Biogenic carbon quantum dots from marine endophytic fungi (Aspergillus flavus) to enhance the curcumin production and growth in Curcuma longa L

In this study, we have investigated the effect of carbon quantum dots (FM-CQDs) synthesized from marine fungal extract on Curcuma longa to improve the plant growth and curcumin production. The isolated fungus, Aspergillus flavus has produced a high amount of indole-3-acetic acid (IAA) (0.025 mg g-1), when treated with tryptophan. CQDs were synthesized from the A. flavus extract and it was characterized using ultraviolet visible spectrophotometer (UV-Vis) and high-resolution transmission electron microscopy (HR-TEM). The synthesized CQDs were excited at 365 nm in an UV-Vis and the HR-TEM analysis showed approximately 7.4 nm in size with a spherical shape. Both fungal crude extract (FCE) at 0-100 mg L-1 and FM-CQDs 0-5 mg L-1 concentrations were tested on C. longa. About 80 mg L-1 concentration FCE treated plants has shown a maximum height of 21 cm and FM-CQDs at 4 mg L-1 exhibited a maximum height of 25 cm compared to control. The FM-CQDs significantly increased the photosynthetic pigments such as total chlorophyll (1.08 mg g-1 FW) and carotenoids (17.32 mg g-1 FW) in C. longa. Further, antioxidant enzyme analysis confirmed that the optimum concentrations of both extracts did not have any toxic effects on the plants. FM-CQDs treated plants increased the curcumin content up to 0.060 mg g-1 by HPLC analysis. Semi quantitative analysis revealed that FCE and FM-CQDs significantly upregulated ClCURS1 gene expression in curcumin production.

Theranostics: a multifaceted approach utilizing nano-biomaterials

Biomaterials play a vital role in targeting therapeutics. Over the years, several biomaterials have gained wide attention in the treatment and diagnosis of diseases. Scientists are trying to make more personalized treatments for different diseases, as well as discovering novel single agents that can be used for prognosis, medication administration, and keeping track of how a treatment works. Theranostics based on nano-biomaterials have higher sensitivity and specificity for disease management than conventional techniques. This review provides a concise overview of various biomaterials, including carbon-based materials like fullerenes, graphene, carbon nanotubes (CNTs), and carbon nanofibers, and their involvement in theranostics of different diseases. In addition, the involvement of imaging techniques for theranostics applications was overviewed. Theranostics is an emerging strategy that has great potential for enhancing the accuracy and efficacy of medicinal interventions. Despite the presence of obstacles such as disease heterogeneity, toxicity, reproducibility, uniformity, upscaling production, and regulatory hurdles, the field of medical research and development has great promise due to its ability to provide patients with personalised care, facilitate early identification, and enable focused treatment.

Nanozymes and carbon-dots based nanoplatforms for cancer imaging, diagnosis and therapeutics: Current trends and challenges

Cancer patients face a significant clinical and socio-economic burden due to increased incidence, mortality, and poor survival. Factors like late diagnosis, recurrence, drug resistance, severe side effects, and poor bioavailability limit the scope of current therapies. There is a need for novel, cost-effective, and safe diagnostic methods, therapeutics to overcome recurrence and drug resistance, and drug delivery vehicles with enhanced bioavailability and less off-site toxicity. Advanced nanomaterial-based research is aiding cancer biologists by providing solutions for issues like hypoxia, tumor microenvironment, low stability, poor penetration, target non-specificity, and rapid drug clearance. Currently, nanozymes and carbon-dots are attractive due to their low cost, high catalytic activity, biocompatibility, and lower toxicity. Nanozymes and carbon-dots are increasingly used in imaging, biosensing, diagnosis, and targeted cancer therapy. Integrating these materials with advanced diagnostic tools like CT scans and MRIs can aid in clinical decision-making and enhance the effectiveness of chemotherapy, photothermal, photodynamic, and sonodynamic therapies, with minimal invasion and reduced collateral effects.

Multifunctional Carbon Dots for Biomedical Applications: Diagnosis, Therapy, and Theranostic

Designing suitable nanomaterials is an ideal strategy to enable early diagnosis and effective treatment of diseases. Carbon dots (CDs) are luminescent carbonaceous nanoparticles that have attracted considerable attention. Through facile synthesis, they process properties including tunable light emission, low toxicity, and light energy transformation, leading to diverse applications as optically functional materials in biomedical fields. Recently, their potentials have been further explored, such as enzyme-like activity and ability to promote osteogenic differentiation. Through refined synthesizing strategies carbon dots, a rich treasure trove for new discoveries, stand a chance to guide significant development in biomedical applications. In this review, the authors start with a brief introduction to CDs. By presenting mechanisms and examples, the authors focus on how they can be used in diagnosing and treating diseases, including bioimaging failure of tissues and cells, biosensing various pathogenic factors and biomarkers, tissue defect repair, anti-inflammation, antibacterial and antiviral, and novel oncology treatment. The introduction of the application of integrated diagnosis and treatment follows closely behind. Furthermore, the challenges and future directions of CDs are discussed. The authors hope this review will provide critical perspectives to inspire new discoveries on CDs and prompt their advances in biomedical applications.

Mini review about metal organic framework (MOF)-based wearable sensors: Challenges and prospects

Among many types of wearable sensors, MOFs-based wearable sensors have recently been explored in both commercialization and research. There has been much effort in various aspects of the development of MOF-based wearable sensors including but not limited to miniaturization, size control, safety, improvements in conformal and flexible features, improvements in the analytical performance and long-term storage of these devices. Recent progress in the design and deployment of MOFs-based wearable sensors are covered in this paper, as are the remaining obstacles and prospects. This work also highlights the enormous potential for synergistic effects of MOFs used in combination with other nanomaterials for healthcare applications and raise attention toward the economic aspect and market diffusion of MOFs-based wearable sensors.

Comprehensive advances in the synthesis, fluorescence mechanism and multifunctional applications of red-emitting carbon nanomaterials

Red emitting fluorescent carbon nanomaterials have drawn significant scientific interest in recent years due to their high quantum yield, water-dispersibility, photostability, biocompatibility, ease of surface functionalization, low cost and eco-friendliness. The red emissive characteristics of fluorescent carbon nanomaterials generally depend on the carbon source, reaction time, synthetic approach/methodology, surface functional groups, average size, and other reaction environments, which directly or indirectly help to achieve red emission. The importance of several factors to achieve red fluorescent carbon nanomaterials is highlighted in this review. Numerous plausible theories have been explained in detail to understand the origin of red fluorescence and tunable emission in these carbon-based nanostructures. The above advantages and fluorescence in the red region make them a potential candidate for multifunctional applications in various current fields. Therefore, this review focused on the recent advances in the synthesis approach, mechanism of fluorescence, and electronic and optical properties of red-emitting fluorescent carbon nanomaterials. This review also explains the several innovative applications of red-emitting fluorescent carbon nanomaterials such as biomedicine, light-emitting devices, sensing, photocatalysis, energy, anticounterfeiting, fluorescent silk, artificial photosynthesis, etc. It is hoped that by choosing appropriate methods, the present review can inspire and guide future research on the design of red emissive fluorescent carbon nanomaterials for potential advancements in multifunctional applications.

Green synthesis of gardenia seeds-based carbon dots for bacterial imaging and antioxidant activity in aqueous and oil samples

In this work, luminescent carbon dots with gardenia seeds as carbon precursors (GCDs) were synthesized using a one-step mild pyrolysis process and were then used as probes for imaging of bacterial (Escherichia coli). The GCDs showed a strong emission at 430 nm when excited at 370 nm. The relative fluorescence quantum yield of GCDs was found to be 1.13% in an aqueous medium. Rapid internalization of the GCDs by bacteria was confirmed by three colors (blue, green, and yellow) images that were obtained using confocal fluorescence microscopy. In addition, GCDs were noted to exhibit potent scavenging activities against DPPH˙, ˙OH, and ˙O2- free radicals. GCDs were also assayed as antioxidants in an oil sample by volumetric determination of the peroxide value. Thus, GCDs exhibited good antioxidant properties both in aqueous and oil media. In addition, a free fatty acid quantification kit in the presence of GCDs showed enhanced fluorescence detection of palmitic acid with a remarkably good limit of detection of 0.08 μM, which is lower than that in the absence of GCDs (0.76 μM). The proposed fluorescence method was then successfully used to determine the concentration of palmitic acid spiked in milk powder samples, with spiked recoveries of 82.6-109.6% and relative standard deviations of 0.9-4.6%.

Fluorescence of D-Glucose-Derived Carbon Dots: Effect of Process Parameters

The aim of this study was to synthesize highly fluorescent carbon dots (CDs) from glucose using a microwave hydrothermal method. It explored the impact of glucose concentration, process time, molar ratio of KH2PO4 to glucose, and homogenization time on the resulting CDs, employing a fractional plan 3(k-1) with four independent parameters for twenty-seven synthesis. Results showed that longer process times at 200°C increased the fluorescence intensity of the CDs. The molar ratio of KH2PO4 to glucose, glucose concentration, and process time significantly influenced fluorescence. Homogenization was crucial for obtaining small particles, though an anti-aggregation agent might still be needed. UV-vis spectroscopy, spectrofluorimetry, and DLS were used to analyze the synthesized CDs. The UV-vis absorption maxima were observed around 230 nm and 282 nm, with peak shifts at different excitation wavelengths. Out of the twenty-seven samples, six CDs samples were identified to be below 10 nm and a total of twelve below 50 nm. Analyzing the results, the study concluded that the CDs possess strong fluorescence and are suitable for diverse applications. For enhanced fluorescence, longer process times at 200°C and the use of KH2PO4 were recommended, while shorter processes were preferred for obtaining smaller particles. Hierarchical clustering, the k-means method, Pareto charts, and profiles for predicted values and desirability were used to analyze the results. It was confirmed that higher fluorescence is favored by longer process time at 200°C and the use of KH2PO4. In order to obtain smaller particles, shorter processes should be used.

π-Conjugated Polymer Nanoparticles from Design, Synthesis to Biomedical Applications: Sensing, Imaging, and Therapy

In the past decade, π-conjugated polymer nanoparticles (CPNs) have been considered as promising nanomaterials for biomedical applications, and are widely used as probe materials for bioimaging and drug delivery. Due to their distinctive photophysical and physicochemical characteristics, good compatibility, and ease of functionalization, CPNs are gaining popularity and being used in more and more cutting-edge biomedical sectors. Common synthetic techniques can be used to synthesize CPNs with adjustable particle size and dispersion. More importantly, the recent development of CPNs for sensing and imaging applications has rendered them as a promising device for use in healthcare. This review provides a synopsis of the preparation and functionalization of CPNs and summarizes the recent advancements of CPNs for biomedical applications. In particular, we discuss their major role in bioimaging, therapeutics, fluorescence, and electrochemical sensing. As a conclusion, we highlight the challenges and future perspectives of biomedical applications of CPNs.

Recent developments in carbon dots: a biomedical application perspective

Recently, newly developed carbon-based nanomaterials known as carbon dots (CDs) have generated significant interest in nanomedicine. However, current knowledge regarding CD research in the biomedical field is still lacking. An overview of the most recent development of CDs in biomedical research is given in this review article. Several crucial CD applications, such as biosensing, bioimaging, cancer therapy, and antibacterial applications, are highlighted. Finally, CD-based biomedicine's challenges and future potential are also highlighted to enrich biomedical researchers' knowledge about the potential of CDs and the need for overcoming various technical obstacles.

Recent advances in green carbon dots (2015-2022): synthesis, metal ion sensing, and biological applications

Carbon dots (CDs) show extensive potential in various fields such as sensing, bioimaging, catalysis, medicine, optoelectronics, and drug delivery due to their unique properties, that is, low cytotoxicity, cytocompatibility, water-solubility, multicolor wavelength tuned emission, photo-stability, easy modification, strong chemical inertness, etc. This review article especially focuses on the recent advancement (2015-2022) in the green synthesis of CDs, their application in metal ions sensing and microbial bioimaging, detection, and viability studies as well as their applications in pathogenic control and plant growth promotion.

Blood-brain barrier penetrating carbon dots with intrinsic anti-inflammatory and drug-loading properties

The blood-brain barrier (BBB) is the major obstacle limiting the reach of therapeutic drugs into the brain. Herein, an aspirin-based anti-inflammatory replenisher (aspCD) was fabricated by carbonizing aspirin to deliver drugs into the brain visually. The as-prepared aspCD combined the BBB-penetrating and anti-inflammatory effects of aspirin with the fluorescent and drug-loading properties of carbon dots (CDs), thereby delivering therapeutic drugs into the brain and acting as imaging agent as well as anti-inflammatory replenisher. In vivo experiments of mice and zebrafish revealed that fluorescence aspCD could effectively penetrate BBB. In vitro and in vivo inflammatory models demonstrated that aspCD could be regarded as an excellent anti-inflammatory replenisher. In addition, as a functional carrier, aspCD was proved to be capable of loading drugs with different polarity. In summary, carbonization of active precursors (therapeutic drugs) into CDs could be a promising strategy to achieve the loading and visualization of drugs as well as the retainment of their biological activities.

Green synthesis of multifunctional carbon quantum dots: An approach in cancer theranostics

Carbon quantum dots (CQDs) have gained significant growing attention in the recent past due to their peculiar characteristics including smaller size, high surface area, photoluminescence, chemical stability, facile synthesis and functionalization possibilities. They are carbon nanostructures having less than 10 nm size with fluorescent properties. In recent years, the scientific community is curiously adopting biomass precursors for the preparation of CQDs over the chemical compounds. These biomass sources are sustainable, eco-friendly, inexpensive, widely available and convert waste into valuable materials. Hence in our work the fundamental understating of diverse fabrication methodologies of CQDs, and the types of raw materials employed in recent times, are all examined and correlated comprehensively. Their unique combination of remarkable properties, together with the ease with which they can be fabricated, makes CQDs as promising materials for applications in diverse biomedical fields, in particular for bio-imaging, targeted drug delivery and phototherapy for cancer treatment. The mechanism for luminescence is of considerable significance for leading the synthesis of CQDs with tunable fluorescence emission. Therefore, it is aimed to explore and provide an updated review on (i) the recent progress on the different synthesis methods of biomass-derived CQDs, (ii) the contribution of surface states or functional groups on the luminescence origin and (iii) its potential application for cancer theranostics, concentrating on their fluorescence properties. Finally, we explored the challenges in modification for the synthesis of CQDs from biomass derivatives and the future scope of CQDs in phototherapy for cancer theranostics.

TFEB-lysosome pathway activation is associated with different cell death responses to carbon quantum dots in Kupffer cells and hepatocytes

Background

Carbon dot has been widely used in biomedical field as a kind of nanomaterial with low toxicity and high biocompatibility. CDs has demonstrated its unique advantages in assisted drug delivery, target diagnosis and targeted therapy with its small size and spontaneous fluorescence. However, the potential biosafety of CDs cannot be evaluated. Therefore, we focused on the study of liver, the target organ involved in CDs metabolism, to evaluate the risk of CDs in vitro.

Methods and results

Liver macrophage KUP5 cells and normal liver cells AML12 cells were incubated in CDs at the same concentration for 24 h to compare the different effects under the same exposure conditions. The study found that both liver cell models showed ATP metabolism disorder, membrane damage, autophagosome formation and lysosome damage, but the difference was that, KUP5 cells exhibited more serious damage than AML12 cells, suggesting that immunogenic cell type is particularly sensitive to CDs. The underlying mechanism of CDs-induced death of the two hepatocyte types were also assessed. In KUP5 cells, death was caused by inhibition of autophagic flux caused by autophagosome accumulation, this process that was reversed when autophagosome accumulation was prevented by 3-MA. AML12 cells had no such response, suggesting that the accumulation of autophagosomes caused by CDs may be specific to macrophages.

Conclusion

Activation of the TFEB-lysosome pathway is important in regulating autophagy and apoptosis. The dual regulation of ERK and mTOR phosphorylation upstream of TFEB influences the death outcome of AML12 cells. These findings provide a new understanding of how CDs impact different liver cells and contribute to a more complete toxicological safety evaluation of CDs.

Carbon Nanomaterials (CNMs) and Enzymes: From Nanozymes to CNM-Enzyme Conjugates and Biodegradation

Carbon nanomaterials (CNMs) and enzymes differ significantly in terms of their physico-chemical properties—their handling and characterization require very different specialized skills. Therefore, their combination is not trivial. Numerous studies exist at the interface between these two components—especially in the area of sensing—but also involving biofuel cells, biocatalysis, and even biomedical applications including innovative therapeutic approaches and theranostics. Finally, enzymes that are capable of biodegrading CNMs have been identified, and they may play an important role in controlling the environmental fate of these structures after their use. CNMs’ widespread use has created more and more opportunities for their entry into the environment, and thus it becomes increasingly important to understand how to biodegrade them. In this concise review, we will cover the progress made in the last five years on this exciting topic, focusing on the applications, and concluding with future perspectives on research combining carbon nanomaterials and enzymes.