Evaluation and characterization of starch nanoparticles for adsorption of urea from dialysates

Starch nanoparticles (SNPs) was produced from type-A, B and C native starches (corn, potato and Trichosanthes kirilowii pulp starches respectively), via the nanoprecipitation method. The SNPs showed different amylose contents, water contact angles, surface morphologies and urea clearance performances. In this work, to examine the parameters of SNPs that may change the urea adsorption capacity, urea adsorption performance in adsorption environments with different pH values, urea concentrations, and adsorption times was examined. Thereafter, the characteristics of SNPs were tested by water contact angle measurements (WCA), transmission electron microscopy, specific surface area measurements, gel permeation chromatography, and zeta potential analysis. The results showed that the Trichosanthes kirilowii pulp (C) SNPs show better adsorption than the corn (A) and potato (B) SNPs. The hydrophobicity of SNPs promotes the urea adsorption of the SNPs. Using grey relational analysis, it was found that WCA and Mn are the critical parameter affecting the adsorption performance, with WCA and Mn within the ranges of 31–33° and 1900–2100 kDa, respectively, were found to be the conditions for optimal urea adsorption.