Pancreatic Tissue-Derived Extracellular Matrix Bioink for Printing 3D Cell-Laden Pancreatic Tissue Constructs

Summary

Decellularized extracellular matrix (dECM) can provide suitable microenvironmental cues to recapitulate the inherent functions of target tissues in an engineered construct. This article elucidates the protocols for the decellularization of pancreatic tissue, evaluation of pancreatic tissue-derived dECM bioink, and generation of 3D pancreatic tissue constructs using a bioprinting technique.

Abstract

The transplantation of pancreatic islets is a promising treatment for patients who suffer from type 1 diabetes accompanied by hypoglycemia and secondary complications. However, islet transplantation still has several limitations such as the low viability of transplanted islets due to poor islet engraftment and hostile environments. In addition, the insulin-producing cells differentiated from human pluripotent stem cells have limited ability to secrete sufficient hormones that can regulate the blood glucose level; therefore, improving the maturation by culturing cells with proper microenvironmental cues is strongly required. In this article, we elucidate protocols for preparing a pancreatic tissue-derived decellularized extracellular matrix (pdECM) bioink to provide a beneficial microenvironment that can increase glucose sensitivity of pancreatic islets, followed by describing the processes for generating 3D pancreatic tissue constructs using a microextrusion-based bioprinting technique.

Introduction

Recently, pancreatic islet transplantation has been considered a promising treatment for patients with type 1 diabetes. The relative safety and minimal invasiveness of the procedure are great advantages of this treatment¹. However, it has several limitations such as the low success rate of isolating islets and the side effects of immunosuppressive drugs. Furthermore, the number of engrafted islets decreases steadily after transplantation due to the hostile environment². Various biocompatible materials such as alginate, collagen, poly(lactic-co-glycolic acid) (PLGA) or polyethylene glycol (PEG) have been applied to pancre....

Protocol

Porcine pancreatic tissues were collected from a local slaughterhouse. Animal experiments were approved by the Institutional Animal Care and Use Committee (IACUC) of Asan Medical Center, Seoul, Korea.

1. Tissue decellularization

1. Prepare the solutions for decellularization.
   NOTE: 1x phosphate-buffered saline (PBS) used in all solution preparations is diluted by adding distilled water to 10x PBS.
   1. For the 1% Triton-X 100 solution, dissolve 100 mL of 100% Triton-X 100 solution in 900 mL of 1x PBS using a magnetic stir bar with the stirring at 150 rpm for 6 h. Make 400 mL of 1% Triton-X 100 solution with 40 mL of 1....

Results

Decellularization of pancreatic tissues
We developed the process for preparing pdECM bioink to provide pancreatic tissue-specific microenvironments for enhancing functionality of islets in a 3D bioprinted tissue construct (Figure 2A). After the decellularization process, 97.3% of dsDNA was removed and representative ECM components such as collagen and GAGs remained at 1278.1% and 96.9% compared to that of the native pan.......

Discussion

This protocol described the development of pdECM bioinks and the fabrication of 3D pancreatic tissue constructs by using 3D cell printing techniques. To recapitulate the microenvironment of the target tissue in the 3D engineered tissue construct, the choice of bioink is critical. In a previous study, we validated that tissue-specific dECM bioinks are beneficial to promote stem cell differentiation and proliferation¹⁰. Compared to synthetic polymers, dECM can serve as a cell-favorable environment b.......

Materials

Name	Company	Catalog Number	Comments
Biological Safety Cabinets	CRYSTE	PURICUBE 1200
Deep Freezer	Thermo Scientific Forma	957
Digital orbital shaker	DAIHAN Scientific	DH.WSO04010
Dry oven	DAIHAN Scientific	WON-155
Freeze dryer	LABCONCO	7670540
Fridge	SANSUNG	CRFD-1141
Grater	ABM	1415605793
Inverted Microscopes	Leica	DMi1
Microcentrifuge	CRYSTE	PURISPIN 17R
Microplate reader	Thermo Fisher Scientific	Multiskan GO
Mini centrifuge	DAIHAN Scientific	CF-5
Multi-Hotplate Stirrers	DAIHAN Scientific	SMHS-6
Nanodrop	Thermo Fisher Scientific	ND-LITE-PR
pH benchtop meter	Thermo Fisher Scientific	STARA2110
Rheometer	TA Instrument	Discovery HR-2
Vortex Mixer	DAIHAN Scientific	VM-10
Cirurgical Instruments
Operating Scissors	Hirose	HC.13-122
Forcep	Korea Ace Scientific	HC.203-30
Materials
1.7 mL microcentrifuge tube	Axygen	MCT-175-C
10 ml glass vial	Scilab	SL.VI1243
40 µm cell strainer	Falcon	352340
5 L beaker	Dong Sung Science	SDS 2400
50 mL cornical tube	Falcon	352070
500 mL beaker	Korea Ace Scientific	KA.23-08
500 mL bottle-top vacuum filter	Corning	431118
500 mL plastic container	LOCK&LOCK	INL301
96well plate	Falcon	353072
Aluminum foil	DAEKYO
Kimwipe	Kimtech
Magnetic bar	Korea Ace Scientific	BA.37110-0003
Mortar and pestle	DAIHAN Scientific	SC.MG100
Multi-channel pipettor	Eppendorf	4982000314
Petri Dish	SPL	10100
pH indicator strips	Sigma-Aldrich	1095350001
Sieve filter mesh	DAIHAN Scientific
Decellularization
10x pbs	Hyclone	SH30258.01
4.7% Peracetic acid	Omegafarm
70% ethanol	SAMCHUN CHEMICALS	E0220 SAM
Distilled water
IPA	SAMCHUN CHEMICALS	samchun I0348
Triton-X 100	Biosesang	T1020
Biochemical assay
1,9-Dimethyl-Methylene Blue zinc chloride double salt	Sigma-Aldrich	341088
10 N NaOH	Biosesang	S2018
Chloramine T	Sigma-Aldrich	857319
Chondroitin sulfate A	Sigma-Aldrich	C4384
Citric acid	Supelco	46933
Cysteine-HCl	Sigma-Aldrich	C1276
Glacial acetic acid	Merok	100063
Glycine	Sigma-Aldrich	410225
HCl	Sigma-Aldrich	H1758
Na2-EDTA	Sigma-Aldrich	E5134
NaCl	SAMCHUN CHEMICALS	S2097
Papain	Sigma-Aldrich	p4762
P-DAB	Sigma-Aldrich	D2004
Perchloric acid	Sigma-Aldrich	311421
Sodium acetate	Sigma-Aldrich	S5636
Sodium hydroxide	Supelco	SX0607N
Sodium phosphate(monobasic)	Sigma-Aldrich	RDD007
Toluene	Sigma-Aldrich	244511
Bioink
Charicterized FBS	Hyclone	SH30084.03
Penicillin-Streptomycin	Thermo Fisher Scientific	15140122
Pepsin	Sigma-Aldrich	P7215
Rose bengal	Sigma-Aldrich	198250
RPMI-1640 medium	Thermo Fisher Scientific	11875093
Trypan Blue solution	Sigma-Aldrich	T8154