According to the present invention, there is provided a delivery vehicle including sickle red blood cells carrying a moiety. The moiety can be any type of diagnostic or therapeutic agent. The present invention further provides for a method of diagnosing systemic hypoxia, acidosis, or hypertonicity by administering sickle red blood cells to a patient and detecting the location of the sickle red blood cells. Additionally, the present invention provides for a method of therapeutic treatment of systemic hypoxia, acidosis, or hypertonicity by administering sickle red blood cells to a patient. Further, the present invention provides for a delivery vehicle that specifically localizes or concentrates at systemic hypoxia, acidosis, or hypertonicity areas. The delivery vehicle is used in diagnosing and therapeutically treating these areas of hypoxia, acidosis, or hypertonicity also. The present invention further provides for a method of making the delivery vehicle described herein.