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Effects of sodium chloride, guanidine hydrochloride and sucrose on the rheological properties of hyaluronic acid solutions
Vol. 33, No. 1
18th Meeting of theJapanese Society of Biorheology
79
Effects of sodium chloride, guanidine hydrochloride and sucrose on the rheological properties of hyaluronic acid solutions Y.MO, T.TAKAYA, AND K.NISHINARI FACULTY OF HUMAN LIFE SCIENCE, OSAKA CITY UNIVERSITY, SUGIMOTO, SUMIYOSHI-KU, OSAKA, 558 JAPAN
INTRODUCTION HA is a major macromoleeularcomponent of the intercellular matrix of most connective tissues. For its prominent viscoelasticproperties, HA acts as a lubricant and shock absorber in synovial fluid. MATERIALS AND METHODS HAs, extracted from the culture medium of Streptococcus equi and purified. Viscoelastic measurements were performed on a RFSII (RheometricsFluids Spectrometer). RESULTS AND DISCUSSION The effects of sodium chloride (NaCl), guanidine hydrochloridc (GuHCI), and sucrose on the theological properties of hyaluronic acid (HA) solutions were studied. NaC1and GuHC1 decreased both storage and loss moduli, whilst sucrose increased both moduli. The cross over frequency shifted to higher frequencies by the addition of NaCl and GuHC1, whilst it shifted to lower frequencies by the addition of sucrose. The coil overlap concentration C* was determined for HA solutions with and without NaC1, GuHC1and sucrose by the plot of zero shear viscosity vs. HA concentration. C* shifted to higher concentrations by adding NaCl or GuHC1 whilst sucrose shifted C* to lower concentrations. The effect of sucrose was attributed to the enhancement of entanglement formation probably by newly created hydrogen bonds and the effect of NaC1 or GuHCI was attributed to the electrostatic shielding of repulsion between carboxyl groups in HA.
DOUBLE W A L L LAYER MODEL OF BIOFLUIDS FLOWING IN A CAPILLARY Teruko Nakamura, Kenichi Sakon*, Akemi Yamamoto and Takeshi Mineshita Dept. of Food Science, Tezukayama College, Nara *Dept. of Research and Development, Noevir Co. Ltd., Shiga Relationship between flow properties and dispersion states of biofluids such as milk and blood in a narrow capillary tube have been studied by viscometric measurement and photomicroscopic observation. Both of these biofluids show the characteristic flow property of n o n - Newtonian fluidity and, these viscosity values decrease with the decreasing of capillary b o r e - size of the viscometer. These shear dependence on the viscosity and capillary b o r e - size dependence on viscosity values might be attributed to the formation of aggregate structure of biofluids in a capillary. In a narrow capillary, each of these biofluids will form some different aggregate structures, and these aggregate structure formation will change with the sort of the origin of biofluid and in b o r e - size of the capillary tube. From these experimental results, flow model of biofluids was derived and assumed the wall layer composed of double layers in a flowing liquid in a capillary tube.
18th Meeting of theJapanese Society of Biorheology
79
Effects of sodium chloride, guanidine hydrochloride and sucrose on the rheological properties of hyaluronic acid solutions Y.MO, T.TAKAYA, AND K.NISHINARI FACULTY OF HUMAN LIFE SCIENCE, OSAKA CITY UNIVERSITY, SUGIMOTO, SUMIYOSHI-KU, OSAKA, 558 JAPAN
INTRODUCTION HA is a major macromoleeularcomponent of the intercellular matrix of most connective tissues. For its prominent viscoelasticproperties, HA acts as a lubricant and shock absorber in synovial fluid. MATERIALS AND METHODS HAs, extracted from the culture medium of Streptococcus equi and purified. Viscoelastic measurements were performed on a RFSII (RheometricsFluids Spectrometer). RESULTS AND DISCUSSION The effects of sodium chloride (NaCl), guanidine hydrochloridc (GuHCI), and sucrose on the theological properties of hyaluronic acid (HA) solutions were studied. NaC1and GuHC1 decreased both storage and loss moduli, whilst sucrose increased both moduli. The cross over frequency shifted to higher frequencies by the addition of NaCl and GuHC1, whilst it shifted to lower frequencies by the addition of sucrose. The coil overlap concentration C* was determined for HA solutions with and without NaC1, GuHC1and sucrose by the plot of zero shear viscosity vs. HA concentration. C* shifted to higher concentrations by adding NaCl or GuHC1 whilst sucrose shifted C* to lower concentrations. The effect of sucrose was attributed to the enhancement of entanglement formation probably by newly created hydrogen bonds and the effect of NaC1 or GuHCI was attributed to the electrostatic shielding of repulsion between carboxyl groups in HA.
DOUBLE W A L L LAYER MODEL OF BIOFLUIDS FLOWING IN A CAPILLARY Teruko Nakamura, Kenichi Sakon*, Akemi Yamamoto and Takeshi Mineshita Dept. of Food Science, Tezukayama College, Nara *Dept. of Research and Development, Noevir Co. Ltd., Shiga Relationship between flow properties and dispersion states of biofluids such as milk and blood in a narrow capillary tube have been studied by viscometric measurement and photomicroscopic observation. Both of these biofluids show the characteristic flow property of n o n - Newtonian fluidity and, these viscosity values decrease with the decreasing of capillary b o r e - size of the viscometer. These shear dependence on the viscosity and capillary b o r e - size dependence on viscosity values might be attributed to the formation of aggregate structure of biofluids in a capillary. In a narrow capillary, each of these biofluids will form some different aggregate structures, and these aggregate structure formation will change with the sort of the origin of biofluid and in b o r e - size of the capillary tube. From these experimental results, flow model of biofluids was derived and assumed the wall layer composed of double layers in a flowing liquid in a capillary tube.