Heparin-hyaluronic acid hydrogel in support of cellular activities of 3D encapsulated adipose derived stem cells

摘要

We have developed stem cell-responsive, heparin-hyaluronic acid (Hep-HA) hydrogel, crosslinked by thiolated heparin (Hep-SH) and methacrylated hyaluronic acid (HA-MA) via visible light mediated, thiol-ene reaction. Physical properties of the hydrogel (gelation time, storage modulus, and swelling ratio) were tunable by adjusting light intensity, initiator/polymer concentration, and precursor pH. Culture of human adipose derived mesenchymal stem cells (ADSCs) using this hydrogel was characterized and compared with the control hydrogels including Hep-PEG hydrogel, PEG-HA hydrogel. Sufficient initial adhesion and continuous proliferation of ADSCs in 2D were observed on both heparin-containing hydrogels (Hep-HA and Hep-PEG hydrogel) in contrast to no adhesion of ADSCs on PEG -HA hydrogel. On the other hand, in the case of 3D culture of encapsulated ADSCs, efficient cellular activities such as spreading, proliferation, migration, and differentiation of ADSCs were only observed in soft Hep-HA hydrogel compared to Hep-PEG or PEG -HA hydrogel with the similar modulus. The upregulated expressions of hyaluronidases in ADSCs encapsulated in Hep-HA hydrogel compared to the control hydrogels and effective degradation of the hydrogel by hyaluronidase imply that the degradation of hydrogel was necessary for 3D cellular activities. Thus, Hep-HA hydrogel, where heparin acts as a binding domain for ADSCs and HA acts as a degradation site by cell secreted enzymes, was efficient for 3D culture of human ADSCs without any additional modification using biological/chemical molecules.