Abstract
It has been many years since the initial research on encapsulated hemoglobin (Chang, 1957, 1964) and crosslinked hemoglobin (Chang, 1964, Chang et al, 1966, Bunn & Jandl, 1968). However, it was mainly in the last 10 years that an increasing number of academic and industrial groups have become seriously interested in this. Once this happened, it did not take too long to develop the simplier approach of crosslinked hemoglobins for clinical trials.