A Newly Identified Spike Protein Targeted Linear B-Cell Epitope Based Dissolvable Microneedle Array Successfully Eliciting Neutralizing Activities against SARS-CoV-2 Wild-Type Strain in Mice

A Progesterone Microneedle Patch for Self-Administration in the Prevention of Preterm Birth in a Mouse Model

Background

Progesterone, recommended for preventing preterm birth (PTB) in high-risk women, is traditionally administered via oral capsules, vaginal gels, and oil injections, which pose issues like low bioavailability, systemic side effects, and irritation, leading to reduced compliance. To address these issues, a user-friendly administration approach to deliver progesterone was needed to development for the prevention of PTB.

Methods

We developed a progesterone microemulsion using ultra high-speed homogenization, optimizing formulation parameters and confirming stability. Subsequently, progesterone microemulsion-loaded microneedle (MN) patches were created, and its morphology, strength, and biocompatibility were assessed. The pharmacokinetics of these MN patches were then evaluated using LC/MS/MS. A mouse model was used to evaluate the therapeutic effects of the MN patch, with cell cytotoxicity, blood routine, and biochemistry tests assessing its biocompatibility.

Results

Benzyl benzoate and triglycerides were utilized as oil solvents, and Tween 80 served as the emulsifier in the preparation of a progesterone microemulsion. This formulation exhibited a particle size of 180.8 ± 20.5 nm, a zeta potential of -17.5 ± 3.4 mV, and a concentration of 20.59 ± 1.28 mg/mL. The particle size, zeta potential, and concentration of the sterilized microemulsion remained stable under 4°C. The prepared MN patch uses Povidone K30 and sucrose as excipients, which can maintain good hardness, intact needle shape, and constant drug concentration in the short term. The MN patch delivers progesterone with AUC and Cmax similar to oral progesterone microemulsion. In the preterm birth animal model, the median delivery days of mice in the progesterone microemulsion oral group and MN patch group were 19 and 20, respectively, and there was no statistical difference between the two groups. After using MN patches, the pores formed can quickly heal within 24 hours. After multiple uses of MN patches, significant abnormalities were not found in the blood routine, biochemical tests, and major organs of mice.

Conclusion

Microneedle patches loaded with progesterone microemulsion were successfully developed, efficiently delivering progesterone and reversing RU486-induced preterm birth in mice. The MN patch was user-friendly, minimally harmful to skin tissue, safe, and non-toxic, representing a promising new approach for the clinical treatment of premature labor.

Current Status of Microneedle Array Technology for Therapeutic Delivery: From Bench to Clinic

In recent years, microneedle (MN) patches have emerged as an alternative technology for transdermal delivery of various drugs, therapeutics proteins, and vaccines. Therefore, there is an urgent need to understand the status of MN-based therapeutics. The article aims to illustrate the current status of microneedle array technology for therapeutic delivery through a comprehensive review. However, the PubMed search was performed to understand the MN's therapeutics delivery status. At the same time, the search shows the number no of publications on MN is increasing (63). The search was performed with the keywords "Coated microneedle," "Hollow microneedle," "Dissolvable microneedle," and "Hydrogel microneedle," which also shows increasing trend. Similarly, the article highlighted the application of different microneedle arrays for treating different diseases. The article also illustrated the current status of different phases of MN-based therapeutics clinical trials. It discusses the delivery of different therapeutic molecules, such as drug molecule delivery, using microneedle array technology. The approach mainly discusses the delivery of different therapeutic molecules. The leading pharmaceutical companies that produce the microneedle array for therapeutic purposes have also been discussed. Finally, we discussed the limitations and future prospects of this technology.

Multi-epitopes vaccine design for surface glycoprotein against SARS-CoV-2 using immunoinformatic approach

Background

The recent COVID vaccinations have successfully reduced death and severity but did not stop the transmission of viruses by the emerging SARS-CoV-2 strain. There is a need for better and long-lasting dynamic vaccines for numerous prevailing strains and the evolving SARS-CoV-2 virus, necessitating the development of broad-spectrum strains being used to stop infection by reducing the spread rate and re-infection. The spike (S) glycoprotein is one of the proteins expressed commonly in the early phases of SARS-CoV-2 infection. It has been identified as the most immunogenic protein of SARS-CoV-2.

Methods

In this study, advanced bioinformatics techniques have been exploited to design the novel multi-epitope vaccine using conserved S protein portions from widespread strains of SARS-CoV-2 to predict B cell and T cell epitopes. These epitopes were selected based on toxicity, antigenicity score and immunogenicity. Epitope combinations were used to construct the maximum potent multi-epitope construct with potential immunogenic features. EAAAK, AAY, and GPGPG were used as linkers to construct epitopes.

Results

The developed vaccine has shown positive results. After the chimeric vaccine construct was cloned into the PET28a (+) vector for expression screening in Escherichia coli, the potential expression of the construct was identified.

Conclusion

The construct vaccine performed well in computer-based immune response simulation and covered a variety of allelic populations. These computational results are more helpful for further analysis of our contract vaccine, which can finally help control and prevent SARS-CoV-2 infections worldwide.

A Newly Identified Spike Protein Targeted Linear B-Cell Epitope Based Dissolvable Microneedle Array Successfully Eliciting Neutralizing Activities against SARS-CoV-2 Wild-Type Strain in Mice

Vaccination is a cost-effective medical intervention. Inactivated whole virusor large protein fragments-based severe acute respiratory syndrome coronavirus (SARS-CoV-2) vaccines have high unnecessary antigenic load to induce allergenicity and/orreactogenicity, which can be avoided by peptide vaccines of short peptide fragments that may induce highly targeted immune response. However, epitope identification and peptide delivery remain the major obstacles in developing peptide vaccines. Here, a multi-source data integrated linear B-cell epitope screening strategy is presented and a linear B-cell epitope enriched hotspot region is identified in Spike protein, from which a monomeric peptide vaccine (Epitope25) is developed and applied to subcutaneously immunize wildtype BALB/c mice. Indirect ELISA assay reveals specific and dose-dependent binding between Epitope25 and serum IgG antibodies from immunized mice. The neutralizing activity of sera from vaccinated mice is validated by pseudo and live SARS-CoV-2 wild-type strain neutralization assays. Then a dissolvable microneedle array (DMNA) is developed to pain-freely deliver Epitope25. Compared with intramuscular injection, DMNA and subcutaneous injection elicit neutralizing activities against SARS-CoV-2 wild-type strain as demonstrated by live SARS-CoV-2 virus neutralization assay. No obvious damages are found in major organs of immunized mice. This study may lay the foundation for developing linear B-cell epitope-based vaccines against SARS-CoV-2.