Evaluation of dehydrated human umbilical cord biological properties for wound care and soft tissue healing

Abstract

Chronic wounds are a significant health care problem with serious implications for quality of life because they do not properly heal and often require therapeutic intervention. Amniotic membrane allografts have been successfully used as a biologic therapy to promote soft tissue healing; however, the umbilical cord, another placental-derived tissue, has also recently garnered interest because of its unique composition but similar placental tissue origin. The aim of this study was to characterize PURION® PLUS Processed dehydrated human umbilical cord (dHUC) and evaluate the biological properties of this tissue that contribute to healing. This was performed through the characterization of the tissue composition, evaluation of in vitro cellular response to dHUC treatment, and in vivo bioresorption and tissue response in a rat model. It was observed that dHUC contains collagen I, hyaluronic acid, laminin, and fibronectin. Additionally, 461 proteins that consist of growth factors and cytokines, inflammatory modulators, chemokines, proteases and inhibitors, adhesion molecules, signaling receptors, membrane-bound proteins, and other soluble regulators were detected. Cell-based assays demonstrated an increase in adipose-derived stem cell and mesenchymal stem cell proliferation, fibroblast migration and endothelial progenitor cell vessel formation in a dose-dependent manner after dHUC treatment. Lastly, rat subcutaneous implantation demonstrated biocompatibility since dHUC allografts were resorbed without fibrous encapsulation. These findings establish that dHUC possesses biological properties that stimulate cellular responses important for soft tissue healing. © 2018 The Authors. Journal Of Biomedical Materials Research Part B: Applied Biomaterials Published By Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1035-1046, 2019.

Keywords: Wharton's jelly; chronic wounds; dehydrated human umbilical cord; umbilical cord; wound healing.

© 2018 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials published by Wiley Periodicals, Inc.

Figures

Figure 1

Immunofluorescence staining of dHUC grafts. (A) Type I collagen presence seen in green. (B) HA distribution in the tissue visible in red. (C) Cell nuclei are shown in blue. (D) The overlay shows the co‐localization of hyaluronic acid (red) and cell nuclei (blue) in pink. Scale bar = 400 μm.

Figure 2

Protein composition of dehydrated human umbilical cord lysates. For each category, percentages reported represent the protein concentration (pg factor/mg tissue) normalized to the total protein amount detected.

Figure 3

Proliferation of (A) ADSCs and (B) MSCs after 72 h in response to dHUC treatments. Bars represent the average number of cells per well normalized to the Negative Control (red line) ± standard deviation detected in each treatment and control wells. * indicates statistically significant difference from Negative Control; # indicates statistical difference from Positive Control; p ≤ 0.05.

Figure 4

Phase images of (A) ADSCs and (B) MSCs at 72 h in response to control and dHUC treatments at 20, 10, 5, and 1 mg/mL. Scale bar = 300 μm.

Figure 5

Migration of HDFs over 72 h in response to dHUC treatment (20 mg/mL) and Positive and Negative Controls. Values are reported as mean relative wound confluence (%) ± standard deviation. * indicates statistically significant difference from positive and negative controls at 72 h; p ≤ 0.05.

Figure 6

Angiogenic response from ECFCs after dHUC treatments. (A) Average network length (mm/mm2) and (C) average network area (mm2/mm2) in response to dHUC extracts and controls over 72 h. (B) Network length and (D) network area at 72 h time point. Error bars represent the standard deviation from the mean values. * indicates statistical difference from all other groups; # indicates statistical difference from the positive control; Δ indicates statisical difference from the assay media only; p ≤ 0.05.

Figure 7

Fluorescent images of tagged endothelial cells (green) with positive, negative vehicle control treatments and dHUC treatments at 10, 5, and 1 mg/mL at 72 h. Scale bar = 500 μm.

Figure 8

Biocompatibility and bioresorption of dHUC allografts in a rat subcutaneous implant model at (A) 24 h, (B) 7 days, (C) 14 days, (D) 22 days, (E) 42 days, and (F) 97 days. Images on the left were stained with Movat's Pentachrome (collagen is yellow, cell nuclei are black/purple, glycosaminoglycans are light blue, muscle and fibrin are red, and elastin is black) and images on the right were stained with hematoxylin and eosin. Scale bar = 100 μm.

Figure 9

Histologic scoring for overall inflammation and residual implant material. Values reported as mean scoring ± standard deviation. ^ indicates scores that are only based on one sample because material could not be located in other animals.