Co-assembling peptides as defined matrices for endothelial cells

Abstract

Self-assembling peptides and peptide derivatives bearing cell-binding ligands are increasingly being investigated as defined cell culture matrices and as scaffolds for regenerative medicine. In order to systematically refine such scaffolds to elicit specific desired cell behaviors, ligand display should ideally be achieved without inadvertently altering other physicochemical properties such as viscoelasticity. Moreover, for in vivo applications, self-assembled biomaterials must exhibit low immunogenicity. In the present study, multi-peptide co-assembling hydrogels based on the beta-sheet fibrillizing peptide Q11 (QQKFQFQFEQQ) were designed such that they presented RGDS or IKVAV ligands on their fibril surfaces. In co-assemblies of the ligand-bearing peptides with Q11, ligand incorporation levels capable of influencing the attachment, spreading, morphology, and growth of human umbilical vein endothelial cells (HUVECs) did not significantly alter the materials' fibrillization, beta-turn secondary structure, or stiffness. RGDS-Q11 specifically increased HUVEC attachment, spreading, and growth when co-assembled into Q11 gels, whereas IKVAV-Q11 exerted a more subtle influence on attachment and morphology. Additionally, Q11 and RGDS-Q11 were minimally immunogenic in mice, making Q11-based biomaterials attractive candidates for further investigation as defined, modular extracellular matrices for applications in vitro and in vivo.

Redox modulated hydrogelation of a self-assembling short peptide amphiphile

“…Peptide hydrogels have been actively exploited for a variety of biomedical applications such as cell culture, regenerative medicine, controlled drug and gene delivery [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Most peptide hydrogels arise from the entanglement of selfassembled nanoobjects such as nanofibers and nanotubes.…”

Self-Assembled Peptides: Characterisation and In Vivo Response

“…There are also issues of reproducibility in regards to protein content that will have a direct impact on cell function. The use of self-assembling peptide scaffolds avoids this limitation, as they have no batch-to-batch variability, and the stepwise manner of their synthesis allows the incorporation of bioactive moieties [19][20][21]. In addition, they have a long shelf life being stable at room temperature for many years, which is critical for translation to the clinic.…”

“…Robust mechanisms have been developed for the formation of nanoscale spheres, fibres, sheets and tubes. These include: complementary peptide repeats which utilise complementary charges to self-organise [29]; glutamine rich sequences [20]; peptide-amphiphiles, where a hydrophobic alkyl tail is attached to a peptide driving tubular micelle formation [33]; aromatic N-terminally capped peptides or aromatic residues which take advantage of p-stacks or aromatic motifs [5,32]; proline containing hairpin forming oligopeptides [34]; and a-helical coiled coil peptides utilising the self recognition inherent in leucine zippers [35] (see Table 1 and Fig. 2 for more examples).…”

“…The presentation of RGD has also been observed to be a function of the aromatic sidechains flanking the epitope, where fmoc-RDGF has a greater bioavailability than fmoc-FRGD, possibly through increased rigidity provided by the aromatic residue at the C terminal [45]. When the RGD peptide was included as a pendant molecule on an oligopeptide, the biological response was increased without disrupting the mechanism of assembly as the pendant signal was not integral to the assembly process [20]. Incorporating bioactive sequences Reprinted from Ref.…”

Bioinspired Strategies for Hard Tissue Regeneration

“…RAD16 peptide which is derived from the self-assembling sequences of laminin is a -sheet fibril forming peptide that is capable of presenting bioactive ligands on their surface (44)(45)(46). Q11 a peptide containing the sequence (QQKFQFQFEQQ) was designed to present ligands such as RGDS or IKVAV at their N-termini (47). The RGDS sequence found in fibronectin, laminin, vitronectin and many other extracellular matrix proteins is an integrin binding peptide and is neutrally charged and hydrophilic (48).…”