The Use of a Green Fluorescent Protein Porcine Model to Evaluate Host Tissue Integration into Extracellular Matrix Derived Bionanocomposite Scaffolds

S E Smith,D A Grant,R A White,S A Grant

doi:10.1155/2015/586493

S E Smith, D A Grant + Show 2 more

Open Access

https://doi.org/10.1155/2015/586493

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Abstract

When using heterogeneous extracellular matrix (ECM) derived scaffolds for soft tissue repair, current methods of in vivo evaluation can fail to provide a clear distinction between host collagen and implanted scaffolds making it difficult to assess host tissue integration and remodeling. The purpose of this study is both to evaluate novel scaffolds conjugated with nanoparticles for host tissue integration and biocompatibility and to assess green fluorescent protein (GFP) expressing swine as a new animal model to evaluate soft tissue repair materials. Human-derived graft materials conjugated with nanoparticles were subcutaneously implanted into GFP expressing swine to be evaluated for biocompatibility and tissue integration through histological scoring and confocal imaging. Histological scoring indicates biocompatibility and remodeling of the scaffolds with and without nanoparticles at 1, 3, and 6 months. Confocal microscope images display host tissue integration into scaffolds although nonspecificity of GFP does not allow for quantification of integration. However, the confocal images do allow for spatial observation of host tissue migration into the scaffolds at different depths of penetration. The study concludes that the nanoparticle scaffolds are biocompatible and promote integration and that the use of GFP expressing swine can aid in visualizing the scaffold/host interface and host cell/tissue migration.

Highlights

The use of naturally derived biomaterials has become of increasing interest due to their superior performance over traditionally used synthetic materials [1]
Natural scaffolds materials are often derived from the extracellular matrix (ECM) that may help to evade the negative foreign body reaction of synthetic materials due to their biocompatible components
With an increasing amount of research on soft tissue repair materials comes the increased demand for better techniques to assess their in vivo performance

Summary

Introduction

The use of naturally derived biomaterials has become of increasing interest due to their superior performance over traditionally used synthetic materials [1]. If the components of the host tissue and scaffold material are very similar, they may appear similar when stained making small differences difficult to decipher This difficulty is especially true of larger, heterogeneous tissues such as the anterior tibialis tendon. Immunohistochemistry is another standard technique used [7, 8] the problem arises that most biomarkers such as collagen [9] that are present on the scaffold are present in the host tissue preventing distinction between the host tissue and scaffold. Another issue when utilizing fluorescence technology for visualization is naturally occurring autofluorescence of the scaffold as well as fixative-induced

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