Gelatin/Hyaluronic Acid Content in Hydrogels Obtained through Blue Light-Induced Gelation Affects Hydrogel Properties and Adipose Stem Cell Behaviors.

Shinji Sakai,Hiromi Ohi,Masahito Taya

doi:10.3390/biom9080342

Abstract

Composite hydrogels of hyaluronic acid and gelatin attract great attention in biomedical fields. In particular, the composite hydrogels obtained through processes that are mild for cells are useful in tissue engineering. In this study, hyaluronic acid/gelatin composite hydrogels obtained through a blue light-induced gelation that is mild for mammalian cells were studied for the effect of the content of each polymer in the precursor solution on gelation, properties of resultant hydrogels, and behaviors of human adipose stem cells laden in the hydrogels. Control of the content enabled gelation in less than 20 s, and also enabled hydrogels to be obtained with 0.5–1.2 kPa Young’s modulus. Human adipose stem cells were more elongated in hydrogels with a higher rather than lower content of hyaluronic acid. Stem cell marker genes, Nanog, Oct4, and Sox2, were expressed more in the cells in the composite hydrogels with a higher content of hyaluronic acid compared with those in the hydrogel composed of gelatin alone and on tissue culture dishes. These results are useful for designing conditions for using gelatin/hyaluronic acid composite hydrogels obtained through blue light-induced gelation suitable for tissue engineering applications.

Highlights

Biopolymers are polymers obtained from natural resources such as microorganisms and plants, and they are used in a wide range of applications
We studied the effect of the content of gelatin-Ph and hyaluronic acid (HA)-Ph on the viability, morphology, and stem marker expression of human adipose-derived stem cells (hASCs) enclosed inand gelatin-Ph/HA-Ph
These results demonstrate that blue light-induced gelation did not give a significant adverse effect that would induce cell death on the enclosed hASCs independent of the hydrogel composition

Summary

Introduction

Biopolymers are polymers obtained from natural resources such as microorganisms and plants, and they are used in a wide range of applications. Biocompatible biopolymers are excellent candidates to be used in pharmaceutical and medical applications including tissue engineering and regenerative medicine [1,2,3,4]. Gelatin and hyaluronic acid (HA) are biopolymers that have been historically prized for their usefulness in clinical fields [5,6,7]. In the tissue engineering field, their effectiveness for supporting growth and elevating biological functions of mammalian cells are well known [8,9,10]. Altering the ratio of polymers can cause a change in the mechanical properties of three-dimensional (3D) microenvironment surrounding the cells. It has been well recognized that cell behaviors, including the differentiation of stem cells, can be influenced by the mechanical

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Conclusion