Cell technologies in the regenerative medicine of the heart: main problems and ways of development

Abstract

The potential of heart tissues for self-regeneration is not high and supposedly limited to a small number of the niche stem cells. This makes it extremely important to develop regenerative technologies for the myocardium based on modern techniques, for instance, cell re-programming and 3D bioprinting. However, it is often difficult to differentiate the  sensational reports regularly appearing in mass media on “breakthrough” technologies from those that really have practical applications. The article sets out a point of view on the popular technologies for the regeneration of cardiac tissues and myocardium as a whole and reviews their drawbacks. The main problems of the bioprinting approach being actively developed include a low differentiation level with printing by stem cells that does not allow for a full-fledged cardiac tissue without foreign inclusions, as well as technological impossibility, when printing with stem cells, to set up their links with other cells during cell delivery in their corresponding matrix locations. Despite some optimistic reports on the good performance on stem or induced pluripotent cells injections into the myocardial injury zone that were first made public about 20  years ago, nowadays this idea seems rather doubtful, because in the recent years there has been virtually no positive effect of this procedure with a serious risk of complications. As far as growing of heart muscle elements is concerned, the main challenge is the development of the “proper” vascularization of the muscle being grown. At the same time, one has to emphasize practical feasibility of growing relatively small myocardial elements, such as sinus node.