Erythrocytes as carriers for heparin. Preliminary in vitro and animal studies

Encapsulation of heparin into resealed carrier erythrocytes may be useful in the prevention of thromboembolism because heparin may be released locally during retraction of fresh thrombi. Heparin encapsulation in human and canine erythrocytes was achieved by hypo-osmotic dialysis with 44% and 36% encapsulation, respectively. Encapsulated heparin did not leak from carrier erythrocytes in vitro. In vivo survival of heparin-loaded carrier erythrocytes in dogs was biphasic: After an initial phase of cell loss the carrier cells survived in circulation with a half-life of 28 h. The present results seem to warrant clinical studies with heparin-loaded carrier erythrocytes.