Polyelectrolyte Complex Hydrogels: A Platform for Wet Adhesives and 3D Bioprinting Inks
Samanvaya Srivastava, UCLA
11:00 a.m., September 13, 2022 | Carey Auditorium, 107 Hesburgh Library
Significant advances in emulating natural glues have led to a diversity of wet adhesive chemistries. However, most current adhesives cure slowly in unprotected aqueous environments, leading to precursor deactivation, dilution, and weak adhesion.
In this talk, I will discuss our progress in developing a self-assembled scaffolding based on polyelectrolyte complex-interpenetrating network (PEC-IPN) hydrogels for wet adhesives and 3D printing inks. These hydrogels are fabricated by curing polymeric adhesive (or ink) precursors in protected environments provided by self-assembled polyelectrolyte complex (PEC) hydrogels, thus mitigating precursor dilution.
In the resulting PEC-IPN hydrogels, the PEC network also features a mesoscale hierarchical structure, contributing to superior mechanical and adhesive performance of the adhesives and printed constructs. Model PEC-IPN hydrogels comprising a PEC network composed of oppositely charged block polyelectrolytes and a covalently crosslinked tetra-PEG network will be demonstrated to serve as a material platform for robust and tough wet adhesives. X-ray scattering investigations will establish the persistence of the PEC network upon the inclusion of tetra- PEG chains in it and their subsequent photocrosslinking. Simultaneously, marked improvements in shear and tensile strengths of PEC-IPN hydrogels upon incorporating the covalent tetra-PEG network, even as a minor component, will be demonstrated. We will conclude by demonstrating proof-of-concept demonstrations of the utility of PEC-IPN hydrogels as bioadhesives and as inks for 3D bioprinting applications.
Samanvaya (Sam) Srivastava is an Assistant Professor of Chemical and Biomolecular Engineering at UCLA. He completed his undergraduate and master’s degrees from IIT Kanpur and his Ph.D. from Cornell University, all in Chemical Engineering. At IIT Kanpur, he worked with Prof. Ashutosh Sharma on instabilities in thin films. At Cornell, he worked with Prof. Lynden Archer on structure and properties of polymer nanocomposites and nanoparticle dispersions.
After his Ph.D., Samanvaya pursued postdoctoral research on polyelectrolyte solutions and complexes with Prof. Matthew Tirrell at the University of Chicago. Samanvaya’s current research interests are in investigating the influence of diverse intermolecular interactions on material structure and properties, with a broader aim to combine this fundamental understanding with molecular engineering and self-assembly processes to improve materials design.
He has published over 30 research articles and has received several awards, including Austin Hooey Graduate Research Excellence Recognition Award at Cornell University, RSC Researcher Mobility Grant, AIChE 35 under 35 award, the NSF CAREER Award, and the ACS PMSE Young Investigator Award. Lab website: https://www.srivastava-lab.net/