University of Southern California

Research

Featured Research

2014

Bispecific hybrid nanoworms for immunotherapy of B-cell lymphoma
John Mackay jamackay@usc.edu,  Pharmacology and Pharmaceutical Sciences, USC School of Pharmacy
Alan Epstein, aepstein@usc.edu, Pathology, Keck School of Medicine
Zibo Li ,ziboli@usc.edu, Radiology, Keck School of Medicine
Peter Conti, pconti@usc.edu, Radiology, Pharmacy and Biomedical Engineering, Keck School of Medicine

About 66,000 US patients were diagnosed with lymphomas in 2011, out of which 65,000 had Non-Hodgkin’s lymphoma (NHL)11. NHL is characterized by increased production of malignant B-cells, which can be targeted through cell-surface CD19 or CD2012, 13. Antibodies against CD20 have been developed for NHL and are clinically successful. The most prominent example is rituximab, a chimeric antibody that targets malignant as well as normal Bcells2. Crosslinking of rituximab using a secondary antibody against the Fc region promotes cell apoptosis, which led to the observation that CD20-mediated apoptosis can be potentiated through strategies that induce multivalency4, 14. In combination with chemotherapy, immunotherapeutics overcome resistance in half of NHL patients3. More recently, bispecific antibodies, such as blinatumomab, that link targets on B-cell lymphomas (CD19, CD20) with effectors on cytotoxic T-cells (CD3) have entered a phase III clinical trial5. Phase II trials suggest that the bispecific antibody outperforms chimeric rituximab because it facilitates killing by T cells that interact with cancer of B cell lineage.

Nanoparticle Mediated Delivery Targeting TAK1 as a Metastatic Breast Cancer Therapy
Min Yu, minyu@usc.edu, Stem Cell Biology and Regenerative Medicine, Keck School of Medicine
Pin Wang, pinwang@usc.edu, Chemical Engineering and Materials Science, Viterbi School of Engineering
Julie Lang, Julie.lang@med.usc.edu, Surgery, Keck School of Medicine

In this multidisciplinary application among the Yu and Lang laboratories from the Norris Cancer Center and the Wang laboratory from Viterbi School of Engineering, we aim to test the hypothesis that the nanoparticle-packaged inhibitor to TAK1 can suppress metastatic breast cancer (MBC) formation in distant organs in a xenografted mouse model and such approach can improve our ability to treat MBC.

Optimization of pH-sensitive peptide nanoconstructs for use in targeting the mildly acidic tumor microenvironment Jennica Zaro, zaro@usc.edu, Pharmaceutical Sciences, USC School of Pharmacy Peter Conti, pconti@usc.edu, Radiology, Pharmacy and Biomedical Engineering, Keck School of Medicine

In this renewal application, we plan to investigate the toxicity, particularly in the kidney and liver, of these novel pH-sensitive nanoconstructs in order to evaluate their potential applicability in cancer diagnosis and therapy. Furthermore, several strategies to reduce the nonspecific accumulation of the constructs in the kidney and liver will also be tested. The pH-sensititve nanoconstructs consist of two different types of cell penetrating peptides (CPPs): an amphipathic peptide, Model Amphipathic Peptide, and a cationic ligoarginine peptide. A highly pHsensitive histidine-glutamic acid (HE) copolymer sequence is linked to the CPPs to prevent non-specific internalization of the construct in non-target cells, and to target internalization at the surface of the acidic (pH 6 – 7) tumor microenvironment. According to our recent studies, these constructs show high accumulation and retention near the tumor site in a xenograft breast cancer mouse model.

2013

Diagnostic Imaging of Smart Genetically Engineered Nanomedicines
John Mackay, jamackay@usc.edu, Pharmocology and Pharmaceutical Sciences, USC School of Pharmacy
Peter Conti, pconti@usc.edu, Radiology, Keck School of Medicine of USC
Zibo Li, ziboli@usc.edu, Radiology, Keck School of Medicine of USC

The incidence of breast cancer remains significant with nearly a quarter of a million new cases of invasive breast cancer diagnosed annually.1 While the survival rates of early stage breast cancer are relatively high, advanced disease results in nearly 40,000 deaths per year. As such it is the second most deadly cancer affecting American women.1 Chemotherapy for advanced disease has devastating side effects and is commonly prescribed without determining whether or not the patient is likely to respond. To address this limitation, this project explores the direct non-invasive imaging of the interaction of targeted drug carriers within individuals prior to the delivery of a chemotherapeutic formulation explored by our group. The ability to quantitatively predict the distribution and pharmacokinetics (PK) of chemotherapeutics for individual patients using a clinically-relevant imaging modality would give physicians more power to personalize therapy while avoiding treatment of patients who do not stand to benefit.

Therapeutic Nanoplatform Targeted to Bone Metastatic Cancers
Fabien Pinaud, pinaud@usc.edu, Biological Science, Dornsife College of Letters, Arts and Sciences
Charles McKenna, mckenna@usc.edu, Chemistry, USC Dornsife College of Letters, Arts and Sciences
Mitchell Gross, mitcheeg@med.usc.edu, Medicine and Urology, Keck School of Medicine

The novel therapeutic nanoplatform developed in this project will allow a highly specific treatment of cancer cells that have spread to the bone, while, at the same time, provide means to block further cell invasion at treated metastatic niches by slowing down bone resorption. In this respect, it will significantly improve and simplify the treatment of bone metastatic cancers by providing a single therapeutic agent with increased specificity compared to current chemotherapeutics without compromise on the palliative and preventive benefits of BPs for improved pain management and quality of life in cancer patients living with bone metastases.

Developing SUPR Peptide Diagnostics and Therapeutics for Oral Cavity Carcinomas
Richard Roberts, richrob@usc.edu, Chemistry, Chemical Engineering, Biology, USC Dornsife College of Letters, Arts and Sciences
Uttam Sinha, Sinha@med.usc.edu, Department of Otolaryngology, Head and Neck Surgery, Keck School of Medicine of USC

The purpose of this project is to develop new molecular agents (SUPR Peptides) that will assist in diagnosis and treatment of head and neck cancers—squamous cell carcinoma of the of the head and neck (SCCHN). Risk factors for developing SCCHN include drinking, smoking/tobacco use, and Human papillomavirus (HPV). Early detection is essential for improving outcomes, especially for high-risk groups. This project will aim at three critical targets—the IL-6 and IL-8 proteins and the human papillomavirus (HPV).

2012

Targeting the Mildly Acidic Tumor Microenvironment using pH-sensitive Recombinant Peptide Nanoconstructs
Jennica Zaro zaro@usc.edu, Pharmacy
Peter Conti conti@usc.edu, Radiology

This project focuses on the recombinant production and characterization of highly pH sensitive oligopeptidyl nano constructs designed for the selective and efficient targeting toward the acidic microenvironment of tumor cells. Although the acidic tumor microenvironment (pH 6.5 – 7) is well-established (1), it has not been fully exploited in either diagnosis or therapeutic targeting mainly due to the difficulty of achieving (i) chemical activation in this weakly acidic range and (ii) a sufficient depth of tumor penetration. We are testing the feasibility of using our newly designed pH-sensitive nano constructs as a novel diagnostic tool in cancer therapy. We anticipate that the critical experiments will lead to the identification of an optimal nanoconstruct for tumor imaging and/or targeted delivery.

Targeted Nanoparticle Therapy for Ewing’s Sarcoma
Timothy Triche triche@usc.edu, Pediatrics
Richard Roberts richrob@usc.edu, Chemistry

This project is synthesizing and validating nanoparticles suitable for delivery of small molecules.
We aim to synthesize hybrid polymerized liposomal nanoparticle (PLNs) of uniform size with surface modifications that render them extremely biocompatible, non-immunogenic, and amenable to cellular binding and uptake, suitable for drug delivery.

In addition, we are targeting nanoparticles to tumor cells with CD99 specific peptides. We seek to target these HPLNs to tumor cells while sparing normal tissue, using a novel surface affinity reagent developed at USC by Prof. Roberts. We propose to develop a unique targeting technology based on a human peptides that bind CD99. This technology uses rapid generation of peptides with randomly altered sequence variation that mimics antigen-antibody binding. With each generation, derivatized peptides are chosen with increasing affinity for the target of interest, until those with the greatest affinity are selected.

Scintillating Nanoparticles for Radiosensitization of Cancer Cells
Stephen Bradforth stephen.bradforth@usc.edu, Chemistry
Colin Hill ckhill@usc.edu, Radiation Oncology
Jay Nadeau jay.nadeau@mcgill.ca, Chemistry
Jonathon Ha kinha@usc.edu, Radiation Oncology
Eric Chang eric.chang@med.usc.edu, Radiation Oncology

Nearly 11 million people are diagnosed with cancer each year, and approximately half of these
will undergo radiation therapy with photons, fast electrons, X-rays, gamma rays, protons or
neutrons. Although there have been many advances in the accuracy of delivery of radiation to a tumor, this remains a challenge, as malignant tumors do not have well-defined borders and are often surrounded by radiosensitive structures or cells. This project will synthesize ultrasmall, water-soluble LaF3:Ce nanoparticles and conjugate to a cancertargeting molecule and a photosensitizer. In addition, the project will quantify reactive oxygen species (ROS) from each conjugate upon visible and Xirradiation, quantify the cytotoxicity of the conjugates to selected cancer cells in culture using an Xray therapeutic protocol, and determine the enhancement of the X-ray dose in the presence of the particles. Confirming these findings would lead to new clinical avenues for this treatment of refractory cancers.

Multiplexed Polysilicon Nanoribbon Sensors for Therapeutic Monitoring and Detection of Brain Cancer
Chongwu Zhou chongwuz@usc.edu Electrical Engineering
Mark Thompson met@usc.edu, Chemistry
Thomas Chen tcchen@usc.edu, Neurosurgery

The specific aims of this project are as follows: (1) We will develop the design and fabrication
of the polysi nanoribbon as a fully functional FET sensor. We will study the correlation between
the device’s electronic characteristics and several design parameters in order to optimize device
performance. (2) We will demonstrate nanoribbon detection of the cancer serum biomarker
Vascular Endothalial Growth Factor (VEGF), which has been demonstrated to be increased in
brain cancer. We will investigate the best antibody-to-surface binding chemistry to achieve the
clinically relevant sensitivity. Conventional antibodies will be used as capture probes in
phosphate buffered (PBS). (3) We will also investigate nanoribbon detection of 2 urinary
biomarkers MMP-2 and MMP-9, their effectiveness in brain cancer monitoring, and correlation
with brain cancer invasiveness. (4) And lastly, we will demonstrate the detection of the above 3
biomarkers in physiological solutions and calibrate our electrical signal with a those obtained
from conventional detection methods such as ELISA.

Telomerase Reprogramming Nanoparticles
(TeRN): Design and Validation of a Universal Cancer Therapeutic

Amir Goldkorn agoldkor@usc.edu, Internal Medicine
Nicos Petasis petasis@usc.edu, Chemistry

Cancer is a major health concern worldwide, accounting for millions of deaths and untold pain and suffering each year. There is an urgent need for new therapeutic strategies with greater efficacy, fewer toxicities, and – ideally – activity against many types of cancer. Although the development of such a universal cancer therapeutic is highly challenging due to the enormous phenotypic heterogeneity of cancer, one emerging possibility involves the enzyme telomerase. Whereas benign, terminally differentiated tissues have extremely low telomerase levels, over 90% of all human cancers have high levels of telomerase and rely on its activity for continuing proliferation. Indeed, telomerase is virtually unmatched as a therapeutic target that is both universal in malignant cells and unique to them, a profile which contributed to the recent awarding of the 2009 Nobel Prize to Blackburn, Greider and Szostak, the discoverers of this enzyme. However, despite early hopes, most efforts to inhibit telomerase have not been successful.

We have recently been pursuing a novel therapeutic strategy based on “telomerase reprogramming” which – rather than inhibiting the enzymatic function of telomerase – harnesses and reprograms its activity to induce rapid cell death in cancer cells. This approach has been highly effective across a broad spectrum of cancer types, but its development has been limited to in vitro models, because the plasmids used to reprogram telomerase are not suited for systemic delivery. Here, for the first time, we propose to surmount this challenge by rationally designing, synthesizing, and testing a Telomerase Reprogramming Nanoparticle (TeRN) capable of efficiently entering cancer cells and reprogramming their telomerase to induce cell death.

Innovation and Significance
• Telomerase reprogramming is a novel therapeutic strategy which exploits the telomerase activity present in >90% of all malignancies yet absent from normal tissues. Hence, it holds tremendous potential as a highly efficacious, non-toxic universal cancer treatment.

• Telomerase Reprogramming Nanoparticles (TeRN) offer a highly innovative implementation of this approach, transitioning telomerase reprogramming from its current in vitro stage to a potentially viable therapeutic agent capable of systemic delivery against cancer cells.

• The project is a highly collaborative, inter-departmental endeavor leveraging the strengths of a translational oncologist from the USC Keck School of Medicine (Goldkorn) and a synthetic/medicinal chemist from the USC Dornsife College (Petasis).

• The proposal constitutes a stepwise translational progression from nanoparticle design through chemical and biological validation, culminating in a novel therapeutic with major clinical impact that will be highly competitive for subsequent peer reviewed funding.

2011

Diagnostic Imaging of Smart Genetically Engineered Nanomedicines

John MacKay jamackay@usc.edu, Pharmacy
Zibo Li ziboli@usc.edu, Radiology
Peter Conti pconti@usc.edu, Radiology
Despite four decades of national engagement in the war-on-cancer, cancer caused 569 thousand deaths in the United States last year. Solid tumors are treated using surgery, radiation, chemotherapy, and more recently immunotherapy. Substantial effort has been expended to explore these modalities; however, more innovative ideas are needed to gain ground against cancer. To develop a new modality based on cancer nanomedicine, the MacKay laboratory combines the power of cellular protein expression, bioresponsive peptides, and self-assembly.

Our group studies polypeptides that are biologically inspired from a five amino acid motif identified in tropoelastin, a human extracellular matrix protein. These Elastin-Like Polypeptides (ELPs) are ideal for cancer nanomedicine because they can: (i) be tuned to self-assemble into multivalent polypeptide nanoparticles to modulate cellular uptake2; (ii) be seamlessly fused to proteins (enzymes, targeting ligands, therapeutics) without the need for bioconjugate chemistry; (iii) undergo slow proteolytic biodegradation3; and (iv) be non-immunogenic4. As a platform technology, ELPs provide a powerful approach to co-assemble multivalent core-shell nanoparticles decorated with functional peptides.

The immediate objective is to combine peptide-mediated nanoparticle assembly with Positron Emission Tomography (PET) to visualize the interaction of targeted nanoparticles within the tumor. Diagnostic imaging (optical, MRI, PET, CT, SPECT, ultrasound) is among the most powerful approaches available to improve the effectiveness of cancer therapies by: (i) enabling earlier detection; (ii) providing molecular information about the status of a cancer, which can guide therapy; (iii) following accumulation of drugs in cancer tissue; and (iv) enabling post-therapy monitoring of response. As the most sensitive imaging modality, PET is well-suited for tracking and quantification of nanoparticulate drug carriers in both research and clinical settings. To target cancer, the following strategy is proposed:

Innovation and Significance
• The development of a simple, biosynthetic approach to generate targeted polypeptide nanomedicines, which ultimately may be a platform for displaying a wide variety of protein/peptide ligands.

• Direct labeling of these peptides with novel PET imaging agents (sarcophagine-Cu-64) that permit non-invasive imaging over a period of several days.

• ELP-mediated assembly protects the PET label, encapsulates drugs, and presents targeting peptides.

Engineering Nanoparticles for Enhanced Cancer Therapeutics
Pin Wang pinwang@usc.edu, Chemical Engineering and Materials Science
Michael Wong mike.wong@med.usc.edu, Medicine

This project is developing tumor-targeted delivery of multifunctional nanoparticles packaged with therapeutic agents in order to maximize the antitumor effect and lower toxicity to the prostate cancer patient. The Wang lab from the Viterbi School of Engineering will team up with the Wong lab from the Keck School of Medicine to test a hypothesis that crosslinked multilamellar lipsomes (CMLs) displaying a tumor vasculature-specific peptide RRL can achieve targeted delivery of the anticancer reagent doxorubicin (Dox) to prostate tumors, and that such a form of nanomedicine can improve our ability to treat cancer. Three specific aims are devised to test this hypothesis.

• Synthesize and characterize the RRL-lipDox nanoparticle. In this aim, we plan to use a 4-step protocol to synthesize the nanoparticle RRL-lipDox, which is a Dox- encapsulating crosslinked multilamellar liposome with the surface-displayed tumor vasculature- specific peptide RRL. Parameters such as size, stability, encapsulation efficiency, in vitro release kinetics and cytotoxicity of the synthesized particle will be extensively characterized.

• Assess the selective binding of RRL-lipDox to tumor tissues in vitro. Prostate tumor-associated cell lines and human prostate cancer cryosections will be used to test the capability of RRL-lipDox to selectively bind to tumor tissues. Assays will also be conducted to determine the spatial relationship between nanoparticles and prostate tumor microenvironment.

• Examine the pharmacokinetics and in vivo potency of RRL-lipDox in preclinical mouse models. Pharmacokinetics, biodistribution, and toxicity of RRL-lipDox will be determined in mice. The human prostate xenograft model and the murine prostate transplantation model will be used to assess the ability of RRL-lipDox to target tumors and mount antitumor responses.

Innovation and Significance
The crosslinked multilamellar lipsome is a newly designed nanoparticle. RRL is an entirely new peptide capable of targeting tumor vasculature. From a scientific perspective, our proposed nanoparticle can become versatile platform technology for targeted delivery of various therapeutic reagents to different tumors. The success of this project has the potential to foster a paradigm shift in treating prostate and other malignant tumors. Successful implementation of our strategy will cure more individuals suffering from advanced cancer since it will now become possible to dose-escalate and dose- intensify cancer therapy resulting in a higher response rate against the targeted tumor with minimal toxicity to the patient. Targeted delivery will also allow for direct manipulation of the tumor and its microenvironment and open the possibility of synergistic combination therapies such as radiation, chemo-, immuno-, and cytotoxic therapy, thus vastly expanding the therapeutic repertoire.

An Ultrasound-Activated Nanoparticle Vehicle for Selective Imaging and Drug Delivery
Travis Williams travisw@usc.edu, Chemistry
Andy Chang achang@chla.usc.edu, Urology

This project will develop a dual imaging and drug delivery system. Our technology involves a nanoparticle in which a small molecule MRI contrast agent is anchored in the core and the periphery is coated with a selectively removable shell that masks the particle’s MRI contrast properties until it is removed. Additionally, our particle can encapsulate a small molecule drug and limit its ability to escape from its carrier until the desired time and place. The particle’s shell is designed to be removed by clinical ultrasound, which is applied externally. Thus, we are inventing a combined imaging and therapy system that is activated on command deep within the tissue, which will allow simultaneous activation of imaging contrast and delivery of a therapeutic agent.

We will construct phosphate-covered nanoparticles of variable size that contain an MRI contrast agent, load them (non-covalently) with lipophilic drugs, then apply a shell that will simultaneously keep the drug in and hold water out, so that the MRI contrast agent is masked. In principle, once IV injected into patients, this construct should aggregate in tumors because of size-exclusion effects of Enhanced Permeability and Retention (EPR). The particles can then be activated by ultrasound with simultaneous drug release and MRI contrast enhancement.

Innovation and Significance
This project will develop a “smart theragnostic” system that is simultaneously an externally activated imaging agent and an externally activated drug delivery system. As regards the former, several “smart” MRI contrast agents have been reported; these are agents that are responsive to their environment. Our strategy is fundamentally different because it is activated by external ultrasound, rather than environment. This has huge value because ultrasound is a rare form of radiation that can penetrate deep within tissue while causing minimal tissue damage.

Development of dual imaging and therapeutic systems is an emerging topic in medicine; “A main challenge in nanobiomedicine is the design of monodisperse and uniform nanomaterials with a size less than 100 nm that can efficiently encapsulate anti-cancer drugs at a high load and sustain-release their cargo at target sites.” Moreover, “Nanoplatforms that integrate imaging and therapeutic functions have received considerable attention as the next generation of medicine.”

The therapeutic component of this system is based on its ability to house, mask, and release selectively a drug cargo. There are numerous examples of polymeric or porous nanostructures that can non-covalently carry a drug cargo, and then release it slowly, like a “leaky bucket” or molecular sponge. Ours is different because the carrier is encased within a protective shell.