title: The effect of photosensitizer drugs and light stimulation on osteoblast growth.
abstract: OBJECTIVE
  A promising new treatment in dentistry involves the photodynamic process, which utilizes a combination of two therapeutic agents, namely a photosensitizer drug and a low dose of visible light. We investigated the in vitro effect of low intensity laser irradiation (visible light irradiation at 670 nm) using doses ranging between 0.5 and 3 J/cm(2), combined with nanoemulsion (NE) of the photosensitizer drug aluminum phthalocyanine chloride (AlClPc), ranging from 0.5 to 5 μmol/L, on the growth and differentiation of osteoblastic cells isolated from rat bone marrow.
  
  
  BACKGROUND
  Treatments using laser radiation of low intensity in dentistry are of great interest, especially in bucco-maxillofacial surgery and dental implantology, where this approach is currently employed to stimulate osteogenesis. In the presence of oxygen, the combination of these agents could induce cellular biostimulation, via an efficient noninvasive method.
  
  
  METHODS
  We have done the colorimetric MTT assay, collagen content, total protein content, ALP activity and bone-like nodule formation.
  
  
  RESULTS
  We observed that an increased number of viable cells was evident upon application of a laser dosage equal to 0.5 J/cm(2) when combined with 0.5 μmol/L of AlClPc/NE, suggesting cellular biostimulation.
  
  
  CONCLUSIONS
  It was possible to demonstrate that low intensity laser irradiation can play an important role in promoting biostimulation of osteoblast cell cultures. Therefore, whether biostimulation of osteoblastic cell cultures by photodynamic therapy or the cytotoxic effect of this therapy occurs only depends upon the light dose, and the results can be completely reversed.
authors.affiliation: Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Departamento de Química-Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Daniela Cervelle
authors.initials: DC
authors.lastname: Zancanela
authors.forename: Fernando Lucas
authors.initials: FL
authors.lastname: Primo
authors.forename: Adalberto Luiz
authors.initials: AL
authors.lastname: Rosa
authors.forename: Pietro
authors.initials: P
authors.lastname: Ciancaglini
authors.forename: Antonio Claudio
authors.initials: AC
authors.lastname: Tedesco
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000187:drug effects / Q000528:radiation effects; D049109:Cell Proliferation / Q000187:drug effects* / Q000528:radiation effects*; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism; D003124:Colorimetry; D004655:Emulsions; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology*; D028022:Low-Level Light Therapy / Q000379:methods*; D008954:Models, Biological; D009942:Organometallic Compounds / Q000494:pharmacology*; D010006:Osteoblasts / Q000187:drug effects* / Q000528:radiation effects*; D017319:Photosensitizing Agents / Q000494:pharmacology*; D011506:Proteins / Q000378:metabolism; D051381:Rats
chemical_list: D004655:Emulsions; D007211:Indoles; D009942:Organometallic Compounds; D017319:Photosensitizing Agents; D011506:Proteins; C044797:chloroaluminum phthalocyanine; D003094:Collagen