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Introduction. The rapid spread of coronavirus infection COVID-19 among the population of many countries around the world has contributed to the emergence of many genetic variants of SARS-CoV-2. Compared to previous coronavirus variants, the new Omicron variants have shown a noticeable degree of mutation. Virus inactivation is one of the most important steps in the development of inactivated vaccines. The chemical inactivation agents currently used are β-propiolactone and formaldehyde, but there is no uniform standard for designing and specifying the inactivation process. Objective. Evaluation and comparison of the effectiveness of chemical inactivation of two agents, formaldehyde and β-propiolactone against immunogenicity of the Omicron variant of the SARS-CoV-2 virus. Materials and methods. Nasopharyngeal swabs were used to obtain the SARS-CoV-2 Omicron variant virus. Vero cell culture was used to isolate, reproduce, titrate the virus, and perform a neutralization reaction. The kinetics of studying the inactivation of the virus by chemical agents such as formaldehyde and β-propiolactone was carried out. Results. Studies have been conducted to comparatively evaluate the effectiveness of chemical agents used to inactivate the SARS-CoV-2 virus of the Omicron variant, planned for use in the production of an inactivated whole-virion vaccine. Formaldehyde and β-propiolactone were used as inactivation agents in concentrations of 0.05, 0.1, 0.5% of the total volume of the virus suspension. It has been established that complete inactivation of the virus by formaldehyde in the concentrations used at a temperature of 37 °C occurs within up to 2 hours, and when using beta-propiolactone, within up to 12 hours. Conclusion. Inactivated virus samples have different antigenic activity depending on the concentration of the inactivation agents used. The most pronounced antigenic activity is manifested in samples of the pathogen that were treated with an inactivation agent at a mild concentration of 0.05%. Increasing the concentration of inactivation agent by 5 or more times leads to a significant decrease in the antigenicity of the SARS-CoV-2 virus. With the inactivation modes used, the loss of biological activity of the virus occurs faster and antigenicity is retained largely when treated with formaldehyde.

Relevance. Hemorrhagic fever with renal syndrome (HFRS) is leading among natural focal human diseases in Russia, the causative agents of which - orthohantaviruses - belong to the order Bunyavirales, family Hantaviridae. More than 98% of HFRS cases in Russia are caused by the Puumala virus. It is a serious zoonosis for which there is still no specific treatment. The WHO has not approved a vaccine. The aim of this study was to investigate the effect of formaldehyde, β-propiolactone, hydrogen peroxide, ultraviolet rays, gamma irradiation and thermal inactivation on the immunogenic activity of inactivated vaccine preparations against HFRS Materials and methods. To achieve this aim, experimental vaccine preparations based on the PUU-TKD/VERO strain of Puumala virus were prepared and inactivated using the methods described above. The time intervals required for complete inactivation of the virus were determined, and the effects of the inactivators on viral RNA and immunogenic activity of the vaccine preparations were evaluated in BALB/c mouse and Syrian hamster models. Results. According to our results, vaccine preparations inactivated by different chemical and physical methods, which differ significantly in the mechanism of the mechanism of interaction with the virus, show no significant differences in immunogenic activity, except for thermal inactivation. Conclusion. A certain advantage of β-propiolactone is the short virus inactivation time, its complete degradation into non-toxic compounds within a few hours, and the reduction of total protein content after sterilization filtration, which is probably due to less aggregation of virus particles and cellular proteins

Inactivated vaccines are promising tools for tackling the COVID-19 pandemic. We applied several protocols for SARS-CoV-2 inactivation (by β-propiolactone, formaldehyde, and UV radiation) and examined the morphology of viral spikes, protein composition of the preparations, and their immunoreactivity in ELISA using two panels of sera collected from convalescents and people vaccinated by Sputnik V. Transmission electron microscopy (TEM) allowed us to distinguish wider flail-like spikes (supposedly the S-protein's pre-fusion conformation) from narrower needle-like ones (the post-fusion state). While the flails were present in all preparations studied, the needles were highly abundant in the β-propiolactone-inactivated samples only. Structural proteins S, N, and M of SARS-CoV-2 were detected via mass spectrometry. Formaldehyde and UV-inactivated samples demonstrated the highest affinity/immunoreactivity against the convalescent sera, while β-propiolactone (1:2000, 36 h) and UV-inactivated ones were more active against the sera of people vaccinated with Sputnik V. A higher concentration of β-propiolactone (1:1000, 2 h) led to a loss of antigenic affinity for both serum panels. Thus, although we did not analyze native SARS-CoV-2 for biosafety reasons, our comparative approach helped to exclude some destructive inactivation conditions and select suitable variants for future animal research. We believe that TEM is a valuable tool for inactivated COVID-19 vaccine quality control during the downstream manufacturing process. [ABSTRACT FROM AUTHOR]

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused huge social and economic distress. Given its rapid spread and the lack of specific treatment options, SARS-CoV-2 needs to be inactivated according to strict biosafety measures during laboratory diagnostics and vaccine development. The inactivation method for SARS-CoV-2 affects research related to the natural virus and its immune activity as an antigen in vaccines. In this study, we used size exclusion chromatography, western blotting, ELISA, an electron microscope, dynamic light scattering, circular dichroism, and surface plasmon resonance to evaluate the effects of four different chemical inactivation methods on the physical and biochemical characterization of SARS-CoV-2. Formaldehyde and β-propiolactone (BPL) treatment can completely inactivate the virus and have no significant effects on the morphology of the virus. None of the four tested inactivation methods affected the secondary structure of the virus, including the α-helix, antiparallel β-sheet, parallel β-sheet, β-turn, and random coil. However, formaldehyde and long-term BPL treatment (48 h) resulted in decreased viral S protein content and increased viral particle aggregation, respectively. The BPL treatment for 24 h can completely inactivate SARS-CoV-2 with the maximum retention of the morphology, physical properties, and the biochemical properties of the potential antigens of the virus. In summary, we have established a characterization system for the comprehensive evaluation of virus inactivation technology, which has important guiding significance for the development of vaccines against SARS-CoV-2 variants and research on natural SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Introduction: The rapid spread of coronavirus infection COVID-19 among the population of many countries around the world has contributed to the emergence of many genetic variants of SARS-CoV-2. Compared to previous coronavirus variants, the new Omicron variants have shown a noticeable degree of mutation. Virus inactivation is one of the most important steps in the development of inactivated vaccines. The chemical inactivation agents currently used are β-propiolactone and formaldehyde, but there is no uniform standard for designing and specifying the inactivation process., Objective: Evaluation and comparison of the effectiveness of chemical inactivation of two agents, formaldehyde and β-propiolactone against immunogenicity of the Omicron variant of the SARS-CoV-2 virus., Materials and Methods: Nasopharyngeal swabs were used to obtain the SARS-CoV-2 Omicron variant virus. Vero cell culture was used to isolate, reproduce, titrate the virus, and perform a neutralization reaction. The kinetics of studying the inactivation of the virus by chemical agents such as formaldehyde and β-propiolactone was carried out., Results: Studies have been conducted to comparatively evaluate the effectiveness of chemical agents used to inactivate the SARS-CoV-2 virus of the Omicron variant, planned for use in the production of an inactivated whole-virion vaccine. Formaldehyde and β-propiolactone were used as inactivation agents in concentrations of 0.05, 0.1, 0.5% of the total volume of the virus suspension. It has been established that complete inactivation of the virus by formaldehyde in the concentrations used at a temperature of 37 °C occurs within up to 2 hours, and when using beta-propiolactone, within up to 12 hours., Conclusion: Inactivated virus samples have different antigenic activity depending on the concentration of the inactivation agents used. The most pronounced antigenic activity is manifested in samples of the pathogen that were treated with an inactivation agent at a mild concentration of 0.05%. Increasing the concentration of inactivation agent by 5 or more times leads to a significant decrease in the antigenicity of the SARS-CoV-2 virus. With the inactivation modes used, the loss of biological activity of the virus occurs faster and antigenicity is retained largely when treated with formaldehyde.

Infectious pancreatic necrosis virus (IPNV), belonging to the genus Aquabirnavirus within the family Birnaviridae , causes huge economic loss to the global salmonid industry every year. Recently, outbreaks of disease caused by genogroup I IPNV were found in many rainbow trout (Oncorhynchus mykiss) farms worldwide. An inactivated vaccine was prepared using a genogroup I IPNV isolate with an optimized procedure as incubation with β-propanolactone (BPL) at the final concentration of 0.5% at room temperature for 48 h. The inactivated vaccine was used to immunize rainbow trout, and the protection efficiency was evaluated by viral loads determination, immune-related genes quantification, and neutralizing antibody tests. The viral loads in immunized rainbow trout were significantly decreased and the strongest antiviral effect was observed on 30 days post-immunization (d.p.i). The expression of innate immune-related genes IFN-1, and Mx-1 genes were significantly up-regulated on 3, 7, and 15 d.p.i (p < 0.05), and adaptive immune-related genes CD4, CD8, and IgM genes were significantly up-regulated on 15 and 30 d.p.i (p < 0.05). Neutralizing antibodies were firstly detected on 30 d.p.i and the highest titer was observed on 45 d.p.i, which began to decrease on 60 d.p.i, but was still significantly higher than that in negative control fish. The results indicated that the vaccine prepared in this study could stimulate the non-specific and specific immune response and provide significant immune protection to the vaccinated rainbow trout. • Genogroup I IPNV is causing huge economic loss to rainbow trout farming worldwide. • A promising inactivation scheme was established by using β-propanolactone (BPL). • An inactivated vaccine was prepared by using a genogroup I IPNV isolate. • The vaccine could provide immune protection to IPNV challenged rainbow trout. [ABSTRACT FROM AUTHOR]

Zwitterions have been attracting great attention and the synthesis of carboxylate-type zwitterions is complicated than those of sulfonate-type zwitterions. Therefore, we focused on one-step synthesis of carboxylate-type zwitterions with a lactone, reported in 1974. Since functional zwitterions as a category of ionic liquids are emerging materials, the characteristics and applications of the zwitterions were not studied. In this study, the one-step synthesis of carboxylate-type zwitterions was re-evaluated and characterize the biochemical and physico-chemical properties to explore potential and limitation of the synthesis. One-step synthesis of a carboxylate-type zwitterion was reproduced with sufficient purity. Although we found the emergence of a side product, which has not been reported in 1974, the side product was removed through successive hydrolysis. A liquid zwitterion, an emerging class of zwitterions, was also synthesized through the procedure. The one-step synthesis was confirmed to be useful and some characteristics of the synthesized zwitterions were similar to typical zwitterions. The synthesized zwitterion dissolved hardly-soluble cellulose with the aid of a co-solvent. On the other hand, the synthesized zwitterions have relatively low thermal stability and the low thermal stability suggests that the synthesized zwitterions have to be applied at mild temperatures, e.g. protein solvents and electrolytes. We here proposed the synthesized zwitterion as a cryoprotectant for mammalian cells as one of feasible applications. MDCK cells were well cryopreserved by the 10 wt% zwitterion aqueous solution.

The purpose of these studies was to optimize RHDV type 1 and 2 (RHDV1 and RHDV2) inactivation modes to use the obtained antigens in inactivated vaccines and diagnosticums. The inactivating effect of aminoethylethylenimine and β-propiolactone was studied in different concentrations in correlation with the exposure time and temperature. The correlation between the inactivating effect of the compound used and the accepted test conditions (concentration, temperature, and exposure time) was studied on a group of rabbits, each of which was injected intramuscularly with 1 cm3 of the inactivated material sample. At the end of the maximum exposure interval, a control sample of the viral material, kept under the same conditions without any inactivant added was similarly tested. Lethality was considered to evaluate the damaging action in the test and control groups: L = m/n, where m is the number of dead animals; n is the total number of rabbits in the group for testing of the inactivated material sample. The postmortem diagnosis was confirmed by testing the rabbit liver tissue homogenate for relative antigens using ELISA. It was found that aminoethylethylenimine and β-propiolactone did not have the same effect on the studied variants of the virus. In order to preserve at maximum the antigenic structures of the virus, the following inactivation modes were considered to be optimal: for RHDV1-aminoethylethylenimine at a concentration of 0.3% at 37 °C, exposure time – 72 hours, or β-propiolactone at a concentration of 0.1–0.3% at 25–37 °С, exposure time – 24–48 hours; for RHDV2 – aminoethylethylenimine at a concentration of 1% at 37 °C, exposure time – 72 hours, or β-propiolactone at a concentration 0.3% at 25 °С, exposure time – 24 hours.

[Display omitted] • BPL is a common chemical inactivating reagent used in vaccines. • Via BPL carcinogenicity, its residual should be hydrolyzed completely in vaccines to avoid cytotoxicity. • BPL residual determination in vaccines is challenging due to its low concentration, presence in a complex mixture of vaccine and lack of suitable chromophore. • BPL derivatization with RBH was used to enhance analytical sensitivity and stabilize the BPL molecule for measurement with HPLC-UV. β-propiolactone (BPL) is an alkylating agent used for inactivation of biological samples such as vaccines. Due to its known carcinogenic properties, complete hydrolysis of BPL is essential, and the detection of trace amounts is crucial. In this study a novel High-Performance Liquid Chromatography-Ultraviolet (HPLC-UV) method was developed. Rhodamine B hydrazide (RBH) was synthesized and utilized as a derivatizing reagent to react with BPL. The reaction was optimized in a weak acidic solution, resulting in a high yield. The separation of the RBH-derivatized BPL was achieved on a C8 column and detected by a UV detector at a wavelength of 560 nm. The method's validation demonstrated a high linearity (r2 > 0.99) over a concentration range of 0.5–50 µg/mL, with detection and quantification limits of 0.17 µg/mL and 0.5 µg/mL, respectively. The average recovery of samples was 85.20 % with a relative standard deviation (RSD) of 1.75 %. This method was successfully applied for BPL residue analysis in inactivated COVID-19 vaccines. This novel derivatization method offers a promising solution for monitoring BPL residues in the vaccine production process for quality control purposes and compliance with regulatory standards. [ABSTRACT FROM AUTHOR]

Transformations of β‐propiolactone in the binary superacidic systems HF/MF5 (M=Sb, As) were investigated at different temperatures. Salts of monoprotonated 3‐hydroxypropanoyl fluoride [H2O(CH2)2C(O)F][SbF6] (1) and [H2O(CH2)2C(O)F][AsF6] (2) were obtained by performing the reactions at temperatures lower than −40 °C. In contrast, temperatures higher than −40 °C yield the respective salts [C9H15O6][SbF6]3 (3) and [C9H15O6][AsF6]3 (4) containing a cyclic trication. The protonated species of β‐propiolactone was not observed. All salts were characterized by low temperature Raman and IR spectroscopy. In addition, single‐crystal X‐ray analyses were performed for (1) and (3). For both cations the existence of a cationic acyl species as a reactive intermediate in the form of [HO(CH2)2CO][MF6] is assumed. The formation of the acyl cation, based on protonated β‐propiolactone, was investigated by quantum chemical calculations on the MP2/aug‐cc‐pVTZ level of theory. [ABSTRACT FROM AUTHOR]

Abstract Background Transmissible gastroenteritis virus (TGEV) causes enteric infection in piglets, characterized by vomiting, severe diarrhea and dehydration, and the mortality in suckling piglets is often high up to 100%. Vaccination is an effective measure to control the disease caused by TGEV. Methods In this study, cell-cultured TGEV HN-2012 strain was inactivated by formaldehyde (FA), β-propiolactone (BPL) or binaryethylenimine (BEI), respectively. Then the inactivated TGEV vaccine was prepared with freund's adjuvant, and the immunization effects were evaluated in mice. The TGEV-specific IgG level was detected by ELISA. The positive rates of CD4+, CD8+, CD4+IFN-γ+, CD4+IL-4+ T lymphocytes were detected by flow cytometry assay. Lymphocyte proliferation assay and gross pathology and histopathology examination were also performed to assess the three different inactivating reagents in formulating TGEV vaccine. Results The results showed that the TGEV-specific IgG level in FA group (n = 17) was earlier and stronger, while the BEI group produced much longer-term IgG level. The lymphocyte proliferation test demonstrated that the BEI group had a stronger ability to induce spleen lymphocyte proliferation. The positive rates of CD4+ and CD8+ T lymphocyte subsets of peripheral blood lymphocyte in BEI group was higher than that in FA group and BPL groups by flow cytometry assay. The positive rate of CD4+IFN-γ+ T lymphocyte subset was the highest in the BPL group, and the positive rate of CD4+IL-4+ T lymphocyte subset was the highest in the FA group. There were no obvious pathological changes in the vaccinated mice and the control group after the macroscopic and histopathological examination. Conclusions These results indicated that all the three experimental groups could induce cellular and humoral immunity, and the FA group had the best humoral immunity effect, while the BEI group showed its excellent cellular immunity effect.

Inactivated vaccines are promising tools for tackling the COVID-19 pandemic. We applied several protocols for SARS-CoV-2 inactivation (by β-propiolactone, formaldehyde, and UV radiation) and examined the morphology of viral spikes, protein composition of the preparations, and their immunoreactivity in ELISA using two panels of sera collected from convalescents and people vaccinated by Sputnik V. Transmission electron microscopy (TEM) allowed us to distinguish wider flail-like spikes (supposedly the S-protein’s pre-fusion conformation) from narrower needle-like ones (the post-fusion state). While the flails were present in all preparations studied, the needles were highly abundant in the β-propiolactone-inactivated samples only. Structural proteins S, N, and M of SARS-CoV-2 were detected via mass spectrometry. Formaldehyde and UV-inactivated samples demonstrated the highest affinity/immunoreactivity against the convalescent sera, while β-propiolactone (1:2000, 36 h) and UV-inactivated ones were more active against the sera of people vaccinated with Sputnik V. A higher concentration of β-propiolactone (1:1000, 2 h) led to a loss of antigenic affinity for both serum panels. Thus, although we did not analyze native SARS-CoV-2 for biosafety reasons, our comparative approach helped to exclude some destructive inactivation conditions and select suitable variants for future animal research. We believe that TEM is a valuable tool for inactivated COVID-19 vaccine quality control during the downstream manufacturing process.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused huge social and economic distress. Given its rapid spread and the lack of specific treatment options, SARS-CoV-2 needs to be inactivated according to strict biosafety measures during laboratory diagnostics and vaccine development. The inactivation method for SARS-CoV-2 affects research related to the natural virus and its immune activity as an antigen in vaccines. In this study, we used size exclusion chromatography, western blotting, ELISA, an electron microscope, dynamic light scattering, circular dichroism, and surface plasmon resonance to evaluate the effects of four different chemical inactivation methods on the physical and biochemical characterization of SARS-CoV-2. Formaldehyde and β-propiolactone (BPL) treatment can completely inactivate the virus and have no significant effects on the morphology of the virus. None of the four tested inactivation methods affected the secondary structure of the virus, including the α-helix, antiparallel β-sheet, parallel β-sheet, β-turn, and random coil. However, formaldehyde and long-term BPL treatment (48 h) resulted in decreased viral S protein content and increased viral particle aggregation, respectively. The BPL treatment for 24 h can completely inactivate SARS-CoV-2 with the maximum retention of the morphology, physical properties, and the biochemical properties of the potential antigens of the virus. In summary, we have established a characterization system for the comprehensive evaluation of virus inactivation technology, which has important guiding significance for the development of vaccines against SARS-CoV-2 variants and research on natural SARS-CoV-2.

Hemorrhagic fever with renal syndrome (HFRS) is an acute zoonotic disease caused by the orthohantaviruses Puumala, Dobrava-Belgrad (four genotypes), Hantaan (genotype Amur), and Seoul. In the Russian Federation, HFRS occupies the leading place among all natural focal human diseases. Formaldehyde, β-propiolactone, and ultraviolet radiation were tested to select the optimal method for viral inactivation during the development of a whole-virion vaccine against HFRS. The specific activity and the immunogenicity of the vaccine were determined, respectively, by the number of copies of viral RNA per 1 mL and by the neutralizing antibodies in the blood sera of BALB/c mice in response to immunization. Analysis of the immunogenicity of vaccines inactivated with formaldehyde, β-propiolactone, or UV radiation did not find significant differences in the level of induced neutralizing antibodies. At the same time, β-propiolactone has obvious technological advantages as compared to formaldehyde and UV radiation: the time of viral inactivation is reduced by dozens of times; neutralization of the inactivator and control of its content in the final vaccine are not required; and the amount of inappropriate protein in the vaccine is decreased due to the decrease in protein aggregation. [ABSTRACT FROM AUTHOR]

The results of various methods of Puumala virus inactivation, including ultraviolet rays (UV), β -propiolactone (BPL) and formalin are presented. Immunogenicity of vaccine preparations obtained using these virus inactivation methods did not differ significantly in the experiments on BALB/c mice. Essential advantage of UV and BPL in relation to formaldehyde is the short time of virus inactivation.

Highlights • β-propiolactone (BPL) and formaldehyde (FA) were used to inactivate several influenza virus strains. • BPL abolished the infectivity, FA was unable to completely inactivate the virus. • All methods damaged the binding and fusion capacity; BPL caused greater loss than FA. • FA treatments caused the highest reduction in TLR-7 stimulation. • All the observed effects were strain-dependent. Abstract The vast majority of commercially available inactivated influenza vaccines are produced from egg-grown or cell-grown live influenza virus. The first step in the production process is virus inactivation with β-propiolactone (BPL) or formaldehyde (FA). Recommendations for production of inactivated vaccines merely define the maximal concentration for both reagents, leaving the optimization of the process to the manufacturers. We assessed the effect of inactivation with BPL and FA on 5 different influenza virus strains. The properties of the viral formulation, such as successful inactivation, preservation of hemagglutinin (HA) binding ability, fusion capacity and the potential to stimulate a Toll-like receptor 7 (TLR7) reporter cell line were then assessed and compared to the properties of the untreated virus. Inactivation with BPL resulted in undetectable infectivity levels, while FA-treated virus retained very low infectious titers. Hemagglutination and fusion ability were highly affected by those treatments that conferred higher inactivation, with BPL-treated virus binding and fusing at a lower degree compared to FA-inactivated samples. On the other hand, BPL-inactivated virus induced higher levels of activation of TLR7 than FA-inactivated virus. The alterations caused by BPL or FA treatments were virus strain dependent. This data shows that the inactivation procedures should be tailored on the virus strain, and that many other elements beside the concentration of the inactivating agent, such as incubation time and temperature, buffer and virus concentration, have to be defined to achieve a functional product. [ABSTRACT FROM AUTHOR]

Abstract A simple method was established for the determination of β -propiolactone (BPL) in human inactivated rabies vaccine by gas chromatography-mass spectrometry (GC-MS). The determination was performed on an Agilent HP-INNOWAX (30 m × 0.32 mm i.d., 0.25 µm) capillary column at the temperature of 80 °C. Electrospray ionization (ESI) was used by selective ion detection at m/z 42. The temperature for ESI source and inlet was set at 230 °C and 200 °C, respectively. Helium was used as the carrier gas at a flow rate of 25.1 mL/min. The total run time was 8 min. Acetonitrile and other components in the sample did not interfere with the determination of BPL. The results showed good linearity of BPL in the range of 0.50–10.01 μg/mL, with the limit of detection and the limit of quantification of 0.015 μg/mL and 0.050 μg/mL, respectively. Satisfactory precision was achieved for the current developed method. The method was applied to detect 6 batches of vaccine samples, and the results indicated that the target analyte BPL was present in three batches of unpurified samples, but was not detected in the purified samples, indicating the test samples were qualified. The established method was proved to be simple, versatile and sensitive, which can meet the requirements of quality control of BPL in human inactivated rabies vaccine. [ABSTRACT FROM AUTHOR]

Introduction: During the production process of vaccines against viral diseases, virus inactivation plays a crucial role. β-Propiolactone (BPL) is a compound that is frequently used for inactivation of viruses and production of the vaccines against viral diseases such as rabies. In this study, the effects of concentration of BPL as well as the duration and temperature of incubation with BPL on the infectivity of the rabies virus was investigated. Methods: Fixed rabies (Pasteur Virus) PV strain grown on BHK21C13 cell was treated with 1:3000, 1:4000 and 1:5000 final concentrations of BPL at 4°C, 21°C and 37°C and their effects were evaluated after 24, 48, 72 h and 5 days. Each sample was titrated after various intervals and tested for the viral infectivity in BSR cells. The BSR cells were infected by triple serial dilutions of the rabies virus PV strain, and then infectivity was detected by the fluorescent technique. Results: Entire loss of infectivity of the virus treated at 4°C with 1:3000 and 1:4000 of BPL was evident at the end of the 24 and 48 h incubation periods, respectively. Moreover, the loss of infectivity of the virus treated with all tested concentrations of BPL was evident at the end of the 72 h at 21°C and 4°C. Conclusion: These findings suggest that aside from BPL concentration, temperature plays the most important role on BPL inactivation. The inactivation effect could be observed at the end of 72 h incubation period; however, the best economic condition for rabies virus inactivation was shown to be 1:4000 at 4°C for 48 h.

Although the copolymerizations of L-lactide (LA) with seven- or six-membered ring lactones have been extensively studied, the copolymerizations of LA with four-membered ring lactones have scarcely been reported. In this work, we studied the copolymerization of LA with β-propiolactone (PL) and the properties of the obtained copolymers. The copolymerization of LA with PL was carried out using trifluoromethanesulfonic acid as a catalyst and methanol as an initiator to produce poly(LA-co-PL) with Mn of ~50,000 and PL-content of 6-67 mol %. The Tg values of the copolymers were rapidly lowered with increasing PL-contents. The Tm and ∆Hm of the copolymers gradually decreased with increasing PL-contents, indicating their decreased crystallinity. Biodegradation test of the copolymers in compost demonstrated their improved biodegradability in comparison with the homopolymer of LA. [ABSTRACT FROM AUTHOR]

The nucleoprotein components of plant viruses self-assemble into monodisperse, nanoscale structures with a high degree of symmetry and polyvalency. Of particular interest are the filamentous plant viruses which provide uniform high aspect ratio nanostructures-such structures remain challenging to obtain using purely synthetic approaches. Potato virus X (PVX) has drawn interest by the materials science community because of its filamentous structure measuring 515 × 13 nm; and both genetic engineering and chemical conjugation methods have been reported to impart new functionalities and develop PVX-based nanomaterials for applications in the health and materials sector. Toward environmentally safe materials-i.e., materials that are not infectious toward crops, such as potato, we reported methods to inactivate PVX. In this chapter, we describe the three methods to inactivate PVX and render it non-infectious toward plants, while maintaining structure and function., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Abstract: Vaccination is one of the best methods against viral diseases. In this study, experimental inactivated Singapore grouper iridovirus (SGIV) vaccines were prepared, and immunogenicity and protection against virus infection of the vaccines were investigated in orange-spotted grouper, Epinephelus coioides. Two kinds of vaccines, including β-propiolactone (BPL) inactivated virus at 4°C for 12h and formalin inactivated virus at 4°C for 12d, was highly protective against the challenge at 30-day post-vaccination and produced relative percent of survival rates of 91.7% and 100%, respectively. These effective vaccinations induced potent innate immune responses mediated by pro-inflammatory cytokines and type I interferon (IFN)-stimulated genes (ISGs). It is noteworthy that ISGs, such as Mx and ISG15, were up-regulated only in the effective vaccine groups, which suggested that type I IFN system may be the functional basis of early anti-viral immunity. Moreover, effective vaccination also significantly up-regulated of the expression of MHC class I gene and produced substantial amount of specific serum antibody at 4weeks post-vaccination. Taken together, our results clearly demonstrated that effective vaccination in grouper induced an early, nonspecific antiviral immunity, and later, a specific immune response involving both humoral and cell-mediated immunity. [Copyright &y& Elsevier]

Abstract: The far-infrared spectrum of β-propiolactone has been investigated in the region below 830cm−1 with a resolution of 0.000959cm−1 using synchrotron radiation from the Canadian Light Source. A detailed analysis of the observed rotational structure of the ν13 (490.955500(9)cm−1), ν20 (512.341950(10)cm−1) and ν19 (791.343000(10)cm−1) fundamental bands provides spectroscopic information for these low-lying vibrational modes which correspond to the Ce, Cplane and α-CH2 rock motions, respectively. The ground state spectroscopic parameters were accurately determined by fitting 1943 ground state combination differences from the observed rotational structure in the infrared region along with previously reported microwave transitions. The spectroscopic parameters for the excited states were subsequently determined by fitting a total of 9007 infrared transitions from the three newly assigned bands together with the previously reported transitions of the ν12 (747.244704(10)cm−1) and ν8 (1095.433607(14)cm−1) bands. The resulting global analysis of 13 311 infrared transitions provides an accurate determination of the excited state spectroscopic parameters of β-propiolactone including a first order a-type Coriolis interaction of the closely-spaced ν13 and ν20 bands. [Copyright &y& Elsevier]

Abstract: The irradiation of a free electron laser at Tokyo University of Science (FEL-TUS) to β-propiolactone molecules in the gas phase has efficiently induced the infrared multiple photon dissociation of the compound in the wavenumber regions of 1000–1100 and 1700–2000cm−1. The products were carbon dioxide and ethylene at equal amounts, where carbon dioxide was enriched with 13C under selected irradiation conditions. The relative yields of products and the selectivity of 13C were examined under various experimental conditions; the maximum 13C atom fraction of 59% was achieved when 2.5Torr β-propiolactone was irradiated by FEL pulses at 1750cm−1 with a fluence of 5.8Jcm−2. One of the reasons of this high selectivity is a large isotope shift of ∼47cm−1 for the h name="dbnd" />O stretching vibration around 1880cm−1, which is larger than the energy resolution of FEL-TUS. Another possible factor may be a shorter micropulse interval (∼350ps) of FEL-TUS than the collisional frequency of β-propiolactone molecules in the gas phase, which prevents the collisional energy transfer from 13C molecules to 12C molecules during successive micropulses. [ABSTRACT FROM AUTHOR]

Abstract: A computational study of the [2+2] cycloaddition reaction pathways for formaldehyde–ketene and formaldehyde–isocyanic acid has been presented by using the DFT(B3LYP) method. These cycloaddition reactions could yield to eight different four-membered molecules. In the two considered reactions, the reactions for the β-propiolactone and oxazetidinone products have the lower barriers of 26.40 and 32.88kcalmol−1 and are exothermic by 27.68 and 4.00kcalmol−1, respectively. The β-propiolactone and oxazetidinone ring compounds have been predicted to be the most stable thermodynamically. Simulation of the solvent environment (toluene, THF, acetone, acetonitrile and water) has been investigated by using polarized continuum model method, yet only small differences have been found to occur in energetics between the studied structures in the gas-phase and in the solvent. [Copyright &y& Elsevier]

Abstract: The pure rotational spectrum of β-propiolactone (c-C2H4COO) has been recorded between 7 and 21GHz using a pulsed jet Fourier transform microwave spectrometer. The resulting ground state spectroscopic constants guided the analysis of the rotationally-resolved infrared spectra of two bands that were collected using the far infrared beamline at the Canadian Light Source synchrotron. The observed modes correspond to motions best described as ring deformation (ν 12) at 747.2cm−1 and CO ring stretching (ν 8) at 1095.4cm−1. A global fit of 4430 a- and b-type transitions from the microwave spectrum and the two infrared bands provided an accurate set of ground state and excited state spectroscopic parameters. To complement the experimental results, the harmonic and anharmonic vibrational frequencies of all 21 infrared active modes of β-propiolactone have been calculated using the DFT B3LYP method (6-311+G(d,p), 6-311++G(2d,3p) basis sets). [Copyright &y& Elsevier]

[Display omitted] Here, we describe the synthesis and properties of BMeS- p -A-NHS as a sulfonylaniline-based fluorescent labeling reagent. Introduction of a carboxyl group into the amino group of the sulfonylaniline skeleton was achieved by the ring-opening reaction of β -propiolactone. This small labeling reagent was water-soluble, photostable, solid-state emissive, and suitable for excitation with a versatile 405-nm laser diode, emitting green fluorescence with a large Stokes shift at 527 nm. The succinimidyl ester reactive group facilitated conjugation with substrates containing amino groups. [ABSTRACT FROM AUTHOR]

-Propiolactone, Ring opening, Trication, IRC Calculations, Single-crystal X-ray analysis Front Cover: Ring Opening and Closure Reactions of -Propiolactone in the Superacids HF/MF5 (M=Sb, As) (Eur. J. Org. Keywords: -Propiolactone; Ring opening; Trication; IRC Calculations; Single-crystal X-ray analysis EN -Propiolactone Ring opening Trication IRC Calculations Single-crystal X-ray analysis 6626 6626 1 12/31/21 20211228 NES 211228 B The Front Cover b illustrates the reaction conditions of I i -propiolactone in the superacidic system HF/SbF SB 5 sb at low temperatures. [Extracted from the article]

Abstract: Frequencies of coincident genetic events were measured in strain D7 of Saccharomyces cerevisiae. This diploid strain permits the detection of mitotic gene conversion involving the trp5-12 and trp5-27 alleles, mitotic crossing-over and gene conversion leading to the expression of the ade2-40 and ade2-119 alleles as red and pink colonies, and reversion of the ilv1-92 allele. The three genes are on different chromosomes, and one might expect that coincident (simultaneous) genetic alterations at two loci would occur at frequencies predicted by those of the single alterations acting as independent events. Contrary to this expectation, we observed that ade2 recombinants induced by bleomycin, β-propiolactone, and ultraviolet radiation occur more frequently among trp5 convertants than among total colonies. This excess among trp5 recombinants indicates that double recombinants are more common than expected for independent events. No similar enrichment was found among Ilv+ revertants. The possibility of an artifact in which haploid yeasts that mimic mitotic recombinants are generated by a low frequency of cryptic meiosis has been excluded. Several hypotheses that can explain the elevated incidence of coincident mitotic recombination have been evaluated, but the cause remains uncertain. Most evidence suggests that the excess is ascribable to a subset of the population being in a recombination-prone state. [Copyright &y& Elsevier]

Summary: The efficacy and safety of two whole IgG polyvalent antivenoms (A and B) were compared in a randomised, blinded clinical trial in 67 patients systemically envenomed by Bothrops asper in Colombia. Both antivenoms were fractionated by caprylic acid precipitation and had similar neutralising potencies, protein concentrations and aggregate contents. Antivenom B was additionally treated with β-propiolactone to lower its anticomplementary activity. Analysing all treatment regimens together, there were no significant differences between the two antivenoms (A=34 patients; B=33 patients) in the time taken to reverse venom-induced bleeding and coagulopathy, to restore physiological fibrinogen concentrations and to clear serum venom antigenaemia. Blood coagulability was restored within 6–24h in 97% of patients, all of whom had normal coagulation and plasma fibrinogen levels 48h after the start of antivenom treatment. Two patients (3.0%) had recurrent coagulopathy and eight patients suffered recurrence of antigenaemia within 72h of treatment. None of the dosage regimens of either antivenom used guaranteed resolution of venom-induced coagulopathy within 6h, nor did they prevent recurrences. A further dose of antivenom at 6h also did not guarantee resolution of coagulopathy within 12–24h in all patients. The incidence of early adverse reactions (all mild) was similar for both antivenoms (15% and 24%; P >0.05). [Copyright &y& Elsevier]

A number of β-propiolactone homologue were synthesized and their bactericidal and fungicidal action studied. It was established that bactericidal action of β-propiolactones is connected with cleavage of the lactone ring by water hydrolysis, which leads to formation of a mobile hydrogen atom of the alcohol group of the respective β-oxy acids. Simultaneous introduction of two methyl radicals and a methyl group and an ethyl one to the β-position of propiolactone was shown to enhance bactericidal action of the appropriate homologue. A +l-inducible effect of the β-substituents of β-propiolactone hydrogen atoms on enhancement of bactericidal action is discussed as well as the influence of increasing hydrophobicity and branching of β-propiolactone homologue on the smoothing of bactericidal action. [Copyright &y& Elsevier]

Filamentous nanomaterials are flexible with a high aspect ratio, conferring unique mechanical, electromagnetic, and optical properties; promoting tissue penetration; and allowing the formation of hierarchical superstructures. The fabrication of synthetic nanofilaments with uniform properties is challenging, but this can be addressed by the use of filamentous plant viruses such as potato virus X (PVX), which are produced as monodisperse structures from a genetic template. To take advantage of PVX without risks to agriculture and the environment, it is necessary to inactivate the virus efficiently without disrupting its chemical and material properties. Herein, we report experiments showing that PVX can be completely inactivated by exposure to UV irradiation (0.5 J cm -2 ) or chemical treatment (1 mM β-propiolactone or 10 mM formalin) without interfering with the chemical addressability of lysine or cysteine residues, which are typically used as conjugation handles for virus nanoparticle functionalization.

Intravenous immunoglobulin (IVIg) preparations are widely used for anti-inflammatory therapy of autoimmune and systemic inflammatory diseases. Hyperimmunoglobulins enriched in neutralizing antibodies against viruses can, in addition to their virus-neutralizing activity, also exert immunomodulatory activity. Previously, we observed that Cytotect®, an anti-CMV hyperimmunoglobulin, was less effective in suppressing human T-cell responses in vitro compared to Hepatect® CP, an anti-HBV hyperimmunoglobulin. We hypothesized that the poor immunomodulatory activity of Cytotect® results from treatment with β-propiolactone during the manufacturing process. The manufacturer of these hyperimmunoglobulins has now introduced a new anti-CMV hyperimmunoglobulin, called Cytotect® CP, in which β-propiolactone treatment is omitted. Here we show that Cytotect® CP inhibits PHA-driven T-cell proliferation and cytokine production with similar efficacy as Hepatect® CP, whereas the former Cytotect® does not. In addition, Cytotect® CP inhibits allogeneic T-cell responses better than Cytotect®. Our results advocate the use of hyperimmunoglobulins that have not been exposed to β-propiolactone in order to benefit from their immunomodulatory properties. [ABSTRACT FROM AUTHOR]

Corona treatment of various substrates in nitrogen was found to markedly improve the adhesion between the substrate and polymeric coatings which were subsequently applied by in situ polymerization of the appropriate monomers. Sub strates included films, fibers, and fabrics of polymers such as polypropylene, polyethylene, polyelhylene terephthalate, polytetrafluoroethylene, and Saran. Condensation polymers employed as coatings included polyamides, polyesters, poly- sulfonamides, and poiyureas. Other polymer coatings were also applied by anionic and cationic polymerization. Com posites prepared after corona treatment of the substrate were shown to have superior interfacial adhesion and abrasion and solvent resistance, compared with composites which had been prepared without corona treatment. Electron micro copy was used to demonstiate the difference between differently treated samples of films and fabrics. The good interfacial adhesion exhibited by coatings on corona-treated films, even after extensive elongation of the composites, indicated the possibility of preparing bicomponent fibers from coated substrates which fibrillate on drawing. [ABSTRACT FROM PUBLISHER]

Purpose: One of the essential goals regarding the successful control of rabies infection is the development of a safe, effective, and inexpensive vaccine. the current study aimed to evaluate the inactivation potential of β-propiolactone (βPL), binary ethyleneimine (BEI), and hydrogen peroxide (H 2 O 2 )., Materials and Methods: Estimating the inactivation kinetics of βPL, BEI, and H 2 O 2 revealed that the tested inactivants could completely and irreversibly inactivate rabies virus within 2, 12, and 4 hours, respectively while maintaining its viral immunogenicity. The potency of βPL, BEI, and H 2 O 2 inactivated vaccines was higher than the World Health Organization acceptance limit and were in the order of 3.75, 4.21, and 3.64 IU/mL, respectively. Monitoring the humoral and cellular immunity elicited post-immunization using Staphylococcus aureus derived hyaluronic acid (HA) and bacillus Calmette-Guérin purified protein derivative (PPD) adjuvanted rabies vaccine candidates were carried out using enzyme-linked immunosorbent assay., Results: Results demonstrated that both adjuvants could progressively enhance the release of anti-rabies total immunoglobulin G as well as the pro-inflammatory mediators (interferon-gamma and interleukin-5) relative to time. However, a higher immune response was developed in the case of HA adjuvanted rabies vaccine compared to PPD adjuvanted one. The harmful consequences of the tested adjuvants were considered via investigating the histopathological changes in the tissues of the immunized rats using hematoxylin and eosin stain. Lower adverse effects were observed post-vaccination with HA and PPD adjuvanted vaccines compared to that detected following administration of the currently used alum as standard adjuvant., Conclusion: Our findings suggested that HA and PPD could serve as a promising platform for the development of newly adjuvanted rabies vaccines with elevated immune enhancing potentials and lower risk of health hazards., Competing Interests: No potential conflict of interest relevant to this article was reported., (© Korean Vaccine Society.)