Paclitaxel Has a Reduced Toxicity Profile in Healthy Rats After Polymeric Micellar Nanoparticle Delivery

BACKGROUND: Nanocarrier platforms have been indicated to have great potential in clinical practice to treat non-small cell lung cancer (NSCLC). Our previous Phase III clinical study revealed that polymeric micellar paclitaxel (Pm-Pac) is safe and efficacious in advanced NSCLC patients. However, the histopathological-toxicological profile of Pm-Pac in mammals remains unclear. METHODS: We examined the Pm-Pac-induced antitumour effect in both A549/H226 cells and A549/H226-derived xenograft tumour models.. And then, we evaluated the short-term and long-term toxicity induced by Pm-Pac in healthy Sprague‒Dawley (SD) rats. The changes in body weight, survival, peripheral neuropathy, haematology, and histopathology were studied in SD rats administered Pm-Pac at different dosages. RESULTS: In the A549-derived xenograft tumour model, better therapeutic efficacy was observed in the Pm-Pac group than in the solvent-based paclitaxel (Sb-Pac) group when an equal dosage of paclitaxel was administered. Toxicity assessments in healthy SD rats indicated that Pm-Pac caused toxicity at an approximately 2- to 3-fold greater dose than Sb-Pac when examining animal body weight, survival, peripheral neuropathy, haematology, and histopathology. Interestingly, based on histopathological examinations, we found that Pm-Pac could significantly decrease the incidences of paclitaxel-induced brain and liver injury but could potentially increase the prevalence of paclitaxel-induced male genital system toxicity. CONCLUSION: This study introduces the toxicological profile of the engineered nanoparticle Pm-Pac and provides a novel perspective on the Pm-Pac-induced histopathological-toxicological profile in a rat model.