Light-activated drug delivery method and device

A method of delivering an agent of biological effect to a specific therapeutic site within an animal comprising:

• containing the agent of biological effect within a body made from a (i) substance suitable to contain the agent of biological effect but susceptible to a chemical to lose containment integrity, and (ii) a photosensitive precursor of the chemical, the substance of the body being stable to contain the agent within the animal both en route to and at the therapeutic site but always susceptible to the chemical to lose containment integrity;
• and
• illuminating the therapeutic site with radiation sufficient so as to produce from the chemical precursor the very chemical that causes lost of containment integrity of the substance of the body, therein loosing the agent of biological effect from the body into the animal at the therapeutic site.

A method of delivering a chemical agent to a specifically selected therapeutic site within an animal comprising:

• holding the chemical agent in association with a matrix that is made from a polymer and a photosensitive precursor of an acid, the matrix being stable to contain the chemical agent both en route to and at the therapeutic site within the animal, but the matrix losing integrity to contain the chemical agent should the polymer from which the matrix is made become exposed to an acid derived from the precursor;
• and
• selectively illuminating the selected therapeutic site with two beams of radiation so as to produce (i) by process of two-photon absorption acid, (ii) from the acid precursor that is within matrix present at the therapeutic site, the acid, this produced acid causing the polymer from which the matrix is made to lose integrity to contain the chemical agent and, consequently to this lost of containment integrity, loosing the chemical agent into the animal at the selected therapeutic site.

A method of delivering a agent of biological effect to a specific therapeutic site in an animal comprising:

• physically containing an agent of biological effect, which agent is substantially impervious to x-ray radiation, within a body that is (i) stable to contain the agent in an animal both en route to and at a therapeutic site, while remaining (ii) sensitive to x-ray radiation to substantially lose containment capability;
• and
• illuminating the therapeutic site with x-ray radiation so as to substantially destroy the containment capability of the body, loosing the agent of biological effect.

A vehicle for delivery of a drug to a therapeutic site within an animal, the vehicle comprising:

• a drug-encapsulating sheath stable to contain a drug in an animal both en route to and at the therapeutic site but dissolvable by a chemical, the sheath consisting essentially of a binder material (i) stable to contain the drug in the animal both en route to and at the therapeutic site but (ii) dissolvable by a chemical, and
• a photochemical, also stable in the animal both en route to and at the therapeutic site, responsive to radiation for producing the chemical which will dissolve the binder material, loosing the contained drug.