Carbon Quantum Dots Based on Marine Polysaccharides: Types, Synthesis, and Applications

Fluorescence 'Turn-on' Probe for Chromium Reduction, Adsorption and Detection Based on Cellulosic Nitrogen-Doped Carbon Quantum Dots Hydrogels

This paper proposes a new, highly effective fluorescence test for Cr(VI) detection. This method utilizes a hydrogel composed of hydroxyethyl cellulose (HEC), nitrogen-doped carbon quantum dots (N-CQDs), and poly(co-acrylamido-2-methyl-1-propane sulfonic acid) (AMPS). The N-CQDs were successfully synthesized using a simple microwave method, and then conjugated with HEC and AMPS. The higher adsorption (99.41%) and higher reduction rate in H1 likely stems from both the presence of N-CQDs (absent in HB) and their increased free functional groups (compared to H2/H3, where N-CQDs block them). This facilitates the release (desorption) of Cr(VI) from the hydrogels, making it more available for reduction to the less toxic Cr(III). The fluorescent brightness of the HEC-N-CQDs-g-poly(AMPS) hydrogel increases gradually when Cr(VI) is added in amounts ranging from 15 to 120 mg/L. The fluorescent enhancement of the HEC-N-CQDs-g-poly(AMPS) hydrogel appeared to exhibit a good linear relationship with the 15-120 mg of the Cr(VI) concentration, with a detection limit of 0.0053 mg/L, which is lower than the standard value published by WHO. Our study found that the HEC-N-CQDs-g-poly(AMPS) hydrogel served effectively as a fluorescent probe for Cr(VI) detection in aqueous solutions, demonstrating high sensitivity.

Biomedical potency and mechanisms of marine polysaccharides and oligosaccharides: A review

Derived from bountiful marine organisms (predominantly algae, fauna, and microorganisms), marine polysaccharides and marine oligosaccharides are intricate macromolecules that play a significant role in the growth and development of marine life. Recently, considerable attention has been paid to marine polysaccharides and marine oligosaccharides as auspicious natural products due to their promising biological attributes. Herein, we provide an overview of recent advances in the miscellaneous biological activities of marine polysaccharides and marine oligosaccharides that encompasses their anti-cancer, anti-inflammatory, antibacterial, antiviral, antioxidant, anti-diabetes mellitus, and anticoagulant properties. Furthermore, we furnish a concise summary of the underlying mechanisms governing the behavior of these biological macromolecules. We hope that this review inspires research on marine polysaccharides and marine oligosaccharides in medicinal applications while offering fresh perspectives on their broader facets.

Nanotechnology in the diagnostic and therapy for Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder primarily characterized by β-amyloid plaque, intraneuronal tangles, significant neuronal loss and cognitive deficit. Treatment in the early stages of the disease is crucial for preventing or perhaps reversing the neurodegeneration in the AD cases. However, none of the current diagnostic procedures are capable of early diagnosis of AD. Further, the available treatments merely provide symptomatic alleviation in AD and do not address the underlying illness. Therefore, there is no permanent cure for AD currently. Better therapeutic outcomes need the optimum drug concentration in the central nervous system (CNS) by traversing blood-brain-barrier (BBB). Nanotechnology offers enormous promise to transform the treatment and diagnostics of neurodegenerative diseases. Nanotechnology based diagnostic tools, drug delivery systems and theragnostic are capable of highly sensitive molecular detection, effective drug targeting and their combination. Significant work has been done in this area over the last decade and prospective results have been obtained in AD therapy. This review explores the various applications of nanotechnology in addressing the varied facets of AD, ranging from early detection to therapeutic interventions. This review also looks at how nanotechnology can help with the development of disease-modifying medicines, such as the delivery of anti-amyloid, anti-tau, cholinesterase inhibitors, antioxidants and hormonal drugs. In conclusion, this paper discusses the role of nanotechnology in the early detection of AD, effective drug targeting to the CNS and theragnostic applications in the management of AD.

Green synthesis of chlorella-derived carbon dots and their fluorescence imaging in zebrafish

Recently, carbon dots (CDs) have been shown to exhibit exceptional water solubility, low toxicity, favorable biocompatibility, stable fluorescence properties with a wide and continuous excitation spectrum, and an adjustable emission spectrum. Their remarkable characteristics make them highly promising for applications in the field of bioimaging. Zebrafish is currently extensively studied because of its high genetic homology with humans and the applicability of disease research findings from zebrafish to humans. Therefore, spirulina, a commonly used feed additive in aquaculture, was chosen as the raw material for synthesizing fluorescent CDs using a hydrothermal method. On the one hand, CDs can modulate dopamine receptors in the brain of zebrafish, leading to an increase in dopamine production and subsequently promoting their locomotor activity. On the other hand, CDs have been shown to enhance the intestinal anti-inflammatory capacity of zebrafish. This study aimed to explore the chronic toxicity and genotoxicity of CDs in zebrafish while providing valuable insights for their future application in biological and medical fields.