Gentamicin Released from Porous Scaffolds Fabricated by Stereolithography

Porous oligolactide-hydroxyapatite composite scaffolds were obtained by stereolithographic fabrication. Gentamicin was then coated on the scaffolds afterwards, to achieve antimicrobial delivery ability to treat bone infection. The scaffolds examined by stereomicroscope, SEM, and μCT-scan showed a well-ordered pore structure with uniform pore distribution and pore interconnectivity. The physical and mechanical properties of the scaffolds were investigated. It was shown that not only porosity but also scaffold structure played a critical role in governing the strength of scaffolds. A good scaffold design could create proper orientation of pores in a way to strengthen the scaffold structure. The drug delivery profile of the porous scaffolds was also analyzed using microbiological assay. The release rates of gentamicin from the scaffolds showed prolonged drug release at the levels higher than the minimum inhibitory concentrations for S. aureus and E. coli over a 2-week period. It indicated a potential of the scaffolds to serve as local antibiotic delivery to prevent bacterial infection

In vitro studies on gastrointestinal monogastric and avian models to evaluate the binding efficacy of mycotoxin adsorbents by liquid chromatography-tandem mass spectrometry

Objective: The objective of this study is evaluating the efficacies of 11 mycotoxin adsorbent products, marketed in South East Asia. Three prominently occurring mycotoxins; aflatoxin B1 (AFB1), deoxynivalenol (DON), and zearalenone (ZEN) were simultaneously spiked into the samples. Materials and Methods: Samples were simultaneously tested in vitro in phosphate buffer and simulated at different pH conditions in the gastrointestinal tracts of the porcine and avian model, analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results: All mycotoxin adsorbent products had high efficacy at over 90% for AFB1 adsorption in both GI porcine and avian models. AFB1 could be adsorbed more in acidic condition than the basic condition. ZEN adsorption was determined to be more stable at pH 3 than pH 6.5 or 8.4, in which pH condition might influence on ZEN desorption rate. DON was poorly adsorbed by all tested agents. Conclusions: The finding showed that the adsorption rate varied depending on the type of adsorbent. Our results might provide useful information regarding the efficacy of mycotoxin adsorbents commercially marketed in the region. [J Adv Vet Anim Res 2019; 6(1.000): 125-132

A New Benzaldehyde Derivative Exhibits Antiaflatoxigenic Activity against <i>Aspergillus flavus</i>

Aflatoxin B1 (AFB1) is the most potent naturally occurring carcinogen for humans and animals produced by the common fungus Aspergillus flavus (A. flavus). Aflatoxin (AF) contamination in commodities is a global concern related to the safety of food and feed, and it also impacts the agricultural economy. In this study, we investigated the AFB1-inhibiting activity of a new benzaldehyde derivative, 2-[(2-methylpyridin-3-yl)oxy]benzaldehyde (MPOBA), on A. flavus. It was found that MPOBA inhibited the production of AFB1 by A. flavus, with an IC50 value of 0.55 mM. Moreover, the inhibition of conidiation was also observed at the same concentration. The addition of MPOBA resulted in decreased transcript levels of the aflR gene, which encodes a key regulatory protein for the biosynthesis of AF, and also decreased transcript levels of the global regulator genes veA and laeA. These results suggested that MPOBA has an effect on the regulatory mechanism of the development and differentiation of conidia, leading to the inhibition of AFB1 production. In addition, the cytotoxicity study showed that MPOBA had a very low cytotoxic effect on the Madin-Darby canine kidney (MDCK) cell line. Therefore, MPOBA may be a potential compound for developing practically effective agents to control AF contamination

Enrofloxacin and its major metabolite ciprofloxacin in green sea turtles (Chelonia mydas): An explorative pharmacokinetic study

The present study aimed to assess the pharmacokinetic features of enrofloxacin (ENR) and its major metabolite, ciprofloxacin (CIP) in green sea turtles (Chelonia mydas) after single intravenous (i.v.) and intramuscular (i.m.) administration at two dosages of 5 and 7.5&nbsp;mg/kg body weight (b.w.). The study used 10 animals randomly divided into equal groups. Blood samples were collected at assigned times up to 168&nbsp;hr. The concentrations of ENR and CIP in turtle plasma were quantified by a validated high-performance liquid chromatography equipped with fluorescence detector (HPLC-FLD). The concentration of ENR in the experimental turtles with respect to time was pharmacokinetically analyzed using a noncompartment model. The concentrations of ENR in the plasma were quantified up to 144&nbsp;hr after i.v. and i.m. administrations at dosages of 5 and 7.5&nbsp;mg/kg b.w., whereas CIP was quantified up to 96 and 144&nbsp;hr, respectively. The elimination half-life values of ENR were 38.7 and 50.4&nbsp;hr at dose rates of 5 and 7.5&nbsp;mg/kg b.w. after i.v. administration, whereas CIP was 33.6 and 22.6&nbsp;hr, respectively. The maximum concentration (Cmax) values of ENR were 2.07 and 2.59&nbsp;μg/ml at dose rates of 5 and 7.5&nbsp;mg/kg b.w., respectively. The value of area under the curve from 0 to 24&nbsp;hr (AUC0–24)/minimum inhibitory concentration (MIC) ratio of ENR was &gt;125 for bacteria with MIC of 0.12 and 0.13&nbsp;μg/ml after the administration of 5&nbsp;mg/kg by i.m. and i.v. administration, respectively. Based on the pharmacokinetic data, susceptibility break-point and pharmacokinetic (PK)/pharmacodynamic (PD) indices, i.m. single administration of ENR at a dosage of 5&nbsp;mg/kg b.w. might be clinically appropriate for treatment of susceptible bacteria in green sea turtles (Chelonia mydas)