Sterilization Methods Research Articles

A Review of Chemical Castration in Domestic Animals

This review article discusses the use of numerous chemical agents supplied through various routes to regulate the population of several animal species, including dogs, guinea pigs, rabbits, rams, and rats. While surgery is the safest and most effective procedure, it is also the most expensive. Therefore, non-surgical sterilization methods that would make male sterilization cheap, simple, and quick for sterilizing a large number of male animals in a short amount of time were introduced in an effort to slow down the increase in the animal population effectively.

The Impact of Opportunistic Salpingectomy on Ovarian Reserve: A Systematic Review.

Background: In the last decade, increasing evidence has suggested that high-grade serous ovarian cancers may have their origin in the fallopian tube rather than the ovary. This emerging theory presents an opportunity to prevent epithelial ovarian cancer by incorporating prophylactic bilateral salpingectomy into all surgical procedures for average-risk women. The aim of this review is to investigate the hypothesis that bilateral salpingectomy (BS) may have a negative impact on ovarian reserve, not only following hysterectomy for benign uterine pathologies but also when performed during cesarean sections as a method of sterilization or as a treatment for hydrosalpinx in Assisted Reproductive Technology interventions. Methods: PubMed, Medline, Google Scholar, and Cochrane were searched for original studies, meta-analyses, and opinion articles published between 2014 and 2024. Results: Out of 114 records from the database search, after the removal of duplicates, 102 articles were considered relevant for the current study. Conclusions: Performing opportunistic salpingectomy seems to have no adverse impact on ovarian function in the short term. However, because there is an existing risk of damaging ovarian blood supply during salpingectomy, there are concerns about potential long-term adverse effects on the ovarian reserve, which need further investigation.

Characterization of the novel phage vB_BceP_LY3 and its potential role in controlling Bacillus cereus in milk and rice

Bacillus cereus is a foodborne pathogen that induces vomiting and diarrhea in affected individuals. It exhibits resistance to traditional sterilization methods and has a high contamination rate in dairy products and rice. Therefore, the development of a new food safety controlling strategy is necessary. In this research, we isolated and identified a novel phage named vB_BceP_LY3, which belongs to a new genus of the subfamily Northropvirinae.This phage demonstrates a short latency period and remains stable over a wide range of temperatures (4–60 °C) and pH levels (4–11). The 28,124 bp genome of LY3 does not contain any antibiotic-resistance genes or virulence factors. With regards to its antibacterial properties, LY3 not only effectively inhibits the growth of B. cereus in TSB (tryptic soy broth), but also demonstrates significant inhibitory effects in various food matrices. Specifically, LY3 treatment at 4 °C with a high MOI (MOI = 10,000) can maintain B. cereus levels below the detection limit for up to 24 h in milk. LY3 represents a safe and promising biocontrol agent against B. cereus, possessing long-term antibacterial capabilities and stability.

Optimalisation of in vitro sterilisation methods for North Sumatra local garlic (Allium Sativum L.)

Abstract The establishment stage is critical to the success of plant tissue culture. Each plant tissue has unique tissue surface characteristics that interact with various natural microbes. The goal of this study was to find a sterilisation method that is effective at removing contamination while not damaging or inhibiting explant regeneration. In this study, Completely Randomized Design (CRD) factorial with 2 factors was used. The first factor was the disinfectant, namely T1 (Benzalkonium chloride 0.5%), T2 (Nordox 6 g/L 0.6%), and T3 (Clorox 10%). The second factor is the type of media, consisting of M1 (BDS supplemented with 1.8 μM/L 2,4-D and 9.2 μM/L Kinetin), M2 (BDS supplemented with 9 μM/L 2,4-D and 9.2 μM/L Kinetin), M3 (MS supplemented with 9 μM/L 2,4-D and 4.6 μM/L Kinetin), and M4 (MS media supplemented with 1.3 μM/L 2,4-D and 9.2 μM/L Kinetin. The observed parameters were the percentage of contamination, the survival rate, the type of contamination, the percentage of callus growing, weight and diameter. The T2 treatment was the most effective in reducing contamination and had the highest survival rate. T3 treatment resulted in the highest callus regeneration percentage, callus weight, and callus diameter, but also the highest level of contamination.

A Male Surgical Contraceptive Method Based on Recommendations and Techniques Used in Vasectomy

Background: Vasectomy is a well-established method of male sterilization, offering a reliable and permanent contraceptive solution. Despite its effectiveness, the procedure remains underutilized due to limited counseling and awareness among patients. Objective: The objective of this study was to evaluate the efficacy and safety of a standardized vasectomy technique based on the 2012 American Urological Association (AUA) guidelines and to identify factors influencing postoperative outcomes and patient satisfaction. Methods: This prospective cohort study was conducted at the Department of Zoology, Rawalpindi Women University, from January 2022 to December 2023. A total of 150 male patients aged 25 to 50 years seeking permanent contraception were enrolled. Preoperative evaluations included detailed medical history, physical examination, and baseline semen analysis. The vasectomy procedures involved isolation, division, and management of the vasal ends using techniques such as proximal fascial interposition and thermal luminal fulguration. Postoperative care included instructions on scrotal support, avoidance of strenuous activities, and use of alternative contraception until azoospermia was confirmed through post-vasectomy semen analysis (PVSA) conducted at three months post-procedure. Data were analyzed using SPSS version 25, with statistical significance set at p < 0.05. Results: The mean age of participants was 37.5 years (range: 25-50 years). The overall efficacy rate was 98.7%, with 140 participants (93.3%) achieving azoospermia and 8 participants (5.3%) having less than 100,000 non-motile sperm/mL at three months post-procedure. Complications included infection (1.3%), hematoma (2.0%), chronic pain (2.7%), and sperm granuloma (0.7%). The mean VAS scores for pain were 2.3 at one week, 1.1 at one month, and 0.5 at three months post-procedure. Patient satisfaction was high, with 95% of participants reporting satisfaction with the procedure. Conclusion: This study demonstrated that vasectomy, when performed using standardized techniques, is a highly effective and safe method of male sterilization with high patient satisfaction and low complication rates. Enhanced preoperative counseling and follow-up are essential to optimize outcomes and increase the utilization of vasectomy as a contraceptive method.

Effects of sterilization and disinfection methods on digitally designed surgical implant guide accuracy: An in vitro study.

Surgical guides are commonly used to assist with dental implant placement. This study investigated the effects of five sterilization and disinfection methods on the accuracy of implant guides. Thirty surgical guides (five in each group) were designed and printed (with digital light processing technology) using different sterilization or disinfection methods categorized into six groups: hydrogen peroxide sterilization (group one); glutaraldehyde sterilization (group two); autoclaving (group three); plasma sterilization (group four); iodophor disinfection (group five); and blank group (group six). Verification was determined using three methods: distance and angle between the cross-shaped marks, deformation after superimposing the guides, and displacement and axial changes in the virtual implant. After disinfection and sterilization, the guides in the autoclaving and iodophor groups showed a more pronounced color change and the guidein the autoclaving group had visible cracks. More significant changes were observed in the H2O2, glutaraldehyde, autoclaving, and iodophor groups regarding deformation after superimposing the guides and the distance and angle between the cross-shaped marks. The average labial deformation values (mm) of the first through fifth groups of guides were 0.283, 0.172, 0.289, 0.153, and 0.188, respectively. All groups were statistically different from the blank group for displacement and axial changes of the virtual implant (p < 0.05). The sizes of almost all surgical guides changed after sterilization and disinfection treatments, with between-group differences. Plasma sterilization was more suitable for surgical guide sterilization because of the smaller deformations after treatment.

Knowledge, Attitude and Practices (KAP) of Sterilization and Disinfection of Health Care Professionals in Bangladesh

&amp;lt;i&amp;gt;Background:&amp;lt;/i&amp;gt; Healthcare professionals face a constant risk of acquiring infections from patients. Exposure to blood, saliva, and sharp instruments increases their susceptibility to various infectious diseases. Proper sterilization and disinfection procedures are crucial for protecting both healthcare workers and patients. &amp;lt;i&amp;gt;Objective:&amp;lt;/i&amp;gt; This study aimed to assess the knowledge, attitude, and practices regarding sterilization and disinfection among healthcare professionals in Bangladesh.&amp;lt;i&amp;gt; Methods&amp;lt;/i&amp;gt;: A cross-sectional study was conducted at the National Institute of Cardiovascular Diseases &amp; Hospital in Dhaka, Bangladesh, from January to June 2023. A total of 81 healthcare professionals were randomly selected and participated in the study after providing verbal consent. Data collection involved a pre-structured questionnaire focusing on knowledge, attitude, and practices related to sterilization and disinfection. Statistical analysis was performed using SPSS software, and results were presented as frequencies and percentages. Ethical clearance was obtained before the study commenced. &amp;lt;i&amp;gt;Results: &amp;lt;/i&amp;gt;The study included healthcare professionals from various backgrounds, with the majority being young adults (21-25 years old). Knowledge assessment revealed a good understanding of sterilization methods, disinfection procedures, post-sterilization instrument management, and waste disposal practices. Additionally, most participants were aware of the hospital&amp;apos;s sterilization protocols and infection prevention policies. Regarding attitudes, a positive response was observed towards regular training for staff, proper use of personal protective equipment (PPE), and adherence to sterilization and disinfection guidelines. However, a minority expressed concerns about reusing disposable items. Practices reflected the positive knowledge and attitudes, with a high percentage of participants following hand hygiene protocols, using PPE, and opting for disposable equipment. However, a small number reported experiencing needle-stick injuries, highlighting a potential gap between knowledge and practice. &amp;lt;i&amp;gt;Conclusions:&amp;lt;/i&amp;gt; the study found that a majority of healthcare professionals in this setting demonstrated good knowledge, positive attitudes, and appropriate practices regarding sterilization and disinfection. However, a small knowledge, attitude, and practice gap was identified, particularly concerning needle-stick injuries. These findings suggest a need for ongoing education and reinforcement of safe practices to ensure optimal infection prevention and control in healthcare facilities.

Diffusion risk analysis and interdiction procedures of transmission of microorganism in the primary cold storage of imported cold chain food in case of novel coronavirus

During the period of COVID-19, the health problems caused by the contamination of imported cold chain food by pathogenic microorganisms attracted widespread attention, which brought new risks and challenges to cold chain products. The traditional liquid disinfection method has obviously been unable to meet the existing disinfection and sterilization needs, and establishing a complete set of cold chain product disinfection system has become the focus of research. This paper takes the process of importing cold chain food from Tianjin's primary cold storage as an example, and proposes the closed-loop cold storage disinfection system of "Human-Cargo-Apparatus-Waste". The establishment of the disinfection system determined the working characteristics of different areas of the primary cold storage and the risk level of virus transmission through on-site analysis and simulated aerosol diffusion experiments. According to the characteristics of different working areas in the cold storage, targeted sealing measures and disinfection techniques are adopted. It can effectively ensure the complete disinfection of cold chain products and avoid the negative impact of disinfection and sterilization methods. The expected research results provide certain technical support for the development and application of safe virus elimination throughout the entire process of imported cold chain.

An evaluation of a Stenotrophomonas maltophilia outbreak due to commercial arterial blood gas collection kit

BackgroundStenotrophomonas maltophilia is a gram-negative bacterium that can cause hospital infections and outbreaks within hospitals. This study aimed to evaluate an outbreak of Stenotrophomonas maltophilia, caused by ready-to-use commercial syringes containing liquid lithium and heparin for arterial blood gas collection in a university hospital.MethodsUpon detecting an increase in Stenotrophomonas maltophilia growth in blood cultures between 15.09.2021 and 19.11.2021, an outbreak analysis and a case-control study (52 patients for the case group, 56 patients for the control group) were performed considering risk factors for bacteremia. Samples from possible foci for bacteremia were also cultured. Growing bacteria were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The genetic linkage and clonal relationship isolates were investigated with pulsed-field gel electrophoresis (PFGE) in the reference laboratory.ResultsIn the case-control study, the odds ratio for the central venous catheter [3.38 (95% confidence interval [CI]: 1.444, 8.705 ; p = 0.006)], for surgery [3.387 (95% confidence interval [CI]: 1.370, 8.373 ; p = 0.008)] and for arterial blood gas collection history [18.584 (95% confidence interval [CI]:4.086, 84.197; p < 0.001)] were identified as significant risk factors. Stenotrophomonas maltophilia growth was found in ready-to-use commercial syringes used for arterial blood gas collection. Molecular analysis showed that the growths in the samples taken from commercial syringes and the growths from blood cultures were the same. It was decided that the epidemic occurred because the method for sterilization of heparinized liquid preparations were not suitable. After discontinuing the use of the kits with this lot number, the outbreak was brought under control.ConclusionsAccording to our results, disposable or sterile medical equipment should be included as a risk factor in outbreak analyses. The method by which injectors containing liquids, such as heparin, are sterilized should be reviewed. Our study also revealed the importance of the cooperation of the infection control team with the microbiology laboratory.

Decoding the Effects of High Hydrostatic Pressure and High-Temperature Short-Time Sterilization on the Volatile Aroma Profile of Red Raspberry Juice.

The loss of distinctive aromas due to sterilization significantly hinders efforts to enhance the sensory quality of fruit and vegetable juices. This study aimed to elucidate the impacts of high-hydrostatic pressure (HHP) and high-temperature short-time (HTST) sterilization methods on the loss of C6 aldehyde aroma-active compounds in red raspberry juice. External standard quantification and quantitative descriptive analysis (QDA) revealed a notable decline in the levels of hexanal and (Z)-3-hexenal following the HHP and HTST treatments (p < 0.05), resulting in a marked attenuation of the grassy aroma characteristic of red raspberry juice. Furthermore, a comprehensive examination of the precursors, pivotal enzymes, intermediates, and downstream aromas within the fatty acid metabolism pathway in different raspberry juice samples indicated that the C6 aldehydes loss induced by HHP and HTST sterilizations was primarily ascribed to the competitive inhibition of β-oxidation and the hindered enzymatic oxidation of fatty acids. These insights suggest that modifying sterilization protocols and enhancing enzymatic stability may help preserve the aroma integrity of raspberry juice. Our findings offer practical guidance for optimizing juice processing techniques to maintain flavor.

Metabolomic insights into Monascus-fermented rice products: Implications for monacolin K content and nutritional optimization.

This study aims to elucidate the detailed metabolic implications of varying monacolin K levels and sterilization methods on Monascus-fermented rice products (MFRPs), acclaimed for their health benefits and monacolin K content. Advanced metabolite profiling of various MFRP variants was conducted using ultrahigh-performance liquid chromatography coupled with tandem time-of-flight mass spectrometry (UHPLC-Q-TOF MS). Statistical analysis encompassed t-tests, ANOVA, and multivariate techniques including PCA, PLS-DA, and OPLS-DA. Notable variations in metabolites were observed across MFRPs with differing monacolin K levels, particularly in variants such as MR1-S, MR1.5-S, MR2-S, and MR3-S. Among the 524 identified metabolites, significant shifts were noted in organic acids, derivatives, lipids, nucleosides, and organic oxygen compounds. The study also uncovered distinct metabolic changes resulting from different sterilization methods and the use of highland barley as a fermentation substitute for rice. Pathway analysis shed light on affected metabolic pathways, including those involved in longevity regulation, cGMP-PKG signaling, and the biosynthesis of unsaturated fatty acids. The research provides critical insights into the complex metabolic networks of MFRPs, underscoring the impact of fermentation substrates and conditions on monacolin K levels and their health implications. This study not only guides the nutritional optimization of MFRPs but also emphasizes the strategic importance of substrate choice and sterilization techniques in enhancing the nutritional and medicinal value of these functional foods.

Characterization of Pseudomonas spp. contamination and in situ spoilage potential in pasteurized milk production process

To investigate the prevalence of Pseudomonas in the pasteurized milk production process and its effect on milk quality, 106 strains of Pseudomonas were isolated from the pasteurized milk production process of a milk production plant in Shaanxi Province, China. The protease, lipase and biofilm-producing capacities of the 106 Pseudomonas strains were evaluated, and the spoilage enzyme activities of their metabolites were assessed by simulating temperature incubation in the refrigerated (7 °C) and transport environment (25 °C) segments and thermal treatments of pasteurization (75 °C, 5 min) and ultra-high temperature sterilization (121 °C, 15 s). A phylogenetic tree was drawn based on 16S rDNA gene sequencing and the top 5 strains were selected as representative strains to identify their in situ spoilage potential by examining their growth potential and ability to hydrolyze proteins and lipids in milk using growth curves, pH, whiteness, Zeta-potential, lipid oxidation, SDS-PAGE and volatile flavor compounds. The results showed that half and more of the isolated Pseudomonas had spoilage enzyme production and biofilm capacity, and the spoilage enzyme activity of metabolites was affected by the culture temperature and sterilization method, but ultra-high temperature sterilization could not completely eliminate the enzyme activity. The growth of Pseudomonas lundensis and Pseudomonas qingdaonensis was less affected by temperature and time, and the hydrolytic capacity of extracellular protease and lipase secreted by Pseudomonas lurida was the strongest, which had the greatest effect on milk quality. Therefore, it is crucial to identify the key contamination links of Pseudomonas, the main bacteria responsible for milk spoilage, and the influence of environmental factors on its deterioration.

Reproductive Characteristics and Suitability of Sterile dead end Knockout Nibe Croaker as a Recipient for Intraperitoneal Germ Cell Transplantation.

The use of sterile recipients is crucial for efficiently producing donor-derived offspring through surrogate broodstock technology for practical aquaculture applications. Although knockout (KO) of the dead end (dnd) gene has been used in previous studies as a sterilization method, it has not been reported in marine fish. In this study, nibe croaker was utilized as a model for marine teleosts that produce small pelagic eggs, and the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (CRISPR/Cas9) system was utilized to produce dnd KO fish. The F1 generation, which carried a nonsense mutation in the dnd gene, was produced by mating founder individuals with wild-type counterparts. Subsequently, the F2 generation was produced by mating the resulting males and females. Among the F2 generations, 24.0% consisted of homozygous KO individuals. Histological analysis revealed that primordial germ cells (PGCs) were present in homozygous KO individuals at 10days post-hatching (dph), similar to wild-type individuals. However, by 20 dph, PGCs were absent in KO individuals. Furthermore, no germ cells were observed in the gonads of both sexes of homozygous KO individuals at 6months old, which is the typical maturity age for wild-type individuals of both sexes. In addition, when cryopreserved donor nibe croaker testicular cells were transplanted, only donor-derived offspring were successfully obtained through the spontaneous mating of homozygous KO recipient parents. Results indicate that dnd KO nibe croaker lacks germ cells and can serve as promising recipients, producing only donor-derived gametes as surrogate broodstock.

Advancing 2D imaging of ammonium for biological application: Planar and nanoparticle-based ion-selective optodes

This study investigates the development and optimization of ammonium-selective chromoionophore-based optodes for two-dimensional (2D) imaging with conventional cameras. Ammonium, vital in various fields like agriculture, ecology, and health, requires accurate measurement. Traditional methods have limitations, leading to the exploration of optical sensors, or optodes, for direct imaging of ammonium gradients. The research covers planar and nanoparticle designs, exploring absorbance and fluorescence readouts with commercial cameras. The study extends to repeatability, response time, and selectivity of the optodes. Planar optodes, utilizing chromoionophores under different background colors, demonstrate improved characteristics with the addition of TiO2. The impact of plasticizer choice on response characteristics, including hysteresis, is explored. Nanoparticle designs using PVC and F127 are compared, with autoclaving identified as the superior sterilization method. The work effectively demonstrates 2D real-time NH4+ visualization using optode nanoparticles in agar gels. Finally, a proof-of-concept was performed to showcase a biological application for identifying urease-producing pathogens (Bacillus subtilis) without relying on pH changes. Overall, this study provides a comprehensive exploration of ammonium-selective optodes with promising applications in environmental monitoring and biological studies.

Effects of autoclaving and disinfection on 3D surgical guides using LCD technology for dental implant

BackgroundSurgical guides can improve the precision of implant placement and minimize procedural errors and their related complications. This study aims to determine how different disinfection and sterilization methods affect the size changes of drill guide templates and the mechanical properties of 3D-printed surgical guides made with LCD technology.MethodsWe produced a total of 100 samples. Forty surgical guides were fabricated to assess the implant drill guides’ surface and geometric properties. We subjected sixty samples to mechanical tests to analyze their tensile, flexural, and compressive properties. We classified the samples into four groups based on each analytical method: GC, which served as the control group; GA, which underwent autoclave sterilization at 121 °C (+ 1 bar, 20 min); GB, which underwent autoclave sterilization at 134 °C (+ 2 bar, 10 min); and GL, which underwent disinfection with 70% isopropyl alcohol for 20 min.ResultThe results show that sterilization at 121 °C and 134 °C affects the mechanical and geometric characteristics of the surgical guides, while disinfection with 70% isopropyl alcohol gives better results.ConclusionOur study of 3D-printed surgical guides using LCD technology found that sterilization at high temperatures affects the guides’ mechanical and geometric properties. Instead, disinfection with 70% isopropyl alcohol is recommended.

Sterilization Method for Borosilicate Glass Vials and Chlorobutyl, Bromobutyl Rubbers for Medical Purposes

For surgical and medical tools to prevent the spreading of infectious microorganisms to patients, disinfection and sterilization must be achieved by the use of disinfectants and sterilization procedures. Health care regulations must determine whether cleaning, disinfection, or sterilization is essential based largely on the item’s intended use because sterilizing all patient care equipment is unnecessary. In this work, successful sterilization of vials and rubbers used for medical purposes has been implemented. It can be claimed that the sequence of moist and dry heat is more practical for sterilizing primary packaging materials used in diagnostic or treatment facilities, especially for borosilicate vials and chlorobutyl, bromobutyl rubbers. It has been shown that the suggested sterilization method provides sterile and endotoxin-free vials and rubbers that can be used for medical purposes. Endotoxins and sterility tests have been implemented for microbiological analysis of borosilicate vials and chlorobutyl, and bromobutyl rubbers. Endotoxin levels in all vials and rubbers tested were within acceptable limits, and no microbial growth was observed in test specimens based on sterility tests. The suggested sterilization method was effective in producing sterile and endotoxin-free vials and rubbers suitable for medical use.

Studies on In vitro Surface Sterilisation and Antioxidants on Pomegranate (Punica granatum L.) cv. Bhagwa

Pomegranate, regarded as the “Fruit of Paradise”, is one of the important fruit crops of tropical and subtropical regions. Pomegranate fruits are delicious and possess significant nutritional and medicinal benefits. Due to the increase in demand, the proliferation of pomegranate through tissue culture is essential to get high-quality planting material. However, microbial contamination in plant tissue culture is one of the bottlenecks for establishing aseptic cultures. Although multiple explant sterilisation methods have been developed for pomegranate, explant sterilisation methods can indeed vary from region to region due to the local environment and the mother plant. In the present study, 1-2 drops of tween 20 (20 min) + 500 mg/L carbendazim (30 min) + 500 mg/L streptomycin sulphate (10 min) + 100 mg/L citric acid (30 min) + 100 mg/L tebuconazole (folicur) (30 min) + 0.1% HgCl2 (1 min) + dipping explant after cutting the edges in sterile water (30 min) + dipping in 500 mg/L PVP (5 min) was found to be optimum in the prevention of microbial contamination with minimal cell death. Nodal segments-initiated callus at 54 days after culture, showing a callus induction percentage of 55.55% and a calli weight of 80 mg/explant.

Enhanced photodynamic inactivation against Escherichia coli O157:H7 provided by chitosan/curcumin coating and its application in food contact surfaces

Sterilisation technologies are essential to eliminate foodborne pathogens from food contact surfaces. However, most of the current sterilisation methods involve high energy and chemical consumption. In this study, a photodynamic inactivation coating featuring excellent antibacterial activity was prepared by dispersing curcumin as a plant-based photosensitiser in a chitosan solution. The coating generated abundant reactive oxygen species (ROS) after light irradiation at 420 nm, which eradicated ≥99.999 % of Escherichia coli O157:H7. It was also found that ROS damaged the cell membrane, leading to the leakage of cell contents and cell shrinkage on the basis of chitosan. In addition, the production of ROS first excited the bacterial antioxidant defence system resulting in the increase of peroxidase (POD) and superoxide dismutase (SOD). ROS levels exceed its capacity, causing damage to the defence system and further oxidative decomposition of large molecules, such as DNA and proteins, eventually leading to the death of E. coli O157:H7. We also found the curcumin/chitosan coating could effectively remove E. coli O157:H7 biofilms by oxidative of extracellular polysaccharides and proteins. All the contributors made the chitosan/curcumin coating an efficient detergent comparable with HClO.

The Impacts of the Sterilization Method and the Electrospinning Conditions of Nanofibrous Biodegradable Layers on Their Degradation and Hemocompatibility Behavior.

The use of electrospun polymeric biodegradable materials for medical applications is becoming increasingly widespread. One of the most important parameters regarding the functionality of nanofiber scaffolds during implantation and the subsequent regeneration of damaged tissues concerns their stability and degradation behavior, both of which are influenced by a wide range of factors (the properties of the polymer and the polymer solution, the technological processing approach, the sterilization method, etc.). This study monitored the degradation of nanofibrous materials fabricated from degradable polyesters as a result of the sterilization method applied (ethylene oxide and gamma irradiation) and the solvent system used to prepare the spun polymer solution. Aliphatic polyesters PCL and PLCL were chosen for this study and selected with respect to the applicability and handling in the surgical setting of these nanofibrous materials for vascular bandaging. The results revealed that the choice of solvent system exerts a significant impact on degradation during sterilization, especially at higher gamma irradiation values. The subsequent enzyme-catalyzed degradation of the materials following sterilization indicated that the choice of the sterilization method influenced the degradation behavior of the materials. Whereas wave-like degradation was evident concerning ethylene oxide sterilization, no such behavior was observed following gamma-irradiation sterilization. With concern for some of the tested materials, the results also indicated the potential for influencing the development of degradation within the bulk versus degradation from the surface of the material. Both the sterilization method and the choice of the spinning solvent system were found to impact degradation, which was observed to be most accelerated in the case of PLCL (L-lactide-co-caprolactone copolymer) electrospun from organic acids and subsequently sterilized using gamma irradiation. Since we planned to use these materials in cardiovascular applications, it was decided that their hemocompatibility would also be tested. The results of these tests revealed that changes in the structures of the materials initiated by sterilization may exert thrombogenic and anticoagulant impacts. Moreover, the microscopic analysis suggested that the solvent system used in the preparation of the materials potentially affects the behavior of erythrocytes; however, no indication of the occurrence of hemolysis was detected.

Clinical Applicable Carboxymethyl Chitosan with Gel-Forming and Stabilizing Properties Based on Terminal Sterilization Methods of Electron Beam Irradiation.

Carboxymethyl chitosan (CMC)-based hydrogels have great potential for clinical applications, but a critical sterilization process must be addressed to bring them to market. Compared to ethylene oxide sterilization or heat sterilization, irradiation sterilization avoids alkylation and heat damage, while available studies on γ-irradiated other polysaccharides show that solution polysaccharides are susceptible to degradation or cross-linking. Aiming at the challenges brought by the γ-irradiation process of polysaccharide aqueous solution, this paper innovatively proposes the lyophilized CMC using electron beam (EB) irradiation, which not only avoids the generation of free radicals in the irradiated water leading to the degradation and cross-linking of polysaccharides but also retains the properties of CMC in terms of gel formation, stabilization, and clinical application. We used FTIR, TG, GPC, and microbial load tests to demonstrate that lyophilized CMC did not have significant changes in structure and molecular weight after EB irradiation, complied with the requirements for sterilization, and still had gel stability, thus proving that lyophilized CMC could be used for EB irradiation and met the requirements for clinical application. Therefore, this work is expected to further advance CMC injectable hydrogels toward clinical applications and provide a new direction for the sterilization processes of other polysaccharide hydrogels.