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

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.