Faculty Directory

Payne, Gregory F.

Payne, Gregory F.

Professor
Fischell Department of Bioengineering
5115 Plant Sciences Building
Website(s):

EDUCATION

Ph.D., The University of Michigan, 1984

HONORS AND AWARDS

  • Guest Professor, Wuhan University, China

Nanobiotechnology, biofabrication (construction using biological materials and mechanisms), stimuli-responsive biopolymers (e.g., chitosan and alginate), enzymes (e.g., tyrosinase and microbial transglutaminase), electroaddressing, renewable resources.  

Biology is expert in creating functional nanoscale components (e.g., proteins) and assembling them over a hierarchy of length scales to create functional structures (e.g., organs). Our lab aims to enlist biology’s materials, mechanisms and lessons to fabricate high-performance soft matter that is cheap, safe and sustainable. In particular, we focus on building structure/function using stimuli-responsive biological polymers (especially polysaccharides), enzymes (especially tyrosinase and transglutaminase), and redox-active phenolics. Currently we are collaborating with several groups from around the world in three primary areas of research.

Biofabrication of the Bio-device Interface

The last century witnessed spectacular advances in both microelectronics and biotechnology yet there was little synergy between the two. A challenge to their integration is that biological and electronic systems are constructed using divergent fabrication paradigms. Biology fabricates bottom-up with labile components while microelectronic devices are fabricated top-down using methods that are “bio-incompatible”. Biofabrication – especially the use of biological materials and mechanisms for construction – offers the opportunity to span these fabrication paradigms by providing convergent approaches for building the bio-device interface.

Figure 1 (below) illustrates our vision for biofabricating the bio-device interface. Device-imposed stimuli provide the cues to initiate assembly and control spatiotemporal localization. Integral to this vision are stimuli-responsive materials that recognize the device-imposed cues and respond by undergoing a sol-gel transition to deposit as stable hydrogel films. Importantly, hydrogel electrodeposition provides a mechanism to trigger self-assembly over a hierarchy of length scales and yields a water-rich microenvironment that is generally compatible with labile biological systems. A second mechanism for hierarchical assembly employs enzymes that covalently conjugate macromolecules (e.g., proteins) to the self-assembled matrix. Through various collaborations, we are expanding and applying these biofabrication tools to biofunctionalize microfluidic lab-on-a-chip devices.
 

biofabrication
Fig. 1. Biofabrication to build the bio-device interface.
Biofabrication 2022002 (2010).

 

Biofabricated Redox-capacitor to Establish Bio-device "Connectivity"

Biology and electronics each possess incredible signaling processing capabilities – but they use different signaling modalities. Biology signals using ions and molecules while electronic devices use electrons to process information. Oxidation-reduction (i.e., redox) reactions provide the bridge to connect biological and electronic communication.

We recently fabricated a bio-based redox-capacitor by depositing a thin film of the polysaccharide chitosan and then modifying this film with catecholic moieties. Catechols/quinones are common redox-couples in biology and we observed that these moieties confer redox-activity to the chitosan film. Importantly, the catecholic matrix is redox-active (it can exchange electrons with appropriate mediators) but is non-conducting (it cannot exchange electrons directly with the underlying electrode). These physicochemical properties allow the catecholic matrix to be switched between two stable states (oxidized and reduced) and also allows the matrix to gate, amplify and partially-rectify mediator currents. Also, this catecholic matrix can exchange electrons with bio-relevant oxidants and reductants (e.g., NADH and ascorbate). As illustrated in Figure 2 (below), this catecholic redox-capacitor can interconnect biological and electrical inputs/outputs for information processing.

catecholic matrix
Figure 2. The catecholic matrix (QH2/Q) can exchange electrons with the redox-active metabolites pyocyanin (PYO) and acetosyringone (AS) that can access cellular redox-state. In addition, these metabolites can shuttle electrons between the electrode and the matrix. These properties allow cyclic potential inputs to be imposed to generate steady output currents that possess information of biological/environmental redox activities.

 

Biopolymeric Materials as High-performance Alternatives

Traditionally, biopolymeric materials have been viewed as bio-based alternatives to synthetic polymers. The commonly-stated advantages of bio-based polymers are their sustainable source and their environmental-friendliness (i.e., biodegradability). However, biopolymers often possess functionality that allows them to compete in terms of performance. In fact, the high-performance capabilities of proteins are well-established: proteins are expressed with controlled sequence, size and shape, and they possess unparalleled capabilities for molecular recognition and catalysis.

Our lab focuses on polysaccharides and phenolics. Polysaccharides are routinely used in food and consumer applications because they possess valuable functional properties (e.g., viscosifying and gelling properties). Often these properties change dramatically in response to small changes in environmental conditions (e.g., in pH, temperature and solution composition). Phenolic-based materials (e.g., lignin and melanin) are more abundant in nature than either proteins or nucleic acids, yet they are seldom studied. Often phenolics possess optical and redox properties that confer protective functions. Over the long term, our lab’s biofabrication research should promote the broader use of polysaccharides and phenolics for food, cosmetic, pharmaceutical, biotechnology and medical applications where performance and biological compatibility are essential.

Coupling Electrodeposition with Layer-by-Layer Assembly to Address Proteins within Microfluidic Channels. Advanced Materials. 23: 5817-5821 (2011).

Electroaddressing Functionalized Polysaccharides as Model Biofilms for Interrogating Cell Signaling. Advanced Functional Materials. 22: 519-528 (2012).

Electrodeposition of a Biopolymeric Hydrogel: Potential for One-step Protein Electroaddressing. Biomacromolecules. 13: 1181-1189 (2012).

Biofabrication of Stratified Biofilm Mimics for Observation and Control of Bacterial Signaling. Biomaterials. 33: 5136-5143 (2012).

Biofabricating Multi-functional Soft Matter with Enzymes and Stimuli-Responsive Materials. Advanced Functional Materials. In Press (2012).

Redox Cycling and H2O2-Generation by Fabricated Catecholic Films in the Absence of Enzymes. Biomacromolecules, 12: 880-888 (2011).

Biomimetic Fabrication of Information-rich Phenolic Chitosan Films. Soft Matter, 7: 9601-9615 (2011).

Redox Capacitor to Establish Bio-device Redox-Connectivity. Advanced Functional Materials. 22: 1409-1416 (2012).

Payne, G.F., P.B. Smith (Eds). “Renewable and Sustainable Polymers.” American Chemical Society Press. Washington, DC (2011).

Bridging the Gap between Microelectronics, Biological Systems

UMD researchers receive $1.5 M NSF grant to develop first-of-kind bioelectronics.

Schizophrenia drug monitoring device research featured on IEEE Sensors Letters cover

The paper culminates a four-year collaboration among Clark School, IBBR and University of Maryland School of Medicine researchers.

Research Review: Combating biofilms with microsystem devices

New microsystems detect, treat bacterial biofilms—the source of many post-operative infections; latest device can sense and treat biofilm inside urinary catheters.

UMD Researchers Make Strides in Schizophrenia Diagnosis Research

Blood test could help doctors more quickly diagnose schizophrenia and other disorders.

Hadar Ben-Yoav accepts tenure-track position at Ben-Gurion University

Former ISR postdoc will join the Dept. of Biomedical Engineering.

UMD Researchers Bridge Gap between Microelectronics, Biological Systems

“Electronic modulation of biochemical signal generation” published in Nature Nanotechnology

Preventing Costly, Life-Threatening Catheter Infections

Deutsch Foundation-sponsored Clark School research offers multi-pronged attack on major medical problem.

Bacteria Programmed to Re-Create UMD Logo

Feat part of larger body of Clark School research into preventing infections.

Rubloff Group Research Selected for Highlights in Chemical Technology.

Paper covers advances in lab-on-a-chip technology.

Ghodssi, Rubloff part of $2 million NSF grant

Cellular and biomolecular engineering research to focus on biofunctionalized devices.

Thermo-Bio-Lithography (ISR IP)

This IP is available to license.