Transcript Oral Presentation 4 - Research

Field-Induced
Magnetic Nanoparticle
Drug Delivery
April 9, 2003
BME 273 Group 15
Team Leader : Ashwath Jayagopal (BME, EE, MATH)
Members : Sanjay Athavale (BME) and Amit Parikh (BME)
Advisor : Dr. Dennis Hallahan, Chairman of Radiation Oncology and Professor of
Biomedical Engineering and Radiation Oncology, Vanderbilt University
Course Instructor : Dr. Paul King, PE, Associate Professor of Biomedical
Engineering, Mechanical Engineering and Anesthesiology, Vanderbilt University
Rationale for New Cancer Treatments
• Since 1990 16 million diagnosed with cancer, 5-year survival rate is 62%, estimated
1,400,000 new cases this year (American Cancer Society)
• Current treatments such as chemotherapy, surgery, and radiation therapy have
disadvantages of extremely harmful side effects, high cost, and long duration
• Side effects include lower blood counts, flu-like symptoms, hair loss, swelling, scars
and wounds, weight fluctuation, nausea, diarrhea, healthy cell death, general
weakness of all systems
• All treatment methods have a range of costs from $1000-$100,000+ depending on
the specific case and treatment (ACS)
• Multiple visits may be required for surgical procedures, chemotherapy, and radiation
treatment. There is often a long wait associated with getting treatment
A Cancerous Tumor Matrix
•Matrix -- fibrous internal structure of a tumor,
characterized by low permeability; contains cells in
various stages of development, proliferation of blood
vessels, connective tissue (collagen, laminin)
•The matrix contains an interstitial basement membrane
that forms the framework to which cells are attached
•The basement membrane separates cells from
mesenchymal connective tissue and provides spatial
orientation and stability
•Important for the growth and differentiation of cells
and angiogenesis within a tumor
•Tumors depend on blood vessels for nutrients and
oxygen, therefore inhibition of angiogenesis is a goal
VUMC Radiation Oncology, using laser scanning
microscopy of a squamous cell carcinoma tumor.
Highlighted strands indicate blood vessels,
connective tissue fibers, and small tumor cells.
Project Objectives
•Develop and test an effective process for facilitating site-specific drug
delivery to a tumor using the properties of paramagnetic iron oxide
nanoparticles
•Use an externally applied magnetic field to precisely guide nanoparticle
movement through a tumor matrix
•Enhance nanoparticle delivery using local irradiation and biological
factors (an enzyme library which enhances tumor permeability to
nanoparticles)
•Reduce problems associated with current treatment methods dramatically,
especially harm to healthy tissue
Background
• Using recently developed methods,
medications can be encased in
magnetic nanoparticles
• Given antibody coating, avoids
immune reaction, yet lasts in
circulation
• Superparamagnetic iron oxide
nanoparticles exhibit strong magnetic
properties given an externally applied
field, can be produced in uniform sizes
and properties (Georgia Tech
consortium, Dr. John Zhang, lead
investigator)
• Guided missiles that can deliver tumor
-killing drug to affected area without
harming healthy tissue
Shown here is a ring trap designed to control magnetic
nanoparticles (iron oxide) by applying a current. Figure a.)
shows the result in a nanoparticle-filled medium when no
current is applied. In b.), a 0.35 A current is applied, and
the nanoparticles accumulate at the center of the ring. This
is analogous to what would be desirable in using a
nanoparticle-based tumor drug delivery mechanismLee et.
Al, Harvard Univ., J. Appl Phys 79/20, Nov. 2001.
Background
• Matrigel (BD Clontech) is a reconstituted basement membrane -- derived from
Engelbroth-Holm-Swarm (EHS) mouse sarcoma, contains laminin, proteoglycan,
collagen IV, enactin, and other basement membrane proteins responsible for
transport in/out tumor
• Excellent tumor model, a rich source of ECM proteins, facilitates angiogenesis,
nurtures tumor endothelial cells, can induce endothelial cell differentiation in the
same pattern as a live tumor
• Is a cost-effective, safer alternative to in vivo, allows for observation of
nanoparticles without imaging methods
• In order to enhance nanoparticle delivery, enzymes can be used (e.g. collagenase,
amylase) to digest these basement membrane proteins to increase permeability
• Tumor irradiation enhances permeability of the membrane
Light micrograph showing angiogenesis in Matrigel solution. Endothelial cells have
aligned in a 3-D spatial orientation to create blood vessels in a pattern similar to a
tumor matrix. (BD Clontech 2003)
Methods
• Primary design is chemical in nature and involves
degradation of the tumor matrix
• Nanoparticle-enzyme interaction is based on the
“sticky” nature of the carbon coating
• Enzymes should specifically target the
constituents of the tumor matrix
• Irradiation of the tumor weakens critical bonds
found in the connective tissue of the tumor matrix
Methods
Experimental Setup
• Washing of nanoparticles with PBS solution to eliminate
impurities
• Coating of nanoparticles with specific enzymes including trypsin,
collagenase, and amylase
• Irradiation of tumor
• Injection of nanoparticles into tumor matrix
• Application of magnetic field
Results
• Nanoparticles successfully moved through
minimally resistant fluid environment.
• Uncoated Nanoparticles failed to move through
Matrigel matrix after 4 hours.
• Nanoparticle-enzyme combination showed
significant movement through the Matrigel
matrix.
Interpretation of Results
• Coated nanoparticles show promise in allowing controlled, widespread
movement throughout tumor matrix.
• In a clinical setting these Nanoparticle-enzyme combinations could
potentially take the place of previously used nanoparticles.
• Design is simple, easy to construct, and requires no expensive
electromagnets.
• Our design solves problems associated with clumping, homogenous
distribution, and biocompatibility.
Future Considerations
• New Nanoparticle coatings
-- Amylase/Collagenase
• Tumor irradiation by way of X-rays
• Higher Concentrations of degradation enzymes
• Incorporation of endothelial cells into Matrigel matrix
• Try to use different drugs as nanoparticle enclosures
• Use of cell-receptor mechanisms in conjunction with enzymes
to enhance acceptance of nanoparticles into tumor matrix
Market Potential
• With further development of this technology and understanding of drugnanoparticle relationships, could be applied to numerous tumor varieties,
benefiting all cancer patients
• Drug delivery industry estimated worth $24 billion
• Implementation in any hospital
• Cost effective process is appealing at around $1000-2000 depending on drug
used; would lower cost of cancer treatment in addition to reducing risks and
side effects, if proven effective
Conclusions
• We have covered much ground in developing a process that could
potentially be used to treat tumors
• Our process has been demonstrated to enhance drug-containing
nanoparticle mobility through a tumor matrix (i.e. mobility with our
enzyme mix, no movement without it); has been called “promising” by
several researchers
• Market potential is strong
• Experimental procedures used are reproducible
• Amount of research that could be done within this area has no bounds
Acknowledgements
• Dr. Dennis Hallahan, VUMC Radiation Oncology, VU BME
• Dr. Ling Geng, VUMC Radiation Oncology
• Dr. Paul King, PE VU BME
• Chris Iversen, VUMC Radiation Oncology
• Sam Kuhn, VU BME
• Dr. John Zhang, Georgia Tech Biochemistry
• Dr. Jayaramn Rao, LSUMC (New Orleans)