Generating luminescent Graphene quantum Dots from Tryptophan: Fluorosensors for hydrogen peroxide in cancer cells.

Herein, we report a single step synthesis of highly fluorescent Graphene Quantum Dots (GQDs) using tryptophan and glycerol as precursors via pyrolysis. The morphological and functional characterization of the prepared GQDs was performed using PXRD, FTIR, TEM, XPS and zeta potential measurements. The prepared GQDs found their practical application in ultrasensitive detection of an emerging potential cancer biomarker, H2O2, by exploiting the fluorescence quenching behaviour of H2O2. To evaluate the detection sensitivity, a series of various concentrations of H2O2 was spiked to biomatrices like, serum and MCF-7 (human breast cancer cell line) cell lysate medium. A remarkably low limit of detection (LOD) was found in serum medium (139.5 pM) which further improved in MCF-7 cell lysate medium (LOD 61.43 pM). Moreover, the sensing capacity of the GQDs was further validated in presence of various physiological variables such as glucose, cholesterol, insulin and nitrite. Sensing assay was also carried out in HaCaT (human keratinocyte cell line) cell lysate medium to compare the performance of our prepared sensor but the non-linearity of the F0/F versus H2O2 concentration plot pointed towards the conduciveness of the MCF-7 cell lysate medium for sensitive detection of H2O2.The mechanism behind the sensing was also explored using spectroscopic methods.

Aptamers: ushering in new hopes in targeted glioblastoma therapy.

Glioblastoma, a formidable brain cancer, has remained a therapeutic challenge due to its aggressive nature and resistance to conventional treatments. Recent data indicate that aptamers, short synthetic DNA or RNA molecules can be used in anti-cancer therapy due to their better tumour penetration, specific binding affinity, longer retention in tumour sites and their ability to cross the blood-brain barrier. With the ability to modify these oligonucleotides through the selection process, and using rational design to modify them, post-SELEX aptamers offer several advantages in glioblastoma treatment, including precise targeting of cancer cells while sparing healthy tissue. This review discusses the pivotal role of aptamers in glioblastoma therapy and diagnosis, emphasising their potential to enhance treatment efficacy and also highlights recent advancements in aptamer-based therapies which can transform the landscape of glioblastoma treatment, offering renewed hope to patients and clinicians alike.

Estimation of the prevalence and determination of risk factors associated with demodicosis in dogs.

OBJECTIVES: Demodicosis is a vital skin problem in dogs. The present study has determined the prevalence and associated risk factors of demodicosis in dogs and the response to treatment. MATERIALS AND METHODS: A total of 100 skin scrapings were collected from dogs having dermatological lesions brought to the Teaching and Training Pet Hospital and Research Center of Chattogram Veterinary and Animal Sciences University for treatment purpose. The collected scrapings were dissolved in 10% potassium hydroxide to detect mites through microscopic examination. Various risk factors like breed, age, sex, hair type, health status, and management system (indoor and outdoor) were analyzed using the logistic regression model. Positive cases were treated with oral ivermectin (Scabo®; at 0.6 mg/kg/day) along with amitraz 12.5% (Ridd®) diluted to 0.05% for rubbing on the body after bathing with chlorhexidine shampoo (PetHex®). Clavulanate amoxicillin (Moxaclav®) and omega-3 fatty acids (OMG-3®) were also suggested to prevent secondary bacterial infection and to maintain skin and hair coat integrity. The recovery rate was observed every 2-4 weeks of treatment upto 11-13 weeks. RESULTS: The overall prevalence of demodicosis was recorded as 27%. Hair type, health status, and management system were significantly (p < 0.05) associated with the occurrence of demodicosis in dogs. Following treatment, the first negative skin scraping for mite was noticed at 8-10 weeks of treatment, and in all cases, clinical signs completely disappeared at 80-90 days of treatment. CONCLUSION: A good percentage of the dogs having dermatological lesions was determined as demodicosis. Long-term oral ivermectin and topical amitraz, an oral antibiotic, and nutritional therapy are effective against canine demodicosis. Keeping long-haired dogs with good body condition and indoor management is highly suggestive of preventing and controlling the disease.

Pro-Oxidant Therapeutic Activities of Cerium Oxide Nanoparticles in Colorectal Carcinoma Cells.

Given that basal levels of reactive oxygen species (ROS) are higher in cancer cells, there is a growing school of thought that endorses pro-oxidants as potential chemotherapeutic agents. Intriguingly, cerium oxide (CeO2) nanoparticles can manifest either anti- or pro-oxidant activity as a function of differential pH of various subcellular localizations. In an acidic pH environment, for example, in extracellular milieu of cancer cells, CeO2 would function as a pro-oxidant. Based on this concept, the present study is designed to investigate the pro-oxidant activities of CeO2 in human colorectal carcinoma cell line (HCT 116). For comparison, we have also studied the effect of ceria nanoparticles on human embryonic kidney (HEK 293) cells. Dose-dependent viability of cancerous as well as normal cells has been assessed by treating them independently with CeO2 nanoparticles of different concentrations (5-100 µg/mL) in the culture media. The half maximal inhibitory concentration (IC50) of nanoceria for HCT 116 is found to be 50.48 µg/mL while that for the HEK 293 cell line is 92.03 µg/mL. To understand the intricate molecular mechanisms of CeO2-induced cellular apoptosis, a series of experiments have been conducted. The apoptosis-inducing ability of nanoceria has been investigated by Annexin V-FITC staining, caspase 3/9 analysis, cytochrome c release, intracellular ROS analysis, and mitochondrial membrane potential analysis using flow cytometry. Experimental data suggest that CeO2 treatment causes DNA fragmentation through enhanced generation of ROS, which ultimately leads to cellular apoptosis through the p53-dependent mitochondrial signaling pathway.

Optimization of cellulase production from bacteria isolated from soil.

Cellulase-producing bacteria were isolated from soil and identified as Pseudomonas fluorescens, Bacillus subtilIs, E. coli, and Serratia marcescens. Optimization of the fermentation medium for maximum cellulase production was carried out. The culture conditions like pH, temperature, carbon sources, and nitrogen sources were optimized. The optimum conditions found for cellulase production were 40°C at pH 10 with glucose as carbon source and ammonium sulphate as nitrogen source, and coconut cake stimulates the production of cellulase. Among bacteria, Pseudomonas fluorescens is the best cellulase producer among the four followed by Bacillus subtilis, E. coli, and Serratia marscens.