Research
‘BUNDLEMER’ BUILDING BLOCKS FOR THE CONSTRUCTION OF NEW PEPTIDE MATERIALS
With the design of individual coiled coils, one can create a material building block with the desired, specific display of side chain chemistry in the interior or on the surface of the building block particle. Therefore, one can design hierarchical assembly pathways using physical and covalent interactions to produce desired nanostructures. Current efforts involve rigid rod polymers, porous nanomaterials, nanomachines, hydrogels, as well as fibers and films. All final materials have the opportunity to be sustainable and environmentally compatible due to the amino acid nature of the molecular building blocks.
![](https://sites.udel.edu/pochangroup/files/2022/08/Screenshot-2022-08-08-131727-1024x747.png)
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BIOPOLYMER NANOCOMPOSITES
The addition of small amounts of clay platelet filler, carbon nanotubes, or glass microfibers to a polymer matrix greatly enhances many chemical and mechanical material properties of the matrix polymer. This well-developed area of materials science and engineering is producing new materials in diverse areas such as engineering thermoplastics and robust polymer-based batteries. Our interest in nanocomposites is to produce strong, robust materials using biopolymers as the matrix material and using various biomolecular assemblies (e.g., nanofibrillar peptide assemblies) as the reinforcement phase. Strong, stiff materials can then be produced with inherent sustainability and bioproperties (biocompatibility, biodegradability, environmental compatibility, antimicrobial) due to the completely biomolecular nature of the material.
RESPONSIVE MATERIALS CONSTRUCTED VIA PEPTIDE FOLDING AND CONSEQENT SELF-ASSEMBLY
Oligopeptides are designed to intramolecularly fold in response to a desired environmental cue. After folding, self-assembly into a desired structure/material occurs. Importantly, by linking peptide folding with self-assembly , material formation is completely reversible providing for materials with properties responsive to the environment surrounding them. This interdisciplinary work involves peptide design through materials characterization. Examples of responsive materials are extremely dilute but rigid hydrogels completely reversible with pH and temperature.
![](https://sites.udel.edu/pochangroup/files/2022/08/2002-JACS-Responsive-Hydrogels-from-the-Intramolecular-Folding-and-Self-Assembly-of-a-Designed-Peptide.gif)
VESICLE AND MICELLE FORMATION VIA NON-IONIC, AMPHIPHILIC BLOCK COPOLYPEPTIDE SELF-ASSEMBLY
Amphiphilic block copolypeptides are designed with PEGylated, nonionic hydrophilic blocks and hydrophobic blocks with varying secondary structure. These molecules are robust membrane and micelle formers in aqueous solution. Molecular parameters (e.g. relative block length, block secondary structure) are chosen in an effort to design a priori a desired assembly shape and size. These designed assemblies hold promise in the areas of drug and cell delivery.
![](https://sites.udel.edu/pochangroup/files/2022/08/2015-Marcomolecules-Multigeometry-nanoparticles-hybrid-vesicle-cylinder-nanoparticles-constructed-with-block-copolymer-solution-assembly-and-kinetic-control-1.jpeg)
![](https://sites.udel.edu/pochangroup/files/2022/08/2007-Langmuir-Controlled-stacking-of-charged-block-copolymer-micelles-1.jpeg)