Molecular weight and concentration of heparin in hyaluronic acid-based matrices modulates growth factor retention kinetics and stem cell fate

Abstract

Growth factors are critical for regulating and inducing various stem cell functions. To study the effects of growth factor delivery kinetics and presentation on stem cell fate, we developed a series of heparin-containing hyaluronic acid (HyA)-based hydrogels with various degrees of growth factor affinity and retention. To characterize this system, we investigated the effect of heparin molecular weight, fractionation, and relative concentration on the loading efficiency and retention kinetics of TGFβ1 as a model growth factor. At equal concentrations, high MW heparin both loaded and retained the greatest amount of TGFβ1, and had the slowest release kinetics, primarily due to the higher affinity with TGFβ1 compared to low MW or unfractionated heparin. Subsequently, we tested the effect of TGFβ1, presented from various heparin-containing matrices, to differentiate a versatile population of Sca-1+/CD45− cardiac progenitor cells (CPCs) into endothelial cells and form vascular-like networks in vitro. High MW heparin HyA hydrogels stimulated more robust differentiation of CPCs into endothelial cells, which formed vascular-like networks within the hydrogel. This observation was attributed to the ability of high MW heparin HyA hydrogels to sequester endogenously synthesized angiogenic factors within the matrix. These results demonstrate the importance of molecular weight, fractionation, and concentration of heparin on presentation of heparin-binding growth factors and their effect on stem cell differentiation and lineage specification.

Matrix metalloproteinase-13 mediated degradation of hyaluronic acid-based matrices orchestrates stem cell engraftment through vascular integration

“…HyA based hydrogels were synthesized using previously reported methods [6, 7, 33]. Briefly, HyA derivative carrying hydrazide groups (HyAADH) was synthesized using previously described methods[34–36], and acryloxysuccinimide (700 mg) was subsequently reacted to the HAADH solution (300mg, 100 mL DI water) to generate acrylate groups on the HyA (AcHyA)[36–38].…”

“…In view of these issues, we have proposed that Matrix-Assisted Cell Transplantation (MACT) might be used to promote pro-survival autocrine/paracrine signaling and to enhance engraftment [6, 7]. The design of synthetic matrices for cell transplantation includes biochemical and mechanical factors that promotes cell adhesion, proliferation, and differentiation, and stimulates engraftment of donor cells and tissue regeneration.…”

“…We employed a previously described HyA hydrogel system [6, 7], using high molecular weight HyA, a biopolymer with good biological performance that has been shown to also exhibit anti-inflammatory properties [30, 31]. This matrix contains the 15 amino-acid bone sialoprotein-derived peptide containing the Arg-Gly-Asp (RGD) sequence bsp-RGD (15) (CGGNGEPRGDTYRAY) for cell adhesion, high molecular weight heparin (HMWH) for exogenously added and endogenously synthesized growth factor presentation [6], and contains MMP-cleavable peptide linkages that allows MMP-dependent remodeling of the matrix. A population of Sca1 + /CD45 − /CD34 + /CD44 + cardiac progenitor cells (CPCs) that has demonstrated therapeutic capacity in a mouse ischemia model was used in our experiments [32].…”

“…Specifically, the presence of HMWH supports trophic functions of the CPCs by sequestering multiple endogenously secreted angiogenic factors within the matrix [6, 7, 33]. To test the effect of MMP degradation kinetics on CPC engraftment, three matrices were synthesized using the MMP-sensitive peptide crosslinkers (QPQGLAK, GPLGMHGK, and GPLGLSLGK) with significantly different degradation kinetics [25] (Table 1)(Fig.…”

Novel biomaterial strategies for controlled growth factor delivery for biomedical applications

“…5,42 Therefore, a number of biomaterials have been decorated with heparin or heparin sulfate-mimetic molecules, sequestering the heparin-binding ability of GFs to improve their delivery. For example, Jha et al 43 developed a series of heparin-functionalized hyaluronic acid-based hydrogels and investigated the effect of heparin molecular weight (MW) and its relative concentration on the loading efficiency and retention behavior of TGFβ1. The results demonstrated that high MW heparin facilitated TGFβ1 loading and retention and exhibited the slowest release kinetics, which was primarily due to its higher affinity for TGFβ1 compared to low MW heparin.…”