OBJECTIVE: To test the use of rainbow trout skin as a surgical mesh in abdominal hernioplasties in rats.
METHODS: The experiment involved 20 Wistar rats receiving implants of trout skin processed for disinfection in 0.5% glutaraldehyde and preserved in 100% glycerin. The animals were divided into four groups, divided at 7, 15, 30, and 90 days postoperatively. Clinical and infrared thermography evaluations were performed, and after euthanasia, assessments of adhesion formations and sample collection for histological evaluation were conducted.
RESULTS: The implant was observed to be intact, ensuring the integrity of the abdominal wall, support for the viscera, and normal mobility for the rats for up to 90 days. Low rates of clinical alterations were observed, with an intense inflammatory reaction up to day 7, chronic inflammation and the onset of angiogenesis at day 15, and a low inflammatory reaction with collagenous infiltrate and fibrosis at day 30. At day 90, the implants showed a collagenous and fibrotic infiltrate with a minimal inflammatory infiltrate.
CONCLUSIONS: The surgical mesh of trout skin performed well, making it a potential alternative for surgical procedures in muscle aponeurotic corrections in the abdominal wall.

BACKGROUND: The current study presents a novel and precise surgical technique for complete reconstruction of the aortic valve using glutaraldehyde-treated autologous pericardium in a patient with aortic valve disease and endocarditis. The technique aims to provide a more effective and reproducible method for aortic valve repair, with the goal of improving outcomes and quality of life for patients with aortic valve disease.
METHODS: A 35-year-old Iranian male with aortic valve disease and endocarditis underwent aortic valve reconstruction surgery. Preoperative echocardiography showed a degenerative aortic valve with severe regurgitation, reduced left ventricular ejection fraction, and specific aortic root dimensions. The surgical technique involved precise measurements and calculations to design the size and shape of the new aortic valve cusps using autologous pericardium, with the goal of optimizing coaptation and function. The surgeon calculated the intercommissural distance based on the aortic annulus diameter to determine cusp size and shape. He tailored the pericardial cusps to have a height equal to 80% of the coaptation margin length. Detailed suturing techniques were used to ensure proper alignment and coaptation of the new cusps. Intraoperative evaluation of the valve function using suction and transesophageal echocardiography showed good coaptation and minimal residual regurgitation. At the 3-year follow-up, the patient had a well-functioning aortic valve with only trivial leak and was in satisfactory clinical condition.
CONCLUSIONS: Glutaraldehyde-treated autologous pericardium is a validated leaflet alternative, and the causes of its failure are late annular dilatation and other technique breakdowns. Current evidence reveals that aortic valve reconstruction with glutaraldehyde-treated autologous pericardium is associated with many advantages with the potential to improve patient outcomes and quality of life. Further clinical studies are warranted to evaluate the long-term durability and efficacy of this approach.

We present the synthesis of a cross-linking enzyme aggregate (CLEAS) of a peroxidase from Megathyrsus maximus (Guinea Grass) (GGP). The biocatalyst was produced using 50%v/v ethanol and 0.88%w/v glutaraldehyde for 1 h under stirring. The immobilization yield was 93.74% and the specific activity was 36.75 U mg-1. The biocatalyst surpassed by 61% the free enzyme activity at the optimal pH value (pH 6 for both preparations), becoming this increase in activity almost 10-fold at pH 9. GGP-CLEAS exhibited a higher thermal stability (2-4 folds) and was more stable towards hydrogen peroxide than the free enzyme (2-3 folds). GGP-CLEAS removes over 80% of 0.05 mM indigo carmine at pH 5, in the presence of 0.55 mM H2O2 after 60 min of reaction, a much higher value than when using the free enzyme. The operational stability showed a decrease of enzyme activity (over 60% in 4 cycles), very likely related to suicide inhibition.

BACKGROUND: Vinyl polyether silicone (VPES) is a novel impression biomaterial made of a combination of vinyl polysiloxane (VPS) and polyether (PE). Thus, it is significant to assess its properties and behaviour under varied disinfectant test conditions. This study aimed to assess the dimensional stability of novel VPES impression material after immersion in standard disinfectants for different time intervals.
METHODS: Elastomeric impression material used -medium body regular set (Monophase) [Exa\'lence GC America]. A total of 84 Specimens were fabricated using stainless steel die and ring (ADA specification 19). These samples were distributed into a control group (n=12) and a test group (n=72). The test group was divided into 3 groups, based on the type of disinfectant used - Group-A- 2% Glutaraldehyde, Group-B- 0. 5% Sodium hypochlorite and Group-C- 2% Chlorhexidine each test group was further divided into 2 subgroups (n=12/subgroup) based on time intervals for which each sample was immersed in the disinfectants - subgroup-1- 10 mins and Subgroup 2- 30 mins. After the impression material was set, it was removed from the ring and then it was washed in water for 15 seconds. Control group measurements were made immediately on a stereomicroscope and other samples were immersed in the three disinfection solutions for 10 mins and 30 mins to check the dimensional stability by measuring the distance between the lines generated by the stainless steel die on the samples using a stereomicroscope at x40 magnification.
RESULTS: The distance measured in the control group was 4397.2078 µm and 4396.1571 µm; for the test group Group-A- 2% Glutaraldehyde was 4396.4075 µm and 4394.5992 µm; Group-B- 0. 5% Sodium hypochlorite was 4394.5453 µm and 4389.4711 µm Group-C- 2% Chlorhexidine was 4395.2953 µm and 4387.1703 µm respectively for 10 mins and 30 mins. Percentage dimensional change was in the range of 0.02 - 0.25 for all the groups for 10 mins and 30 mins.
CONCLUSIONS: 2 % Glutaraldehyde is the most suitable disinfectant for VPES elastomeric impression material in terms of dimensional stability and shows minimum dimensional changes as compared to that of 2% Chlorhexidine and 0.5% Sodium hypochlorite.

The freeze-drying is a technology that preserves biological samples in a dry state, which is beneficial for storage, transportation, and cost saving. In this study, the bovine pericardium was treated with a freeze-drying protectant composed of polyethylene glycol (PEG) and trehalose (Tre), and then freeze-dried. The results demonstrated that the mechanical properties of the pericardium treated with PEG + 10% w/v Tre were superior to those of the pericardium fixed with glutaraldehyde (GA). The wet state water content of the rehydrated pericardium, determined using the Karl Fischer method, was (74.81 ± 1.44)%, which was comparable to that of the GA-fixed pericardium. The dry state water content was significantly reduced to (8.64 ± 1.52)%, indicating effective dehydration during the freeze-drying process. Differential scanning calorimetry (DSC) testing revealed that the thermal shrinkage temperature of the pericardium was (84.96 ± 0.49) ℃, higher than that of the GA-fixed pericardium (83.14 ± 0.11) ℃, indicating greater thermal stability. Fourier transform infrared spectroscopy (FTIR) results showed no damage to the protein structure during freeze-drying. Hematoxylin and eosin (HE) staining demonstrated that the freeze-drying process reduced pore formation, prevented ice crystal growth, and resulted in a tighter arrangement of tissue fibers. The frozen-dried bovine pericardium was subjected to tests for cell viability and hemolysis rate. The results revealed a cell proliferation rate of (77.87 ± 0.49)%, corresponding to a toxicity grade of 1. Additionally, the hemolysis rate was (0.17 ± 0.02)%, which is below the standard of 5%. These findings indicated that the frozen-dried bovine pericardium exhibited satisfactory performance in terms of cytotoxicity and hemolysis, thus meeting the relevant standards. In summary, the performance of the bovine pericardium treated with PEG + 10% w/v Tre and subjected to freeze-drying could meet the required standards.
冷冻干燥是一种使生物样本在干燥状态下保存的技术，有利于储存、运输并节省成本。本文使用聚乙二醇（PEG）和海藻糖（Tre）组成的冻干保护剂处理牛心包，进行冷冻干燥。结果表明：使用PEG + 10% w/v Tre处理牛心包进行冷冻干燥后，其力学性能优于使用戊二醛（GA）固定的牛心包。卡尔费休法测定，牛心包复水后的湿态含水量为（74.81 ± 1.44）%，与GA固定的牛心包无明显差异。干态含水量为（8.64 ± 1.52）%，说明在冷冻干燥过程中能有效脱水。差示扫描量热仪（DSC）的测试结果显示，牛心包的热皱缩温度为（84.96 ± 0.49）℃比GA固定的牛心包（83.14 ± 0.11）℃高，说明具有更高的热稳定性。傅里叶变换红外光谱（FTIR）结果显示，在冷冻干燥过程中，蛋白质结构并未受到破坏。苏木精-伊红（HE）染色表明，冷冻干燥过程可以减少孔隙的产生，防止冰晶的生长，使组织纤维结构排列更紧密。细胞存活率与溶血率检测结果显示，细胞增殖率为（77.87 ± 0.49）%，毒性分级为1级，溶血率为（0.17 ± 0.02）%，低于5%的标准，即经过冷冻干燥处理的牛心包在细胞毒性和溶血方面表现良好，符合相关标准。综上，使用PEG + 10% w/v Tre处理牛心包进行冷冻干燥后的性能符合要求。.

OBJECTIVE: Aortic valve neocuspidization (AVNeo) using autologous pericardium is a promising technique. Expected advantages are reduced immune response, appropriate biomechanics and lower treatment expenses. Nevertheless, autologous pericardium can be affected by patient\'s age and comorbidities. Usually, glutaraldehyde (GA) - fixed bovine pericardium is the basic material for aortic valve prostheses, easy available and carefully pre-examined in a standardized fabrication process. Aim of the study is the verification of autologous pericardial tissue homogeneity by analysing tissue thickness, biomechanics and extracellular matrix (ECM) composition.
METHODS: Segments of human GA-fixed pericardium selected by the surgeon based on visual criteria for cusp pre-cut and remaining after surgical AV replacement were investigated in comparison to bovine standard tissue treated equivalently. Pericardium sampling was performed at up to three positions of each sutured cusp for histological or biomechanical analysis, according to tissue availability.
CONCLUSIONS: Human pericardia exhibited a higher heterogeneity in collagen content, density of vessel structures and elastic moduli. Thickness, vessel density and collagen and elastin content differed significantly between the species. In contrast, significant interindividual differences were detected in most properties investigated for human pericardial samples but only for tissue thickness in bovine tissues. Higher heterogeneity of human pericardium, differing vessel and collagen content compared to bovine state-of-the-art material might be detrimental for long term AV functionality or deterioration and have to be intensely investigated in patients follow up after autologous cusp replacement.

BACKGROUND: Various methods, chemical and physical, disinfect dental impressions. Common chemicals include 1% Sodium Hypochlorite and 2% glutaraldehyde, while UV radiation is a prevalent physical method. Few studies compare their effects on dimensional stability in polyether impressions. This study aims to assess such stability using different disinfection methods. Therefore, this study was planned to evaluate the dimensional stability of polyether impression material using different disinfection methods.
METHODS: This in vitro study compared the effects of chemical disinfectants (1% Sodium Hypochlorite and 2% glutaraldehyde) and UV irradiation on the dimensional stability of polyether impression material. Groups A, B, C, and D, each with ten samples (N = 10), were studied. Group A was untreated (control). Group B was treated with 2% glutaraldehyde for 20 min, Group C with 1% Sodium Hypochlorite for 20 min, and Group D with UV rays for 20 min. A pilot milling machine drill was used to make four parallel holes labeled A, B, C, and D in the anterior and premolar regions from right to left. After sequential drilling, four implant analogs were positioned using a surveyor for accuracy. Ten open-tray polyether impressions were made and treated as described in the groups, followed by pouring the corresponding casts. Distortion values for each disinfection method were measured using a coordinate measuring machine capable of recording on the X- and Y-axes.
RESULTS: A comprehensive analysis was conducted using the one-way ANOVA test for distinct groups labeled A, B, C, and D, revealing significant differences in the mean distances for X1, X2, X4, X5, and X6 among the groups, with p-values ranging from 0.001 to 0.000. However, no significant differences were observed in X3. Notably, mean distances for the Y variables exhibited substantial differences among the groups, emphasizing parameter variations, with p-values ranging from 0.000 to 0.033. The results compared the four groups using the one-way ANOVA test, revealing statistically significant distance differences for most X and Y variables, except for X3 and Y4. Similarly, post-hoc Tukey\'s tests provided specific pairwise comparisons, underlining the distinctions between group C and the others in the mean and deviation distances for various variables on both the X- and Y-axes.
CONCLUSIONS: This study found that disinfection with 1% sodium hypochlorite or UV rays for 20 min maintained dimensional stability in polyether impressions.

Cyanophycin (CGP) is a polypeptide consisting of amino acids-aspartic acid in the backbone and arginine in the side chain. Owing to its resemblance to cell adhesive motifs in the body, it can be considered suitable for use in biomedical applications as a novel component to facilitate cell attachment and tissue regeneration. Although it has vast potential applications, starting with nutrition, through drug delivery and tissue engineering to the production of value-added chemicals and biomaterials, CGP has not been brought to the industry yet. To develop scaffolds using CGP powder produced by bacteria, its properties (e.g., biocompatibility, morphology, biodegradability, and mechanical strength) should be tailored in terms of the requirements of the targeted tissue. Crosslinking commonly stands for a primary modification method for renovating biomaterial features to these extents. Herein, we aimed to crosslink CGP for the first time and present a comparative study of different methods of CGP crosslinking including chemical, physical, and enzymatic methods by utilizing glutaraldehyde (GTA), UV exposure, genipin, 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS), and monoamine oxidase (MAO). Crosslinking efficacy varied among the samples crosslinked via the different crosslinking methods. All crosslinked CGP were non-cytotoxic to L929 cells, except for the groups with higher GTA concentrations. We conclude that CGP is a promising candidate for scaffolding purposes to be used as part of a composite with other biomaterials to maintain the integrity of scaffolds. The initiative study demonstrated the unknown characteristics of crosslinked CGP, even though its feasibility for biomedical applications should be confirmed by further examinations. KEY POINTS: • Cyanophycin was crosslinked by 5 different methods • Crosslinked cyanophycin is non-cytotoxic to L929 cells • Crosslinked cyanophycin is a promising new material for scaffolding purposes.

Conventional techniques for the closure of wounds, such as sutures and staples, have significant drawbacks that can negatively impact wound healing. Tissue adhesives have emerged as promising alternatives, but poor adhesion, low mechanical properties, and toxicity have hindered their widespread clinical adoption. In this work, a dual modified, aldehyde and methacrylate hyaluronic acid (HA) biopolymer (HA-MA-CHO) has been synthesized through a simplified route for use as a double cross-linked network (DCN) hydrogel (HA-MA-CHO-DCN) adhesive for the effective closure and sealing of wounds. HA-MA-CHO-DCN cross-links in two stages: initial cross-linking of the aldehyde functionality (CHO) of HA-MA-CHO using a disulfide-containing cross-linker, 3,3\'-dithiobis (propionic hydrazide) (DTPH), leading to the formation of a self-healing injectable gel, followed by further cross-linking via ultraviolet (UV) initiated polymerization of the methacrylate (MA) functionality. This hydrogel adhesive shows a stable swelling behavior and remarkable versatility as the storage modulus (G\') has shown to be highly tunable (103-105 Pa) for application to many different wound environments. The new HA-MA-CHO-DCN hydrogel showed excellent adhesive properties by surpassing the burst pressure and lap-shear strength for the widely used bovine serum albumin-glutaraldehyde (BSAG) glue while maintaining excellent cell viability.

UNASSIGNED: To evaluate a newly developed microscale quantitative suspension test compared to the existing standard suspension test using determination of the bactericidal and yeasticidal activity of glutaral as one step to improve the sustainability of disinfectant testing.
UNASSIGNED: The testing principles of the quantitative suspension test according to VAH method 9 (comparable to EN 13727) was used as a standard suspension test using 8.0 mL product test solution, 1.0 mL organic load and 1.0 mL test suspension. In addition, a micro-scale suspension test was performed in 96-well plates with 160 µL product test solution, 20 µL organic load and 20 µL test suspension. S. aureus ATCC 6538, P. aeruginosa ATCC 15442 and C. albicans ATCC 10231 were test organisms. Glutaral was tested at concentrations of 0.05%, 0.1%, 0.2% and 0.3% with exposure times of 1, 5 and 15 min. Polysorbate 80 (30 g/L), lecithin (9 g/L), L-histidine (1 g/L) and glycine (10 g/L) were used as validated neutralizers. After serial dilution of the disinfectant-neutralizer-mixture, plates were incubated for 48 h at 36°C (bacteria) or 72 hours at 30°C (C. albicans) and colony forming units (cfu) counted. The lg reduction was calculated as the difference between the results of the water control and the disinfectant at the end of the exposure time. All experiments were done in triplicate under clean conditions. Means of lg reduction were compared with the unpaired t-test, p<0.05 was considered to be significant.
UNASSIGNED: Sufficient bactericidal activity according the VAH test requirements of at least 5 lg was found with both methods in 16 data sets of 24 data sets in total, and insufficient bactericidal activity of less than 5 lg was found with both methods in 7 data sets. In one data set, the mean lg reduction was above 5 lg with the microscale method and <5 lg with the VAH method, with no significant difference between the data sets (p=0.3096; 0.2% glutaral, 1 min, P. aeruginosa). A sufficient yeasticidal activity of at least 4 lg was found with both methods in one data set, an insufficient yeasticidal activity of less than 4 lg was found with both methods in 8 data sets. With one exception, no significant differences were detected between the two methods below the efficacy threshold.
UNASSIGNED: The microscale quantitative suspension test proved to provide results similar to those of VAH method 9 when the bactericidal and yeasticidal activity of glutaralwas evaluated, with 32 out of 33 evaluations yielding consistent results in terms of efficacy. Its suitability should be confirmed with additional bacterial species, additional biocidal active substances and in other laboratories.
UNASSIGNED: Evaluierung eines neu entwickelten Mikro-Suspensionstests im Vergleich zur bisherigen Standardmethode am Beispiel der Bestimmung der bakteriziden und levuroziden Wirkung von Glutaral als ein Schritt auf dem Weg zu mehr Nachhaltigkeit in der Desinfektionsmittel-Testung.
UNASSIGNED: Die VAH-Methode 9 wurde als Standard-Suspensionstest mit 8,0 mL Produkttestlösung, 1,0 mL organischer Belastung und 1,0 mL Testsuspension verwendet. Darüber hinaus wurde ein Mikroskala-Suspensionstest (Mikromethode) in 96-Well-Platten mit 160 µL Produkttestlösung, 20 µL organischer Belastung und 20 µL Testsuspension durchgeführt. Als Testorganismen dienten S. aureus ATCC 6538, P. aeruginosa ATCC 15442 und C. albicans ATCC 10231. Glutaral wurde in Konzentrationen von 0,05%, 0,1%, 0,2% und 0,3% mit Expositionszeiten von 1, 5 und 15 min getestet. Polysorbat 80 (30 g/L), Lecithin (9 g/L), L-Histidin (1 g/L) und Glycin (10 g/L) wurden als validierte Neutralisationssubstanzen verwendet. Nach serieller Verdünnung des Desinfektionsmittel-Neutralisator-Gemischs wurden die Platten 48 h bei 36°C (Bakterien) bzw. 72 h bei 30°C (C. albicans) bebrütet und die Kolonie bildenden Einheiten (KbE) gezählt. Die lg-Reduktion wurde als Differenz zwischen den Ergebnissen der Wasserkontrolle und des Desinfektionsmittels am Ende der Expositionszeit berechnet. Alle Experimente wurden in dreifacher Ausführung bei geringer Belastung durchgeführt. Die Mittelwerte der lg-Reduktion wurden mit dem ungepaarten t-Test verglichen, wobei ein p-Wert <0,05 als signifikant angesehen wurde.
UNASSIGNED: Eine ausreichende bakterizide Wirkung von mindestens 5 lg wurde mit beiden Methoden in 16 Datensätzen von insgesamt 24 Datensätzen (je als Mittelwert der Dreifachbestimmung) gefunden, eine unzureichende bakterizide Wirkung von <5 lg wurde mit beiden Methoden in 7 Datensätzen gefunden. In einem Datensatz lag die mittlere lg-Reduktion mit der Mikromethode über 5 lg und mit der VAH-Methode unter 5 lg, wobei kein signifikanter Unterschied bestand (p=0,3096; 0,2% Glutaral, 1 min, P. aeruginosa). Eine ausreichende levurozide Wirkung von mindestens 4 lg wurde mit beiden Methoden in einem Datensatz gefunden, eine unzureichende levurozide Wirkung von weniger als 4 lg wurde mit beiden Methoden in 8 Datensätzen gefunden. Unterhalb der Wirksamkeitsgrenze konnten mit einer Ausnahme keine signifikanten Unterschiede der beiden Methoden festgestellt werden.
UNASSIGNED: Die Mikromethode des quantitativen Suspensionsversuchs lieferte in 32 von 33 Versuchsansätzen identische Ergebnisse wie die VAH-Methode 9, wenn die bakterizide und levurozide Wirkung von Glutaral im Hinblick auf das Erreichen- oder Nichterreichen der Wirksamkeitsgrenze bewertet wird. Die Eignung der Methode sollte mit zusätzlichen Bakterienspezies, weiteren bioziden Wirkstoffen und in zusätzlichen Labors bestätigt werden.