Postdoctoral Fellow
Materials Science

PhD, Massachusetts Institute of Technology, 2002 (chemistry)
BS, University of California, Los Angeles, 1997 (chemistry)

Mailing Address:
Northwestern University
Materials Science & Engineering
2220 Campus Drive
Evanston, IL 60208-3108

Office Location:
Nanofab 3026

(847) 467-4928 office
(847) 491-3010 facsimile

Email J. D.

John D. Tovar

Academic Interests
Materials-oriented synthetic organic chemistry, electrochemistry, conjugated and conducting polymers, supramolecular chemistry, organic electronics.

Professional Experience
Postdoctoral Fellow, Northwestern University (S. I. Stupp, Materials Science and Engineering, 2002+)
Graduate Research Assistant, MIT (T. M. Swager, Chemistry,1998-2002)
Teaching Assistant, MIT Chemistry (1997-1998)
Undergraduate Research, UCLA; J. Glater, Civil Engineering (1995-1996); Y. Rubin, Chemistry (1996-1997)
Assistant Chemical Safety Officer, UCLA Environment, Health and Safety (1995-1997)

Research Project
Contemporary tissue engineering has a primary focus on passive, three-dimensional scaffolds designed to elicit cellular interactions or to promote adhesion and growth. Electrically active scaffolds could provide a means to controllably interface with biological environments yet they remain elusive. Nanometer-scale supramolecular electronic materials with specific binding sites will offer innovative new approaches for tissue repair and ultra-sensitive biological detection on well-defined biomimetic scaffolds. My postdoctoral work in the Stupp group seeks to incorporate organic functionality into peptide amphiphiles (PAs) with the goal of imparting electrical conductivity and biological recognition to the cylindrical nanostructures formed after self-assembly. We may employ these functional systems to study biological sensing and cellular proliferation on the nanoscale through external control of the scaffold’s electrical characteristics. These molecular constructs allow for rapid synthetic fine-tuning of the resulting self-assembled scaffolds at size regimes not currently obtainable through standard polymer processing techniques. To access these systems, we are using established chemical precedents to covalently incorporate electronically conductive, fluorescent or semiconductive functionality. Our molecular design will confer supramolecular fibers with the ability to promote biological interactions important for analyte sensing and tissue engineering applications (proteins, viruses, cells) and to detect such interactions through the supramolecular ensemble’s observable optoelectronic properties.

Any application of such nanomaterials will require rational manipulation and organization into devices. We have designed PAs that present supramolecular binding sites in order to promote organization onto suitably patterned surfaces prior to the pH-driven self-assembly that occurs from solution. This approach to device construction represents a significant step towards realizing well-ordered and robust biological nanocircuitry that does not require individual manipulation of the active elements. Key to this approach is learning how to electronically address a bioactive nanostructure as such hybrid devices will modulate current passing through the scaffold during sensing or cell proliferation. In appropriate device architectures, we can assess the optical and electrical properties inherent to the cylindrical nanostructure as well as measure real time alterations of conductivity, charge mobility or emission responses that may accompany molecular recognition events. By controlling neuronal repair at the nanoscale, this research stands to offer new biomaterials options in the quest for viable neuronal interconnects between damaged tissues. Fundamental questions concerning charge transport through self-assembled morphologies may remain unanswered without the development of rational synthetic approaches to functional nanostructures. The answers offer tremendous promise for the design of advanced biomedical scaffolds for sensing and repair.

PUBLICATIONS
[7] Tovar; Swager “Cofacially Constrained Organic Semiconductors” J. Polym. Sci. A, Polym. Chem. 2003, 41, 3693-3702.
[6] Tovar; Swager “Synthesis of Tuneable Electrochromic and Fluorescent Polymers” ACS Symp. Ser. No. 888 (2004), Ch. 29.
[5] Tovar; Rose; Swager “Functionalizable Polycyclic Aromatics Through Oxidative Cyclization of Pendant Thiophenes” J. Amer. Chem. Soc. 2002, 124, 7762-7769.
[4] Tovar; Swager “Exploiting the Versatility of Organometallic Cross-Coupling Reactions for Entry into Extended Aromatic Systems” J. Organomet. Chem. 2002, 653, 215-222.
[3] Tovar; Swager “Poly(naphthodithiophene)s: Robust, Conductive Electrochromics via Tandem Cyclization-Polymerizations” Adv. Mater. 2001, 13, 1775-1780.
[2] Tovar; Swager “Pyrylium Salts via Electrophilic Cyclization: Applications for Novel 3-Arylisoquinoline Syntheses” J. Org. Chem. 1999, 64, 6499-6504.
[1] Tovar; Jux; Jarrosson; Khan; Rubin “Synthesis and X-Ray Characterization of an Octaalkynyldibenzooctadehydro[12]annulene” J. Org. Chem. 1997, 62, 3432-3433.