Storage In Saline Solution Research Articles

Histological and Biomechanical Characteristics of Human Decellularized Allograft Heart Valves After Eighteen Months of Storage in Saline Solution.

Background: The best storage preservation method for maintaining the quality and safety of human decellularized allograft heart valves is yet to be established. Objective: The aim of the present study was to evaluate the stability in terms of extracellular matrix (ECM) integrity of human heart valve allografts decellularized using sodium dodecyl sulfate-ethylenediaminetetraacetic acid (SDS-EDTA) and stored for 6, 12, and 18 months. Methods: A total of 70 decellularized aortic and pulmonary valves were analyzed across different storage times (0, 6, 12, and 18 months) for solution pH measurements, histological findings, cytotoxicity assay results, biomechanical test results, and microbiological suitability test results. Continuous data were analyzed using one-way analysis of variance comparing the follow-up times. Results: The pH of the stock solution did not change during the different time points, and no microbial growth occurred up to 18 months. Histological analysis showed that the decellularized allografts did not present deleterious outcomes or signs of structural degeneration in the ECM up to 12 months. The biomechanical properties showed changes over time in different aspects. Allografts stored for 18 months presented lower tensile strength and elasticity than those stored for 12 months (p < 0.05). The microbiological suitability test suggested no residual antimicrobial effects. Conclusion: Changes in the structure and functionality of SDS-EDTA decellularized heart valve allografts occur after 12 months of storage.

Stable Nanocomposite Based on PEGylated and Silver Nanoparticles Loaded Graphene Oxide for Long-Term Antibacterial Activity

The increasing occurrence of antibiotic-resistant pathogens, especially superbugs, is compromising the efficacy of traditional antibiotics. Silver nanoparticles (AgNPs) loaded graphene oxide (GO) nanocomposite (GO-Ag) has drawn great interest as a promising alternative antibacterial material. However, GO-Ag nanocomposite often irreversibly aggregates in physiological solutions, severely influencing its antibacterial capacity and practical application. Herein, a PEGylated and AgNPs loaded GO nanocomposite (GO-PEG-Ag) is synthesized through a facile approach utilizing microwave irradiation, while avoiding extra reducing agents. Through PEGylation, the synthesized GO-PEG-Ag nanocomposite dispersed stably over one month in a series of media and resisted centrifugation at 10 000×g for 5 min, which would benefit effective contact between the nanocomposite and the bacteria. In contrast, GO-Ag aggregated within 1 h of dispersion in physiological solutions. In comparison with GO-Ag, GO-PEG-Ag showed stronger bactericidal capability toward not only normal Gram-negative/positive bacteria such as E. coli and S. aureus (∼100% of E. coli and ∼95.3% of S. aureus reduction by 10 μg/mL nanocomposite for 2.5 h), but also superbugs. Moreover, GO-PEG-Ag showed lower cytotoxicity toward HeLa cells. Importantly, GO-PEG-Ag presented long-term antibacterial effectiveness, remaining ∼95% antibacterial activity after one-week storage in saline solution versus <35% for GO-Ag. The antibacterial mechanisms of GO-PEG-Ag were evidenced as damage to the bacterial structure and production of reactive oxygen species, causing cytoplasm leakage and metabolism decrease. The stable GO-PEG-Ag nanocomposite with powerful and long-term antibacterial capability provides a more practical and effective strategy for fighting superbugs-including pathogen threats in biomedicine and public health.

Collection, storage and freezability of equine epididymal spermatozoa

The recovery of spermatozoa from the cauda epididymis may be the last chance to obtain genetic material from stallions undergone to castration. The aim of the current study was to evaluate the efficiency of cryopreservation and the use of two different extenders for equine epididymal spermatozoa. Testicles obtained from castration were divided into two groups: cauda epididymis processed immediately after orchiectomy and cauda epididymis processed after 24 h storage in saline solution at 4 °C of the testis. The epididymal spermatozoa were collected through manual slicing of the cauda epididymis of each testicle. In addition, spermatozoa obtained from different processed testes were diluted alternatively with either modified Palmer or EGG TECH® extenders to produce frozen straws. Motility parameters in fresh and frozen-thawed material were analysed by means of the computer-aided sperm analysis (CASA). The recorded CASA data were analysed with a mixed linear model. Motility parameters in fresh semen yielded better results than in frozen semen (p = 0.008), but no difference (p > 0.05) was observed between spermatozoa collected immediately after castration or after 24 h of storage; in frozen-thawed samples, EGG TECH® tended to improve the percentage of progressively motile spermatozoa in epididymal frozen-thawed semen (p = 0.08) compared with modified Palmer. We conclude that the processing of epididymal spermatozoa can occur up to 24 h after stallion castration and both common extenders used are suitable for preserving this material.

Sealability of Filled and Unfilled Fissure Sealants using Two Different drying agents

To evaluate and compare the effect of two different drying agents (PrimaDry and Ethyl alcohol 95% concentration.) on microleakage of filled (Ultraseal XT plus) and unfilled (Helioseal) fissure sealants in vivo and in vitro. A total of 60 extracted human upper and lower first premolars from15 adult healthy patients were divided into 2 groups 30 in vivo (Teeth were extracted 3 months after sealant application), and 30 in vitro (Teeth were stored 3 months in normal saline) each group were subdivided into 2 subgroups 15 sealed with filled (Ultraseal XT plus), while the other 15 were sealed with unfilled (Helioseal), each subgroup was subdivided into 3 classes composed of (5) premolars according to drying agent used: B0) without drying agent. B1) PrimaDry B2) Ethyl alcohol 95% concentration. After extraction teeth were thoroughly washed with water, cleaned with non-fluoridated (FL) prophylaxis paste. The unsealed were sealed after 3 months of storage in saline solution (in vitro).The occlusal surfaces were opened using tapered diamond fissure burs confined to enamel. Fissure sealant application was done following the manufacturer's instructions. The drying agent was applied after etching and before sealant application. Dye penetration method with methylene blue dye was used for microleakage assessment. The specimens were immersed in 1% methylene blue for 24h in order to allow dye penetration into possible gaps in the tooth–sealant interface. The teeth were sectioned longitudinally in using diamond saw, each section cleaned, examined and photographed under stereomicroscope at ×20 magnifications to assess dye penetration at the margins of the restorations. Two-way ANOVA was used for statistical analysis. In vivo results revealed that unfilled (Helioseal) achieved significant less microleakage than filled (Ultraseal XT plus) without any drying agent and PrimaDry with either filled or unfilled achieved the least microleakage. While in vitro results showed that both PrimaDry with Filled (Ultraseal XT plus) and Ethyl alcohol 95% concentration with Unfilled (Helioseal) achieved the least microleakage without significant statistical difference. Use of Ultraseal XT plus system according to manufacturer's directions showed the least microleakage both in vivo and in vitro. Use of PrimaDry increased the efficiency of both filled and unfilled fissure sealant.

Microleakage of the experimental composite resin with three component photoinitiator systems

This study was done to determine if there is any difference in microleakage between experimental composite resins, in which various proportions of three component photoinitiators (Camphoroquinone, OPPI, Amine) were included. Four kinds of experimental composite resin were made by mixing 3.2% silanated barium glass (78 wt.%, average size; 1 ) with each monomer system including variously proportioned photoinitiator systems used for photoinitiating BisGMA/BisEMA/TEGDMA monomer blend (37.5:37.5:25 wt.%). The weight percentage of each component were as follows (in sequence Camphoroquinone, OPPI, Amine): Group A - 0.5%, 0%, 1% / Group B - 2%, 0.2%, 2% / Group C - 0.2%, 1%, 0.2% / Group D - 1%, 1%, 2%. Each composite resin was used as a filling material for round class V cavities (diameter: 2/3 of mesiodistal width; depth: 1.5 mm) made on extracted human premolars and they were polymerized using curing light unit (XL 2500, 3M ESPE) for 40 s with an intensity of 600 mW/. Teeth were thermocycled fivehundred times between and for 30s at each temperature. Electrical conductivity () was recorded two times (just after thermocycling and after three-month storage in saline solution) by electrochemical method. Microleakage scores of each group according to evaluation time were as follows [Group: at first record / at second record; unit ()]: A: 3.80 (0.69) / 13.22 (4.48), B: 3.42 (1.33) / 18.84 (5.53), C: 4.18 (2.55) / 28.08 (7.75), D: 4.12 (1.86) / 7.41 (3.41). Just after thermocycling, there was no difference in microleakage between groups, however, group C showed the largest score after three-month storage. Although there seems to be no difference in microleakage between groups just after thermocycling, composite resin with highly concentrated initiation system or classical design (Camphoroquinone and Amine system) would be more desirable for minimizing microleakage after three-month storage.

The Effect of Different Adhesive Systems on the Retention Strength of Bonded Amalgam Restorations

The aim of this study was to evaluate the bond strength of bonded amalgam to dentin when unfilled and filled adhesive systems are employed using different application modes and to compare the adhesives with a cavity varnish and unlined restorations. One hundred and twenty sound third human molar teeth were used in the study. A cylindrical cavity 3.3 mm in diameter was prepared in a cross section of dentin approximately 3.0 mm in thickness. The specimens were divided into six experimental groups (n=20) according to the cavity liner used in the prepared cylindrical cavity: One Coat Bond (O), Scotchbond Multi-Purpose(S) , Panavia 21 (Pa), PQ1 (P), Copalite (C), and the unlined (U) group which served as the control group. Cavity surfaces were treated with the assigned adhesive/liner according to manufacturer's instructions then restored with amalgam. After storage in saline solution for seven days at 37 degrees C, the specimens were subjected to a push-out test at a crosshead speed of 1 mm/min. The mode of failure was assessed by microscopic analysis of the fracture sites. Data were analyzed by analysis of variance (ANOVA) and Duncan Multiple range tests (a=0.05). No significant difference in amalgam-dentin bond strength was found among O (23.47 MPa), S (21.02 MPa), and Pa (20.06 MPa) adhesive groups, but there was a significant difference between each of these groups and the P and C groups. The U group exhibited significantly lower retention than the other groups (P<0.05). Different bond strengths were observed with the different types of dentin bonding agents and liners employed. The lowest bond strength was seen in the U group. A statistically significant difference in bond strength was observed with O, S, and Pa compared to P, but this finding is not sufficient to rely on the bonding of amalgam to dentin, particularly in complex amalgam restorations.

Preservation of microelastic properties of dentin and tooth enamel in vitro—A scanning acoustic microscopy study

Objectives The aim of this study was to examine the influence of storage media on the elastic properties of dentin and tooth enamel with respect to the storage period. Several reports suggest that saline and other aqueous solutions may induce chemical reactions and the dissolution of minerals, which in turn may cause alterations of elastic tissue properties. Methods Three non-erupted human wisdom teeth were extracted and divided in three slices. Sections were stored in three different media for a maximum period of 21 days. During this time all sections were inspected by time-resolved 50-MHz scanning acoustic microscopy. Results Storage in saline solution resulted in a progressive decrease of the acoustic impedance up to 70% in dentin but not in enamel tissue. Hank's balanced salts solution and artificial saliva appeared to maintain the elastic properties of dentin and enamel during the entire time of storage. The measurements of surface wave velocities did not show significant differences. High resolution (900 MHz) inspection of sections cut perpendicular to the surface exposed to the storage media for 21 days revealed a progressive increase of impedance in dentin up to the initial values at a depth of approximately 300 μm. Significance These findings suggest that quantitative SAM is a suitable tool for assessing surface and sub-superficial elastic properties of tooth tissue.

The Changes in the Tensile Properties of Tendons after Freeze Storage in Saline Solution

The objective of this study is to evaluate the influence of saline solution (0.9 per cent NaCl) on the tensile properties of freeze-stored tendons. Firstly, 170 pieces of chicken flexor digitorum profundus tendons were retrieved and wrapped in saline-soaked gauze before they were stored at -40degreesC. Then specimens were tensile tested at various time points over 360 days, scanning electron microscopy (SEM) was performed on fresh specimens, and specimens were freeze-stored for 233 days to investigate microstructure change after freeze storage. The mean values of strain ultimate tensile strength (UTS) did not deviate significantly (analysis of variance; p = 0.249) following freeze storage while the UTS and elastic modulus increased gradually with the duration of freeze storage and the growth became significant (p < 0.01) for durations longer than 70 and 40 days respectively. The SEM study showed that the collagen fibre density of specimens stored for 233 days decreased because of porosity growth. These findings suggested that the saline increased the tensile strength and modulus of the collagen.

Assessment of endothelial preservation in human cell cultures

Impairment of microcirculation due to endothelial cell damage must be considered a limiting factor in organ preservation. The present study aims at a quantitative assessment of preservation-induced injury in cultured human endothelial cells. Monolayer cultures of human umbilical vein endothelial cells were exposed to cold (40 degrees C) hypoxic storage in University of Wisconsin solution, histidine-tryptophane-ketoglutarate solution, Euro-Collins solution, and saline solution. Cellular integrity was evaluated by viable cell count, ultrastructural analysis, and prostacyclin release after 24, 48, and 72 hours of storage and subsequent 6 hours of reincubation in culture medium at 37 degrees C. Expression of intercellular adhesion molecule-1 was investigated after 6, 12, and 24 hours of cold preservation and after 6 hours of rewarming. Cellular viability was best maintained with University of Wisconsin and histidine-tryptophane-ketoglutarate solutions with no significant reduction of cell count up to 72 hours; Euro-Collins solution and saline solution caused a significant decline in cell numbers after 24 hours (p < 0.05). Morphology was best preserved by University of Wisconsin solution. Prostacyclin values were elevated after 24 hours in Euro-Collins solution and saline solution, after 48 hours in histidine-tryptophane-ketoglutarate, Euro-Collins, and saline solutions, and after 72 hours in Euro-Collins solution (p < 0.05, compared with University of Wisconsin solution). ICAM expression was weak after cold storage (24 hours) in University of Wisconsin solution, moderate after incubation in histidine-tryptophane-ketoglutarate and Euro-Collins solutions and intensive after storage in saline solution. In contrast, rewarming caused intensive expression of intercellular adhesion molecule-1 in all experimental groups as compared with controls, which showed baseline expression at any time. From our results we conclude that in this model cellular integrity is best protected by University of Wisconsin solution, increased prostacyclin release is consistent with morphologic alterations and intercellular adhesion molecule-1 expression is clearly up-regulated in endothelial cells under reperfusion conditions after cold hypoxic storage.

Vitale Konservierung von Knorpeltransplantaten mittels Gewebekulturmethoden*

Cartilage grafting is one of the most common procedures in plastic surgery. Since storage of both autologous and allogenic cartilage is necessary, different preservation methods have been used with more or less success. The use of chemical preservation procedures like formaldehyde, Merthiolate or Cialit lead to a loss of the vitality of the graft. This work presents a study of the cell vitality and the matrix of cartilage grafts stored in different solutions (formaldehyde, saline, RPMI 1640, Ham F-12 and DMEM 4500) during 150 days. The cell viability was assessed using tissue sections (neutral red supravital staining and trypan blue dye exclusion test) and isolated cells (trypan blue dye exclusion test and cell adhesion in monolayer culture). The state of the cartilage matrix was analysed by means of the azan, alcian and toluidine blue staining). Cartilage immersed in formaldehyde solution lost 100% of the vitality after a storage period of 10 days, the one immersed in saline solution after 30 days. Cartilage stored in tissue culture media retained its vitality (> 85%) during the whole storage time. Histological staining methods showed a decrease of the staining intensity after 10 days storage in formaldehyde and after 30 days storage in saline solution. No differences in vitality and the matrix staining were found among all three culture media. Our results suggest that viable cartilage tissue can be successfully stored for a long time using tissue culture methods.

Influence of Perioperative Storage Solutions on Long-Term Vein Graft Function and Morphology

It has been shown that suboptimal preparation of a vein graft prior to its insertion results in immediate morphologic and functional damage to the endothelial cells but not to the underlying smooth muscle cells. However, little is known about whether such perioperative injury to the vein grafts influences the subsequent development of intimal hyperplasia and smooth muscle cell contractility. This study examines the influence of storage in saline solution or Ringer's lactate on the development of intimal hyperplasia and vasomotor function in experimental vein grafts. Twenty-six New Zealand white rabbits had a carotid vein bypass graft performed after the veins had been immersed (15 minutes) in either heparinized saline solution (Sal; n = 13) or Ringer's lactate (RL; n = 13), and each group was harvested after 28 days for either histologic (n = 8) or functional studies (n = 5; four 5 mm rings/graft). Saline storage of the vein graft resulted in a 38% increase in the thickness of the intimal hyperplasia (113 +/- 2 vs. 83 +/- 2 microns, Sal vs. RL; mean +/- SEM; p < 0.05) without a change in medial thickness (87 +/- 5 vs. 86 +/- 8 microns, Sal vs. RL; p > 0.05). The two sets of vein grafts showed no difference in sensitivity to norepinephrine, serotonin, and bradykinin.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in Fish Proteins Caused by Storage in Saline Solution and Their Inhibition by Phosphates.

SUMMARY— It is known that even small concentrations of sodium chloride cause a loss in the solubility of actomyosin in fillets of Baltic herring. This change is prevented by the simultaneous presence of a sufficient amount of phosphates. To date, the mode of action of phosphates is unsettled. This problem has here been studied by the aid of radioactive pyrophosphate.The fillets were kept in solutions containing sodium chloride, pyrophosphate, or both, at +4°C. The migration of tracer pyrophosphate was followed by application of the auto‐radiographic method; at the same time, changes in the solubility of actomyosin were checked. To avoid losses of soluble compounds, the sections for autoradiogaphy were prepared by freeze‐drying and paraffin impregnation techniques. It was found that the migration was very rapid: in 24 hr the fillets were completely marked. The rate of migration was also estimated by counting of the sections.Studies were also made of the changes in the phosphorus fractions of the fillets during the course of standing using 1% pyrophosphate and maximal standing time of 5 days. Initially, there occurred a rapid loss of phosphorus compounds from the fillets; this related to the lipid and nucleic acid phosphorus. The tracer migrated rapidly into the fillets during the first day, and more slowly after this. The bulk of the tracer was in the acid‐soluble fraction. Apparently, there also occurred some incorporation into the lipids and nucleic acids.

VEIN GRAFTS: Changes in Phospholipid Structure due to Storage in Saline Solution

VEIN GRAFTS: Changes in Phospholipid Structure due to Storage in Saline Solution