In vitro function study of different negative charge Pullulan nanoparticles for sentinel lymph node angiography.

Backgroud Many dyes or radioactive markers used for sentinel lymph node (SLN) have the shortcomings of false positive and radiation injury. Indocyanine green (ICG) seems to have a lower false positive rate and tissue damage, without a clear field of vision during the operation. Methods For the shortcomings, we successfully synthesized three anionic pullulan materials, changed the degree of hydrophobic for size controlling (< 50nm) to prepare CHP nanoparticles (NPs) and changed the succinyl degree to prepare CHPC NPs with different negative surface potential. Results The size of those NPs were less than 50nm under (transmission electron microscope) TEM, with hydrodynamic size of 90.67±2.2nm of CHP, 105.8±1.7nm of CHPC1 and 115.9±2.3nm of CHPC2. Moreover, the Zeta potential of CHP, CHPC1 and CHPC2 were -1.9±0.2mV, -9.6±0.3mV and -19.4±0.7mV. The size of ICG-loading CHP, CHPC1 and CHPC2 NPs increased to 109.4±2.7nm, 113.8±1.2nm and 30.6±3.5 nm, as the zeta potential decreased to -2.7±0.4mV, -12.5±1.6mV and -23.1 ±1.2mV. With the increasing degree of succinyl, the size increased and the zeta potential decreased. At the same time, the higher degree of succinyl drug-loading NPs have lower release and have increased the stability of ICG. We found that the blank-NPs had no significant toxicity to normal cells (HSF), as the ICG@CHP group had larger toxicity than the CHPCs and control. Moreover, the cellular uptake was decreased with the increased degree of succinyl. Conclusion In this study, we successfully prepared CHPC2 carriers with the maximum negative surface charge, for follow-up research and providing new ideas for SLN.