title: Effects over time of two platelet gel supernatants on growth factor, cytokine and hyaluronan concentrations in normal synovial membrane explants challenged with lipopolysaccharide.
abstract: BACKGROUND
  Platelet-rich plasma (PRP) preparations are a common treatment in osteoarthritis (OA) and inflammatory synovitis. However, there is ambiguity regarding the ideal concentration of leukocytes and platelets in these preparations necessary to induce an adequate anti-inflammatory and anabolic response in joint tissues, such as the synovial membrane. This research aimed to study, in normal synovial membrane explants (SME) challenged with lipopolysaccharide (LPS), the temporal effects (at 48 and 96h) of leukocyte- and platelet-rich gel (L-PRG) and pure platelet-rich gel (P-PRG) supernatants on the production and degradation of platelet associated growth factors (GF) (platelet derived GF isoform BB (PDGF-BB) and transforming growth factor beta-1 (TGF-β1)), pro-inflammatory (tumour necrosis factor alpha (TNF-α)) and anti-inflammatory cytokines (interleukin 4 (IL-4) and IL-1 receptor antagonists (IL-1ra)) and hyaluronan (HA).
  
  
  METHODS
  Synovial membrane explants (SMEs) from 6 horses were challenged with LPS and cultured for 96h with L-PRG and P-PRG supernatants at concentrations of 25 and 50 %, respectively. The SME culture medium was changed every 48h and used for determination by ELISA of PDGF-BB, TGF-β1, TNF-α, IL-4, IL-1ra and HA. These molecules were also determined in synovial fluid from the horses.
  
  
  RESULTS
  Both the 25 and 50 % PRG supernatants produced a molecular profile in the culture media unlike that of the SME challenged with LPS only. They presented GF, cytokine and HA concentrations very near to the concentrations of these molecules in normal synovial fluid when compared with the SME control groups (either with LPS or without LPS). However, in comparison with the rest of the SME treated groups, the 25 % L-PRG produced the most IL-1ra, and the 50 % P-PRG induced the sustained production of IL-4 and HA.
  
  
  CONCLUSIONS
  These in vitro findings suggest that anabolic and anti-inflammatory joint responses depend on the leukocyte and platelet concentration of the PRP preparation and on the volume of this substance injected. Moreover, it is possible, that leukoreduced PRP preparations are more effective for the medical treatment of patients with OA and inflammatory synovitis.
authors.affiliation: Grupo de Investigación Terapia Regenerativa, Departamento de Salud Animal, Universidad de Caldas, Calle 65 No 26-10, Manizales, Colombia. diana.rios@ucaldas.edu.co.
authors.forename: Diana L
authors.initials: DL
authors.lastname: Ríos
authors.affiliation: Grupo de Investigación Terapia Regenerativa, Departamento de Salud Animal, Universidad de Caldas, Calle 65 No 26-10, Manizales, Colombia. catalina.lopez@ucaldas.edu.co.
authors.forename: Catalina
authors.initials: C
authors.lastname: López
authors.affiliation: Grupo de Investigación Terapia Regenerativa, Departamento de Salud Animal, Universidad de Caldas, Calle 65 No 26-10, Manizales, Colombia. maria.alvarez_l@ucaldas.edu.co.
authors.forename: María E
authors.initials: ME
authors.lastname: Álvarez
authors.affiliation: The Terry Fox Laboratory, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, British Columbia, V5Z 1L3, Canada. isamudio@bccrc.ca.
authors.forename: Ismael J
authors.initials: IJ
authors.lastname: Samudio
authors.affiliation: Grupo de Investigación Terapia Regenerativa, Departamento de Salud Animal, Universidad de Caldas, Calle 65 No 26-10, Manizales, Colombia. carmona@ucaldas.edu.co.
authors.forename: Jorge U
authors.initials: JU
authors.lastname: Carmona
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000276:immunology / Q000378:metabolism*; D002458:Cell Fractionation; D003470:Culture Media / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism*; D005782:Gels; D006736:Horses; D006820:Hyaluronic Acid / Q000378:metabolism*; D018836:Inflammation Mediators / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D007962:Leukocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D053657:Platelet-Rich Plasma / Q000276:immunology / Q000378:metabolism*; D013582:Synovial Fluid / Q000276:immunology / Q000378:metabolism; D013583:Synovial Membrane / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D013997:Time Factors; D046509:Tissue Culture Techniques
chemical_list: D003470:Culture Media; D016207:Cytokines; D005782:Gels; D018836:Inflammation Mediators; D036341:Intercellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides; D006820:Hyaluronic Acid