Our research program is focused on designing polymeric biomaterials and bioinspired materials. Our current focus areas are smart polymers for gene delivery; polymers for vaccine delivery; bioinspired nanocomposites; nanoparticles for co-localization of multiple enzymes; and neural tissue engineering and control of stem cell differentiation. Smart Polymers for Gene Delivery We have designed and synthesized novel smart bioinspired multi-block copolymers that exhibit pH and temperature sensitivity. These polymers are cationic and undergo thermoreversible gelation at body temperatures These cationic polymers exhibit complexation with DNA and serve as excellent injectable controlled gene delivery vectors for cancer therapies. These polymers can be used as injectable sustained gene delivery. These copolymers also exhibit selective transfection in cancer cells. Polymers for Vaccine Delivery This new project focuses on developing sustained vaccine delivery devices for single-dose vaccines. We have attached carbohydrate targeting moieties to our smart copolymeric nanoscale delivery systems for targeted delivery of protein and DNA vaccines. The block copolymers act as effective adjuvants to stimulate both immune pathways. Bioinspired Nanocomposites This multi-investigator project focuses on growing magnetic nanocrystals using our hierarchically self-assembled polymers described above, using aptamers and mineralization proteins. This approach aims to recreate the structure of magnetite nanocrystals embedded in organic tissue seen in many different living species, that confers super-paramagnetic properties. The combination of the mechanical properties of the polymer with the strong magnetic response of the magnetite offers new materials properties. Nanoparticles for Co-localization of Multiple Enzymes We are using a combination of self-assembling polymers that form micelles and biodegradable polyanhydride nanoparticles to serve as co-localization substrates for multiple enzymes. Co-localization of these enzymes is very important because of the reactive intermediates in the reactions involving multi-enzyme complexes. Neural Tissue Engineering and Control of Stem Cell Differentiation Our approach involves utilizing a combination of physical, chemical, biological and electrical cues on polymer substrates to enhance guided nerve regeneration and control adult stem cell differentiation. Our recent work has showed that physical cues in the form of micropatterned substrates, in synergy with other cues such as electrical, preferentially cause rat adult neural stem cells to adopt a neuronal fate as opposed to cells grown on smooth substrates.