Nanophytosome formulation of β-1,3-glucan and Euglena gracilis extract for drug delivery applications

Euglena gracilis (EG) is a unicellular freshwater alga known for its high β-1,3-glucan (BG) content with well-known biological properties and immune response. The high molecular weight structure of BG traditionally poses a challenge in terms of its size and absorption. Therefore, the aim of this study was to develop a novel drug delivery mechanism of BG and EG to nanophytosomes (NPs) by converting the heavy molecular weight of BG and EG into lipid phosphatidylcholine (PC), which plays an important role in improving their bioavailability and entrapment in captivity. The BG and EG NPs were developed by the solvent evaporation method while varying time and temperature to optimize their drug delivery ability. The size of BG-PC and EG-PC obtained by the Dynamic Light Scattering (DLS) method was 134.62 and 158.38 nm, respectively. Chemical (Fourier Transform Infra-Red) and structural (X-Ray Diffraction) characterization of NPs improved the binding capacity and the amorphous nature of both NPs. The shape of the NPs by Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) revealed their spherical, vesicular nature. The encapsulation efficiency of BG-PC and EG-PC was 82 ± 1.62 % and 87 ± 3.22 %, respectively, which improves the bioavailability. The developed methodology has thus proven effective in synthesizing BG-PC and EG-PC, which may be useful as NP drug delivery carriers. Future research could demonstrate the safety and effectiveness of long-term storage conditions for medical and pharmaceutical applications.•Nanophytosomes are tailored in size, shape and composition to optimize the delivery of phytochemicals/phytocompounds through nanoscale size and surface modification for better physiological absorption.•Nanophytosomes increase the stability of phytochemicals/phytocompounds and protect them from degradation due to heat or chemical reactions, leading to longer shelf life and improved therapeutic efficacy.•In this method, optimal conditions were created for the formation of β-1,3-glucan and Euglena gracilis extract nanophytosomes for successful development of drug delivery system that can effectively deliver bioactive compounds.

Mobile colistin resistance (mcr) genes and recent developments in colistin resistance detection

The peptide antibiotic colistin has been reserved as a last resort antibiotic treatment option for cases where other antibiotics including carbapenems have failed. Recent emergence of colistin resistance and discovery of mobile colistin resistance (mcr) genes, which encode the cell wall modifying phosphoethanolamine transferase enzyme, complicates the issue. The mcr genes have been associated with conjugative plasmids and can be horizontally transferred between different bacterial species. The global spread of mcr genes has been extensively documented and this warrants surveillance of the resistance genes in the community. However, susceptibility testing of colistin is fraught with practical challenges owing to the chemical nature of the drug and multiple mechanisms of resistance. Although broth microdilution is the current gold standard for colistin susceptibility testing, the method poses technical challenges. Hence, alternative detection methods for screening colistin resistance are the need of the hour. Several methods have been studied in the recent times to address this issue. In this review, we discuss some of the recent developments in the detection of colistin resistance.

Comparative evaluation of the efficacy of nicotine chewing gum and nicotine patches as nicotine replacement therapy using salivary cotinine levels as a biochemical validation measure

Background

Nicotine replacement therapy (NRT) and habit cessation counseling are considered the mainstay treatment for high nicotine dependence smokers. However, adherence to NRT is very poor. Among the NRTs, nicotine gums and nicotine patches are the most widely available. This study mainly evaluates the efficacy of nicotine gum and nicotine patches as NRT using salivary cotinine levels as a biochemical validation measure.

Materials and Methods

A cross-sectional study was conducted on 72 known smokers who were willing to receive nicotine replacement therapy for cessation of smoking habits. The sample was divided into two groups: Group 1 tobacco smokers were offered nicotine chewing gum, and group 2 tobacco smokers were offered nicotine patches. Both groups received treatment for 12 weeks. At baseline and at the end of the trial period, the saliva samples were analyzed for cotinine levels using an enzyme-linked immunosorbent assay (ELISA). The severity of smoking was assessed using the Fagerstrom Test for Nicotine Dependence (FTND).

Results

The quit rate was higher in the nicotine patch group compared with the nicotine gum group. On comparison of week one vs week twelve in the nicotine group nicotine gum group showed (CI: 18.10 to 13.83) and in the patch group (CI: 7.754 to 6.56) with P < 0.001. The pre- and post-cotinine estimation was significantly reduced for nicotine patches compared with nicotine gums, and patient compliance also yielded better results for nicotine patches.

Conclusion

This study depicts that nicotine patches were better adhered to in comparison with nicotine gums, and salivary cotinine level is an effective biochemical validation measure.

Association of haematological biomarkers with severity of COVID-19 pneumonia

Background:

Coronavirus disease 2019 (COVID-19) was first reported in Wuhan, China in December 2019. It is caused by SARS-CoV-2, a beta coronavirus. In this study, we assessed the association of biomarkers such as neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and lymphocyte monocyte ratio (LMR) with the severity of COVID-19 in patients.

Methods:

This retrospective observational study was carried out at a tertiary care hospital of the sub-Himalayan region of Uttarakhand over a period of six months from May to October 2020. A total of 350 patients with confirmed RT-PCR COVID-19 infection were included in the study. Detailed clinical, demographic and biochemical data of each patient was obtained from the hospital record section after permission from the Institute Ethical Committee. NLR, PLR and LMR ratios were calculated and compared with the outcomes in each patient. The patients were subdivided into two sub-groups: those with saturation less than 94% and those with saturation more than 94%. The patients were categorised as mild (with SpO₂ of > 94%) and moderate-severe (with SpO₂ of ≤94%) based on oxygen saturation.

Results:

A total of 350 patients with Covid-19 pneumonia were enrolled in the study. The mean age of the patients with oxygen saturation of ≤94% was 54.91 ± 13.29 years, which was comparable to the other group. Absolute neutrophil count (ANC) and NLR were significantly higher in patients with a saturation of < 94%. However, LMR and PLR were significantly lower in the group with saturation of <94%. Thus, a significant association was found between haematological inflammatory ratios and the severity of COVID-19 infection.

Conclusion:

NLR, LMR and PLR ratios can be utilised as point of care markers to assess severity in patients with COVID-19 pneumonia.

New brain perfusion imaging agents based on 99mTc-bis(aminoethanethiol) complexes: stereoisomers and biodistribution

In developing new brain perfusion imaging agents, we prepared 99mTc complexes of racemic mixtures of bis(aminoethanethiol) (BAT) derivatives containing an N'-benzylpiperazinyl (BPA) side chain. Due to the presence of a chiral center, a mixture of diastereomers (syn and anti) following chelation with the 99mTc (no-carrier-added) was obtained. The neutral and lipid-soluble 99mTc-BPA-BAT (99mTc, T1/2 = 6 h) isomers were separated. The syn and anti isomers of carrier-added 99Tc-BPA-BAT (99Tc, T1/2 = 2 x 10(5) years) were also synthesized, separated, and crystallized. The X-ray crystallography of 99Tc-BPA-BAT showed the syn and anti conformations (in relationship with the central TC(=O)N2S2 core). Despite a similarity in the partition coefficients for the two isomers, the syn isomer showed a higher in vivo brain uptake and longer brain retention in rats (2.77 and 1.08% dose/organ at 2 and 15 min) than that of the corresponding anti isomer (0.57 and 0.27% dose/organ at 2 and 15 min). This information is important and should be taken into consideration when new 99mTc-labeled brain perfusion imaging agents are being designed.

Synthesis, characterization and biodistribution of neutral and lipid-soluble 99mTc-PAT-HM and 99mTc-TMR for brain imaging

Two new ligand systems for complexation with 99mTc were prepared. The two analogs of bisaminoethanethiol (BAT): N,N'-bis(2-methyl-2-mercaptopropyl)-2,2-dimethylpropylenediamin e (PAT-HM) and N,N'-bis[2-(2-ethyl-1-mercaptopropyl)] ethylenediamine (TMR), form neutral and lipid soluble complexes with 99mTc that readily penetrate the blood-brain barrier following i.v. injection into rats. Although the 99mTc chelates do not display the prolonged brain retention required for use in single photon emission computed tomographic imaging studies, the fact that each ligand forms a neutral and lipid-soluble complex of high chemical stability when coordinated with 99mTc warrants further investigation to increase the site- and organ-specificity of these agents.

Angiotoxicity of oxygenated sterols and possible precursors

Cell death, inflammation, and repair in rabbits' aortas and pulmonary arteries were observed at 3-, 7-, and 10-day periods after the intravenous injection of oxygenated sterols. Thus, oxygenated sterols, not cholesterol, may play the primary role in arterial wall injury and lesion development.

Chemoimmunotherapy of cancer. 3. Analytical measurement of chemical half-lives of monofunctional alkylators

The objective of this study is the measurement of the rates of hydrolysis of a series of chloroethyl sulfide derivatives, under stimulated physiological conditions. Interferences encountered with the conventional spectrophotometric method prompted the use of a rapid-response, chloride selective electrode. This probe was readily capable of monitoring the hydrolytic rate, which is identical with the rate of chloride ion formation. Since the desired subsecond half-lives were not achieved by any of the compounds, factors influencing the rates were investigated. The results suggest that the rate-controlling cyclization step may be inhibited, due to coordination of undissociated protonic functional groups on the aromatic portions of the structures with the lone-pair electrons on sulfur.

Chemoimmunotherapy of cancer

The preparation of a series of water-soluble mustard haptens for chemoimmunotherapy of cancer is described. Preliminary screening data are given, indicating some activity against P388 lymphocytic leukemia for those compounds containing the most potent immunogenic functional groups.