A sub-atmospheric, negative pressure is applied to a growth factor starting material, such as whole blood, to release growth factors and plasma in a non-destructive medium. The released growth factors having a weight of about 70-76 kDaltons are applied in either a filtered or unfiltered state to a wound to promote healing of the wound. The released growth factors are applied topically to the area of a surface wound to effect healing. The released growth factors are also injected into soft tissue, such as a torn tendon, to promote tissue growth and healing. The growth factors are released in one method from a patient's own blood. In another method the growth factors are released from a whole blood source and freeze dried by conventional lyophilization. Then at a later date, the freeze dried product is reconstituted by normal saline for treatment of a patient's wound or for use in a surgical procedure.