A microneedle vaccine printer for thermostable COVID-19 mRNA vaccines.

Decentralized manufacture of thermostable mRNA vaccines in a microneedle patch (MNP) format could enhance vaccine access in low-resource communities by eliminating the need for a cold chain and trained healthcare personnel. Here we describe an automated process for printing MNP Coronavirus Disease 2019 (COVID-19) mRNA vaccines in a standalone device. The vaccine ink is composed of lipid nanoparticles loaded with mRNA and a dissolvable polymer blend that was optimized for high bioactivity by screening formulations in vitro. We demonstrate that the resulting MNPs are shelf stable for at least 6 months at room temperature when assessed using a model mRNA construct. Vaccine loading efficiency and microneedle dissolution suggest that efficacious, microgram-scale doses of mRNA encapsulated in lipid nanoparticles could be delivered with a single patch. Immunizations in mice using manually produced MNPs with mRNA encoding severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein receptor-binding domain stimulate long-term immune responses similar to those of intramuscular administration.

A Machine Learning-optimized system for on demand, pulsatile, photo- and chemo-therapeutic treatment using near-infrared responsive MoS 2 -based microparticles in a breast cancer model.

Cancer therapy research is of high interest because of the persistence and mortality of the disease and the side effects of traditional therapeutic methods, while often multimodal treatments are necessary based on the patient's needs. The development of less invasive modalities for recurring treatment cycles is thus of critical significance. Herein, a light-activatable microparticle system was developed for localized, pulsatile delivery of anticancer drugs with simultaneous thermal ablation, by applying controlled ON-OFF thermal cycles using near-infrared laser irradiation. The system is composed of poly(caprolactone) microparticles of 200 µm size with incorporated molybdenum disulfide (MoS 2 ) nanosheets as the photothermal agent and hydrophilic doxorubicin or hydrophobic violacein, as model drugs. Upon irradiation the nanosheets heat up to ≥50 °C leading to polymer matrix melting and release of the drug. MoS 2 nanosheets exhibit high photothermal conversion efficiency and allow for application of low power laser irradiation for the system activation. A Machine Learning algorithm was applied to acquire optimal laser operation conditions; 0.4 W/cm 2 laser power at 808 nm, 3-cycle irradiation, for 3 cumulative minutes. In a mouse subcutaneous model of 4T1 triple-negative breast cancer, 25 microparticles were intratumorally administered and after 3-cycle laser treatment the system conferred synergistic phototherapeutic and chemotherapeutic effect. Our on-demand, pulsatile synergistic treatment resulted in increased median survival up to 40 days post start of treatment compared to untreated mice, with complete eradication of the tumors at the primary site. Such a system could have potential for patients in need of recurring cycles of treatment on subcutaneous tumors.

ADCC enhancement: A conundrum or a boon to mAb therapy?

The ability of antibodies to distinctly identify the antigens is an important feature exploited by the scientific community for the treatment of various diseases. The therapeutic action of monoclonal antibodies (mAbs) is mediated along with the cells of the immune system, such as natural killer cells, T cells and macrophages. The two major mechanisms that govern the therapeutic efficacy of mAbs are the antibody dependent cell mediated cytotoxicity (ADCC) and the complement dependent cytotoxicity (CDC). Consequently, much of the research dedicated to improving their action is focussed on enhancing either of these mechanisms. This manuscript focuses on the strategies to enhance ADCC, for providing more efficacious mAb therapeutics. These approaches essentially bring about changes in the elements of ADCC mechanism, such as the effector cell or the antibody itself and thus favour an enhanced therapeutic response. Several technologies of ADCC enhancement have been developed, based on the success of various strategies advanced by the researchers. These technologies show success with a few antibody therapeutics while they do not work with others. This review presents a detailed overview on these strategies and presents perspectives regarding the same.

Engineering a folic acid-decorated ultrasmall gemcitabine nanocarrier for breast cancer therapy: Dual targeting of tumor cells and tumor-associated macrophages.

Combination of passive targeting with active targeting is a promising approach to improve the therapeutic efficacy of nanotherapy. However, most reported polymeric systems have sizes above 100 nm, which limits effective extravasation into tumors that are poorly vascularized and have dense stroma. This will, in turn, limit the overall effectiveness of the subsequent uptake by tumor cells via active targeting. In this study, we combined the passive targeting via ultra-small-sized gemcitabine (GEM)-based nanoparticles (NPs) with the active targeting provided by folic acid (FA) conjugation for enhanced dual targeted delivery to tumor cells and tumor-associated macrophages (TAMs). We developed an FA-modified prodrug carrier based on GEM (PGEM) to load doxorubicin (DOX), for co-delivery of GEM and DOX to tumors. The co-delivery system showed small particle size of ∼10 nm in diameter. The ligand-free and FA-targeted micelles showed comparable drug loading efficiency and a sustained DOX release profile. The FA-conjugated micelles effectively increased DOX uptake in cultured KB cancer cells that express a high level of folate receptor (FR), but no obvious increase was observed in 4T1.2 breast cancer cells that have a low-level expression of FR. Interestingly, in vivo, systemic delivery of FA-PGEM/DOX led to enhanced accumulation of the NPs in tumor and drastic reduction of tumor growth in a murine 4T1.2 breast cancer model. Mechanistic study showed that 4T1.2 tumor grown in mice expressed a significantly higher level of FOLR2, which was selectively expressed on TAMs. Thus, targeting of TAM may also contribute to the improved in vivo targeted delivery and therapeutic efficacy.

Co-delivery of 2-Deoxyglucose and a glutamine metabolism inhibitor V9302 via a prodrug micellar formulation for synergistic targeting of metabolism in cancer.

The unique metabolic demand of cancer cells suggests a new therapeutic strategy targeting the metabolism in cancers. V9302 is a recently reported inhibitor of ASCT2 amino acid transporter which shows promising antitumor activity by blocking glutamine uptake. However, its poor solubility in aqueous solutions and tumor cells' compensatory metabolic shift to glucose metabolism may limit the antitumor efficacy of V9302. 2-Deoxyglucose (2-DG), a derivative of glucose, has been developed as a potential antitumor agent through inhibiting glycolysis in tumor cells. In order to achieve enhanced antitumor effect by inhibiting both metabolic pathways, a 2-DG prodrug-based micellar carrier poly-(oligo ethylene glycol)-co-poly(4-((4-oxo-4-((4-vinylbenzyl)oxy)butyl)disulfaneyl)butanoic acid)-(2-deoxyglucose) (POEG-p-2DG) was developed. POEG-p-2DG well retained the pharmacological activity of 2-DG in vitro and in vivo, More importantly, POEG-p-2DG could self-assemble to form micelles that were capable of loading V9302 to achieve co-delivery of 2-DG and V9302. V9302-loaded POEG-p2DG micelles were small in sizes (~10 nm), showed a slow kinetics of drug release and demonstrated targeted delivery to tumor. In addition, V9302 loaded POEG-p-2DG micelles exhibited improved anti-tumor efficacy both in vitro and in vivo. Interestingly, 2-DG treatment further decreased the glutamine uptake when combined with V9302, likely due to inhibition of ASCT2 glycosylation. These results suggest that POEG-p2DG prodrug micelles may serve as a dual functional carrier for V9302 to achieve synergistic targeting of metabolism in cancers. STATEMENT OF SIGNIFICANCE: Unique cancer cell's metabolism profile denotes a new therapeutic strategy. V9302 is a recently reported glutamine metabolism inhibitor that shows promising antitumor activity. However, its poor waster solubility and tumor cell's compensatory metabolic network may limit its potential clinical application. 2-Deoxyglucose(2-DG) is a widely used glycolysis inhibitor. However, its clinical application is hindered by low efficacy as monotherapy. Thus, in this study, we developed a redox-sensitive, 2-DG-based prodrug polymer, as a dual-functional carrier for co-delivery of V9302 and 2-DG as a combination strategy. V9302 loaded POEG-p-2DG micelle showed significantly improved antitumor activity through synergistic targeting of both glutamine and glycolysis metabolism pathway. More interestingly, POEG-p-2DG itself further facilitates inhibition of glutamine metabolism, likely through inhibition of ASCT2 glycosylation.