About

Timothy J. Deming is a professor with a focus on chemical biology, materials, and organic chemistry. He received a B.S. in Chemistry from the University of California, Irvine in 1989, and a Ph.D. in Chemistry from the University of California, Berkeley in 1993 under the guidance of Bruce Novak. Following a NIH postdoctoral fellowship at the University of Massachusetts, Amherst with David Tirrell, he joined the faculty at the University of California, Santa Barbara in 1995, where he held a joint appointment in the Materials and Chemistry Departments, and was promoted to Full Professor in 2003. Currently, he serves as the Chair of the Bioengineering Department at UCLA. His research interests include the synthesis, processing, characterization, and evaluation of biological and biomimetic materials based on polypeptides. His work emphasizes the development of materials from renewable resources that are biocompatible and biodegradable, with unique self-assembling properties. He utilizes innovative chemistry techniques to synthesize complex materials, process them into ordered assemblies, and characterize their nanoscale structure and biological function. His interdisciplinary approach fosters innovation and exploration into new areas of biomaterials and polymer science. Deming has received numerous awards and honors, including young investigator awards from the National Science Foundation, the Office of Naval Research, and other prestigious foundations, as well as being a Fellow of the American Institute of Medical and Biological Engineering and recipient of the Fulbright-Tocqueville Distinguished Chair Award.

Research topics

• Chromatography
• Chemistry
• Organic chemistry

Selected publications

• BPS2025 - Antimicrobial polylysine-phage conjugates for improved biocompatibility

  Biophysical Journal · 2025-02-01

  article
  PublisherDOI

• BPS2025 - Antimicrobial polylysine-phage conjugates for improved biocompatibility

  Biophysical Journal · 2025-02-01

  article
  PublisherDOI

• Shape Transformation of Poly(<scp>l</scp>-methionine sulfoxide)-<i>b</i>-poly(dehydroalanine) Vesicles

  ACS Macro Letters · 2025-09-17

  articleOpen accessSenior authorCorresponding

  The controlled transformation of polymeric vesicles into stable nonspherical morphologies is of interest as a means to mimic cells, create nanoreactors, and improve their potential for therapeutic delivery applications. We have found that the poly(dehydroalanine) segments in poly(l-methionine sulfoxide)x-b-poly(dehydroalanine)y, MOxADHy, copolypeptides form membranes that provide plasticity and selective permeability in DMSO/water mixtures, which allow the predictable control of vesicle shape by the variation of dialysis conditions. The findings of this study expand vesicle shape transformation methods to these biodegradable block copolypeptide vesicles, which are amenable to development for applications in therapeutic delivery.

  PublisherOA PDFDOI

• Triggered Inversion of Dual Responsive Diblock Copolypeptide Vesicles

  Journal of the American Chemical Society · 2025-02-20 · 10 citations

  articleOpen accessSenior authorCorresponding

  We report the synthesis of amphiphilic poly(l-methionine sulfoxide)x-b-poly(dehydroalanine)y, diblock copolypeptides, MOxADHy, and their self-assembly into submicrometer-diameter unilamellar vesicles in aqueous media. The formation of vesicles was observed over an unprecedented range of copolypeptide compositions due to the unique properties and chain conformations of ADH hydrophobic segments. These copolypeptides incorporate two distinct thiol reactive components where each segment can respond differently to a single thiol stimulus. Incubation of MO35ADH30 vesicles with glutathione under intracellular mimetic conditions resulted in vesicle disruption and release of cargo. Further, incubation of MO35ADH30 vesicles with thiolglycolic acid resulted in a reversal of amphipilicity and successful in situ inversion of the vesicle assemblies. This conversion of biomimetic polymer vesicles into stable inverted vesicles using a biologically relevant stimulus at physiological pH and temperature is unprecedented. These results provide insights toward the development of advanced functional synthetic assemblies with potential uses in biology and medicine.

  PublisherDOI

• Peptide Materials

  Biomacromolecules · 2025-07-14 · 2 citations

  editorial1st authorCorresponding

  Over the past three decades, the field of peptide-based materials has been rapidly expanding and evolving, becoming a multidisciplinary area, with new developments and applications being consistently discovered. The purpose of this Peptide Materials Special Issue is to highlight research presented at the first Gordon Research Conference on Peptide Materials in January, 2023. Consequently, we invited eminent scientists with primary research interests in Peptide Materials to contribute original research articles or short reviews in this area. This thematic issue is focused on the materials aspects of peptides and their derivatives and mimics, including both fundamental research in peptide design, synthesis, assembly, micellization, gelation, and coacervation, as well as disparate technological applications, including functional materials for energy storage, catalysis, drug delivery, regenerative medicine, adhesion, protein purification, and nanotechnology. As peptides are composed of amino acids─the fundamental building blocks of proteins─they serve as a natural bridge between small-molecule supramolecular assemblies and large biomacromolecular constructs. Their ability to adopt well-defined secondary and tertiary structures, undergo hierarchical self-assembly, and exhibit tunable biochemical properties and distinct structural features highlights their importance and relevance within the broader landscape of biomacromolecular research. The peptide materials field has become a well-established, interdisciplinary area that attracts chemists, chemical engineers, material scientists, physicists, and biomedical engineers. The papers collected in this special issue demonstrate the growing recognition of peptides, polypeptides, proteins, and their derivatives and mimics as a versatile and critical class of biomacromolecules, poised to drive continued growth and innovation across diverse scientific and technological disciplines.

  PublisherDOI

• Sulfur Switches for Responsive Peptide Materials

  Accounts of Chemical Research · 2024-02-19 · 16 citations

  articleOpen access1st authorCorresponding

  ConspectusThere is considerable recent interest in the synthesis and development of peptide-based materials as mimics of natural biological assemblies that utilize proteins and peptides to form organized structures and develop beneficial properties. Due to their potential compatibility with living organisms, synthetic peptide materials are also being developed for applications such as cell grafting, therapeutic delivery, and implantable diagnostic devices. One desirable feature for such applications is the ability to design materials that can respond to stimuli by changes in their structure or properties under biologically relevant conditions. Peptide and protein assemblies can respond to stimuli, such as changes in temperature, solution pH, ions present in media, or interactions with other biomacromolecules. An exciting area of emerging research is focused on how biology uses the chemistry of sulfur-containing amino acids as a means to regulate biological processes. These concepts have been utilized and expanded in recent years to enable the development of peptide materials with readily switchable properties.The incorporation of sulfur atoms in polypeptides, peptides, and proteins provides unique sites that can be used to alter the physical and biological properties of these materials. Sulfur-containing amino acid residues, most often cysteine and methionine, are able to undergo a variety of selective chemical and enzyme-mediated reactions, which can be broadly characterized as redox or alkylation processes. These reactions often proceed under physiologically relevant conditions, can be reversible, and are significant in that they can alter residue polarity as well as conformations of peptide chains. These sulfur-based reactions are able to switch molecular and macromolecular properties of peptides and proteins in living systems and recently have been applied to synthetic peptide materials. Naturally occurring “sulfur switches” can be reversible or irreversible and are often triggered by enzymatic activity. Sulfur switches in peptide materials can also be triggered in vitro using oxidation/reduction and alkylation as well as photochemical reactions. The application of sulfur switches to peptide materials has greatly expanded the scope of these switches due to the ability to readily incorporate a wide variety of noncanonical sulfur-containing synthetic amino acids.Sulfur switches have been shown to provide considerable potential to reversibly alter peptide material properties under mild physiologically relevant conditions. An important molecular feature of sulfur-containing amino acid residues was found to be the location of sulfur atoms in the side chains. The variation of sulfur atom positions from the backbone by single bond lengths was found to significantly affect polypeptide chain conformations upon oxidation–reduction or alkylation/dealkylation reactions. With the successful adaptation of sulfur switches to peptide materials, future studies can explore how these switches affect how these materials interact with biological systems. This Account provides an overview of the different types of sulfur switch reactions found in biology and their properties and the elaboration of these switches in synthetic systems with a focus on recent developments and applications of reversible sulfur switches in peptide materials.

  PublisherOA PDFDOI

• Switchable Coacervate Formation via Amino Acid Functionalization of Poly(dehydroalanine)

  Biomacromolecules · 2024-03-01 · 3 citations

  articleOpen accessSenior authorCorresponding

  Our group recently developed a family of side-chain amino acid-functionalized poly(S-alkyl-l-homocysteines), Xaa-CH (Xaa = generic amino acid), which possess the ability to form environmentally responsive coacervates in water. In an effort to further study how the molecular structure affects polypeptide coacervate formation, we prepared side-chain amino acid-functionalized poly(S-alkyl-rac-cysteines), Xaa-rac-C, via post-polymerization modification of poly(dehydroalanine), ADH. The use of the ADH platform allowed straightforward synthesis of a diverse range of side-chain amino acid-functionalized polypeptides via direct reaction of unprotected l-amino acid 2-mercaptoethylamides with ADH. Despite their differences in the main-chain structure, we found that Xaa-rac-C can form coacervates with properties similar to those seen with Xaa-CH. These results suggest that the incorporation of side-chain amino acids onto polypeptides may be a way to generally favor coacervation. The incorporation of l-methionine in Met-rac-C allowed the preparation of coacervates with improved stability against high ionic strength media. Further, the presence of additional thioether groups in Met-rac-C resulted in an increased solubility change upon oxidation allowing facile reversible redox switching of coacervate formation in aqueous media.

  PublisherOA PDFDOI

• The Surfactant Properties of Clindamycin as a Useful Adjunct for Removing Ruptured Silicone Implants

  Plastic & Reconstructive Surgery Global Open · 2024-09-01

  articleOpen access

  Background: Silicone gel removal after breast implant rupture is a difficult task. Silicone is hydrophobic and thus cannot be irrigated effectively with saline. Attempts at mechanical removal with sponges are often partially successful. Incomplete removal results in persistent silicone contamination with possible local inflammation, infection, and silicone granulomata. In this partially quantitative investigation, we assess the de-adhesion ability of different clindamycin formulations against known surfactant controls when combined with silicone gel. Methods: To demonstrate surfactant properties in vitro, clindamycin phosphate, clindamycin hydrochloride, and a known surfactant, sodium dodecyl sulfate (SDS), were compared. An amount of 170 g of silicone gel placed in a dry glass container exhibited strong adherence to the container walls. In separate trials, clindamycin phosphate (300 mg in 100 mL), clindamycin HCl (300 mg in 100 mL), and SDS (1 g in 100 mL) solutions with normal saline were added to the silicone aggregate, and de-adhesion properties were compared. Results: All solutions aided in the de-adhesion of the sticky silicone from glass substrate. The SDS had the strongest effect, followed by clindamycin phosphate and then clindamycin HCl. The observed interactions suggested that all of the solutions behaved as ionic surfactant coating the silicone with negative charges via adsorption. However, the phosphate anionic formulation was associated with a greater surfactant effect than HCl. Conclusions: Clindamycin acts as a surfactant to aid in the clinical removal of ruptured silicone gel. Clindamycin phosphate seems to have a stronger effect than clindamycin HCl, likely related to the negative charges on the phosphate groups.

  PublisherDOI

• Influence of Side-Chain Molecular Features on Aqueous Coacervation of Multifunctional Homopolypeptides

  Polymer science & technology. · 2024-10-23 · 11 citations

  articleOpen accessSenior authorCorresponding

  Three different series of amino acid side-chain functionalized homopolypeptides were prepared as variants of previously reported α-helical, coacervate-forming cationic polypeptides. Studies of the physical behavior of these polypeptides in aqueous media in the presence of multivalent counterions enabled a better understanding of the molecular requirements for coacervate formation of side-chain functionalized homopolypeptides. Variation in lengths of side-chain amino acid or linker segments in cationic α-helical polypeptides was found either to prohibit coacervate formation or to allow adjustment of the phase transition temperature. A series of charge-reversed, anionic amino acid side-chain functionalized homopolypeptides were also prepared and found to be α-helical and able to form coacervates similar to analogous cationic homopolypeptides. These results illustrate the ability to predictably tune coacervation properties via molecular adjustment of side-chains in homopolypeptides and show that amino acid side-chain functionalized homopolypeptides can be used as a general platform for development of biomimetic, coacervate-forming polymers.

  PublisherDOI

• Preparation and stability of pegylated poly(S-alkyl-L-homocysteine) coacervate core micelles in aqueous media

  The European Physical Journal E · 2023-09-01 · 2 citations

  articleOpen accessSenior author
  PublisherOA PDFDOI

Recent grants

• Synthesis and Properties of Glycopolypeptide Biohybrid Materials

  NSF · $318k · 2010–2014

• New Initiators for Stereochemical Control in Polypeptide Synthesis

  NSF · $360k · 2004–2008

• Multifunctional methionine based materials for therapeutic use

  NSF · $436k · 2013–2016

• Development of Multifunctional Polypeptide Amphiphiles as Drug Delivery Vehicles

  NSF · $450k · 2009–2013

• Coacervate formation in amino acid functionalized polypeptides

  NSF · $457k · 2018–2022

Frequent coauthors

• Darrin J. Pochan

  University of Delaware

  63 shared

• Andrew P. Nowak

  HRL Laboratories (United States)

  41 shared

• Eric P. Holowka

  Wilmington University

  24 shared

• Daniel T. Kamei

  University of California, Los Angeles

  24 shared

• Michael V. Sofroniew

  University of California, Los Angeles

  22 shared

• Lisa Pakstis

  National Institute of Standards and Technology

  21 shared

• Galen D. Stucky

  University of California, Santa Barbara

  21 shared

• April R. Rodriguez

  HRL Laboratories (United States)

  19 shared

Education

• PhD, Chemistry

  University of California Berkeley

  1993

• BS, Chemistry

  University of California Irvine

  1989

Awards & honors

• Initiative of Excellence Visiting Faculty Scholar, Universit…
• Fulbright Scholar – Fulbright-Toqueville Distinguished Chair…
• Fellow of the American Institute for Medical and Biological…
• Herbert Newby McCoy Award (UCLA Dept. of Chem. & Biochem.) 2…
• IUPAC Macromolecular Division, Samsung-IUPAC Young Scientist…