Composition of elastin like polypeptide–collagen composite scaffold influences in vitro osteogenic activity of human adipose derived stem cells

Abstract

Objectives Collagen-based scaffolds for guided bone regeneration (GBR) are continuously improved to overcome the mechanical weaknesses of collagen. We have previously demonstrated superior mechanical characteristics of the elastin-like polypeptide (ELP) reinforced collagen composites. The objectives of this research were to evaluate the efficacy of ELP-collagen composites to culture human adipose-derived stem cells (hASCs) and allow them to undergo osteogenic differentiation. We hypothesized that hASCs would show a superior osteogenic differentiation in stiffer ELP-collagen composites compared to the neat collagen hydrogels. Methods Composite specimens were made by varying ELP (0–18 mg/mL) and collagen (2–6 mg/mL) in a 3:1 ratio. Tensile strength, elastic modulus, and toughness were determined by uniaxial tensile testing. hASCs cultured within the composites were characterized by biochemical assays to measure cell viability, protein content, and osteogenic differentiation (alkaline phosphatase activity, osteocalcin, and Alizarin red staining). Scanning electron microscopy and energy dispersive spectroscopy was used for morphological characterization of composites. Results All composites were suitable for hASCs culture with viable cells over the 22-day culture period. The ELP-collagen composite with 18 mg/mL of ELP and 6 mg/mL of collagen had greater tensile strength and elastic modulus combined with higher osteogenic activity in terms of differentiation and subsequent mineralization over a period of 3 weeks compared to other compositions. The extra-cellular matrix deposits composed of calcium and phosphorous were specifically seen in the 18:6 mg/mL ELP-collagen composite. Significance The success of the 18:6 mg/mL ELP-collagen composite to achieve long-term, 3-dimensional culture and osteogenic differentiation of indicates its potential as a GBR scaffold.

Collagen‐Elastin‐Like Polypeptide‐Bioglass Scaffolds for Guided Bone Regeneration

“…In this study, we used a collagen‐ELP‐Bioglass hydrogel scaffold as a carrier of rat mesenchymal stem cells and assessed its in vitro and in vivo biocompatibility, in vivo degradation, and in vitro and in vivo bone regenerative effects. The specific components that we used for making the scaffold have been previously shown to be osteoconductive, osteoinductive (collagen, ELP) and osteostimulative (Bioglass) . In in vitro studies, the scaffolds remained stable for up to three weeks (Figure S2, Supporting Information, and Figure ), showing they have sufficient mechanical stability to support bone regeneration.…”

“…Our strategy to improve bone regeneration is to use a combination of natural, collagen‐ and elastin‐based polymers with a bioceramic to enhance cellular adhesion and integration with the host bone. While retaining the bulk properties of collagen, the mechanical tunability in our system is improved by adding components such as elastin‐like polypeptide (ELP, osteoconductive and osteoinductive) and 45S5 Bioglass (osteostimulative) . Through this approach, we have successfully improved the mechanical properties, physical characteristics (homogenous interconnected pore distribution and reduced swelling), and handling‐ability .…”

“…Through this approach, we have successfully improved the mechanical properties, physical characteristics (homogenous interconnected pore distribution and reduced swelling), and handling‐ability . We previously demonstrated that by increasing the stiffness of the scaffolds, in vitro osteogenic differentiation of human adipose‐derived stem cells (hASCs) and mouse preosteoblasts could be significantly enhanced . Here, we aimed to demonstrate the biocompatibility and utility of these composite scaffolds for in vivo bone regeneration in a rat model.…”

“…While retaining the bulk properties of collagen, the mechanical tunability in our system is improved by adding components such as elastin-like polypeptide (ELP, osteoconductive and osteoinductive) and 45S5 Bioglass (osteostimulative). [7][8][9][10] Through this approach, we have successfully improved the mechanical properties, physical characteristics (homogenous interconnected pore distribution and reduced swelling), and handling-ability. [7,8] We previously demonstrated that by increasing the stiffness of the scaffolds, in vitro osteogenic differentiation of human adipose-derived stem cells (hASCs) and mouse preosteoblasts could be significantly enhanced.…”

Biodegradable polymers for dental tissue engineering and regeneration

“…For example, Gurumurthy et al improved the mechanical characteristics of collagen through the use of elastin-like polypeptides. The obtained scaffold allowed osteogenic differentiation of human adipose-derived stem cells cultures [332]. Osteoblast growth and expression on these composite scaffolds were evaluated also by Amruthwar et al to validate the use of these devices on the treatment of alveolar bone loss [333].…”