Bioceramics in the CaMgSi2O6–Li2O System: A Glass‐Ceramic Strategy for Excellent Mechanical Strength and Enhanced Bioactivity by Spontaneous Elemental Redistribution. Issue 12 (3rd March 2023)

• Record Type: Journal Article
• Authors: Tseng, Yu‐Sheng; Su, Yun‐Han; Chen, Chia‐Lin; Zhang, Ji; Wang, Chih‐Kuang; Hanaor, Dorian Amir Henry; Chen, Wen‐Fan
• Is Part Of: Advanced materials interfaces. Volume 10:Issue 12(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-03-03
• Subjects: bioactivities -- diopside -- lithium oxides -- mechanical properties; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.202202491
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract: A novel glass‐ceramic strategy for synthesizing mixed phase diopside (CaMgSi2 O6 )–lithium oxide (Li2 O) bioceramics with excellent mechanical strength, superior biodegradation resistance, low environmental pH impact, enhanced bioactivity, and reasonable biocompatibility is developed for biomedical applications. The substitution of Li2 O for MgO in CaMgSi2 O6 stimulates the formation of secondary phases: CaSiO3, Li2 Si2 O5, SiO2, Li2 SiO3, and Li2 Ca2 Si5 O13 . The evolution of CaSiO3 improves the surface hydroxyapatite (HAp) formation but lowers the mechanical strength and biological resistance, while the amorphous Li2 Si2 O5 phase tremendously reinforces the bioceramics by densifying the microstructure, indicating the simultaneous enhancement of bioactivity, mechanical strength, and durability. The promoted HAp formation is induced by the elemental redistribution where Mg elements are concentrated in large CaMgSi2 O6 grains embedded in Li2 Si2 O5 amorphous matrix, which hinders the Mg 2+ release and its readsorption by HAp. The cell viability is affected by Li2 O substitution because of the high‐dose Li + . In the current work, Li0.25 (25 mol% Li2 O) has the highest hardness (700 Hv as sintered and 197 Hv after simulated body fluid soaking), lowest weight loss (≈0.6 wt%), lowest pH variation (≈8.1), efficient HAp formation, and reasonable cell viability (70.5%), demonstrating its remarkable potential for bone implant applications due to the synergistic structural densification and biological improvement. Abstract : A novel glass‐ceramics strategy is developed in CaMgSi2 O6 –Li2 O system, which significantly enhances the bioactivity and mechanical strength of CaMgSi2 O6 ‐based bioceramics by the synergistic evolution of CaSiO3 and Li2 Si2 O5 amorphous matrix, while maintaining superior resistance and minimal pH impact in biological environment. The elemental redistribution hinders Mg 2+ release and prevents Mg 2+ entering hydroxyapatite (HAp) nuclei, leading to a promoted HAp formation.