The Srivalleesha Mallidi Lab


Science & Technology Center 213

Molecular Specific Photoacoustic Imaging with Targeted Nanoparticles

Assessment of molecular signatures of tumors in addition to their anatomy and morphology is desired for effective diagnostic and therapeutic procedures. Development of in vivo imaging techniques that can identify and monitor molecular composition of tumors remains an important challenge in pre-clinical research and medical practice. My graduate work involved development of a molecular photoacoustic imaging technique that can visualize the presence and activity of one or more important cancer biomarkers utilizing the effect of plasmon resonance coupling between molecular targeted gold nanoparticles. For example, our very highly cited paper published in Nanoletters showed Epidermal Growth Factor Receptor (EGFR) activity using spectral analysis of photoacoustic images revealed profound changes in the optical absorption of systemically delivered EGFR-targeted gold nanospheres due to their molecular interactions with tumor cells overexpressing EGFR. Ultrasound-guided molecular photoacoustic imaging can potentially aid in tumor diagnosis, selection of customized patient-specific treatment, and monitor the therapeutic progression and outcome in vivo.

Photoacoustic Imaging Guided Therapy

Currently our research focuses on image-guided light based therapies such as photothermal therapy, photodynamic therapy (PDT, a photochemistry based cytotoxic therapy), vascular targeted chemotherapy, and related therapeutic combinations for pancreatic, brain and skin cancers guided using functional information obtained from ultrasound and photoacoustic imaging techniques Primary parameters such as tumor viability and necrotic volumes, vasculature, perfusion, blood oxygen saturation, and glucose metabolism will be measured and the status of these parameters pre-therapy and changes in the parameters post-therapy will be utilized to design (e.g., dose and sequence) and monitor (predict efficacy) therapeutic strategies. Recent work in this topic has been selected as Cover Feature in the Theranostics Journal.