Biological Designer Self-Assembling Peptide Nanofiber Scaffolds Significantly Enhance Osteoblast Proliferation, Differentiation and 3-D Migration

Abstract

A class of self-assembling peptide nanofiber scaffolds has been shown to be an excellent biological material for 3-dimension cell culture and stimulating cell migration into the scaffold, as well as for repairing tissue defects in animals. We report here the development of several peptide nanofiber scaffolds designed specifically for osteoblasts. We designed one of the pure self-assembling peptide scaffolds RADA16-I through direct coupling to short biologically active motifs. The motifs included osteogenic growth peptide ALK (ALKRQGRTLYGF) bone-cell secreted-signal peptide, osteopontin cell adhesion motif DGR (DGRGDSVAYG) and 2-unit RGD binding sequence PGR (PRGDSGYRGDS). We made the new peptide scaffolds by mixing the pure RAD16 and designer-peptide solutions, and we examined the molecular integration of the mixed nanofiber scaffolds using AFM. Compared to pure RAD16 scaffold, we found that these designer peptide scaffolds significantly promoted mouse pre-osteoblast MC3T3-E1 cell proliferation. Moreover, alkaline phosphatase (ALP) activity and osteocalcin secretion, which are early and late markers for osteoblastic differentiation, were also significantly increased. We demonstrated that the designer, self-assembling peptide scaffolds promoted the proliferation and osteogenic differentiation of MC3T3-E1. Under the identical culture medium condition, confocal images unequivocally demonstrated that the designer PRG peptide scaffold stimulated cell migration into the 3-D scaffold. Our results suggest that these designer peptide scaffolds may be very useful for promoting bone tissue regeneration.

Charge transport and intrinsic fluorescence in amyloid-like fibrils

“…Apart from their pathological relevance, amyloid fibrils are one of several self-assembling peptide systems that are attracting increasing interest for applications ranging from molecular electronics (20,21) to tissue engineering and material science (22)(23)(24)(25)(26)(27). Metallic nanowires have been produced by different strategies on templates made from protein nanotubes and nanofibrils (20,21), and the possibility to control both the vertical and horizontal arrangements of the peptide nanotubes has been demonstrated recently (28).…”

Hydrogel depots for local co-delivery of osteoinductive peptides and mesenchymal stem cells

“…In pursuit for superior osteoinductive compounds for bone regeneration therapies, OGP has provided a useful basis for engineering additional OGP analogs with enhanced bioactivity, stability and bioavailability. This includes the design of different peptide sequences to be used in free soluble forms [8], as well as more complex systems with physically or chemically immobilized OGP for local administration [16][17][18]. In this context, the aim of this study was to develop protease-responsive delivery systems for OGP analogs, which could simultaneously act as injectable hMSCs vehicles, for minimally invasive healing of small bone defects.…”

Biomimetic Architectures for Tissue Engineering

“…Recently, the same group developed an arginine, alanine, aspartate, and alanine (RADA-16) sequence that assembled into three-dimensional hydrogels composed of www.intechopen.com nanofibrils ( Figure 5). The primary base sequences were additionally functionalized with an osteogenic growth peptide and two other cell adhesion motifs via direct solid phase extension of the C-termini (Horii, Wang et al 2007). Similarly, Silva et al incorporated a pentapeptide amino acid sequence (isolucinelysinevaline-alanine-valine, IKVAV onto a hydrocarbon tail (Silva, Czeisler et al 2004).…”