Zeta potential, size distribution and concentration of SCMBs4 via dealing with DI water, NaCl solution and PBS, respectively. And the size distribution of NMBs, CMBs, and SCMBs4. (a) Zeta potential of SCMBs4 after dealing with DI water, NaCl solution and PBS, respectively. (b) Size distribution and concentration of SCMBs4 after dealing with DI water, NaCl solution and PBS, respectively. (c) Size distribution and concentration of NMBs, CMBs and SCMBs4.