Biomimetic Extracellular Matrix-Incorporated Scaffold Induces Osteogenic Gene Expression in Human Marrow Stromal Cells

Sriram Ravindran,Mrignayani Kotecha,Qi Gao,Richard L Magin,Sachin Karol,Anne George,Ana Bedran-Russo

doi:10.1089/ten.tea.2011.0136

Sriram Ravindran, Mrignayani Kotecha + Show 5 more

Open Access

https://doi.org/10.1089/ten.tea.2011.0136

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Abstract

Engineering biomaterials mimicking the biofunctionality of the extracellular matrix (ECM) is important in instructing and eliciting cell response. The native ECM is highly dynamic and has been shown to support cellular attachment, migration, and differentiation. The advantage of synthesizing an ECM-based biomaterial is that it mimics the native cellular environment. However, the ECM has tissue-specific composition and patterned arrangement. In this study, we have employed biomimetic strategies to develop a novel collagen/chitosan template that is embedded with the native ECM of differentiating human marrow stromal cells (HMSCs) to facilitate osteoblast differentiation. The scaffold was characterized for substrate stiffness by magnetic resonance imaging and nanoindentation and by immunohistochemical analysis for the presence of key ECM proteins. Gene expression analysis showed that the ECM scaffold supported osteogenic differentiation of undifferentiated HMSCs as significant changes were observed in the expression levels of growth factors, transcription factors, proteases, receptors, and ECM proteins. Finally, we demonstrate that the scaffold had the ability to nucleate calcium phosphate polymorphs to form a mineralized matrix. The results from this study suggest that the three-dimensional native ECM scaffold directly controls cell behavior and supports the osteogenic differentiation of mesenchymal stem cells.

Highlights

Regeneration or repair of native tissues requires scaffolds, appropriate cell types, and cell signaling molecules
Proof of extracellular matrix (ECM) deposition could be witnessed by scanning electron microscopy (SEM) analyses with evidence of matrix being deposited in the shape of a cell (Supplementary Fig. S2)
We show significant upregulation of osteogenic markers with human marrow stromal cells (HMSCs) cultured in the ECM scaffold, the results were obtained from a pool of HMSCs obtained from a single source

Summary

Introduction

Regeneration or repair of native tissues requires scaffolds, appropriate cell types, and cell signaling molecules. The desired cellular response is currently triggered by several approaches such as controlled release of signaling molecules, use of genetically engineered cells that constitutively express the desired factors, or coupling signaling molecules to the scaffolds.[1,2] These approaches have significant drawbacks such as inconsistent release kinetics, unpredictable diffusion rates of released molecules, risk of oncogenic transformation of transfected cells, and loss of activity of coupled molecules.[1,2] Often times, scaffolds are selected based on their ability to promote adhesion and proliferation of the desired cell types. Several of the scaffolds used for tissue engineering applications are derived from extracellular matrix (ECM) proteins or polymers designed to mimic ECM proteins, they do not mimic the native ECM, and in vivo-like behavior of the embedded cells cannot be obtained. To overcome the aforementioned drawbacks, the cellular response needs to be triggered by engineering a scaffold mimicking the extracellular environment of native tissue

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