Co-enhance bioactive of polymer scaffold with mesoporous silica and nano-hydroxyapatite

Abstract

Mesoporous silica Santa Barbara Amorphous-15 (SBA15) and nano-hydroxyapatite (nHA) were introduced in poly-l-lactic acid (PLLA) scaffold fabricated by selective laser sintering to co-enhance the bioactivity. On the one hand, the active elements silicon and calcium released respectively by the degradation of SBA15 and nHA were favorable for stimulating cell response. On the other hand, the hydrated silica gel layer derived from SBA15 could adsorb calcium ions released from nHA, thereby co-promoting apatite nucleation and growth. The experimental results showed that the formation of bone-like apatite on the scaffold was accelerated under simulated body fluid, indicating a good biomineralization capacity. Moreover, the scaffold demonstrated a good cell response in promoting the attachment of cell and the expression of alkaline phosphatase activity. Besides, SBA15 and nHA not only improved the hydrophilicity of the scaffold (the water contact angle changed from 107.4° to 57.8°), but also retarded the pH reduction by neutralizing the acidic hydrolysate of PLLA. These results indicated that the PLLA-SBA15-nHA scaffold may be potential candidates for bone repair.

Keywords:

• co-enhance
• bioactivity
• scaffold
• hydrophilicity
• nano-hydroxyapatite

Additional information

Funding

This study was supported by the following funds: (1) The Natural Science Foundation of China (81871494, 81871498, 51705540); (2) Hunan Provincial Natural Science Foundation of China (2018JJ3671, 2019JJ50588); (3) Guangdong Province Higher Vocational Colleges & Schools Pearl River Scholar Funded Scheme (2018); (4)The Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University; (5) The Project of Hunan Provincial Science and Technology Plan (2017RS3008); Shenzhen Science and Technology Plan Project (JCYJ20170817112445033); (6) National Postdoctoral Program for Innovative Talents (BX201700291); (7) The China Postdoctoral Science Foundation (2018M632983); (8) The Fundamental Research Funds for the Central Universities of Central South University (2018ZZTS145).