Protoporphyrin IX

About: Protoporphyrin IX is a research topic. Over the lifetime, 2250 publications have been published within this topic receiving 65544 citations. The topic is also known as: PpIX.

A Novel Nanosonosensitizer for Sonodynamic Therapy In Vivo Study on a Colon Tumor Model

Abstract: OBJECTIVES The particles in a liquid decrease the ultrasonic intensity threshold needed for cavitation onset. In this study, a new nanoconjugate composed of protoporphyrin IX and gold nanoparticles was used as a nucleation site for cavitation. The nonradiative relaxation time of protoporphyrin IX in the presence of gold nanoparticles is longer than the similar time without gold nanoparticles. METHODS This study was conducted on colon carcinoma tumors in BALB/c mice. The tumor-bearing mice were randomly divided into 6 groups (each containing 15 mice): (1) control, (2) protoporphyrin IX, (3) gold nanoparticle-protoporphyrin IX conjugate, (4) ultrasound alone, (5) ultrasound + protoporphyrin IX, and (6) ultrasound + gold nanoparticle-protoporphyrin IX conjugate. In the respective groups as indicated above, protoporphyrin IX or the gold nanoparticle-protoporphyrin IX conjugate was injected into the tumors. Ultrasound irradiation was performed on the tumors 24 hours after injection. Antitumor effects were estimated by evaluation of the relative tumor volume, doubling time, and 5-folding time for the tumors after treatment. The cumulative survival fraction of the mice and percentage of the lost tissue volume (treated) were also assessed in the different groups. RESULTS A significant difference in the average relative volumes of the tumors 13 days after treatment was found between the ultrasound + gold nanoparticle-protoporphyrin IX group and the other groups (P < .05). The longest doubling and 5-folding times were observed in the ultrasound + gold nanoparticle-protoporphyrin IX and ultrasound + protoporphyrin IX groups. CONCLUSIONS Protoporphyrin IX conjugated to gold nanoparticles has been introduced as a promising compound and a new sonosensitizer for improving the tumor response to sonodynamic therapy by reducing the relative tumor volume and increasing the cumulative survival fraction.

Method of detection and treatment of malignant and non-malignant lesions utilizing 5-aminolevulinic acid

Abstract: A method of detecting and treating malignant and non-malignant tissue abnormalities and lesions of the skin, conjunctives, respiratory, digestive and vaginal mucosa; endometrium and urothelium in which 5-aminolevulinic acid is administered to the patient in an amount sufficient to induce synthesis of protoporphyrin IX in the leisons, followed by exposure of the treated lesion to a photoactivating light in the range 350-640 nm

Techniques for fluorescence detection of protoporphyrin IX in skin cancers associated with photodynamic therapy.

Abstract: Photodynamic therapy (PDT) is a treatment modality that uses a specific photosensitizing agent, molecular oxygen, and light of a particular wavelength to kill cells targeted by the therapy. Topically administered aminolevulinic acid (ALA) is widely used to effectively treat cancerous and precancerous skin lesions, resulting in targeted tissue damage and little to no scarring. The targeting aspect of the treatment arises from the fact that ALA is preferentially converted into protoporphyrin IX (PpIX) in neoplastic cells. To monitor the amount of PpIX in tissues, techniques have been developed to measure PpIX-specific fluorescence, which provides information useful for monitoring the abundance and location of the photosensitizer before and during the illumination phase of PDT. This review summarizes the current state of these fluorescence detection techniques. Non-invasive devices are available for point measurements, or for wide-field optical imaging, to enable monitoring of PpIX in superficial tissues. To gain access to information at greater tissue depths, multi-modal techniques are being developed which combine fluorescent measurements with ultrasound or optical coherence tomography, or with microscopic techniques such as confocal or multiphoton approaches. The tools available at present, and newer devices under development, offer the promise of better enabling clinicians to inform and guide PDT treatment planning, thereby optimizing therapeutic outcomes for patients.

Fluorescence spectroscopy of normal mouse skin exposed to 5-aminolaevulinic acid and red light.

Abstract: Photobleaching and phototransformation of protoporphyrin IX (PpIX) was investigated in normal mouse skin. The PpIX was induced by topical application of 5-aminolaevulinic acid (ALA). Exposure to laser light (635 nm) caused photobleaching of PpIX fluorescence and formation of fluorescent products. Analysis of the fluorescence spectra revealed appearance of new fluorescent photoproducts during light exposure. The main photoproduct, supposedly chlorin-type photoprotoporphyrin (PPp), exhibited fluorescence with an emission maximum at 675 nm. The other products exhibited main fluorescence peaks at around 588 and 623 nm that can presumably be attributed to an endogenous metallo-porphyrin and water-soluble porphyrin(s), respectively. Our results indicate that light exposure causes alterations in the enzymatic pathway of PpIX synthesis from ALA and leads to accumulation of intermediate water-soluble porphyrins. ALA-induced porphyrins are transported away from the treated area and partly deposited in remote skin sites.