Method For Long-term Storage Research Articles

Genetically engineered bacterial biofilm materials enhances portable whole cell sensing

In recent years, whole-cell biosensors (WCBs) have emerged as a potent approach for environmental monitoring and on-site analyte detection. These biosensors harness the biological apparatus of microorganisms to identify specific analytes, offering advantages in sensitivity, specificity, and real-time monitoring capabilities. A critical hurdle in biosensor development lies in ensuring the robust attachment of cells to surfaces, a crucial step for practical utility. In this study, we present a comprehensive approach to tackle this challenge via engineering Escherichia coli cells for immobilization on paper through the Curli biofilm pathway. Furthermore, incorporating a cellulose-binding peptide domain to the CsgA biofilm protein enhances cell adhesion to paper surfaces, consequently boosting biosensor efficacy. To demonstrate the versatility of this platform, we developed a WCB for copper, optimized to exhibit a discernible response, even with the naked eye. To confirm its suitability for practical field use, we characterized our copper sensor under various environmental conditions—temperature, salinity, and pH—to mimic real-world scenarios. The biosensor-equipped paper discs can be freeze-dried for deployment in on-site applications, providing a practical method for long-term storage without loss of sensitivity paper discs demonstrate sustained functionality and viability even after months of storage with 5 μM limit of detection for copper with visible-to-naked-eye signal levels. Biofilm-mediated surface attachment and analyte sensing can be independently engineered, allowing for flexible utilization of this platform as required. With the implementation of copper sensing as a proof-of-concept study, we underscore the potential of WCBs as a promising avenue for the on-site detection of a multitude of analytes.

Effects of cysteine on goat sperm quality in cryopreservation

Cryopreservation is an effective method for long-term storage of sperm. It is essential to investigate the optimal conditions for preserving semen for the purpose of artificial insemination. Cysteine has been proven to reduce the extent of sperm damage caused by oxidative stress during cryopreservation. The aim of this study was to determine the concentration of cysteine required for cryopreservation of goat semen. The experiment was carried out on 2 bucks with 4 treatments, each treatment repeated 8 times. Goat semen was diluted with cryopreservation medium supplemented with cysteine at 4 concentrations: 0 mM, 2 mM, 5 mM, and 10 mM. The sample was transferred to a straw at 0.5 mL, then stored in a liquid nitrogen container. The samples were then thawed, and the sperm quality was evaluated after 72 hours of storage. The results showed that the treatment with 5 mM cysteine showed the best sperm quality results, and the difference was statistically significant with the rest of the treatments (P < 0.05). Specifically, the overall motility, viability, and membrane integrity of spermatozoa in the most optimal treatment were: 82.21%, 90.71%, and 76.09%, respectively. In summary, the study showed that adding a 5 mM concentration of cysteine to the cryopreservation medium significantly enhanced sperm quality

A new strategy to improve the quality of frozen chicken wings: High voltage electrostatic field combined with phosphorus-free water retaining agent

Freezing is a commonly used method for long-term storage of chicken wing products, of which disadvantages are mainly the product damage caused in the process. The aim of this study was to improve the freezing quality of chicken wings with a combination of phosphorus-free water retaining agent (WRA) and high-voltage electrostatic field (HVEF). The effect of WRA acting at different HVEF intensities (0, 1, 3, and 5 kV/cm) on the quality attributes of frozen chicken wings was investigated in 0, 7, 14, 21, 28 and 35 days of frozen storage. The results showed that WRA had functional properties of significantly improving the water holding capacity (WHC), color and texture properties, and fat stability of frozen chicken wing samples. The application of HVEF on this basis helped to promote the absorption of WRA and inhibit oxidative deterioration of chicken wing samples during frozen storage. Meanwhile, the combination of HVEF at 3 kV/cm was more prominent in terms of improvement in WHC, moisture content, color, protein secondary structure and microstructure integrity. This advantage had been consistently maintained with the extension of storage time. Overall, WRA combined with HVEF of 3 kV/cm can be used as an effective strategy to improve the freezing quality of chicken wing samples and has the potential to maintain the frozen chicken wing samples quality for a long time.

ВЫБОР МОДЕЛИ И АРХИТЕКТУРЫ НЕЙРОННОЙ СЕТИ ДЛЯ СИСТЕМЫ ТЕХНИЧЕСКОГО ЗРЕНИЯ ДЕТЕКЦИИ КОРНЕПЛОДОВ САХАРНОЙ СВЁКЛЫ

The use of a technical vision system, aimed at ensuring greater safety of sugar beet roots during harvesting and storage by analyzing raw materials arriving at factories, is considered among the methods of long-term storage. The process of distribution of trucks at the receiving point of sugar factories is considered by humans in the work. The purpose of the work is to develop a method for detecting sugar beet roots on an image of the surface of a truck embankment at the receiving point of sugar factories. A neural network was chosen as the raw material recognition method due to the extremely diverse nature of the resulting images, which recognition using a threshold transformation cannot cope with. Algorithms (options such as SSD, YOLO, R-CNN) and architectures (options such as AlexNet, VGGNet, GoogleNet, ResNet) of various neural networks are considered. The most suitable neural network for the required tasks has been identified. The optimal size of the database for training has been determined. As a result of training and testing the neural network, the need to create additional filters was identified. Filters have been created and described that clarify the work of the neural network: filtering out “stuck together” objects, objects with low class membership, objects with an impossible area (too small or large), as well as with an aspect ratio of less than 0.2 or more than 5. A neural network capable to find a sufficient number of sugar beet roots in incoming images and to meet the requirements for high-quality functioning of the technical vision system, was trained based on the results of the work performed.

ПРОГРАММНО-АЛГОРИТМИЧЕСКОЕ ОБЕСПЕЧЕНИЕ ИНТЕЛЛЕКТУАЛЬНОЙ СИСТЕМЫ ТЕХНИЧЕСКОГО ЗРЕНИЯ ДЛЯ ОПРЕДЕЛЕНИЯ ПАРАМЕТРОВ КОРНЕПЛОДОВ САХАРНОЙ СВЕКЛЫ ПРИ СОРТИРОВКЕ ПЕРЕД УКЛАДКОЙ НА ХРАНЕНИЕ

The application of methods of long-term storage of sugar beet for a period of more than 2 months is justified. It has been found that small root crops are more susceptible to temperature fluctuations and relative humidity of the environment, which leads to a change in the partial pressure of water vapor between the surface of sugar beet and the surrounding air. During storage in a sugar beet mound, the relative humidity reaches from 90 to 95% due to the removal of moisture from the surface of root crops, which is a source of beet mass losses. The criteria for the size of sugar beet root crops have been determined. The necessity of creating a method for sorting trucks at the receiving point of sugar factories is shown. It was revealed that when determining the requirements for sugar beet entering storage, it is necessary to take into account, in addition to physical and chemical parameters, the value of the specific surface area of the root crop. Therefore, it is recommended to send large root crops weighing more than 570 g to kagats. The purpose of the article is formulated, which is to develop software and algorithmic support for determining the parameters of sugar beet root crops when sorting trucks. The process of distribution of trucks at the receiving point of sugar factories by man at the present time is described. A block diagram of the algorithm of the intelligent vision system program is presented and described. The features of the created software are described, such as working with sensors, processing software or hardware errors. According to the results of the study, an algorithm for the operation of the program and software of an intelligent vision system for determining the parameters of sugar beet root crops have been developed [1].

A holistic approach to the total energy and cost for carbon capture and sequestration

Carbon capture and sequestration from a stationary source comprises four distinct engineering processes: separation of CO2 from the other flue gases, compression, transportation, and injection into the chosen storage site. An analysis of the thermodynamic and transport properties of CO2 shows that dissolving this gas in seawater at depths more than 600 m is, most likely, an optimal long-term storage method; and that for transportation, the CO2 must be in the denser supercritical state at pressures higher than 7.377 MPa. The separation, compression, transportation, and injection processes require significant energy expenditures, which are determined in this paper using realistic equipment efficiencies, for the cases of two currently in operation coal power plants in Texas. The computations show that the total energy requirements for carbon removal and sequestration are substantial, close to one-third of the energy currently generated by the two power plants. The cost analysis shows that two parameters – the unit cost of the pipeline and the discount factor of the corporation – have a very significant effect on the annualized cost of the CCS process. Doubling the unit cost of the pipeline increases the total annualized cost of the entire CCS project by 36% and increasing the discount rate from 5% to 15% increases this annualized cost by 32%.

Impact of different storage conditions with combined use of ethylene blocker on ‘Shalimar’ apple variety

This research investigates the impact of storage conditions on the quality and preservation of 'Shalimar' apples, a relatively new cultivar known for its resistance to apple scab and powdery mildew. The study explores the efficacy of different storage techniques such as regular atmosphere (RA), controlled atmosphere (CA), and dynamic controlled atmosphere with CO2 Monitoring (DCA-CD), as well as the integration of 1-methylcyclopropene (1-MCP) at different storage temperatures (1 °C and 3 °C). Various fruit quality parameters were monitored under different storage conditions, including firmness, titratable acidity, total soluble solids, background color, respiration, ethylene production, and volatile compounds. The results indicate that the controlled atmosphere (CA) at 1 °C emerges as an efficient method for long-term storage. However, it is noted that CA storage may impact the apple aroma, emphasizing the need for a balance between preservation and consumer acceptability. On the other hand, DCA-CD at variable temperatures (approximately 2.5 °C) offers a promising approach for maintaining fruit quality and a higher concentration of volatile compounds. Integrating 1-MCP enhances firmness, but its impact varies across storage conditions. Principal component analysis (PCA) provides insights into the relationships between storage conditions, fruit quality, and volatile compounds. This study contributes valuable insights into optimizing storage strategies for ‘Shalimar’ apples, addressing sustainability and quality preservation in apple production.

A CONCEPTUAL FRAMEWORK FOR THE LONG-TERM STORAGE OF UNUSED FOOD FOR THE PURPOSE OF CREATING FOOD RESERVES AND PREVENTING FOOD WASTE IN POLAND

The goal of this study is to create a theoretical model for the assessment of the least resource-intensive storage methods for the buffer stocks. The subject of the study was the available literature on food waste and food preservation methods. Food waste is often mentioned in the context of food security. Meanwhile, research on food waste mainly focuses on ex-post management of food waste rather than reducing food waste in the future. Thus, research on food waste tends towards energy security rather than food security. The bibliometric analysis shows that most of the research conducted focuses on the proper functioning of the supply chain and secondarily on economic food security. Therefore, the paper chooses to link the relevant elements of the analysis of food stock research to possible ways of processing food for long-term storage, based on the literature review. This is a preliminary analysis carried out using the expert method. This may allow some food to be processed into long-term food reserves, whose role is to stabilize food prices and make efficient use of resources in the value chain. To make proper use of such food, its processing and storage must be economically viable. According to this preliminary study, vacuum sealing may be the most efficient of the studied long-term storage methods, although it is not as durable as other methods.

Comparative hepato-ameliorative effects of Bambusa nutans fresh and fermented shoot extracts on STZ induced diabetic LACA mice

Bamboo shoots are nutritionally rich source of antioxidants and bioactive compounds with immense therapeutic potentials. The fresh shoot is acrid and needs to be processed to make it palatable. Fermentation is one the best processing methods for long term storage and make the shoot palatable and enhance taste. This study aims to assess the prophylactic hepatoprotective effects of fresh and fermented B. nutans shoot aqueous extract (200 mg/kg b.w.) in STZ induced diabetic LACA mice. Both extracts effectively improved body weight loss, hyperglycemia, and hepatomegaly. Fresh shoot reduced LDH activity and LPO level by 26.1% and 46.6%, while fermented shoot reduced them by 51.5% and 55.8%, respectively. The fermented shoot extract group demonstrated a noteworthy decrease in liver enzymes (SGPT, SGOT, ALP, and bilirubin levels) and an increase in albumin and A/G ratio, with more substantial improvements compared to the group treated with fresh extract. Additionally, the extracts enhanced antioxidant activities and showed histological improvements in hepatocytes and central vein structure. The findings indicate that both fresh and fermented B. nutans extracts are non-toxic and possess hepatoprotective potential in hyperglycaemic liver dysfunction, with fermented shoot extract exhibiting superior efficacy suggesting its potential as a therapeutic agent for hyperglycemic liver conditions.

Полисахариды базидиальных грибов повышают качество репродуктивных клеток быков при замораживании

The global decline in the animal and plant species diversity is among the key environmental problems of the modern world. One possible way to solve this problem is to develop advanced reproductive technologies using gametes to restore genetic diversity. Cryobanks play an important role in this. The traditional method of long-term storage of reproductive cells is their cryopreservation at –196оC using cryoprotective media based on synthesized substances (glycerin, dimethyl sulfoxide, etc.). The reason for searching new effective substitutes is cytotoxicity, impaired fertility and other disadvantages when using traditional cryoprotectors. In addition, it is relevant to expand the temperature range of biomaterial storage, in particular using the conditions of electric freezers. The wide range of biological effects of polysaccharides of basidiomycetes allowed us to make an assumption about the effectiveness of their use in the composition of the medium for cell cryopreservation. This paper presents the results of a comparative study of the effectiveness of polysaccharides of xylotrophic basidiomycetes in the composition of the medium for storage of the Holstein bull semen. The semen was frozen to –5оC and storaged at the specified temperature for 7 days in AndroMed® (Minitübe, Germany) – certified extender for freezing the semen of bulls and other ruminants. Additional introduction into its composition of polysaccharides from the basidiomycetes Hericium erinaceus BP16 / Ganoderma applanatum GA significantly improves the quality of reproductive cells in the used cryopreservation technology.

Agar dehydration: a simple method for long-term storage of Acanthamoeba spp. collection at room temperature.

This study describes dehydration of agar containing cysts as a novel and inexpensive method for long-term storage of Acanthamoeba spp. collections at room temperature. Five hundred microliters of axenically cultured Acanthamoeba spp. trophozoites (106 cells/mL) in PYG media or 150µl of amoeba suspension (106 cells or cysts/mL) from monoxenic plate culture was spread onto the surface of non-nutritive agar (NNA, 2-3-mm thick) without or with a layer of heat-inactivated Escherichia coli, respectively. The plates were sealed and incubated at 30°C. After the encystment, the Parafilm® was removed, and the plates were kept at the same temperature until the NNA was completely dehydrated. The dehydrated cyst-containing NNA was cut in rectangles and stored in airtight tubes at room temperature for up to 3years. Cyst viability was assessed by inoculating them in fresh NNA with a layer of E. coli and in PYG followed by incubation at 30°C. One hundred percent of samples from all specimens (19) stored over the 3years allowed new cultures to be re-established; however, two strains showed reduced viability, at 66.7% and 62.5%, after 2years of room temperature storage. One hundred percent of the cyst samples produced axenically and maintained in dry NNA allowed the re-establishment of axenic cultures through direct incubation in PYG, with excystment occurring within 24 or 48h. For the first time, we report the dehydration of cyst-containing agar as an economical and effective method for the long-term storage of Acanthamoeba spp. collections at room temperature. It enables the creation of large collections using reduced space and economical transport of Acanthamoeba strains, in addition to allowing better organization of the collection.

Cryopreservation of Large Number of Human Hematopoietic Cells – A Model for Research Space with Limited Resources

Unlike cell lines, cells from primary human tissues are valuable, requiring storage for long-term use. Large number of primary cells require the most efficient method of shipment, when relevant, and cryopreservation to preserve the viability and function. Shipping of cells could be determined by the specific experimental question. These issues are particularly important for primary cells such as hematopoietic stem cells, which cannot expand in vitro. There is minimum issues when cryopreserving relatively small number of cells from tissues such as umbilical cord blood and bone marrow aspirates. However, cryopreservation of >200 × 109 primary cells comes with challenges to identify the most efficient method for long-term storage. Here we report on processes to achieve efficient cell health and recovery of hematopoietic cells from mobilized peripheral blood cells (MPBs). We also determined overnight shipment of MPBs led to overall outcomes when shipped in the cold, as compared to room temperature. We found that cryopreservation of 50 × 106 cells in 2 mL led to maximum recovery of hematopoietic cell subsets. The implication for these conditions to achieve efficient long-term storage is discussed. These methods will benefit small research laboratories such as those at academic settings and start-up companies with limited resources.

A comparison of raspberry freezing-damage during preservation in isochoric and isobaric conditions.

Fruits are perishable, thus it's crucial to have an efficient preservation technique that can increase storage time while keeping physical quality and nutritional attributes in order to avoid wastage. The majority of methods for long-term storage require refrigeration. In this investigation, we assess the viability of isochoric freezing as a different technique of raspberry (Rubus idaeus L.) preservation. Raspberries were subjected to different storage conditions: isochoric freezing at -4°C, conventional isobaric settings at +3°C (refrigerator), -21°C (freezer), and -4°C with a trehalose solution in a plastic bag. The study assessed changes in weight loss, visual appearance, color, hardness, °Brix values, and pH over a seven-day period. Key findings reveal that raspberries subjected to isochoric freezing below the freezing point of water experienced minimal weight loss after seven days. Visual appearance, color, hardness, °Brix values, and pH were comparable to fresh raspberries, indicating minimal alteration. These results suggest that isochoric freezing shows potential as a preservation method that maintains the physical and chemical properties of raspberries similar to fresh fruit. Implementing diverse preservation techniques tailored to raspberries may contribute to environmental sustainability by reducing food wastage and the associated environmental impact.

Comparative leaf structural analysis of Nepeta nuda l. Plantlets, regenerated from cryopreserved shoot meristem and ex vitro-adapted plants

The leaf anatomy and chloroplast ultrastructure of Nepeta nuda L. plantlets regenerated in vitro from cryopreserved shoot apical meristem and in vitro-micropropagated plantlets were studied comparatively to assess whether cryoprocedure affected leaf morphogenesis. Both postcryo and in vitro plantlets failed to develop a distinguishable palisade layer, making the mesophyll appear homogeneous. Significant damage to the chloroplast envelope and substantial thylakoid ruptures were also observed. We assumed that the specific in vitro conditions more likely affected the structures than the cryotreatment itself. Light and transmission electron microscopy observations were also carried out on newly formed leaves of ex vitro-adapted plants. The examined leaf features were similar to those in the in situ plants – bifacial leaf lamina, double-layered palisade parenchyma, loosely arranged spongy parenchyma cells, and chloroplasts with intact envelope and evenly distributed throughout the stroma internal membrane system. The obtained histological and ultrastructural results revealed the retained morphogenetic potential of N. nuda plants and proved cryopreservation as a suitable method for long-term storage.

Enhancing Viability of Human Embryonic Stem Cells during Cryopreservation via RGD-REP-Mediated Activation of FAK/AKT/FoxO3a Signaling Pathway.

Cryopreservation is a crucial method for long-term storage and stable allocation of human pluripotent stem cells (hPSCs), which are increasingly being used in various applications. However, preserving hPSCs in cryogenic conditions is challenging due to reduced recovery rates. To address this issue, the Arginine-Glycine-Aspartate (RGD) motif was incorporated into a recombinant elastin-like peptide (REP). Human embryonic stem cells (hESCs) were treated with REP containing RGD motif (RGD-REP) during suspension and cryopreservation, and the survival rate was analyzed. The underlying mechanisms were also investigated. The addition of RGD-REP to the cryopreservation solution improved cell survival and pluripotency marker expression. The improvement was confirmed to be due to the activation of the FAK-AKT cascade by RGD-REP binding to hESC surface interin protein, and consequent inhibition of FoxO3a. The inactivation of FoxO3a reduced the expression of apoptosis-related genes, such as BIM, leading to increased survival of PSCs in a suspension state. RGD-REP, as a ligand for integrin protein, improves the survival and maintenance of hPSCs during cryopreservation by activating survival signals via the RGD motif. These results have potential implications for improving the efficiency of stem cell usage in both research and therapeutic applications.

Development of Cryopreservation Technique for Meristems of Syringa vulgaris L. Cultivars

Cryopreservation is considered to be one of the most effective methods for long-term storage of plant genetic resources, particularly for ornamental species. However, there is a very little research on cryopreservation of lilacs. In this study, for the first time the cryopreservation protocol (a variation of a pregrowth-dehydration method) was successfully applied to two cultivars of Syringa vulgaris: ‘Aucubaefolia’ and ‘Polina Osipenko’. Explants of both cultivars were able to withstand the different steps of the protocol, and high survival and regrowth percentages were obtained after exposure to liquid nitrogen (67–100% and 63–88%, respectively). The current study is mainly focused on the preculture conditions of the applied method. Based on our results, we propose the use of paclobutrazol (PBZ) with the combination of 6-benzylaminopurine (BAP) and thidiazuron (TDZ) in the preculture medium for increasing explant tolerance to subsequent dehydration and freezing. During post-LN recovery, the explants appeared morphologically normal, and after 12–16 weeks after thawing, they were propagated and cultured as normal plantlets. Therefore, the reported method is effective for long-term storage of lilac meristems and could be used to create a cryobank of achievements in lilac breeding.

Hemolysis and hypersensitive tests ease culture collection management of antagonistic bacteria

A biosafety assessment is a crucial first step in the management of microbial culture collection to screen and determine unexpected potential plant and human pathogenic bacteria. It is common to collect and store as many fresh culture collections from natural resources before being further evaluated for antagonist bacteria. As a result, a bulk of isolates must be preserved which required more effort and budget. Safety evaluations based on the hemolysis and hypersensitive reactions offer simple tests to ease culture collection management of antagonist bacteria. The study aimed to evaluate the safety of bacterial culture collection for their hemolysis and hypersensitive reactions. Ninety-five isolates of rhizosphere and endophytic bacterial isolates from the culture collections of the Department of Plant Protection-IPB University, Indonesian Industrial and Beverages Crops Research Institute, and Indonesian Spice and Medicinal Crops Research Institute, were evaluated their safety using the hemolysis and hypersensitive tests. The hemolysis test was conducted using blood agar media, from which isolates with a negative (?) reaction were then tested for the hypersensitivity reaction on tobacco leaves. Bacterial isolates passed from both hemolysis and hypersensitivity tests were then preserved by the lyophilization method for long-term storage of culture collection. Based on the hemolysis test, 68 out of 95 bacterial isolates (71.57%) were found to be positive (? or ?) reactions. The hypersensitive test showed that 22 of 27 negative hemolysis isolates did not trigger hypersensitivity reactions in tobacco leaves, therefore, they were preserved by lyophilization. The study indicated that a high number of bacterial isolates in the present collection, 68 positive hemolysis, and 5 hypersensitive, need to be re-evaluated due to their safety concerns. The present study highlights the importance of biosafety tests performed in an early stage before the to permanent collection of antagonist isolates.

Methods for Long-Term Storage of Pure Cultures of Macrofungi

Basidiomycetous macrofungi have significant biotechnological potential and are promising objects for use in va-rious industrial sectors, such as food production, pharmaceuticals, the production of active compounds and polysaccharides. The industrial use of macrofungi implies the presence of large collections of cultures using sto-rage protocols that ensure the preservation of viability, reproduction, genetic stability and the ability to produce active compounds. With the expansion of the list of industrially used species, it is advisable to develop new protocols for the storage of strains and optimize the existing ones for new, promising types of macrofungi. It seems necessary to study in detail the effect of long periods of storage on morphological and cultural characteristics, genetic stability, enzymatic activity, and the ability to form sexual structures.

Long-term preservation and genetic stability of entomopathogenic fungal species

Entomopathogenic fungi (EPF) preservation aims to maintain valuable characteristics. Growth, conidiation and genetic stability of eight species of EPF were evaluated in six preservation methods for up to 8.2 years. Cryopreservation at −196 °C, freeze-drying, and ultra-freezing at −70 °C resulted as the best methods for long-term storage.

Influence of Storage Conditions on Decellularized Porcine Conjunctiva

Porcine decellularized conjunctiva (PDC) represents a promising alternative source for conjunctival reconstruction. Methods of its re-epithelialization in vitro with primary human conjunctival epithelial cells (HCEC) have already been established. However, a long-term storage method is required for a simplified clinical use of PDC. This study investigates the influence of several storage variants on PDC. PDC were stored in (1) phosphate-buffered saline solution (PBS) at 4 °C, (2) in glycerol-containing epithelial cell medium (EM/gly) at -80 °C and (3) in dimethyl sulfoxide-containing epithelial cell medium (EM/DMSO) at -196 °C in liquid nitrogen for two and six months, respectively. Fresh PDC served as control. Histological structure, biomechanical parameters, the content of collagen and elastin and the potential of re-epithelialization with primary HCEC under cultivation for 14 days were compared (n = 4-10). In all groups, PDC showed a well-preserved extracellular matrix without structural disruptions and with comparable fiber density (p ≥ 0.74). Collagen and elastin content were not significantly different between the groups (p ≥ 0.18; p ≥ 0.13, respectively). With the exception of the significantly reduced tensile strength of PDC after storage at -196 °C in EM/DMSO for six months (0.46 ± 0.21 MPa, p = 0.02), no differences were seen regarding the elastic modulus, tensile strength and extensibility compared to control (0.87 ± 0.25 MPa; p ≥ 0.06). The mean values of the epithelialized PDC surface ranged from 51.9 ± 8.8% (-196 °C) to 78.3 ± 4.4% (-80 °C) and did not differ significantly (p ≥ 0.35). In conclusion, all examined storage methods were suitable for storing PDC for at least six months. All PDC were able to re-epithelialize, which rules out cytotoxic influences of the storage conditions and suggests preserved biocompatibility for in vivo application.