• July 14, 2024

Delivery Strategies for mRNA Vaccines

The therapeutic potential for messenger RNA (mRNA) in infectious diseases and cancer was first realized almost three decades ago, but only in 2018 did the first lipid nanoparticle-based small interfering RNA (siRNA) therapy reach the market with the United States Food and Drug Administration (FDA) approval of patisiran (Onpattro) for hereditary ATTR amyloidosis. This was largely made possible by major advances in the formulation technology for stabilized lipid-based nanoparticles (LNPs). Design of the cationic ionizable lipids, which are a key component of the LNP formulations, with an acid dissociation constant (pKa) close to the early endosomal pH, would not only ensure effective encapsulation of mRNA into the stabilized lipoplexes within the LNPs, but also its subsequent endosomal release into the cytoplasm after endocytosis. Unlike other gene therapy modalities, which require nuclear delivery, the site of action for exogenous mRNA vaccines is the cytosol where they get translated into antigenic proteins and thereby elicit an immune response. LNPs also protect the mRNA against enzymatic degradation by the omnipresent ribonucleases (RNases). Cationic nano emulsion (CNE) is also explored as an alternative and relatively thermostable mRNA vaccine delivery vehicle. In this review, we have summarized the various delivery strategies explored for more details joplink Recombinant Human Serine  mRNA vaccines, including naked mRNA injection; ex vivo loading of dendritic cells; CNE; cationic peptides; cationic polymers, and finally the clinically successful COVID-19 LNP vaccines  (Pfizer/BioNTech and Moderna vaccines)-their components, design principles, formulation parameter optimization, and stabilization challenges. Despite the clinical success of LNP-mRNA vaccine formulations, there is a specific need to enhance their storage stability above 0 °C for these lifesaving vaccines to reach the developing.

Understanding the role of microperimetry in glaucoma

The present narrative review attempts to provide an overview on the use of microperimetry or fundus-driven perimetry in glaucoma, considering the clinical use, the different strategies and limits compared to standard automated perimetry.  An electronic database (PubMed and Medline) search was performed of articles of any type published in the English language between 1998 and 2020 with a combination of the following terms: microperimetry, glaucoma, primary open-angle chronic glaucoma, visual field, Humphrey visual field, fundus automated perimetry. All the original articles, case reports, and short series analyzed were included in the present review, offering an excursus on the strengths and limitations characterizing the use of microperimetry in glaucomatous patients. The characteristics of a recently introduced fundus-driven perimetry Compass (CMP; Centervue, Padua, Italy) were also included. Although there remain several contradictions regarding routine use of microperimetry and the restricted research on this topic limits our ability to draw firm conclusions, microperimetry may be preferable in cases of localized retinal nerve fiber layer defects in patients with primary open-angle glaucoma and normal visual field. However, standard automated perimetry remains the gold standard for monitoring glaucoma, especially in patients with diffuse retinal nerve fiber layer impairment and visual field defects. The newly introduced Compass device can potentially provide a more accurate structural-functional evaluation than standard automated perimetry and can therefore produce superior testing reliability.


Ligand-Directed GPCR Antibody Discovery

Developing affinity reagents recognizing and modulating G-protein coupled receptors (GPCR) function by traditional animal immunization or in vitro screening methods is challenging. Some anti-GPCR antibodies exist on the market, but the success rate of development is still poor compared with antibodies targeting soluble or peripherally anchored proteins.

  • More importantly, most of these antibodies do not modulate GPCR function. The current pipeline for antibody development primarily screens for overall affinity rather than functional epitope recognition. We developed a new strategy utilizing natural ligand affinity to generate a library of antibody variants with an inherent bias toward the active site of the GPCR.
  • Instead of using phage libraries displaying antibodies with random CDR sequences at polymorphism sites observed in natural immune repertoire sequences, we generated focused antibody libraries with a natural ligand encoded within or conjugated to one of the CDRs or the N-terminus.
  • To tailor antibody binding to the active site, we limited the sequence randomization of the antibody in regions holstering the ligand while leaving the ligand-carrying part unaltered in the first round of randomization. With hits from the successful first round, the second round of randomization of the ligand-carrying part was then performed to eliminate the bias of the ligand.
  • Based on our results on three different GPCR targets, the proposed pipeline will enable the rapid generation of functional antibodies (both agonists and antagonists) against high-value targets with poor function epitope exposures including GPCR, channels, transporters as well as cell surface targets whose binding site is heavily masked by glycosylation.

endohedral trihedral metallo-borospherenes with spherical aromaticity

It is well-known that transition-metal-doping induces dramatic changes in the structures and bonding of small boron clusters, as demonstrated by the newly observed perfect inverse sandwich D8h [La(η8-B8)La] and D9h [La(η9-B9)La]. Based on extensive global minimum searches and first-principles theory calculations, we predict herein the possibility of perfect endohedral trihedral metallo-borospherene D3h La@[La5&B30] (1, 3A’1) and its monoanion C La@[La5&B30] (2, 2A’) and dianion D3h La@[La5&B30]2- (3, 1A’1). read more

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