Electroactive BaTiO3 nanoparticle-functionalized fibrous scaffolds enhance osteogenic differentiation of mesenchymal stem cells

Abstract

Yiping Li,1,2 Xiaohan Dai,1 Yunyang Bai,2 Yun Liu,2 Yuehong Wang,1 Ousheng Liu,1 Fei Yan,1 Zhangui Tang,1 Xuehui Zhang,3–5 Xuliang Deng2,4,5 1Department of Prosthodontics, Xiangya Stomatological Hospital & School of Stomatology, Central South University, Changsha, 2Department of Geriatric Dentistry, 3Department of Dental Materials & Dental Medical Devices Testing Center, Peking University School and Hospital of Stomatology, 4National Engineering Laboratory for Digital and Material Technology of Stomatology, 5Beijing Laboratory of Biomedical Materials, Peking University School and Hospital of Stomatology, Beijing, People’s Republic of China Abstract: It has been proven that the surface topographic cues of fiber arrangement can induce osteogenic differentiation of mesenchymal stem cells. However, this effect alone is weak and insufficient to meet the needs of regenerative medicine. In this work, electroactivity concept was introduced to enhance the osteoinductivity of fibrous scaffolds. The randomly oriented and aligned electroactive fibrous scaffolds of poly-(L-lactic acid) (PLLA) with incorporation of ferroelectric ceramic BaTiO3 (BTO) nanoparticles (NPs) were fabricated by electrospinning. Physicochemical properties, including fiber morphology, microstructure, composition, thermal stability, surface roughness, and surface wettability, of these fibrous scaffolds were studied. The dielectric properties of the scaffolds were evaluated. The results showed that the randomly oriented BTO/PLLA composite fibrous scaffolds had the highest dielectric permittivity of 1.19, which is of the same order of magnitude as the natural bone. The combined effects of fiber orientation and electrical activity on the osteogenic responses of bone marrow mesenchymal stem cells (BM-MSCs) were specifically investigated. Randomly oriented composite fibrous scaffolds significantly promoted polygonal spreading and encouraged early osteogenic differentiation in BM-MSCs, whereas aligned composite fibrous scaffolds promoted cell elongation and discouraged osteogenic differentiation. These results evidenced that randomly fiber orientation and biomimetic electric activity have combining effects on osteogenic differentiation of BM-MSCs. Our findings indicate that coupling effects of multi-physical properties should be paid more attention to mimic the microenvironment for enhancing osteogenic differentiation of BM-MSCs. Keywords: topographic substrate, biomimetic electroactivity, ferroelectric ceramic, polarization, osteogenic responses

Keywords

• Topographic substrate
• Biomimetic electroactivity
• Ferroelectric ceramic
• Polarization
• Osteogenic responses.