Roles of electrical stimulation in promoting osteogenic differentiation of BMSCs on conductive fibers

Abstract

The strategy of using conductive materials in regenerating bone defects is attractive, benefiting from the bioelectricity feature of natural bone tissues. Thereby, POP conductive fibers were fabricated by coating polypyrrole (PPY) onto electrospun poly(l‐lactide) (PLLA) fibers, and their potentials in promoting osteogenic differentiation of bone mesenchymal stromal cells (BMSCs) were investigated. Different from the smooth‐surfaced PLLA fibers, POP fibers were rough‐surfaced and favorable for protein adsorption and mineralization nucleation. When electrical stimulation (ES) was applied, the surface charges on the conductive POP fibers further promoted the protein adsorption and the mineral deposition, while the non‐conductive PLLA fibers displayed no such promotion. When BMSCs were cultured on these fibers, strong cell viability was detected, indicating their good biocompatibility and cell affinity. In osteogenic differentiation studies, BMSCs demonstrated the strongest ability in differentiating toward osteoblasts when they were cultured on the POP fibers under ES, followed by the case without ES. In comparison with the conductive POP fibers, the non‐conductive PLLA fibers displayed significantly weaker ability in inducing the osteogenic differentiation of BMSCs with ES being applied or not. Alongside the differentiation, both the calcium deposition on BMSC/material complexes and the intracellular Ca2+ concentration were identified the most abundant when BMSCs grew on the POP fibers under ES. These findings suggested that the surface charges of conductive fibers played roles in regulating protein adsorption, ion migration and nucleation, particularly under ES, which contributed much to the increased intracellular Ca2+ ions, and thus accelerated the osteogenic differentiation of the seeded cells. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.

Stimuli‐Responsive Biomaterials: Scaffolds for Stem Cell Control

“…Electrical stimulation of multipotent stem cells, specifically MSC and adipose stem cells (ASC), primarily are reported to enhance osteogenic differentiation, [98,120,123,125] as well as smooth muscle cells as investigated by Björninen et al [122] Zhang et al Figure 9. A) ALP activity on PPy-II electrodes with different Q inj and B) ALP activity on PPy-I and PPy-III electrodes with Q inj of 0.08 µC.…”

On the Interaction between 1D Materials and Living Cells

“…Electrical stimulation on conductive polymer fibres also allows promoting osteogenic differentiation of bone MSCs on conductive fibres as proved by Jing et al [ 199 ]. In particular, the authors fabricated conductive fibres by coating PPY onto electrospun PLLA fibres, obtaining conductive 1D materials with sub-micrometre sized diameters (960 ± 330 nm).…”

Antibacterial, conductive, and osteocompatible polyorganophosphazene microscaffolds for the repair of infectious calvarial defect

“…For bone regeneration, more importantly, conductive materials are electroactive to mimic the electrophysiological characteristics of native bone tissue, promoting osteogenesis via rebuilding the local endogenous electric field and modulating cellular behaviors 16 . For example, Jing et al prepared conductive fibers by coating PPy onto electrospun poly(lactide‐ co ‐glycolide) (PLGA) fibers, on which, bone marrow mesenchymal stromal cells (BMSCs) achieved higher expressions of alkaline phosphatase (ALP), type I collagen (COL‐I) and calcium deposition than those on PLGA fibers, particularly, when electrical stimulation was applied 17 . To avoid the use of nondegradable PANi and PPy, Liu et al blended aniline pentamer‐graft‐gelatin (AP‐ g ‐GA) with biodegradable poly( l ‐lactide) (PLLA) and electrospun electroactive AP‐g‐GA/PLLA nanofibers, which showed good cytocompatibility and were able to upregulate intracellular Ca 2+ expression 18 …”