The development of smart biomaterials capable of modulating cell behavior through intrinsic electrical cues has gained significant attention in tissue engineering and bioelectronic medicine. In this study, we investigated the role of surface hydrophilicity and piezoelectricity in cell adhesion-mediated self-stimulation using polydopamine (PDA)-modified poled poly(vinylidene fluoride) (PVDF) membranes. PVDF membranes were fabricated via spin-coating and polarized under high voltage to induce the formation of the electroactive β-phase, resulting in strong piezoelectric properties. Subsequently, dopamine was polymerized on the membrane surface for varying durations (4–24 h) to generate PDA coatings, which significantly enhanced surface hydrophilicity without compromising the underlying piezoelectric response. Characterization by ATR-FTIR, XRD, and XPS confirmed the successful incorporation of PDA and the preservation of the β-phase content in poled samples. The water contact angle decreased from 130.9° to nearly 0° with extended polymerization time, indicating a transition to superhydrophilic surfaces. Atomic force microscopy revealed a moderate increase in surface roughness due to PDA deposition, while scanning electron microscopy showed a porous structure consistent with previous reports.
Mesenchymal stem cells (MSCs) were seeded onto PVDF-, PVDF+, PVDF-@PDA, and PVDF+@PDA membranes to evaluate their adhesive and morphological responses. Cells on hydrophobic PVDF- exhibited rounded shapes with minimal spreading, whereas those on poled PVDF+ showed slight elongation. Notably, MSCs cultured on PDA-modified substrates demonstrated significantly enhanced spreading, with increased cell area and aspect ratio. Fluorescence staining revealed well-developed actin bundles and mature focal adhesions on PVDF+@PDA membranes, indicating improved integrin clustering and cytoskeletal organization. Quantitative analysis confirmed that both the number and size of focal adhesions were approximately tenfold greater on PVDF+@PDA compared to PVDF-. These findings suggest that hydrophilic modification via PDA promotes stronger cell-substrate interactions, facilitating mechanical signal transduction.
To assess functional outcomes, intracellular calcium dynamics were monitored in real time using Fluo-4 AM dye. A significant proportion of cells on PVDF+@PDA membranes exhibited calcium transients (64%), compared to only 3% on non-piezoelectric PVDF- and 11% on PVDF-@PDA. This indicates that the combination of piezoelectricity and hydrophilicity enhances electromechanical feedback, likely through activation of stretch-activated or voltage-gated calcium channels. Finite element simulations further supported these observations: the piezoelectric potential output was primarily governed by the magnitude and number of adhesion sites rather than cell spreading area alone.58-14-0 supplier When adhesion force increased from 0.MTMR2 Antibody Purity & Documentation 1 to 30 nN, maximum potential rose linearly, while increasing adhesion site count from 4 to 8 significantly amplified the output.PMID:35092378 However, enlarging cell spread area without altering adhesion site number had negligible impact on surface charge distribution.
These results demonstrate that surface hydrophilicity plays a dominant role in enhancing cell adhesion-mediated piezoelectric self-stimulation. By promoting the formation of stable focal adhesions and increasing adhesion force, PDA modification enables more effective conversion of cellular traction forces into electrical signals. This mechanism provides a powerful strategy for designing intelligent biomaterial interfaces that dynamically regulate cell behavior through intrinsic biophysical cues. The findings offer new insights into the interplay between surface chemistry, mechanics, and bioelectricity, paving the way for rational design of next-generation piezoelectric scaffolds for regenerative medicine and implantable bioelectronics.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
