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Chiu LLY, Reis LA, Momen A, Radisic M. Controlled release of thymosin β4 from injected collagen-chitosan hydrogels promotes angiogenesis and prevents tissue loss after myocardial infarction. Regen Med 2012; 7:523-33. [PMID: 22817626 DOI: 10.2217/rme.12.35] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
AIMS Acute myocardial infarction (MI) leads to fibrosis and severe left ventricular wall thinning. Enhancing vascularization within the infarct reduces cell death and maintains a thick left ventricular wall, which is essential for proper cardiac function. Here, we evaluated the controlled delivery of thymosin β4 (Tβ4), which supports cardiomyocyte survival by inducing vascularization and upregulating Akt activity, in the treatment of MI. MATERIALS & METHODS We injected collagen-chitosan hydrogel with controlled release of Tβ4 into the infarct after performing left anterior descending artery ligation in rats. RESULTS Tβ4-encapsulated hydrogel (thymosin) significantly reduced tissue loss post-MI (13 ± 4%), compared with 58 ± 3% and 30 ± 8% tissue loss for no treatment (MI only) and Tβ4-free hydrogel (control). Significantly more Factor VIII-positive blood vessels with diameter >50 µm were in the thymosin group compared with both MI only and control (p < 0.0001), showing Tβ4-induced vascularization. Wall thickness was positively correlated with the mature blood vessel density (r = 0.9319; p < 0.0001). CONCLUSION Controlled release of Tβ4 within the infarct enhances angiogenesis and presence of cardiomyocytes that are necessary for cardiac repair.
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Affiliation(s)
- Loraine L Y Chiu
- Chemical Engineering & Applied Chemistry, University of Toronto, ON, Canada
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DeQuach JA, Lin JE, Cam C, Hu D, Salvatore MA, Sheikh F, Christman KL, Christman KL. Injectable skeletal muscle matrix hydrogel promotes neovascularization and muscle cell infiltration in a hindlimb ischemia model. Eur Cell Mater 2012; 23:400-12; discussion 412. [PMID: 22665162 PMCID: PMC3524267 DOI: 10.22203/ecm.v023a31] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Peripheral artery disease (PAD) currently affects approximately 27 million patients in Europe and North America, and if untreated, may progress to the stage of critical limb ischemia (CLI), which has implications for amputation and potential mortality. Unfortunately, few therapies exist for treating the ischemic skeletal muscle in these conditions. Biomaterials have been used to increase cell transplant survival as well as deliver growth factors to treat limb ischemia; however, existing materials do not mimic the native skeletal muscle microenvironment they are intended to treat. Furthermore, no therapies involving biomaterials alone have been examined. The goal of this study was to develop a clinically relevant injectable hydrogel derived from decellularized skeletal muscle extracellular matrix and examine its potential for treating PAD as a stand-alone therapy by studying the material in a rat hindlimb ischemia model. We tested the mitogenic activity of the scaffold's degradation products using an in vitro assay and measured increased proliferation rates of smooth muscle cells and skeletal myoblasts compared to collagen. In a rat hindlimb ischemia model, the femoral artery was ligated and resected, followed by injection of 150 µL of skeletal muscle matrix or collagen 1 week post-injury. We demonstrate that the skeletal muscle matrix increased arteriole and capillary density, as well as recruited more desmin-positive and MyoD-positive cells compared to collagen. Our results indicate that this tissue-specific injectable hydrogel may be a potential therapy for treating ischemia related to PAD, as well as have potential beneficial effects on restoring muscle mass that is typically lost in CLI.
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Affiliation(s)
- Jessica A. DeQuach
- Department of Bioengineering, 2880 Torrey Pines Scenic Dr., University of California, San Diego, La Jolla, California, USA, Phone: 858 534-9628; Fax: 858 534-5722
| | - Joy E. Lin
- Department of Bioengineering, 2880 Torrey Pines Scenic Dr., University of California, San Diego, La Jolla, California, USA, Phone: 858 534-9628; Fax: 858 534-5722
| | - Cynthia Cam
- Department of Bioengineering, 2880 Torrey Pines Scenic Dr., University of California, San Diego, La Jolla, California, USA, Phone: 858 534-9628; Fax: 858 534-5722
| | - Diane Hu
- Department of Bioengineering, 2880 Torrey Pines Scenic Dr., University of California, San Diego, La Jolla, California, USA, Phone: 858 534-9628; Fax: 858 534-5722
| | - Michael A. Salvatore
- Department of Bioengineering, 2880 Torrey Pines Scenic Dr., University of California, San Diego, La Jolla, California, USA, Phone: 858 534-9628; Fax: 858 534-5722
| | - Farah Sheikh
- Medicine, 9500 Gilman Drive MC 0613-C, University of California, San Diego, La Jolla, California, USA, Phone: 858 534-9628; Fax: 858 534-5722
| | - Karen L. Christman
- Department of Bioengineering, 2880 Torrey Pines Scenic Dr., University of California, San Diego, La Jolla, California, USA, Phone: 858 822-7863; Fax: 858 534-5722
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