Containerless fabrication of homogeneous-structure biomaterials with osteogenic and anti-inflammatory properties

Abstract

Current challenges in biomaterials center on a fundamental conflict between bioactivity and physiological homeostasis in material design. Inorganic biomaterials such as bioceramics and bioglasses exemplify this dilemma, as the release of functional ions is often accompanied by excessive alkalinization that limits practical use. We prepared a homogeneous lithium–calcium–silicate bioactive glass (LCS-CP) through containerless processing technique. LCS-CP maintained a mild alkaline microenvironment (pH < 8.0 in cell culture; < 9.2 in Tris–HCl over 50 days) and released substantially lower amounts of Li and Si than its crystalline counterpart (LCS-C) during 14-day cell culture, consistent with a more regulated bulk dissolution behavior. Although LCS-CP and melt-quenched glass (LCS-MQ) exhibited comparable averaged ion release and pH trends, LCS-CP showed more favorable interfacial outcomes, including more continuous and mature Ca–P deposition during time-resolved mineralization, which we attribute to its more homogeneous fully amorphous structure and uniformly distributed reactive sites. Functionally, LCS-CP promoted the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and mitigated neutrophil overactivation and pro-inflammatory factor secretion in vitro. In vivo, LCS-CP reduced early-stage inflammatory responses and supported tissue repair after implantation. Overall, this work demonstrates a containerless-processing route to develop bioactive materials with improved compatibility with homeostatic regulation.

Statement of significance

This work addresses a fundamental challenge in biomaterials: the conflict between bioactivity and physiological homeostasis. Lithium-calcium-silicate bioactive glass (LCS-CP) is developed using containerless processing, a technique that inhibits crystallization and creates a homogeneous, ion-rich structure. Unlike conventional materials, LCS-CP releases lithium, calcium, and silicon ions in a controlled manner to exert osteogenic and anti-inflammatory functions with a mild alkaline pH beneficial for tissue repair. It significantly enhances stem cell-based bone formation and suppresses neutrophil-driven inflammation. This study demonstrates that lithium-calcium-silicon homogeneous glass prepared by containerless processing can reconcile bioactivity with biosafety, offering a new strategy for designing adaptive biomaterials with broad significance in regenerative medicine.