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Current Opinion in Organ Transplantation Oct 2022Older donors have the potential to close the gap between demand and supply in solid organs transplantation. Utilizing older organs, at the same time, has been associated... (Review)
Review
PURPOSE OF REVIEW
Older donors have the potential to close the gap between demand and supply in solid organs transplantation. Utilizing older organs, at the same time, has been associated with worse short- and long-term outcomes. Here, we introduce potential mechanisms on how treatments during machine perfusion (MP) may safely improve the utilization of older organs.
RECENT FINDINGS
Consequences of ischemia reperfusion injury (IRI), a process of acute, sterile inflammation leading to organ injury are more prominent in older organs. Of relevance, organ age and IRI seem to act synergistically, leading to an increase of damage associated molecular patterns that trigger innate and adaptive immune responses. While cold storage has traditionally been considered the standard of care in organ preservation, accumulating data support that both hypothermic and normothermic MP improve organ quality, particularly in older organs. Furthermore, MP provides the opportunity to assess the quality of organs while adding therapeutic agents. Experimental data have already demonstrated the potential of applying treatments during MP. New experimental show that the depletion of senescent cells that accumulate in old organs improves organ quality and transplant outcomes.
SUMMARY
As the importance of expanding the donor pool is increasing, MP and novel treatments bear the potential to assess and regenerate older organs, narrowing the gap between demand and supply.
Topics: Aged; Humans; Organ Preservation; Organ Transplantation; Perfusion; Senotherapeutics; Tissue Donors
PubMed: 35950886
DOI: 10.1097/MOT.0000000000001019 -
Frontiers in Immunology 2022The liver has been proposed as an important "immune organ" of the body, as it is critically involved in a variety of specific and unique immune tasks. It contains a huge... (Review)
Review
The liver has been proposed as an important "immune organ" of the body, as it is critically involved in a variety of specific and unique immune tasks. It contains a huge resident immune cell repertoire, which determines the balance between tolerance and inflammation in the hepatic microenvironment. Liver-resident immune cells, populating the sinusoids and the space of Disse, include professional antigen-presenting cells, myeloid cells, as well as innate and adaptive lymphoid cell populations. Machine perfusion (MP) has emerged as an innovative technology to preserve organs while testing for organ quality and function prior to transplantation. As for the liver, hypothermic and normothermic MP techniques have successfully been implemented in clinically routine, especially for the use of marginal donor livers. Although there is evidence that ischemia reperfusion injury-associated inflammation is reduced in machine-perfused livers, little is known whether MP impacts the quantity, activation state and function of the hepatic immune-cell repertoire, and how this affects the inflammatory milieu during MP. At this point, it remains even speculative if liver-resident immune cells primarily exert a pro-inflammatory and hence destructive effect on machine-perfused organs, or in part may be essential to induce liver regeneration and counteract liver damage. This review discusses the role of hepatic immune cell subtypes during inflammatory conditions and ischemia reperfusion injury in the context of liver transplantation. We further highlight the possible impact of MP on the modification of the immune cell repertoire and its potential for future applications and immune modulation of the liver.
Topics: Humans; Organ Preservation; Perfusion; Liver; Reperfusion Injury; Inflammation
PubMed: 36311746
DOI: 10.3389/fimmu.2022.982018 -
Scientific Reports Jul 2021Even though dried sperm is not viable, it can be used for fertilization as long as its chromatin remains intact. In this study, we investigated drying- and...
Even though dried sperm is not viable, it can be used for fertilization as long as its chromatin remains intact. In this study, we investigated drying- and temperature-induced conformational changes of nucleic acids and stallion sperm chromatin. Sperm was diluted in preservation formulations with and without sugar/albumin and subjected to convective drying at elevated temperatures on glass substrates. Accumulation of reactive oxygen species was studied during storage at different temperatures, and the sperm chromatin structure assay was used to assess DNA damage. Fourier transform infrared spectroscopy was used to identify dehydration and storage induced conformational changes in isolated DNA and sperm chromatin. Furthermore, hydrogen bonding in the preservation solutions associated with storage stability were investigated. Reactive oxygen species and DNA damage in dried sperm samples were found to accumulate with increasing storage temperature and storage duration. Non-reducing disaccharides (i.e., trehalose, sucrose) and albumin counteracted oxidative stress and preserved sperm chromatin during dried storage, whereas glucose increased DNA damage during storage. When sperm was dried in the presence of trehalose and albumin, no spectral changes were detected during storage at refrigeration temperatures, whereas under accelerated aging conditions, i.e., storage at 37 °C, spectral changes were detected indicating alterations in sperm chromatin structure.
Topics: Animals; Chromatin; DNA Damage; Freeze Drying; Male; Nucleic Acid Conformation; Nucleic Acids; Reactive Oxygen Species; Semen Preservation; Spectroscopy, Fourier Transform Infrared; Spermatozoa; Temperature
PubMed: 34234244
DOI: 10.1038/s41598-021-93569-y -
Poultry Science Oct 2021The present study focuses on the effect of different levels of ergothioneine and thawing temperature on rooster semen cryopreservation. Semen was diluted in Lake...
The present study focuses on the effect of different levels of ergothioneine and thawing temperature on rooster semen cryopreservation. Semen was diluted in Lake extender containing ergothioneine at 5, 10, 15, and 20 µM and cryopreserved. Two thawing temperatures (37°C for 30 s and 60°C for 5 s) were consequently examined. Sperm motility parameter, membrane integrity, abnormal morphology, viability, apoptotic status, mitochondria activity, and lipid peroxidation were determined after freeze-thaw process. Ergothioneine levels of 5 and 10 µM led to higher (P < 0.05) total motility (66.58 ± 1.44 and 72.11±1.44, respectively) and average path velocity (VAP) (34.54 ± 0.89, 37.28 ± 0.89, respectively). Higher (P < 0.05) significant membrane integrity and mitochondria activity after freeze-thawing were observed in the groups supplemented with 10 µM ergothioneine (68.62 ± 1.24 and 69.12 ± 1.26, respectively). Also, 5 and 10 µM of ergothioneine led to the lowest significant percentage of apoptotic and dead sperm. The total motility and progressive motility resulted in significantly (P < 0.05) higher amount when sperm were thawed with 60°C (60.58 ± 0.91 and 24.76 ± 0.53, respectively) compared to thawed sperm in 37°C. The membrane integrity, viability and mitochondria activity led to significantly (P < 0.05) higher when sperm were thawed with 60°C (58.2 ± 0.78, 63.21 ± 0.80 and 56.85 ± 0.79, respectively). It could be concluded the addition of 5 and 10 µM ergothioneine in the semen extender and thawing temperature at 60˚C in 5 s can be an efficient strategy to preserve rooster cryopreserved semen quality.
Topics: Animals; Chickens; Cryopreservation; Cryoprotective Agents; Ergothioneine; Male; Semen; Semen Analysis; Semen Preservation; Sperm Motility; Spermatozoa; Temperature
PubMed: 34464932
DOI: 10.1016/j.psj.2021.101405 -
Food Research International (Ottawa,... May 2020The objective of this work was to produce solid lipid microparticles using fully hydrogenated anhydrous milk fat (FHAMF) and to evaluate their physical stability during...
The objective of this work was to produce solid lipid microparticles using fully hydrogenated anhydrous milk fat (FHAMF) and to evaluate their physical stability during 90 days of storage at different temperatures. To obtain the lipid microparticles, the FHAMF was sprayed in a double fluid atomizer at 1 bar pressure, in a chilled chamber (2 °C). After atomization, the microparticles were divided into three batches and stored for 90 days at three different temperatures (5, 15 and 25 °C). During storage, samples were periodically removed (7, 15, 30, 60 and 90 days) for evaluation of particle size, melting behavior, morphology, and polymorphic habit. The microparticles presented spherical shaped, with a smooth surface and wide size variation. When stored at 5 °C, the microparticles showed the smaller size and smaller agglomeration, due to the lower liquid fat content in the system, which that makes it difficult the adhesion of one particle to another. The lipid microparticles presented β' crystals immediately after processing and at all temperatures during the storage. This study demonstrated the potential of FHAMF as an appropriate lipid phase for the production of lipid microparticles, and may contribute to further studies on the delivery of active compounds.
Topics: Animals; Dairy Products; Hydrogenation; Lipids; Milk; Nanoparticles; Particle Size; Preservation, Biological; Spray Drying; Temperature
PubMed: 32247456
DOI: 10.1016/j.foodres.2020.109009 -
Journal of Veterinary Science Nov 2023The need for a storage method capable of preserving the intrinsic properties of bones without using toxic substances has always been raised. Supercooling is a relatively...
BACKGROUND
The need for a storage method capable of preserving the intrinsic properties of bones without using toxic substances has always been raised. Supercooling is a relatively recently introduced preservation method that meets this need. Supercooling refers to the phenomenon of liquid in which the temperature drops below its freezing point without solidifying or crystallizing.
OBJECTIVES
The purpose of this study was to identify the preservation efficiency and applicability of the supercooling technique as a cortical bone allograft storage modality.
METHODS
The biomechanical effects of various storage methods, including deep freezing, cryopreservation, lyophilization, glycerol preservation, and supercooling, were evaluated with the three-point banding test, axial compression test, and electron microscopy. Additionally, cortical bone allografts were applied to the radial bone defect in New Zealand White rabbits to determine the biological effects. The degree of bone union was assessed with postoperative clinical signs, radiography, micro-computed tomography, and biomechanical analysis.
RESULTS
The biomechanical properties of cortical bone grafts preserved using glycerol and supercooling method were found to be comparable to those of normal bone while also significantly stronger than deep-frozen, cryopreserved, and lyophilized bone grafts. Preclinical research performed in rabbit radial defect models revealed that supercooled and glycerol-preserved bone allografts exhibited significantly better bone union than other groups.
CONCLUSIONS
Considering the biomechanical and biological superiority, the supercooling technique could be one of the optimal preservation methods for cortical bone allografts. This study will form the basis for a novel application of supercooling as a bone material preservation technique.
Topics: Animals; Rabbits; X-Ray Microtomography; Glycerol; Transplantation, Homologous; Cryopreservation; Cortical Bone; Allografts
PubMed: 37904641
DOI: 10.4142/jvs.23183 -
Cryobiology Dec 2021We evaluated the effect of open and closed systems used for ovarian tissue vitrification on the microbiological load and preservation of preantral follicles (PAFs) in...
We evaluated the effect of open and closed systems used for ovarian tissue vitrification on the microbiological load and preservation of preantral follicles (PAFs) in the red-rumped agoutis. The ovaries from eight females were recovered and fragmented, with four cortexes fragments immediately fixed and evaluated (fresh group). The other fragments were processed for the solid-surface vitrification method (SSV) or an ovarian tissue cryosystem (OTC) using fetal calf serum, ethylene glycol, and sucrose as cryoprotectants, stored for two weeks, and rewarmed. Subsequently, fragments were subjected to a 24-h in vitro culture and assessed for microbiological load, PAF morphology, and DNA integrity. There was no fungal contamination; however, the vitrified samples from two individuals showed bacterial contamination of 79 200 colony forming units per milliliter (CFU)/mL for SSV and 3120 CFU/mL for OTC. From those samples, a total of eight different types of bacterial colonies were isolated and identified as coagulase-negative Staphylococci and Gram-positive bacilli. Regarding PAF morphology, both systems provided adequate preservation, with values higher than 70% normal follicles observed before and after culture. The TUNEL assay revealed that both SSV (52.39%) and OTC (41.67%) could preserve DNA integrity after vitrification and after 24 h of culture. In summary, both open and closed systems were equally efficient in preserving agouti ovarian tissues, especially concerning the preantral follicle morphology and DNA integrity; however, the OTC seems to provide a less adequate environment for bacterial proliferation.
Topics: Animals; Cryopreservation; Cryoprotective Agents; Dasyproctidae; Female; Humans; Ovarian Follicle; Tissue Preservation; Vitrification
PubMed: 34454959
DOI: 10.1016/j.cryobiol.2021.08.003 -
Nature Communications May 2024The growing disparity between the demand for transplants and the available donor supply, coupled with an aging donor population and increasing prevalence of chronic...
The growing disparity between the demand for transplants and the available donor supply, coupled with an aging donor population and increasing prevalence of chronic diseases, highlights the urgent need for the development of platforms enabling reconditioning, repair, and regeneration of deceased donor organs. This necessitates the ability to preserve metabolically active kidneys ex vivo for days. However, current kidney normothermic machine perfusion (NMP) approaches allow metabolic preservation only for hours. Here we show that human kidneys discarded for transplantation can be preserved in a metabolically active state up to 4 days when perfused with a cell-free perfusate supplemented with TCA cycle intermediates at subnormothermia (25 °C). Using spatially resolved isotope tracing we demonstrate preserved metabolic fluxes in the kidney microenvironment up to Day 4 of perfusion. Beyond Day 4, significant changes were observed in renal cell populations through spatial lipidomics, and increases in injury markers such as LDH, NGAL and oxidized lipids. Finally, we demonstrate that perfused kidneys maintain functional parameters up to Day 4. Collectively, these findings provide evidence that this approach enables metabolic and functional preservation of human kidneys over multiple days, establishing a solid foundation for future clinical investigations.
Topics: Humans; Kidney; Organ Preservation; Perfusion; Kidney Transplantation; Male; Organ Preservation Solutions; Female; Middle Aged; Cell-Free System; Citric Acid Cycle; Adult; Nutrients; Lipidomics; Aged
PubMed: 38740760
DOI: 10.1038/s41467-024-47106-w -
Microbiome May 2022Novel strategies for anaerobic bacterial isolations from human faecal samples and various initiatives to generate culture collections of gut-derived bacteria have...
BACKGROUND
Novel strategies for anaerobic bacterial isolations from human faecal samples and various initiatives to generate culture collections of gut-derived bacteria have instigated considerable interest for the development of novel microbiota-based treatments. Early in the process of building a culture collection, optimal faecal sample preservation is essential to safeguard the viability of the broadest taxonomic diversity range possible. In contrast to the much more established faecal storage conditions for meta-omics applications, the impact of stool sample preservation conditions on bacterial growth recovery and isolation remains largely unexplored. In this study, aliquoted faecal samples from eleven healthy human volunteers selected based on a range of physicochemical and microbiological gradients were cryopreserved at - 80 °C either without the addition of any medium (dry condition) or in different Cary-Blair medium conditions with or without a cryoprotectant, i.e. 20% (v/v) glycerol or 5% (v/v) DMSO. Faecal aliquots were subjected to bulk 16S rRNA gene sequencing as well as dilution plating on modified Gifu Anaerobic Medium after preservation for culturable fraction profiling and generation of bacterial culture collections.
RESULTS
Analyses of compositional variation showed that cryopreservation medium conditions affected quantitative recovery but not the overall community composition of cultured fractions. Post-preservation sample dilution and richness of the uncultured source samples were the major drivers of the cultured fraction richness at genus level. However, preservation conditions differentially affected recovery of specific genera. Presence-absence analysis indicated that twenty-two of the 45 most abundant common genera (>0.01% abundance, dilution 10) were recovered in cultured fractions from all preservation conditions, while nine genera were only detected in fractions from a single preservation condition. Overall, the highest number of common genera (i.e. 35/45) in cultured fractions were recovered from sample aliquots preserved without medium and in the presence of Cary-Blair medium containing 5% (v/v) DMSO. Also, in the culture collection generated from the cultured fractions, these two preservation conditions yielded the highest species richness (72 and 66, respectively).
CONCLUSION
Our results demonstrate that preservation methods partly determine richness and taxonomic diversity of gut anaerobes recovered from faecal samples. Complementing the current standard practice of cryopreserving stool samples in dry conditions with other preservation conditions, such as Cary-Blair medium with DMSO, could increase the species diversity of gut-associated culture collections. Video abstract.
Topics: Cryopreservation; Culture Media; Dimethyl Sulfoxide; Feces; Humans; RNA, Ribosomal, 16S
PubMed: 35644616
DOI: 10.1186/s40168-022-01267-2 -
American Journal of Transplantation :... Apr 2020
Topics: Organ Preservation; Perfusion; Technology
PubMed: 32222099
DOI: 10.1111/ajt.15839