pH responsive release of paclitaxel by self-assembling Chitosan-ethyl vanillin@GNRs nanocomposites

• Published in: International journal of pharmaceutics 2021-09, Vol.607, p.121047-121047, Article 121047
• Main Authors: Fang, Ying, Wang, KangRui, Li, Qin, Huang, ChengHong
• Format: Article
• Language: English
• Subjects: Chitosan; Ethyl Vanillin; GNRs; pH responsive release
• ISSN: 0378-5173; 1873-3476
• DOI: 10.1016/j.ijpharm.2021.121047

Carboxylation chitosan achieved by Chloroactetic acid linked with ethyl vanillin to obtain Chitosan-ethyl vanillin (EV-CMCS). The EV-CMCS carried negative charges and will self-assemble into microsphere with approximately 760nm diameter. EV-CMCS loaded PTX will be released by positive charged gold nanorods. [Display omitted] •Carboxylated Chitosan-ethyl vanillin(EV-CMCS) was synthesized by Schiff base reaction.•Prepared Chitosan-ethyl vanillin (EV-CMCS) composite has a 760 nm in solution.•Loading capacitance and encapsulation rate of EV-CMCS for PTX is up to 19–38% and 60–81%.•EV-CMCS wrapped Paclitaxel can be pH responsively released by GNRs-triggering. Carboxylation chitosan achieved by alkalization linked with ethyl vanillin to obtain Chitosan-ethyl vanillin (EV-CMCS) compound through Schiff base reaction and confirmed by FT-IR, UV, XRD, TG and NMR. EV-CMCS refluxed with GNRs for acquisition of EV-CMCS@GNRs nanocomposites for PTX Loading and release. Results demonstrated that both EV-CMCS and EV-CMCS@GNRs are nanoscale composites with excellent solubilization due to their micelle structure taking CMC values of 0.06683 mg/mL and 0.06537 mg/mL. It was found that the loading and encapsulation rate of EV-CMCS and EV-CMCS@GNRs for PTX are 19.59~37.64% and 60.36~80.79% as well as 20.99~37.02% and 58.78~79.77%. Compared with only the delayed release of EV-CMCS that it have 11.5% and 18.7% accumulative release amount for 24 h and 14.9% and 23.7% for 48 h under both pH 6.8 and 7.4, the EV-CMCS@GNRs represent sudden release that it have an accumulative release amount of 90.2% for 24 h and 96.0% for 48 h at pH 6.8. It deduced that the broken Schiff base under acidic condition can increase CMC of EV-CMCS@GNRs, which offered an alternative way for paclitaxel delivery for tumor therapy.