Biomedical Engineering Reference
In-Depth Information
healthy rat hearts, EHTs were vascularized and survived. Moreover, a
multiloop EHT was formed by stacking five circular EHTs to increase
graft size and facilitate implantation [31]. Multiloop EHT graft
implantation experiments in MI rats showed electrical coupling to
the native myocardium, prevention of myocardium remodeling, and
improvement of cardiac function. Furthermore, they also created
pouch-like EHTs, which can be slipped over adult rat hearts [32].
Giraud et al. combined rat skeletal myoblasts with a collagen and
Matrigel mixture to create an engineered biodegradable skeletal
muscle graft (ESMG) and investigated its functional effect after
implantation on the epicardium of an infarcted heart [33]. After seven
days of in vitro culture, embedded cells differentiated into randomly
oriented myotubes. Four weeks after ESMG implantation, neovessel
formation and improvement of cardiac function were observed.
Porous scaffolds were used by Chachques et al. when they evaluated
the potential of a type I collagen sponge matrix seeded with HUCBCs
using a mouse MI model, which prevented improved LV function and
ventricular wall remodeling, following myocardium infarction [34].
They also performed a clinical study in ischemic patients (named
the Myocardial Assistance by Grafting a New Bioartificial Upgraded
Myocardium [MAGNUM] trial), which showed that bone marrow cell
therapy associated with surgical implantation onto the epicardium
of a cell-seeded collagen matrix prevents myocardial wall thinning
and improves diastolic function [35, 36].
5a.4.4 Gelatin
Gelatin is largely composed of denatured collagen, which is
mainly obtained from connective tissue found in bones, ligaments,
tendons, and cartilage. It is commonly used as a gelling agent in
food, pharmaceuticals, photography, and cosmetic manufacturing.
In the field of tissue engineering, gelatin has been utilized as a
biodegradable material for fabricating scaffolds. Li et al. implanted
constrictive cardiac patches prepared by seeding fetal rat ventricular
muscle cells into a biodegradable gelatin mesh, either into the
subcutaneous tissue of adult rat legs or onto myocardial scar tissue
in a cryoinjured rat heart [37]. Five weeks after the implantation
onto subcutaneous tissue, the grafts survived and contracted
spontaneously. Although the grafts also survived and formed
junctions with the recipient heart cells after implantation onto an
