A Clinical Trial on the Welfare Effects of Administering Meloxicam to 10 to 21 Day Dairy Calves Following Caustic Paste Disbudding.

Caustic paste disbudding (CPD) is widely utilized for calves, which has been known to result in adverse effects on the calves and ethical concerns related to animal welfare, despite the use of local anesthetics. The administration of meloxicam has been demonstrated to provide benefits in alleviating pain and inflammation in juvenile calves under 9 d old and subjected to CPD. Nonetheless, there is a scarcity of literature documenting the beneficial impact of meloxicam in alleviating pain in calves aged over 9 d that have undergone CPD. Therefore, the objective of this clinical trial was to evaluate the efficacy of administering meloxicam and lidocaine for cornual nerve block together in mitigating the deleterious effects of CPD, as opposed to using lidocaine alone in calves older than 9 d. Thirty Holstein calves, aged between 10 and 21 d, were enrolled and randomly assigned to 1 of 2 treatments: lidocaine alone (Placebo), lidocaine and normal saline treatment before CPD, and lidocaine plus meloxicam, lidocaine and 0.5 mg/kg of meloxicam treatment prior to CPD. The researchers were blind to the treatment of calves to control the subjective error. The occurrences of actions associated with pain, which included head shaking, head rubbing, ear flicking, tail flicking, kicking, and head passing through the fence, were recorded. Physiological performance, including the respiration rate, heart rate, rectal temperature, mechanical nociceptive threshold (MNT), food intake, and daily activity level, was monitored. Hematological conditions were ascertained through the use of routine blood tests and enzyme-linked immunosorbent assay. The generalized linear mixed model was employed to analyze the data. The research findings revealed that applying the CPD procedure significantly elevated the frequencies of tail flicking, head shaking, and kicking, resulted in increases in respiratory rate, heart rate, daily active steps, and food intake and a decrease in MNT, and led to alterations in hematological markers, including platelet counts, mean platelet volume, prostaglandin E2, constitutive nitric oxide synthase, and hydroxyl radical. Considerable benefits, such as lower heart rates, higher food intake, and MNTs, as well as lower levels of white blood cell counts, lymphocyte counts, hemoglobin, mean platelet volume, prostaglandin E2, tumor necrosis factor-α, constitutive nitric oxide synthase, malondialdehyde, and hydroxyl radical, were observed in the calves that received meloxicam treatment in response to CPD. The findings of the study indicate that the co-administration of lidocaine and meloxicam provides obvious benefits in mitigating pain, inflammation, and oxidative stress in calves aged over 9 d and undergoing CPD. This endorses the use of meloxicam during the disbudding and dehorning procedures of calves.

Caustic paste disbudding (CPD) is a widely used practice in the cattle industry, yet there is a shortage of literature on the effects of meloxicam on calves aged 10 to 21 d who have undergone this procedure. In this clinical trial, we conducted a comparative analysis of the pain-related behavioral, physiological, and hematological performance of calves that were administered with either lidocaine plus normal saline (n = 15) or lidocaine plus meloxicam (n = 15) before undergoing disbudding operations. The findings demonstrated that the CPD operation had a significant impact on the pain-related behavior, physiological functions, and serum anti-inflammatory and antioxidative markers of the calves. On the other hand, the administration of meloxicam had notable advantages for the calves by enhancing the physiological and hematological parameters.

Iron oxide-EDTA nanoparticles for chelation-enhanced chemodynamic therapy and ion interference therapy.

As an emerging anti-tumor strategy, chemodynamic therapy (CDT) utilizes a Fenton/Fenton-like reaction to generate highly toxic hydroxyl radicals to kill tumor cells. However, the efficiency of CDT is still hindered by the low Fenton/Fenton-like reaction rate. Herein, we report the combination of ion interference therapy (IIT) and chemodynamic therapy (CDT) via an amorphous iron oxide (AIO) nanomedicine with encapsulated EDTA-2Na (EDTA). Iron ions and EDTA are released from the nanomedicine in acidic tumors and chelate to form iron ion-EDTA, which improves the efficiency of CDT and promotes the generation of reactive oxygen species (ROS). In addition, EDTA can disrupt the homeostasis of Ca2+ in tumor cells by chelating with Ca2+ ions, which induces the separation of tumor cells and affects normal physiological activities. Both in vitro and in vivo experiments show that the nano chelating drugs exhibit significant improvement in Fenton reaction performance and excellent anti-tumor activity. This study based on chelation provides a new idea for designing efficient catalysts to enhance the Fenton reaction and provides more revelations on future research on CDT.

Platelets Inhibit Methicillin-Resistant Staphylococcus aureus by Inducing Hydroxyl Radical-Mediated Apoptosis-Like Cell Death.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common drug-resistant bacteria and poses a significant threat to human health. Due to the emergence of multidrug resistance, limited drugs are available for the treatment of MRSA infections. In recent years, platelets have been reported to play important roles in inflammation and immune responses, in addition to their functions in blood hemostasis and clotting. We and other researchers have previously reported that platelets can inhibit Staphylococcus aureus growth. However, it remained unclear whether platelets have the same antibacterial effect on drug-resistant strains. In this study, we hypothesized that platelets may also inhibit the growth of MRSA; the results confirmed that platelets significantly inhibited the growth of MRSA in vitro. In a murine model of MRSA infection, we found that a platelet transfusion alleviated the symptoms of MRSA infection; in contrast, depletion of platelets aggravated infective symptoms. Moreover, we observed an overproduction of hydroxyl radicals in MRSA following platelet treatment, which induced apoptosis-like death of MRSA. Our findings demonstrate that platelets can inhibit MRSA growth by promoting the overproduction of hydroxyl radicals and inducing apoptosis-like death. IMPORTANCE The widespread use of antibiotics has led to the emergence of drug-resistant bacteria, particularly multidrug-resistant bacteria. MRSA is the most common drug-resistant bacterium that causes suppurative infections in humans. As only a limited number of drugs are available to treat the infections caused by drug-resistant pathogens, it is imperative to develop novel and effective biological agents for treating MRSA infections. This is the first study to show that platelets can inhibit MRSA growth in vitro and in vivo. Our results revealed that platelets enhanced the production of hydroxyl radicals in MRSA, which induced a series of apoptosis hallmarks in MRSA, including DNA fragmentation, chromosome condensation, phosphatidylserine exposure, membrane potential depolarization, and increased intracellular caspase activity. These findings may further our understanding of platelet function.

Ferrocene and glucose oxidase-installed multifunctional hydrogel reactors for local cancer therapy.

A hyaluronic acid (HA)-based one-pot hydrogel reactor with single syringe injection and immediate gelation was developed for starvation therapy (ST), chemodynamic therapy (CDT), ferroptosis, and photothermal therapy (PTT) against breast cancer. A rheologically tuned hydrogel network, composed of HA-phenylboronic acid (HP) and HA-dopamine (HD), was designed by introducing a boronate ester linkage (phenylboronic acid-dopamine interaction) and polydopamine bond (pH control). Ferrocene (Fc)-conjugated HP (Fc-HP) was synthesized to achieve ferroptosis, Fenton reaction-involved toxic hydroxyl radical (•OH) generation, and photothermal ablation in cancer therapy. Glucose oxidase (GOx) was entrapped in the pH-modulated Fc-HP (Fc-HP°)/HD hydrogel network for converting intracellular glucose to H2O2 to enable its own supply. The GOx/Fc combination-installed hydrogel reactor system can provide sustained ST/CDT/PTT functions along with ferroptosis. Injection of Fc-HP°/HD/GOx hydrogel with single-syringe injectability, shear-thinning feature, and self-healing capability offered a slow biodegradation rate and high safety profiles. Peritumorally injected Fc-HP°/HD/GOx hydrogel also efficiently suppressed the growth of breast cancer based on multifunctional therapeutic approaches with reduced dosing frequency. Hyperthermia induced by near-infrared (NIR) laser absorption may amplify the therapeutic effects of free radicals. It is expected that this Fc-HP°/HD/GOx hydrogel system can be applied to local cancer therapy with high efficacy and safety profiles.

Harnessing inorganic nanomaterials for chemodynamic cancer therapy.

The most important aspect of chemodynamic therapy (CDT) is the harnessing of Fenton or Fenton-like chemistry for cancer therapy within the tumor microenvironment, which occurs because of the moderate acidity and overexpressed H2O2 in the tumor microenvironment. Hydroxyl radicals (•OH) produced within tumor cells via Fenton and Fenton-like reactions cause cancer cell death. Reactive oxygen species-mediated CDT demonstrates a desired anticancer impact without the need for external stimulation or the development of drug resistance. Cancer therapy based on CDT is known as a viable cancer therapy modality. This review discusses the most recent CDT advancements and provides some typical instances. As a result, potential methods for further improving CDT efficiency under the guidance of Fenton chemistry are offered.

Cancer is one of the leading causes of death worldwide. Unfortunately, conventional treatments do not greatly increase the quality of life or survival rate of cancer patients. So, coming up with new, less invasive ways to treat cancer would be an important way to increase the number of cancer patients who survive. Chemodynamic therapy, a new cancer treatment modality, uses intracellular hydrogen peroxide as a fantastic 'Trojan horse' to produce highly toxic hydroxyl radicals (^•OH) to kill cancer cells. This review discusses the most recent advancements in chemodynamic therapy and provides some typical instances.

Manipulating Intratumoral Fenton Chemistry for Enhanced Chemodynamic and Chemodynamic-Synergized Multimodal Therapy.

Chemodynamic therapy (CDT) uses the tumor microenvironment-assisted intratumoral Fenton reaction for generating highly toxic hydroxyl free radicals (•OH) to achieve selective tumor treatment. However, the limited intratumoral Fenton reaction efficiency restricts the therapeutic efficacy of CDT. Recent years have witnessed the impressive development of various strategies to increase the efficiency of intratumoral Fenton reaction. The introduction of these reinforcement strategies can dramatically improve the treatment efficiency of CDT and further promote the development of enhanced CDT (ECDT)-based multimodal anticancer treatments. In this review, the authors systematically introduce these reinforcement strategies, from their basic working principles, reinforcement mechanisms to their representative clinical applications. Then, ECDT-based multimodal anticancer therapy is discussed, including how to integrate these emerging Fenton reinforcement strategies for accelerating the development of multimodal anticancer therapy, as well as the synergistic mechanisms of ECDT and other treatment methods. Eventually, future direction and challenges of ECDT and ECDT-based multimodal synergistic therapies are elaborated, highlighting the key scientific problems and unsolved technical bottlenecks to facilitate clinical translation.

Cisplatin-induced hydroxyl radicals mediate pro-survival autophagy in human lung cancer H460 cells.

BACKGROUND: Accumulated evidence demonstrates cisplatin, a recommended chemotherapy, modulating pro-survival autophagic response that contributes to treatment failure in lung cancer patients. However, distinct mechanisms involved in cisplatin-induced autophagy in human lung cancer cells are still unclear. RESULTS: Herein, role of autophagy in cisplatin resistance was indicated by a decreased cell viability and increased apoptosis in lung cancer H460 cells pre-incubated with wortmannin, an autophagy inhibitor, prior to treatment with 50 µM cisplatin for 24 h. The elevated level of hydroxyl radicals detected via flow-cytometry corresponded to autophagic response, as evidenced by the formation of autophagosomes and autolysosomes in cisplatin-treated cells. Interestingly, apoptosis resistance, autophagosome formation, and the alteration of the autophagic markers, LC3-II/LC3-I and p62, as well as autophagy-regulating proteins Atg7 and Atg3, induced by cisplatin was abrogated by pretreatment of H460 cells with deferoxamine, a specific hydroxyl radical scavenger. The modulations in autophagic response were also indicated in the cells treated with hydroxyl radicals generated via Fenton reaction, and likewise inhibited by pretreatment with deferoxamine. CONCLUSIONS: In summary, the possible role of hydroxyl radicals as a key mediator in the autophagic response to cisplatin treatment, which was firstly revealed in this study would benefit for the further development of novel therapies for lung cancer.

Self-Assembly of Copper-DNAzyme Nanohybrids for Dual-Catalytic Tumor Therapy.

Despite the great efforts of using DNAzyme for gene therapy, its clinical success is limited by the lack of simple delivery systems and limited anticancer efficacy. Here, we develop a simple approach for the synthesis of hybrid nanostructures that exclusively consist of DNAzyme and Cu2+ with ultra-high loading capacity. The Cu-DNAzyme nanohybrids allow to effectively co-deliver DNAzyme and Cu2+ into cancer cells for combinational catalytic therapy. The released Cu2+ can be reduced to Cu+ by glutathione and then catalyze endogenous H2 O2 to form cytotoxic hydroxyl radicals for chemodynamic therapy (CDT), while the 10-23 DNAzyme enables the catalytic cleavage of VEGFR2 mRNA and activates gene silencing for gene therapy. We demonstrate that the system can efficiently accumulate in the tumor and exhibit amplified cascade antitumor effects with negligible systemic toxicity. Our work paves an extremely simple way to integrate DNAzyme with CDT for the dual-catalytic tumor treatment.

Cisplatin-induced hydroxyl radicals mediate pro-survival autophagy in human lung cancer H460 cells

BACKGROUND: Accumulated evidence demonstrates cisplatin, a recommended chemotherapy, modulating pro-survival autophagic response that contributes to treatment failure in lung cancer patients. However, distinct mechanisms involved in cisplatin-induced autophagy in human lung cancer cells are still unclear. RESULTS: Herein, role of autophagy in cisplatin resistance was indicated by a decreased cell viability and increased apoptosis in lung cancer H460 cells pre-incubated with wortmannin, an autophagy inhibitor, prior to treatment with 50 µM cisplatin for 24 h. The elevated level of hydroxyl radicals detected via flow-cytometry corresponded to autophagic response, as evidenced by the formation of autophagosomes and autolysosomes in cisplatin-treated cells. Interestingly, apoptosis resistance, autophagosome formation, and the alteration of the autophagic markers, LC3-II/LC3-I and p62, as well as autophagy-regulating proteins Atg7 and Atg3, induced by cisplatin was abrogated by pretreatment of H460 cells with deferoxamine, a specific hydroxyl radical scavenger. The modulations in autophagic response were also indicated in the cells treated with hydroxyl radicals generated via Fenton reaction, and likewise inhibited by pretreatment with deferoxamine. CONCLUSIONS: In summary, the possible role of hydroxyl radicals as a key mediator in the autophagic response to cisplatin treatment, which was firstly revealed in this study would benefit for the further development of novel therapies for lung cancer.

A mitochondria-targeting photothermogenic nanozyme for MRI-guided mild photothermal therapy.

Iridium complexes were used as a mitochondria-targeting agent to modify the surface of a photothermogenic nanozyme Fe3O4 nanoparticles (Ir@Fe3O4 NPs). Upon NIR irradiation, Ir@Fe3O4 NPs increase the localized temperature to 42 °C which accelerates the catalysis of ˙OH production from H2O2 resulting in excellent mild photothermal therapy.

Multifunctional hetero-nanostructures of hydroxyl-rich polycation wrapped cellulose-gold hybrids for combined cancer therapy.

The development of new hetero-nanostructures for multifunctional applications in cancer therapy has attracted widespread attention. In this work, we put forward a facile approach to synthesize multifunctional hetero-nanostructures of cellulose nanocrystal (CNC)-gold nanoparticle hybrids wrapped with low-toxic hydroxyl-rich polycations to integrate versatile functions for effective cancer therapy. Biocompatible CNCs with the superior rod-like morphology for high cellular uptake were employed as substrates to flexibly load spherical gold nanoparticles (Au NPs) or gold nanorods (Au NRs) through gold-thiolate bonds, producing hetero-layered nanohybrids of CNC-Au NPs or CNC-Au NRs. Profound hydroxyl-rich cationic gene carrier, CD-PGEA (comprising ß-cyclodextrin cores and ethanolamine-functionalized poly(glycidyl methacrylate) arms), was then assembled onto the surface of CNC-Au nanohybrids through host-guest interaction and gold-thiolate bonds, where PEG was employed as the intermediate and spacer. The resultant CNC-Au-PGEA hetero-nanostructures exhibited excellent performances as gene carriers. Furthermore, CNC-Au NR-PGEA comprising Au NRs demonstrated favorable optical absorption properties and were validated for photoacoustic imaging and combined photothermal/gene therapy with considerable antitumor effects. The present work provided a flexible strategy for the construction of new multifunctional hetero-nanostructures with high antitumor efficacy.

Free radical-scavenging activity of Crassostera gigas extract (JCOE).

In the present study, we evaluate the free radical-scavenging activity of JCOE (Japan clinic oyster extract), a powder extracted from Crassostera gigas by a spin-trapping method using electron paramagnetic resonance (EPR), and also estimate the protective effect against gastric mucosal cell injury induced by hydrogen peroxide. The EPR study demonstrated that JCOE directly scavenged superoxide radical as well as hydroxyl radical in a concentration-dependent manner. After exposure to hydrogen peroxide for 4 h in Hank's balanced buffered solution, cell viability of rat gastric mucosal cells (RGM-1) was measured by modified MTT assay. Hydrogen peroxide-induced injury was not reversed by 1-h preincubation with 100 to 1,000 micrograms/mL JCOE solution which has high reactivity to hydroxyl radicals, indicating that the active ingredients, including taurine of JCOE on scavenging action of hydroxyl radical, did not penetrate cell membranes easily. Twenty-four hour pretreatment with the JCOE solution significantly reversed the decrease in cell viability induced by hydrogen peroxide, indicating the possibility that JCOE solution may stimulate the endogenous eliminating system against hydrogen peroxide.