In Vitro Biosafety Evaluation of Biodegradable Fluorinated Polyurethane Micelles

Objective To systematically evaluate the in vitro cytotoxicity and hemocompatibility of fluorinated polyurethane (FPU) micelles using international standardized methods, thereby providing a safety basis for their clinical application.

Methods Biodegradable FPU was synthesized using a two-step polymerization method. The hydrated particle size and the zeta potential of the micelles were measured by dynamic light scattering, and their morphology was observed by transmission electron microscopy. In accordance with the relevant standards for in vitro cytotoxicity testing specified in the biological evaluation guidelines for medical devices (ISO 10993-5:2009, GB/T 16886.5-2017, and GB/T 16886.4-2022) NIH/3T3 and SKOV3 cells were used to assess the effects of FPU micelles at various concentrations on cell proliferation, membrane permeability, and apoptosis after 24, 48, and 72 hours of treatment. Flow cytometry was used to analyze the effects of FPU micelles on the cell cycle of NIH/3T3 and SKOV3 cells. Additionally, an in vitro hemolysis assay was performed to evaluate the hemocompatibility of FPU micelles.

Results The particle size of FPU micelles was approximately 132.5 nm, with a polydispersity index (PDI) of 0.096, which is below 0.150, indicating uniform particle size. The zeta potential of FPU micelles was －21.5 mV. After treatment with FPU micelles at various concentrations, the proliferation activity of NIH/3T3 and SKOV3 cells was not affected, and no significant toxicity was observed. Furthermore, cell membrane permeability was not significantly altered, and no significant apoptosis was induced. Cell cycle analysis showed that after 72 hours of treatment, the proportion of cells in the G1 phase increased, while the proportions of cells in the S and G2 phases decreased, suggesting potential G1 phase arrest. However, no significant toxicity was observed. Furthermore, hemocompatibility experiments demonstrated that FPU micelles did not cause erythrocyte rupture or hemolysis, further confirming their favorable biocompatibility.

Conclusion FPU micelles did not exhibit significant cytotoxicity or hemolysis in vitro, and cell cycle analysis indicated no notable toxicity, demonstrating good biosafety.