Our body can replace as many cells as it desires, but not for all organs. Liver on one side has most and brain on other side least regeneration capability out of all organs. Cardiac cells are also hardly regenerated and pose a grave threat in case of cardiac arrest.
Back in 2011 a direct reprogramming of skin cells that bypasses i-PS led to a totally new paradigm. Sheng Dings group from Scripps Research Institute reprogrammed stem cells in such a way that laborious process of going through embryonic-stem cell generation was evaded. In 2013 Marko Mihovilovics group in Vienna claimed to have created certain chemicals that can regulate the differentiation process of progenitor cells and turn them into cardiac cells.
A team of researchers recently generated cardiac cells that can beat and are observable under microscope only. These cardiac cells created from tissues like skin and blood have the talent to multiply. Normal cardiac cells after they wear and die are irreplaceable or regenerate very poorly. Due to this reason cardiac attacks are often fatal. One of the main disadvantages of any organ or tissue replacement is the denial by immune system. However these beating cardiac cells unlike embryonic stem cells are obtained from patient itself and hence have least chances of being getting rejected. Though more advancement in this area is needed, but this achievement by Glen Tibbits group (Canada) can have a great impact on personalized or tailored treatment in near future.