Department Faculty

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Timothy C. Johnstone
  • Title
    • Assistant Professor
  • Division Physical & Biological Sciences Division
  • Department
    • Chemistry & Biochemistry Department
  • Phone
    831-459-3216 (Office), 831-459-4964 (Lab)
  • Email
  • Website
  • Office Location
    • Physical Sciences Building, 248
    • Physical Sciences Bldg 248 (Office)
    • Physical Sciences Bldg 153 (Lab)
  • Mail Stop Chemistry
  • Mailing Address
    • 1156 High St, PSB 248
    • Santa Cruz CA 95064-1077

Summary of Expertise

Medicinal bioinorganic chemistry; synthetic inorganic chemistry; nanoparticle drug delivery; inorganic spectroscopy; small-molecule X-ray crystallography; mammalian and microbiological cell culture

Research Interests

The group studies the chemistry and reactivity of inorganic compounds to solve important problems in the arena of human health. Current topics of investigation include: developing an antidote for carbon monoxide poisoning; investigating biopolymers as a means of nanoformulating clinically-approved antimony-based drugs used to treat leishmaniasis; utilizing novel non-covalent interactions to sequester phosphate; developing targeted polymeric nanoparticles loaded with arsenic-based anticancer agents

Carbon Monoxide Poisoning – Over 20,000 Americans visit emergency rooms for CO poisoning each year. The toxicity of CO arises in large part from its avidity for binding transition metals, such as the Fe in hemoglobin. Currently, the best option to treat an individual with CO poisoning is to place them in fresh air but, in the time it takes for CO to be fully cleared from the body, oxygen deprivation can result in severe injury and brain damage. By capitalizing on our fundamental understanding of the coordination chemistry of CO, we are designing transition metal complexes that can be used as antidotes to treat CO poisoning.

Pentavalent Antimonial Antileishmanials – Leishmaniasis is a neglected tropical disease that affects over 6 million people in close to 100 different countries. The disease is caused by infection with parasites from the Leishmania genus that are transmitted by insect vectors.  A mainstay treatment for the disease comprises a class of drugs known as the “pentavalent antimonials.” Despite having been used clinically for over a century, the structures of these molecules remain unknown. A range of physical techniques are being employed to uncover the structures of these compounds and we will use that molecular-level understanding to design antileishmanial nanoparticles. The nanodelivery strategy is being pursued to reduce the side effects that accompany treatment and decrease the number of treatments needed.

Arsenic-Delivering Anticancer Nanoparticles – Despite the common association of arsenic with toxicity, arsenic trioxide is approved by the FDA for the treatment of acute promyelocytic leukemia (APL). As with many cytotoxic anticancer drugs, however, off-target toxicity results in a range of side effects including nausea, vomiting, fatigue, fever, headaches, tachycardia, swelling, and peripheral neuropathy. Using the same strategies as for the Sb(V)-delivering nanoparticles, arsenic will be encapsulated and targeting ligands installed on the surface of the nanoparticle to direct it to receptors specifically expressed on the surface of the cancer cells. This targeting strategy will be used to widen the scope of arsenic trioxide treatment.

Biography, Education and Training

B.Sc. Chemistry, McGill University (Montreal, QC)

Ph.D. Chemistry, Massachusetts Institute of Technology (Cambridge, MA), Prof. S. J. Lippard

Post-Doctoral Researcher, Massachusetts Institute of Technology (Cambridge, MA), Prof. E. M. Nolan

NSERC Post-Doctoral Fellow, University of Toronto (Toronto, ON), Prof. D. W. Stephan