Solvent-Free Synthesis of Fluorescent Carbon Dots: An Ecofriendly Approach for the Bioimaging and Screening of Anticancer Activity via Caspase-Induced Apoptosis

Current nanocomposite advances for biomedical and environmental application diversity

Nanocomposite materials are emerging as key players in addressing critical challenges in healthcare, energy storage, and environmental remediation. These innovative systems hold great promise in engineering effective solutions for complex problems. Nanocomposites have demonstrated various advantages such as simplicity, versatility, lightweight, and potential cost-effectiveness. By reinforcing synthetic and natural polymers with nanomaterials, a range of nanocomposites have exhibited unique physicochemical properties, biocompatibility, and biodegradability. Current research on nanocomposites has demonstrated promising clinical and translational applications. Over the past decade, the production of nanocomposites has emerged as a critical nano-structuring methodology due to their adaptability and controllable surface structure. This comprehensive review article systematically addresses two principal domains. A comprehensive survey of metallic and nonmetallic nanomaterials (nanofillers), elucidating their efficacy as reinforcing agents in polymeric matrices. Emphasis is placed on the methodical design and engineering principles governing the development of functional nanocomposites. Additionally, the review provides an exhaustive examination of recent noteworthy advancements in industrial, environmental, biomedical, and clinical applications within the realms of nanocomposite materials. Finally, the review concludes by highlighting the ongoing challenges facing nanocomposites in a wide range of applications.

Remodeling of tumour microenvironment: strategies to overcome therapeutic resistance and innovate immunoengineering in triple-negative breast cancer

Triple-negative breast cancer (TNBC) stands as the most complex and daunting subtype of breast cancer affecting women globally. Regrettably, treatment options for TNBC remain limited due to its clinical complexity. However, immunotherapy has emerged as a promising avenue, showing success in developing effective therapies for advanced cases and improving patient outcomes. Improving TNBC treatments involves reducing side effects, minimizing systemic toxicity, and enhancing efficacy. Unlike traditional cancer immunotherapy, engineered nonmaterial's can precisely target TNBC, facilitating immune cell access, improving antigen presentation, and triggering lasting immune responses. Nanocarriers with enhanced sensitivity and specificity, specific cellular absorption, and low toxicity are gaining attention. Nanotechnology-driven immunoengineering strategies focus on targeted delivery systems using multifunctional molecules for precise tracking, diagnosis, and therapy in TNBC. This study delves into TNBC's tumour microenvironment (TME) remodeling, therapeutic resistance, and immunoengineering strategies using nanotechnology.

Scientific Insights into the Quantum Dots (QDs)-Based Electrochemical Sensors for State-of-the-Art Applications

Size-dependent optical and electronic properties are unique characteristics of quantum dots (QDs). A significant advantage is the quantum confinement effect that allows their precise tuning to achieve required characteristics and behavior for the targeted applications. Regarding the aforementioned factors, QDs-based sensors have exhibited dramatic potential for the diverse and advanced applications. For example, QDs-based devices have been potentially utilized for bioimaging, drug delivery, cancer therapy, and environmental remediation. In recent years, use of QDs-based electrochemical sensors have been further extended in other areas like gas sensing, metal ion detection, monitoring of organic pollutants, and detection of radioactive isotopes. Objective of this study is to rationalize the QDs-based electrochemical sensors for state-of-the-art applications. This review article comprehensively illustrates the importance of aforementioned devices along with sources from which QDs devices have been formulated and fabricated. Other distinct features of QDs devices are associated with their extremely high active surfaces, inherent ability of reproducibility, sensitivity, and selectivity for the targeted analyte detection. In this review, major categories of QD materials along with justification of their key roles in electrochemical devices have been demonstrated and discussed. All categories have been evaluated with special emphasis on the advantages and drawbacks/challenges associated with QD materials. However, in the interests of readers and researchers, recent improvements also have been included and discussed. On the evaluation, it has been concluded that despite significant challenges, QDs-based electrochemical sensors exhibit excellent performances for state-of-the-art and targeted applications.

Synthesis of nanohybrid consisting of taurine derived carbon dots and nanoceria for anticancer applications

Here, we first synthesized carbon dots (CDs) from taurine and then a nanohybrid with ceria (CeO2) nanoparticles using thermal decomposition method for checking their antineoplastic efficacy against human triple negative mammary carcinoma cells, MDA-MB-231. The in vitro study demonstrated significant dose-dependent antineoplastic activity of the nanohybrids within a range of concentration from 10 to 50 μg/mL after 48 h of treatment. The cellular morphology analysis clearly depicted substantial amount of cell death which seems to stem from increased intracellular reactive oxygen species (ROS) production. However, the maximum anticancer activity of the nanohybrid as compared to bare CDs and CeO2 is supposed to be due to the combined anticancer effect of both CDs and CeO2 (a well-established antitumor agent). Further we have performed molecular docking study to reveal the anticancer mechanism of CDs which exhibited high binding capacity towards several proapoptotic and antiapoptotic protein molecules. The binding affinity values were found to be - 8.7 kcal/mol, - 7.9 kcal/mol, - 9.6 kcal/mol, - 9.5 kcal/mol, - 12 kcal/mol and - 11.1 kcal/mol for BAD, BCl-2, p53, Caspase-8, Caspase-9 and Caspase-3 respectively. Taken together, our synthesized CDs-CeO2 nanohybrid could be thought as a potential anticarcinogenic option in the field of breast cancer therapeutics.

Citrus Medica-derived Fluorescent Carbon Dots for the Imaging of Vigna Radiate Root Cells

Bio-imaging is a crucial tool for researchers in the fields of cell biology and developmental biomedical sector. Among the various available imaging techniques, fluorescence based imaging stands out due to its high sensitivity and specificity. However, traditional fluorescent materials used in biological imaging often suffer from issues such as photostability and biocompatibility. Moreover, plant tissues contain compounds that cause autofluorescence and light scattering, which can hinder fluorescence microscopy effectiveness. This study explores the development of fluorescent carbon dots (Cm-CDs) synthesized from Citrus medica fruit extract for the fluorescence imaging of Vigna radiata root cells. The successful synthesis of CDs with an average size of 6.7 nm is confirmed by Transmission Electron Microscopy (TEM). The X-ray diffraction (XRD) analysis and raman spectroscopy indicated that the obtained CDs are amorphous in nature. The presence of various functional groups on the surface of CDs were identified by Fourier transform infrared (FTIR) spectra. The optical characteristics of Cm-CDs were studied by UV-Visible spectroscopy and photoluminescence spectroscopy. Cm-CDs demonstrated strong excitation-dependent fluorescence, good solubility, and effective penetration in to the Vigna radiata root cells with multicolor luminescence, and addressed autofluorescence issues. Additionally, a comparative analysis determined the optimal concentration for high-resolution, multi-color root cell imaging, with Cm-CD2 (2.5 mg/ml) exhibiting the highest photoluminescence (PL) intensity. These findings highlight the potential of Cm-CDs in enhancing direct endocytosis and overcoming autofluorescence in plant cell imaging, offering promising advancements for cell biology research.

Efficient Dye Degradation and Antibacterial Activity of Carbon Dots/Chitosan-Doped La2O3 Nanorods: In Silico Molecular Docking Analysis

This work demonstrates the degradation of toxic RhB (rhodamine B) dye from polluted water in various pH environments. It assesses the antibacterial action of CDs (carbon dots)/CS (chitosan)-doped La₂O₃ (lanthanum oxide) NRs (nanorods). CS and CDs have been introduced as dopants to modify the characteristics of La₂O₃ to achieve efficient outcomes. The influence of doping on the structural, morphological, optical, and elemental properties of synthesized La₂O₃ NRs was investigated through a number of analytical techniques. The structural analysis of XRD revealed a hexagonal phase. The rod-like structure of pure La₂O₃ and reduction in the size of NRs upon doping were exhibited by TEM micrographs. From UV-vis spectroscopy, increased absorption upon doping and introduction of redshift that led to reduced bandgap energy were observed. The FTIR spectra indicate the presence of functional groups of pure and integrated samples. The catalytic activity of specimens in basic medium toward dye showed excellent results (94.57%). The inhibition zone of diameter 4.15 mm was evaluated by 6 mL of CDs/CS-doped La₂O₃ NRs against Escherichia coli once the surface area increased by dopants. In silico experiments were performed for enoyl-[acyl-carrier-protein] reductase (FabI) and DNA gyrase enzymes to assess the potency of CS-doped La₂O₃ and CDs/CS-doped La₂O₃ as their inhibitors and to justify their possible mechanism of action.

Carbon Dots for the Treatment of Inflammatory Diseases: An Appraisal of In Vitro and In Vivo Studies

In recent decades, several studies demonstrating various applications of carbon dots (C-dots), including metal sensing, bioimaging, pH sensing, and antimicrobial activities, have been published. Recent developments have shifted this trend toward biomedical applications that target various biomarkers relevant to chronic diseases. However, relevant developments and research results regarding the anti-inflammatory properties of C-dots against inflammation-associated diseases have not been systematically reviewed. Hence, this review discusses the anti-inflammatory effects of C-dots in in vivo and in vitro models of LPS-induced inflammation, gout, cartilage tissue engineering, drug-induced inflammation, spinal cord injury, wound healing, liver diseases, stomach cancer, gastric ulcers, acute kidney and lung injury, psoriasis, fever or hypothermia, and bone tissue regeneration. The compiled studies demonstrate the promising potential of C-dots as anti-inflammatory agents for the development of new drugs.

Green Synthesis of Highly Fluorescent Carbon Dots from Bovine Serum Albumin for Linezolid Drug Delivery as Potential Wound Healing Biomaterial: Bio-Synergistic Approach, Antibacterial Activity, and In Vitro and Ex Vivo Evaluation

A simple and green approach was developed to produce novel highly fluorescent bovine serum albumin carbon dots (BCDs) via facile one-step hydrothermal treatment, using bovine serum albumin as a precursor carbon source. Inherent blue photoluminescence of the synthesized BCDs provided a maximum photostability of 90.5 ± 1.2% and was characterized via TEM, FT-IR, XPS, XRD, UV-visible, and zeta potential analyses. By virtue of their extremely small size, intrinsic optical and photoluminescence properties, superior photostability, and useful non-covalent interactions with the synthetic oxazolidinone antibiotic linezolid (LNZ), BCDs were investigated as fluorescent nano-biocarriers for LNZ drug delivery. The release profile of LNZ from the drug delivery system (LNZ-BCDs) revealed a distinct biphasic release, which is beneficial for mollifying the lethal incidents associated with wound infection. The effective wound healing performance of the developed LNZ-BCDs were evaluated through various in vitro and ex vivo assays such as MTT, ex vivo hemolysis, in vitro antibacterial activity, in vitro skin-related enzyme inhibition, and scratch wound healing assays. The examination of LNZ-BCDs as an efficient wound healing biomaterial illustrated excellent biocompatibility and low cytotoxicity against normal human skin fibroblast (HSF) cell line, indicating distinct antibacterial activity against the most common wound infectious pathogens including Staphylococcus aureus (ATCC^® 25922) and methicillin-resistant Staphylococcus aureus, robust anti-elastase, anti-collagenase, and anti-tyrosinase activities, and enhanced cell proliferation and migration effect. The obtained results confirmed the feasibility of using the newly designed fluorescent LNZ-BCDs nano-bioconjugate as a unique antibacterial biomaterial for effective wound healing and tissue regeneration. Besides, the greenly synthesized BCDs could be considered as a great potential substitute for toxic nanoparticles in biomedical applications due to their biocompatibility and intense fluorescence characteristics and in pharmaceutical industries as promising drug delivery nano-biocarriers for effective wound healing applications.

Recent Development of Nano-Carbon Material in Pharmaceutical Application: A Review

Carbon nanomaterials have attracted researchers in pharmaceutical applications due to their outstanding properties and flexible dimensional structures. Carbon nanomaterials (CNMs) have electrical properties, high thermal surface area, and high cellular internalization, making them suitable for drug and gene delivery, antioxidants, bioimaging, biosensing, and tissue engineering applications. There are various types of carbon nanomaterials including graphene, carbon nanotubes, fullerenes, nanodiamond, quantum dots and many more that have interesting applications in the future. The functionalization of the carbon nanomaterial surface could modify its chemical and physical properties, as well as improve drug loading capacity, biocompatibility, suppress immune response and have the ability to direct drug delivery to the targeted site. Carbon nanomaterials could also be fabricated into composites with proteins and drugs to reduce toxicity and increase effectiveness in the pharmaceutical field. Thus, carbon nanomaterials are very effective for applications in pharmaceutical or biomedical systems. This review will demonstrate the extraordinary properties of nanocarbon materials that can be used in pharmaceutical applications.

One-step solvent-free synthesis of carbon dot-based layered composites exhibiting color-tunable photoluminescence

We here report a practical and green approach to the development of luminescent composites through in situ solvent-free formation of carbon dots on layered inorganic compounds. The composites exhibit higher solid-state photoluminescence than those prepared by mixing of synthesized carbon dots and layered clay minerals. Tuning of the emission color of the composites has also been achieved by the addition of small molecules into phloroglucinol as starting materials for carbonization. The carbon dots synthesized in clay compounds in the solvent-free conditions are well-dispersed to obtain homogeneous composites. Furthermore, we have demonstrated that highly luminescent carbon dots are formed by carbonization in the presence of layered inorganic compounds. The one-step solvent-free approach presented in this work may allow not only facile, economical, and sustainable production of nanostructured carbon dot-based composites but also improvement of their luminescence properties.

Smartphone-integrated colorimetric sensor array-based reader system and fluorometric detection of dopamine in male and female geriatric plasma by bluish-green fluorescent carbon quantum dots

A simple, cost-effective system was developed for dopamine (DA) detection using green synthesized 1-6 ​nm honey-based carbon quantum dots (H-CQDs) exhibiting bluish green fluorescence. The H-CQDs exhibited emission at 445 ​nm, with a quantum yield of ∼44%. The H-CQDs were used as a probe for electron transfer based DA detection and changes in H-CQD color in the presence of DA. The H-CQDs were formed with polar functional groups and were highly soluble in aqueous media. In the fluorometric mode, the proposed system demonstrated high specificity toward DA and effective limit of detection (LOD) values of 6, 8.5, and 8 ​nM in deionized (DI) water, male geriatric plasma, and female geriatric plasma, respectively, in the linear range 100 ​nM-1000 μM. In the colorimetric mode, the color changed within 5 ​min, and the LOD was 163 ​μM. A colorimetric sensor array system was used to precisely detect DA with a smartphone-integrated platform using an in house built imaging application and an analyzer app. Additionally, no additives were required, and the H-CQDs were not functionalized. More importantly, the H-CQDs were morphologically and analytically characterized before and after DA detection. Because the sensor array-based system allows high specificity DA detection in both DI water and geriatric plasma, it will play an important role in biomedical applications.

A glutathione-responsive polyphenol - Constructed nanodevice for double roles in apoptosis and ferroptosis

Combination chemotherapy regimens have been put forward to achieve a synergistic effect and reduce drug doses for the clinical applications of cancer treatment. One of the principal approaches for killing cancer cells involves triggering apoptotic cell death with anti-cancer drugs. Nevertheless, the efficacy of apoptosis induction in tumors is often restricted on account of intrinsic or acquired resistance of cancer cells to apoptosis. Ferroptosis, which involves reactive oxygen species (ROS), is another way to regulate cell death. Doxorubicin (DOX), a commonly used chemotherapeutic agent, can enter the nucleus and destroy tumor cells while also affecting mitochondria by producing semiquinone radicals. Therefore, a drug system combining ferroptosis and apoptosis, bridged by DOX-induced ROS, was proposed to be designed. Herein, we employed a facile and effective self-assembly method to prepare DOX-loaded nanocomplexes by DOX, Pluronic F-68, tannic acid (TA), and iron ions. TA and iron ions could not only improve the stability of nanocarrier but also facilitate achieving a ferroptotic effect. As a result, DOX@F-68/TA/Fe³⁺ nanocomplexes showed a strong pro-apoptotic effect as well as an increase in intracellular oxidative stress. The improved oxidative stress further resulted in the ferroptosis of tumor cells. In vivo experiments demonstrated that DOX@F-68/TA/Fe³⁺ efficiently targeted the tumor following intravenous injection and successfully inhibited tumor development.

Applications of natural product-derived carbon dots in cancer biology

Natural products have contributed conspicuously to the development of innovative nanomedicines. Hence, the interface between nanomaterial science and plant natural products may bestow comprehensive diagnostic and therapeutic strategies for tackling diseases such as cancer and neurological disorders. Natural product-derived carbon dots (NPdCDs) have revealed noteworthy attributes in the fields of cancer theranostics, microbial imaging, drug sensing and drug delivery. As plants consist of a cocktail of bioactive phytomolecules, the NPdCDs can be anticipated to have medicinal properties, biocompatibility, photo-stability and easy functionalization. NPdCDs have wide-ranging applications. The primary objective of this review is to comment on recent developments in the use of NPdCDs, with special reference to their application in cancer biology. The future of the use of NPdCDs has also been considered.

Cytotoxicity and Bioimaging Study for NHDF and HeLa Cell Lines by Using Graphene Quantum Pins

Herein, we report the synthesis of an interesting graphene quantum material called "graphene quantum pins (GQPs)". Morphological analysis revealed the interesting pin shape (width: ~10 nm, length: 50-100 nm) and spectral analysis elucidated the surface functional groups, structural features, energy levels, and photoluminescence properties (blue emission under 365 nm). The difference between the GQPs and graphene quantum dos (GQDs) isolated from the same reaction mixture as regards to their morphological, structural, and photoluminescence properties are also discussed along with the suggestion of a growth mechanism. Cytotoxicity and cellular responses including changes in biophysical and biomechanical properties were evaluated for possible biomedical applications of GQPs. The studies demonstrated the biocompatibility of GQPs even at a high concentration of 512 μg/mL. Our results suggest GQPs can be used as a potential bio-imaging agent with desired photoluminescence property and low cytotoxicity.

Natural carbon-based quantum dots and their applications in drug delivery: A review

Natural carbon based quantum dots (NCDs) are an emerging class of nanomaterials in the carbon family. NCDs have gained immense acclamation among researchers because of their abundance, eco-friendly nature, aqueous solubility, the diverse functionality and biocompatibility when compared to other conventional carbon quantum dots (CDs).The presence of different functional groups on the surface of NCDs such as thiol, carboxyl, hydroxyl, etc., provides improved quantum yield, physicochemical and optical properties which promote bioimaging, sensing, and drug delivery. This review provides comprehensive knowledge about NCDs for drug delivery applications by outlining the source and rationale behind NCDs, different routes of synthesis of NCDs and the merits of adopting each method. Detailed information regarding the mechanism behind the optical properties, toxicological profile including biosafety and biodistribution of NCDs that are favourable for drug delivery are discussed. The drug delivery applications of NCDs particularly as sensing and real-time tracing probe, antimicrobial, anticancer, neurodegenerative agents are reviewed. The clinical aspects of NCDs are also reviewed as an initiative to strengthen the case of NCDs as potent drug delivery agents.