Osteoinductive scaffolds composed of dual functionalized polylysine functionalized calcium phosphate graphene

Abstract

Bone regeneration remains a major clinical challenge due to limitations in the bioactivity, mechanical compatibility, and controlled resorbability of current interventions. Functional graphenic materials (FGMs) provide a tunable platform for bone-regenerative scaffolds, yet strategies to incorporate multiple bioactive functionalities while preserving their chemical and mechanical properties remain limited. Here, we developed a dual-functionalized calcium phosphate and poly(l-lysine) graphenic material (pKCaPG) designed to combine osteoinductive ion release with enhanced cell–material interactions. To accomplish this, poly(l-lysine) was grafted onto Claisen-modified graphene prior to calcium phosphate functionalization through an Arbuzov reaction, enabling sequential functionalization while preserving labile polyphosphate groups. Chemical characterization confirmed successful dual functionalization, while pKCaPG retained calcium and phosphate release comparable to calcium phosphate graphene and, with shorter poly(l-lysine) chains, maintained its compressive properties. In human bone marrow-derived mesenchymal stem cells, pKCaPG significantly increased alkaline phosphatase activity and mineral deposition relative to admixed controls and osteogenic media. Together, these results demonstrate that complementary bioactive functionalities can be integrated onto a graphenic scaffold without compromising key material properties and establish pKCaPG as a multifunctional platform for bone regeneration.