Carbon dioxide, waste products , heat , hormones are transported by plasma.
What Is Transported In The Plasma?
Blood is composed of two general parts: The formed elements (RBC, WBC, Platelets) and plasma.
RBC's have a transportation function related to oxygen and to a smaller extent carbon dioxide but other than that virtually everything is transported in the plasma.
These things include:
Proteins produced in the body (particularly the liver)
Nutrients absorbed from digested food from the small intestine
Hormones
Ions (electrolytes)
Gases and waste products