Fabrication of Amyloid-Beta-Releasing Polymer Microbeads for Modeling Alzheimer's Disease

Abstract

Source: Almari, B., et al. Fabrication of Amyloid-β-Secreting Alginate Microbeads for Use in Modelling Alzheimer's Disease. J. Vis. Exp. (2019).

This video demonstrates a method for fabricating polymer microbeads that encapsulate neurotoxic amyloid-beta-secreting cells. The cell-polymer suspension is processed through a microbead fabrication device, with polymer gelation achieved via calcium cross-linking, forming spherical microbeads around the cells. The polymer allows cell proliferation while allowing controlled, long-term amyloid-beta release, simulating its accumulation in Alzheimer's disease.

Protocol

1. Preparations

1. Prepare 100 mL of ~4% (w/v) alginate stock solution.
   1. Weigh 4.4 g of alginate sodium salt and add the dry powder to 100 mL of HEPES-buffered saline (HBS, 20 mM hydroxyethylpiperazine ethane sulfonic acid [HEPES] (0.477 g) with 150 mM NaCl (0.877 g) in deionized water allowing hydration.
   2. Use a magnetic stirrer at ~500 revolutions per minute (rpm) and heat up to 50 °C to allow complete alginate hydration.
      NOTE: The alginate may need one or two hours to be completely hydrated. To save time, alginate solution can be made up a day in advance of the encapsulation protocol and st....

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
0.22 um PES filter	Merck, UK	SLGP033RS
15mm Netwell insert 74 um mesh filter	Constar, usa	#3477
Alginic acid sodium salt from brown algae	Sigma-Aldrich,uk	A0682
Calcium chloride	Sigma-Aldrich,uk	C1016
CellTiter96 AQueous One Solution cell proliferation assay	Promega, USA	G3580
Encapsulator	Inotech	IE-50	serial no. 05.002.01-2005
HEPES	Sigma-Aldrich,uk	H4024
Phosphate buffered saline	Sigma-Aldrich,uk	D1408
Sodium chloride	Sigma-Aldrich,uk	433209
Trispdium citrate dihydrate	Sigma-Aldrich,uk	W302600-K
Trypsin-EDTA solution	Sigma-Aldrich,uk	T4049