Hybrid Lipid Nanocapsules: A Robust Platform for mRNA Delivery

The success of the mRNA vaccine against COVID-19 has garnered significant interest in the development of mRNA therapeutics against other diseases, but there remains a strong need for a stable and versatile delivery platform for these therapeutics. In this study, we report on a family of robust hybrid lipid nanocapsules (hLNCs) for the delivery of mRNA. The hLNCs are composed of kolliphore HS15, labrafac lipophile WL1349, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and a conjugate of oleic acid (OA) and polyethylenimines of varying size (PEI─0.8, 1.8, and 25 kDa). They are prepared by a solvent-free, temperature-phase inversion method, yielding an average size of ∼40 nm and a particle distribution index (PDI) < 0.2. We demonstrate that the PDI remains <0.2 over a wide pH range and in a wide range of medium. We further show that the PDI and the functionality of mRNA condensed on the particles are robust to drying in a sugar glass and subsequent rehydration. Finally, we demonstrate that mRNA-loaded hLNCs yield reasonable transfection in vitro and in vivo settings.

Purification and characterization of laccase secreted by Phellinus linteus MTCC-1175 and its role in the selective oxidation of aromatic methyl group

A laccase from the culture filtrate of Phellinus linteus MTCC-1175 has been purified to homogeneity. The method involved concentration of the culture filtrate by ammonium sulphate precipitation and an anion exchange chro- matography on DEAE-cellulose. The SDS-PAGE and native-PAGE gave single protein band indicating that the enzyme preparation was pure. The molecular mass of the enzyme determined from SDS-PAGE analysis was 70 kDa. Using 2,6-dimethoxyphenol, 2,2'[azino-bis-(3-ethylbonzthiazoline-6-sulphonic acid) diammonium salt] (ABTS) and 4-hydroxy-3,5-dimethoxybenzaldehyde azine as the substrates, the Kin, kcat and kt/Km values of the laccase were found to be 160 microM, 6.85 s(-1), 4.28 x 10(4) M(-1) s(-1), 42 microM, 6.85 s(-1), 16.3 x 10(4) M(-1) s(-1) and 92 microM, 6.85 s(-1), 7.44 x 10(4) M(-1) s(-1), respectively. The pH and the temperature optima of the P. linteus MTCC-1175 laccase were 5.0 and 45 degrees C, respectively. The activation energy for thermal denaturation of the enzyme was 38.20 kJ/mole/K. The enzyme was the most stable at pH 5.0 after 1 h reaction. In the presence ofABTS as the mediator, the enzyme transformed toluene, 3-nitrotoluene and 4-chlorotoluene to benzaldehyde, 3-nitroben-zaldehyde and 4-chlorobenzaldehyde, respectively.

Purification, characterisation and coal depolymerisation activity of lignin peroxidase from Lenzitus betulina MTCC-1183

Lignin peroxidase from the culture filtrate of Lenzitus betulina MTCC-1183 has been purified to homogeneity using concentration by ultrafiltration and anion exchange chromatography on DEAE cellulose. The molecular weight of the purified lignin peroxidase using SDS-PAGE analysis was 43 kDa. Specific activity of the enzyme was 29.58 IU/mg. The K(m) values for veratryl alcohol and H2O2 for the purified enzyme were 54 microM and 81 microM, respectively. The k(cat) value of the purified enzyme was 2.3 s(-1) using 3,4-dimethoxybenzyl alcohol as the substrate. The optimal conditions for the lignin peroxidase assay were detected at pH 2.4 and 22 degrees C. Thermal stability of the purified enzyme has also been studied and its activation energy for deactivation was 287 kJ/mol. The purified lignin peroxidase depolymerised humic acid in presence of H2O2. Depolymerisation of coal by the L. betulina MTCC-1183 has been demonstrated using humic acid as a model of coal.