The occurrence of restenosis following percutaneous transluminal coronary angioplasty is prevented or inhibited using a photopheresis treatment method, In accordance with the photopheresis treatment method, a photoactive compound such as 8-methoxypsoralen is administered to the patient's blood or affected tissue, or some fraction thereof, in vitro or in vivo using conventional administration routes. A portion of the patient's blood or affected tissue is then treated (preferably, extracorporeally) using photopheresis, which comprises subjecting the blood or affected tissue to electromagnetic radiation in a wavelength suitable for activating the photoactive compound, such as ultraviolet light, preferably long wavelength ultraviolet light in the wavelength range of 320 to 400 nm, commonly called UVA light. The treated blood or affected tissue, or a fraction thereof, is returned to the patient (in the case of extracorporeal photopheresis) or remains in the patient (following in vivo photopheresis).

A broad class of photosensitive compounds having enhanced in vivo target tissue selectivity and versatility in photodynamic therapy. Many furocoumarin compounds, such as psoralens, exhibit cytostatic activity when photoactivated but exhibit little in vivo specificity for selectively accumulating in any particular target tissue such as atheromatous plaques. Reactive Oxygen Producing Photosensitizers ("ROPPs") are photoactivatable compounds having an affinity for hyperproliferating cells (such as atheromatous plaque cells), which when photoactivated, produce cytotoxic reaction products. The photoactivity of a ROPP, such as a porphyrin, may be reduced by metalating the porphyrin while the selective affinity of the metalized ROPP for hyperproliferating tissue remains substantially unchanged. By linking a furocoumarin compound to a ROPP to form a F-ROPP, the cytostatic properties of the furocoumarin portion of the F-ROPP can be exploited while the selective affinity of the ROPP portion of the compound for hyperproliferating cells such as atheromatous plaque provides enhanced tissue selectivity without cytotoxicity. In vivo, certain F-ROPPs may be forced to selectively accumulate in a target tissue by illuminating only the target tissue with light having a wavelength operable for photoactivating the F portion of the F-ROPP thereby causing the F-ROPP to either form a monoadduct with or crosslink the cellular DNA in the target tissue. Light of a second wavelength can then be delivered to the target tissue to photoactivate the ROPP portion causing further interference with cellular activity.

A cryotherapy method for reducing tissue injury after balloon angioplasty or stent implantation contemplates use of a well insulated, low profile catheter designed to transport a low temperature medium such as gas, fluid or a mixture thereof at a particular temperature over a guide wire to the site of a lesion. The lesion may or may not have undergone previous procedure for balloon angioplasty or stent implantation. The cryo-medium is introduced from a well insulated storage chamber having a small nozzle to which a conduit may be attached to allow conveyance of the fluid to a point of use. A handheld valve is incorporated into the conduit to allow the surgeon to closely control the flow of the cryo-medium to the point of use. The conduit extends downstream of the valve and is fluidly connected to the catheter that is positioned at the point of the lesion in the body. If desired, antibiotics, anticoagulants, antiproliferative agents, gene materials, etc. may also be dispersed along with the cryo-medium intraluminally. Such additional substances may be mixed with the cryo-medium in the storage chamber before introduction into the catheter or concurrently with introduction into the catheter. Several alternative catheter structures are contemplated in accordance with the teachings of the present invention.

TGF-beta activators and TGF-beta production stimulators are employed to maintain or increase vessel lumen diameter in a diseased or injured vessel of a mammal. Conditions such as restenosis following angioplasty, vascular bypass grafts, transplanted organs, atherosclerosis or hypertension are characterized by a reduced vessel lumen diameter. In a preferred embodiment of the invention, TGF-beta activators and production stimulators inhibit abnormal proliferation of smooth muscle cells. TGF-beta activators or production stimulators that are not characterized by an undesirable systemic toxicity profile at a prophylactic dose are also amenable to chronic use for prophylactic purposes with respect to disease states involving proliferation and/or migration of vascular smooth muscle cells over time. Further provided is a method for determining TGF-beta in vitro, thereby identifying a patient at risk for atherosclerosis and monitoring a recipient that has received one or more administrations of a TGF-beta activator or production stimulator.

Methods are provided for inhibiting stenosis following vascular trauma or disease in a mammalian host, comprising administering to the host a therapeutically effective dosage of a therapeutic conjugate containing a vascular smooth muscle binding protein that associates in a specific manner with a cell surface of the vascular smooth muscle cell, coupled to a therapeutic agent dosage form that inhibits a cellular activity of the muscle cell. Methods are also provided for the direct and/or targeted delivery of therapeutic agents to vascular smooth muscle cells that cause a dilation and fixation of the vascular lumen by inhibiting smooth muscle cell contraction, thereby constituting a biological stent. Also discussed are mechanisms for in vivo vascular smooth muscle cell proliferation modulation, agents that impact those mechanisms and protocols for the use of those agents.