title: Tetracycline modulates collagen membrane degradation in vitro.
abstract: BACKGROUND
  Structural integrity of implanted bioabsorbable barrier membranes should be preserved for a sufficient time to ensure expected results. Collagen membranes are degraded by metalloproteinases (MMP). Their degradation rate can be altered either by enhancing structural integrity or by delaying the degradation process using MMP inhibitors. Tetracyclines (TTC) present inhibitory effects on matrix MMP. Immersing membranes in TTC solution before implantation can delay their degradation. The purpose of the present study was to evaluate the effect of collagen membranes immersed in varying TTC concentration solutions on the rate of their degradation in vitro.
  
  
  METHODS
  Collagen bioabsorbable membranes were prepared as 5 mm diameter membrane discs. Membranes were then incubated at 4 degrees C for 24 hours, in either phosphate buffered saline (PBS, Ca2+ and Mg2+ free) or with TTC-HCl dissolved in PBS concentrations of 5 mg/ml, 50 mg/ml or 100 mg/ml. After rinsing, membranes were incubated with either bacterial collagenase or cultures of human bone lineage cells. Membrane degradation was studied on days 2, 4, 7, and 14. Two- and 3-way analysis of variance was used to analyze results.
  
  
  RESULTS
  Samples supplemented with bacterial collagenase exhibited a statistically significant interaction between changes of free protein in the medium, antibiotic concentration used for the immersion, presence of collagenase in the medium, and incubation time (P<0.0001). Membranes incubated with bone cells exhibited similar degradation trends.
  
  
  CONCLUSIONS
  Collagen membranes immersed in 50 mg/ml TTC solution exhibited the longest degradation time, both in the clostridial collagenase and the human bone cell lineage assays. Immersion in a 50 mg/ml TTC solution before implantation will delay their degradation.
authors.affiliation: Department of Periodontology, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Israel.
authors.forename: O
authors.initials: O
authors.lastname: Moses
authors.forename: C E
authors.initials: CE
authors.lastname: Nemcovsky
authors.forename: H
authors.initials: H
authors.lastname: Tal
authors.forename: R
authors.initials: R
authors.lastname: Zohar
mesh_terms: D020341:Absorbable Implants; D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D001842:Bone and Bones / Q000166:cytology / Q000378:metabolism; D018929:Cell Culture Techniques; D003013:Clostridium / Q000201:enzymology; D003094:Collagen / Q000737:chemistry* / Q000378:metabolism; D017364:Collagenases / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000737:chemistry; D006801:Humans; D007101:Immersion; D061965:Matrix Metalloproteinase Inhibitors; D020782:Matrix Metalloproteinases / Q000737:chemistry; D008567:Membranes, Artificial; D011506:Proteins / Q000737:chemistry; D012965:Sodium Chloride; D013752:Tetracycline / Q000737:chemistry*; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D061965:Matrix Metalloproteinase Inhibitors; D008567:Membranes, Artificial; D011506:Proteins; D012965:Sodium Chloride; D003094:Collagen; D017364:Collagenases; D020782:Matrix Metalloproteinases; D013752:Tetracycline