pH-sensitive carbon nanotubes graft polymethylacrylic acid self-assembly nanoplatforms for cellular drug release.

pH-Sensitive carbon nanotubes graft polymethylacrylic acid hybrids (CNTs-<i>g</i>-PMAA) were prepared through a three-step process, and self-assembled into core-shell micelle nanoparticles. The chemical structure of the hybrids were characterized by FTIR, ¹H NMR and TGA. The critical micelle concentration (CMC) was measured by surface tension, and the value hinged on the Mn values or chain lengths of PMAA segments. The UV-vis transmittance, dynamical light scattering (DLS), and <i>zeta</i> potential measurements indicated that the hybrid self-assembly exhibited pH-sensentive responsiveness. The self-assembly was used to load an anticancer drug, paclitaxel (PTX), with an encapsulation efficiency of 77%. The PTX-loaded hybrid drug preparations were applied for cancer-cellular drug release, finding that the release rate was dependent on pH environments, and faster in acidic media of pH &lt; 6.8 than in pH 7.4. MTT and hemolysis assays manifested that the blank hybrid drug carriers were nontoxic and safe, whereas the PTX-loaded drug preparations possessed comparable and even higher anticancer activity in comparison with free PTX. Consequently, the developed hybrid drug nanocarriers can be used for cancer therapy as a promising candidate.