title: Induction of protoporphyrin IX in patient-derived synoviocytes, cartilage explants and chondrons after application of 5-aminolevulinic acid or its methyl ester.
abstract: OBJECTIVE
  To compare the accumulation of protoporphyrin IX between synoviocytes of patients with rheumatoid arthritis (RA) or osteoarthritis (OA) and cartilage explants (CE) as well as chondrons of patients with OA after the application of 5-aminolevulinic acid (ALA) or its methyl ester (ALA-Me).
  
  
  METHODS
  Samples of synovial and cartilage tissues were obtained from joint replacement surgeries. The accumulation of PpIX was determined by measuring fluorescence spectra from 2 × 10(5) synoviocytes or chondrons suspended in a glass tube or directly from CE surface after 2, 4, 8 and 24h of incubation with ALA or ALA-Me.
  
  
  RESULTS
  No differences were found between the average fluorescence intensity values of PpIX in synoviocytes of patients with RA and OA. These values were non-significantly higher after incubation with ALA in comparison with ALA-Me at almost all time points. The average fluorescence intensity of PpIX in CE and chondrons was about ten times lower than in synoviocytes. The presence of preparation of hyaluronic acid (HA) significantly enhanced PpIX induction in chondrons versus treatment only with ALA.
  
  
  CONCLUSIONS
  A potential for the selective synovial sensitization with endogenous PpIX in comparison with cartilage tissue has been demonstrated in vitro after application of ALA or ALA-Me.
authors.affiliation: Biophotonics Group of Laser Research Center, Faculty of Physics, Vilnius University, Sauletekio 9, bldg. 3, Vilnius LT-10222, Lithuania; State Research Institute Centre for Innovative Medicine, Zygimantu 9, Vilnius LT-01102, Lithuania. Electronic address: romualdas.rudys@ff.vu.lt.
authors.forename: Romualdas
authors.initials: R
authors.lastname: Rudys
authors.affiliation: State Research Institute Centre for Innovative Medicine, Zygimantu 9, Vilnius LT-01102, Lithuania. Electronic address: jdenkovskij@yahoo.com.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Denkovskij
authors.affiliation: State Research Institute Centre for Innovative Medicine, Zygimantu 9, Vilnius LT-01102, Lithuania. Electronic address: g.kirdaite@imcentras.lt.
authors.forename: Gailutė
authors.initials: G
authors.lastname: Kirdaitė
authors.affiliation: Biophotonics Group of Laser Research Center, Faculty of Physics, Vilnius University, Sauletekio 9, bldg. 3, Vilnius LT-10222, Lithuania. Electronic address: saulius.bagdonas@ff.vu.lt.
authors.forename: Saulius
authors.initials: S
authors.lastname: Bagdonas
mesh_terms: D000622:Aminolevulinic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology*; D001172:Arthritis, Rheumatoid / Q000473:pathology; D002356:Cartilage / Q000166:cytology; D019902:Chondrocytes / Q000737:chemistry / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D010003:Osteoarthritis / Q000473:pathology; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology*; D011524:Protoporphyrins / Q000032:analysis* / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013582:Synovial Fluid / Q000737:chemistry / Q000166:cytology* / Q000187:drug effects
chemical_list: D017319:Photosensitizing Agents; D011524:Protoporphyrins; C114767:delta-aminolevulinic acid methyl ester; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX