In 1998, Prof. Gross joined the faculty of NYU-Poly as the Herman F. Mark Professor of Polymer Science. At that time, he established his laboratory for the study of Biocatalysis and Bioprocessing of Macromolecules. Research in the laboratory of Prof. Gross is focused on cell-free and whole-cell biotransformations. Chemists, biochemists, microbiologists, materials scientists, engineers, physicists and clinicians work in teams on projects ranging from enzymatic and chemo-enzymatic routes to monomers, prepolymers, polymers and bioactive molecules. Novel enzyme engineering techniques and methods for enzyme immobilization are used to develop efficient catalysts that function under practical conditions. From these studies our group is developing fundamental new knowledge in enzyme structure-activity relationships for polymer synthesis and degradation reactions as well as an understanding of critical design elements that stabilize and activate enzymes on surfaces and within macroporous resins.
Research Focus: Over the past ten years, Dr. Gross has focused on the following areas.
- Enzyme families: Lipases, cutinases, proteases, peroxidases, metallo-proteins, epoxidases, and epoxide hydrolases as catalysts for monomer/polymer synthesis and modification.
- Protein engineering: Engineering protease, lipase, cutinase, mono-oxgenase (P450), and metallo-proteins for polymer chemistries.
- Polyester synthesis: Immobilized enzyme-catalyzed condensation and ring-opening polymerizations.
- Monomers: Vinyl monomers by selective acylation of natural building blocks (e.g. carbohydrates, amino acids and lipids).
- Prepolymers: Linear and branched polymers from polyols and other multifunctional building blocks.
- Oligopeptides: Oligopeptides by protease catalysis with controlled sequence to develop bioactive and functional materials.
- Lipid bio-oxidation: Bio-oxidation of lipids to produce new functional lipid-based materials.
- Enzyme triggered chemical events: Mild ‘triggered’ enzyme-catalyzed crosslinking and degradation reactions.
- Silicone based materials: Mild enzyme-catalyzed routes to silicone-sugar conjugates, silicone-polyester and polyamide block copolymers, and silicone prepolymers.
- Bioresorbable polymers: Functional bioresorbable polymers for drug delivery and tissue-engineering scaffolds.
- Polymer modification: Controlled and selective modification of polymers and surfaces.
- Enzyme immobilization: Design, synthesis, analysis and optimization of systems for enzyme immobilization.
- Biosurfactants: Synthesis of bio-derived low and high molar mass surfactants.
- Biopharmaceuticals: Elucidating structure-activity relationships for uses of glycolipids as therapeutics (septic shock, asthma, anti-cancer) and natural antimicrobial agents.
The laboratory is also investigating novel ways that enzymes can be used to modify polymers. Cutinases are the major enzyme family under study for polymer modification. They are showing extraordinary activity for hydrolysis of rigid surfaces such as polyethylene terephthalate (PET). Their potential to do various surface chemistries as well as their ability to remove various components from surfaces such as fibers and processed articles is under study.
Our laboratory is working with DNA 2.0, a privately-owned genetic engineering company, to refine and test computational enzyme engineering tools. Altering a polyeptide’s function by changing the sequence allows natural proteins to be converted into useful molecular tools. The goal is to use these methods to redesign enzymes for monomer and polymer enzyme-catalyzed biotransformations.
Polymer families under study:
- Bioresorbable polyesters, polycarbonates and polyurethanes
- Prepolymers
- Polyethylene-like polyesters from ω-hydroxy fatty acid building blocks.
- Oligopeptide macromers
- Microbial polyesters
- Microbial polyamides (e.g. γ-poly(glutamic acid) and ω-poly(lysine))
- Microbial polysaccharides
Surfactant research targets:
- Biobased surfactants from fatty acids and carbohydrate building blocks
- Amphiphilic oligopeptides
- Microbial Surfactants
- Biopesticides
Medical research targets:
- Bioresorbable polymers for drug delivery and use for structural/biologically active materials during wound-healing.
- Water-soluble polymers for drug targeting.
- Functional oligomers for drug delivering by in-situ crosslinking.
- Functional micro- and nano-particle drug delivery systems.
- Structure-activity relationships of microbial glycolipids. This work has focused on sophorolipids and structural analogs. Their activity for immunoregulation, antiviral and antimicrobial properties is under study.
- Mild crosslinking reactions that create hydrogels for cell entrapment, growth and differentiation.