SARS-CoV-2 variants and spike mutations involved in second wave of COVID-19 pandemic in India

Against the backdrop of the second wave of COVID-19 pandemic in India that started in March 2021, we have monitored the spike (S) protein mutations in all the reported (GISAID portal) whole-genome sequences of SARS-CoV-2 circulating in India from 1^st January 2021 to 31^st August 2021. In the 43,102 SARS-CoV-2 genomic sequences analysed, we have identified 24,260 amino acid mutations in the S protein, based on which 265 Pango lineages could be categorized. The dominant lineage in most of the 28 states of India and its 8 union territories was B.1.617.2 (the delta variant). However, the states Madhya Pradesh, Jammu & Kashmir, and Punjab had B.1.1.7 (alpha variant) as the major lineage, while the Himachal Pradesh state reported B.1.36 as the dominating lineage. A detailed analysis of various domains of S protein was carried out for detecting mutations having a prevalence of >1%; 70, 18, 7, 3, 9, 4, and 1 (N = 112) such mutations were observed in the N-terminal domain, receptor binding domain, C -terminal domain, fusion peptide region, heptapeptide repeat (HR)-1 domains, signal peptide domain, and transmembrane region, respectively. However, no mutations were recorded in the HR-2 and cytoplasmic domains of the S protein. Interestingly, 13.39% (N = 15) of these mutations were reported to increase the infectivity and pathogenicity of the virus; 2% (N = 3) were known to be vaccine breakthrough mutations, and 0.89% (N = 1) were known to escape neutralising antibodies. The biological significance of 82% (N = 92) of the reported mutations is yet unknown. As SARS-CoV-2 variants are emerging rapidly, it is critical to continuously monitor local viral mutations to understand national trends of virus circulation. This can tremendously help in designing better preventive regimens in the country, and avoid vaccine breakthrough infections. This article is protected by copyright. All rights reserved.

Evaluation of new rosin derivatives for pharmaceutical coating

Rosin and Rosin-based polymers have diversified drug delivery applications achieving sustained/controlled release profiles. In this manuscript, two new Rosin derivatives were synthesized and evaluated for physicochemical properties, molecular weight, polydispersity and glass transition temperature. Plasticizer-free films prepared by solvent evaporation were tested for surface morphology, water vapour transmission and mechanical properties (tensile strength, percent elongation and modulus of elasticity). The films showed low tensile strength and high percent elongation values achieving smooth and uniform surface. The derivatives were further characterized for film coating by evaluating the release of a model drug (diclofenac sodium) from pellets coated with the rosin derivatives as retarding membrane. Drug release was sustained up to 10 h due to 10% (w/w) coat built up with the new rosin derivatives. Increase in coat-built-up further facilitated sustained release from coated forms. Film coating could be achieved without agglomeration of the pellets within a reasonable operating time. The present study proposes novel film forming materials with potential use in sustained drug delivery.

Efficiency of Dispatch and Infiltrator cardiac infusion catheters in arterial localization of nanoparticles in a porcine coronary model of restenosis

Localized intramural delivery of sustained release biodegradable nanoparticles containing an antiproliferative agent could provide prolonged drug effect at the site of vascular injury that could inhibit the proliferation of smooth muscle cells and hence restenosis. The efficiency of arterial localization of nanoparticles is crucial in maximizing the drug effect in the target tissue. Therefore, the objective of the present study was to determine the comparative efficiency of the Dispatch and the Infiltrator cardiac infusion catheters to localize nanoparticles in the arterial wall. Following a standard balloon angioplasty procedure on the left anterior descending artery (LAD) in a porcine coronary model of restenosis, a suspension of nanoparticles containing a fluorescent marker was infused at the site of injury using either the Dispatch or the Infiltrator catheter. One hour following the infusion, animals were sacrificed and the nanoparticle levels in the LAD and other tissue were analyzed. The Dispatch catheter resulted in 3.3 folds greater efficiency of nanoparticle localization in the LAD than the Infiltrator catheter (309 +/- 124 vs. 93 +/- 43 microg/g of tissue, n = 6 for Dispatch and n = 5 for Infiltrator, p = 0.082, t-test). It is estimated that about 2% of the arterial volume can be displaced with the nanoparticle infusion. Fluorescence microscopy of the cross-sections of the LAD revealed greater fluorescence activity in the intimal layer with both the catheters, however the arteries infused using the Dispatch catheter demonstrated relatively higher degree of fluorescence activity in the medial and adventitial layers. The transmission electron microscopy of the arterial sections demonstrated infiltration of nanoparticles in the arterial wall and the histological analysis of the sections demonstrated no apparent damage to the endothelium due to the infusion of nanoparticles.