Premium
The feasibility of gamma radiation sterilization for decellularized tracheal grafts
Author(s) -
Johnson Christopher M.,
Guo DeHuang,
Ryals Stephanie,
Postma Gregory N.,
Weinberger Paul M.
Publication year - 2017
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1002/lary.26367
Subject(s) - decellularization , bioburden , biomedical engineering , cartilage , extracellular matrix , sterilization (economics) , ultrastructure , chemistry , tissue engineering , surgery , anatomy , medicine , biochemistry , monetary economics , economics , foreign exchange market , foreign exchange
Objectives/Hypothesis The most promising stem cell‐derived tracheal transplantation approach is dependent upon the use of decellularized tracheal grafts. It has been assumed that a sterilization step, such as gamma radiation, would damage the delicate extracellular matrix of the graft, thus rendering it less viable for cellular repopulation, although this has not been thoroughly investigated. Study Design Laboratory‐based comparative analysis. Methods Fifteen murine tracheas of strain C57/B‐6 mice were obtained. Thirteen were subjected to a detergent‐enzymatic decellularization process. Of these decellularized tracheas (DT), eight were irradiated, exposing five tracheas to a radiation level of 25 kGy (DT25) and three to 5 kGy (DT5). Two were left untreated. The two untreated tracheas, two DTs, and two DT25s were prepared and examined using both scanning and transmission electron microscopy. Bioburden calculations were obtained from three DTs, three DT25s, and three DT5s by homogenization, serial dilution, and streak plating. Results Electron microscopy of untreated fresh tracheas and DTs showed a slight qualitative degradation of cartilage ultrastructure due to the decellularization process. In contrast, examination of DT25 shows significant degradation including poor overall preservation of cartilage architecture with disorganized collagen fibers. The nonirradiated DTs had a calculated bacterial bioburden of 7.8 × 10 7 to 3.4 × 10 8 colony‐forming units per gram. Both the DT25 and DT5 specimens were found to have a bioburden of zero. Conclusions Gamma radiation at 25 kGy degrades the architecture of decellularized tracheal grafts. These ultrastructural changes may prove detrimental to graft viability; however, bioburden calculations suggest that a 5 kGy radiation dose may be sufficient for sterilization. Level of Evidence NA Laryngoscope , 127:E258–E264, 2017