Biomaterial based strategies have been widely explored to preserve and restore the juvenile phenotype of cells of the nucleus pulposus (NP) in degenerated intervertebral discs (IVD). With aging and maturation, NP cells lose their ability to produce necessary extracellular matrix and proteoglycans, accelerating disc degeneration. Previous studies have shown that integrin or syndecan binding peptide motifs from laminin can induce NP cells from degenerative human discs to re-express juvenile NP-specific cell phenotype and biosynthetic activity. Here, we engineered alginate hydrogels to present integrin- and syndecan-binding peptides alone or in combination (cyclic RGD and AG73, respectively) to introduce bioactive features into the alginate gels. We demonstrated human NP cells cultured upon and within alginate hydrogels presented with cRGD and AG73 peptides exhibited higher cell viability, biosynthetic activity, and NP-specific protein expression over alginate alone. Moreover, the combination of the two peptide motifs elicited markers of the NP-specific cell phenotype, including N-Cadherin, despite differences in cell morphology and multicellular cluster formation between 2D and 3D cultures. These results represent a promising step toward understanding how distinct adhesive peptides can be combined to guide NP cell fate. In the future, these insights may be useful to rationally design hydrogels for NP cell-transplantation based therapies for IVD degeneration.

已广泛探索基于生物材料的策略来保存和恢复退化椎间盘 (IVD) 中髓核 (NP) 细胞的幼年表型。随着衰老和成熟，NP 细胞失去产生必要的细胞外基质和蛋白聚糖的能力，加速椎间盘退化。先前的研究表明，来自层粘连蛋白的整合素或syndecan结合肽基序可以诱导退化人类椎间盘中的 NP 细胞重新表达幼年 NP 特异性细胞表型和生物合成活性。在这里，我们设计了藻酸盐水凝胶单独或组合（分别为环状 RGD 和 AG73）呈递整合素和多聚体结合肽，以将生物活性特征引入藻酸盐凝胶中。我们证明了在海藻酸盐水凝胶上和内培养的人类 NP 细胞与单独的海藻酸盐相比，表现出更高的细胞活力、生物合成活性和 NP 特异性蛋白质表达。此外，两种肽基序的组合引发了 NP 特异性细胞表型的标志物，包括 N-钙粘蛋白，尽管在2D 和 3D 培养物之间的细胞形态和多细胞簇形成。这些结果代表了朝着了解如何结合不同的粘附肽来指导 NP 细胞命运迈出的有希望的一步。在未来，这些见解可能有助于合理设计水凝胶，用于基于 NP 细胞移植的 IVD 变性疗法。