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1.
J Biomed Mater Res B Appl Biomater ; 102(5): 1002-13, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24307433

RESUMEN

The production of efficient heart patches for myocardium repair requires the use of biomaterials with high elastomeric properties and controllable biodegradability. To fulfil these design criteria we propose biodegradable poly(ester urethanes) and poly(ether ester urethanes) from poly(ɛ-caprolactone) (PCL) and poly(ethylene glycol) (PEG) as macrodiols, 1,4-diisocyanatobutane as diisocyanate, l-Lysine Ethyl Ester and Alanine-Alanine-Lysine (AAK) as chain extenders. This peptide was used to tune biodegradability properties, since the Alanine-Alanine sequence is a target for the elastase enzyme. Enzymatic degradation tests demonstrated the feasibility of tuning biodegradability properties due to the introduction of AAK peptide in polyurethane backbone. Two formulations have been processed into porous scaffolds by Thermally-Induced Phase Separation (TIPS). Scanning Electron Microscopy micrographs revealed promising microstructures, which were characterized by stretched and unidirectional pores and mimicked the striated muscle tissue. Tensile tests showed that, although scaffolds are characterized by lower mechanical properties than films, these substrates have suitable elastomeric behaviors and elastic moduli for contractile and soft tissue regeneration. Viability tests on cardiomyocytes revealed the best cell response for dense film and porous scaffold obtained from PCL and Lysine Ethyl Ester-based polyurethane, with an increased viability for the porous substrate, which is ascribable to the morphological features of its microstructure. Future works will be addressed to study the in vivo behavior of these constructs and to confirm their applicability for myocardial tissue engineering.


Asunto(s)
Implantes Absorbibles , Materiales Biomiméticos , Miocardio , Miocitos Cardíacos/metabolismo , Poliésteres , Polietilenglicoles , Poliuretanos , Animales , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Línea Celular , Ensayo de Materiales/métodos , Poliésteres/química , Poliésteres/farmacología , Polietilenglicoles/química , Polietilenglicoles/farmacología , Poliuretanos/química , Poliuretanos/farmacología , Ratas
2.
Interface Focus ; 4(1): 20130045, 2014 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-24501673

RESUMEN

Bi-layered scaffolds with a 0°/90° lay-down pattern were prepared by melt-extrusion additive manufacturing (AM) using a poly(ester urethane) (PU) synthesized from poly(ε-caprolactone) diol, 1,4-butandiisocyanate and l-lysine ethyl ester dihydrochloride chain extender. Rheological analysis and differential scanning calorimetry of the starting material showed that compression moulded PU films were in the molten state at a higher temperature than 155°C. The AM processing temperature was set at 155°C after verifying the absence of PU thermal degradation phenomena by isothermal thermogravimetry analysis and rheological characterization performed at 165°C. Scaffolds highly reproduced computer-aided design geometry and showed an elastomeric-like behaviour which is promising for applications in myocardial regeneration. PU scaffolds supported the adhesion and spreading of human cardiac progenitor cells (CPCs), whereas they did not stimulate CPC proliferation after 1-14 days culture time. In the future, scaffold surface functionalization with bioactive peptides/proteins will be performed to specifically guide CPC behaviour.

3.
Macromol Biosci ; 13(8): 984-1019, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23836778

RESUMEN

One of the main challenges in tissue engineering/regenerative medicine (TERM) is the repair of damaged heart tissue, avoiding or minimizing ventricular remodeling which leads to ventricular dilatation and hypertrophy, sphericity increase, and functionality loss. Several approaches have been described to restore or enhance the contractility of the failing heart. One of them is based on the fabrication of 3D substrates that can be implanted in the infarcted area to provide an efficient support to the regenerative process. This review focuses on the strategies adopted to design and realize polymeric scaffolds for heart TERM. The implementation of different polymers and the design of scaffold architecture are described.


Asunto(s)
Materiales Biomiméticos/síntesis química , Regeneración Tisular Dirigida/métodos , Corazón/crecimiento & desarrollo , Miocardio/metabolismo , Andamios del Tejido , Enfermedades Cardiovasculares/terapia , Humanos , Nanotubos de Carbono , Polímeros/síntesis química , Impresión , Medicina Regenerativa , Ingeniería de Tejidos
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