Mechanomorphology of Colloidal Gel Regulates Endothelial Cell Organization
Nair, Smruti Krishnan
MetadataShow full item record
Colloidal gels have been established as a bottom-up strategy by infusing micro- or nanoparticles as building blocks to form functional scaffolds. Strong attraction between colloid particles over short distance leads to their aggregation forming clusters that have a fractal structure in the form of either branched or open and tenuous networks. The spectrum offered by oppositely charged colloidal gels coming together forming colloids has numerous advantages most notably increased rheological and structural strength. Complementary interfacial charges of colloidal particles can be used to assemble the particles with distinct mechanomorphology. Gelatin based colloidal gels are distinct in their morphological and mechanical characteristics. Both gel microstructure and mechanics can be regulated from the organization of colloidal building units in the microscopic scale. Electrostatic crosslinking achieved by altering the counter ions to the positively charged gelatin colloidal particles self-assemble the particles into distinct morphological complexes through modulation of aggregation kinetics. Specifically, the counter ions are varied by their structure ranging from ionic salts (sodium chloride) to polyions (polyacrylic acid), and oppositely charged gelatin colloidal particles to modulate the aggregation of particles into distinct patterns, where salts can induce clustering of particles into dense structure while polyacrylic acid can induce bridging interaction to form tenuous branched networks while oppositely charged gelatin colloid can lead to heterogeneous structure.We utilized this approach to develop and characterize gelatin based colloidal gels where both gel microstructure and mechanical characteristics were regulated from the organization of colloidal building units. Assembly of colloidal particles into gel was characterized by microscopic and rheological approaches and these gels were used to analyze the response of endothelial cell organization. Results show that endothelial cells responded to the mechanomorphology of the colloidal gels. In summary, gelatin based colloidal gels developed through modulation of aggregation kinetics provides a versatile material engineering tool to design 3D colloidal gels with distinct microstructure and platform to regulate cell organization.