Laser-Patterned Diamond Electrodes for Adhesion and Proliferation of Human Mesenchymal Stem Cells

<p dir="ltr">The ability to form diamond electrodes on insulating polycrystalline diamond substrates using single-step laser patterning and the use of these electrodes as a substrate that supports the adhesion and proliferation of human mesenchymal stem cells (hMSCs) are demonstrated. Laser-induced graphitization results in a conductive amorphous carbon surface, rich in oxygen- and nitrogen-terminated groups. This leads to an electrode with a high specific capacitance of 182 μF cm², a wide water window of 3.25 V, and a low electrochemical impedance of 129 Ω cm² at 1 kHz—essential attributes for effective bioelectronic cell interfaces. The electrode's surface exhibits no cytotoxic responses with hMSCs, supporting cell adhesion and proliferation. Cells cultured on the electrode display significant elongation and alignment along the direction of the laser-patterned microgrooves—an additional modality for cellular modulation. The combination of favorable electrochemical performance and effective cellular control makes laser-patterned diamond electrodes a versatile platform in stem cell therapeutics. This direct fabrication approach paves the way for the integration of diamond electrodes in bioelectronic devices, offering new opportunities for tissue engineering and electroactive biomaterial applications.</p>