Peptide-Capped Mesoporous Nanoparticles: Toward a more Efficient Internalization of Alendronate

Abstract

[EN] Osteoporosis is an illness which appears when the osteoblast/osteoclast activities are unbalanced taking place bone resorption (caused by osteoclasts) in higher extension than bone formation (induced by osteoblasts). Alendronate is one of the most used drugs for osteoporosis treatment despite its scarce bioavailability. Here we present the synthesis and characterization of mesoporous gated nanoparticles (two sets) for the controlled release of alendronate. The first set of nanoparticles (S1) were loaded with sulforhodamine B and capped with a peptide that could be selectively hydrolyzed by cathepsin K enzyme (overexpressed in osteoclasts). The second set (S2) was functionalized with aminopropyl moieties, loaded with nitrobenzofurazan labelled alendronate and capped with the same peptide. Both nanoparticles were internalized by RAW 264.7 macrophages (which could differentiate in osteoclasts) and were able to release its entrapped cargo in the presence of cathepsin K added in the macrophage lysates. Using S2 nanoparticles 4.2% of the total alendronate amount in contact with the cells is liberated inside them and could produce its therapeutic effect.