Engineering Remyelination: Unlocking Oligodendrocyte Repair Through Medicine–Technology Convergence

Demyelinating diseases such as multiple sclerosis (MS) devastate the protective myelin sheath on axons, leaving neurons vulnerable to degeneration. Current therapies focus almost entirely on immunomodulation, that is, reducing inflammatory attacks, which has yielded major benefits in relapsing forms of MS, but these treatments do not restore lost myelin or halt the slow neurodegeneration of progressive MS [1]. Although several remyelination-promoting agents, such as clemastine, metformin, and opicinumab, have shown promise in animal models, most have exhibited limited efficacy in clinical trials or have been discontinued [2, 3]. To date, all approved treatments for multiple sclerosis act on the immune system, and no therapy has been demonstrated to directly promote remyelination in patients [4]. This leaves a critical unmet need: In chronic MS, demyelinated axons remain denuded and at risk of attrition despite controlled inflammation, manifesting as accumulated disability. Spontaneous remyelination can occur, especially early in disease, but it is often incomplete and ultimately fails as the disease progresses [5]. Lesion studies have shown that oligodendrocyte precursor cells (OPCs) are usually present even in chronic MS plaques, yet they do not efficiently mature into myelin-producing oligodendrocytes [6]. This oligodendrocyte precursor cell (OPC) differentiation bottleneck is a principal biological barrier to repair. Remyelination often stalls due to a combination of extrinsic and intrinsic barriers, as comprehensively reviewed by Gao et al. in this issue of Medicine Bulletin [7]. Chronically demyelinated lesions develop a hostile microenvironment with inhibitory signals from activated immune cells, reactive astrocytes, and accumulated debris [8, 9]. These cues block OPC recruitment and maturation. Moreover, chronically activated OPCs can acquire intrinsic deficits, including metabolic exhaustion, oxidative damage, and senescence, which reduce their regenerative capacity [8]. Notably, remyelination failure is more strongly correlated with failure of OPC differentiation than with the absence of OPC per se [10]. Overcoming these multilayered barriers requires an interdisciplinary convergence of biomedical science and engineering. Biomaterial scaffolds such as engineered hydrogels or matrices that mimic the brain's extracellular matrix can be tuned for stiffness and degradability to support OPC survival, migration, and differentiation [11]. Novel bioelectronic approaches, such as ultrasound-responsive piezoelectric hydrogels that wirelessly generate localized electrical stimulation and controlled molecular release, demonstrate how engineering-based interventions can actively shape the lesion microenvironment and enhance remyelination [7, 12]. Nanotechnology adds another layer of precision. For instance, nanoparticles loaded with leukemia inhibitory factor (LIF) and conjugated with anti-NG2 antibodies for OPC targeting significantly enhanced remyelination in vivo, improving both myelin thickness and fiber coverage [13]. All of these approaches circumvent the issues of cytokine degradation and off-target toxicity and highlight how smart nanocarriers can deliver spatiotemporally controlled signals based on biomedical science and engineering. Also, epigenetic engineering offers an emerging toolkit to reprogram OPCs. CRISPR-dCas9 systems have been used to silence differentiation inhibitors such as ID2 and ID4 via promoter methylation, effectively pushing OPCs toward myelinogenic fates [14]. In parallel, HDAC inhibitors (e.g., ESI1) and histone modulation strategies have shown promise in restoring age-impaired myelin repair [15]. Multiple promyelination and antimyelination signaling pathways offer engineerable “control points.” Wnt/β-catenin and Notch maintain OPCs in an undifferentiated state, whereas mTOR and thyroid hormone signaling promote maturation [8, 11]. Delivering pathway modulators via biomaterials or nanoparticles allows fine-tuning of the cellular response. Artificial intelligence is increasingly applied to model OPC dynamics, integrating transcriptomic and epigenetic data to identify synergistic transcription factors and therapeutic targets [11]. Looking ahead, smart delivery systems may adapt drug release to the inflammatory and biophysical state of central nervous system (CNS) lesions. For example, inflammation-responsive hydrogels have been proposed to adapt drug release to the inflammatory state of CNS lesions, potentially supporting remyelination strategies in multiple sclerosis [16, 17]. Biodegradable scaffolds or injectable matrices can release factors such as IGF-1, Noggin, or T3 in programmed waves, mimicking natural remyelination cues. Implantable hydrogels seeded with modified cells or nanoparticles could serve as localized regenerative hubs [11]. Personalized regenerative algorithms could integrate multimodal inputs such as MRI lesion topography, CSF proteomic markers, and OPC transcriptomes. Based on these datasets, the algorithms may generate individualized therapeutic outputs, including the optimal combination of regenerative factors, the timing and route of delivery, and the design of biomaterial scaffolds [7, 18, 19]. AI-guided combinatorial approaches tested in organoid models that recapitulate the lesion microenvironment may help pinpoint the most effective therapies by predicting optimal combinations of Wnt inhibitors, HDAC modulators, or mTOR activators based on lesion profiles to restore CNS repair capacity [20]. Critically, the future of remyelination therapy lies in converging medicine, materials science, and data systems. No single field can independently regenerate myelin. However, together, through interdisciplinary collaboration, we are beginning to unlock the CNS's repair potential—one engineered oligodendrocyte at a time. Chenhui Wang: writing – original draft. Chao Li: writing – original draft. Zhenglin Yang: review and final approval of the manuscript. Dr. Chenhui Wang and Dr. Zhenglin Yang serves as an Editor-in-Chief of Medicine Bulletin. Dr. Chao Li is the Managing Editor of Medicine Bulletin. This had no impact on the editorial assessment or the final decision of this article.