The present invention relates to a product and method of using albumin nanoparticles for augmenting the function or effectiveness of stem cells or precursor cells in vivo. An albumin nanoparticle suspension containing submicron albumin spheres is prepared, with the albumin spheres being capable of augmenting a function and effectiveness of stem cells or precursor cells in vivo. A predetermined amount of the albumin nanoparticle suspension is administered to a patient before or after an onset of at least one condition. The condition is one that can benefit from a healing effect of the stem cells or precursor cells. A function of the stem cells or precursor cells are augmented or improved by the albumin spheres to repair cellular or tissue damage, resulting in decreasing mortality or morbidity of the patient. The albumin spheres can be bound with fibrinogen molecules in vitro or in vivo.