title: Immunomodulation of tissue-engineered transplants: in vivo bone generation from methylprednisolone-stimulated chondrocytes.
abstract: Subcutaneously implanted, in vitro engineered tissue is generally affected by the immune system of the host even in autogenous transplantation. The aim of this study was to investigate immunomodulation of subcutaneously implanted tissue-engineered cartilage transplants by intramuscular methylprednisolone application. Transplants consisted of auricular rabbit chondrocytes, polylactide-polyglycolide co-polymer fleeces and species-specific fibrin or agarose. The transplants were subcutaneously implanted in the ridge. Thereafter, animals were separated into two groups, one with and one without methylprednisolone treatment. The specimens were histologically investigated after 6 and 12 weeks. Fleece fiber degradation was complete after 12 weeks, and all transplants showed areas of calcification. The corticosteroid-treated group presented pronounced trabecular bone generation without fibrous tissue infiltration. The untreated group showed sporadic islets of calcification without coherent bone formation, and adjacent fibrous tissue had infiltrated the transplants. Native controls and corticoid-treated transplants did not exhibit bone generation or signs of fibrous tissue infiltration. This study found that immunomodulation by intramuscular methylprednisolone application protects tissue-engineered autogenous chondrocyte transplants from fibrous tissue infiltration and induces trabecular bone formation.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center Benjamin Franklin, Free University of Berlin, Hindenburgdamm 30, 12200 Berlin, Germany. andreas.haisch@ukbf.fu-berlin.de
authors.forename: Andreas
authors.initials: A
authors.lastname: Haisch
authors.forename: Frank
authors.initials: F
authors.lastname: Wanjura
authors.forename: Cornelia
authors.initials: C
authors.lastname: Radke
authors.forename: Korinna
authors.initials: K
authors.lastname: Leder-Jöhrens
authors.forename: Andreas
authors.initials: A
authors.lastname: Gröger
authors.forename: Michaela
authors.initials: M
authors.lastname: Endres
authors.forename: Svea
authors.initials: S
authors.lastname: Klaering
authors.forename: Alexander
authors.initials: A
authors.lastname: Loch
authors.forename: Michael
authors.initials: M
authors.lastname: Sittinger
mesh_terms: D000818:Animals; D001707:Biopsy, Needle; D002356:Cartilage / Q000187:drug effects / Q000473:pathology* / Q000637:transplantation; D019902:Chondrocytes / Q000187:drug effects* / Q000637:transplantation; D004195:Disease Models, Animal; D005260:Female; D006084:Graft Rejection; D006085:Graft Survival; D008297:Male; D008775:Methylprednisolone / Q000494:pharmacology*; D010012:Osteogenesis / Q000187:drug effects* / Q000502:physiology; D011817:Rabbits; D012016:Reference Values; D012680:Sensitivity and Specificity; D023822:Tissue Engineering / Q000379:methods*; D016378:Tissue Transplantation / Q000379:methods; D014181:Transplantation Immunology; D014182:Transplantation, Autologous
chemical_list: D008775:Methylprednisolone