Break | AIChE


Protein hydrogels have many unique characteristics such as their biocompatibility, controllable pore size, and adjustable mechanical properties, making them ideal candidates for biomedical applications. Using protein hydrogels as a building block, the protein secondary structure can be manipulated to impart desired properties for particular applications such as stimuli response and drug binding. Our lab has generated a mechanically responsive triblock polymer that comprises two domains, one derived from the N-terminal coiled-coil region of the non-collagenous glycoprotein cartilage oligomeric matrix protein (C), capable of binding small hydrophobic molecules, and the other from the elastin-like polypeptide motif (E), which experiences an inverse transition temperature from a soluble random coil to a ß-spiral structure. This triblock polymer is rationally designed, in which the two domains are linked as C-E-C with the E motif flanked between two C domains, which combines the respective functions of each domain. The negative control CL44AECL44A was constructed bearing a previously characterized impaired CL44Adomain deeming the triblock inelastic, unstructured and incapable of binding to small molecules. CEC and its counterpart CL44AECL44A were structurally assessed via circular dichroism (CD) for secondary structure, as well as accessed for thermostability, mechanical integrity, and small molecule binding capability. Furthermore, the two constructs were assessed for micellar-like particle formation to elicit the driving factors behind the formation of hydrogels. The CEC triblock demonstrated enhanced mechanical properties, structural integrity and small molecule encapsulation over its counterpart as well as compared to previously characterized variants bearing the C domain, such as EC, CE and ECE. These capabilities are a result of the addition of a second C domain. Moreover, CEC exhibited significantly denser micellar-like particle formation compared to CL44AECL44A. Since CEC demonstrates promising biomedical applications, further studies to fabricate a free standing hydrogel consisting of the CEC polymer with patterning to substrate capabilities are underway.