Liposome-Encapsulated Hemoglobin, TRM-645: Current Status of the Development and Important Issues for Clinical Application.

Clinical application of artificial oxygen carriers as a substitute for blood transfusion has long been expected to solve some of the problems associated with blood transfusion. Use for oxygen delivery treatment for ischemic disease by oxygen delivery has also been examined. These prospective applications of artificial oxygen carriers are, however, still in development.

Hemodilution with liposome-encapsulated low-oxygen-affinity hemoglobin does not attenuate hypothermic cerebral ischemia in rats.

Hypothermia decreases cerebral metabolism and increases hemoglobin oxygen affinity. A hypothesis that the reversal of increased oxygen affinity would further attenuate hypothermic cerebral ischemia was tested by evaluating the effects of liposome-encapsulated hemoglobin (LipoHb) with low oxygen affinity (P50 = 40-50 mmHg) on hypothermic incomplete cerebral ischemia. Wistar rats were randomly assigned to one of the following two groups: (A) exchange transfusion with LipoHb solution (Hb = 6 g/dl) (LipoHb, n = 5), (B) no exchange transfusion (control, n = 5).

Hemodilution with liposome-encapsulated low-oxygen-affinity hemoglobin facilitates rapid recovery from ischemic acidosis after cerebral ischemia in rats.

Liposome-encapsulated hemoglobin (LipoHb) with low oxygen affinity (P(50) = 40-50 mmHg) has been developed. The purpose of this study was to evaluate the effects of the LipoHb on incomplete cerebral ischemia. Wistar rats were randomly assigned to one of the following three groups: (A) exchange transfusion with LipoHb solution (Hb = 6 g/dl) (LipoHb, n = 7), (B) exchange transfusion with rat red blood cell (RBC) solution (Hb = 6 g/dl) (RBC, n = 7), (C) no exchange transfusion (control, n = 7).

Optimized retrograde cerebral perfusion reduces ischemic energy depletion.

It has been reported that retrograde cerebral perfusion (RCP) provides minimal capillary flow; however, the extent to which RCP can provide aerobic metabolic support is unknown. We evaluated whether perfusate composition optimization for RCP would preserve brain energy metabolism during hypothermic circulatory arrest (HCA) at 20 degrees C in rats. Three types of perfusates were prepared: hemoglobin-free saline, rat red blood cells, and artificial blood substitute (liposome-encapsulated hemoglobin); perfusates were made hypertonic, cooled to 20 degrees C, and oxygenated and CO(2) was administered (pH-stat management).