Engineered 3D hydrogels with full-length fibronectin that sequester and present growth factors

Sara Trujillo,Cristina Gonzalez-Garcia,Patricia Rico,Andrew Reid,James Windmill,Matthew J Dalby,Manuel Salmeron-Sanchez

doi:10.1016/j.biomaterials.2020.120104

Abstract

Extracellular matrix (ECM)-derived matrices such as Matrigel are used to culture numerous cell types in vitro as they recapitulate ECM properties that support cell growth, organisation, migration and differentiation. These ECM-derived matrices contain various growth factors which make them highly bioactive. However, they suffer lot-to-lot variability, undefined composition and lack of controlled physical properties. There is a need to develop rationally designed biomaterials that can also recapitulate ECM roles. Here, we report the development of fibronectin (FN)-based 3D hydrogels of controlled stiffness and degradability that incorporate full-length FN to enable solid-phase presentation of growth factors in a physiological manner. We demonstrate, in vitro and in vivo, the effect of incorporating vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP2) in these hydrogels to enhance angiogenesis and bone regeneration, respectively. These hydrogels represent a step-change in the design of well-defined, reproducible, synthetic microenvironments for 3D cell culture that incorporate growth factors to achieve functional effects.

Highlights

In 3D culture, Extracellular matrix (ECM)-derived matrices, such as Matrigel, are currently widely used and support the growth and function of a wide variety of cell types in vitro, including the formation of organoids, cancer studies and cell engineering [1,2,3,4]
Using bone morphogenetic protein 2 (BMP2) and vascular endothelial growth factor (VEGF), we demonstrate the ability of this hydrogel system to recruit and retain growth factors (GFs) in vitro, thereby providing a novel 3D, functional environment with the potential to replace Matrigel, and to promote bone regeneration and vascularisation in vivo
FN monomers were PEGylated via a Michael-type addition reaction by functionalisation of the FN cysteine residues with a molar ratio FN monomer to 4-arm-poly(ethylene) glycol (PEG)-maleimide of 1–4 (Fig. S2)

Summary

Introduction

In 3D culture, ECM-derived matrices, such as Matrigel, are currently widely used and support the growth and function of a wide variety of cell types in vitro, including the formation of organoids, cancer studies and cell engineering [1,2,3,4]. Matrigel is an undefined mixture of ECM proteins and growth factors (GFs) obtained from EngelbrethHolm-Swarm mouse sarcoma cells [5]. Matrigel composition is undefined, lacking control of mechanical properties and subjected to lotto-lot variability. Biomaterials that have similar stiffness of the target tissue, degradability and that can present adhesion motifs and GFs with enhanced potency compared to soluble GFs, have yet to be identified. It is for this reason that Matrigel is widely used – as it contains proteins and GFs that provide biological activity not yet achieved by synthetic systems

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Discussion

Conclusion