Interaction of preservation methods and radiation sterilization in human skin processing, with particular insight on the impact of the final water content and collagen disruption. Part I: process validation, water activity and collagen changes in tissues cryopreserved or processed using 50, 85 or 98% glycerol solutions

M R Herson; K Hamilton; J White; D Alexander; S Poniatowski; A J O'Connor; J A Werkmeister

doi:10.1007/s10561-018-9694-1

Interaction of preservation methods and radiation sterilization in human skin processing, with particular insight on the impact of the final water content and collagen disruption. Part I: process validation, water activity and collagen changes in tissues cryopreserved or processed using 50, 85 or 98% glycerol solutions

Cell Tissue Bank. 2018 Jun;19(2):215-227. doi: 10.1007/s10561-018-9694-1. Epub 2018 Apr 25.

Authors

M R Herson¹, K Hamilton², J White³, D Alexander⁴, S Poniatowski², A J O'Connor⁵, J A Werkmeister⁶

Affiliations

¹ Department of Surgery - Central Medical School, Monash University, Melbourne, Australia. herson.marisa@gmail.com.
² Donor Tissue Bank of Victoria - Victorian Institute of Forensic Medicine, Melbourne, Australia.
³ CSIRO - Manufacturing, Clayton, Australia.
⁴ CSIRO - Data 61, Clayton, Australia.
⁵ Department of Chemical and Biomolecular Engineering, University of Melbourne, Melbourne, Australia.
⁶ Hudson Institute of Medical Research, Monash University, Clayton, Australia.

PMID: 29696490
DOI: 10.1007/s10561-018-9694-1

Abstract

Current regulatory requirements demand an in-depth understanding and validation of protocols used in tissue banking. The aim of this work was to characterize the quality of split thickness skin allografts cryopreserved or manufactured using highly concentrated solutions of glycerol (50, 85 or 98%), where tissue water activity (a_w), histology and birefringence changes were chosen as parameters. Consistent a_w outcomes validated the proposed processing protocols. While no significant changes in tissue quality were observed under bright-field microscopy or in collagen birefringence, in-process findings can be harnessed to fine-tune and optimize manufacturing outcomes in particular when further radiation sterilization is considered. Furthermore, exposing the tissues to 85% glycerol seems to derive the most efficient outcomes as far as a_w and control of microbiological growth.

Keywords: Birefringence; Glycerol; Processing; Skin allografts; Water activity.

MeSH terms

Adult
Collagen / metabolism*
Cryopreservation* / methods
Female
Glycerol / metabolism*
Humans
Male
Middle Aged
Skin Transplantation* / methods
Tissue Preservation / methods
Transplantation, Homologous / methods
Water*

Substances

Water
Collagen
Glycerol