Polymer-peptide hybrids

 

The underlying structural blocks of nature’s high performance materials are polypeptides, which exhibit secondary structures that contribute to the high degree of molecular order observed in biohybrid materials. Our approach emphasizes the solid-state organization and performance of polurethane/urea-peptide motifs. This new class of bio-inspired elastomeric, polymer peptide hybrids exhibit a nanostructured morphology with multiple levels of organization that have applications as responsive films/fibers, injectable hydrogels, and shape memory systems.  Understanding of architecture, connectivity, and non-covalent/covalent interactions are key drivers of these systems.

Post-doctoral Associate: Dr. Sourav Chatterjee

Graduate Student: Daseul Jang

Polymer-reinforced gels and gel composites

The underlying structural blocks of nature’s high performance materials are polypeptides, which exhibit secondary structures that contribute to the high degree of molecular order observed in biohybrid materials. Our approach emphasizes the solid-state organization and performance of polurethane/urea-peptide motifs. This new class of bio-inspired elastomeric, polymer peptide hybrids exhibit a nanostructured morphology with multiple levels of organization that have applications as responsive films/fibers, injectable hydrogels, and shape memory systems.  Understanding of architecture, connectivity, and non-covalent/covalent interactions are key drivers of these systems.

Post-doctoral Associate: Dr. Yanchun Tang

Hygromorphic actuators

Fiber constructs are prevalent in natural systems, from collagen fiber networks in tendon to tough spider silk fibers. We are particularly intrigued by the impact of synthetic fiber orientation, alignment, manufacturing, and reinforcement on mechanics and functionality. Seed pods are one such biological material that utilizes a fibrous architecture to drive actuation.  Specially, these systems exhibit hygromorphism or the ability to change shape in response to humidity or water.  We have explored the fabrication of responsive composite systems utilizing high modulus, electrospun and low molecular gelators as fibrous fillers utilizing concepts of interfacial assembly, transport, bias, and orientation.

Graduate Student: Francis Klincewicz

Supramolecular interpenetrating networks (IPNs) and elastomers

Supramolecular interactions may hold the key to the development of elastomers with a tailored elastic response and improved mechanics, such as observed in the muscle protein titin. It is the dynamic nature of the supramolecular interaction that we have exploited in the design of tough supramolecular elastomers that superimpose covalent and non-covalent interactions to tailor tensile response. Key to this investigation is the connection between the thermodynamic and kinetic phenomena of the supramolecular bond to the underlying toughening and dynamic restructuring mechanisms exhibited in these nature-inspired supramolecular systems. Our innovative material platform allows for systematic study of the mechanism/kinetics of UV irradiation, phase separation, and interfacial interactions within a supramolecular framework and its connection to mechanics and structural development.

Graduate Student: Chase Thompson and Akash Vaidya

Extruded films, fibers, and hydrogels

 

Multilayer co-extrusion or forced assembly is a process by which immiscible polymers are co-extruded through a series of ‘multiplier’ dies to form layered, large-scale films with layer thicknesses ranging from the nano- to micro-scale. This multilayer platform technology has been previously utilized in our group to probe the confinement-induced assembly of self-assembling materials and its connection to tunable mechanics.

Recent innovations in multilayer co-extrusion technology have translated to the fabrication of melt-extruded polymeric rectangular fiber mats and composites. Distinct advantages of this modular approach over other traditional fiber processing techniques include scalability, environmentally-friendly conditions, and the ability to obtain cross-sectional dimensions on the nanoscale. In one area of exploration, the mechanics and structural features of biologically relevant, high surface area fiber mats are examined. Functional fiber substrates for tissue engineering are obtain via facile surface modification, blending, and inclusion of the therapeutics. We also focus on this fiber technology as a new platform for the development of reinforced hydrogels via an in situ approach. This manufacturing strategy allows for strategic control of hydrogel architecture, fiber alignment and loading, compressive stability and stiffness. Promising results related to cell adherence and growth are highlighted for these extruded hydrogel scaffolds.

Graduate Student: Kris Van de Voorde