Lipid-Coated Mesoporous Silica Particles for pH-Sensitive Tumor-Targeted Paclitaxel: Development, Characterization

Nanoparticle carriers can selectively deliver the drug cargo to tumor cells, thus having the ability to prevent early drug release, reduce non-specific cell binding, and prolong <i>in vivo</i> drug retention. We constructed paclitaxel (PTX)-loaded lipid-shell mesoporous silica nanoparticles (LMSNs) for targeted anti-cancer drug delivery. The physical properties of PTX-LMSNs were analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The drug loading <i>(DL</i>%) and entrapment efficiency (<i>EE</i>%) of PTX-LMSNs were measured by high performance liquid chromatography (HPLC). <i>In vitro</i> drug release test, <i>in vivo</i> imaging, tissue distribution and pharmacokinetics of PTX-LMSNs were also evaluated. The SEM examination showed that MSNs were sphere, whereas TEM showed that they were rich in fine pores. The uniform core-shell structure of PTX-LMSNs was also verified by TEM. The DL capacity of PTX-LMSN was as high as 21.75%, and PTX was released from the nanoparticles <i>in vitro</i> in a pH-dependent manner. The cumulative amount of free PTX increased at lower pH, which is conducive to selective drug release from LMSNs in the acidic tumor tissues. <i>In vivo</i> imaging showed prolonged retention of PTX-LMSNs, which is beneficial to their therapeutic efficacy. In addition, PTX-LMSNs were primarily concentrated in the liver. Pharmacokinetic experiments showed that the half-life of PTX-LMSNs was 23.21% longer and 79.24% higher than that of Taxol. Together, LMSNs are a highly promising antineoplastic drug carrier system.