Our research goal is to integrate fundamental research in novel macromolecular structure and polymerization processes with the development of high performance macromolecules for advanced technologies. Our research platforms focus on the design, performance, and societal implications of novel biomaterials for the following global impact: (1) gene/drug delivery, (2) tissue regeneration, and (3) biomedical devices.  Our hypothesis states that biomaterial design involves fundamental and common structural parameters for performance and that the integration of biomaterials in various biological environments will involve common interfacial and performance challenges.

The development of efficient, nontoxic materials for the delivery of therapeutic nucleic acids and drugs is a fundamental and important problem in biotechnology research.  For example, while many drugs are available to control cardiovascular disease (a leading global health problem), drug toxicity and lack of specificity leads to serious side effects.  Delivery vehicles have the potential to minimize side effects while maximizing medicinal efficacy, yet fundamental studies on biomaterials-based delivery systems are severely lacking.  Our research team focuses on the development and study of water-soluble polycations, particularly segmented block copolymer structures, for the binding, encapsulation, and delivery of anionic drugs and nucleic acids into cultured cells. We are currently examining structure-property effects of incorporating different cationic groups into these structures such as histidine-mimics and quaternary ammonium and phosphonium groups, and investigate the influence of nucleobase substitution in vector design, which may lead to novel binding strategies.

The tissue regeneration biotechnology seeks to replace failing organs, as opposed to treating the symptoms of underlying disease, functional restoration, improving quality of life. Our research builds on the discovery in the Long laboratories to fabricate nanometer-scale scaffolds based on nature-derived phospholipids and new families of photo-reactive amphiphiles.

Novel biomaterials that can transform the functionality and efficacy of medical devices and offer sustainable treatments with reduced cost are sought throughout the world to improve the quality of life. Recent efforts in our laboratories are focused on biomaterials for stents for sensing force needed to employ a device and also the incidence of tissue re-growth near the device interface with biological structure (Vlachos, Long) and biomaterial alternatives to acid-generation during polylactide absorption. Research efforts are proposed based on the synthesis and characterization of charged polyurethanes for subsequent performance as an elastomeric electromechanical transducer. 

In addition to macromolecular chemistry and engineering at the interface with biology, our research group also addresses fundamental questions involving ionic liquids, charged polymers for electroactive devices, fuel cell membranes, novel adhesives, block copolymer elastomers, high impact engineering thermoplastics, and responsive polymer compositions based on tailored hydrogen bonding and electrostatic interactions.  Recent efforts in self-healing compositions offer promise for novel families of cationic polymers.

1. Das, S.; Goff, J. D.; Williams, S.; Salas-de la Cruz, D.; Riffle, J. S.; Long, T. E.; Winey, K. I.; Wilkes, G. L., Synthesis and Characterization of Novel Segmented Polyionenes Based on Polydimethylsiloxane Soft Segments. Journal of Macromolecular Science Part A: Pure and Applied Chemistry 2010, 47 (3), 215-224.
2. Williams, S. R.; Salas-de la Cruz, D.; Winey, K. I.; Long, T. E.; Ionene segmented block copolymers containing imidazolium cations: Structure-property relationships as a function of hard segment content. Polymer 2010, 51 (6), 1252-1257.
3. Brown, R. H.; Duncan, A. J.; Choi, J.; Park, J. K.; Wu, T.; Leo, D. J.; Winey, K. I.; Moore, R. B.; Long, T. E., Effect of Ionic Liquid on Mechanical Properties and Morphology of Zwitterionic Copolymer Membranes. Macromolecules 2010, 43 (2), 790-796.
4. Cashion, M. P.; Li, X.; Geng, Y.; Hunley, M. T.; Long, T. E., Gemini Surfactant Electrospun Membranes. Langmuir 2010, 26 (2), 678-683.
   Brown, R. H.; Duncan, A. J.; Choi, J.; Park, J. K.; Wu, T.; Leo, D. J.; Winey, K. I.; Moore, R. B.; Long, T. E., Effect of ionic liquid on mechanical properties and morphology of zwitterionic copolymer membranes, Macromolecules 2010, 43(2), 790-796.
5. Lu, X.; Long, T. E., o-Nitrophenyl Sulfoxides: Efficient Precursors for the Mild Preparation of Alkenes. Journal of Organic Chemistry 2010, 75 (1), 249-252.
6. Duncan, A. J.; Layman, J. M.; Cashion, M. P.; Leo, D. J.; Long, T. E., Oligomeric A(2) + B-3 synthesis of highly branched polysulfone ionomers: novel candidates for ionic polymer transducers. Polymer International 2010, 59 (1), 25-35.
7. Viswanathan, K.; Long, T. E.; Ward, T. C., Hydrogen Bonding between Adenine-Modified Surfaces and Terminal Thymine-Functionalized Polystyrene: Influence of the Surface Adenine Concentration on Polymer Recognition. Langmuir 2009, 25(12), 6808-6812.