title: Low-power laser stimulation of tissue engineered cartilage tissue formed on a porous calcium polyphosphate scaffold.
abstract: OBJECTIVE
  Forming cartilage tissue in vitro that resembles native tissue is one of the challenges of cartilage tissue engineering. The aim of this study was to determine whether low-power laser stimulation would improve the formation of cartilage tissue in vitro.
  
  
  METHODS
  Bovine articular chondrocytes were seeded on the top surface of porous calcium polyphosphate substrates. After 2 days, laser stimulation was applied daily at a wavelength of 650 nm using a laser diode with energy densities of either 1.75 or 3 J/cm(2) for 4 weeks. Proteoglycan and collagen synthesis and matrix content were determined. Cartilage tissue morphology was evaluated histologically.
  
  
  RESULTS
  Histologically, there was no difference in the appearance or cellularity of the tissues that formed in the presence or absence of laser stimulation at either dosage. There were no differences in DNA content between treated and untreated constructs and live-dead assay confirmed that this treatment was not toxic to the cells. Laser stimulation at 3 J/cm(2) enhanced matrix synthesis resulting in significantly more tissue formation than laser stimulation at 1.75 J/cm(2) or untreated cultures.
  
  
  CONCLUSIONS
  Short exposures to low-power laser stimulation using a laser diode with 3 J/cm(2) dose improves cartilage tissue formation.
authors.affiliation: CIHR BioEngineering of Skeletal Tissues Team, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5.
authors.forename: Lu
authors.initials: L
authors.lastname: Gan
authors.forename: Carmen
authors.initials: C
authors.lastname: Tse
authors.forename: Robert M
authors.initials: RM
authors.lastname: Pilliar
authors.forename: Rita A
authors.initials: RA
authors.lastname: Kandel
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D002130:Calcium Phosphates; D002358:Cartilage, Articular / Q000166:cytology / Q000528:radiation effects*; D002417:Cattle; D002470:Cell Survival; D019902:Chondrocytes / Q000473:pathology; D005109:Extracellular Matrix / Q000502:physiology; D007834:Lasers; D023822:Tissue Engineering
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates