Srinivasa Raghavan (UMD Department of Chemical & Biomolecular Engineering): How Biophysical Principles Enable the Design of New (and Useful) Biomaterials

Speaker: Srinivasa Raghavan, UMD Department of Chemical & Biomolecular Engineering

Host: Jeffery Klauda

Abstract:

Our laboratory engineers polymers, surfactants, and colloids into structured materials. We often create ‘smart’ (i.e., responsive) materials whose properties can be transformed by an external stimulus. Two biophysical principles underlie a lot of our work.  

First is the principle of self-assembly, i.e., spontaneous assembly driven by thermodynamics. For example, polymer chains with both hydrophilic and hydrophobic parts self-assemble by hydrophobic interactions. We have created a self-assembling biopolymer that connects biological cells into a 3-D network. Thus this polymer converts liquid blood into a gel and thereby stops bleeding from wounds. This research has been translated into a commercial product called Rapid-Seal Wound Gel that is available at pharmacies across the country. 

Second is the principle of directed assembly, where the system is driven into a non-equilibrium state, e.g., by external fields. For example, hydrogels of cationic polymers can be strongly adhered to biological tissues by applying an electric field (DC, 10 V) for 20 s. This adhesion persists indefinitely thereafter. Applying the DC field with reversed polarity eliminates the adhesion. Electroadhered gel-patches provide a robust seal over cuts and tears. These studies pave the way for performing surgeries without sutures.

Seminars start at 4:00 pm, and refreshments will be served at 3:45 pm. All seminars are held in the Conference Room (1116) of the Institute for Physical Science and Technology (IPST) Building unless otherwise noted.