Effect Of Degraded Algal Polysaccharide On Growth, Aggregation And Crystal Face Of Calcium Oxalate

Laminaria Japonica sulfated polysaccharides(LPS) were extracted and degraded by CTAB with hydrogen peroxide(H₂O₂) from average molecular weight of 170 000 to 9549 or so.The mass fraction of sulfate group(OSO₃^2-) decreased from 5.09%to 4.94%.With this method,the degradation velocity was more faster and the amount of reagent was more less.Further more,the technology of this method was simple.The content of sulfated group basically remained constant and the solubility of LPS greatly improved.Consequently,the biological activity was significantly enhanced.The effect of degraded LPS on the urinary stone calcium oxalate crystals in aqueous solution and diluted urine was investigated by Scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR),X-ray Diffraction(XRD),Atomic absorption spectrometry(AAS),Zetasizer Nano-ZS.The experimental results proved that the degraded LPS could inhibit the growth of thermodynamic stable calcium oxalate monohydrate,and induce the formation of thermodynamic metastable calcium oxalate dihydrate.As the concentration of degraded LPS increased from 0.3 to 6 mg/L,the mass percentage of COD crystals increased from 0 to 52.2%.In diluted urine of healthy people,the adsorption of polysaccharide chains on the((?)01),(010),(120) and(100) face of COM crystals was different,due to the complexity of degraded LPS structures.As the concentration of degraded LPS increased from 0.2 to 5 mg/L, the size of COM crystals decreased from 14.4μm×8.8μm to 9.8μm×4.2μm,the aspect ratio increased from 1.64 to 2.45,the ratio of the intensity of diffraction peak((?)01) plane to(010) plane of COM crystals(I_((?)01)/I₍₀₂₀₎) decreased from 57.8 to 27.2,while the size of COD crystals increased from 7.0μm×5.6μm to 9.5μm×8.1μm.The shape of COM crystals turned to lamellar rectangle.In diluted urine of urinary calculi patients,the COM crystals possess hexagonal morphology with sharp edges and angles.In addition,more aggregates were obtained. When the concentration of degraded LPS was higher,the COD crystals with larger(100) face were obtained.The effect of ionic strength and pH on calcium oxalate crystals was significant with the presence and absence of SSPS in aqueous solution.In blank aqueous solution with the absence of SSPS,more aggregates and penetratin twins of COM crystals were obtained with the absence of NaCl.As IS increased to 0.5 M,the COD crystals were obtained due to the chemical microenvironment surrounding Ca²⁺ and C₂O₄^2- have a change.The inhibition of SSPS on calcium oxalate crystals was weakened by the increasing of ionic strength.With the presence of SSPS,the inhibitory effect was the best when pH=7 because of the lowest intensity of(020) diffraction peak and non-aggregates.The inhibition effect of two polysaccharides on calcium oxalate crystals was investigated in our experiments.We expected to provide new insight in drugs exploitation of urinary stone therapy and prevention of urolithiasis.