 1 week in vivo, the assembly of human-derived networks was similar in all conditions. The outer part of the grafts was populated by blood vessels of both human and mouse origin, which formed abundant hybrid structures within a common basal lamina. About 90% of human-derived blood vessels were functionally connected to the host circulation in all conditions. However, in the control samples human vessels were unstable. In fact, they significantly regressed by 6 weeks and could no longer be found by 12 weeks. In contrast, a low Sema3A dose (0.1 μg/ml) promoted further human vascular expansion by about 2-fold at 6 weeks and protected them from regression until 12 weeks. From a mechanistic point of view, the stabilization of SVF-derived vessels by 0.1 μg/ml of Sema3A correlated with the recruitment of a specific population of monocytes expressing its receptor Neuropilin-1. Discussion In conclusion, Sema3A is a potent stimulator of in vivo long-term persistence of microvascular networks derived from human SVF. Therefore, decoration of matrices with Sema3a can be envisioned to promote the functional support of tissue engineered grafts.
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Affiliation(s)
- Juan M Schwager
- Regenerative Angiogenesis Laboratory, Department of Biomedicine, Basel University Hospital and University of Basel, Basel, Switzerland
- Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, Basel University Hospital, Basel, Switzerland
| | - Nunzia Di Maggio
- Regenerative Angiogenesis Laboratory, Department of Biomedicine, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Andrea Grosso
- Regenerative Angiogenesis Laboratory, Department of Biomedicine, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Abeelan Rasadurai
- Regenerative Angiogenesis Laboratory, Department of Biomedicine, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Nadja Minder
- Regenerative Angiogenesis Laboratory, Department of Biomedicine, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Jeffrey A Hubbell
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, United States
| | - Elisabeth A Kappos
- Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, Basel University Hospital, Basel, Switzerland
- Department of Clinical Research, Medical Faculty, University of Basel, Basel, Switzerland
| | - Dirk J Schaefer
- Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, Basel University Hospital, Basel, Switzerland
| | - Priscilla S Briquez
- Department of General and Visceral Surgery, Medical Center-University of Freiburg, Freiburg, Germany
| | - Andrea Banfi
- Regenerative Angiogenesis Laboratory, Department of Biomedicine, Basel University Hospital and University of Basel, Basel, Switzerland
- Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, Basel University Hospital, Basel, Switzerland
| | - Maximilian G Burger
- Regenerative Angiogenesis Laboratory, Department of Biomedicine, Basel University Hospital and University of Basel, Basel, Switzerland
- Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, Basel University Hospital, Basel, Switzerland
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2
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Burger MG, Grosso A, Briquez PS, Born GME, Lunger A, Schrenk F, Todorov A, Sacchi V, Hubbell JA, Schaefer DJ, Banfi A, Di Maggio N. Robust coupling of angiogenesis and osteogenesis by VEGF-decorated matrices for bone regeneration. Acta Biomater 2022; 149:111-125. [PMID: 35835287 DOI: 10.1016/j.actbio.2022.07.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 06/13/2022] [Accepted: 07/06/2022] [Indexed: 12/11/2022]
Abstract
Rapid vascularization of clinical-size bone grafts is an unsolved challenge in regenerative medicine. Vascular endothelial growth factor-A (VEGF) is the master regulator of angiogenesis. Its over-expression by genetically modified human osteoprogenitors has been previously evaluated to drive vascularization in osteogenic grafts, but has been observed to cause paradoxical bone loss through excessive osteoclast recruitment. However, during bone development angiogenesis and osteogenesis are physiologically coupled by VEGF expression. Here we investigated whether the mode of VEGF delivery may be a key to recapitulate its physiological function. VEGF activity requires binding to the extracellular matrix, and heterogeneous levels of expression lead to localized microenvironments of excessive dose. Therefore we hypothesized that a homogeneous distribution of matrix-associated factor in the microenvironment may enable efficient coupling of angiogenesis and bone formation. This was achieved by decorating fibrin matrices with a cross-linkable engineered version of VEGF (TG-VEGF) that is released only by enzymatic cleavage by invading cells. In ectopic grafts, both TG-VEGF and VEGF-expressing progenitors similarly improved vascularization within the first week, but efficient bone formation was possible only in the factor-decorated matrices, whereas heterogenous, cell-based VEGF expression caused significant bone loss. In critical-size orthotopic calvaria defects, TG-VEGF effectively improved early vascular invasion, osteoprogenitor survival and differentiation, as well as bone repair compared to both controls and VEGF-expressing progenitors. In conclusion, homogenous distribution of matrix-associated VEGF protein preserves the physiological coupling of angiogenesis and osteogenesis, providing an attractive and clinically applicable strategy to engineer vascularized bone. STATEMENT OF SIGNIFICANCE: The therapeutic regeneration of vascularized bone is an unsolved challenge in regenerative medicine. Stimulation of blood vessel growth by over-expression of VEGF has been associated with paradoxical bone loss, whereas angiogenesis and osteogenesis are physiologically coupled by VEGF during development. Here we found that controlling the distribution of VEGF dose in an osteogenic graft is key to recapitulate its physiological function. In fact, homogeneous decoration of fibrin matrices with engineered VEGF could improve both vascularization and bone formation in orthotopic critical-size defects, dispensing with the need for combined osteogenic factor delivery. VEGF-decorated fibrin matrices provide a readily translatable platform for engineering a controlled microenvironment for bone regeneration.
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Affiliation(s)
- Maximilian G Burger
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, 4031, Basel, Switzerland; Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, Basel University Hospital, Petersgraben 4, 4031, Basel, Switzerland
| | - Andrea Grosso
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, 4031, Basel, Switzerland
| | - Priscilla S Briquez
- Pritzker School of Molecular Engineering, University of Chicago, 5640 S Ellis Ave, Chicago, IL 60637, USA
| | - Gordian M E Born
- Tissue Engineering, Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, 4031, Basel, Switzerland
| | - Alexander Lunger
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, 4031, Basel, Switzerland; Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, Basel University Hospital, Petersgraben 4, 4031, Basel, Switzerland
| | - Flavio Schrenk
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, 4031, Basel, Switzerland
| | - Atanas Todorov
- Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, Basel University Hospital, Petersgraben 4, 4031, Basel, Switzerland; Tissue Engineering, Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, 4031, Basel, Switzerland
| | - Veronica Sacchi
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, 4031, Basel, Switzerland
| | - Jeffrey A Hubbell
- Pritzker School of Molecular Engineering, University of Chicago, 5640 S Ellis Ave, Chicago, IL 60637, USA
| | - Dirk J Schaefer
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, 4031, Basel, Switzerland; Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, Basel University Hospital, Petersgraben 4, 4031, Basel, Switzerland
| | - Andrea Banfi
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, 4031, Basel, Switzerland; Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, Basel University Hospital, Petersgraben 4, 4031, Basel, Switzerland.
| | - Nunzia Di Maggio
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, 4031, Basel, Switzerland.
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Cross-sectional Vascularization Pattern of the Adipofascial Anterolateral Thigh Flap for Application in Tissue-engineered Bone Grafts. PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN 2022; 10:e4136. [PMID: 35223345 PMCID: PMC8865508 DOI: 10.1097/gox.0000000000004136] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 12/14/2021] [Indexed: 11/26/2022]
Abstract
As part of the engineering of bone grafts, wrapping constructs in well-vascularized tissue, such as fascial flaps, improves bone formation. Our aim was to understand the cross-sectional vascularization pattern of human adipofascial flaps for this application. METHODS Seven adipofascial anterolateral thigh (ALT) flaps were harvested from five human cadaveric specimens. Axial vessel density was analyzed by immunohistochemistry and quantitative histology. RESULTS We found a high density of blood vessels directly superficial to and close to the fascia. A secondary plexus in between this first suprafascial plexus and the subdermal plexus was also identified. In all specimens, this second plexus showed less vascular density, and appeared to be at a constant level within the suprafascial fat throughout the flaps. The peak measurements for this secondary plexus varied between 1.2 and 2 mm above the deep fascia, depending on the donor's body mass index. CONCLUSIONS Quantitative immunohistochemistry is a reliable method to quantify and locate vessel density in an adipofascial flap. This is vital information before wrapping nonvascularized material into such a flap to estimate the inosculation potential of these vessels and likelihood of survival of the tissue. To profit from both suprafascial vascular plexuses, a correlation between subcutaneous tissue thickness and distance of the second plexus to the fascia should be further investigated. For the moment, we recommend maintaining at least 2-3 mm of subcutaneous fatty tissue on the fascia, to profit from both plexuses. Engineered constructs should be wrapped on the superficial medial side of the fascial flap to enhance vascularization.
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Redenski I, Guo S, Machour M, Szklanny A, Landau S, Egozi D, Gabet Y, Levenberg S. Microcomputed Tomography-Based Analysis of Neovascularization within Bioengineered Vascularized Tissues. ACS Biomater Sci Eng 2022; 8:232-241. [PMID: 34905338 DOI: 10.1021/acsbiomaterials.1c01401] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In the field of tissue engineering, evaluating newly formed vascular networks is considered a fundamental step in deciphering the processes underlying tissue development. Several common modalities exist to study vessel network formation and function. However, a proper methodology that allows through three-dimensional visualization of neovessels in a reproducible manner is required. Here, we describe in-depth exploration, visualization, and analysis of vessels within newly formed tissues by utilizing a contrast agent perfusion protocol and high-resolution microcomputed tomography. Bioengineered constructs consisting of porous, biocompatible, and biodegradable scaffolds are loaded with cocultures of adipose-derived microvascular endothelial cells (HAMECs) and dental pulp stem cells (DPSCs) and implanted in a rat femoral bundle model. After 14 days of in vivo maturation, we performed the optimized perfusion protocol to allow host penetrating vascular visualization and assessment within neotissues. Following high-resolution microCT scanning of DPSC:HAMEC explants, we performed the volumetric and spatial analysis of neovasculature. Eventually, the process was repeated with a previously published coculture system for prevascularization based on adipose-derived mesenchymal stromal cells (MSCs) and HAMECs. Overall, our approach allows a comprehensive understanding of vessel organization during engraftment and development of neotissues.
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Affiliation(s)
- Idan Redenski
- Department of Biomedical Engineering, Technion─Israel Institute of Technology, Haifa 3200003, Israel
| | - Shaowei Guo
- Department of Biomedical Engineering, Technion─Israel Institute of Technology, Haifa 3200003, Israel
- The First Affiliated Hospital, Shantou University Medical College, Shantou 515000, China
| | - Majd Machour
- Department of Biomedical Engineering, Technion─Israel Institute of Technology, Haifa 3200003, Israel
| | - Ariel Szklanny
- Department of Biomedical Engineering, Technion─Israel Institute of Technology, Haifa 3200003, Israel
| | - Shira Landau
- Department of Biomedical Engineering, Technion─Israel Institute of Technology, Haifa 3200003, Israel
| | - Dana Egozi
- Department of Plastic and Reconstructive Surgery, Kaplan Hospital, Rehovot and the Hebrew University, Jerusalem 9190401, Israel
| | - Yankel Gabet
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv 6997801, Israel
| | - Shulamit Levenberg
- Department of Biomedical Engineering, Technion─Israel Institute of Technology, Haifa 3200003, Israel
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5
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Khalil TH, Zoabi A, Falah M, Nseir N, David DB, Laevsky I, Zussman E, Ronen O, Redenski I, Srouji S. Micro-Osteo Tubular Scaffolds: a Method for Induction of Bone Tissue Constructs. REGENERATIVE ENGINEERING AND TRANSLATIONAL MEDICINE 2021. [DOI: 10.1007/s40883-021-00236-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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6
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Redenski I, Guo S, Machour M, Szklanny A, Landau S, Kaplan B, Lock RI, Gabet Y, Egozi D, Vunjak‐Novakovic G, Levenberg S. Engineered Vascularized Flaps, Composed of Polymeric Soft Tissue and Live Bone, Repair Complex Tibial Defects. ADVANCED FUNCTIONAL MATERIALS 2021; 31:2008687. [DOI: 10.1002/adfm.202008687] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Indexed: 02/05/2023]
Affiliation(s)
- Idan Redenski
- Department of Biomedical Engineering Technion—Israel Institute of Technology Haifa 32000 Israel
| | - Shaowei Guo
- Department of Biomedical Engineering Technion—Israel Institute of Technology Haifa 32000 Israel
- The First Affiliated Hospital Shantou University Medical College Shantou 515000 China
| | - Majd Machour
- Department of Biomedical Engineering Technion—Israel Institute of Technology Haifa 32000 Israel
| | - Ariel Szklanny
- Department of Biomedical Engineering Technion—Israel Institute of Technology Haifa 32000 Israel
| | - Shira Landau
- Department of Biomedical Engineering Technion—Israel Institute of Technology Haifa 32000 Israel
| | - Ben Kaplan
- Department of Biomedical Engineering Technion—Israel Institute of Technology Haifa 32000 Israel
| | - Roberta I. Lock
- Department of Biomedical Engineering Columbia University New York NY 10032 USA
| | - Yankel Gabet
- Department of Anatomy and Anthropology Sackler Faculty of Medicine Tel‐Aviv University Tel‐Aviv 6997801 Israel
| | - Dana Egozi
- Department of Plastic and Reconstructive Surgery Kaplan Hospital Rehovot and the Hebrew University Jerusalem 7661041 Israel
| | | | - Shulamit Levenberg
- Department of Biomedical Engineering Technion—Israel Institute of Technology Haifa 32000 Israel
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7
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Vascularization Strategies in Bone Tissue Engineering. Cells 2021; 10:cells10071749. [PMID: 34359919 PMCID: PMC8306064 DOI: 10.3390/cells10071749] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/05/2021] [Accepted: 07/06/2021] [Indexed: 12/12/2022] Open
Abstract
Bone is a highly vascularized tissue, and its development, maturation, remodeling, and regeneration are dependent on a tight regulation of blood vessel supply. This condition also has to be taken into consideration in the context of the development of artificial tissue substitutes. In classic tissue engineering, bone-forming cells such as primary osteoblasts or mesenchymal stem cells are introduced into suitable scaffolds and implanted in order to treat critical-size bone defects. However, such tissue substitutes are initially avascular. Because of the occurrence of hypoxic conditions, especially in larger tissue substitutes, this leads to the death of the implanted cells. Therefore, it is necessary to devise vascularization strategies aiming at fast and efficient vascularization of implanted artificial tissues. In this review article, we present and discuss the current vascularization strategies in bone tissue engineering. These are based on the use of angiogenic growth factors, the co-implantation of blood vessel forming cells, the ex vivo microfabrication of blood vessels by means of bioprinting, and surgical methods for creating surgically transferable composite tissues.
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8
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Largo RD, Burger MG, Harschnitz O, Waschkies CF, Grosso A, Scotti C, Kaempfen A, Gueven S, Jundt G, Scherberich A, Schaefer DJ, Banfi A, Di Maggio N. VEGF Over-Expression by Engineered BMSC Accelerates Functional Perfusion, Improving Tissue Density and In-Growth in Clinical-Size Osteogenic Grafts. Front Bioeng Biotechnol 2020; 8:755. [PMID: 32714920 PMCID: PMC7351518 DOI: 10.3389/fbioe.2020.00755] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 06/12/2020] [Indexed: 11/14/2022] Open
Abstract
The first choice for reconstruction of clinical-size bone defects consists of autologous bone flaps, which often lack the required mechanical strength and cause significant donor-site morbidity. We have previously developed biological substitutes in a rabbit model by combining bone tissue engineering and flap pre-fabrication. However, spontaneous vascularization was insufficient to ensure progenitor survival in the core of the constructs. Here, we hypothesized that increased angiogenic stimulation within constructs by exogenous VEGF can significantly accelerate early vascularization and tissue in-growth. Bone marrow stromal cells from NZW rabbits (rBMSC) were transduced with a retroviral vector to express rabbit VEGF linked to a truncated version of rabbit CD4 as a cell-surface marker. Autologous cells were seeded in clinical-size 5.5 cm3 HA scaffolds wrapped in a panniculus carnosus flap to provide an ample vascular supply, and implanted ectopically. Constructs seeded with VEGF-expressing rBMSC showed significantly increased progenitor survivival, depth of tissue ingrowth and amount of mineralized tissue. Contrast-enhanced MRI after 1 week in vivo showed significantly improved tissue perfusion in the inner layer of the grafts compared to controls. Interestingly, grafts containing VEGF-expressing rBMSC displayed a hierarchically organized functional vascular tree, composed of dense capillary networks in the inner layers connected to large-caliber feeding vessels entering the constructs at the periphery. These data constitute proof of principle that providing sustained VEGF signaling, independently of cells experiencing hypoxia, is effective to drive rapid vascularization and increase early perfusion in clinical-size osteogenic grafts, leading to improved tissue formation deeper in the constructs.
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Affiliation(s)
- Rene' D Largo
- Cell and Gene Therapy, Department of Biomedicine, >Basel University Hospital and University of Basel, Basel, Switzerland.,Plastic and Reconstructive Surgery, Department of Surgery, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Maximilian G Burger
- Cell and Gene Therapy, Department of Biomedicine, >Basel University Hospital and University of Basel, Basel, Switzerland.,Plastic and Reconstructive Surgery, Department of Surgery, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Oliver Harschnitz
- Cell and Gene Therapy, Department of Biomedicine, >Basel University Hospital and University of Basel, Basel, Switzerland.,Plastic and Reconstructive Surgery, Department of Surgery, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Conny F Waschkies
- Institute for Biomedical Engineering, ETH and University of Zurich, Zurich, Switzerland.,Department of Surgical Research, University Hospital Zurich, Zurich, Switzerland
| | - Andrea Grosso
- Cell and Gene Therapy, Department of Biomedicine, >Basel University Hospital and University of Basel, Basel, Switzerland.,Plastic and Reconstructive Surgery, Department of Surgery, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Celeste Scotti
- Tissue Engineering, Department of Biomedicine, University Hospital of Basel, University of Basel, Basel, Switzerland
| | - Alexandre Kaempfen
- Plastic and Reconstructive Surgery, Department of Surgery, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Sinan Gueven
- Tissue Engineering, Department of Biomedicine, University Hospital of Basel, University of Basel, Basel, Switzerland
| | - Gernot Jundt
- Institute of Pathology, University Hospital of Basel, Basel, Switzerland
| | - Arnaud Scherberich
- Tissue Engineering, Department of Biomedicine, University Hospital of Basel, University of Basel, Basel, Switzerland
| | - Dirk J Schaefer
- Plastic and Reconstructive Surgery, Department of Surgery, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Andrea Banfi
- Cell and Gene Therapy, Department of Biomedicine, >Basel University Hospital and University of Basel, Basel, Switzerland.,Plastic and Reconstructive Surgery, Department of Surgery, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Nunzia Di Maggio
- Cell and Gene Therapy, Department of Biomedicine, >Basel University Hospital and University of Basel, Basel, Switzerland
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9
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Gianni-Barrera R, Di Maggio N, Melly L, Burger MG, Mujagic E, Gürke L, Schaefer DJ, Banfi A. Therapeutic vascularization in regenerative medicine. Stem Cells Transl Med 2020; 9:433-444. [PMID: 31922362 PMCID: PMC7103618 DOI: 10.1002/sctm.19-0319] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/12/2019] [Indexed: 02/06/2023] Open
Abstract
Therapeutic angiogenesis, that is, the generation of new vessels by delivery of specific factors, is required both for rapid vascularization of tissue‐engineered constructs and to treat ischemic conditions. Vascular endothelial growth factor (VEGF) is the master regulator of angiogenesis. However, uncontrolled expression can lead to aberrant vascular growth and vascular tumors (angiomas). Major challenges to fully exploit VEGF potency for therapy include the need to precisely control in vivo distribution of growth factor dose and duration of expression. In fact, the therapeutic window of VEGF delivery depends on its amount in the microenvironment around each producing cell rather than on the total dose, since VEGF remains tightly bound to extracellular matrix (ECM). On the other hand, short‐term expression of less than about 4 weeks leads to unstable vessels, which promptly regress following cessation of the angiogenic stimulus. Here, we will briefly overview some key aspects of the biology of VEGF and angiogenesis and discuss their therapeutic implications with a particular focus on approaches using gene therapy, genetically modified progenitors, and ECM engineering with recombinant factors. Lastly, we will present recent insights into the mechanisms that regulate vessel stabilization and the switch between normal and aberrant vascular growth after VEGF delivery, to identify novel molecular targets that may improve both safety and efficacy of therapeutic angiogenesis.
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Affiliation(s)
- Roberto Gianni-Barrera
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Nunzia Di Maggio
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Ludovic Melly
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Basel, Switzerland.,Cardiac, Vascular, and Thoracic Surgery, CHU UCL Namur, Yvoir, Belgium
| | - Maximilian G Burger
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Basel, Switzerland.,Plastic and Reconstructive Surgery, Department of Surgery, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Edin Mujagic
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Basel, Switzerland.,Vascular Surgery, Department of Surgery, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Lorenz Gürke
- Vascular Surgery, Department of Surgery, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Dirk J Schaefer
- Plastic and Reconstructive Surgery, Department of Surgery, Basel University Hospital and University of Basel, Basel, Switzerland
| | - Andrea Banfi
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital and University of Basel, Basel, Switzerland.,Plastic and Reconstructive Surgery, Department of Surgery, Basel University Hospital and University of Basel, Basel, Switzerland.,Vascular Surgery, Department of Surgery, Basel University Hospital and University of Basel, Basel, Switzerland
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10
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Yusof MFH, Zahari W, Hashim SNM, Osman ZF, Chandra H, Kannan TP, Noordin KBAA, Azlina A. Angiogenic and osteogenic potentials of dental stem cells in bone tissue engineering. J Oral Biol Craniofac Res 2018; 8:48-53. [PMID: 29556464 PMCID: PMC5854554 DOI: 10.1016/j.jobcr.2017.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 10/18/2017] [Indexed: 02/07/2023] Open
Abstract
Manipulation of dental stem cells (DSCs) using current technologies in tissue engineering unveil promising prospect in regenerative medicine. DSCs have shown to possess angiogenic and osteogenic potential in both in vivo and in vitro. Neural crest derived DSCs can successfully be isolated from various dental tissues, exploiting their intrinsic great differentiation potential. In this article, researcher team intent to review the characteristics of DSCs, with focus on their angiogenic and osteogenic differentiation lineage. Clinical data on DSCs are still lacking to prove their restorative abilities despite extensive contemporary literature, warranting research to further validate their application for bone tissue engineering.
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Affiliation(s)
- Muhammad Fuad Hilmi Yusof
- Basic Sciences and Oral Biology Unit, School of Dental Sciences, USM Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Wafa’ Zahari
- Basic Sciences and Oral Biology Unit, School of Dental Sciences, USM Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Siti Nurnasihah Md Hashim
- Basic Sciences and Oral Biology Unit, School of Dental Sciences, USM Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Zul Faizuddin Osman
- Basic Sciences and Oral Biology Unit, School of Dental Sciences, USM Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Hamshawagini Chandra
- Basic Sciences and Oral Biology Unit, School of Dental Sciences, USM Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Thirumulu Ponnuraj Kannan
- Basic Sciences and Oral Biology Unit, School of Dental Sciences, USM Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
- Human Genome Center, School of Medical Sciences, USM Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | | | - Ahmad Azlina
- Basic Sciences and Oral Biology Unit, School of Dental Sciences, USM Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
- Human Genome Center, School of Medical Sciences, USM Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
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11
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Freeman FE, McNamara LM. Endochondral Priming: A Developmental Engineering Strategy for Bone Tissue Regeneration. TISSUE ENGINEERING PART B-REVIEWS 2016; 23:128-141. [PMID: 27758156 DOI: 10.1089/ten.teb.2016.0197] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Tissue engineering and regenerative medicine have significant potential to treat bone pathologies by exploiting the capacity for bone progenitors to grow and produce tissue constituents under specific biochemical and physical conditions. However, conventional tissue engineering approaches, which combine stem cells with biomaterial scaffolds, are limited as the constructs often degrade, due to a lack of vascularization, and lack the mechanical integrity to fulfill load bearing functions, and as such are not yet widely used for clinical treatment of large bone defects. Recent studies have proposed that in vitro tissue engineering approaches should strive to simulate in vivo bone developmental processes and, thereby, imitate natural factors governing cell differentiation and matrix production, following the paradigm recently defined as "developmental engineering." Although developmental engineering strategies have been recently developed that mimic specific aspects of the endochondral ossification bone formation process, these findings are not widely understood. Moreover, a critical comparison of these approaches to standard biomaterial-based bone tissue engineering has not yet been undertaken. For that reason, this article presents noteworthy experimental findings from researchers focusing on developing an endochondral-based developmental engineering strategy for bone tissue regeneration. These studies have established that in vitro approaches, which mimic certain aspects of the endochondral ossification process, namely the formation of the cartilage template and the vascularization of the cartilage template, can promote mineralization and vascularization to a certain extent both in vitro and in vivo. Finally, this article outlines specific experimental challenges that must be overcome to further exploit the biology of endochondral ossification and provide a tissue engineering construct for clinical treatment of large bone/nonunion defects and obviate the need for bone tissue graft.
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Affiliation(s)
- Fiona E Freeman
- Centre for Biomechanics Research (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway , Galway, Ireland
| | - Laoise M McNamara
- Centre for Biomechanics Research (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway , Galway, Ireland
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Stiers PJ, van Gastel N, Carmeliet G. Targeting the hypoxic response in bone tissue engineering: A balance between supply and consumption to improve bone regeneration. Mol Cell Endocrinol 2016; 432:96-105. [PMID: 26768117 DOI: 10.1016/j.mce.2015.12.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 12/22/2015] [Accepted: 12/31/2015] [Indexed: 12/19/2022]
Abstract
Bone tissue engineering is a promising therapeutic alternative for bone grafting of large skeletal defects. It generally comprises an ex vivo engineered combination of a carrier structure, stem/progenitor cells and growth factors. However, the success of these regenerative implants largely depends on how well implanted cells will adapt to the hostile and hypoxic host environment they encounter after implantation. In this review, we will discuss how hypoxia signalling may be used to improve bone regeneration in a tissue-engineered construct. First, hypoxia signalling induces angiogenesis which increases the survival of the implanted cells as well as stimulates bone formation. Second, hypoxia signalling has also angiogenesis-independent effects on mesenchymal cells in vitro, offering exciting new possibilities to improve tissue-engineered bone regeneration in vivo. In addition, studies in other fields have shown that benefits of modulating hypoxia signalling include enhanced cell survival, proliferation and differentiation, culminating in a more potent regenerative implant. Finally, the stimulation of endochondral bone formation as a physiological pathway to circumvent the harmful effects of hypoxia will be briefly touched upon. Thus, angiogenic dependent and independent processes may counteract the deleterious hypoxic effects and we will discuss several therapeutic strategies that may be combined to withstand the hypoxia upon implantation and improve bone regeneration.
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Affiliation(s)
- Pieter-Jan Stiers
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Prometheus, Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium
| | - Nick van Gastel
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Prometheus, Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium
| | - Geert Carmeliet
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Prometheus, Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium.
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Engraftment of Prevascularized, Tissue Engineered Constructs in a Novel Rabbit Segmental Bone Defect Model. Int J Mol Sci 2015; 16:12616-30. [PMID: 26053395 PMCID: PMC4490464 DOI: 10.3390/ijms160612616] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Revised: 04/20/2015] [Accepted: 05/26/2015] [Indexed: 12/26/2022] Open
Abstract
The gold standard treatment of large segmental bone defects is autologous bone transfer, which suffers from low availability and additional morbidity. Tissue engineered bone able to engraft orthotopically and a suitable animal model for pre-clinical testing are direly needed. This study aimed to evaluate engraftment of tissue-engineered bone with different prevascularization strategies in a novel segmental defect model in the rabbit humerus. Decellularized bone matrix (Tutobone) seeded with bone marrow mesenchymal stromal cells was used directly orthotopically or combined with a vessel and inserted immediately (1-step) or only after six weeks of subcutaneous “incubation” (2-step). After 12 weeks, histological and radiological assessment was performed. Variable callus formation was observed. No bone formation or remodeling of the graft through TRAP positive osteoclasts could be detected. Instead, a variable amount of necrotic tissue formed. Although necrotic area correlated significantly with amount of vessels and the 2-step strategy had significantly more vessels than the 1-step strategy, no significant reduction of necrotic area was found. In conclusion, the animal model developed here represents a highly challenging situation, for which a suitable engineered bone graft with better prevascularization, better resorbability and higher osteogenicity has yet to be developed.
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Weigand A, Beier JP, Hess A, Gerber T, Arkudas A, Horch RE, Boos AM. Acceleration of vascularized bone tissue-engineered constructs in a large animal model combining intrinsic and extrinsic vascularization. Tissue Eng Part A 2015; 21:1680-94. [PMID: 25760576 DOI: 10.1089/ten.tea.2014.0568] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
During the last decades, a range of excellent and promising strategies in Bone Tissue Engineering have been developed. However, the remaining major problem is the lack of vascularization. In this study, extrinsic and intrinsic vascularization strategies were combined for acceleration of vascularization. For optimal biomechanical stability of the defect site and simplifying future transition into clinical application, a primary stable and approved nanostructured bone substitute in clinically relevant size was used. An arteriovenous (AV) loop was microsurgically created in sheep and implanted, together with the bone substitute, in either perforated titanium chambers (intrinsic/extrinsic) for different time intervals of up to 18 weeks or isolated Teflon(®) chambers (intrinsic) for 18 weeks. Over time, magnetic resonance imaging and micro-computed tomography (CT) analyses illustrate the dense vascularization arising from the AV loop. The bone substitute was completely interspersed with newly formed tissue after 12 weeks of intrinsic/extrinsic vascularization and after 18 weeks of intrinsic/extrinsic and intrinsic vascularization. Successful matrix change from an inorganic to an organic scaffold could be demonstrated in vascularized areas with scanning electron microscopy and energy dispersive X-ray spectroscopy. Using the intrinsic vascularization method only, the degradation of the scaffold and osteoclastic activity was significantly lower after 18 weeks, compared with 12 and 18 weeks in the combined intrinsic-extrinsic model. Immunohistochemical staining revealed an increase in bone tissue formation over time, without a difference between intrinsic/extrinsic and intrinsic vascularization after 18 weeks. This study presents the combination of extrinsic and intrinsic vascularization strategies for the generation of an axially vascularized bone substitute in clinically relevant size using a large animal model. The additional extrinsic vascularization promotes tissue ingrowth and remodeling processes of the bone substitute. Extrinsic vessels contribute to faster vascularization and finally anastomose with intrinsic vasculature, allowing microvascular transplantation of the bone substitute after a shorter prevascularization time than using the intrinsic method only. It can be reasonably assumed that the usage of perforated chambers can significantly reduce the time until transplantation of bone constructs. Finally, this study paves the way for further preclinical testing for proof of the concept as a basis for early clinical applicability.
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Affiliation(s)
- Annika Weigand
- 1 Department of Plastic and Hand Surgery, University Hospital of Erlangen , Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
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Boccaccini AR, Kneser U, Arkudas A. Scaffolds for vascularized bone regeneration: advances and challenges. Expert Rev Med Devices 2014; 9:457-60. [DOI: 10.1586/erd.12.49] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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16
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2D motion analysis of rabbits after Achilles tendon rupture repair and histological analysis of extracted tendons: can the number of animals be reduced by operating both hind legs simultaneously? Injury 2013; 44:1302-8. [PMID: 23827396 DOI: 10.1016/j.injury.2013.05.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 04/17/2013] [Accepted: 05/22/2013] [Indexed: 02/02/2023]
Abstract
BACKGROUND Considering the 3Rs principle in animal experiments, there is a demand to perform research experiments with the fewest number of animals possible while warranting the welfare of the animals. Orthopaedic experimental studies involving operations on the hind legs of rabbits are either performed on one hind leg with the second hind leg serving as control or on both hind legs simultaneously (control: rabbits with no operations at all). METHODS The Achilles tendon of rabbits was transected and sutured, and the two-dimensional motion pattern of animals having only one leg operated was compared to rabbits having both hind legs operated (control: non-treated animals). Step length, maximum ankle angle, minimum ankle angle and the resulting range of motion of both hind legs were determined weekly over a time span from 3 weeks to 12 weeks post-operation. The results were fitted by a linear mixed effects model including time dependency. Moreover, all tendon specimen were analysed histologically. Tenocyte and tenoblast density, tenocyte and tenoblast nuclei width, inflammation level and collagen fibre alignment were determined. RESULTS Statistically significant differences in the motion pattern were found when one-leg treated and two-leg treated animals were compared. However, the absolute differences were on average less than 20%. Histologically, 1-leg treated animals had tendon tissue with higher cell density, but lower inflammation and less ondulated collagen fibres compared to 2-leg treated animals; the nuclei width was the same for both groups. With regard to welfare, all animals were fine during the experiments. CONCLUSIONS While comparative studies should be performed with one-leg treated animals due to interaction effects, for proof-of-principle studies, operating two legs per animal may be justified as the welfare of the animals is warranted. This is a great benefit in the sense of the 3Rs because up to 50% of animals can be spared.
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Osteogenic graft vascularization and bone resorption by VEGF-expressing human mesenchymal progenitors. Biomaterials 2013; 34:5025-35. [PMID: 23566801 DOI: 10.1016/j.biomaterials.2013.03.040] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 03/14/2013] [Indexed: 02/07/2023]
Abstract
Rapid vascularisation of tissue-engineered osteogenic grafts is a major obstacle in the development of regenerative medicine approaches for bone repair. Vascular endothelial growth factor (VEGF) is the master regulator of vascular growth. We investigated a cell-based gene therapy approach to generate osteogenic grafts with an increased vascularization potential in an ectopic nude rat model in vivo, by genetically modifying human bone marrow-derived stromal/stem cells (BMSC) to express rat VEGF. BMSC were loaded onto silicate-substituted apatite granules, which are a clinically established osteo-conductive material. Eight weeks after implantation, the vascular density of constructs seeded with VEGF-BMSC was 3-fold greater than with control cells, consisting of physiologically structured vascular networks with both conductance vessels and capillaries. However, VEGF specifically caused a global reduction in bone quantity, which consisted of thin trabeculae of immature matrix. VEGF did not impair BMSC engraftment in vivo, but strongly increased the recruitment of TRAP- and Cathepsin K-positive osteoclasts. These data suggest that VEGF over-expression is effective to improve the vascularization of osteogenic grafts, but also has the potential to disrupt bone homoeostasis towards excessive degradation, posing a challenge to its clinical application in bone tissue engineering.
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Helmrich U, Marsano A, Melly L, Wolff T, Christ L, Heberer M, Scherberich A, Martin I, Banfi A. Generation of human adult mesenchymal stromal/stem cells expressing defined xenogenic vascular endothelial growth factor levels by optimized transduction and flow cytometry purification. Tissue Eng Part C Methods 2011; 18:283-92. [PMID: 22070632 DOI: 10.1089/ten.tec.2011.0413] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Adult mesenchymal stromal/stem cells (MSCs) are a valuable source of multipotent progenitors for tissue engineering and regenerative medicine, but may require to be genetically modified to widen their efficacy in therapeutic applications. For example, overexpression of the angiogenic factor vascular endothelial growth factor (VEGF) at controlled levels is an attractive strategy to overcome the crucial bottleneck of graft vascularization and to avoid aberrant vascular growth. Since the regenerative potential of MSCs is rapidly lost during in vitro expansion, we sought to develop an optimized technique to achieve high-efficiency retroviral vector transduction of MSCs derived from both adipose tissue (adipose stromal cells, ASCs) or bone marrow (BMSCs) and rapidly select cells expressing desired levels of VEGF with minimal in vitro expansion. The proliferative peak of freshly isolated human ASCs and BMSCs was reached 4 and 6 days after plating, respectively. By performing retroviral vector transduction at this time point, >90% efficiency was routinely achieved before the first passage. MSCs were transduced with vectors expressing rat VEGF(164) quantitatively linked to a syngenic cell surface marker (truncated rat CD8). Retroviral transduction and VEGF expression did not affect MSC phenotype nor impair their in vitro proliferation and differentiation potential. Transgene expression was also maintained during in vitro differentiation. Furthermore, three subpopulations of transduced BMSCs homogeneously producing specific low, medium, and high VEGF doses could be prospectively isolated by flow cytometry based on the intensity of their CD8 expression already at the first passage. In conclusion, this optimized platform allowed the generation of populations of genetically modified MSCs, expressing specific levels of a therapeutic transgene, already at the first passage, thereby minimizing in vitro expansion and loss of regenerative potential.
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Affiliation(s)
- Uta Helmrich
- Cell and Gene Therapy, Department of Biomedicine, Basel University Hospital, Basel, Switzerland
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Toni R, Tampieri A, Zini N, Strusi V, Sandri M, Dallatana D, Spaletta G, Bassoli E, Gatto A, Ferrari A, Martin I. Ex situ bioengineering of bioartificial endocrine glands: A new frontier in regenerative medicine of soft tissue organs. Ann Anat 2011; 193:381-94. [DOI: 10.1016/j.aanat.2011.06.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 06/14/2011] [Accepted: 06/17/2011] [Indexed: 01/14/2023]
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Pneumaticos SG, Triantafyllopoulos GK, Basdra EK, Papavassiliou AG. Segmental bone defects: from cellular and molecular pathways to the development of novel biological treatments. J Cell Mol Med 2011; 14:2561-9. [PMID: 20345845 PMCID: PMC4373476 DOI: 10.1111/j.1582-4934.2010.01062.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Several conditions in clinical orthopaedic practice can lead to the development of a diaphyseal segmental bone defect, which cannot heal without intervention. Segmental bone defects have been traditionally treated with bone grafting and/or distraction osteogenesis, methods that have many advantages, but also major drawbacks, such as limited availability, risk of disease transmission and prolonged treatment. In order to overcome such limitations, biological treatments have been developed based on specific pathways of bone physiology and healing. Bone tissue engineering is a dynamic field of research, combining osteogenic cells, osteoinductive factors, such as bone morphogenetic proteins, and scaffolds with osteoconductive and osteoinductive attributes, to produce constructs that could be used as bone graft substitutes for the treatment of segmental bone defects. Scaffolds are usually made of ceramic or polymeric biomaterials, or combinations of both in composite materials. The purpose of the present review is to discuss in detail the molecular and cellular basis for the development of bone tissue engineering constructs.
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Affiliation(s)
- Spyros G Pneumaticos
- Third Department of Orthopaedic Surgery, Medical School, University of Athens, 'KAT' Accident's Hospital, Athens, Greece
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Güven S, Mehrkens A, Saxer F, Schaefer DJ, Martinetti R, Martin I, Scherberich A. Engineering of large osteogenic grafts with rapid engraftment capacity using mesenchymal and endothelial progenitors from human adipose tissue. Biomaterials 2011; 32:5801-9. [PMID: 21605897 DOI: 10.1016/j.biomaterials.2011.04.064] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 04/23/2011] [Indexed: 12/13/2022]
Abstract
We investigated whether the maintenance in culture of endothelial and mesenchymal progenitors from the stromal vascular fraction (SVF) of human adipose tissue supports the formation of vascular structures in vitro and thereby improves the efficiency and uniformity of bone tissue formation in vivo within critically sized scaffolds. Freshly-isolated human SVF cells were seeded and cultured into hydroxyapatite scaffolds (1 cm-diameter, 1 cm-thickness) using a perfusion-based bioreactor system, which resulted in maintenance of CD34(+)/CD31(+) endothelial lineage cells. Monolayer-expanded isogenic adipose stromal cells (ASC) and age-matched bone marrow stromal cells (BMSC), both lacking vasculogenic cells, were used as controls. After 5 days in vitro, SVF-derived endothelial and mesenchymal progenitors formed capillary networks, which anastomosed with the host vasculature already 1 week after ectopic nude rat implantation. As compared to BMSC and ASC, SVF-derived cells promoted faster tissue ingrowth, more abundant and uniform bone tissue formation, with ossicles reaching a 3.5 mm depth from the scaffold periphery after 8 weeks. Our findings demonstrate that maintenance of endothelial/mesenchymal SVF cell fractions is crucial to generate osteogenic constructs with enhanced engraftment capacity. The single, easily accessible cell source and streamlined, bioreactor-based process makes the approach attractive towards manufacturing of clinically relevant sized bone substitute grafts.
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Affiliation(s)
- Sinan Güven
- Department of Surgery, University Hospital Basel, Basel, Switzerland
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Rath SN, Pryymachuk G, Bleiziffer OA, Lam CXF, Arkudas A, Ho STB, Beier JP, Horch RE, Hutmacher DW, Kneser U. Hyaluronan-based heparin-incorporated hydrogels for generation of axially vascularized bioartificial bone tissues: in vitro and in vivo evaluation in a PLDLLA-TCP-PCL-composite system. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2011; 22:1279-1291. [PMID: 21448669 DOI: 10.1007/s10856-011-4300-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 03/16/2011] [Indexed: 05/30/2023]
Abstract
Smart matrices are required in bone tissue-engineered grafts that provide an optimal environment for cells and retain osteo-inductive factors for sustained biological activity. We hypothesized that a slow-degrading heparin-incorporated hyaluronan (HA) hydrogel can preserve BMP-2; while an arterio-venous (A-V) loop can support axial vascularization to provide nutrition for a bio-artificial bone graft. HA was evaluated for osteoblast growth and BMP-2 release. Porous PLDLLA-TCP-PCL scaffolds were produced by rapid prototyping technology and applied in vivo along with HA-hydrogel, loaded with either primary osteoblasts or BMP-2. A microsurgically created A-V loop was placed around the scaffold, encased in an isolation chamber in Lewis rats. HA-hydrogel supported growth of osteoblasts over 8 weeks and allowed sustained release of BMP-2 over 35 days. The A-V loop provided an angiogenic stimulus with the formation of vascularized tissue in the scaffolds. Bone-specific genes were detected by real time RT-PCR after 8 weeks. However, no significant amount of bone was observed histologically. The heterotopic isolation chamber in combination with absent biomechanical stimulation might explain the insufficient bone formation despite adequate expression of bone-related genes. Optimization of the interplay of osteogenic cells and osteo-inductive factors might eventually generate sufficient amounts of axially vascularized bone grafts for reconstructive surgery.
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Affiliation(s)
- Subha N Rath
- Department of Plastic and Hand Surgery, University of Erlangen Medical Center, Krankenhausstrasse 12, 91054, Erlangen, Germany
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In vitro models for the evaluation of angiogenic potential in bone engineering. Acta Pharmacol Sin 2011; 32:21-30. [PMID: 21042285 DOI: 10.1038/aps.2010.143] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Blood vessels have a fundamental role both in skeletal homeostasis and in bone repair. Angiogenesis is also important for a successful bone engineering. Therefore, scaffolds should be tested for their ability to favour endothelial cell adhesion, proliferation and functions. The type of endothelial cell to use for in vitro assays should be carefully considered, because the properties of these cells may depend on their source. Morphological and functional relationships between endothelial cells and osteoblasts are evaluated with co-cultures, but this model should still be standardized, particularly for distinguishing the two cell types. Platelet-rich plasma and recombinant growth factors may be useful for stimulating angiogenesis.
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Muller D, Chim H, Bader A, Whiteman M, Schantz JT. Vascular guidance: microstructural scaffold patterning for inductive neovascularization. Stem Cells Int 2010; 2011:547247. [PMID: 21188080 PMCID: PMC3003957 DOI: 10.4061/2011/547247] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Accepted: 08/18/2010] [Indexed: 11/20/2022] Open
Abstract
Current tissue engineering techniques are limited by inadequate vascularisation and perfusion of cell-scaffold constructs. Microstructural patterning through biomimetic vascular channels within a polymer scaffold might induce neovascularization, allowing fabrication of large engineered constructs.
The network of vascular channels within a frontal-parietal defect in a patient, originating from the anterior branch of the middle meningeal artery, was modeled using computer-aided design (CAD) techniques and subsequently incorporated into polycaprolactone (PCL) scaffolds fabricated using fused deposition modeling (FDM). Bone marrow-derived mesenchymal stem cells (MSCs) were seeded onto the scaffolds and implanted into a rat model, with an arteriovenous bundle inserted at the proximal extent of the vascular network. After 3 weeks, scaffolds were elevated as a prefabricated composite tissue-polymer flap and transferred using microsurgical technique. Histological examination of explanted scaffolds revealed vascular ingrowth along patterned channels, with abundant capillary and connective tissue formation throughout experimental scaffolds, while control scaffolds showed only granulation tissue. All prefabricated constructs transferred as free flaps survived and were viable. We term this concept “vascular guidance,” whereby neovascularization is guided through customized channels in a scaffold. Our technique might potentially allow fabrication of much larger tissue-engineered constructs than current technologies allow, as well as allowing tailored construct fabrication with a patient-specific vessel network based on CT scan data and CAD technology.
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Affiliation(s)
- Daniel Muller
- Department of Plastic, Reconstructive and Handsurgery, Klinikum rechts der Isar, Technische Universität München, 80333 München, Germany
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Scherberich A, Müller AM, Schäfer DJ, Banfi A, Martin I. Adipose tissue-derived progenitors for engineering osteogenic and vasculogenic grafts. J Cell Physiol 2010; 225:348-53. [PMID: 20626000 DOI: 10.1002/jcp.22313] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The current need for bone grafts in orthopedic and reconstructive surgery cannot be satisfied by autologous tissue transplant due to its limited availability and significant associated morbidity. Tissue engineering approaches could supply sufficient amounts of bone substitutes by exploiting the ability to harvest autologous osteogenic progenitors associated with suitable porous materials. However, the generation of clinically relevant-sized constructs is critically hampered by limited vascularization, with consequent engraftment and survival only of a thin outer shell, upon in vivo implantation. To overcome this limitation, different non-mutually exclusive approaches have recently been developed to promote or accelerate graft vascularization, from angiogenic growth factor gene delivery to surgical pre-vascularization of the construct before implantation. A simple, promising strategy involves the co-culture of vasculogenic cells to form an intrinsic vascular network inside the graft in vitro, which can rapidly anastomose with the host blood vessels in vivo. Recent data have shown that adipose tissue-derived stromal vascular fraction (SVF) may provide an efficient, convenient, and autologous source for both osteogenic and endothelial cells. When SVF progenitors were cultured in appropriate bioreactor systems and ectopically implanted, a functional vascular network connected to the host was formed concomitantly to bone formation. Future studies should aim at demonstrating that this approach effectively supports survival of scaled up cell-based bone grafts at an orthotopic site. The procedure should also be adapted to become compatible with an intra-operative timeline and complemented with the definition of suitable potency markers, to facilitate its development into a simplified, reproducible, and cost-effective clinical treatment.
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Affiliation(s)
- Arnaud Scherberich
- Tissue Engineering, Department of Biomedicine, Basel University Hospital, Basel, Switzerland
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26
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Santos MI, Reis RL. Vascularization in bone tissue engineering: physiology, current strategies, major hurdles and future challenges. Macromol Biosci 2010; 10:12-27. [PMID: 19688722 DOI: 10.1002/mabi.200900107] [Citation(s) in RCA: 299] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The lack of a functional vascular supply has, to a large extent, hampered the whole range of clinical applications of 'successful' laboratory-based bone tissue engineering strategies. To the present, grafts have been dependent on post-implant vascularization, which jeopardizes graft integration and often leads to its failure. For this reason, the development of strategies that could effectively induce the establishment of a microcirculation in the engineered constructs has become a major goal for the tissue engineering research community. This review addresses the role and importance of the development of a vascular network in bone tissue engineering and provides an overview of the most up to date research efforts to develop such a network.
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Affiliation(s)
- Marina I Santos
- 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimarães, Portugal.
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27
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Müller AM, Davenport M, Verrier S, Droeser R, Alini M, Bocelli-Tyndall C, Schaefer DJ, Martin I, Scherberich A. Platelet lysate as a serum substitute for 2D static and 3D perfusion culture of stromal vascular fraction cells from human adipose tissue. Tissue Eng Part A 2009; 15:869-75. [PMID: 19191518 DOI: 10.1089/ten.tea.2008.0498] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Fetal bovine serum (FBS) and fibroblast growth factor (FGF)-2 are key supplements for the culture of stromal vascular fraction (SVF) cells from adipose tissue, both for typical monolayer (2D) expansion and for streamlined generation of osteogenic-vasculogenic grafts in 3D perfusion culture. The present study investigates whether factors present in human platelet lysate (PL) could substitute for FBS and FGF-2 in 2D and 3D culture models of SVF cells from human lipoaspirates. SVF cells were grown in medium supplemented with 10% FBS+FGF-2 or with 5% PL. In 2D cultures, PL initially supported SVF cell proliferation, but resulted in growth arrest shortly after the first passage. Freshly isolated SVF cells cultured with both media under perfusion for 5 days within 3D ceramic scaffolds induced bone formation after subcutaneous implantation in nude mice. However, blood vessels of donor origin were generated only using FBS+FGF-2-cultured cells. This was unexpected, because the proportion of CD34+/CD31+ endothelial lineage cells was significantly higher with PL than that of FBS+FGF-2 (33% vs. 3%, respectively). These results support the use of PL as a substitute of FBS+FGF-2 for short-term culture of human SVF cells, and indicate that more specific serum-free formulations are required to maintain a functionally vasculogenic fraction of SVF cells expanded under 3D perfusion.
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Affiliation(s)
- Andreas M Müller
- Tissue Engineering Group, Laboratory 405, Department of Biomedicine, Institute for Surgical Research and Hospital Management, University Hospital Basel, Basel, Switzerland
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