Human Salivary Microtissues Enhance Human Salivary Stem/Progenitor Cell Behavior
Objectives: The biointegration potential for primary salivary human stem/progenitor cells (hS/PC) in humans is unknown. The salivary gland is a complex tissue with various stem/progenitor cells niches that maintain and repair the gland. We aimed to quantitatively determine host tissue effects on co-encapsulated hS/PCs in customizable hydrogel culture systems. We hypothesized that host tissue would influence the growth, differentiation, and organization of hS/PCs when co-encapsulated in the same hydrogel. Methods: Evaluation of paracrine and juxtacrine signaling between hS/PCs and host tissue was performed ex vivo in hyaluronic-acid based hydrogels. Fresh human salivary gland microtissues from parotid (hPG) or submandibular (hSMG) were co-encapsulated with hS/PC populations. Encapsulation groups included: 1) hPG or hSMG tissue only, 2) hS/PC only at 3x106 cells/mL, and 3) hPG or hSMG + hS/PCs at 2x106 cells/mL. Viability, hS/PC microstructure geometries and frequency were quantified from fluorescence confocal micrographs between days 10-20. Groups were assessed for biomarkers K14/p63 (stem), K19 (ductal), α-amylase (acinar), α-SMA (myoepithelial), and connexin proteins (connectivity). Results: All primary salivary gland microtissues and hS/PCs were viable. In the co-encapsulation groups, salivary microtissues and hS/PCs were not in direct contact. Co-encapsulation groups exhibited paracrine signaling that accelerated hS/PC growth rate and enhanced size and frequency of hS/PC microstructures when compared to hS/PC only groups (n=2). Co-encapsulated groups in MMP-sensitive hydrogels modified the permissive hydrogel and created direct contacts with organizing hS/PCs (n=3). Conclusions: Co-encapsulation of microtissues with hS/PCs is a culture model system that represents the potential behavior of therapeutically positioned hS/PCs in a human salivary bed. These first studies represent how host interactions positively influence hS/PCs in growth, growth rate and frequency. hS/PCs can differentiate into acinar, ductal, myoepithelial, and β3 tubulin expressing cells when encapsulated in our HA-based hydrogels indicating that hS/PCs can integrate with the host tissue when implanted.
Division: IADR/AADR/CADR General Session
Meeting:2019 IADR/AADR/CADR General Session (Vancouver, BC, Canada) Location: Vancouver, BC, Canada
Year: 2019 Final Presentation ID:0242 Abstract Category|Abstract Category(s):Salivary Research
Authors
Wu, Danielle
( University of Texas Health Science Center at Houston
, Houston
, Texas
, United States
)
Hubka, Kelsea
( Rice University
, Houston
, Texas
, United States
)
Martinez, Mariane
( Rice University
, Houston
, Texas
, United States
)
Viswanathan, Vignesh
( Stanford University
, Houston
, Texas
, United States
)
Witt, Robert
( University of Delaware
, Newark
, Delaware
, United States
)
Harrington, Daniel
( University of Texas Health Science Center
, Houston
, Texas
, United States
; Rice University
, Houston
, Texas
, United States
)
Le, Quynh-thu
( Stanford University
, Houston
, Texas
, United States
)
Farach-carson, Mary
( University of Texas Health Science Center at Houston
, Houston
, Texas
, United States
; Rice University
, Houston
, Texas
, United States
; Rice University
, Houston
, Texas
, United States
; University of Delaware
, Newark
, Delaware
, United States
)