Aligned nanofibrous patch for sustained nicardipine delivery and enhanced chondrogenic differentiation in annulus fibrosus repair.

Intervertebral disc herniation is a leading cause of chronic low back pain, where the avascular nature of the disc limits nutrient transport to resident cells, resulting in cellular dysfunction and matrix degeneration. Enhancing vascular perfusion at the region has therefore emerged as a promising strategy to support disc repair. In this context, the present study aimed to develop a biomimetic, mechanically stable nanofibrous annulus fibrosus (AF) patch capable of sustained nicardipine delivery, while simultaneously supporting mesenchymal stem cell (MSC) viability and chondrogenic differentiation. For this, aligned and random poly(ϵ-caprolactone)/gelatin (75:25) nanofibrous patches were fabricated, with the hypothesis that scaffold architecture would influence both drug release behavior and cellular response. The results showed that the aligned fibers exhibited larger pore size and increased surface hydrophilicity compared to randomly oriented fibers. Nicardipine was efficiently encapsulated and released in a sustained manner over 21 d, with an additional late-stage increase in drug diffusion in aligned scaffolds.In vitroassessment using MSCs confirmed cytocompatibility, and markedly improved cell viability on aligned scaffolds. Overall, the findings demonstrate the potential of aligned, nicardipine-loaded PCL-gelatin nanofibrous AF patches as a dual-function platform for localized drug delivery and AF regeneration following discectomy. Further evaluation using native AF cells and relevantin vivomodels will be essential to determine long-term efficacy and safety.