Stanford Advisors


All Publications


  • Reactive oxygen species and enzyme dual-responsive biocompatible drug delivery system for targeted tumor therapy. Journal of controlled release : official journal of the Controlled Release Society Zhao, N., Ding, B., Zhang, Y., Klockow, J. L., Lau, K., Chin, F. T., Cheng, Z., Liu, H. 2020

    Abstract

    Spurred by newly developed drug delivery systems (DDSs), side effects of cancer chemotherapy could be reduced by using multifunctional nanoplatforms. However, the facile synthesis of effective DDSs remains a challenge. Here, a six-arginine-tailed anti-epidermal growth factor receptor (EGFR) affibody was employed to easily synthesize the highly reactive oxygen species (hROS)- and trypsin-responsive 11-mercaptoundecanoic acid-modified gold nanoclusters (MUA-Au NCs) for tumor-targeted drug delivery. The polyarginine moiety of affibody sealed methotrexate (MTX)-loaded MUA-Au NCs through charge effect, as well as leaving the rest targeting fragment of the affibody to specifically bind tumor overexpressed EGFR. As the shell of MUA-Au NCs-MTX-Affibody (MAMA), polyarginine chains of affibody could be digested by trypsin, helping to release MTX from MAMA. The released MTX accelerated destroying MUA-Au NCs through inducing the generation of hROS. Specifically targeting EGFR-overexpressed tumors, quickly delivering a sufficient amount of drug to the tumor, subsequently increasing the local MTX and hROS levels, and safely eliminating the biocompatible structure from kidney, endowed MAMA greater treatment effectiveness and lower side effect than chemotherapy, especially in pancreatic cancer due to its high trypsin level. This simply fabricated DDS may find applications in high effective cancer therapy, especially for tumors with high trypsin activity.

    View details for DOI 10.1016/j.jconrel.2020.05.031

    View details for PubMedID 32450093

  • An Activatable NIR Fluorescent Rosol for Selectively Imaging Nitroreductase Activity. Sensors and actuators. B, Chemical Klockow, J. L., Hettie, K. S., LaGory, E. L., Moon, E. J., Giaccia, A. J., Graves, E. E., Chin, F. T. 2020; 306

    Abstract

    Hypoxia (pO2 ≤ ~1.5%) is an important characteristic of tumor microenvironments that directly correlates with resistance against first-line therapies and tumor proliferation/infiltration. The ability to accurately identify hypoxic tumor cells/tissue could afford tailored therapeutic regimens for personalized treatment, development of more-effective therapies, and discerning the mechanisms underlying disease progression. Fluorogenic constructs identifying aforesaid cells/tissue operate by targeting the bioreductive activity of primarily nitroreductases (NTRs), but collectively present photophysical and/or physicochemical shortcomings that could limit effectiveness. To overcome these limitations, we present the rational design, development, and evaluation of the first activatable ultracompact xanthene core-based molecular probe (NO 2 -Rosol) for selectively imaging NTR activity that affords an "OFF-ON" near-infrared (NIR) fluorescence response (> 700 nm) alongside a remarkable Stokes shift (> 150 nm) via NTR activity-facilitated modulation to its energetics whose resultant interplay discontinues an intramolecular d-PET fluorescence-quenching mechanism transpiring between directly-linked electronically-uncoupled π-systems comprising its components. DFT calculations guided selection of a suitable fluorogenic scaffold and nitroaromatic moiety candidate that when adjoined could (i) afford such photophysical response upon bioreduction by upregulated NTR activity in hypoxic tumor cells/tissue and (ii) employ a retention mechanism strategy that capitalizes on an inherent physical property of the NIR fluorogenic scaffold for achieving signal amplification. NO 2 -Rosol demonstrated 705 nm NIR fluorescence emission and 157 nm Stokes shift, selectivity for NTR over relevant bioanalytes, and a 28-/12-fold fluorescence enhancement in solution and between cells cultured under different oxic conditions, respectively. In establishing feasibility for NO 2 -Rosol to provide favorable contrast levels in solutio/vitro, we anticipate NO 2 -Rosol doing so in preclinical studies.

    View details for DOI 10.1016/j.snb.2019.127446

    View details for PubMedID 32265579

    View details for PubMedCentralID PMC7138224

  • Carbon-11 labeled BLZ945 as PET tracer for Colony Stimulating Factor 1 Receptor imaging in the brain van der Wildt, B., Miao, Z., Park, J., Reyes, S., Klockow, J., Shen, B., Chin, F. WILEY. 2019: S487–S488
  • Near-Infrared Fluorescent Rosol Dye Tailored toward Lymphatic Mapping Applications ANALYTICAL CHEMISTRY Hettie, K. S., Klockow, J. L., Glass, T. E., Chin, F. T. 2019; 91 (4): 3110–17

    Abstract

    An optical molecular imaging contrast agent that is tailored toward lymphatic mapping techniques implementing near-infrared (NIR) fluorescence image-guided navigation in the planning and surgical treatment of cancers would significantly aid in enabling the real-time visualization of the potential metastatic tumor-draining lymph node(s) for their needed surgical biopsy and/or removal, thereby ensuring unmissed disease to prevent recurrence and improve patient survival rates. Here, the development of the first NIR fluorescent rosol dye (THQ-Rosol) tailored to overcome the limitations arising from the suboptimal properties of the generic molecular fluorescent dyes commonly used for such applications is described. In developing THQ-Rosol, we prepared a progressive series of torsionally restrictive N-substituted non-NIR fluorescent rosol dyes based on density functional theory (DFT) calculations, wherein we discerned high correlations amongst their calculated energetics, modeled N-C3' torsion angles, and evaluated properties. We leveraged these strong relationships to rationally design THQ-Rosol, wherein DFT calculations inspired an innovative approach and synthetic strategy to afford an uncharged xanthene core-based scaffold/molecular platform with an aptly elevated p Ka value alongside NIR fluorescence emission (ca.700-900 nm). THQ-Rosol exhibited 710 nm NIR fluorescence emission, a 160 nm Stokes shift, robust photostability, and an aptly elevated p Ka value (5.85) for affording pH-insensitivity and optimal contrast upon designed use. We demonstrated the efficacy of THQ-Rosol for lymphatic mapping with in vitro and in vivo studies, wherein it revealed timely tumor drainage and afforded definitive lymph node visualization upon its administration and accumulation. THQ-Rosol serves as a proof-of-concept for the effective tailoring of an uncharged xanthene core-based scaffold/molecular platform toward a specific imaging application using rational design.

    View details for PubMedID 30669835

  • Theranostic nanoparticles enhance the response of glioblastomas to radiation Nanotheranostics Wu, W., Klockow, J. L., Mohanty, S., Ku, K. S., Daldrup-Link, H. E. 2019; 3(4) (299-310)

    View details for DOI 10.7150/ntno.35342

  • A novel theranostic strategy for MMP-14 expressing glioblastomas impacts survival Mohanty, S., Chen, Z., Li, K., Morais, G., Klockow, J., Yerneni, K., Pisani, L., Chin, F., Mitra, S., Cheshier, S., Chang, E., Gambhir, S., Rao, J., Loadman, P. M., Falconer, R. A., Daldrup-Link, H. E. AMER ASSOC CANCER RESEARCH. 2018
  • Imaging hypoxia: Development of a PET-optical smart probe Klockow, J. L., Hettie, K. S., Chin, F. T. AMER ASSOC CANCER RESEARCH. 2018
  • A novel theranostic strategy for MMP-14 expressing glioblastomas impacts survival. Molecular cancer therapeutics Mohanty, S., Chen, Z., Li, K., Morais, G. R., Klockow, J., Yerneni, K., Pisani, L., Chin, F. T., Mitra, S., Cheshier, S., Chang, E., Gambhir, S. S., Rao, J., Loadman, P. M., Falconer, R. A., Daldrup-Link, H. E. 2017

    Abstract

    Glioblastoma (GBM) has a dismal prognosis. Evidence from preclinical tumor models and human trials indicates the role of GBM initiating cells (GIC) in GBM drug resistance. Here, we propose a new treatment option with tumor enzyme-activatable, combined therapeutic and diagnostic (theranostic) nanoparticles, which caused specific toxicity against GBM tumor cells and GICs. The theranostic cross-linked iron oxide nanoparticles (CLIO) were conjugated to a highly potent vascular disrupting agent (ICT) and secured with a matrix-metalloproteinase (MMP-14) cleavable peptide. Treatment with CLIO-ICT disrupted tumor vasculature of MMP-14 expressing GBM, induced GIC apoptosis and significantly impaired tumor growth. In addition, the iron core of CLIO-ICT enabled in vivo drug tracking with MR imaging. Treatment with CLIO-ICT plus temozolomide achieved tumor remission and significantly increased survival of human GBM bearing mice by more than 2 fold compared to treatment with temozolomide alone. Thus, we present a novel therapeutic strategy with significant impact on survival and great potential for clinical translation.

    View details for PubMedID 28659432