The quest for sustainable chemicals and materials to meet the demands of a rapidly rising global population while mitigating risks of increasing CO2emissions and associated climate change represents a grand challenge for humanity and motivates much of our work. We believe it is critical to focus our inventiveness on work that has the potential to revolutionize the way we synthesize next generation chemicals and materials. For this purpose, wecombine chemical and biocatalysts to develop efficient green routes to monomers, prepolymers, polymer synthesis and modification. We are also applying the same principles for the development of next-generation therapeutics including low molar mass drugs, matrices for tissue engineering and biodegradable polymers.  By using an expanding arsenal of biobased building blocks and enzymes to synthesize and modify polymeric materials, important environmental, economic and product performance benefits will result. This will be a direct outcome of milder reaction conditions that increase worker safety, higher reaction efficiencies, processes that require less discrete steps, the avoidance of heavy metals, and the ability to develop well defined functionalized polymeric materials. 

 

Examples of currently ongoing research is as follows. There is a need to develop efficient and scalable methods to synthesize peptides. These peptides hold great promise for use as building blocks that provide antimicrobial, metal binding, self-assembling, bioadhesives (replace sutures) and environmentally responsive properties. However, current methods to synthesize peptides that include solid and liquid phase peptide synthesis (SPPS and LPPS) are expensive which prohibits their use in these and other exciting applications.  Instead, peptides prepared by SPPS and LPPS are limited in fields of applications (primarily medical) do to their high costs.  Our laboratory is pioneering methods that enable the synthesis and scale-up of peptides for a wide range of exciting material applications. In other work, we are using the selectivity of lipase catalysts to synthesize functional bioresorbable polyesters that meet important needs for tissue engineering matrices, drug delivery systems and bioactive materials. Another focus area is to use bacteria that synthesize cellulose in the form of 3-D nano-matrices with controllable fiber and pore morphologies.  These nanomatrices in both native and modified forms are being used to create next-generation membranes for separations, water purification, as reservoirs for liquid crystals that create voltage regulated switchable windows and much more.  Our laboratory is also looking to nature for next-generation bioactive compounds (e.g. anticancer, antimicrobial, immune-modulators and insecticides) therapeutics. The search is currently focused on a class of glycolipids that we obtain by fermentation and then modify by chemical and enzymatic methods to enhance their biological activity.  We are also utilizing essential oils in various forms as renewable/safe pesticides, insecticides and tick repellents.  Some of these antimicrobial components are finding their way into a new family of films to protect fruits and vegetables. We are also developing other delivery forms that are needed for these natural bioactives. Problems associated with plastic waste and currently ineffective physical recycling methods has motivated our team to develop chemo-enzymatic processes for the conversion of waste plastics to valuable building blocks.  Work thus far has focused on a family of enzymes known as cutinases that degrade plastic water bottles made from PET to terephthalic acid and ethylene glycol. We do this work in close collaboration with physicists, biologists, biomedical engineers, entomologists, mechanical engineers and scientists from other disciplines.