{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,19]],"date-time":"2026-10-19T08:41:40Z","timestamp":1792399300429,"version":"4.4.0"},"reference-count":39,"publisher":"American Association for the Advancement of Science (AAAS)","funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["82302395"],"award-info":[{"award-number":["82302395"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["spj.science.org"],"crossmark-restriction":true},"short-container-title":["Research"],"published-print":{"date-parts":[[2026,1,1]]},"abstract":"<jats:p>\n                    Microcurrent stimulation has emerged as a promising biophysical cue for cartilage regeneration, but its dose-dependent effects in 3-dimensional engineered cartilage constructs remain unclear. Here, we investigated the effects of continuous direct microcurrent stimulation on auricular chondrocytes and engineered cartilage spheroids using 0-, 10-, 25-, 50-, 100-, and 200-\u03bcA stimulation for 30 min daily. In 2-dimensional culture, microcurrent stimulation did not markedly increase the DNA content or Cell Counting Kit-8 value, indicating that it did not markedly promote cell expansion or overall metabolic activity. 5-Ethynyl-2\u2032-deoxyuridine and Ki67 assays showed that low to moderate (&lt;50 \u03bcA) stimulation had limited effects on proliferation, whereas 100 to 200 \u03bcA attenuated proliferative activity. Nevertheless, microcurrent stimulation enhanced chondrogenic marker expression in a biphasic manner, with type II collagen, SRY-box transcription factor 9, aggrecan, and cartilage oligomeric matrix protein increasing from 0 to 50 \u03bcA and declining from 50 to 200 \u03bcA. In 3-dimensional spheroids, 50 \u03bcA produced the most favorable morphology, cartilage-specific extracellular matrix deposition, mechanical properties, and hyaline cartilage-like phenotype. Excessive stimulation increased catabolic, inflammatory, and apoptosis-associated molecular responses without causing obvious cytotoxicity, apoptosis, reactive oxygen species production, temperature change, or pH alteration. Mechanistically, 50 \u03bcA induced coordinated Ca\n                    <jats:sup>2+<\/jats:sup>\n                    signaling and promoted nuclear factor of activated T cells (NFAT) nuclear translocation, whereas 200 \u03bcA generated dysregulated Ca\n                    <jats:sup>2+<\/jats:sup>\n                    responses and inefficient NFAT activation. Verapamil, 1,2-bis(2-aminophenoxy)ethane-\n                    <jats:italic toggle=\"yes\">N<\/jats:italic>\n                    ,\n                    <jats:italic toggle=\"yes\">N<\/jats:italic>\n                    ,\n                    <jats:italic toggle=\"yes\">N<\/jats:italic>\n                    \u2032,\n                    <jats:italic toggle=\"yes\">N<\/jats:italic>\n                    \u2032-tetraacetic acid acetoxymethyl ester, and cyclosporin A attenuated 50-\u03bcA-induced NFAT activation, supporting the involvement of the Ca\n                    <jats:sup>2+<\/jats:sup>\n                    \/calcineurin\/NFAT pathway. Furthermore, 50-\u03bcA-preconditioned spheroids showed superior cartilage-forming capacity after subcutaneous implantation. These findings identify 50 \u03bcA as a favorable bioelectrical stimulation condition within the tested intensity range and provide a practical strategy for enhancing cartilage spheroid maturation in cartilage tissue engineering.\n                  <\/jats:p>","DOI":"10.34133\/research.1462","type":"journal-article","created":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T06:57:41Z","timestamp":1790924261000},"update-policy":"https:\/\/doi.org\/10.34133\/aaas_crossmark_01","source":"Crossref","is-referenced-by-count":0,"title":["Effect of Microcurrent Stimulation on Cartilage Regeneration in Engineered Chondrocyte Spheroids"],"prefix":"10.34133","volume":"9","author":[{"given":"Yong","family":"Xu","sequence":"first","affiliation":[{"name":"Department of Thoracic Surgery, Shanghai Pulmonary Hospital, School of Medicine, \rTongji University, Shanghai, China."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Siqiang","family":"Zheng","sequence":"additional","affiliation":[{"name":"Department of Thoracic Surgery, Shanghai Pulmonary Hospital, School of Medicine, \rTongji University, Shanghai, China."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qiangsheng","family":"Hu","sequence":"additional","affiliation":[{"name":"Department of Thoracic Surgery, Shanghai Pulmonary Hospital, School of Medicine, \rTongji University, Shanghai, China."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-8569-2953","authenticated-orcid":true,"given":"Bo","family":"Tao","sequence":"additional","affiliation":[{"name":"Department of Thoracic Surgery, Shanghai Pulmonary Hospital, School of Medicine, \rTongji University, Shanghai, China."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"221","published-online":{"date-parts":[[2026,10,19]]},"reference":[{"issue":"28","key":"e_1_3_4_2_2","doi-asserted-by":"crossref","DOI":"10.1002\/advs.202521174","article-title":"Cascade-responsive MXene@Cu-MOF heterostructure integrates antioxidant activity, infection control, and vascularization for tracheal repair","volume":"13","author":"Guo L","year":"2026","unstructured":"Guo L, Shen Y, Yi J, Li J, Wang Z, Gao E, Zheng S, Chen Z-S, Tao B. Cascade-responsive MXene@Cu-MOF heterostructure integrates antioxidant activity, infection control, and vascularization for tracheal repair. Adv Sci. 2026;13(28): Article e21174.","journal-title":"Adv Sci"},{"key":"e_1_3_4_3_2","doi-asserted-by":"publisher","DOI":"10.34133\/research.0694"},{"issue":"47","key":"e_1_3_4_4_2","doi-asserted-by":"crossref","DOI":"10.1002\/advs.202514724","article-title":"Dual-pedicle tissue-engineered trachea promotes biomimetic cartilaginous framework, vascularization, and epithelial lining for long-segment tracheal reconstruction","volume":"12","author":"Wang Z","year":"2025","unstructured":"Wang Z, Wang Y, Chen Z, Gao E, Guo L, Li J, Zheng S, Yi J, Chen Z-S, Tao B. Dual-pedicle tissue-engineered trachea promotes biomimetic cartilaginous framework, vascularization, and epithelial lining for long-segment tracheal reconstruction. 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Advancements in chondrocyte 3-dimensional embedded culture: Implications for tissue engineering and regenerative medicine. Biom J. 2025;48(2): Article 100786.","journal-title":"Biom J"},{"key":"e_1_3_4_10_2","doi-asserted-by":"publisher","DOI":"10.1177\/20417314251349669"},{"issue":"1","key":"e_1_3_4_11_2","doi-asserted-by":"crossref","first-page":"32114","DOI":"10.1038\/s41598-024-83847-w","article-title":"Small spheroids for head and neck cartilage tissue engineering","volume":"14","author":"Reutter S","year":"2024","unstructured":"Reutter S, Kern J, Jakob Y, Rotter N, Gvaramia D. Small spheroids for head and neck cartilage tissue engineering. 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