Carbon Dots as Promising Tools for Cancer Diagnosis and Therapy

Renal clearable sucrose carbon dots for doxorubicin delivery to treat renal carcinoma

Renal Cell Carcinoma (RCC) poses challenges for conventional treatment methods, but recent advancements indicate the potential of nanoparticles (NPs) in enhancing chemotherapy efficacy. This study focuses on developing non-toxic NPs from sucrose and l-serine via hydrothermal synthesis to produce Sucrose Carbon Dots (Suc CDs), designed for renal clearance to deliver hydrophilic drugs for the treatment of RCC. Suc CDs with a size of 4 nm exhibit high fluorescence with a fluorescence quantum yield of 58% and high drug loading capacity without toxicity to normal cell lines (renal tubular cells). Under in vitro conditions, Suc CDs alone are non-toxic, while Suc CDs with DOX display improved anticancer effects on Renca cells (cancer cell line). Under in vivo conditions, Suc CDs loaded with DOX outperform DOX alone with reduced toxicity to normal cells. Biodistribution study of Suc CDs revealed prolonged tumour site accumulation. This research demonstrates that renal clearable Suc CDs loaded with DOX exhibit superior anti-cancer activity, and are free of side effects, suggesting promising therapeutic potential for human RCC.

Potential of Carbon Nanodots (CNDs) in Cancer Treatment

Carbon Nanodots (CNDs) are characterized by their nanoscale size (<10 nm), biocompatibility, stability, fluorescence, and photoluminescence, making them a promising candidate for cancer therapy. The difference in the methods of synthesis of CNDs, whether top-down or bottom-up, affects the formation, visual, and surface characteristics of CNDs, which are crucial for their biomedical and pharmaceutical applications. The urgent need for innovative therapeutic strategies from CNDs is due to the limitations and barriers posed by conventional therapies including drug resistance and cytotoxicity. Nano-loaded chemotherapy treatments are highly effective and can enhance the solubility and targeted delivery of chemotherapeutic agents, generate reactive oxygen species (ROS) to induce cancer cell cytotoxicity, and regulate intracellular signaling pathways. Their ability to be designed for cellular uptake and exact intracellular localization further improves their therapeutic potential. In addition to working on drug delivery, CNDs are highlighted for their dual functionality in imaging and therapy, which allows real-time observing of treatment efficacy. Despite the development of these treatments and the promising results for the future, challenges still exist in cancer treatment.

Targeted bio-imaging in discriminating normal and cancerous cells using dual-doped carbon dots derived from Dahlia pinnata flower extract

This research delves into utilizing dual-doped (N & S) carbon dots (DDCDs) sourced from Dahlia pinnata flower extract for targeted bio-imaging, aiming to differentiate between normal and cancerous cells. The synthesized DDCDs, incorporating nitrogen and sulfur, exhibited unique optical, structural, and morphological properties with an average size of about 3.25 nm. These DDCDs demonstrate strong fluorescence and display excitation-dependent emission behavior, as confirmed by the results of photoluminescence spectroscopy. Folic acid conjugation with DDCDs enhances their specificity towards cancer cells expressing the folate receptor. Through comprehensive characterization, the study demonstrates the successful synthesis and functionalization of these DDCDs. Even at a concentration of 200 µg/ml, these DDCDs demonstrated low cytotoxicity. In vitro experiments on both normal and cancer cell lines reveal distinct fluorescence responses, showcasing the potential of these bio-compatible DDCDs for precise bio-imaging in cancer diagnostics. This work opens avenues for utilizing natural sources in nanomaterial synthesis for biomedical applications, contributing to the advancement of targeted cellular imaging technologies.

Applications of Green Carbon Dots in Personalized Diagnostics for Precision Medicine

Green carbon dots (GCDs) have emerged as a revolutionary tool in precision medicine, offering transformative capabilities for personalized diagnostics and therapeutic strategies. Their unique optical and biocompatible properties make them ideal for non-invasive imaging, real-time monitoring, and integration with genomics, proteomics, and bioinformatics, enabling accurate diagnosis and tailored treatments based on patients' genetic and molecular profiles. This study explores the potential of GCDs in advancing individualized patient care by examining their applications in precision medicine. It evaluates their utility in non-invasive diagnostic imaging, targeted therapy delivery, and the formulation of personalized treatment plans, emphasizing their interaction with advanced genomic, proteomic, and bioinformatics platforms. GCDs demonstrated exceptional versatility in enabling precise diagnostics and delivering targeted therapies. Their integration with cutting-edge technologies showed significant promise in crafting personalized treatment strategies, enhancing their functionality and effectiveness in real-time monitoring and patient-specific applications. The findings underscore the pivotal role of GCDs in reshaping healthcare by advancing precision medicine and improving patient outcomes. The ongoing development and integration of GCDs with emerging technologies promise to further enhance their capabilities, paving the way for more effective, individualized medical care.

DON encapsulated carbon dot-vesicle conjugate in therapeutic intervention of lung adenocarcinoma by dual targeting of CD44 and SLC1A5

Lung adenocarcinoma, recognized as one of the most formidable malignancies with a dismal prognosis and low survival rates, poses a significant challenge in its treatment. This article delineates the design and development of a carbon dot-vesicle conjugate (HACD-TMAV) for efficient cytotoxicity towards lung cancer cells by target selective delivery of the glutamine inhibitor 6-diazo-5-oxo-L-norleucine (DON) within CD44-enriched A549 cancer cells. HACD-TMAV is composed of hyaluronic acid-based carbon dots (HACDs) and trimesic acid-based vesicles (TMAV), which are bound via electrostatic interactions. TMAVs are formed by positively charged trimesic acid-based amphiphiles through H-type aggregation in water. HACDs were synthesized through a one-step hydrothermal route. The blue-emitting HACD-TMAV conjugate demonstrated selective bioimaging in CD44-overexpressed A549 lung cancer cells due to specific ligand-receptor interactions between HA and CD44. HACD-TMAV exhibited notably improved DON loading efficiency compared to individual nano-vehicles. HACD-TMAV-DON exhibited remarkable (∼6.0-fold higher) cytotoxicity against CD44-overexpressing A549 cells compared to CD44- HepG2 cells and HEK 293 normal cells. Also, DON-loaded HACD-TMAV showed ∼2.0-fold higher cytotoxicity against A549 cells compared to individual carriers and ∼4.5-fold higher cytotoxicity than by DON. Furthermore, HACD-TMAV-DON induced a ∼3.5-fold reduction in the size of 3D tumor spheroids of A549 cells. The enhanced anticancer effectiveness was attributed to starvation of the A549 cells of glutamine by dual targeting of glutamine metabolism and solute linked carrier family 1 member A5 (SLC1A5) through HA-linked CD44-mediated targeted delivery of DON. This led to over-production of reactive oxygen species (ROS) that induced apoptosis of cancer cells through downregulation of the PI3K/AKT/mTOR signaling cascade.

Carbon Dot Micelles Synthesized from Leek Seeds in Applications for Cobalt (II) Sensing, Metal Ion Removal, and Cancer Therapy

Popular photoluminescent (PL) nanomaterials, such as carbon dots, have attracted substantial attention from scientists due to their photophysical properties, biocompatibility, low cost, and diverse applicability. Carbon dots have been used in sensors, cell imaging, and cancer therapy. Leek seeds with anticancer, antimicrobial, and antioxidant functions serve as traditional Chinese medicine. However, leek seeds have not been studied as a precursor of carbon dots. In this study, leek seeds underwent a supercritical fluid extraction process. Leek seed extract was obtained and then carbonized using a dry heating method, followed by hydrolysis to form carbon dot micelles (CD-micelles). CD-micelles exhibited analyte-induced PL quenching against Co2+ through the static quenching mechanism, with the formation of self-assembled Co2+-CD-micelle sphere particles. In addition, CD-micelles extracted metal ion through liquid-liquid extraction, with removal efficiencies of >90% for Pb2+, Al3+, Fe3+, Cr3+, Pd2+, and Au3+. Moreover, CD-micelles exhibited ABTS•+ radical scavenging ability and cytotoxicity for cisplatin-resistant lung cancer cells. CD-micelles killed cisplatin-resistant small-cell lung cancer cells in a dose-dependent manner with a cancer cell survival rate down to 12.8 ± 4.2%, with a similar treatment function to that of cisplatin. Consequently, CD-micelles functionalized as novel antioxidants show great potential as anticancer nanodrugs in cancer treatment.

A new herbal extract carbon nanodot nanomedicine for anti-renal cell carcinoma through the PI3K/AKT signaling pathway

New Re carbon nanodots with narrow size distribution, good water solubility and high cell membrane permeability were prepared from a herbal extract. They exhibited high inhibitory effects on renal cancer A498 cells and renal cell carcinoma. They could stimulate the production of ROS, induce mitochondrial dysfunction, and accelerate the release of intracellular calcium ions in the A498 cells. Transcriptomic tests were performed on A498 cells after administration, and the results were analyzed by qPCR and immunofluorescence. The results suggested that the Re carbon nanodots could downregulate the abnormally activated PI3K/AKT signaling pathway and perform cell cycle arrest in the S phase along with the inhibition of cell proliferation. Finally, in conjunction with the abnormal mitochondrial function, the Re carbon nanodots could ultimately promote the apoptosis of the A498 cells. In vivo tumor-bearing mouse experiments further showed that the Re carbon nanodots had a strong inhibitory effect on xenograft kidney cancer tumors. The prepared Re carbon nanodots have good anti-renal cancer A498 cell and renal cell carcinoma bioactivity and are expected to be a potential drug for the treatment of kidney cancer with low toxicity and high safety.

8-Anilino-1-naphthalenesulfonate-Conjugated Carbon-Coated Ferrite Nanodots for Fluoromagnetic Imaging, Smart Drug Delivery, and Biomolecular Sensing

BACKGROUND

Superparamagnetic properties and excitation independence have been incorporated into carbon-decorated manganese ferrite nanodots (MnFe@C) to introduce an economical and safer multimodal agent for use in both T1-T2 MRI and fluorescence-based imaging to replace the conventional highly toxic heavy metal contrast agents.

METHODS

The surface conjugation of 8-anilino-1-naphthalenesulfonate (ANS) to MnFe@C nanodots (ANS-MnFe@C) enhances both longitudinal and transverse MRI relaxation, improves fluorescence for optical imaging, and increases protein detection sensitivity, showing higher multimodal efficacy in terms of molar relaxivity, radiant efficiencies, and fluorescence sensitivity compared to MnFe@C.

RESULTS

The band gap energy was determined using Tauc's equation to be 3.32 eV, while a 72% quantum yield demonstrated that ANS-MnFe@C was highly fluorescent, with the linear range and association constant calculated using the Stern-Volmer relation. The synthesized ANS-MnFe@C demonstrated excellent selectivity and sensitivity for bovine serum albumin (BSA), with a nanomolar detection limit of 367.09 nM and a broad linear range from 0.015 to 0.225 mM.

CONCLUSIONS

In conclusion, ANS-MnFe@C holds ease of fabrication, good biocompatibility, as assessed in A375 cells, and an effective pH-sensitive doxorubicin release profile to establish anticancer activity in lung cancer cell line (A549), highlighting its potential as an affordable therapeutic agent for multimodal imaging, drug delivery, and protein sensing.

Polymeric nanoparticles loaded with vincristine and carbon dots for hepatocellular carcinoma therapy and imaging

Chemotherapy for hepatoblastoma is limited by organ toxicity and poor outcomes, prompting the search for new, more effective treatments with minimal side effects. Vincristine sulfate, a potent chemotherapeutic, faces challenges due to P-glycoprotein-mediated resistance and its systemic toxicity. Nanoparticles offer a promising solution by improving pharmacokinetics, targeting tumor cells, thus reducing side effects. Moreover, the use of fluorescent nanomaterials is emerging in biomedical applications such as bioimaging, detection and therapies. This study describes a promising delivery system utilizing carbon dots encapsulated with vincristine in biodegradable polycaprolactone nanoparticles via a double emulsion technique. The fine characterization of these nanoparticles showed that they are spherical, uniformly sized with around 200 nm and exhibit excellent colloidal stability. Moreover, the release profile showed prolonged release for both vincristine and carbon dots. In vitro cell viability studies revealed enhanced cancer cell inhibition for the encapsulated drug compared to the vincristine solution. The uptake study indicated clear fluorescence for carbon dots solution and vincristine and carbon dots loaded nanoparticles upon excitation. Additionally, studies on primary mouse hepatocytes demonstrated higher fluorescence intensity in treatment groups. These results suggest that vincristine and carbon dots loaded nanoparticles are effective, target-specific carriers for liver cancer treatment. Furthermore, the carbon dots were not cytotoxic, highlighting their potential in bioimaging and cancer cell studies.

Unveiling the multifaceted applications of pamoic acid carbon dots (PACDs) in sensing and oncology

In our research we explore the world of PACDs, carbon dots synthesized from pamoic acid through a single step pyrolysis method. Our findings reveal that PACDs have capabilities of serving as sensitive and selective sensors in both colorimetric and fluorescent modes. They are particularly effective, at colorimetrically and fluorometrically detecting ferric ions and can also act as fluorometric sensors for pH. When ferric ions are introduced an interesting transformation occurs. A noticeable change in color unfolds before our eyes, under 365 nm UV light the fluorescence shifts from green to blue while in daylight it changes from a yellow to a deep ink blue. Notably these detection techniques can precisely measure ferric ions within concentrations ranging from 5 µM to 80 µM with a detection limit of 0.1 µM for fluorescence response. Additionally, they can detect ferric ions colorimetrically within the range of 5 µM to 45 µM with a detection limit of 3.8 µM. Furthermore, the PACDs exhibit a capability to adapt to different pH levels. In alkaline environments with a pH range between 8 and 11 the fluorescence signal demonstrates a response that directly correlates with pH levels and slightly shifts its position. In contrast under acidic conditions a noticeable shift, towards blue is observed in the fluorescence signal leading to a change in color from green to blue when exposed to UV light. This shift persists as the fluorescence signal directly correlates with decreasing pH levels in settings. Apart from their proficiency in ferric ion detection and pH monitoring, the PACDs also demonstrate potential in cancer research. Through an assessment using the MTT assay it was discovered that the PACDs exhibit cytotoxic effects against five different cancer cell lines; HCT 116, MDA MB 231, Hep3B, MCF 7 and HeLa. The findings are promising as the PACDs show IC50 values of 12.5 µg/ml 6.25 µg/ml 25 µg/ml 50 µg/ml and 100 µg/ml for these cell lines. This research highlights the versatility and potential of PACDs as a tool, in both sensing applications and oncology research.

Safety Evaluation of Carbon Dots in UM-UC-5 and A549 Cells for Biomedical Applications

BACKGROUNG

The rising complexity and associated side effects of cancer treatments highlight the need for safer and more effective therapeutic agents. Carbon-based nanomaterials such as CDs have been gaining prominence for their unique characteristics, opening avenues for diverse applications such as fluorescence imaging, drug and gene transport, controlled drug delivery, medical diagnosis, and biosensing. Despite promising advancements in research, it remains imperative to scrutinize the properties and potential cytotoxicity of newly developed CDs, ensuring their viability for these applications.

METHODS

We synthesized four N-doped CDs through a hydrothermal method. Cell viability assays were conducted on A549 and UM-UC-5 cancer cells at a range of concentrations and incubation times, both individually and with the chemotherapeutic agent 5-fluorouracil (5-FU).

RESULTS

The obtained results suggest that the newly developed CDs exhibit suitability for applications such as bioimaging, as no significant impact on cell viability was observed for CDs alone.

Solvent-Controlled Strategy for Color-Tunable Fluorescence Carbon Dots and Their Application in Light-Emitting Diodes

Carbon dots (CDs) offer tremendous advantages in the fields such as bioimaging, sensing, biomedicine, catalysis, information encryption, and optoelectronics. However, the inherent challenge is synthesizing CDs with a full-spectrum emission, as most CDs typically produce only blue or green emissions, which severely hinder further investigation into their fluorescence mechanism and restrict their broader applications in light-emitting diodes (LEDs). In this work, we reported a solvent-controlled strategy for the preparation of multicolor CDs with blue, yellow, and red emissions, using o-phenylenediamine (oPD) and ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BmimPF6) as precursors. The detailed characterizations proved that a solvent with a lower boiling point and lower solubility of precursors resulted in a higher degree of dehydration and carbonization process, thereby increasing carbon cores with sp2-conjugated domains and nitrogen doping and further reducing the bandgap energies, causing a significant redshift emission from blue to red. The underlying fluorescence mechanism of the prepared multicolor CDs was contributed to the surface state. Eventually, blue-, yellow-, and red-emitting CDs based on poly(vinyl alcohol) (PVA) films and colorful LEDs devices were fabricated by dispersing the as-synthesized CDs into a PVA solution. The proposed solvent-controlled strategy for multicolor CDs preparation will be helpful for fully utilizing the advantages of CDs and expanding their applications.

Polylysine-modified near-infrared-emitting carbon dots assemblies: Amplification of tumor accumulation for enhanced tumor photothermal therapy

A key challenge to enhance the therapeutic outcome of photothermal therapy (PTT) is to improve the efficiency of passive targeted accumulation of photothermal agents at tumor sites. Carbon dots (CDs) are an ideal choice for application as photothermal agents because of their advantages such as adjustable fluorescence, high photothermal conversion efficiency, and excellent biocompatibility. Here, we synthesized polylysine-modified near-infrared (NIR)-emitting CDs assemblies (plys-CDs) through post-solvothermal reaction of NIR-emitting CDs with polylysine. The encapsulated structure of plys-CDs was confirmed by determining morphological, chemical, and luminescent properties. The particle size of CDs increased to approximately 40 ± 8 nm after polylysine modification and was within the size range appropriate for achieving superior enhanced permeability and retention effect. Plys-CDs maintained a high photothermal conversion efficiency of 54.9 %, coupled with increased tumor site accumulation, leading to a high efficacy in tumor PTT. Thus, plys-CDs have a great potential for application in photothermal ablation therapy of tumors.

Anticancer activity of quantum size carbon dots: opportunities and challenges

Research into the anticancer activity of quantum-sized carbon dots (CDs) has emerged as a promising avenue in cancer research. This CDs delves into the opportunities and challenges associated with harnessing the potential of these nanostructures for combating cancer. Quantum-sized carbon dots, owing to their unique physicochemical properties, exhibit distinct advantages as potential therapeutic agents. Opportunities lie in their tunable size, surface functionalization capabilities, and biocompatibility, enabling targeted drug delivery and imaging in cancer cells. However, we include challenges, a comprehensive understanding of the underlying mechanisms, potential toxicity concerns, and the optimization of synthesis methods for enhanced therapeutic efficacy. A succinct summary of the state of the research in this area is given in this review, emphasizing the exciting possibilities and ongoing challenges in utilizing quantum-sized carbon dots as a novel strategy for cancer treatment.

Biological Activity of Natural and Synthetic Peptides as Anticancer Agents

Cancer is one of the leading causes of morbidity and death worldwide, making it a serious global health concern. Chemotherapy, radiotherapy, and surgical treatment are the most used conventional therapeutic approaches, although they show several side effects that limit their effectiveness. For these reasons, the discovery of new effective alternative therapies still represents an enormous challenge for the treatment of tumour diseases. Recently, anticancer peptides (ACPs) have gained attention for cancer diagnosis and treatment. ACPs are small bioactive molecules which selectively induce cancer cell death through a variety of mechanisms such as apoptosis, membrane disruption, DNA damage, immunomodulation, as well as inhibition of angiogenesis, cell survival, and proliferation pathways. ACPs can also be employed for the targeted delivery of drugs into cancer cells. With over 1000 clinical trials using ACPs, their potential for application in cancer therapy seems promising. Peptides can also be utilized in conjunction with imaging agents and molecular imaging methods, such as MRI, PET, CT, and NIR, improving the detection and the classification of cancer, and monitoring the treatment response. In this review we will provide an overview of the biological activity of some natural and synthetic peptides for the treatment of the most common and malignant tumours affecting people around the world.

Recent Progress of Fluorescent Carbon Dots and Graphene Quantum Dots for Biosensors: Synthesis of Solution Methods and their Medical Applications

In the fields of health and biology, fluorescent nanomaterials have emerged as highly potential and very useful candidates for use in biosensor applications. These typical highly powerful nanomaterials are carbon dots (CDs) and graphene quantum dots (GQDs) among many other metallic nanomaterials. In the context of medical biosensors, this review article investigates the techniques of synthesis, and many uses of these nanomaterials, the obstacles that they face, and the potential for their future. We cover the significance of fluorescent nanomaterials, their use in the medical field, as well as the several techniques of synthesis for CDs and GQDs, including ultrasonication, hydrothermal, electrochemical method, surface modification, and solvothermal. In addition, we also discuss their biomedical applications, which include biomolecule detection, disease diagnosis and examine the obstacles and prospective possibilities for development of ultra-bright, ultra-sensitive, and selective biosensors for use in in-vivo research.Fluorescent carbon dots and graphene quantum dots is synthesized by using several types of raw material and methods. These Carbon dots and graphene quantum dots are used in the medical field includes detection of biomaterials, detection of cancer, virus and mutation in DNA.

The applications of carbon dots in oral health: A scoping review

OBJECTIVES

This scoping review aims to provide an overview of the research and potential applications of carbon dots (CDs) for oral health purposes.

DESIGN

Systematic literature searches were performed on PubMed and Web of Science databases (up to February 2023). Two co-authors selected the published works independently and extracted the data in accordance with the PRISMA statement. Studies with the application of CDs for oral health purposes were included.

RESULTS

Among 152 articles, 19 articles were finally selected. Eight studies investigated the anti-microbial effects of CDs against, for example, oral pathogens, eight studies explored the applicability of CDs in relation to oral cancer, and three studies investigated CDs in relation to cell differentiation and tissue regeneration in oral health. The studies showed the promising potential of CDs in oral health, particularly for inducing bacterial killing by increasing reactive oxygen species, killing oral cancer cells via photodynamic therapeutic effects, and inducing dental pulp and periodontal bone regeneration.

CONCLUSION

The findings show that CDs have the potential to be utilized in the future for various oral health purposes. Besides, these results underline the broad-spectrum applicability of CDs, crossing the borders of oral health.

Small Warriors of Nature: Novel Red Emissive Chlorophyllin Carbon Dots Harnessing Fenton-Fueled Ferroptosis for In Vitro and In Vivo Cancer Treatment

The appeal of carbon dots (CDs) has grown recently, due to their established biocompatibility, adjustable photoluminescence properties, and excellent water solubility. For the first time in the literature, copper chlorophyllin-based carbon dots (Chl-D CDs) are successfully synthesized. Chl-D CDs exhibit unique spectroscopic traits and are found to induce a Fenton-like reaction, augmenting photodynamic therapy (PDT) efficacies via ferroptotic and apoptotic pathways. To bolster the therapeutic impact of Chl-D CDs, a widely used cancer drug, temozolomide, is linked to their surface, yielding a synergistic effect with PDT and chemotherapy. Chl-D CDs' biocompatibility in immune cells and in vivo models showed great clinical potential.Proteomic analysis was conducted to understand Chl-D CDs' underlying cancer treatment mechanism. The study underscores the role of reactive oxygen species formation and pointed toward various oxidative stress modulators like aldolase A (ALDOA), aldolase C (ALDOC), aldehyde dehydrogenase 1B1 (ALDH1B1), transaldolase 1 (TALDO1), and transketolase (TKT), offering a deeper understanding of the Chl-D CDs' anticancer activity. Notably, the Chl-D CDs' capacity to trigger a Fenton-like reaction leads to enhanced PDT efficiencies through ferroptotic and apoptotic pathways. Hence, it is firmly believed that the inherent attributes of Chl-CDs can lead to a secure and efficient combined cancer therapy.

CARBON DOTS: Bioimaging and Anticancer Drug Delivery

Cancer, responsible for approximately 10 million lives annually, urgently requires innovative treatments, as well as solutions to mitigate the limitations of traditional chemotherapy, such as long-term adverse side effects and multidrug resistance. This review focuses on Carbon Dots (CDs), an emergent class of nanoparticles (NPs) with remarkable physicochemical and biological properties, and their burgeoning applications in bioimaging and as nanocarriers in drug delivery systems for cancer treatment. The review initiates with an overview of NPs as nanocarriers, followed by an in-depth look into the biological barriers that could affect their distribution, from barriers to administration, to intracellular trafficking. It further explores CDs' synthesis, including both bottom-up and top-down approaches, and their notable biocompatibility, supported by a selection of in vitro, in vivo, and ex vivo studies. Special attention is given to CDs' role in bioimaging, highlighting their optical properties. The discussion extends to their emerging significance as drug carriers, particularly in the delivery of doxorubicin and other anticancer agents, underscoring recent advancements and challenges in this field. Finally, we showcase examples of other promising bioapplications of CDs, emergent owing to the NPs flexible design. As research on CDs evolves, we envisage key challenges, as well as the potential of CD-based systems in bioimaging and cancer therapy.

Photochemical synthesis, characterization, and electrochemical sensing properties of CD-AuNP nanohybrids

Among the existing nanosystems used in electrochemical sensing, gold nanoparticles (AuNPs) have attracted considerable attention owing to their intriguing chemical and physical properties such as good electrical conductivity, high electrocatalytic activity, and high surface-to-volume ratio. However, despite these useful characteristics, there are some issues due to their instability in solution that can give rise to aggregation phenomena and the use of hazardous chemicals in the most common synthetic procedures. With an aim to find a solution to these issues, recently, we prepared and characterized carbon dots (CDs), from olive solid wastes, and employed them as reducing and capping agents in photo-activated AuNP synthesis, thus creating CD-Au nanohybrids. These nanomaterials appear extremely stable in aqueous solutions at room temperature, are contemporary, and have been obtained using CDs, which are exclusively based on non-toxic elements, with an additional advantage of being generated from an otherwise waste material. In this paper, the synthesis and characterization of CD-Au nanohybrids are described, and the electrochemical experiments for hydroquinone detection are discussed. The results indicate that CD-Au acts as an efficient material for sensing hydroquinone, matching a wide range of interests in science from industrial processes to environmental pollution.

Molecularly Targeted Lanthanide Nanoparticles for Cancer Theranostic Applications

Injectable colloidal solutions of lanthanide oxides (nanoparticles between 10 and 100 nm in size) have demonstrated high biocompatibility and no toxicity when the nanoparticulate units are functionalized with specific biomolecules that molecularly target various proteins in the tumor microenvironment. Among the proteins successfully targeted by functionalized lanthanide nanoparticles are folic receptors, fibroblast activation protein (FAP), gastrin-releasing peptide receptor (GRP-R), prostate-specific membrane antigen (PSMA), and integrins associated with tumor neovasculature. Lutetium, samarium, europium, holmium, and terbium, either as lanthanide oxide nanoparticles or as nanoparticles doped with lanthanide ions, have demonstrated their theranostic potential through their ability to generate molecular images by magnetic resonance, nuclear, optical, or computed tomography imaging. Likewise, photodynamic therapy, targeted radiotherapy (neutron-activated nanoparticles), drug delivery guidance, and image-guided tumor therapy are some examples of their potential therapeutic applications. This review provides an overview of cancer theranostics based on lanthanide nanoparticles coated with specific peptides, ligands, and proteins targeting the tumor microenvironment.

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.

Baicalin functionalized PEI-heparin carbon dots as cancer theranostic agent

The worldwide prevalence of cancer and its significantly rising risks with age have garnered the attention of nanotechnology for prompt detection and effective therapy with minimal or no adverse effects. In the current study, heparin (HP) polymer derived heteroatom (N, S-) co-doped CDs were synthesized using hydrothermal synthesis method to efficiently deliver natural anticancer compound baicalin (BA). Heparin carbon dots (HCDs) were passivated with polyethylenimine (PEI) to improve its fluorescence quantum yield. The surface passivation of CDs by polycationic PEI polymer not only facilitated loading of BA, but also played a crucial role in the pH-responsive drug delivery. The sustained release of BA (up to 80 %) in mildly acidic pH (5.5 and 6.5) conditions endorsed its drug delivery potential for cancer-specific microenvironments. BA-loaded PHCDs exhibited enhanced anticancer activity as compared to BA/PHCDs indicating the effectiveness of the nanoformulation, Furthermore, the flow cytometry analysis confirmed that BA-PHCDs treated cells were arrested in the G2/M phase of cell cycle and had a higher potential for apoptosis. Bioimaging study demonstrated the excellent cell penetration efficiency of PHCDs with complete cytoplasmic localization. All this evidence comprehensively demonstrates the potency of BA-loaded PHCDs as a nanotheranostic agent for cancer.

An insight into recent developments of copper, silver and gold carbon dots: cancer diagnostics and treatment

Cancer is one of the most fatal diseases globally, however, advancement in the field of nanoscience specifically novel nanomaterials with nano-targeting of cancer cell lines has revolutionized cancer diagnosis and therapy and has thus attracted the attention of researchers of related fields. Carbon Dots (CDs)-C-based nanomaterials-have emerged as highly favorable candidates for simultaneous bioimaging and therapy during cancer nano-theranostics due to their exclusive innate FL and theranostic characteristics exhibited in different preclinical results. Recently, different transition metal-doped CDs have enhanced the effectiveness of CDs manifold in biomedical applications with minimum toxicity. The use of group-11 (Cu, Ag and Au) with CDs in this direction have recently gained the attention of researchers because of their encouraging results. This review summarizes the current developments of group-11 (Cu, Ag and Au) CDs for early diagnosis and therapy of cancer including their nanocomposites, nanohybrids and heterostructures etc. All The manuscript highlights imaging applications (FL, photoacoustic, MRI etc.) and therapeutic applications (phototherapy, photodynamic, multimodal etc.) of Cu-, Ag- and Au-doped CDs reported as nanotheranostic agents for cancer treatment. Sources of CDs and metals alogwith applications to give a comparative analysis have been given in the tabulated form at the end of manuscript. Further, future prospects and challenges have also been discussed.

Metformin-Loaded Hyaluronic Acid-Derived Carbon Dots for Targeted Therapy against Hepatocellular Carcinoma by Glutamine Metabolic Reprogramming

Metabolic reprogramming is a significant hallmark of cancer that promotes chemoresistance by allowing tumor tissues to adapt to changes in the tumor microenvironment caused by anticancer therapies. Hepatocellular carcinoma (HCC), one of the most common types of primary tumors, is associated with recurrent metabolic reprogramming that maximizes cancer cell growth and proliferation. Herein, we developed metformin (MET)-loaded hyaluronic acid (HA)-derived carbon dots (HA-CD-MET) by a simple and green method with no involvement of any additives. HA-CD-MET was utilized for specifically binding the CD44 receptor overexpressed in HCC and induced glutamine metabolic rewiring to inhibit HCC cell proliferation. Exposure to HA-CD-MET resulted in ∼6.5-fold better anticancer efficacy against CD44+ Hep3B cells in comparison to CD44-, HepG2, and noncancerous HEK293 cells at a very low dose of 80 μg/mL. Moreover, treatment of three-dimensional (3D) tumor spheroid model of HCC (Hep3B) with HA-CD-MET resulted in ∼4.9-fold reduction in tumor size. This improved anticancer efficacy of HA-CD-MET was attributed to the inhibition of glutaminase-1 (GLS-1), a mitochondrial enzyme that hydrolyzes glutamine into glutamate as confirmed from immunofluorescence and immunoblotting experiments. Furthermore, treatment with HA-CD-MET resulted in downregulation of glucose transporter-1 (GLUT-1) in Hep3B cells. Consequently, cancer cells were starved from essential nutrients, glutamine, and glucose, leading to the enhancement in intracellular ROS generation. This increase in intracellular ROS accumulation activated AMP-activated protein kinase (AMPK) and inhibited AKT phosphorylation, leading to cancer cell apoptosis. Thus, this study offers the targeting of metabolic reprogramming by HA-CD-MET that opens up a promising strategy for therapeutic intervention in hepatocarcinoma.

Biomass derived green carbon dots for sensing applications of effective detection of metallic contaminants in the environment

The rapid consumption of metals and unorganized disposal have led to unprecedented increases in heavy metal ion concentrations in the ecosystem, which disrupts environmental homeostasis and results in agricultural biodiversity loss. Mitigation and remediation plans for heavy metal pollution are largely dependent on the discovery of cost-effective, biocompatible, specific, and robust detectors because conventional methods involve sophisticated electronics and sample preparation procedures. Carbon dots (CDs) have gained significant importance in sensing applications related to environmental sustainability. Fluorescence sensor applications have been enhanced by their distinctive spectral properties and the potential for developing efficient photonic devices. With the recent development of biomass-functionalized carbon dots, a wide spectrum of multivalent and bivalent transition metal ions responsible for water quality degradation can be detected with high efficiency and minimal toxicity. This review explores the various methods of manufacturing carbon dots and the biochemical mechanisms involved in metal detection using green carbon dots for sensing applications involving Cu (II), Fe (III), Hg (II), and Cr (VI) ions in aqueous systems. A detailed discussion of practical challenges and future recommendations is presented to identify feasible design routes.

Carbon dots and composite materials with excellent performances in cancer-targeted bioimaging and killing: a review

Carbon dots (CDs) are nanomaterials with excellent properties, including good biocompatibility, small size, ideal photoluminescence and surface modification, and are becoming one of the most attractive nanomaterials for the imaging, detection and treatment of tumors. Based on these advantages, CDs can be combined other materials to obtain composite particles with improved, even new, performance, mainly in photothermal and photodynamic therapies. This paper reviews the research progress of CDs and their composites in targeted tumor imaging, detection, diagnosis, drug delivery and tumor killing. It also discusses and proposes the challenges and perspectives of their future applications in these fields. This review provides ideas for future applications of novel CD-based materials in the diagnosis and treatment of cancer.

Synthesis and physicochemical characterization of carbon quantum dots produced from folic acid

The rising interest in carbon dots (c-dots) is driven by their remarkable potential in the field of biomedical applications. This is due to their distinctive and adjustable photoluminescence characteristics, outstanding physicochemical properties, excellent photostability, and biocompatibility. Herein, carbon dots were successfully produced via the heat synthesis method and characterization for physical and chemical properties using UV-Vis spectrophotometer, photoluminescence spectroscopy, Fourier Transform Infrared and Raman spectroscopy, Energy-dispersive X-ray analysis, and quantum yield. The resulting carbon dots exhibited a distinct blue fluorescence upon exposure to ultraviolet radiation with a 366 nm wavelength. The photoluminescence spectrum of carbon dots displayed a fluorescence peak around 470 nm when excited with a 325 nm wavelength. The synthesized carbon dots demonstrated thermal stability and maintained photoluminescence intensity under different pH conditions, including neutral and alkaline mediums, and good salt resistance ability. Raman spectroscopy confirmed the presence of structural defects within the carbon dots, which are associated with the presence of hybrid groups on their surface. Fourier-transform infrared analysis detected various carbon-bonded, nitrogen-bonded, and oxygen-bonded units. The quantum yield was around 8.9%. These findings from our experiments indicate that the manufactured carbon dots possess substantial promise for a wide range of applications within the biotechnology field.

Green synthesis of fluorescent carbon nanodots from sage leaves for selective anticancer activity on 2D liver cancer cells and 3D multicellular tumor spheroids

Carbon nanodots, a family of carbon-based nanomaterials, have been synthesized through different methods from various resources, affecting the properties of the resulting product and their application. Herein, carbon nanodots (CNDs) were synthesized with a green and simple hydrothermal method from sage leaves at 200 °C for 6 hours. The obtained CNDs are well dispersed in water with a negative surface charge (ζ-potential = -11 mV) and an average particle size of 3.6 nm. The synthesized CNDs showed concentration-dependent anticancer activity toward liver cancer (Hep3B) cell lines and decreased the viability of the cancer cells to 23% at the highest used concentration (250 μg ml-1 of CNDs). More interestingly, the cytotoxicity of the CNDs was tested in normal liver cell lines (LX2) revealed that the CNDs at all tested concentrations didn't affect their viability including at the highest concentration showing a viability of 86.7%. The cellular uptake mechanisms of CNDs were investigated and they are thought to be through energy-dependent endocytosis and also through passive diffusion. The main mechanisms of endocytosis were lipid and caveolae-mediated endocytosis. In addition, the CNDs have hindered the formation of 3D spheroids from the Hep3B hepatocellular carcinoma cell line. Hence, it would be concluded that the synthesized CNDs from sage are more highly selective to liver cancer cells than normal ones. The CNDs' cancer-killing ability would be referred to as the production of reactive oxygen species.

Effectively synthesized functional Si-doped carbon dots with the applications in tyrosinase detection and lysosomal imaging

There has been significant interest in the preparation and versatile applications of carbon dots (CDs) due to their immense potential value in sensors and imaging. In this work, silicon-doped green carbon dots (Si-CDs) with high quantum yield and rich epoxypropyl were effectively synthesized. Given the clinical diagnostic importance of abnormal levels of tyrosinase (TYR), sensitive detection of TYR is significant for clinical research. A fluorescence signal-off strategy with Si-CDs as probe was constructed to determine TYR based on the oxidation of dopamine by TYR. The detection ranges of this method were 0.01-1.5 and 10-30 U/mL with the detection limit of 0.0046 U/mL, the lower limit of quantification (LLOQ) was 0.01 U/mL, and TYR was successfully and accurately monitored in human serum. Additionally, due to the role of lysosomes in cellular regulatory processes, including TYR levels and fluorescence stability characteristics of Si-CDs in acidic conditions, it was envisaged to use Si-CDs as probe to establish real-time monitoring of lysosomes. According to fluorescence colocation analysis, Si-CDs had intrinsic lysosomal targeting ability to HepG2 and L-02 (with Pearson correlation coefficients were 0.90 and 0.91, respectively). The targeting of Si-CDs to lysosomes was due to the acidophilic effect of the epoxypropyl on its surface.

EGTA-Derived Carbon Dots with Bone-Targeting Ability: Target-Oriented Synthesis and Calcium Affinity

The bone-targeting mechanism of clinic bisphosphonate-type drugs, such as alendronate, risedronate, and ibandronate, relies on chelated calcium ions on the surface of the bone mineralized matrix for the treatment of osteoporosis. EGTA with aminocarboxyl chelating ligands can specifically chelate calcium ions. Inspired by the bone-targeting mechanism of bisphosphonates, we hypothesize that EGTA-derived carbon dots (EGTA-CDs) hold bone-targeting ability. For the target-oriented synthesis of EGTA-CDs and to endow CDs with bone targeting, we designed calcium ion chelating agents as precursors, including aminocarboxyl chelating agents (EGTA and EDTA) and bisphosphonate agents (ALN and HEDP) for the target-oriented synthesis of aminocarboxyl-derived CDs (EGTA-CDs and EDTA-CDs) and bisphosphonate-derived CDs (ALN-CDs and HEDP-CDs) with high synthetic yield. The synthetic yield of EGTA-CDs reached 87.6%. Aminocarboxyl-derived CDs and bisphosphonate-derived CDs retain the chelation ability of calcium ions and can specifically bind calcium ions. The chemical environment bone-targeting value coordination constant K and chelation sites of EGTA-CDs were 6.48 × 104 M-1 and 4.12, respectively. A novel method was established to demonstrate the bone-targeting capability of chelate-functionalized carbon dots using fluorescence quenching in a simulated bone trauma microenvironment. EGTA-CDs exhibit superior bone-targeting ability compared with other aminocarboxyl-derived CDs and bisphosphonate-derived CDs. EGTA-CDs display exceptional specificity toward calcium ions and better bone affinity than ALN-CDs, suggesting their potential as novel bone-targeting drugs. EGTA-CDs with strong calcium ion chelating ability have calcium ion affinity in simulated body fluid and bone-targeting ability in a simulated bone trauma microenvironment. These findings offer new avenues for the development of advanced bone-targeting strategies.

Boron-Doped Carbon Nanodots as a Theranostic Agent for Colon Cancer Stem Cells

Carbon nanodots have drawn a great deal of attention due to their green and expedient opportunities in biological and chemical sciences. Their high fluorescence capabilities and low toxicity for living cells and tissues make them excellent imaging agents. In addition, they have a fluorimetric response against inorganic and organic species. Boron-doped carbon nanodots (B-CDs) with high fluorescence yield were produced from phenylboronic acid and glutamine as boron and carbon sources, respectively, by a hydrothermal method. First, the effects of the temperature on their fluorescence yield and the structural characteristics of B-CDs were investigated. Second, their cytotoxicity and cell death and proliferation behaviors were examined. The cytotoxicity was evaluated by the MTT assay. The cellular properties were evaluated with the distribution of caspase 3, Ki67, lamin B1, P16, and cytochrome c after the indirect immunoperoxidase technique. After the MTT assay, 1:1 dilution of all applicants for 24 h was used in the study. After immunohistochemical analyses, the application of B-CDs synthesized at 230 °C did not change control cell (Vero) proliferation, and also apoptosis was not triggered. Colo 320 CD133+ and CD133- cell-triggered apoptosis and cellular senescence were found to be synthesis temperature dependent. In addition, Colo 320 CD133- cells were affected relatively more than CD133+ cells from B-CDs. While B-CDs did not affect the control cells, the colon cancer stem cells (Colo 320 CD133+) were affected in a time-dependent manner. Therefore, the use of the synthesized B-CD product may be an alternative method for controlling or eliminating cancer stem cells in the tumor tissue.

Current Advances in the Biomedical Applications of Quantum Dots: Promises and Challenges

Quantum dots (QDs) are a type of nanoparticle with exceptional photobleaching-resistant fluorescence. They are highly sought after for their potential use in various optical-based biomedical applications. However, there are still concerns regarding the use of quantum dots. As such, much effort has been invested into understanding the mechanisms behind the behaviors of QDs, so as to develop safer and more biocompatible quantum dots. In this mini-review, we provide an update on the recent advancements regarding the use of QDs in various biomedical applications. In addition, we also discuss# the current challenges and limitations in the use of QDs and propose a few areas of interest for future research.

Progress in drug delivery and diagnostic applications of carbon dots: a systematic review

Carbon dots (CDs), which have particle size of less than 10 nm, are carbon-based nanomaterials that are used in a wide range of applications in the area of novel drug delivery in cancer, ocular diseases, infectious diseases, and brain disorders. CDs are biocompatible, eco-friendly, easy to synthesize, and less toxic with excellent chemical inertness, which makes them very good nanocarrier system to deliver multi-functional drugs effectively. A huge number of researchers worldwide are working on CDs-based drug delivery systems to evaluate their versatility and efficacy in the field of pharmaceuticals. As a result, there is a tremendous increase in our understanding of the physicochemical properties, diagnostic and drug delivery aspects of CDs, which consequently has led us to design and develop CDs-based theranostic system for the treatment of multiple disorders. In this review, we aim to summarize the advances in application of CDs as nanocarrier including gene delivery, vaccine delivery and antiviral delivery, that has been carried out in the last 5 years.

Green synthetic natural carbon dots derived from Fuligo Plantae with inhibitory effect against alcoholic gastric ulcer

Introduction: Fuligo Plantae (FP), the ash that sticks to the bottom of pots or chimneys after weeds burn, has long been used for its hemostatic effects and treatment of gastrointestinal bleeding. Nevertheless, the active ingredient of FP still needs to be further explored. Methods: The microstructure, optical and chemical properties of FP-CDs were characterized. An alcohol-induced gastric ulcer model was utilized to evaluate whether pre-administration of FP-CDs alleviated gastric bleeding symptoms and ameliorated gastric mucosal barrier disruption. In addition, the feces of each group of rats were extracted for 16S rDNA genome sequencing of intestinal flora. Results: FP-CDs with a diameter ranging from 1.4-3.2 nm had abundant chemical groups, which may be beneficial to the exertion of inherent activity. FP-CDs alleviated alcohol-induced gastric ulcer, as demonstrated by activating the extrinsic coagulation pathway, alleviating inflammation, and suppressing oxidative stress levels. More interestingly, FP-CDs can improve the diversity and dysbiosis of intestinal flora in rats with alcohol-induced gastric ulcer. Conclusion: These comes about illustrate the momentous inhibitory effects of FP-CDs on alcoholic gastric ulcer in rats, which give a modern methodology for investigating the effective ingredient of FP, and lay an experimental basis for the application of FP-CDs in the clinical treatment of alcoholic gastric ulcer.

Recent trends in macromolecule-conjugated hybrid quantum dots for cancer theranostic applications

Quantum dots (QDs) are small nanoparticles with semiconductor properties ranging from 2 to 10 nanometers comprising 10-50 atoms. The single wavelength excitation character of QDs makes it more significant, as it can excite multiple particles in a confined surface simultaneously by narrow emission. QDs are more photostable than traditional organic dyes; however, when injected into tissues, whole animals, or ionic solutions, there is a significant loss of fluorescence. HQD-based probes conjugated with cancer-specific ligands, antibodies, or peptides are used in clinical diagnosis. It is more precise and reliable than standard immunohistochemistry (IHC) at minimal protein expression levels. Advanced clinical studies use photodynamic therapy (PDT) with fluorescence imaging to effectively identify and treat cancer. Recent studies revealed that a combination of unique characteristics of QDs, including their fluorescence capacity and abnormal expression of miRNA in cancer cells, were used for the detection and monitoring progression of cancer. In this review, we have highlighted the unique properties of QDs and the theranostic behavior of various macromolecule-conjugated HQDs leading to cancer treatment.

Carbon Nanomaterials (CNMs) in Cancer Therapy: A Database of CNM-Based Nanocarrier Systems

Carbon nanomaterials (CNMs) are an incredibly versatile class of materials that can be used as scaffolds to construct anticancer nanocarrier systems. The ease of chemical functionalisation, biocompatibility, and intrinsic therapeutic capabilities of many of these nanoparticles can be leveraged to design effective anticancer systems. This article is the first comprehensive review of CNM-based nanocarrier systems that incorporate approved chemotherapy drugs, and many different types of CNMs and chemotherapy agents are discussed. Almost 200 examples of these nanocarrier systems have been analysed and compiled into a database. The entries are organised by anticancer drug type, and the composition, drug loading/release metrics, and experimental results from these systems have been compiled. Our analysis reveals graphene, and particularly graphene oxide (GO), as the most frequently employed CNM, with carbon nanotubes and carbon dots following in popularity. Moreover, the database encompasses various chemotherapeutic agents, with antimicrotubule agents being the most common payload due to their compatibility with CNM surfaces. The benefits of the identified systems are discussed, and the factors affecting their efficacy are detailed.

Polyethylenimine-functionalized nitrogen and sulfur co-doped carbon dots as effective fluorescent probes for detection of Hg2+ ions

Surface modification of nitrogen and sulfur co-doped carbon quantum dots (N, S-CDs) were performed using cysteine and polyethylenimine as raw materials. The prepared N, S-CDs exhibited excitation-independent in the range of 300-380 nm. Furthermore, mercury(II) ions (Hg²⁺) can effectively quench the fluorescence intensity of the N, S-CDs. Based on this, we developed a fluorescence sensor with high sensitivity and selectivity to detect Hg²⁺. Under optimized conditions, the sensor showed good linearity in the range of 0-500 nM, and the limit of detection is 9.2 nM. Further, the sensor showed high sensitivity to Hg²⁺ in lake water and rice samples. The recovery of the Hg²⁺ in lake water and rice samples ranged between 98.2 % and 109.5 % with a relative standard deviation below 5.8 %. With outstanding sensitivity and selectivity, the fluorescence sensor provides a promising platform for monitoring Hg²⁺ in real samples.

Glycyrrhizae radix et Rhizoma-Derived Carbon Dots and Their Effect on Menopause Syndrome in Ovariectomized Mice

With the extension of the human life span and the increasing pressure of women's work and life, menopause syndrome (MPS) refers to a problem that puzzles almost all women worldwide. Hormone replacement treatment (HRT) can effectively mitigate the symptoms but can also exert adverse effects to a certain extent. Glycyrrhizae radix et rhizome (GRR) is commonly made into a charcoal processed product, termed GRR Carbonisatas (GRRC), for use in traditional Chinese medicine (TCM). GRRC is widely used to treat MPS and other gynecological diseases. In this study, GRRC was prepared through pyrolysis. Subsequently, GRR-derived carbon dots (GRR-CDs) were purified through dialysis and characterized using transmission electron microscopy, high-resolution transmission electron microscopy, Fourier-transform infrared, ultraviolet, fluorescence, X-ray photoelectron microscopy, and high-performance liquid chromatography. The effects of GRR-CDs on MPS were examined and confirmed using ovariectomized female mice models. The GRR-CDs ranged from 1.0 to 3.0 nm in diameter and with multiple surface chemical groups, as indicated by the results. GRR-CDs can elevate the estradiol (E2) level of healthy female mice. Moreover, GRR-CDs can alleviate MPS using the typical ovariectomized mice model, as confirmed by elevating the estradiol (E2) level and reducing the degree of follicle stimulating hormone (FSH) and luteinizing hormone (LH) and raising the degree of uterine atrophy. The results of this study suggested that GRR-CDs may be a potential clinical candidate for the treatment of MPS, which also provides a possibility for nanodrugs to treat hormonal diseases.

Additively manufactured Bi-functionalized bioceramics for reconstruction of bone tumor defects

Bone tissue exhibits critical factors for metastatic cancer cells and represents an extremely pleasant spot for further growth of tumors. The number of metastatic bone lesions and primary tumors that arise directly from cells comprised in the bone milieu is constantly increasing. Bioceramics have recently received significant attention in bone tissue engineering and local drug delivery applications. Additionally, additive manufacturing of bioceramics offers unprecedented advantages including the possibilities to fill irregular voids after the resection and fabricate patient-specific implants. Herein, we investigated the recent advances in additively manufactured bioceramics and ceramic-based composites that were used in the local bone tumor treatment and reconstruction of bone tumor defects. Furthermore, it has been extensively explained how to bi-functionalize ceramics-based biomaterials and what current limitations impede their clinical application. We have also discussed the importance of further development into ceramic-based biomaterials and molecular biology of bone tumors to: (1) discover new potential therapeutic targets to enhance conventional therapies, (2) local delivering of bio-molecular agents in a customized and "smart" way, and (3) accomplish a complete elimination of tumor cells in order to prevent tumor recurrence formation. We emphasized that by developing the research focus on the introduction of novel 3D-printed bioceramics with unique properties such as stimuli responsiveness, it will be possible to fabricate smart bioceramics that promote bone regeneration while minimizing the side-effects and effectively eradicate bone tumors while promoting bone regeneration. In fact, by combining all these therapeutic strategies and additive manufacturing, it is likely to provide personalized tumor-targeting therapies for cancer patients in the foreseeable future. STATEMENT OF SIGNIFICANCE: To increase the survival rates of cancer patients, different strategies such as surgery, reconstruction, chemotherapy, radiotherapy, etc have proven to be essential. Nonetheless, these therapeutic protocols have reached a plateau in their effectiveness due to limitations including drug resistance, tumor recurrence after surgery, toxic side-effects, and impaired bone regeneration following tumor resection. Hence, novel approaches to specifically and locally attack cancer cells, while also regenerating the damaged bony tissue, have being developed in the past years. This review sheds light to the novel approaches that enhance local bone tumor therapy and reconstruction procedures by combining additive manufacturing of ceramic biomaterials and other polymers, bioactive molecules, nanoparticles to affect bone tumor functions, metabolism, and microenvironment.

Optical Properties of Tricarboxylic Acid-Derived Carbon Dots

Herein, we report the characterization of two types of luminescent carbon dots (CDs) synthesized by the hydrothermal treatment of citric acid and trans-aconitic acid by using ammonia solution as a nitrogen dopant. The lateral size range of nanoparticles for CDs lies in the range of 3-15 nm. The intense blue photoluminescence (PL) was emitted by the CDs at around 409-435 nm under the excitation of 320 nm. The PL quantum yield of the synthesized CDs ranged from 26.4 to 51%. Our results of the structural and optical properties of CDs imply that molecular fluorophores are an important part of the structure; in particular, the main contribution to the PL is carried by the fluorophores based on citrazinic acid derivatives, which formed during the synthesis of CDs.

Carbon nanomaterials for phototherapy

Phototherapy attracts increasing interest for broad bio-applications due to its noninvasive and highly selective nature. Owing to their good biocompatibility, unique optoelectronic properties and size/surface effects, carbon nanomaterials show great promise for phototherapy. Various carbon nanomaterials have been demonstrated as efficient phototherapy agents for a large variety of phototherapeutic applications, including cancer treatment, anti-bacteria, and Alzheimer's disease. This review summarizes the recent progress of carbon nanomaterials for phototherapy. Current challenges and future perspectives are also discussed.

Galactosylated Polymer/Gold Nanorods Nanocomposites for Sustained and Pulsed Chemo-Photothermal Treatments of Hepatocarcinoma

In this paper, we propose a rational design of a hybrid nanosystem capable of locally delivering a high amount of hydrophobic anticancer drugs (sorafenib or lenvatinib) and heat (hyperthermia) in a remote-controlled manner. We combined in a unique nanosystem the excellent NIR photothermal conversion of gold nanorods (AuNRs) with the ability of a specially designed galactosylated amphiphilic graft copolymer (PHEA-g-BIB-pButMA-g-PEG-GAL) able to recognize hepatic cells overexpressing the asialoglycoprotein receptor (ASGPR) on their membranes, thus giving rise to a smart composite nanosystem for the NIR-triggered chemo-phototherapy of hepatocarcinoma. In order to allow the internalization of AuNRs in the hydrophobic core of polymeric nanoparticles, AuNRs were coated with a thiolated fatty acid (12-mercaptododecanoic acid). The drug-loaded hybrid nanoparticles were prepared by the nanoprecipitation method, obtaining nanoparticles of about 200 nm and drug loadings of 9.0 and 5.4% w/w for sorafenib and lenvatinib, respectively. These multifunctional nanosystems have shown to convert NIR radiation into heat and release charged drugs in a remote-controlled manner. Then, the biocompatibility and synergistic effects of a chemo-phototherapy combination, as well the receptor-mediated internalization, were evaluated by an in vitro test on HepG2, HuH7, and NHDF. The results indicate that the proposed nanoparticles can be considered to be virtuous candidates for an efficient and selective dual-mode therapy of hepatocarcinoma.

Luminescent Silicon Nanowires as Novel Sensor for Environmental Air Quality Control

Air quality monitoring is an increasingly debated topic nowadays. The increasing spillage of waste products released into the environment has contributed to the increase in air pollution. Consequently, the production of increasingly performing devices in air monitoring is increasingly in demand. In this scenario, the attention dedicated to workplace safety monitoring has led to the developing and improving of new sensors. Despite technological advancements, sensors based on nanostructured materials are difficult to introduce into the manufacturing flow due to the high costs of the processes and the approaches that are incompatible with the microelectronics industry. The synthesis of a low-cost ultra-thin silicon nanowires (Si NWs)-based sensor is here reported, which allows us the detection of various dangerous gases such as acetone, ethanol, and the ammonia test as a proof of concept in a nitrogen-based mixture. A modified metal-assisted chemical etching (MACE) approach enables to obtain ultra-thin Si NWs by a cost-effective, rapid and industrially compatible process that exhibit an intense light emission at room temperature. All these gases are common substances that we find not only in research or industrial laboratories, but also in our daily life and can pose a serious danger to health, even at small concentrations of a few ppm. The exploitation of the Si NWs optical and electrical properties for the detection of low concentrations of these gases through their photoluminescence and resistance changes will be shown in a nitrogen-based gas mixture. These sensing platforms give fast and reversible responses with both optical and electrical transductions. These high performances and the scalable synthesis of Si NWs could pave the way for market-competitive sensors for ambient air quality monitoring.