RESUMEN
Supramolecular polymers allow for a modular approach to bioactive biomaterials. Here the effect of processing on the bioactivation of supramolecular biomaterials using a RNase S assay is investigated. Incorporation of S-peptides into supramolecular polymers by solvent casting shows a clear organic-solvent dependency. Although a significant release of the S-peptides is observed, RNase S activity can be measured indicating successful S-peptide surface immobilization. Additionally, the effect of electrospinning on the biomaterial's bioactivity is studied, showing that the fibrous meshes developed were bioactive. The results show the importance of solvent choice, and illustrate the potency of rendering supramolecular biomaterial films and meshes bioactive via a modular approach.
Asunto(s)
Péptidos/síntesis química , Poliésteres/síntesis química , Pirimidinonas/química , Ingeniería de Tejidos/métodos , Materiales Biocompatibles/síntesis química , Materiales Biocompatibles/química , Ensayo de Materiales , Microscopía de Fuerza Atómica , Nanofibras , Péptidos/química , Poliésteres/química , Ribonucleasas/química , Técnicas de Síntesis en Fase Sólida , Solventes , Propiedades de SuperficieRESUMEN
Maintenance of polarisation of epithelial cells and preservation of their specialized phenotype are great challenges for bioengineering of epithelial tissues. Mimicking the basement membrane and underlying extracellular matrix (ECM) with respect to its hierarchical fiber-like morphology and display of bioactive signals is prerequisite for optimal epithelial cell function in vitro. We report here on a bottom-up approach based on hydrogen-bonded supramolecular polymers and ECM-peptides to make an electro-spun, bioactive supramolecular mesh which can be applied as synthetic basement membrane. The supramolecular polymers used, self-assembled into nano-meter scale fibers, while at micro-meter scale fibers were formed by electro-spinning. We introduced bioactivity into these nano-fibers by intercalation of different ECM-peptides designed for stable binding. Living kidney membranes were shown to be bioengineered through culture of primary human renal tubular epithelial cells on these bioactive meshes. Even after a long-term culturing period of 19 days, we found that the cells on bioactive membranes formed tight monolayers, while cells on non-active membranes lost their monolayer integrity. Furthermore, the bioactive membranes helped to support and maintain renal epithelial phenotype and function. Thus, incorporation of ECM-peptides into electro-spun meshes via a hierarchical, supramolecular method is a promising approach to engineer bioactive synthetic membranes with an unprecedented structure. This approach may in future be applied to produce living bioactive membranes for a bio-artificial kidney.
Asunto(s)
Membrana Basal/citología , Membrana Basal/metabolismo , Túbulos Renales/citología , Riñón/citología , Riñón/metabolismo , Ingeniería de Tejidos/métodos , Células Cultivadas , Células Epiteliales/citología , Matriz Extracelular/química , HumanosRESUMEN
Ureido-pyrimidinone (UPy) dimers substituted with an additional urea functionality self-assemble into one-dimensional stacks in various solvents through lateral non-covalent interactions. (1)H NMR and DOSY studies in CDCl(3) suggest the formation of short stacks (<10), whereas temperature-dependent circular dichroism (CD) studies on chiral UPy dimers in heptane show the formation of much larger helical stacks. Analysis of the concentration-dependent evolution of chemical shift in CDCl(3) and the temperature-dependent CD effect in heptane suggest that this self-assembly process follows an isodesmic pathway in both solvents. The length of the aggregates is influenced by substituents attached to the urea functionality. In sharp contrast, UPy dimers carrying an additional urethane group do not self-assemble into ordered stacks, as is evident from the absence of a CD effect in heptane and the concentration-independent chemical shift of the alkylidene proton of the pyrimidinone ring in CDCl(3).