Stable Vaccine Research Articles

MRNA Vaccines: Unlocking Potential, Exploring Applications, and Envisioning Future Horizons.

In recent years, there have been notable strides in developing mRNA vaccines, resulting in the creation of potent immunizations against diverse diseases. This review examines the most recent advancements in this field, focusing on their implications for future vaccine development. The pursuit of heightened vaccine efficacy is investigated through cutting-edge methods in adjuvant selection, delivery system optimization, and antigen selection. The review also explores the potential for personalized vaccines based on genetic profiles, along with the latest techniques to ensure vaccine stability and extend shelf life. Highlighting the versatility of mRNA vaccines in addressing emerging infectious diseases and their variations, the review underscores the significance of swift response plans and advanced technologies to counter evolving viral mutations. In summary, this in-depth analysis emphasizes how mRNA vaccines hold transformative potential in reshaping both therapeutic and preventive strategies. Notable achievements include the creation of extremely potent mRNA vaccinations against the SARS-CoV-2 virus, resulting in the COVID-19 pandemic. Ongoing efforts to address challenges like long-term immune protection and increase the effectiveness and stability of mRNA vaccines are also discussed. This review's main goal is to provide a thorough summary of current advancements in mRNA vaccine technology while exploring how these advances may impact future approaches to treating and preventing different diseases.

A lyophilised formulation of chimpanzee adenovirus vector for long-term stability outside the deep-freeze cold chain

BackgroundThe adenovirus-vaccine platform has come to prominence with the COVID-19 vaccination campaigns. The objective of this study was to validate a formulation that was suitable for lyophilisation and long-term storage at 5 (2–8) °C.MethodsVaccine stability was assessed up to five years at 5 °C using a lyophilised formulation of the chimpanzee-adenovirus vector ChAd155 encoding a respiratory syncytial virus (RSV) antigen. Vaccine potency was assessed by functional infectivity assay. Other assessments of vaccine stability included those for capsid integrity, particle content, and DNA release. Vaccine efficacy and safety were assessed after two years in a murine model of RSV challenge and a rabbit toxicology model, respectively.ResultsHere, we show that the potency loss from lyophilisation was 0.12 log10. The potency loss over five years at 5 °C was estimated at 0.21 log10 (95%CI 0.10–0.30). This coincides with a 25% increase in the ratio of non-infectious particles/infectious particles. After two years of storage at 5 °C, (i) the loss of infectivity was 0.17 log10; (ii) the vaccine remained immunogenic and effective at clearing RSV from the lungs in a mouse-challenge model; and (iii) the vaccine was not associated with any adverse safety signal in a rabbit toxicology model.ConclusionsThe 5-year stability of the lyophilised adenovirus-vector vaccine is within our acceptable limit ( < 0.3 log10 decrease). Its formulation process is amenable to manufacturing scale-up and should help in providing adenovirus-based vaccines where the cold chain is problematic, such as in low-income countries, and in pre-epidemic stockpiling.

Elegant and Innovative Recoding Strategies for Advancing Vaccine Development.

Recoding strategies have emerged as a promising approach for developing safer and more effective vaccines by altering the genetic structure of microorganisms, such as viruses, without changing their proteins. This method enhances vaccine safety and efficacy while minimizing the risk of reversion to virulence. Recoding enhances the frequency of CpG dinucleotides, which in turn activates immune responses and ensures a strong attenuation of the pathogens. Recent advancements highlight synonymous recoding's potential, offering improved genetic stability and immunogenicity compared to traditional methods. Live vaccines attenuated using classical methods pose a risk of reversion to virulence and can be time-consuming to produce. Synonymous recoding, involving numerous codon alterations, boosts safety and vaccine stability. One challenge is balancing attenuation with yield; however, innovations like Zinc-finger antiviral protein (ZAP) knockout cell lines can enhance vaccine production. Beyond viral vaccines, recoding can apply to bacterial vaccines, as exemplified by modified Escherichia coli and Streptococcus pneumoniae strains, which show reduced virulence. Despite promising results, challenges like ensuring genetic stability, high yield, and regulatory approval remain. Briefly, ongoing research aims to harness these innovations for comprehensive improvements in vaccine design and deployment. In this commentary, we sought to further engage the community's interest in this elegant approach by briefly highlighting its main advantages, disadvantages, and future prospects.

Circular mRNA Vaccine against SARS-COV-2 Variants Enabled by Degradable Lipid Nanoparticles.

The emergence of mRNA vaccines offers great promise and a potent platform in combating various diseases, notably COVID-19. Nevertheless, challenges such as inherent instability and potential side effects of current delivery systems underscore the critical need for the advancement of stable, safe, and efficacious mRNA vaccines. In this study, a robust mRNA vaccine (cmRNA-1130) eliciting potent immune activation has been developed from a biodegradable lipid with eight ester bonds in the branched tail (AX4) and synthetic circular mRNA (cmRNA) encoding the trimeric Delta receptor binding domain of the SARS-CoV-2 spike protein. Notably, the cmRNA-1130 vaccine exhibits outstanding stability, remaining effective after six months of storage at 4 °C and multiple freeze-thaw cycles. In comparison with the commercial MC3 lipid, the nanoparticles formed from the degradable AX4 lipid revealed a much faster metabolic rate from the liver and spleen, affording negligible impairment to the hepatorenal function. Following intramuscular administration, cmRNA-1130 generates robust and sustained neutralizing antibodies and induces the activation of Delta RBD-specific CD4+ and CD8+ T effector memory cells (TEM) and Th1-biased T cells in mice. Featured with potent immune activation, high stability, and decent safety, vaccines formed from cmRNA and AX4 hold a huge clinical potential for the prophylaxis and treatment of different diseases.

MRNA Vaccines in Glioma: Antigen Selection, Immune Profiling, Comprehensive Strategies and Challenges

Glioma is one of the most invasive primary brain tumors, and the exploration of its treatment strategies has always been a focus in the field of neurooncology. In recent years, mRNA vaccine technology has shown great potential in the COVID-19 epidemic, and its application in the treatment of glioma has also attracted increasing attention. This article reviews the research progress of mRNA vaccines in the treatment of glioma, including the advantages and challenges of mRNA vaccines, the comparison of different RNA therapy methods, as well as the screening of tumor specific antigens, differentiation of immune subtypes, and development of comprehensive treatment strategies. Although mRNA vaccines have shown promising prospects in the treatment of gliomas, their clinical translation still faces challenges such as safety, production scale, and cost-effectiveness. The author believes that a deep understanding of the molecular mechanisms of glioma and the heterogeneity of the immune microenvironment is crucial for developing effective mRNA vaccines. Future research needs to make breakthroughs in improving the stability of mRNA vaccines, optimizing immunogenicity, developing personalized vaccines, and comprehensive treatment strategies.

Imaginations of Feasibility, Method of Production and Benefits of Oral MMR Vaccine

Measles, mumps and rubella are acute infectious diseases caused by viral infections in children and caused great harm before the use of vaccines. The Measles, Mumps and Rubella (MMR) oral vaccine indicates a breakthrough in the fight against three infectious diseases which are measles, mumps and rubella. Unlike the traditional injectable MMR vaccine. This oral vaccine does not require an injection, and it can improve patient acceptance. The purpose of this paper is to provide a comprehensive study of the development, efficacy and safety of the oral MMR vaccine and compare it with the traditional injectable vaccine. It will emphasize the benefits of oral vaccines, such as reduced needle-related fears and increased accessibility, which are particularly beneficial in resource-limited settings where needle vaccination may be impractical. In addition, this paper will discuss the challenges of maintaining vaccine stability, dosage accuracy, vaccine efficacy and safety. Through these analyses, this paper seeks to determine whether oral MMR vaccine can be a viable alternative to global immunization efforts.

Development and Evaluation of Five-in-One Vaccine Microneedle Array Patch for Diphtheria, Tetanus, Pertussis, Hepatitis B, and Haemophilus influenzae Type b: Immunological Efficacy and Long-Term Stability.

Background and objectives: The development of a five-in-one vaccine microneedle patch (five-in-one MN patch) aims to address challenges in administering vaccines against Diphtheria (DT), Tetanus (TT), Pertussis (wP), Hepatitis B (HBsAg), and Haemophilus influenzae type b (Hib). Combining multiple vaccines into a single patch offers a novel solution to improve vaccine accessibility, stability, and delivery efficiency, particularly in resource-limited settings. Methods: The five-in-one MN patch consists of four distinct microneedle arrays: DT and TT vaccines are coated together on one array, while wP, HepB, and Hib vaccines are coated separately on individual arrays. The patch was tested for long-term stability (12 months at 25 °C) and evaluated for immunogenicity in mice and minipigs. Antibody titers were measured using ELISA to compare immune responses between microneedle-based delivery and traditional intramuscular (IM) injection. Results: The five-in-one MN patch demonstrated stable antigenicity for up to 12 months at room temperature. In animal studies, the patch induced antibody titers comparable to traditional IM injections for all vaccines. Notably, immunogenic responses to Pertussis and Haemophilus influenzae type b vaccines via microneedles were reported for the first time. The patch facilitated the simultaneous yet independent delivery of vaccines, preserving their immunogenicity without interference. Conclusions: The five-in-one MN patch represents a significant advancement in vaccine delivery by enabling stable, minimally invasive, and efficient immunization. Its innovative design addresses the critical limitations of combination vaccines and has the potential to enhance vaccine accessibility in low- and middle-income countries. Future studies will focus on optimizing patch application techniques and evaluating broader clinical applicability.

Designing and comparative analysis of anti-oxidant and heat shock proteins based multi-epitopic filarial vaccines

BackgroundLymphatic Filariasis (LF) is a neglected tropical disease affecting more than 882 million people in 44 countries of the world. A multi-epitope prophylactic/therapeutic vaccination targeting filarial defense proteins would be invaluable to achieve the current LF elimination goal.MethodTwo groups of proteins, namely Anti-oxidant (AO) and Heat shock proteins (HSPs), have been implicated in the effective survival of the filarial parasites in their hosts. Several B-cell, CTL, and T-helper epitopes were predicted from the three anti-oxidant proteins GST, GPx, and SOD. Likewise, epitopes were also predicted for HSP110, HSP90, and HSP70. Among the predicted epitopes, screening was applied to include only non-allergenic, non-toxic epitopes to construct two MEVs, PVAO and PVHSP. The epitopes for each group of proteins were connected to each other by the inclusion of suitable linkers and an adjuvant. The 3D models for PVAO and PVHSP were predicted, and validated, followed by prediction of physicochemical properties using bioinformatics tools. The binding free energy of PVAO and PVHSP with Toll like Receptors (TLR) TLR1/2, TLR4, TLR5, TLR6, and TLR9 was calculated with HawkDock. The immunogenicity of both the MEVs were assessed by Immune simulation after which codon adaptation and in-silico cloning were carried out.ResultsConservation of the selected AOs and HSPs in other parasitic nematode species suggested that both the generated chimera could be helpful in cross-protection too. The 3D models of both MEVs contained more than 97% residues in allowed regions, as predicted by PROCHECK server. High MMGBSA and docking scores were obtained between MEVs and TLR4, TLR1/2, TLR6, and TLR9. Molecular dynamics simulation confirmed the stability of candidate vaccines in dynamic conditions present in the biological systems. The in-silico immune simulation indicated significantly high levels of IgG1, T-helper, T-cytotoxic cells, INF-γ, and IL-2 responses following immunization with PVAO and PVHSP.ConclusionThe immunoinformatics approaches used in this study confirmed that, the designed vaccines are capable of eliciting sustained immunity against LF, however, additional in-vivo studies would be required to confirm their efficacy. Furthermore, by employing multi-epitope structures and constructing two different cocktail vaccines for LF, this study can form an important milestone in the development of future LF vaccine/s.

Immunoinformatics approach: Developing a multi-epitope vaccine with novel carriers targeting monkeypox virus.

Since May 2022, the global spread of monkeypox virus (MPXV) has presented a significant threat to public health. Despite this, there are limited preventive measures available. In this study, different computational tools were employed to design a multi-epitope vaccine targeting MPXV. Three key MPXV proteins, M1R, B6R, and F3L, were chosen for epitope selection, guided by bioinformatic analyses to identify immunodominant epitopes for T- and B-cell activation. To enhance immune stimulation and facilitate targeted delivery of the vaccine to specific cells, the selected epitopes were linked to novel carriers, including the extracellular domain of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), a 12-mer Clec9a binding peptide (CBP-12), and a Toll-like receptor 2 (TLR2) peptide ligand. The designed vaccine construct exhibited strong antigenicity along with nonallergenic and nontoxic properties, with favorable physicochemical characteristics. The validated vaccine's tertiary structure underwent evaluation for interactions with CD80/86, Clec9a, and TLR2 through molecular docking and molecular dynamics simulation. The results ensured the vaccine's stability and high affinity for the aforementioned receptors. In silico immune simulations studies revealed robust innate and adaptive immune responses, including enhanced mucosal immunity essential for protection against MPXV. Ultimately, the DNA sequence of the vaccine construct was synthesized and successfully cloned into the pET-22b(+) vector. Our study, through integration of computational predictions, suggests the proposed vaccine's potential efficacy in safeguarding against MPXV; however, further invitro and invivo validations are imperative to assess real-world effectiveness and safety.

Double Deletion of EP402R and EP153R in the Attenuated Lv17/WB/Rie1 African Swine Fever Virus (ASFV) Enhances Safety, Provides DIVA Compatibility, and Confers Complete Protection Against a Genotype II Virulent Strain.

Background/Objectives: African swine fever virus (ASFV) is a devastating disease affecting domestic and wild suids and causing significant economic losses in the global pig industry. Attenuated modified live virus (MLV) vaccines are the most promising approaches for vaccine development. This study aimed to evaluate the safety and efficacy of four recombinant ASFV genotype II strains, derived from the non-hemadsorbing (non-HAD) attenuated isolate Lv17/WB/Rie1, through the single or simultaneous deletion of virulence-associated genes. Methods: Recombinant viruses were engineered by deleting the UK, EP402R, and EP153R genes, either individually or in combination. Four recombinant strains were evaluated for safety and efficacy in domestic pigs vaccinated intramuscularly with 102 TCID₅₀. Clinical signs, viremia, virus shedding, and antibody responses were monitored. Protection efficacy was assessed by challenging vaccinated pigs with the virulent genotype II Armenia07 strain. Additionally, a reversion-to-virulence study involving an overdose of the vaccine candidate was conducted to evaluate its stability through serial immunizations. Results: Deletion of the UK gene alone increased virulence, whereas the double deletion of EP402R and EP153R (Lv17/WB/Rie1-ΔCD) significantly enhanced safety while maintaining full protective efficacy. Vaccinated pigs exhibited reduced viremia, no virus shedding, and robust virus-specific antibody responses, achieving complete protection against Armenia07. The reversion-to-virulence study revealed potential but limited pathogenicity after multiple passages, indicating areas for improvement in vaccine stability. Conclusions: The Lv17/WB/Rie1-ΔCD strain demonstrates excellent safety and efficacy, along with potential DIVA (differentiating infected from vaccinated animals) compatibility, positioning it as a strong candidate for an ASFV MLV vaccine. Further research is needed to refine the vaccine and address the potential risks of reversion to virulence.

Safety and Immunogenicity of the Live Attenuated Vaccine QazCOVID-Live Against Coronavirus Infection COVID-19: Pre-Clinical Study Results.

The research conducted in this preclinical study assesses QazCovid-live, a live attenuated COVID-19 vaccine created in Kazakhstan, by conducting preclinical evaluations of safety, immunogenicity, and allergenicity in various animal models, including mice, rats, hamsters, and guinea pigs. The vaccine, developed by attenuating SARS-CoV-2 via numerous Vero cell passages, had no significant adverse effects in acute and subacute toxicity assessments, even at elevated dosages. Allergenicity testing indicated the absence of both immediate and delayed hypersensitivity reactions. Immunogenicity evaluations revealed strong virus-neutralizing antibody responses, especially following intranasal and intratracheal delivery. Studies on reversibility and transmission further validated the vaccine's stability and non-pathogenicity. The data indicate that QazCovid-live is safe, immunogenic, and prepared for clinical trials, presenting a potential strategy for COVID-19 prevention.

Development of a New Vaccine Adjuvant System Based on the Combination of the Synthetic TLR4 Agonist FP20 and a Synthetic QS-21 Variant.

In this study, we formulated an alternative to AS01b by combining FP20, a synthetic TLR4 agonist, and QS21v, a minimal saponin adjuvant, aiming to improve the vaccine efficacy and stability. The phase transition temperature of FP20 was determined by using differential scanning calorimetry to be 43.9 °C, providing a foundation for the formulation process. The coformulation was prepared using a dry film method for even adjuvant distribution. Characterization by dynamic light scattering and nanoparticle tracking analysis revealed a uniform particle size distribution of ∼120 nm. Cryogenic electron microscopy (CryoEM) revealed nanosized interactions between FP20 and QS21v, forming stable structures that likely enhanced the antigen presentation and immune activation. These physicochemical properties contributed to a robust in vivo synergy, where the coformulation elicited significantly higher antigen-specific antibody titers compared to individual adjuvants. These findings suggest that the FP20+QS21v coformulation provides a potent, stable, and safer alternative to traditional adjuvants, enhancing both vaccine efficacy and immunogenicity.

Advantages of Broad-Spectrum Influenza mRNA Vaccines and Their Impact on Pulmonary Influenza.

Influenza poses a significant global health challenge due to its rapid mutation and antigenic variability, which often leads to seasonal epidemics and frequent outbreaks. Traditional vaccines struggle to offer comprehensive protection because of mismatches with circulating viral strains. The development of a broad-spectrum vaccine is therefore crucial. This paper explores the potential of mRNA vaccine technology to address these challenges by providing a swift, adaptable, and broad protective response against evolving influenza strains. We detail the mechanisms of antigenic variation in influenza viruses and discuss the rapid design and production, enhanced immunogenicity, encoding of multiple antigens, and safety and stability of mRNA vaccines compared to traditional methods. By leveraging these advantages, mRNA vaccines represent a revolutionary approach in influenza prevention, potentially offering broad-spectrum protection and significantly improving global influenza management and response strategies.

A Novel Circular Delta-XBB15 RBD Dimeric Protein Subunit Vaccine Mediated by Split Intein Elicits an Immune Response and Protection Against Multiple SARS-CoV-2 Variants in Mice.

SARS-CoV-2 continues to mutate, leading to breakthrough infections. The development of new vaccine strategies to combat various strains is crucial. Protein cyclization can enhance thermal stability and may improve immunogenicity. Here, we designed a cyclic tandem dimeric receptor-binding domain protein (cirRBD2) via the split intein Cth-Ter. Cyclization does not affect the antigen epitopes of RBD but results in better thermal stability than that of its linear counterpart (linRBD2). Compared with the miceimmunized with linRBD2, those immunized with two doses of 5 μg of cirRBD2 produced significantly greater levels of broad-spectrum neutralizing antibodies, and generated a considerable cellular immune response. In the VEEV-VRP-hACE2-transduced mouse model, two doses of 5 μg of cirRBD2 provided protection against infection with BA.5, XBB.1.9, and partial protection against EG.5 which has more mutations. This study developed a novel circular RBD dimer subunit vaccine for SARS-CoV-2 that exhibits broad-spectrum neutralizing activity against various variants. A similar strategy can be applied to develop vaccines for other pathogens, especially for thermally stable vaccines.

Advancements in Nanoparticle-Based Adjuvants for Enhanced Tuberculosis Vaccination: A Review.

Tuberculosis (TB) remains a leading cause of morbidity and mortality worldwide, necessitating the development of more effective vaccines. Nanoparticle-based adjuvants represent a promising approach to enhancing tuberculosis vaccine efficacy. This review focuses on the advantages of nanoparticulate-loaded vaccines, emphasizing their ability to improve antigen delivery, safety, and immunogenicity. We discuss the various types of nanoparticles and their unique physicochemical properties that contribute to improved antigen delivery and sustained immune activation. Additionally, we highlight the advantages of nanoparticle-based adjuvants in inducing strong cellular and humoral immunity, enhancing vaccine stability, and reducing adverse effects. Finally, we address current challenges and future perspectives in the application of these novel adjuvants, emphasizing their potential to transform TB vaccine strategies and ultimately contribute to better global health outcomes.

Computer-aided rational design of a mRNA vaccine against Guanarito mammarenavirus.

Guanarito mammarenavirus (GTOV) is a highly pathogenic virus that leads to Venezuelan hemorrhagic fever (VHF). Despite being a severe disease, there are currently no commercially available drugs or vaccines for its prevention. Here we computationally formulated a mRNA vaccine construct (VC) from the genome of GTOV to produce immunity against its infections. Two proteins, namely zinc-finger motif protein (NP_899220.1), and nucleocapsid protein (NP_899211.1) were screened as potential candidates for downstream analysis. We determined the T and B cell epitopes of the candidate proteins. The resulting epitopes were analyzed, and the best epitopes were utilized in the formation of the peptide vaccine construct. The secondary and tertiary structures of the peptide construct were predicted and validated. Docking was conducted to check the binding energy of the designed peptide vaccine with the human immune receptors, namely TLR2 and TLR4. Our designed vaccine showed stable interactions with the HLA molecules, as verified through normal mode and MD simulation analysis. The immune simulation results indicated a positive immune response against the construct. A potentially stable mRNA vaccine was formulated by adding of sequences such as the Kozak, Goblin 5' UTR, tPA-signal peptide, MITD, 3' UTRs, and a poly(A) tail to the peptide vaccine construct. Lastly, the expression probability of the mRNA vaccine was confirmed in the expression system of E. coli strain K12. The designed vaccine showed the potential to elicit an immune response against the GTOV infection; however, experimental validation is recommended to verify the in-silico findings of this study.

The Effect of Mixed Lipid Concentrations and Sucrose on the Size of the Lipid Nanoparticles Containing mRNAs

The development of messenger RNA (mRNA) vaccines has been transformed using lipid nanoparticles (LNPs) as delivery systems. This study evaluates the impact of lipid mixture molar concentration and the addition of sucrose as a cryoprotectant on the size and stability of LNPs encapsulating mRNA. Using a microfluidic mixing technique, we formulated LNPs with varying lipid concentrations and analyzed their size, size distribution, and encapsulation efficiency through dynamic light scattering and a RiboGreen assay. Results indicated that higher lipid concentrations not only improved encapsulation efficiency but also maintained LNPs within the ideal size range of 80-120 nm, crucial for optimal biodistribution and immune cell uptake. Furthermore, the addition of sucrose significantly stabilized the LNPs against size changes during freeze-thaw cycles, particularly at lower temperatures. This study underscores the importance of optimizing lipid and sucrose concentrations to enhance the stability and functionality of LNPs, providing insights that could enhance the efficacy and storage stability of mRNA vaccines. HIGHLIGHTS The variation in molar concentrations of mixed lipids affects the particle size of LNP-mRNA. Buffer exchange using a membrane filter with centrifugation technique can reduce the size and uniformity of LNP particle distribution. The addition of sucrose affects the particle size of LNP-mRNA. The addition of 10 % sucrose as a cryoprotectant can maintain the particle size of LNP-mRNA at 4 and –20 °C. GRAPHICAL ABSTRACT

The Role of Freeze-Drying as a Multifunctional Process in Improving the Properties of Hydrogels for Medical Use.

Background/Objectives: Freeze-drying is a dehydration method that extends the shelf life and stability of drugs, vaccines, and biologics. Recently, its role has expanded beyond preservation to improve novel pharmaceuticals and their carriers, such as hydrogels, which are widely studied for both drug delivery and wound healing. The main aim of this study was to explore the multifunctional role of freeze-drying in improving the physicochemical properties of sodium alginate/poly(vinyl alcohol)-based hydrogels for medical applications. Methods: The base matrix and hydrogels containing a nanocarrier-drug system, were prepared by chemical cross-linking and then freeze-dried for 24 h at -53 °C under 0.2 mBa. Key analyses included determination of gel fraction, swelling ratio, FT-IR, SEM, TG/DTG, in vitro drug release and kinetics, and cytotoxicity assessment. Results: Freeze-drying caused an increase in the gel fraction of the hydrogel with the dual drug delivery system from 55 ± 1.6% to 72 ± 0.5%. Swelling ability was pH-dependent and remained in the same range (175-282%). Thermogravimetric analysis showed that freeze-dried hydrogels exhibited higher thermal stability than their non-freeze-dried equivalents. The temperature at 10% weight loss increased from 194.0 °C to 198.9 °C for the freeze-dried drug-loaded matrix, and from 188.4 °C to 203.1 °C for the freeze-dried drug-free matrix. The average pore size of the freeze-dried hydrogels was in the range of 1.07 µm ± 0.54 to 1.74 µm ± 0.92. In vitro drug release revealed that active substances were released in a controlled and prolonged way, according to the Korsmeyer-Peppas model. The cumulative amount of salicylic acid released at pH = 9.0 after 96 h was 63%, while that of fluocinolone acetonide reached 73%. Both hydrogels were non-toxic to human fibroblast cells, maintaining over 90% cell viability after 48 h of incubation. Conclusions: The results show a high potential for commercialisation of the obtained hydrogels as medical dressings.

Glycoside-Mediated Enhancement of Stability in Aluminum Oxyhydroxide Nanoadjuvants during Freeze-Drying.

Aluminum-based adjuvants have been indispensable to vaccine potency. However, their effectiveness is difficult to maintain after freeze-drying, which limits the storage and application of aluminum-adjuvanted vaccines. In this study, the impact of freeze-drying on aluminum oxyhydroxide nanorods (AlOOH NRs) was investigated. Freeze-drying led to aggregation and resulted in the loss of the surface hydroxyl content of aluminum adjuvants. To alleviate freeze-drying-induced damage, the potency of different alkyl glycosides as protectants was further evaluated. It was demonstrated that the structural balance of the head and tail of a glycoside was more conducive to protecting AlOOH NRs from aggregation and loss of surface hydroxyl groups. These results underline the proper selection of protectants to protect adjuvants against functional defects caused by freeze-drying, which is important for the stability and efficacy of vaccines and biopharmaceutical products.

Immune enhancement of rhamnolipid/manganese calcium phosphate mineralized nanoparticle: A promising subunit antigen delivery system

The use of biomimetic mineralization strategy is promising to solve the problem of poor stability and immune effect of subunit antigens. However, non-specifically inducing protein mineralization is still a challenge. we hypothesized that rhamnolipids with both protein and metal binding capacity could be used to develop more functional and biocompatible calcium mineralized nanoparticle (RMCP). The results show that rhamnolipids synergistically enhanced the mineralization of protein with manganese ions and improved 21 % the loading antigens of RMCP compared to manganese calcium phosphate nanoparticles. Transmission electron microscopy (TEM) and Dynamic Light Scattering (DLS) showed particle size of RMCP is 260 ± 12.1 nm with spherical morphology. In vitro experiments have shown that RMCP effectively activate immune cells through the cGAS-STING and NLRP3 pathways and demonstrated a higher level of cytokines in RAW264.7 Macrophages. In vivo, RMCP triggered an increased IgG titer with 16.5-fold IgG2a/IgG1 ratio compared to the aluminum adjuvant which improved the recovery status after challenge in mice. We used biological surfactants for the first time to enhance the biomimetic mineralization process of subunit antigen, which provides a new approach for constructing calcium-based biocompatible antigen delivery vectors, helping to develop a new generation of stable, efficient, and safe subunit vaccines.