Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, United States; Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, United States.
Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, United States; Department of Chemistry, Northwestern University, Evanston, IL 60208, United States.
Acta Biomater. 2024 Nov;189:103-115. doi: 10.1016/j.actbio.2024.09.047. Epub 2024 Oct 1.
Although autologous chondrocyte transplantation can be effective in articular cartilage repair, negative side effects limit the utility of the treatment, such as long recovery times, poor engraftment or chondrogenic dedifferentiation, and cell leakage. Peptide-based supramolecular polymers have emerged as promising bioactive systems to promote tissue regeneration through cell signaling and dynamic behavior. We report here on the development of a series of glycopeptide amphiphile supramolecular nanofibers with chondrogenic bioactivity. These supramolecular polymers were found to have the ability to boost TGFβ-1 signaling by displaying galactosamine moieties with differing degrees of sulfation on their surfaces. We were also able to encapsulate chondrocytes with these nanostructures as single cells without affecting viability and proliferation. Among the monomers tested, assemblies of trisulfated glycopeptides led to elevated expression of chondrogenic markers relative to those with lower degrees of sulfation that mimic chondroitin sulfate repeating units. We hypothesize the enhanced bioactivity is rooted in specific interactions of the supramolecular assemblies with TGFβ-1 and its consequence on cell signaling, which may involve elevated levels of supramolecular motion as a result of high charge in trisulfated glycopeptide amphiphiles. Our findings suggest that supramolecular polymers formed by the ultra-sulfated glycopeptide amphiphiles could provide better outcomes in chondrocyte transplantation therapies for cartilage regeneration. STATEMENT OF SIGNIFICANCE: This study prepares glycopeptide amphiphiles conjugated at their termini with chondroitin sulfate mimetic residues with varying degrees of sulfation that self-assemble into supramolecular nanofibers in aqueous solution. These supramolecular polymers encapsulate chondrocytes as single cells through intimate contact with cell surface structures, forming artificial matrix that can localize the growth factor TGFβ-1 in the intercellular environment. A high degree of sulfation on the glycopeptide amphiphile is found to be critical in elevating chondrogenic cellular responses that supersede the efficacy of natural chondroitin sulfate. This work demonstrates that supramolecular assembly of a unique molecular structure designed to mimic chondroitin sulfate successfully boosts chondrocyte bioactivity by single cell encapsulation, suggesting a new avenue implementing chondrocyte transplantation with supramolecular nanomaterials for cartilage regeneration.
虽然自体软骨细胞移植在关节软骨修复中可能有效，但负面副作用限制了该治疗的应用，例如恢复时间长、植入效果差或软骨细胞去分化以及细胞渗漏。基于肽的超分子聚合物已成为有前途的生物活性系统，可以通过细胞信号和动态行为促进组织再生。我们在这里报告了一系列具有软骨生成生物活性的糖肽两亲超分子纳米纤维的开发。这些超分子聚合物具有通过在其表面展示不同程度硫酸化的半乳糖胺部分来增强 TGFβ-1 信号的能力。我们还能够将这些纳米结构作为单细胞封装软骨细胞，而不会影响其活力和增殖。在所测试的单体中，三硫酸化糖肽的组装导致相对于模拟软骨素重复单元的低硫酸化程度的单体，软骨生成标志物的表达升高。我们假设增强的生物活性源于超分子组装与 TGFβ-1 的特定相互作用及其对细胞信号的影响，这可能涉及由于三硫酸化糖肽两亲物中的高电荷而导致的超分子运动水平升高。我们的研究结果表明，由超硫酸化糖肽两亲物形成的超分子聚合物可能为软骨再生的软骨细胞移植疗法提供更好的结果。
本研究制备了末端接有具有不同硫酸化程度的软骨素模拟残基的糖肽两亲物，它们在水溶液中自组装成超分子纳米纤维。这些超分子聚合物通过与细胞表面结构的紧密接触将软骨细胞封装为单细胞，形成人工基质，可将生长因子 TGFβ-1 定位在细胞外环境中。糖肽两亲物的高硫酸化程度对于提高软骨细胞的反应性至关重要，这种反应性超过了天然软骨素的功效。这项工作表明，设计用于模拟软骨素的独特分子结构的超分子组装通过单细胞封装成功地增强了软骨细胞的生物活性，为使用超分子纳米材料进行软骨细胞移植以进行软骨再生提供了新途径。
