Automated printing of microneedle patch COVID-19 mRNA vaccine

In a recent study published in nature biotechnologyresearchers reported automated printing of a microneedle patch (MNP) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger ribonucleic acid (mRNA) vaccine.

Background

Unvaccinated individuals in developing countries are at high risk of recurrent SARS-CoV-2 infection, causing unprecedented morbidity and mortality globally. Large-scale coronavirus disease 2019 (COVID-19) vaccination in community settings is hampered by inadequate cold chain logistics and a shortage of trained healthcare workers. Decentralized, local-level manufacturing of thermostable mRNA vaccines using the MNP format could provide a likely solution.

Intradermal (ID) delivered MNP is self-administrable, less painful than intramuscular (IM) delivery, produces no sharps waste, and is stable for months. Pfizer-BioNTech and Moderna, and a COVID-19 mRNA vaccine containing lipid nanoparticles (LNPs), effectively prevented the severe consequences of COVID-19.

About research

In the current study, researchers used microneedle vaccine printing (MVP) to produce a thermostable COVID-19 mRNA vaccine in an LNP vehicle.

Modular inks containing mRNA-loaded LNPs and dissolvable stabilizing polymer blends were used to fabricate MNPs by microneedle vaccine printing.Inks were optimized for high bioactivity by screening formulations in vitro Should be consistently unnecessary. Following automated dispensing, vacuum was applied through a polydimethylsiloxane (PDMS) mold to load the microneedles with the viscous vaccine-polymer solution.

The mold was then placed in a drying station for rapid drying. The team measured the loading time of several parameters related to MVP vaccine manufacturing and design. 147.0 nm diameter LNPs encapsulating the mRNA encoding firefly luciferase (fLuc) were mixed with various water-soluble polymers and dried.

A thermogravimetric analysis was performed to assess the drying time and the drying rates of different drying strategies were compared by linear regression modeling. Droplet area and MNP coverage of the polymer solutions were also evaluated. MNPs on ultrathin acrylic backings generated using a stand-alone device were imaged using scanning electron microscopy (SEM). Microneedle patch throughput was evaluated in terms of tray length and time required for drying.

The storage stability of the resulting MNPs was evaluated using model mRNA constructs. We evaluated the loading efficiency of single-step and double-step vaccines. We evaluated the efficiency of protein and deoxyribonucleic acid (DNA) loading in manually generated MNPs. Protein expression was measured in Henrietta Lacks (HeLa) cells after transfection with a resolubilized polymer that had protein expression similar to suspended LNP. Luminescence was observed after applying LNP containing cKK-E12 or lipid 5.0 to C57BL/6 mice for 6 hours.

The team compared administration of LNPs containing cKK-E12, which encodes the fLuc messenger ribonucleic acid, via the IM pathway, printed MNPs, and manually created MNPs. Additionally, mice were vaccinated with encapsulated mRNA encoding the SARS-CoV-2 spike (S) glycoprotein MNP-mediated receptor binding domain (RBD) followed by MNP boost after 4.0 weeks. Serum anti-SRBD immunoglobulin G (IgG) titers were measured using an electrochemiluminescent anti-SRBD binding assay.

result

MNP showed storage stability of more than 6.0 months at room temperature. Vaccine loading efficiency and MNP dissolution indicated that effective microgram-level doses of LNP-encapsulated mRNA can be administered by MNP. Inoculation of mice with SARS-CoV-2 spiked RBD stimulated durable immune responses comparable to those induced by intramuscular administration. SEM analysis showed images of her MNPs with conical and pyramidal shapes. The efficiencies of protein and DNA and protein loading in manually prepared MVP-made MNPs and MVP-made MNPs were comparable.

The heat map shows consistent DNA loading in microneedle patches across the 10.0 × 10.0 mold tray, with each square representing a different patch. Microneedles dissolved the mRNA-LNP vaccine and delivered it into the intradermal space. Pyramidal MNPs containing a 1:1 blend of polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) were stronger and stiffer than conical MNPs. Furthermore, 36.0% and 8.0% of the pyramidal and conical MNP volumes dissolved within 10 minutes, respectively, indicating that pyramidal MNPs enabled more vaccine delivery.

PVP:PVA stabilized mRNA-LNP in MNPs and achieved high protein expression after 6 months of storage at room temperature. The MNPs produced by MVP had suitable mechanical properties and successfully penetrated the porcine epidermis ex vivo. Testing of manually created MNPs live showed immune responses comparable to those induced by IM vaccination. Geometric mean titers (GMT) were similar for IM and MNP for the SARS-CoV-2 RBD mRNA vaccine after 3.0 weeks of boosting. Although anti-S RBD IgG titers for IM and MNP using SARS-CoV-2 RBD mRNA are similar, there are some differences between IM administration of mRNA-LNP suspension and ID delivery of mRNA-LNP using MNP. I saw some difference.

mRNA-LNP incorporating lipid 5.0 showed greater protein expression than cKK-E12, indicating MNP sensitivity to ionic lipids. Modeling data indicated that the mRNA-LNP SARS-CoV-2 vaccine could be formulated into 2.0 cm square MNPs for human application. The model predicted that 108 Pyramid MNPs and 360 MNPs could be fully dosed with Pfizer, Biontech and Moderna vaccines, respectively. Less than 20.0 minutes were required to load the increasing viscosity ink. The loading efficiency of LNPs was improved by using smaller MNPs, reducing the Marangoni effect and maximizing circularity. The 1st generation printer made him 100.0 patches in 2.0 days. The efficiency could be improved by continuously manufacturing MNPs by vertically stacking mold trays or degassing the trays prior to dispensing.

Conclusion

Overall, the study results show that LNP-encapsulated mRNA vaccines or other cargo-loaded soluble MNPs can be manufactured with microliter-scale precision through an automated manufacturing process, minimizing user manipulation of the MVP. emphasized development. Vaccines can be stored at room temperature and can be used months after manufacture, facilitating use in resource-limited settings and enabling cost-effective stockpiling of vaccines to prepare for future outbreaks. is improved.