Master of Science
Dr. Elizabeth R. Gillies
Polyesters have been used for many biomedical applications ranging from sutures to drug delivery vehicles. However, their bulk degradation results in an accumulation of acidic byproducts, which is detrimental to the human body. In order to circumvent this problem, as well as to impart new properties and functions to polymers for biomedical applications, poly(ester amide)s (PEAs) have been proposed as a different class of biodegradable polymers. However, up to date, there exists no way to stimulate the degradation of these polymers.
The Gillies research group has previously incorporated self-immolative spacers into polymers and has been able to stimulate their degradation by adding the appropriate trigger. The objective of this thesis was to incorporate amino acids capable of 1,5-cyclization into the PEA backbone such that upon activation of the functional moiety, a 1,5-cyclization was induced, leading to degradation of the PEA backbone. PEAs containing L-2,4-diaminobutyric acid and DL-homocysteine were synthesized and their degradation was monitored in solution, and in films. It was found that the polymers containing the self-immolative spacers degraded faster than their controls under specific triggers (i.e. change in pH, reducing conditions, UV light), thereby allowing polymer degradation to be accelerated under these specific conditions.
Mejia, Jose Samuel, "Controlled Degradation of Poly(ester amide)s via Cyclization of Pendant Functional Groups" (2012). University of Western Ontario - Electronic Thesis and Dissertation Repository. Paper 954.