A comparative study on chitosan nanoparticle synthesis methodologies for application in aquaculture through toxicity studies

Abstract Chitosan nanoparticles (CSNPs) have been recently used for various applications in aquaculture, especially as drug carriers. The aim of this study was to synthesise and investigate a superlative method of CSNP synthesis for application in aquaculture through aquaculture‐based toxicology screening methods. Two different methods were analysed: the first a direct ionic gelation method (A) and the other involving a low‐molecular‐weight chitosan microparticle intermediate method (B). Dynamic light scattering characterisation revealed that the CSNP particle sizes were 192.7 ± 11.8 and 22.9 nm from methods A and B, respectively. The LC50 values for brine shrimp toxicity were found to be 1.51 and 0.02 ppt in 24 h for methods A and B, respectively. Acute toxicity studies in Litopenaeus vannamei rendered LC50 values of 3235.94 and 2884.03 ppt in 24 h for methods A and B, respectively. Zebrafish toxicity studies revealed mortality rates of 21.67% and 55% at 20 mg/L concentration for methods A and B, respectively, with an increased expression of intracellular reactive oxygen species in method B. From these findings, it can be concluded that a comparatively reduced toxicity of CSNPs derived from ionic gelation method makes it more appropriate for application in aquaculture

Modulation by insulin rather than blood glucose of the pain threshold in acute physiological and flavone induced antinociception in mice

1009-1016<span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">The present study investigated the cause effect relationship between glycemic and algesic states. The hypo- and hyperglycemic conditions were induced physiologically through exercise (3 min swim at room temperature 28°-30°C) and external dextrose (2 g/kg, ip) administration respectively in mice. Besides, flavone (50 mg/kg, sc) a known antinociceptive drug was chosen to study such a cause effect relationship. The anti-nociception was assessed by acetic acid assay, blood glucose measured using glucometer (Ames) and serum insulin by radioimmunoassay. The findings revealed that irrespective of the glycemic state whether hypo-, hyper, or euglycemic induced by swim stress, dextrose or flavone <span style="font-size:15.5pt;mso-bidi-font-size:8.5pt;font-family: " times="" new="" roman","serif""="">per se <span style="font-size:15.0pt; mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">respectively, significant antinociceptive response was recorded. Pretreatment with flavone (50 mglkg, sc) always exhibited a tendency to reverse the hyperglycemia, if any, but enhanced the antinociceptive response either after swim stress or after dextrose. These data support the contention that changes in the glycemic state in acute condition is not responsible for antinociceptive response and thereby suggesting dissociation between these two parameters. Extended studies estimating serum insulin level after the above mentioned maneuvers showed a significant rise whenever antinociceptive response was recorded irrespective of the glycemic state. <span style="font-size:15.5pt;mso-bidi-font-size: 8.5pt;font-family:" arial","sans-serif""="">It <span style="font-size:15.0pt; mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">is suggested that serum insulin level, a hormonal parameter rather than the blood glucose level, which is a metabolic parameter, appears more reliable. It appears that the changes in serum insulin level produced by various treatments may have a relationship with the antinociceptive response. However, this study has the limitation that the results can apply only for acute conditions and extrapolation to clinical conditions is debatable. </span

Antinociceptive pattern of flavone and its mechanism as tested by formalin assay

182-185Flavone, dextrose and long swim stress exhibited antinociception. Degree of antinociception was greater with long swim stress as compared to flavone or dextrose. Combination of these treatments resulted in potentiation of antinociception. Naloxone (opioid antagonist; 5 mg/kg ip) antagonised flavone or long stress induced antinociception showing opioid mediated mechanism, however, failed to reverse the potentiated antinociceptive component recorded in long stressed animals which received flavone and dextrose. Antinociceptive activity of flavone, dextrose and long swim stress which was documented by acetic acid assay has been confirmed in the present study. Role for opioid system in this action has been demonstrated. Therefore, formalin test can also be considered as an useful assay procedure for testing flavonoids. However, like acetic acid assay this assay procedure also has the limitation that it is unable to detect minor changes in the degree of antinociception produced by physiological interventions such as long swim and dextrose

Characterization of Changes due to pH Variations in Beta Peptide ((25-35)) Leading to Alzheimer's Disease

Rajendran, Thirugnanasambandam/0000-0001-8158-9133; Rajendran, Thirugnanasambandam/0000-0001-8158-9133;WOS: 000498986900001The effect of various concentrations of amyloid beta peptide (ABP) in different pH (pH 2, 6, 7, 8, 10) in aging at different time intervals was analysed using various techniques. the pH 7.4 and 8 were compared with other pH solution which indicated that the secondary structure content with high beta-sheet conformation is found at pH 7.4 and 8. Phosphate buffer solutions (pH) were detected using CD spectroscopy. the CD spectra of peptide in phosphate buffer (pH 2 and 10) on aging at time intervals were also analysed with the aging of sample (pH 2) on the 10th day. the results showed no major secondary structural changes in the peptide, which was indicative predominant random coil structure. the phosphate buffer pH 6, 7.4, 8 on the 10th day showed the occurrence of crossover point. This same sample smear on slide was mounded and the fibrils were visualized using the light microscope. the percent of viable cell in different pH was detected in MTT (3-(4,5-Dimethyazol-2-yl)-2, 5-diphenyl-tetrazolium bromide) assay using human keratinocyte cell line (HaCaT). Fluorescence spectroscopy was used to study the growth and development of fibrils

Evaluation of the Toxic Effect of <i>Bauhinia purpurea</i> Mediated Synthesized Silver Nanoparticles against <i>In-vitro</i> and <i>In-vivo</i> Models

Metal nanoparticles, such as gold nanoparticles, silver nanoparticles, etc., have many benefits and have been in use for a very long time. Nevertheless, a number of concerns have been raised about the environmental impact and the possibility of exposure to various living systems at the moment. Thus, in this study, silver nanoparticles were synthesized by using plant gum from Bauhinia purpurea and characterization was done using UV—Visible Spectroscopy, Scanning Electron Microscopy, X—ray Diffraction, etc. To determine the accumulation and toxic effects caused by the nanoparticles, Eudrilus eugeniae, Danio rerio, and their embryos were exposed to the synthesized silver nanoparticles and evaluated using microscopic observation, histology, and Inductively Coupled Plasma Optical Emission Spectrometry (ICP—OES)

Evaluation of Heavy Metal Removal of Nanoparticles Based Adsorbent Using <i>Danio rerio</i> as Model

Nanoparticles are potential candidates for wastewater treatment especially for the removal of heavy metals due to their strong affinity. Many biopolymers are used as adsorbents and encapsulation of nanoparticle onto them can increase their efficiency. In this study, SPIONs, alginate, and SPIONs incorporated on alginate beads have been synthesized and characterized both microscopically and spectroscopically. These were then used for the removal of chromium metal and the percentage of removal was evaluated using a batch adsorption study. The percent removal of chromium using SPIONs, alginate and alginate–SPIONs beads were recorded to be 93%, 91% and 94%, respectively. The adsorption of chromium using SPIONs and alginate–SPIONs beads followed the Tempkin isotherm, whereas adsorption of chromium metal by alginate beads was found to be homogeneous in nature and followed the Langmuir isotherm with an R2 value of 0.9784. An in-vivo study using Danio rerio as a model organism was done to examine the toxicity and the removal efficiency of the samples. It was observed that chromium water treated with alginate–SPIONs beads, which were removed after water treatment showed less damage to the fishes when compared to SPIONs and alginate beads treated with chromium water where the SPIONs and alginate beads were not removed after the treatment period