Luminescent Lanthanide-Collagen Peptide Framework for pH-Controlled Drug Delivery.

Abstract

Collagen mimetic scaffolds play a pivotal role in regenerative medicine and tissue engineering due to their extraordinary structural and biological features. We have herein, for the first time, reported the construction of luminescent lanthanide-collagen peptide hybrid three-dimensional nanofibrous scaffolds, which well mimic the characteristic architectural structure of native collagen. Three collagen mimetic peptides, composed of repetitive central (GPO)7 sequences and altered terminal amino acids, have been shown to consistently self-assemble to form biocompatible nanofibers under the trigger of a variety of lanthanide ions, which also functionalize the assembled materials with easily tunable photoluminescence. Furthermore, the collagen peptide-lanthanide hybrid scaffolds possess programmable pH-responsive features. The lanthanide ion-mediated assembly of all three collagen peptides are conveniently and reversibly regulated by pH, while their pH-dependent patterns are finely tuned by the identity of terminal amino acids. Using camptothecin and cefoperazone sodium as two model drugs, the drug-loading and releasing efficiency of the collagen peptide-lanthanide scaffolds are nicely modulated by pH, demonstrating the efficacy of these nanofibrous scaffolds as pH-responsive drug carriers. These novel luminescent collagen peptide-lanthanide scaffolds provide a facile system for pH-controlled drug delivery, suggesting promising applications in the development of therapies for many diseases.