Near-infrared responsive nanocomposite hydrogels made from enzyme-coated carbon nanotubes@ large pore mesoporous silica for remotely triggered drug delivery

Abstract

The design of smart nanocomposite supramolecular scaffolds for tissue engineering or anticancer applications, able to release drugs under external fields is currently a challenge. Such architectures require not only strong interactions between the polymer matrix and externally responsive nanomaterials, but also an efficient strategy for the loading and release of drugs. Herein, we address an original approach to trigger the self-assembly of peptide hydrogel from enzyme-coated carbon-based nanocomposites which act as initiators and cross-linking points of the resulting nanocomposite hydrogel. Carbon nanotubes (CNTs), chosen given their photothermal behavior under near infrared (NIR) light, were coated with large pore (>10 nm) mesoporous silica (CNT@LPMS) which are very suitable for a high loading of enzymes. Then, based on an original isobutyramide (IBAM)-mediated coating, a huge amount of alkaline phosphatase (AP) (>100% wt) was immobilized within the large pores allowing the localized growth of peptide nanofibrous network resulting in supramolecular hydrogel. The incorporation of Doxorubicin (DOX) during the hydrogelation process leads to a reservoir material of anti-cancer agents whose release is photothermally triggered by the NIR light-induced hyperthermia temperature. Combination of rheological studies and molecular simulations indicate an original mechanism in which DOX is included within the peptide nanofibers.