Modified bovine hemoglobin

In an interesting illustration of the first strategy, Sakaguchi and coworkers covalently attached hemoglobin to an aminopropyl silica particle and then polymerized organoalkoxysilanes on the surface of the hemoglobin-modified silica particle.85 The template was removed via treatment with oxalic acid.85 In more recent work, Zhang and coworkers utilized a similar approach. In their case, the sphere was made from the functionalized biopolymer, chitosan.86 The model template protein, bovine serum albumin, was covalently attached to the chitosan microsphere and then coated with a composite sol prepared from TEOS and an aminosilane.86... 

Given the hurdles and the costs associated with the development of a clinical product that is a new biologic, it is remarkable that at least five companies continue to be engaged in clinical trials of hemoglobin-based oxygen carriers (Table 2). Most of the companies are developing modified hemoglobins derived from natural sources (human or bovine red... 

Stroma-free hemoglobin preparations have been developed in response to the need for safe, infection-free, sustainable sources of blood in human medicine and to eliminate the need for cross-matching (Table 17.14). Unfortunately, unmodified free hemoglobin has too high an affinity for oxygen, is rapidly eliminated by the kidneys, causes a substantial increase in oncotic pressure and may cause renal injury. For this reason, research has focused on modified polymers of hemoglobin. At the time of writing four products are under development polymerized bovine... 

A number of other colloids have also been used or proposed as potential expanders, but have not found clinical application because of various types of severe adverse reactions. One example is Alginon which is prepared by polymerization of sodium alginate (Tomoda and Inokuchi 1959). Further, the following colloids have been studied (Thompson 1960) methylcellulose, pectin, hemoglobin, modified human globin, isinglass, bovine serum albumin, polyvinyl alcohol, and starch. 

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