Advanced Polymeric and Bionanocomposite Solutions for Tissue Engineering and Drug Delivery Applications

Research Interests:

The rapidly evolving toolset available to polymer scientists is enabling the birth of a new generation of smart composite devices which can be tailored to suit the specific and demanding requirements of advanced biomaterials applications from efficient and site-specific drug delivery to the regeneration of complex tissue. With a strong background in polymer synthesis, characterization, and transport phenomena and development of polymeric therapies for tissue engineering applications, I am well-positioned to push the boundaries of scientific discovery at the interface of polymer science and biomedical research. Within this broad scope, early efforts will focus on three primary research thrusts:

I)    Injectable In Situ Forming Hydrogels for Tissue Engineering and Drug Delivery

II)   Bionanocomposite Polymers for Drug Delivery and Imaging

III)  3-Dimensional Bioprinted Composite Scaffolds for Tissue Engineering

Background:

My doctoral research focused on observing and comprehending the transport of small penetrant molecules in glassy polymers and elucidating the effects of structure and network parameters on the transport mechanism, with a particular emphasis on the occurrence of non-Fickian transport dynamics. Novel structure property relationships were developed for penetrant transport dynamics in the Case II transport regime, material-based mechanisms for controlling the nature of penetrant transport in glassy polymers were elucidated, and high-resolution X-ray computed tomography was adapted as a novel technique for quantitative, in situ imaging of penetrant transport processes.

In my post-doctoral studies, I have moved to the interface of polymer science and biomedical research, focusing on the design and application of injectable hydrogel-cell composite scaffolds for tissue regeneration in craniofacial defects. Specifically, we have developed and filed a provisional patent on a novel class of two-component, in situ dual-hardening hydrogels combining near-instantaneous temperature-induced gelation with epoxy-based crosslinking utilizing degradable polyamidoamine macromers. Such in situ dual-hardening, dimensionally stable, defect-filling, and degradable hydrogels with high gel water content are attractive substrates for tissue engineering and cellular delivery applications. In particular, the use of water-soluble and degradable polyamidoamine polyaddition-formed macromers offers tremendous synthetic flexibility and control over subsequent gel properties.

Post-doctoral Advisor:  Professor Antonios G. Mikos, Departments of Bioengineering and Chemical and Biomolecular Engineering, Rice University

Ph.D. Advisor:  Professor Nicholas A. Peppas, Departments of Chemical and Biomedical Engineering, The University of Texas at Austin

Publications:

1. A.K. Ekenseair, F.K. Kasper and A.G. Mikos. “Perspectives on the Interface of Drug Delivery and Tissue Engineering.” Adv. Drug Delivery Rev. (in preparation).
2. A.K. Ekenseair, K.W.M. Boere, S.N. Tzouanas, T.N. Vo, F.K. Kasper and A.G. Mikos. “Structure-Property Evaluation of Thermally and Chemically Gelling Injectable Hydrogels for Tissue Engineering.”  Biomacromolecules (submitted).
3. A.K. Ekenseair, R.N. Seidel and N.A. Peppas. “Tuning the Transport Dynamics of Small Penetrant Molecules in Glassy Polymers.” Polymer (submitted).
4. A.K. Ekenseair, K.W.M. Boere, S.N. Tzouanas, T.N. Vo, F.K. Kasper and A.G. Mikos. “Synthesis and Characterization of Thermally and Chemically Gelling Injectable Hydrogels for Tissue Engineering.” Biomacromolecules, (in press), DOI: 10.1021/bm300429e.
5. A.K. Ekenseair and N.A. Peppas. “Network Structure and Methanol Transport Dynamics in Poly(methyl methacrylate).” AIChE J., 58(5): 1600-1609 (2012).
6. A.K. Ekenseair, R.A. Ketcham and N.A. Peppas. “Visualization of Anomalous Penetrant Transport in Glassy Poly(methyl methacrylate) Utilizing High-Resolution X-ray Computed Tomography.” Polymer, 53(3): 776-781 (2011).
7. A.K. Ekenseair, L. Duan, D.J. Carrier, D.I. Bransby and E.C. Clausen. “Extraction of Hyperoside and Quercitrin from Mimosa (Albizia julibrissin) Foliage.” Appl. Biochem. Biotechnol., 129-132 : 382-91 (2006).