Certain types of cells located in bone marrow may help the body recover after an injury. These cells may be able to help the body repair heart muscle that has been damaged from a heart attack. NX-CP105 is a new investigational drug that is made up of these special types of bone marrow cells, which come from another person. NX-CP105 has not been approved for sale or general use by the Food and Drug Administration (FDA), and this study will be the first time that NX-CP105 is given to human beings.