In Vitro Neuronal Cell Culture: Challenges to Axon and Dendrite Growth and The Path Toward Neural Regeneration

Background: Neuronal cell culture provides unparalleled insights into developmental biology, disease modeling, and regenerative strategies; however, persistent obstacles—including limited neuronal longevity, tumorigenicity in stem cell–derived neurons, and reproducibility gaps—continue to impede translational progress. Methods: We critically review advances in extracellular matrix (ECM) engineering, three‑dimensional (3D) biomimetic microenvironments, molecular interventions, and standardization protocols, framing neuronal regeneration as a multidimensional optimization of mechanical, biochemical, and epigenetic variables. Results: 3D hydrogels with tunable stiffness and RGD motifs boost neurite outgrowth by 40%–60% over 2D cultures in primary neurons. Differential reliance on secretory pathway components (e.g., Sar1) underlies distinct axon versus dendrite growth, with dendritic extension reduced by ~70% upon Sar1 knockdown versus ~30% for axons. CRISPR‑Lin28 knockout in iPSC‑derived neurons reduces teratoma formation by ~60% in preclinical models. dCas9‑DNMT3A epigenetic editing silences inhibitory genes such as Nogo‑A with off‑target rates <10%. AI‑driven platforms (e.g., NeuroCult™) validated across five laboratories decrease protocol variability from 40%-12%. Conclusion: Integrating 3D biomimetic models, precise biochemical modulation, epigenetic tools, and standardized AI‑automated protocols offers a clear roadmap for bridging In vitro cultures with clinical translation for CNS injuries and neurodegenerative diseases.