The ever-increasing incidence of drug-resistant
infections has invigorated the focus on the discovery and development of novel treatment options. The discovery and investigation of essential ...mycobacterial targets is of utmost importance. In addition to the discovery of novel targets, focusing on non-lethal pathways and the use of host-directed therapies has gained interest. These adjunctive treatment options could not only lead to increased antibiotic susceptibility of
, but also have the potential to avoid the emergence of drug resistance. Host-directed therapies, on the other hand, can also reduce the associated lung pathology and improve disease outcome. This review will provide an outline of recent opportunities.
During normal pregnancy, placental oxidative stress (OS) is present during all three trimesters and is necessary to obtain normal cell function. However, if OS reaches a certain level, pregnancy ...complications might arise. In preeclampsia (PE), a dangerous pregnancy specific hypertensive disorder, OS induced in the ischemic placenta causes a systemic inflammatory response and activates maternal endothelial cells. In this study, we aimed to quantify superoxide concentrations (as a measure of systemic OS) using electron paramagnetic resonance (EPR) and correlate them to markers of systemic inflammation, iron status and vascular function.
Fifty-nine women with a healthy pregnancy (HP), 10 non-pregnant controls (NP) and 28 PE patients (32±3.3weeks) were included. During HP, blood samples for superoxide, neutrophil to lymphocyte ratio (NLR), mean platelet volume (MPV) and iron status were taken at 10, 25 and 39 weeks. Vascular measurements for arterial stiffness (carotid-femoral pulse wave velocity (CF-PWV), augmentation index (AIx), augmentation Pressure (AP)) and microvascular endothelial function (reactive hyperemia index (RHI)) were performed at 35 weeks. In PE, all measurements were performed at diagnosis. CMH (1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine) was used as spin probe for EPR, since the formed CM radical corresponds to the amount of superoxide.
Superoxide concentration remains stable during pregnancy (p = 0.92), but is significantly higher compared to the NP controls (p<0.0001). At 25 weeks, there is a significant positive correlation between superoxide and ferritin concentration. (p = 0.04) In PE, superoxide, systemic inflammation and iron status are much higher compared to HP (all p<0.001). During HP, superoxide concentrations correlate significantly with arterial stiffness (all p<0.04), while in PE superoxide is significantly correlated to microvascular endothelial function (p = 0.03).
During HP there is an increased but stable oxidative environment, which is correlated to ferritin concentration. If superoxide levels increase, there is an augmentation in arterial stiffness. In PE pregnancies, systemic inflammation and superoxide concentrations are higher and result in a deterioration of endothelial function. Together, these findings support the hypothesis that vascular function is directly linked to the amount of OS and that measurement of OS in combination with vascular function tests might be used in the prediction of PE.
Natural products, either as pure compounds or as standardized plant extracts, provide unlimited opportunities for new drug leads because of the unmatched availability of chemical diversity. To secure ...this, a number of pivotal quality standards need to be set at the level of extract processing and primary evaluation in pharmacological screening models. This review provides a number of recommendations that will help to define a more sound ‘proof-of-concept’ for antibacterial, antifungal, antiviral and antiparasitic potential in natural products. An integrated panel of pathogens is proposed for antimicrobial profiling, using accessible standard in vitro experimental procedures, endpoint parameters and efficacy criteria. Primary requirements include: (1) use of reference strains or fully characterized clinical isolates, (2) in vitro models on the whole organism and if possible cell-based, (3) evaluation of selectivity by parallel cytotoxicity testing and/or integrated profiling against unrelated micro-organisms, (4) adequately broad dose range, enabling dose–response curves, (5) stringent endpoint criteria with IC
50-values generally below 100
μg/ml for extracts and below 25
μM for pure compounds, (6) proper preparation, storage and in-test processing of extracts, (7) inclusion of appropriate controls in each in vitro test replicate (blanks, infected and reference controls) and (8) follow-up of in vitro activity (‘hit’-status) in matching animal models (‘lead’-status).
Dry eye disease (DED) is a challenge in ophthalmology. Rat models represent valuable tools to study the pathophysiology and to develop novel treatments. A major challenge in DED research is detecting ...multiple biomarkers in a low tear volume sample. Multiplex immunoassays for DED rat research are missing. We have developed a multiplex electrochemiluminescence immunoassay (ECLIA) to detect three biomarkers for DED: MMP-9, IL-17 and ICAM-1. Tears, used as matrix, were collected from six healthy Wistar rats. Assays were run based on the U-Plex Meso Scale Diagnostics (MSD) platform, by two independent operators according to the EMA guideline on bioanalytical method validation. Linear mixed, regression models were fit to perform the statistical analysis on the range of concentrations for the chosen analytes. During optimization, it has observed that incubation time, temperature and agitation affected the robustness of the protocol. ECLIA optimum conditions include the use of antibodies at 0.5 µg/ml concentration and 1 h incubation at room temperature with shaking. Precision met the acceptance criteria in the chosen range: 1062-133 pg/ml for ICAM-1, 275-34.4 pg/ml for IL-17, 1750-219 pg/ml for MMP-9. Accuracy and linearity were acceptable for a broader range. This is the first report of a validated ECLIA that allows measurements of three relevant DED biomarkers in rat tear fluids.
It was recently proposed that bactericidal antibiotics, besides through specific drug-target interactions, kill bacteria by a common mechanism involving the production of reactive oxygen species ...(ROS). However, this mechanism involving the production of hydroxyl radicals has become the subject of a lot of debate. Since the contribution of ROS to antibiotic mediated killing most likely depends on the conditions, differences in experimental procedures are expected to be at the basis of the conflicting results. In the present study different methods (ROS specific stainings, gene-expression analyses, electron paramagnetic resonance, genetic and phenotypic experiments, detection of protein carbonylation and DNA oxidation) to measure the production of ROS upon antibiotic treatment in Burkholderia cepacia complex (Bcc) bacteria were compared. Different classes of antibiotics (tobramycin, ciprofloxacin, meropenem) were included, and both planktonic and biofilm cultures were studied. Our results indicate that some of the methods investigated were not sensitive enough to measure antibiotic induced production of ROS, including the spectrophotometric detection of protein carbonylation. Secondly, other methods were found to be useful only in specific conditions. For example, an increase in the expression of OxyR was measured in Burkholderia cenocepacia K56-2 after treatment with ciprofloxacin or meropenem (both in biofilms and planktonic cultures) but not after treatment with tobramycin. In addition results vary with the experimental conditions and the species tested. Nevertheless our data strongly suggest that ROS contribute to antibiotic mediated killing in Bcc species and that enhancing ROS production or interfering with the protection against ROS may form a novel strategy to improve antibiotic treatment.
Breakthroughs in cancer immunotherapies have demonstrated considerable success, though not without limitations. Non‐thermal plasma (NTP) for cancer therapy has been emerging as a potential adjuvant ...treatment via induction of immunogenic cell death (ICD). Cancer cells undergoing ICD stimulate a patient's immune system to mount an anticancer response. While promising, the underlying mechanisms of NTP‐induced ICD must be closely examined. Here, the interaction between non‐thermal plasma and cancerous cells is studied. The short‐lived reactive oxygen and nitrogen species (e.g., hydroxyl radicals, atomic oxygen, nitric oxide) produced by plasma are the main effectors that elicit ICD in melanoma while, surprisingly, persistent species do not. This is demonstrated in vitro using a dielectric barrier discharge plasma system and is validated in a vaccination assay in vivo. Plasma generation of reactive species appears to be dictated by the total energy. Collectively, this work provides fundamental insight into plasma interactions with biological material. Furthermore, it lays the foundation for future development of NTP systems for clinical translation. The addition of plasma systems into the existing arsenal of cancer therapies opens the possibility for new combination strategies for safer and more robust control of cancer.
An investigation into the interactions between chemical species produced by non‐thermal plasma and melanoma cells is presented. Reactive species generated by plasma that increase cancer immunogenicity are identified. This work expands the fundamental understanding of the mechanisms of plasma effects on cancer targets, which allows for further development of clinical devices.
Fused filament fabrication (FFF) 3D printing technology is widely used in many fields. For almost a decade, medical researchers have been exploring the potential use of this technology for improving ...the healthcare sector. Advances in personalized medicine have been more achievable due to the applicability of producing drug delivery devices, which are explicitly designed based on patients’ needs. For the production of these devices, a filament—which is the feedstock for the FFF 3D printer—consists of a carrier polymer (or polymers) and a loaded active pharmaceutical ingredient (API). This systematic review of the literature investigates the most widely used approaches for producing drug-loaded filaments. It also focusses on several factors, such as the polymeric carrier and the drug, loading capacity and homogeneity, processing conditions, and the intended applications. This review concludes that the filament preparation method has a significant effect on both the drug homogeneity within the polymeric carrier and drug loading efficiency.
Selected strategies to fight pathogenic bacteria Plotniece, Aiva; Sobolev, Arkadij; Supuran, Claudiu T. ...
Journal of enzyme inhibition and medicinal chemistry
38, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Natural products and analogues are a source of antibacterial drug discovery. Considering drug resistance levels emerging for antibiotics, identification of bacterial metalloenzymes and the synthesis ...of selective inhibitors are interesting for antibacterial agent development. Peptide nucleic acids are attractive antisense and antigene agents representing a novel strategy to target pathogens due to their unique mechanism of action. Antisense inhibition and development of antisense peptide nucleic acids is a new approach to antibacterial agents. Due to the increased resistance of biofilms to antibiotics, alternative therapeutic options are necessary. To develop antimicrobial strategies, optimised in vitro and in vivo models are needed. In vivo models to study biofilm-related respiratory infections, device-related infections: ventilator-associated pneumonia, tissue-related infections: chronic infection models based on alginate or agar beads, methods to battle biofilm-related infections are discussed. Drug delivery in case of antibacterials often is a serious issue therefore this review includes overview of drug delivery nanosystems.
Respiratory Syncytial Virus (RSV) poses a significant global health concern as a major cause of lower respiratory tract infections (LRTIs). Over the last few years, substantial efforts have been ...directed towards developing vaccines and therapeutics to combat RSV, leading to a diverse landscape of vaccine candidates. Notably, two vaccines targeting the elderly and the first maternal vaccine have recently been approved. The majority of the vaccines and vaccine candidates rely solely on a prefusion-stabilized conformation known for its highly neutralizing epitopes. Although, so far, this antigen design appears to be successful for the elderly, our current understanding remains incomplete, requiring further improvement and refinement in this field. Pediatric vaccines still have a long journey ahead, and we must ensure that vaccines currently entering the market do not lose efficacy due to the emergence of mutations in RSV's circulating strains. This review will provide an overview of the current status of vaccine designs and what to focus on in the future. Further research into antigen design is essential, including the exploration of the potential of alternative RSV proteins to address these challenges and pave the way for the development of novel and effective vaccines, especially in the pediatric population.
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