Tissue-Specific Effect Of An ECM Hydrogel On Salivary Gland Cells

Objectives: Salivary gland (SG) dysfunction significantly increases the risk of oral and dental disease(s), resulting in a compromised quality of life for those that are affected. Tissue engineering has the potential to restore SG function; however, there are gaps in our understanding regarding the role of the microenvironment (niche) in regulating SG cell growth. This study examined the effect of a tissue-specific hydrogel, derived from SG extracellular matrix (ECM), on SG cell growth.
Methods: A porcine submandibular gland hydrogel (pSMG-hydrogel) was prepared by decellularizing the tissue with either CHAPS buffer (8mM), containing NaCl(1.0M), EDTA(25mM) and proteinase inhibitors (Pierce), or buffered SDS(1%), followed by homogenization, lyophilization, pepsin(0.25%) digestion, and adjustment of the pH to neutrality. Hydrogel protein content was measured with the Bradford reagent; collagen content was assayed with the Sircol reagent. Par-C5 cells (a rat SG cell line) were cultured on pSMG-hydrogel-coated tissue culture plates (TCP). GFR-Matrigel®-coated and un-coated TCP plates were controls. Cell proliferation and expression of differentiation genes were monitored with AlamarBlue and RT-qPCR, respectively.
Results: We have successfully prepared a pSMG-hydrogel that can be used for cell culture. The growth curve of Par-C5 cells on the pSMG hydrogel coated plates was similar to that of the Matrigel®-coated and uncoated TCP. Par-C5 cells on the pSMG-hydrogel-coated plates expressed higher levels of cell differentiation biomarkers (i.e., acinar cell marker Mist1, tight junction marker claudin3, and secretory granule marker Prp15) as compared to cells on uncoated TCP. Biomarker expression was comparable on both the pSMG-hydrogel and Matrigel®.
Conclusions: A tissue-specific hydrogel, derived from porcine pSMG ECM, had similar effects on SG cell proliferation/growth and differentiation biomarker expression as tumor cell-derived Matrigel®. Our results suggest that the pSMG-hydrogel partially recapitulates the SG microenvironment and may be valuable for use in future SG tissue engineering or stem cell-based therapies for SG disorders.