Advances in the slow freezing cryopreservation of microencapsulated cells

Abstract

Over the past few decades, the use of cell microencapsulation technology has been promoted for a wide range of applications as sustained drug delivery systems or as cells containing biosystems for regenerative medicine. However, difficulty in their preservation and storage has limited their availability to healthcare centers. Because the preservation in cryogenic temperatures poses many biological and biophysical challenges and that the technology has not been well understood, the slow cooling cryopreservation, which is the most used technique worldwide, has not given full measure of its full potential application yet. This review will discuss the different steps that should be understood and taken into account to preserve microencapsulated cells by slow freezing in a successful and simple manner. Moreover, it will review the slow freezing preservation of alginate-based microencapsulated cells and discuss some recommendations that the research community may pursue to optimize the preservation of microencapsulated cells, enabling the therapy translate from bench to the clinic.

Unveiling cells’ local environment during cryopreservation by correlativein situspatial and thermal analyses

“…To ascertain cell regrowth after freezing and thawing, 120 μl of each thawed solution was dispersed into 10 ml fresh YPD broth medium and incubated at 30 °C, 150 rpm. Aliquots were drawn at 8,12,24,28,32,48, 56 h and optical density at 600 nm was tracked using a UV spectrometer (UVIKONXL SECOMAM). Three replicates were performed for each ice front velocity.…”

Current Perspective and Advancements of Alginate-Based Transplantation Technologies

“…Cryopreservation, known as a viable option for tissue preservation and storage, can have severe effects on the viability and function of tissues during the freezing/thawing processes and from use of cryoprotective agents [66]. Alginate microcapsules have demonstrated the ability to maintain structure, slow cooling process, reduce effects of ice crystal formation on tissue, and regulate influx of cryoprotective agents during cryopreservation [67,68]. First used in preservation of plant cells, use of an alginate coating has been observed to have cryoprotective properties [69][70][71][72].…”

“…Transplantation research has particularly benefited from use of alginate technologies during cryopreservation. Recent studies in pancreatic islet transplantation have demonstrated that use of alginate microencapsulation helps maintain islet viability during preservation and improves islet secretory function during transplantation [67,78,79]. A 10 years study using encapsulated rat, pig, human islets showed that alginate encapsulated islets maintained significantly higher viability, secretory function, and yield compared to nonencapsulated islets after cryopreservation for 10 years [80].…”

Influencia de agentes crioprotectores sobre las cinéticas de congelación de lechuga (Lactuca sativa L.)

“…La crioprotección consiste en la adición previa a la congelación, de una sustancia que es capaz de incorporarse a las células del tejido o a los espacios intracelulares, protegiendo la textura del material vegetal del daño causado por los cristales de hielo (Gurruchaga et al 2018). Los crioprotectores son sustancias penetrantes o no penetrantes, de diferentes pesos moleculares, de baja toxicidad, que disminuyen el punto de congelación de una solución; con la aplicación de un crioprotector, las células estarán más deshidratadas y el gradiente osmótico al que estarán sometidas será menor (Pérez et al 2016).…”

“…Grandes progresos se lograron con el desarrollo de técnicas de crioprotección, identificándose este campo como un área de prioridad para la investigación, desarrollo y transferencias de tecnología. Se han llevado a cabo investigaciones que evalúan la capacidad de protección de células vegetales y animales de diferentes criopotectores (Marco & Serrano, 2012;Gurruchaga et al 2018). En tejido animal, se ha reportado el efecto crioprotector de oligopéptidos obtenidos de hidrolizado de merluza y de colágeno, con aplicaciones en la crioprotección de pescado y en la protección a la desnaturalización de la proteína de Surimi.…”