摘要:
The present invention relates to an artificial synovial fluid composition that mimics the tribological properties of human, osteoarthritic synovial fluid (SF) for the main purpose of in vitro wear testing. There is described an artificial synovial fluid composition comprising: a) a mammalian serum having i) a total protein concentration of from about 10 to about 45 g/L; ii) an albumin fraction of from about 55% to about 80% w/w %; iii) an α-1 globulin fraction of from about 3% to about 6% w/w %; iv) an α-2 globulin fraction of from about 5% to about 10% w/w %; v) a β-globulin fraction of from about 3% to about 20% w/w %; vi) a γ-globulin fraction of from about 5% to about 20% w/w %; vii) a calcium (Ca) concentration of from about 0.1 mmol/L to about 3 mmol/L; viii) a magnesium (Mg) concentration of from about 0.05 mmol/L to about 0.8 mmol/L; ix) an inorganic phosphate (P) concentration of from about 0.1 mmol/L to about 1.5 mmol/L; x) an iron (Fe) concentration of from about 0.001 mmol/L to about 0.1 mmol/L; xi) a peptide concentration at a 2,000 Da molecular weight cut-off of from about 0.005 g/L to about 10 g/L; xii) a maximal transition midpoint temperature, Tm-cp-max, of from about 330 K to about 350 K at a concentration molality of from about 0.005 to about 0.15 mmol/L measured at a scan rate of from about 20 K/hour to about 100 K/hour; xiii) a total enthalpy change, ΔH, of from about 650 kJ mol−1 to about 1200 kJ mol−1 at a set concentration molality of 0.05 mmol/l measured at a scan rate of 60 K/hour; xiv) a total entropy change, ΔS, of from about 1.5 kJ mol−1 K−1 to about 4 kJ mol−1 K−1 at a concentration molality of from about 0.005 mmol/l to about 0.15 mmol/l and a scan rate from about 20 K/hour to 100 K/hour; wherein the ratio of albumin to total globulin (α-1 globulin+α-2 globulin+β-globulin+γ-globulin fractions) in solution is from about 1.5 to about 3; b) a buffer for maintaining a solution osmolality of from about 200 mmol/kg to about 400 mmol/kg; c) hyaluronic acid (HA) at a concentration of from about 0.1 g/L to about 6 g/L; d) hyaluronic acid (HA) with a molecular weight of from 1 MDa to 4 MDa; and e) a pH level of about 7 to about 8.
摘要:
The present invention relates to an artificial synovial fluid composition that mimics the tribological and biochemical properties of human, osteoarthritic synovial fluid for in vitro testing of implantable materials. The artificial synovial fluid comprises new-born calf serum or alpha-calf serum (iron-free or iron-supplemented) that contains a specific total protein concentration, specific protein constituent fractions (albumin, α-1 globulin, α-2 globulin, β-globulin, and γ-globulin), specific trace element concentrations (Ca, Mg, inorganic P, and Fe), and a specific low-molecular weight peptide concentration important for in vitro testing of implantable materials. In addition, the artificial synovial fluid contains a hyaluronic acid concentration and level of osmolality (preferably using phosphate buffered-saline solution) to mimic the thermal stability (transition mid-point temperature, enthalpy, and entropy) and pH level as measured clinically.
摘要:
A ball (14) and cup (18) prosthesis is provided with articulating metal surfaces (25, 24), the surfaces (25, 24) having an area of intimate contact (.theta.) in which the surfaces (25, 24) are formed on radii (R.sub.3, R.sub.1) which differ by at most 50 micrometers. The area of intimate contact (.theta.) has a surface area that ranges from 0.12 .pi.R.sub.3.sup.2 to 1.65 .pi.R.sub.3.sup.2, and the centerline average surface roughness of the metal articulating surfaces (25, 24) in the area of intimate contact (.theta.) preferably is not greater than 0.1 micrometers.