Collagen graft copolymer

A graft copolymer of collagen (as well as other proteinaceous materials) with methyl methacrylate has been made by polymerization initiated by tri-n-butylborane (31). Kudaba and co-workers also modified collagen by treating it with epichlorohydrin (32, 33) or epoxy resins (34) with BFs Et20 as catalyst. Such treatments could be valuable for improving certain properties of leather, but the experimental conditions preclude their use for clinical applications. 

The appearance of the products of the reaction of collagen and various monomers often varied considerably from the original collagen powder 45, 48). With some monomers, the graft copolymer consisted of powders while with others mats or films were formed. The modification of surface properties could often be detected by visual inspection. 

Figure 2. The wound half life, ti/2, is shown to depend on the degradation rate, R, of collagen-gra/t-glycos-aminoglycan membranes which were contacted with the woundbed of fresh skin wounds in guinea pigs, prepared by full-thickness excision. R, expressed in enzyme units, was varied by controlling the residence time of the graft copolymer in aqueous glutaraldehyde.

Cross-linked PVP is applied as a semipermeable membrane [492]. Furthermore, PVP can be used for the encapsulation of hydrophobic material [492]. Poly(iV-vinylpyrrolidone-co-styrene) was found to be an extraordinary catalyst in two-phase reactions [532]. For special applications one can design copolymers of NVP with different olefins and diolefins, or it is possible to graft NVP onto cellulose, polyolefins, keratin, collagen, and others, or to graft PVP with olefins [492,533-542]. 

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