Surface nitridation improves bone cell response to melt-derived bioactive silicate/borosilicate glass composite scaffolds

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• 作者：Felipe Orgaz^a ; Alexandra Dzika^a ; Olga Szycht^a ; Daniel Amat^b ; ^c ; Flora Barba^a ; José ; Becerra^d ; ^c ; ^e ; Leonor Santos-Ruiz^c ; ^e ; ^d ; ^{lsantos@uma.es" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Bioglasses ; Glass&ndash ; glass composite scaffolds ; Surface functionalization ; Ammonia nitridation ; Bone repair ; Bone regeneration ; Bone substitutes ; Tissue engineering ; Osteoblastic cell ; Cell adhesion ; Osteogenic differentiation
• 刊名：Acta Biomaterialia
• 出版年：2016
• 出版时间：1 January 2016
• 年：2016
• 卷：29
• 期：Complete
• 页码：424-434
• 全文大小：4004 K

文摘

Novel bioactive amorphous glass–glass composite scaffolds (ICIE16/BSG) with interconnected porosity have been developed. Hierarchically interconnected porous glass scaffolds were prepared from a mixture of two melt-derived glasses: a ICIE16 bioactive glass that was previously developed by Wu et al. (2011) to prevent crystallization, and a borosilicate glass of composition 73.48 SiO₂–11.35 B₂O₃–15.15 Na₂O (wt%). The resulting melt derived glass–glass composite scaffolds (ICIE16/BSG) were subject to surface functionalization to further improve its interaction with biological systems. Surface functionalization was performed by a nitridation process with hot gas N₂/ammonia at 550 °C for 2 h, obtaining the ICIE16/BSG-NITRI. Evaluation of the degradation rate and the conversion to hydroxyapatite after immersion in simulated body fluid predicted a good biological activity of all the scaffolds, but particularly of the nitrided ones. In vitro evaluation of osteoblastic cells cultured onto the nitrided and non-nitrided scaffolds showed cell attachment, proliferation and differentiation on all scaffolds, but both proliferation and differentiation were improved in the nitrided ICIE16/BSG-NITRI.

Statement of significance

Biomaterials are often required in the clinic to stimulate bone repair. We have developed a novel bioglass (ICIE16/SBG-NITRI) that can be sintered into highly porous 3D scaffolds, and we have further improved its bioactivity by nitridation. ICIE16/SBG-NITRI was synthesized from a mixture of two melt-derived glasses through combined gel casting and foam replication techniques, followed by nitridation. To mimic bone, it presents high-interconnected porosity while being mechanically stable. Nitridation improved its reactivity and bioactivity facilitating its resorption and the deposition of apatite (bone-like mineral) on its surface and increasing its degradation rate. The nitrided surface also improved the bioglass’ interaction with bone cells, which were found to attach better to ICIE16/SBG-NITRI and to differentiate earlier on its surface.