N-Doped Carbon Quantum Dot (NCQD)-Deposited Carbon Capsules for Synergistic Fluorescence Imaging and Photothermal Therapy of Oral Cancer

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.

Recent advances on hyperthermia therapy applications of carbon-based nanocomposites

Generally, hyperthermia is referred to the composites capability to increase local temperature in such a way that the generated heat would lead to cancerous or bacteria cells destruction, with minimum damage to normal tissue cells. Many different materials have been utilized for hyperthermia application via different heat generating methods. Carbon-based nanomaterials consisting of graphene oxide (GO), carbon nanotube (CNT), carbon dot (CD) and carbon quantum dot (CQD), nanodiamond (ND), fullerene and carbon fiber (CF), have been studied significantly for different applications including hyperthermia due to their biocompatibility, biodegradability, chemical and physical stability, thermal and electrical conductivity and in some cases photothermal conversion. Therefore, in this comprehensive review, a structure-based view on carbon nanomaterials application in hyperthermia therapy of cancer and bacteria via various methods such as optical, magnetic, ultrasonic and radiofrequency-induced hyperthermia is presented.

Review of the Role of Nanotechnology in Overcoming the Challenges Faced in Oral Cancer Diagnosis and Treatment

Throughout the world, oral cancer is a common and aggressive malignancy with a high risk of morbidity, mortality, and recurrence. The importance of early detection in cancer prevention and disease treatment cannot be overstated. Conventional therapeutic strategies have minor difficulties but considerable side effects and unfavourable consequences in clinical applications. Hence, there is a requirement for effective ways for early detection and treatment of oral cancer. At present, numerous forms of nanoparticles have piqued researchers' interest as a potentially useful tool for diagnostic probes and medicinal devices. Because of their inherent physicochemical properties and customizable surface modification, they are able to circumvent some of restrictions and accomplish the intended diagnostic and therapeutic impact. Nanotechnology is a unique field that has revolutionised the industry and is paving the way for new treatments for oral cancer. It can help with a better diagnosis with less harmful substances and is setting current guidelines for treatment. The use of nanotechnology in cancer diagnosis, therapy, and care improves clinical practise dramatically. The different types of nanoparticles that have been developed for the diagnosis and therapy of oral cancers will be covered in this study. The difficulties and potential uses of nanoparticles in the treatment and diagnosis of oral cancer are then highlighted. In order to emphasise existing difficulties and potential remedies for oral cancer, a prospective view of the future is also provided.

Nanoparticles as drug delivery systems in the treatment of oral squamous cell carcinoma: current status and recent progression

Oral squamous cell carcinoma (OSCC) is a common human malignancy with an estimated incidence of around 377,713 new cases worldwide in 2020. Despite the advance in clinical management, some of OSCC patients still miss the opportunity of completable resection of tumor, and have to accept medical therapies, e.g., chemotherapy, radiotherapy, or immunotherapy when the disease develops into the advanced stage. However, these therapies have been reported to be far from ideal due to the low efficiency of conventional delivery approaches. To obtain a better therapeutic effect, considerable attempts have been made toward to develop an effective drug delivery system (DDS). Nanoparticles (NPs) including inorganic NPs, polymer NPs, lipid NP, extracellular vesicles and cell membrane-based NPs have been evaluated as the better DDS candidates that can specifically accumulate in the tumor microenvironment along with a large amount of blood vessels. Emerging evidence suggested that NPs formulated with anticancer drugs including chemotherapeutic drugs, radiotherapy and immunotarget antibodies could remarkably improve the release and increase concentration of these drugs at the tumor site and show a better therapeutic efficacy, suggesting that NPs might serve as promising DDSs in the treatment of OSCC. Therefore, we have conducted this review to summarize recent progression and current status of diverse NPs as DDSs in this research field.

Insight on nano drug delivery systems with targeted therapy in treatment of oral cancer

Oral cancer is a type of cancer that develops in the mouth and is one of the deadliest malignancies in the world. Currently surgical, radiation therapy, and chemotherapy are most common treatments. Better treatment and early detection strategies are required. Chemotherapeutic drugs fail frequently due to toxicity and poor tumor targeting. There are high chances of failure of chemotherapeutic drugs due to toxicity. Active, passive, and immunity-targeting techniques are devised for tumor-specific activity. Nanotechnology-based drug delivery systems are the best available solution and important for precise targeting. Nanoparticles, liposomes, exosomes, and cyclodextrins are nano-based carriers for drug delivery. Nanotechnology is being used to develop new techniques such as intratumoral injections, microbubble mediated ultrasonic therapy, phototherapies, and site-specific delivery. This systematic review delves into the details of such targeted and nano-based drug delivery systems in order to improve patient health and survival rates in oral cancer.

Green Carbon Dots: Synthesis, Characterization, Properties and Biomedical Applications

Carbon dots (CDs) are a new category of crystalline, quasi-spherical fluorescence, "zero-dimensional" carbon nanomaterials with a spatial size between 1 nm to 10 nm and have gained widespread attention in recent years. Green CDs are carbon dots synthesised from renewable biomass such as agro-waste, plants or medicinal plants and other organic biomaterials. Plant-mediated synthesis of CDs is a green chemistry approach that connects nanotechnology with the green synthesis of CDs. Notably, CDs made with green technology are economical and far superior to those manufactured with physicochemical methods due to their exclusive benefits, such as being affordable, having high stability, having a simple protocol, and being safer and eco-benign. Green CDs can be synthesized by using ultrasonic strategy, chemical oxidation, carbonization, solvothermal and hydrothermal processes, and microwave irradiation using various plant-based organic resources. CDs made by green technology have diverse applications in biomedical fields such as bioimaging, biosensing and nanomedicine, which are ascribed to their unique properties, including excellent luminescence effect, strong stability and good biocompatibility. This review mainly focuses on green CDs synthesis, characterization techniques, beneficial properties of plant resource-based green CDs and their biomedical applications. This review article also looks at the research gaps and future research directions for the continuous deepening of the exploration of green CDs.

Green Synthesis of Near-Infrared Copper-Doped Carbon Dots from Alcea for Cancer Photothermal Therapy

Heteroatom-doped carbon dots (CDs) with optical absorbance in the near-infrared (NIR) region can provide an opportunity for selective cancer photothermal therapy (PTT). Here, an eco-friendly, simple, cost-efficient, and one-step hydrothermal method was developed to synthesize copper-doped CDs (Cu-doped CDs). The Alcea extract as the carbon source was combined with CuSO₄ as the dopant. Microscopic and spectroscopic analyses showed that spherical and monodisperse Cu-doped CDs (Cu-dCDs) with sizes below 10 nm have bright fluorescence with photoluminescence quantum yields of 11.1%. Cu-dCDs exhibited an excellent single absorbance peak at 800 nm and strong emission at 460 nm when excited at 370 nm. In vitro low cytotoxicity and the Cu-dCD-mediated cell PTT with the photothermal conversion efficiency (39.3%) show that cell internalization of Cu-doped CDs under an 800 nm NIR laser can induce cell thermal death.

Progress of Nanomaterials-Based Photothermal Therapy for Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the top 15 most prevalent cancers worldwide. However, the current treatment models for OSCC (e.g., surgery, chemotherapy, radiotherapy, and combination therapy) present several limitations: damage to adjacent healthy tissue, possible recurrence, low efficiency, and severe side effects. In this context, nanomaterial-based photothermal therapy (PTT) has attracted extensive research attention. This paper reviews the latest progress in the application of biological nanomaterials for PTT in OSCC. We divide photothermal nanomaterials into four categories (noble metal nanomaterials, carbon-based nanomaterials, metal compounds, and organic nanomaterials) and introduce each category in detail. We also mention in detail the drug delivery systems for PTT of OSCC and briefly summarize the applications of hydrogels, liposomes, and micelles. Finally, we note the challenges faced by the clinical application of PTT nanomaterials and the possibility of further improvement, providing direction for the future research of PTT in OSCC treatment.

Advances in nanomaterials for the diagnosis and treatment of head and neck cancers: A review

Nanomaterials (NMs) have increasingly been used for the diagnosis and treatment of head and neck cancers (HNCs) over the past decade. HNCs can easily infiltrate surrounding tissues and form distant metastases, meaning that most patients with HNC are diagnosed at an advanced stage and often have a poor prognosis. Since NMs can be used to deliver various agents, including imaging agents, drugs, genes, vaccines, radiosensitisers, and photosensitisers, they play a crucial role in the development of novel technologies for the diagnosis and treatment of HNCs. Indeed, NMs have been reported to enhance delivery efficiency and improve the prognosis of patients with HNC by allowing targeted delivery, controlled release, responses to stimuli, and the delivery of multiple agents. In this review, we consider recent advances in NMs that could be used to improve the diagnosis, treatment, and prognosis of patients with HNC and the potential for future research.

Exogenously Triggered Nanozyme for Real-Time Magnetic Resonance Imaging-Guided Synergistic Cascade Tumor Therapy

The uncontrolled treatment process and high concentration of intracellular glutathione compromise the therapeutic efficacies of chemodynamic therapy (CDT). Here, iron oxide nanocrystals embedded in N-doped carbon nanosheets (IONCNs) are designed as a near-infrared light-triggered nanozyme for synergistic cascade tumor therapy. The IONCNs can absorb and convert 980 nm light to local heat, which induces the dissolution of iron oxide for generating Fe²⁺/Fe³⁺ in a weak acid environment, apart from thermal ablation of cancer cells. The formed Fe²⁺ takes on the active site for the Fenton reaction. The formed Fe³⁺ acts as glutathione peroxidase to magnify oxidative stress, improving the antitumor performance. The IONCNs can be used to visually track the treatment process via magnetic resonance imaging. Such IONCNs demonstrate great potential as an exogenously triggered nanozyme via an integrated cascade reaction for imaging-guided synergistic cancer therapy.

A Review: Potential Application and Outlook of Photothermal Therapy in Oral Cancer Treatment

As one of the most common malignant tumors, oral cancer threatens people's health worldwide. However, traditional therapies, including surgery, radiotherapy, and chemotherapy can't meet the requirement of cancer cure. Photothermal therapy (PTT) has attracted widespread attentions for its advantages of the noninvasive process, few side effects, and promising tumor ablation. Up to now, three types of photothermal agents (PTAs) have been widely employed in oral cancer therapies, which involve metallic materials, carbon-based materials, and organic materials. Previous research mainly introduced hybrid materials due to benefits from the synergistic effect of multiple functions. In this review, we present the advancement of each type PTAs for oral cancer treatment in recent years. In each part, we introduce the properties and synthesis of each PTA, summarize the current studies, and analyze their potential applications. Furthermore, we discuss the status quo and the deficiencies hindering the clinical application of PTT, based on which gives the perspective of its future developing directions.

H2O2 generation enhancement by ultrasonic nebulisation with a zinc layer for spray disinfection

With the outbreak of COVID-19, microbial pollution has gained increasing attention as a threat to human health. Consequently, many research efforts are being devoted to the development of efficient disinfection methods. In this context, hydrogen peroxide (H₂O₂) stands out as a green and broad-spectrum disinfectant, which can be produced and sprayed in the air directly by cavitation in ultrasonic nebulisation. However, the yield of H₂O₂ obtained by ultrasonic nebulisation is too low to satisfy the requirements for disinfection by spraying and needs to be improved to achieve efficient disinfection of the air and objects. Herein, we report the introduction of a zinc layer into an ultrasonic nebuliser to improve the production of H₂O₂ and generate additional Zn²⁺ by self-corrosion, achieving good disinfecting performance. Specifically, a zinc layer was assembled on the oscillator plate of a commercial ultrasonic nebuliser, resulting in a 21-fold increase in the yield of H₂O₂ and the production of 4.75 μg/mL Zn²⁺ in the spraying droplets. When the generated water mist was used to treat a bottle polluted with Escherichia coli for 30 min, the sterilisation rate reached 93.53%. This ultrasonic nebulisation using a functional zinc layer successfully enhanced the production of H₂O₂ while generating Zn²⁺, providing a platform for the development of new methodologies of spray disinfection.

PEG-PEI-modified gated N-doped mesoporous carbon nanospheres for pH/NIR light-triggered drug release and cancer phototherapy

A novel hybrid drug carrier has been designed, taking N-doped mesoporous carbon (NMCS) as the core and PEG-PEI as the outer shell. NMCS was functionalized with a photocleavable nitrobenzyl-based linker following a click reaction. Gemcitabine was loaded into NMCS prior to the functionalization via π-π stacking interactions. NIR and the pH-responsive behavior of NMCS-linker-PEG-PEI bestow the multifunctional drug carrier with the controlled release of gemcitabine triggered by dual stimuli. The NMCS core upconverts NIR light to UV, which is absorbed by a photosensitive molecular gate and results in its cleavage and drug release. Further, NMCS converts NIR to heat, which deforms the outside polymer shell, thus triggering the drug release process. The release can be promptly arrested if the NIR source is switched off. A promising gemcitabine release of 75% has been achieved within 24 h under the dual stimuli of pH and temperature. NMCS-linker-PEG-PEI produced reactive oxygen species (ROS), which were verified in FaDu cells using flow cytometry. In vitro experiments showed that the NMCS-linker-PEG-PEI-GEM hybrid particle can induce synergistic therapeutic effects in FADU cells when exposed to the NIR light.

Advances in Cancer Therapeutics: Conventional Thermal Therapy to Nanotechnology-Based Photothermal Therapy

In this review, advancement in cancer therapy that shows a transition from conventional thermal therapies to laser-based photothermal therapies is discussed. Laser-based photothermal therapies are gaining popularity in cancer therapeutics due to their overall outcomes. In photothermal therapy, light is converted into heat to destruct the various types of cancerous growth. The role of nanoparticles as a photothermal agent is emphasized in this review article. Magnetic, as well as non-magnetic, nanoparticles have been effectively used in the photothermal-based cancer therapies. The discussion includes a critical appraisal of in vitro and in vivo, as well as the latest clinical studies completed in this area. Plausible evidence suggests that photothermal therapy is a promising avenue in the treatment of cancer.

Recent advances in near infrared light responsive multi-functional nanostructures for phototheranostic applications

Light-based theranostics have become indispensable tools in the field of cancer nanomedicine. Specifically, near infrared (NIR) light mediated imaging and therapy of deeply seated tumors using a single multi-functional nanoplatform have gained significant attention. To this end, several multi-functional nanomaterials have been utilized to tackle cancer and thereby achieve significant outcomes. The present review mainly focuses on the recent advances in the development of NIR light activatable multi-functional materials such as small molecules, quantum dots, and metallic nanostructures for the diagnosis and treatment of deeply seated tumors. The need for improved disease detection and enhanced treatment options, together with realistic considerations for clinically translatable nanomaterials will be the key driving factors for theranostic agent research in the near future. NIR-light mediated cancer imaging and therapeutic approaches offer several advantages in terms of minimal invasiveness, deeper tissue penetration, spatiotemporal resolution, and molecular specificities. Herein, we have reviewed the recent developments in NIR light responsive multi-functional nanostructures for phototheranostic applications in cancer therapy.

Injectable hydrogel-mediated combination of hyperthermia ablation and photo-enhanced chemotherapy in the NIR-II window for tumor eradication

Local administration of therapeutic agents with long-term retention capabilities efficiently avoids nonspecific distribution in normal organs with an increased drug concentration in pathological tissue. Herein, we developed an injectable and degradable alginate-calcium (Ca2+) hydrogel for the local administration of corn-like Au/Ag nanorods (NRs) and doxorubicin hydrochloride (DOX·HCl). The immobilized Au/Ag NRs with strong absorbance in the near-infrared II (NIR-II) window efficiently ablated the majority of tumor cells after 1064 nm laser irradiation and triggered the release of DOX to kill residual tumor cells. As a result, injectable hydrogel-mediated NIR-II photothermal therapy (PTT) and chemotherapy efficiently inhibited tumor growth, resulting in the complete eradication of tumors in most of the treated mice. Furthermore, owing to the confinement of the Au/Ag NRs and DOX·HCl within the hydrogel, such treatment exhibited excellent biocompatibility.

New Insight into the Fluorescence Quenching of Nitrogen-Containing Carbonaceous Quantum Dots-From Surface Chemistry to Biomedical Applications

Carbon-based quantum dots are widely suggested as fluorescent carriers of drugs, genes or other bioactive molecules. In this work, we thoroughly examine the easy-to-obtain, biocompatible, nitrogen-containing carbonaceous quantum dots (N-CQDs) with stable fluorescent properties that are resistant to wide-range pH changes. Moreover, we explain the mechanism of fluorescence quenching at extreme pH conditions. Our in vitro results indicate that N-CQDs penetrate the cell membrane; however, fluorescence intensity measured inside the cells was lower than expected from carbonaceous dots extracellular concentration decrease. We studied the mechanism of quenching and identified reduced form of β-nicotinamide adenine dinucleotide (NADH) as one of the intracellular quenchers. We proved it experimentally that the elucidated redox process triggers the efficient reduction of amide functionalities to non-fluorescent amines on carbonaceous dots surface. We determined the 5 nm-wide reactive redox zone around the N-CQD surface. The better understanding of fluorescence quenching will help to accurately quantify and dose the internalized carbonaceous quantum dots for biomedical applications.

Nanoparticles for Oral Cancer Diagnosis and Therapy

Oral cancer is the sixth most common malignant cancer, affecting the health of people with an unacceptably high mortality rate. Despite numerous clinical methods in the diagnosis and therapy of oral cancer (e.g., magnetic resonance imaging, computed tomography, surgery, and chemoradiotherapy), they still remain far from optimal. Therefore, an urgent need exists for effective and practical techniques of early diagnosis and effective therapy of oral cancer. Currently, various types of nanoparticles have aroused wide public concern, representing a promising tool for diagnostic probes and therapeutic devices. Their inherent physicochemical features, including ultrasmall size, high reactivity, and tunable surface modification, enable them to overcome some of the limitations and achieve the expected diagnostic and therapeutic effect. In this review, we introduce different types of nanoparticles that emerged for the diagnosis and therapy of oral cancers. Then, the challenges and future perspectives for nanoparticles applied in oral cancer diagnosis and therapy are presented. The objective of this review is to help researchers better understand the effect of nanoparticles on oral cancer diagnosis and therapy and may accelerate breakthroughs in this field.

Drug Delivery (Nano)Platforms for Oral and Dental Applications: Tissue Regeneration, Infection Control, and Cancer Management

The oral cavity and oropharynx are complex environments that are susceptible to physical, chemical, and microbiological insults. They are also common sites for pathological and cancerous changes. The effectiveness of conventional locally-administered medications against diseases affecting these oral milieus may be compromised by constant salivary flow. For systemically-administered medications, drug resistance and adverse side-effects are issues that need to be resolved. New strategies for drug delivery have been investigated over the last decade to overcome these obstacles. Synthesis of nanoparticle-containing agents that promote healing represents a quantum leap in ensuring safe, efficient drug delivery to the affected tissues. Micro/nanoencapsulants with unique structures and properties function as more favorable drug-release platforms than conventional treatment approaches. The present review provides an overview of newly-developed nanocarriers and discusses their potential applications and limitations in various fields of dentistry and oral medicine.

Highly Efficient Photothermal Therapy with Cell-Penetrating Peptide-Modified Bumpy Au Triangular Nanoprisms using Low Laser Power and Low Probe Dose

Photothermal therapy (PTT) exploits nanomaterials with optimal heat conversion and cellular penetration using near-infrared (NIR) laser irradiation. However, current PTT agents suffer from inefficient heat conversion, poor intracellular delivery, and a high dose of probes along with excessive laser irradiation, causing limited therapeutic outcomes. Here, bumpy Au triangular nanoprisms (BATrisms) are developed for increasing the surface area, improving cell penetration, shifting the absorption peak to the NIR region, and enhancing the photothermal conversion efficiency (∼86%). Further, leucine (L)- and lysine (K)-rich cell-penetrating peptides (LK peptides) were employed to largely improve their cellular uptake efficiency. Importantly, a significant in vivo therapeutic efficacy with LK-BATrisms was demonstrated in a triple-negative breast cancer xenograft mice model. A very small dose of LK-BATrism (2.5 μg Au) was enough to exert antitumor efficacy under very low laser power (808 nm, 0.25 W/cm²), causing minimal tissue damages while very efficiently killing cancer cells.

Nanotechnology-based drug delivery systems for enhanced diagnosis and therapy of oral cancer

Oral cancer is a common malignant life-threatening tumor. Despite some advances in traditional therapy, mortality and mobidity rates are high due to delayed diagnosis and ineffective treatment. Additionally, some patients inevitably suffer from various fatal adverse effects during the course of therapy. Therefore, it is imperative to develop novel methods to eradicate oral cancer cells with minimal adverse effects on normal cells. Nanotechnology is a promising and novel vehicle for the diagnosis and treatment of oral cancer with encouraging recent achievements. In this review, we present state-of-the-art nanotechnology-based drug delivery systems employed in the domain of oral cancer, especially for its enhanced diagnosis and therapy. We describe in detail the types of nanotechnology used in the management of oral cancer and summarize administration routes of nanodrugs. Finally, the potential and prospects of nanotechnology-based drug delivery systems as promising modalities of diagnosis and therapy of oral cancer are highlighted.

Hollow Porous Carbon Coated FeS2-Based Nanocatalysts for Multimodal Imaging-Guided Photothermal, Starvation, and Triple-Enhanced Chemodynamic Therapy of Cancer

Specific chemical reactions only happen in the tumor region and produce abundant special chemicals to in situ trigger a train of biological and pathological effects that may enable tumor-specific curative effects to treat cancer without causing serious side effects on normal cells or organs. Chemodynamic therapy (CDT) is a rising tactic for cancer therapy, which induces cancer cell death via a localized Fenton reaction. However, the tumor therapeutic effect is limited by the efficiency of the chemical reaction and relies heavily on the catalyst. Here, we constructed hollow porous carbon coated FeS₂ (HPFeS₂@C)-based nanocatalysts for triple-enhanced CDT. Tannic acid was encapsulated in HPFeS₂@C for reducing Fe³⁺ to Fe²⁺, which had a better catalytic activity to accelerate the Fenton reaction. Afterward, glucose oxidase (GOx) in nanocatalysts could consume glucose in the tumor microenvironment and in situ synchronously produce H₂O₂, which could improve Fenton reaction efficiency. Meanwhile, the consumption of glucose could lead to the starvation effect for cancer starvation therapy. The photothermal effects of HPFeS₂@C could generate heat, which further sped up the Fenton process and implemented synergetic photothermal therapy/starvation therapy/CDT. The biodistribution of nanoparticles was investigated by multimodal magnetic resonance, ultrasound, and photoacoustic imaging. These nanocatalysts could trigger the catalytic Fenton reaction at a high degree, which might provide a good paradigm for nanocatalytic tumor therapy.