Cell Adhesion-Mediated Piezoelectric Self-Stimulation on Polydopamine-Modified Poly(vinylidene fluoride) Membranes

Abstract

Cell adhesion-mediated piezoelectric stimulation provides a noninvasive method for in situ electrical regulation of cell behavior, offering new opportunities for the design of smart materials for tissue engineering and bioelectronic medicines. In particular, the surface potential is mainly dominated by the inherent piezoelectricity of the biomaterial and the dynamic adhesion state of cells. The development of an efficient and optimized material interface would have important implications in cell regulation. Herein, we modified the surface of poled poly­(vinylidene fluoride) (PVDF) membranes through polymerization of dopamine and investigated their influence on cell adhesion and electromechanical self-stimulation. Our results demonstrated that mesenchymal stem cells seeded on the poled PVDF membrane exhibited stronger cell spreading and adhesion. Meanwhile, the surface modification through polydopamine significantly improved the hydrophilicity of the samples and contributed to the formation of cell actin bundles and maturation of focal adhesions, which further positively modulated cell piezoelectric self-stimulation and induced intracellular calcium transients. Combining with theoretical simulations, we found that the self-stimulation was enhanced mainly due to the increase of the adhesion site and adhesion force magnitude. These findings provide new insights for probing the cell regulation mechanism on piezoelectric substrates, offering more opportunities for the rational design of piezoelectric biomaterial interfaces for biomedical engineering.

Integrated osteochondral differentiation of mesenchymal stem cells on biomimetic nanofibrous mats with cell adhesion-generated piezopotential gradients

“…Intracellular Ca 2+ was stained with Fluo-4 AM and imaged using a fluorescence microscope (FM Olympus IX83, Japan). 11 Briefly, after 24 h of culture on NFMs, culture media were removed, and Fluo-4 AM working solution (2 μM) was added to each well and cultured at 37 °C for 1 h. Then, the working fluid was replaced with serum-free media for 30 min to make Fluo-4 AM transform into Fluo-4. Fluo-4 combines with Ca 2+ to produce a strong green fluorescence, which was used to observe the intracellular Ca 2+ content.…”

“…During the cell-material interaction in a static environment, piezoelectric potentials are produced at the material surface by cellular autogenous adhesion forces, which will in turn stimulate and modulate cell activity. 11 The inherent piezoelectricity of the substrates and dynamic adhesion states of the cells determine the piezoelectric output. 37 Direct measurement of the cell-induced piezopotentials of NFMs is challenging.…”

“…10 Our recent study also demonstrated that cell adhesion produced piezoelectric potentials on modified PVDF substrates and further regulated the formation and maturation of cell actin, focal adhesions and intracellular calcium transients. 11 Despite these efforts, until now cell differentiation caused by cell adhesion-mediated self-stimulation on piezo polymeric scaffolds has been poorly studied.…”

Electrical Stimulation Enabled via Electrospun Piezoelectric Polymeric Nanofibers for Tissue Regeneration

“…Despite the application of direct ES, the external power and conductive connector are still inevitable. Recent developments of smart material have allowed the exertion of power-free ES with or without external stimulus [18][19][20]. Typically, the incorporation of triboelectric or piezoelectric material enables the self-powered therapeutic ES via harnessing passive human biomechanical energy [21][22][23].…”

Adhesive Capable of Underwater Adhesion and Wound Hemostasis Prepared Based on Solvent Exchange

“…There are two main methods for incorporate DA into polymer: (1) under basic aerobic conditions, the dehydrogenation reaction between the amino group of DA and the C 6 on the benzene ring leads to intermolecular cyclization, and then the cyclization product is further coupling to form a polydopamine (PDA) coating on the surface of the substrate; [ 28–30 ] 2) DA is grafted onto a polymer containing carboxyl groups through the dehydration condensation reaction of amino groups and carboxyl groups when N ‐hydroxysuccinimide and 1‐ethyl‐(3‐dimethylaminopropyl) carbodiimide hydrochloride salt (NHS‐EDC) is a catalyst. [ 31,32 ] However, PDA is mainly used for surface modification of materials, [ 33–35 ] and the grafting rate of DA is low if we incorporate DA into polymer by chemical cross‐linking method, [ 27,36 ] the result is materials cannot have enough catechol groups to achieve strong adhesion.…”