We investigate the statistics of polymer capture by a nanopore using Brownian dynamics simulations. It is found that when the velocity flux is greater than a critical velocity flux, the capture picture is a random selection process, otherwise it tends to a statistical process governed by energetic considerations. In addition, the chain ends capture probability decreases as the chain length increases and satisfies a power-law scaling of P0（N）-N^-0.8.
New pH-responsive saccharide hydrogels were designed and prepared using curdlan derivatives（curdlan-Bochistidine, CUR-HIS）. The CUR-HIS hydrogels possessed highly porous structures. The swelling ratios of CUR-HIS hydrogels increased with the degree of substitution of Boc-histidine groups. And the addition of 0.5 mol/L Na Cl provoked a sharp reduction of swelling ratio of CUR-HIS hydrogels. Bovine serum albumin（BSA） can be efficiently encapsulated into CUR-HIS hydrogels. Moreover, the release profiles of BSA at different p H values from CUR-HIS hydrogels were significantly different. These hydrogels showed good biocompatibility in the cytotoxicity assays. The CUR-HIS hydrogels are of great potential in biomedical applications such as protein delivery systems.
