Genetically directed synthesis provides a method to produce proteins with specific sequence and molecular size. Functional groups such as cell binding ligands, biodegradable substrates, and cell growth factors could be specifically incorporated into the target protein to make materials with novel properties.
The work described herein is focused on biosynthesis and characterization of biodegradable materials based on elastin mimetic polypeptide. Elastin mimetic tri-block proteins undergo a sol-gel transition at a lower critical solution temperature Tt, above which the protein solution is turned into virtually cross-linked hydrogel consisting of endblock aggregates bridged by hydrated midblocks. In order to make the hydrogel biodegradable, plasmin-cleavable sites were incorporated into the midblock peptide sequence.
Proteolytic cleavage experiments showed that the tri-block protein with plasmincleavable sites could be degraded by plasmin (0.5 U/mL) both in solution (1 mg/mL) and in the hydrogel state (5 wt%). The degradation rate of the hydrogel was affected by the hydrogel concentration. A 10 wt% hydrogel was not degraded by plasmin when tested under the same conditions. Differential scanning calorimetry (DSC) experiments indicated the sol-gel transition temperature of the tri-block protein was 13.0 ºC, which is lower than a previously reported tri-block protein with shorter endblocks. The results indicated that the properties of the tri-block protein such as the degradation rate and phase transition temperature could be conveniently adjusted by varying the hydrogel concentration or the sequence and size of the building blocks, which makes it a promising biomaterial as an erodible matrix in tissue engineering applications.
Table of Contents
2. Experimental Methods
3. Results and Discussion
About this thesis
|Committee Chair / Thesis Advisor|
|Biosynthesis and Characterization of Biodegradable Materials Based on Elastin Mimetic Polypeptide ()||2018-08-28||