Methods and systems for using therapeutic, diagnostic or prophylactic magnetic agents

Inventors

Shapiro, Benjamin • Emmert-Buck, Michael R.

Assignees

National Institutes of Health NIH • University of Maryland College Park • US Department of Health and Human Services

Abstract

Systems and methods are disclosed for directing magnetizable particles comprising therapeutic agents to a target volume, or for guiding magnetizable particles comprising therapeutic agents from a first target volume to a second target volume, at a distance using a magnetic field, to enable the treatment of diseased areas including areas deep inside a patient's body. The methods may be used to diagnose or treat diseased areas within a patient, for example tumors of the lungs, intestines, and liver, and is also useful in enhancing the permeability of solid tumors to chemotherapeutic agents.

Core Innovation

The invention discloses systems and methods for directing magnetizable particles comprising therapeutic agents to a target volume, or for guiding such particles from a first target volume to a second, using shaped magnetic fields externally applied to a patient. These methods enable the treatment of diseased areas including deep regions inside a patient's body, such as tumors of the lungs, intestines, and liver, and improve the permeability of solid tumors to chemotherapeutic agents. The methods include regional targeting for confining particles to an anatomical region and sweeping to move particles through regions to reach hard-to-access metastases.

The problem being solved is the inability of conventional magnetic drug delivery to target and retain therapeutic agents at deep tissue sites more than about 5 cm inside the body. Current magnetic targeting methods using static fields focus particles only near the body's surface because stable equilibrium points at depth are prohibited by Earnshaw's Theorem. Cancer treatments such as chemotherapy suffer from poor delivery and cellular uptake in metastatic tumors, especially those poorly vascularized or deep-seated. Existing approaches cannot confine drug delivery to volumes containing multiple metastases whose precise locations are unknown, limiting efficacy and causing systemic toxicity.

The invention overcomes these limitations by employing dynamic spatial and temporal shaping of magnetic fields created by multiple external magnets, including opposing sets, to direct and contain magnetizable therapeutic agents within defined deep target volumes or to actively sweep them from one volume to another. Feedback from sensing magnetizable particles inside the body enables optimized real-time control of magnetic field strengths and orientations. This approach allows treatment of the majority of clinically relevant metastatic tumors within an anatomical volume, reduces toxicity by sparing non-target tissues, and facilitates access to poorly vascularized lesions by sweeping magnetizable agents through adjoining volumes.

Claims Coverage

The patent includes two independent claims focusing on methods of treating patients by administering magnetizable objects and externally applying and altering static magnetic fields to direct or confine the objects within target volumes.

The independent claims focus on administering magnetizable objects to a patient and using externally applied, static magnetic fields whose arrangement is altered relative to the patient to drive or confine the magnetizable objects through desired target volumes, including sequentially from one volume to another. The inventive features center on dynamic alteration of static magnetic fields for regional and sweeping targeting within a patient.

Stated Advantages

Documented Applications