Biomaterials for Cardiac Tissue Engineering

Semiotics / semiolog

Cellular Cardiomyoplasty: Clinical Application

Myocardial regeneration can be induced with the implantation of a variety of myogenic and angiogenic cell types. More than 150 patients have been treated with cellular cardiomyoplasty worldwide, 18 patients have been treated by our group. Cellular cardiomyoplasty seems to reduce the size and fibrosis of infarct scars, limit postischemic remodelling, and restore regional myocardial contractility. Techniques for skeletal myoblasts culture and ex vivo expansion using autologous patient serum (obtained from plasmapheresis) have been developed by our group. In this article we propose (1) a total autologous cell culture technique and procedures for cell delivery and (2) a clinical trial with appropriate endpoints structured to determine the efficacy of cellular cardiomyoplasty

The creation of new rotation arc to the rat latissimus dorsi musculo-cutaneous flap with delay procedures

BACKGROUND: Latissimus dorsi musculocutaneous flap is one of the most frequently performed reconstructive techniques in surgery. Latissimus dorsi muscle has two arcs of rotation. It is classified as type V muscle. This muscle can be elevated on the thoracodorsal artery to cover large defects in the anterior chest and also, the muscle can be elevated on the segmental vessels to cover midline defects posteriorly. The aim of this study was to create a new arc of rotation on a vertical axis for the muscle and investigate effectiveness of vascular and chemical delays on the latissimus dorsi muscle flap with an inferior pedicle in an experimental rat model. We hypothesized that the latissimus dorsi muscle would be based on inferior pedicle by delay procedures. METHODS: We tested two different types of delay: vascular and combination of vascular and chemical. We also tried to determine how many days of "delay" can elicit beneficial effects of vascular and combination delays in an inferior pedicled latissimus dorsi musculocutaneous flap. To accomplish this, 48 male Sprague-Dawley rats were randomly subjected to vascular or combination delay (vascular and chemical). In addition, one ear of each rat was assigned into a delay procedure and the other ear was used as a control. Results were evaluated macroscopically, and micro-angiography and histological examinations were also performed. As a result, there was a significant difference in viable flap areas between vascular delay alone and control groups (p < 0.05). RESULTS: The higher rate of flap viability was obtained in seven-day vascular delay alone. However, there was no significant difference in the viability between seven-day vascular delay and five-day vascular delay (p < 0.05), so the earliest time when the flap viability could be obtained was at five days. The rate of flap viability was significantly higher in the vascular delay combined with chemical delay than the control group (p < 0.05). CONCLUSION: The combination of vascular and chemical delays increased the rate of viability. Nevertheless, there was no significant difference between vascular delay alone and combination of vascular and chemical delays. Chemical delay did not significantly decrease the delay period. Better histological and microangiographical results were achieved in delay groups compared to control groups. We concluded that the arch of the latissimus dorsi musculocutaneous flap can be changed and the flap can be used for various purposes with the delay procedures

Development of Bioactive Patch for Maintenance of Implanted Cells at the Myocardial Infarcted Site

[EN] Ischemia produced as a result of myocardial infarction might cause moderate or severe tissue death. Studies under development propose grafting stem cells into the affected area and we hypothesize that this mechanism could be enhanced by the application of a "bioactive implant." The implant herein proposed consists of a thin porous elastomeric membrane, filled with self-assembling nanofibers and human subcutaneous adipose tissue derived progenitor cells. We describe the development and characterization of two elastomeric membranes: poly(ethyl acrylate) (PEA) and poly(caprolactone 2-(methacryloyloxy) ethyl ester) (PCLMA). Both are a good material support to deliver cells within a soft self-assembling peptide and are elastic enough to withstand the stresses arising from the heartbeat. Both developed composites (PEA and PCLMA, combined with self-assembling peptide) equally facilitate the propagation of electrical pulses and maintain their genetic profile of the seeded cells. Preliminary studies with small animal models suggest that, at short times, the bioimplant shows good adhesion with the myocardium. After three days cells loaded in the patch remain alive at the implanted site. We propose that the bioactive patch (elastomeric membranes with self-assembling peptide and cells) could increase the efficacy of future cardiac cell therapy by improving cell immobilization and survival at the affected site.The authors wish to thank the Department of Cardiac Surgery (Hospital Germans Trias i Pujol, Badalona) for their collaboration in obtaining human samples, Dr. Bago for his kind contribution in the cell transduction process and BLI analysis, and Joan Gilabert from Biomaterials Laboratory (GEMAT, IQS-School of Engineering) who kindly helped them with wettability measurements. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under Grant agreement no. 229239. This work was also supported by Grants from Ministerio de Educacion y Ciencia (SAF2011-30067-C02-01 and M. Arnal-Pastor FPU 2009-1870 grant), Red de Terapia Celular-TerCel (RD12/0019/0029), Red Cardio-vascular (RD12/0042/0047), and Fundacio La Marato de TV3 (122232).Castells-Sala, C.; Vallés Lluch, A.; Soler-Botija, C.; Arnal Pastor, MP.; Martínez Ramos, C.; Fernandez-Muinos, T.; Mari-Buye, N.... (2015). Development of Bioactive Patch for Maintenance of Implanted Cells at the Myocardial Infarcted Site. Journal of Nanomaterials. (804017). https://doi.org/10.1155/2015/804017S80401

Cardiac Tissue Engineering: Implications for Pediatric Heart Surgery

Children with severe congenital malformations, such as single-ventricle anomalies, have a daunting prognosis. Heart transplantation would be a therapeutic option but is restricted due to a lack of suitable donor organs and, even in case of successful heart transplantation, lifelong immune suppression would frequently be associated with a number of serious side effects. As an alternative to heart transplantation and classical cardiac reconstructive surgery, tissue-engineered myocardium might become available to augment hypomorphic hearts and/or provide new muscle material for complex myocardial reconstruction. These potential applications of tissue engineered myocardium will, however, impose major challenges to cardiac tissue engineers as well as heart surgeons. This review will provide an overview of available cardiac tissue-engineering technologies, discuss limitations, and speculate on a potential application of tissue-engineered heart muscle in pediatric heart surgery

Stem Cell Therapy: Pieces of the Puzzle

Acute ischemic injury and chronic cardiomyopathies can cause irreversible loss of cardiac tissue leading to heart failure. Cellular therapy offers a new paradigm for treatment of heart disease. Stem cell therapies in animal models show that transplantation of various cell preparations improves ventricular function after injury. The first clinical trials in patients produced some encouraging results, despite limited evidence for the long-term survival of transplanted cells. Ongoing research at the bench and the bedside aims to compare sources of donor cells, test methods of cell delivery, improve myocardial homing, bolster cell survival, and promote cardiomyocyte differentiation. This article reviews progress toward these goals

Fundamentals of transformed skeletal muscle used for cardiac assistance. An overview

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