Figure 7.
A) Scheme shows the reversible formation of imine-, alkylhydrazone-, acylhydrazone-, and oxime-based linkages between an aldehyde containing gel and amine, hydrazide, acylhydrazide, and oxyamine functional groups and. B) A plot of the relative half-life (t1/2) stabilities of imine, oxime and hydrazone linkages as a function of pH. The half-lives were estimated based on reported pseudo 1st order rate constants, where t1/2 = ln 2/k. Schemes of the aldehyde-functionalized peptide gels used to prolong the delivery of C) doxorubicin D) gemcitabine, based on hydrolytic stability of the corresponding imine complex.