Multi-stimuli responsive nanosystem modified by tumor-targeted carbon dots for chemophototherapy synergistic therapy

Recent Review on Biological Barriers and Host-Material Interfaces in Precision Drug Delivery: Advancement in Biomaterial Engineering for Better Treatment Therapies

Preclinical and clinical studies have demonstrated that precision therapy has a broad variety of treatment applications, making it an interesting research topic with exciting potential in numerous sectors. However, major obstacles, such as inefficient and unsafe delivery systems and severe side effects, have impeded the widespread use of precision medicine. The purpose of drug delivery systems (DDSs) is to regulate the time and place of drug release and action. They aid in enhancing the equilibrium between medicinal efficacy on target and hazardous side effects off target. One promising approach is biomaterial-assisted biotherapy, which takes advantage of biomaterials' special capabilities, such as high biocompatibility and bioactive characteristics. When administered via different routes, drug molecules deal with biological barriers; DDSs help them overcome these hurdles. With their adaptable features and ample packing capacity, biomaterial-based delivery systems allow for the targeted, localised, and prolonged release of medications. Additionally, they are being investigated more and more for the purpose of controlling the interface between the host tissue and implanted biomedical materials. This review discusses innovative nanoparticle designs for precision and non-personalised applications to improve precision therapies. We prioritised nanoparticle design trends that address heterogeneous delivery barriers, because we believe intelligent nanoparticle design can improve patient outcomes by enabling precision designs and improving general delivery efficacy. We additionally reviewed the most recent literature on biomaterials used in biotherapy and vaccine development, covering drug delivery, stem cell therapy, gene therapy, and other similar fields; we have also addressed the difficulties and future potential of biomaterial-assisted biotherapies.

Rational construction of CQDs-based targeted multifunctional nanoplatform for synergistic chemo-photothermal tumor therapy

Photothermal therapy combined with chemotherapy has shown great promise in the treatment of cancer. In this synergistic system, a safe, stable, and efficient photothermal agent is desired. Herein, an effective photothermal agent, carbon quantum dots (CQDs), was initially synthesized and then rationally constructed a folic acid (FA)-targeted photothermal multifunctional nanoplatform by encapsulating CQDs and the anticancer drug doxorubicin (DOX) in the liposomes. Indocyanine green (ICG), a near infrared (NIR) photothermal agent, approved by the U.S. Food and Drug Administration, was embedded in the bilayer membrane to further enhance the photothermal effects and facilitate the rapid cleavage of liposomes for drug release. Triggered by the NIR laser, this engineered photothermal multifunctional nanoplatform, not only exhibited an excellent performance with the photothermal conversion efficiency of up to 47.14%, but also achieved controlled release of the payloads. In vitro, and in vivo experiments demonstrated that the photothermal multifunctional nanoplatform had excellent biocompatibility, enhanced tumor-specific targeting, stimuli-responsive drug release, effective cancer cell killing and tumor suppression through multi-modal synergistic therapy. The successful construction of this NIR light-triggered targeted photothermal multifunctional nanoplatform will provide a promising strategy for the design and development of synergistic chemo-photothermal combination therapy and improve the therapeutic efficacy of cancer treatment.

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

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

Recent Progress on Chiral Carbon Dots: Synthetic Strategies and Biomedical Applications

The discovery of chiral carbon dots (Ch-CDs) has opened up an exciting new research direction in the field of carbon dots. It not only retains the chirality of the precursor and exhibits highly symmetric chiral optical properties but also has properties such as chemical stability, antibacterial and antitumor properties, and good biocompatibility of carbon dots. Based on these advantages, the application of Ch-CDs in the biomedical field has attracted significant interest among researchers. However, a comprehensive review of the selection of precursors for Ch-CDs, preparation methods, and applications in biomedical fields is still lacking. Here, we summarize their precursor selection and preparation methods based on recent reports on Ch-CDs and provide the first comprehensive review for specific applications in biomedical engineering, such as biosensing, bioimaging, drug carriers, antibacterial and antibiofilm, and enzyme activity modulation. Finally, we discuss application prospects and challenges that need to be overcome. We hope this review will provide valuable guidance for researchers to prepare novel Ch-CDs and facilitate their application in biomedical engineering.

Synthesis, properties and potential applications of photoluminescent carbon nanoparticles: A review

Photoluminescent-carbon nanoparticles (PL-CNPs) are a new class of materials that received immense interest among researchers due to their distinct characteristics, including photoluminescence, high surface-to-volume ratio, low cost, ease of synthesis, high quantum yield, and biocompatibility. By exploiting these outstanding properties, many studies have been reported on its utility as sensors, photocatalysts, probes for bio-imaging, and optoelectronics applications. From clinical applications to point-of-care test devices, drug loading to tracking of drug delivery, and other research innovations demonstrated PL-CNPs as an emerging material that could substitute conventional approaches. However, some of the PL-CNPs have poor PL properties and selectivity due to the presence of impurities (e.g., molecular fluorophores) and unfavourable surface charges by the passivation molecules, which impede their applications in many fields. To address these issues, many researchers have been paying great attention to developing new PL-CNPs with different composite combinations to achieve high PL properties and selectivity. Herein, we thoroughly discussed the recent development of various synthetic strategies employed to prepare PL-CNPs, doping effects, photostability, biocompatibility, and applications in sensing, bioimaging, and drug delivery fields. Moreover, the review discussed the limitations, future direction, and perspectives of PL-CNPs in possible potential applications.

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.

Rational design of a minimum nanoplatform for maximizing therapeutic potency: Three birds with one stone

Therapeutic modalities and drug formulations play a crucial and prominent role in actualizing effective treatment and radical cures of tumors. However, the therapeutic efficiency was severely limited by tumor recurrence and complex multi-step preparation of formulation. Therefore, the exploration of novel nanoparticles via a simple and green synthesis process for conquering traditional obstacles and improving therapeutic efficiency is an appealing, yet remarkably challenging task. Herein, a universal nanoplatform allows all cancerous cell-targeting, acid-responsive, cell imaging, synergistic chemotherapy, and nucleolar targeted phototherapy function was tactfully designed and constructed by using chemotherapeutic agents ursolic acid (UA), sorafenib (SF), and carbon dots (CDs) photosensitizers (PSs). The designed US NPs were formed by self-assembly of UA and SF associated with electrostatic, π-π stacking, and hydrophobic interactions. After hydrogen bonding reaction with CDs, the obtained (denoted as USC NPs) have a relatively uniform size of an average 125.6 nm, which facilitated the favorable accumulation of drugs at the tumor region through a potential enhanced permeability and retention (EPR) effect as compared to their counterpart of free CDs solution. Both in vitro and in vivo studies revealed that the advanced platform commenced synergistic anticancer therapeutic potency, imperceptible systematical toxicity, and remarkable reticence towards drug-resistant cancer cells. Moreover, the CDs PSs possess intrinsic nucleolus-targeting ability. Taken together, this theranostics system can fully play the role of "killing three birds with one stone" in a safe manner, implying a promising direction for exploring treatment strategies for cancer and endowing them with great potential for future translational research and providing a new vision for the advancing of an exceptionally forceful protocol for practical cancer therapy.

A narrative review on the role of carbon nanoparticles in oncology

The lymphatic system is the first site of metastasis for most tumors and is a common reason for the failure of cancer therapy. The lymphatic system's anatomical properties make it difficult to deliver chemotherapy agents at therapeutic concentrations while avoiding systemic toxicity. Carbon nanoparticles offer a promising alternative for identifying and transporting therapeutic molecules. The larger diameter of lymphatic vessels compared to the diameter of blood vessels, allows carbon nanoparticles to selectively enter the lymphatic system once administered subcutaneously. Carbon nanoparticles stain tumor-draining lymph nodes black following intratumoral injection, making them useful in sentinel lymph node mapping. Drug-loaded carbon nanoparticles allow higher concentrations of chemotherapeutics to accumulate in regional lymph nodes while decreasing plasma drug accumulation. The use of carbon nanoparticles for chemotherapy delivery has been associated with lower mortality, fewer histopathology changes in vital organs, and lower serum concentrations of hepatocellular enzymes. This review will focus on the ability of carbon nanoparticles to target the lymphatics as well as their current and potential applications in sentinel lymph node mapping and oncology treatment regimens. This article is categorized under: Implantable Materials and Surgical Technologies > Nanoscale Tools and Techniques in Surgery.

The Role of Hydrogel in Cardiac Repair and Regeneration for Myocardial Infarction: Recent Advances and Future Perspectives

A myocardial infarction (MI) is the leading cause of morbidity and mortality, seriously threatens human health, and becomes a major health burden of our society. It is urgent to pursue effective therapeutic strategies for the regeneration and restore myocardial function after MI. This review discusses the role of hydrogel in cardiac repair and regeneration for MI. Hydrogel-based cardiac patches and injectable hydrogels are the most commonly used applications in cardiac regeneration medicine. With injectable hydrogels, bioactive compounds and cells can be delivered in situ, promoting in situ repair and regeneration, while hydrogel-based cardiac patches reduce myocardial wall stress, which passively inhibits ventricular expansion. Hydrogel-based cardiac patches work as mechanically supportive biomaterials. In cardiac regeneration medicine, clinical trials and commercial products are limited. Biomaterials, biochemistry, and biological actives, such as intelligent hydrogels and hydrogel-based exosome patches, which may serve as an effective treatment for MI in the future, are still under development. Further investigation of clinical feasibility is warranted. We can anticipate hydrogels having immense translational potential for cardiac regeneration in the near future.

Carbon dot-based nanomaterials: a promising future nano-platform for targeting tumor-associated macrophages

The tumor microenvironment (TME) is the internal environment that tumors depend on for survival and development. Tumor-associated macrophages (TAMs), as an important part of the tumor microenvironment, which plays a crucial role in the occurrence, development, invasion and metastasis of various malignant tumors and has immunosuppressant ability. With the development of immunotherapy, eradicating cancer cells by activating the innate immune system has yielded encouraging results, however only a minority of patients show a lasting response. Therefore, in vivo imaging of dynamic TAMs is crucial in patient-tailored immunotherapy to identify patients who will benefit from immunotherapy, monitor efficacy after treatment, and identify alternative strategies for non-responders. Meanwhile, developing nanomedicines based on TAMs-related antitumor mechanisms to effectively inhibit tumor growth is expected to become a promising research field. Carbon dots (CDs), as an emerging member of the carbon material family, exhibit unexpected superiority in fluorescence imaging/sensing, such as near infrared imaging, photostability, biocompatibility and low toxicity. Their characteristics naturally integrate therapy and diagnosis, and when CDs are combined with targeted chemical/genetic/photodynamic/photothermal therapeutic moieties, they are good candidates for targeting TAMs. We concentrate our discussion on the current learn of TAMs and describe recent examples of macrophage modulation based on carbon dot-associated nanoparticles, emphasizing the advantages of their multifunctional platform and their potential for TAMs theranostics.

Hypoxia mitigation by manganese-doped carbon dots for synergistic photodynamic therapy of oral squamous cell carcinoma

Photodynamic therapy (PDT) is widely used for cancer treatment due to its non-invasive and precise effectiveness, however, hypoxia in the tumor microenvironment greatly limits the efficacy of photodynamic therapy. Compared with conventional photosensitizers, carbon dots (CDs) have great potential. Therefore, developing a water-soluble, low-toxicity photosensitizer based on CDs is particularly important, especially one that can enhance the photodynamic efficacy using the tumor microenvironment to produce oxygen. Herein, manganese-doped carbon dot (Mn-CDs, ∼2.7 nm) nanoenzymes with excellent biocompatibility were prepared by a solvothermal method using ethylenediaminetetraacetic acid manganese disodium salt hydrate and o-phenylenediamine as precursors. TEM, AFM, HR-TEM, XRD, XPS, FT-IR, ζ potential, DLS, UV-Vis, and PL spectra were used to characterize the Mn-CDs. Cancer resistance was assessed using the CCK-8 kit, calcein AM versus propidium iodide (PI) kit, and the Annexin V-FITC/PI cell apoptosis assay kit. The obtained Mn-CDs have excellent near-infrared emission properties, stability, and efficient ¹O₂ generation. Notably, the manganese doping renders CDs with catalase (CAT)-like activity, which leads to the decomposition of acidic H₂O₂ in situ to generate O₂, enhancing the PDT efficacy against OSCC-9 cells under 635 nm (300 mW·cm^-2) irradiation. Thus, this work provides a simple and feasible method for the development of water-soluble photosensitizers with oxygen production, presenting good biosafety for PDT in hypoxic tumors.

Biomaterial-assisted biotherapy: A brief review of biomaterials used in drug delivery, vaccine development, gene therapy, and stem cell therapy

Biotherapy has recently become a hotspot research topic with encouraging prospects in various fields due to a wide range of treatments applications, as demonstrated in preclinical and clinical studies. However, the broad applications of biotherapy have been limited by critical challenges, including the lack of safe and efficient delivery systems and serious side effects. Due to the unique potentials of biomaterials, such as good biocompatibility and bioactive properties, biomaterial-assisted biotherapy has been demonstrated to be an attractive strategy. The biomaterial-based delivery systems possess sufficient packaging capacity and versatile functions, enabling a sustained and localized release of drugs at the target sites. Furthermore, the biomaterials can provide a niche with specific extracellular conditions for the proliferation, differentiation, attachment, and migration of stem cells, leading to tissue regeneration. In this review, the state-of-the-art studies on the applications of biomaterials in biotherapy, including drug delivery, vaccine development, gene therapy, and stem cell therapy, have been summarized. The challenges and an outlook of biomaterial-assisted biotherapies have also been discussed.

Antioxidant, Enzyme, and H2O2-Triggered Melanoma Targeted Mesoporous Organo-Silica Nanocomposites for Synergistic Cancer Therapy

The multi-stimuli responsive drug delivery system has recently attracted attention in cancer treatments, since it can reduce several side effects and enhance cancer therapeutic efficacy. Herein, we present the intracellular antioxidant (glutathione, GSH), enzyme (hyaluronidase, HAase), and hydrogen peroxide (H2O2) triggered mesoporous organo-silica (MOS) nanocomposites for multi-modal treatments via chemo-, photothermal, and photodynamic cancer therapies. A MOS nanoparticle was synthesized by two-types of precursors, tetraethyl orthosilicate (TEOS) and bis[3-(triethoxysilyl)propyl] tetrasulfide (BTES), providing large-sized mesopores and disulfide bonds cleavable by GSH. Additionally, we introduced a new β-cyclodextrin-hyaluronic acid (CDHA) gatekeeper system, enabling nanocomposites to form the specific interaction with the ferrocene (Fc) molecule, control the drug release by the HAase and H2O2 environment, as well as provide the targeting ability against the CD44-overexpressing melanoma (B16F10) cells. Indocyanine green (ICG) and doxorubicin (Dox) were loaded in the MOS-Fc-CDHA (ID@MOS-Fc-CDHA) nanocomposites, allowing for hyperthermia and cytotoxic reactive oxygen species (ROS) under an 808 nm NIR laser irradiation. Therefore, we demonstrated that the ID@MOS-Fc-CDHA nanocomposites were internalized to the B16F10 cells via the CD44 receptor-mediated endocytosis, showing the controlled drug release by GSH, HAase, and H2O2 to enhance the cancer therapeutic efficacy via the synergistic chemo-, photothermal, and photodynamic therapy effect.

Quantum Dots Mediated Imaging and Phototherapy in Cancer Spheroid Models: State of the Art and Perspectives

Quantum Dots (QDs) are fluorescent nanoparticles known for their exceptional optical properties, i.e., high fluorescence emission, photostability, narrow emission spectrum, and broad excitation wavelength. These properties make QDs an exciting choice for bioimaging applications, notably in cancer imaging. Challenges lie in their ability to specifically label targeted cells. Numerous studies have been carried out with QDs coupled to various ligands like peptides, antibodies, aptamers, etc., to achieve efficient targeting. Most studies were conducted in vitro with two-dimensional cell monolayers (n = 8902) before evolving towards more sophisticated models. Three-dimensional multicellular tumor models better recapitulate in vivo conditions by mimicking cell-to-cell and cell-matrix interactions. To date, only few studies (n = 34) were conducted in 3D in vitro models such as spheroids, whereas these models could better represent QDs behavior in tumors compared to monolayers. Thus, the purpose of this review is to present a state of the art on the studies conducted with Quantum Dots on spheroid models for imaging and phototherapy purposes.

Advances in nanobiotechnology-propelled multidrug resistance circumvention of cancer

Multidrug resistance (MDR) is one of the main reasons for the failure of tumor chemotherapy and has a negative influence on the therapeutic effect. MDR is primarily attributable to two mechanisms: the activation of efflux pumps for drugs, which can transport intracellular drug molecules from cells, and other mechanisms not related to efflux pumps, e.g., apoptosis prevention, strengthened DNA repair, and strong oxidation resistance. Nanodrug-delivery systems have recently attracted much attention, showing some unparalleled advantages such as drug targeting and reduced drug efflux, drug toxicity and side effects in reversing MDR. Notably, in drug-delivery platforms based on nanotechnology, multiple therapeutic strategies are integrated into one system, which can compensate for the limitations of individual strategies. In this review, the mechanisms of tumor MDR as well as common vectors and nanocarrier-combined therapy strategies to reverse MDR were summarized to promote the understanding of the latest progress in improving the efficiency of chemotherapy and synergistic strategies. In particular, the adoption of nanotechnology has been highlighted and the principles underlying this phenomenon have been elucidated, which may provide guidance for the development of more effective anticancer strategies.

Research Progress of Photothermal Nanomaterials in Multimodal Tumor Therapy

The aggressive growth of cancer cells brings extreme challenges to cancer therapy while triggering the exploration of the application of multimodal therapy methods. Multimodal tumor therapy based on photothermal nanomaterials is a new technology to realize tumor cell thermal ablation through near-infrared light irradiation with a specific wavelength, which has the advantages of high efficiency, less adverse reactions, and effective inhibition of tumor metastasis compared with traditional treatment methods such as surgical resection, chemotherapy, and radiotherapy. Photothermal nanomaterials have gained increasing interest due to their potential applications, remarkable properties, and advantages for tumor therapy. In this review, recent advances and the common applications of photothermal nanomaterials in multimodal tumor therapy are summarized, with a focus on the different types of photothermal nanomaterials and their application in multimodal tumor therapy. Moreover, the challenges and future applications have also been speculated.

A mutually beneficial macrophages-mediated delivery system realizing photo/immune therapy

The accumulation of nanomedicines in tumor tissues determines their therapeutic efficacy. We herein exploit the tropism of macrophages to improve the accumulation and retention time of nanomedicine at tumors. Interestingly, macrophages are not merely as transporters, but killers activated by nanomedicine. The system(M@C-HA/ICG) was established by decorating macrophages with hyaluronic acid-modified hollow mesoporous carbon (C) nanoparticles loading indocyanine green (ICG). Notably, C nanoparticles with superior photothermal conversion capability not merely guarantee the efficient delivery of ICG through high drug loading efficiency and inhibiting the premature leaky, but effectually activate the polarization of macrophages. The results exhibited that those activated macrophages could release pro-inflammatory cytokines (NO, TNF-α, IL-12), while M@C-HA/ICG afforded about 2-fold higher tumor accumulation compared with pure nanoparticle C-HA/ICG and produced heat and singlet oxygen (¹O₂) under irradiation of an 808 nm laser, realizing the combination of photodynamic therapy (PDT), photothermal therapy (PTT) and cytokines-mediated immunotherapy. Specially, we also investigated the relationship of singlet oxygen (¹O₂) or temperature and tumor-killing activity for understanding the specific effectual procedure of PDT/PTT synergistic therapy. Overall, we firstly established an "all active" delivery system integrating the features of nanomedicine with biological functions of macrophages, providing a novel insight for cell-mediated delivery platform and tumor targeted multimodality anti-cancer therapy.

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.

Stimuli-Responsive Nanoparticles for Controlled Drug Delivery in Synergistic Cancer Immunotherapy

Cancer immunotherapy has achieved promising clinical progress over the recent years for its potential to treat metastatic tumors and inhibit their recurrences effectively. However, low patient response rates and dose-limiting toxicity remain as major dilemmas for immunotherapy. Stimuli-responsive nanoparticles (srNPs) combined with immunotherapy offer the possibility to amplify anti-tumor immune responses, where the weak acidity, high concentration of glutathione, overexpressions of enzymes, and reactive oxygen species, and external stimuli in tumors act as triggers for controlled drug release. This review highlights the design of srNPs based on tumor microenvironment and/or external stimuli to combine with different anti-tumor drugs, especially the immunoregulatory agents, which eventually realize synergistic immunotherapy of malignant primary or metastatic tumors and acquire a long-term immune memory to prevent tumor recurrence. The authors hope that this review can provide theoretical guidance for the construction and clinical transformation of smart srNPs for controlled drug delivery in synergistic cancer immunotherapy.

Supramolecular co-encapsulation of a photosensitizer and chemotherapeutic drug in cucurbit[8]uril for potential chemophototherapy

Supramolecular strategies as well as combinatorial approaches have been proposed to improve cancer therapeutics. In this work, we investigated the encapsulation of the photosensitizer acridine orange (AO) and the chemotherapeutic drug oxaliplatin (OxPt) in cucurbit[8]uril (CB[8]), and tested their effect both separate and combined on tumoral cells cultivated in vitro. Binding constants and enthalpies of reaction for the AO@CB[8], (AO)₂@CB[8] and OxPt@CB[8] complexes were determined by isothermal titration calorimetry. In the case of AO, a negative cooperativity for the binding of the second AO molecule was found, in agreement with previous fluorescence titration data. We show herein that the AO@CB[8] complex was effectively incorporated within the cells and showed important phototoxicity, while the OxPt@CB[8] complex was cytotoxic only at long incubation times (24 h). Pre-treatment of the cells with the OxPt@CB[8] complex for 24 h inhibited any photodynamic action by the later treatment with the AO@CB[8] complex. However, when both complexes were co-incubated for 90 min, the combined cytotoxicity/phototoxicity was superior to any of the treatments individually. A cooperative effect was identified that added up to an extra 30% cytotoxicity/phototoxicity. The results point to an interesting system where a photosensitizer and chemotherapeutic drug are co-encapsulated in a macrocycle to develop chemophototherapy applications.

Carbon dot composites for bioapplications: a review

Recent advancements in the synthesis of carbon dot composites and their applications in biomedical fields (bioimaging, drug delivery and biosensing) have been carefully summarized. The current challenges and future trends of CD composites in this field have also been discussed.

Recent Advances in Functional Carbon Quantum Dots for Antitumour

Carbon quantum dots (CQDs) are an emerging class of quasi-zero-dimensional photoluminescent nanomaterials with particle sizes less than 10 nm. Owing to their favourable water dispersion, strong chemical inertia, stable optical performance, and good biocompatibility, CQDs have become prominent in biomedical fields. CQDs can be fabricated by “top-down” and “bottom-up” methods, both of which involve oxidation, carbonization, pyrolysis and polymerization. The functions of CQDs include biological imaging, biosensing, drug delivery, gene carrying, antimicrobial performance, photothermal ablation and so on, which enable them to be utilized in antitumour applications. The purpose of this review is to summarize the research progress of CQDs in antitumour applications from preparation and characterization to application prospects. Furthermore, the challenges and opportunities of CQDs are discussed along with future perspectives for precise individual therapy of tumours.

Synergistic chemo-photothermal cancer therapy of pH-responsive polymeric nanoparticles loaded IR825 and DTX with charge-reversal property

IR825 is a kind of near-infrared (NIR) small molecule cyanine dye and has distinct near-infrared absorbance and excellent thermal conversion performance. Due to poor stability and insufficient therapy efficacy, various nano-systems have been developed as delivery vehicles for NIR dyes to improve their application in tumor treatment. Herein, we developed an intelligent polymer drug vehicle (Mal-PAH-PEG-DMMA/ poly (ethylene imine) - poly(ε-caprolactone) block polymers, MPPD/PEI-PCL) based on pH-responsive charge-reversal to deliver docetaxel (DTX) and photosensitizer (IR825) for chemo-photothermal combination therapy (MPPD@IR825/DTX NPs). MPPD@IR825/DTX NPs could undergo charge conversion in a slightly acidic microenvironment (pH 6.8), resulted in strong electrostatic repulsion to withdraw the shell of the polymer nanoparticles (MPPD), enhanced cellular uptake and increased drug release. MPPD@IR825/DTX NPs demonstrated nanoscale in size with good mono-dispersity and stability, triggered DTX release in response to acid environment and NIR stimulation, in the same time providing excellent photothermal conversion efficiency. In vitro and In vivo experiments confirmed that charge-reversal polymeric nanoparticles improved antitumor efficiency in 4T1 tumor cell modal than non-charge-reversal polymeric nanoparticles. Furthermore, in comparison with chemotherapy or photothermal therapy in a single treatment mode, chemo-photothermal combination therapy of MPPD@IR825/DTX NPs with laser irradiation showed highly efficient tumor ablation. In addition, the polymeric nanoparticles exhibited good biocompatibility and safety. Therefore, the design of charge-reversal polymeric nanoparticles (MPPD@IR825/DTX NPs) provides a new strategy and promising application for targeting and synergistic chemo-photothermal combination therapy.

Fluorescent carbon dots embedded in mesoporous silica nanospheres: A simple platform for Cr(VI) detection in environmental water

In this work, amino-functionalized mesoporous silica nanospheres (NH₂-mSiO₂) anchored with carbon dots (CDs) have been designed to construct an outstanding fluorescent sensor for heavy metal detection. Uniform mSiO₂ was chosen to provide an optically transparent scaffold for immobilizing CDs. With the help of amino group modification on the surface of silica, benzene-1,4-diboronic acid (BA) was used as raw material to load CDs in the pores of mSiO₂ by one-step solvothermal method. The proposed nanohybrid can solve the problem of aggregation-induced fluorescence quenching, leading to bright blue emission at 450 nm. Meanwhile, the fluorescence of NH₂-mSiO₂@CDs showed high sensitivity to Cr(VI) in acetic acid buffer solution (pH = 4) with detection limit as low as 5 nM by inner filter effect (IFE) and electrostatic interaction (EI). The proposed method can also be extended to other CDs-based detection systems for chemical/biological sensors.

CoFe2O4-Quantum Dots for Synergistic Photothermal/Photodynamic Therapy of Non-small-Cell Lung Cancer Via Triggering Apoptosis by Regulating PI3K/AKT Pathway

Non-small-cell lung cancer (NSCLC) has become the second most diagnosed malignant tumors worldwide. As our long-term interests in seeking nanomaterials to develop strategies of cancer therapies, we herein constructed novel CoFe2O4-quantum dots (QDs) with outstanding synergistic photothermal/photodynamic property which suppressed NSCLC efficiently without apparent toxicity. We showed that the combination of CoFe2O4-QDs + NIR treatment induces apoptosis of NSCLC cells. In addition, the CoFe2O4-QDs + NIR treatment also promotes reactive oxygen species generation to trigger cell death through regulating PI3K/AKT pathway. Moreover, the CoFe2O4-QDs + NIR treatment successfully eliminates tumor xenografts in vivo without apparent toxic effects. Taken together, we reported that the novel nanomaterials CoFe2O4-QDs could exhibit enhanced synergistic photothermal therapy and photodynamic therapy effect on killing NSCLC without toxicity, which could be a promising photosensitizer for NSCLC therapy.

A versatile gas-generator promoting drug release and oxygen replenishment for amplifying photodynamic-chemotherapy synergetic anti-tumor effects

Excellent efficiency of combinational therapy of chemotherapy and photodynamic therapy (PDT) highly depends on the amounts of drug and oxygen in tumor tissue. However, how to cleverly promote drug release accompanied with improving oxygen concentration remains a challenge. Herein, we proposed a gas-generator that realized a high drug loading and integrated facilitation of drug release with oxygen replenishment into a single and simple system, utilizing huge cavities and mesoporous channels of hollow mesoporous silica nanoparticles (HMSNs) for encapsulating oxygen (O₂) saturated perfluoropentane (PFP) droplets, indocyanine green (ICG) and doxorubicin (DOX), biocompatible polydopamine (PDA) as the gatekeepers. Under irradiation of 808 nm laser, the thermal effect of PDA caused PFP droplets occur liquid-gas phase transition that triggered the burst release of DOX and O₂, finally amplifying the synergetic effects of PDT and chemotherapy both in vitro and in vivo. The influence of PFP, GSH and laser on drug release kinetic was explored through mathematical models. Notably, the mechanism of gas-generator on accelerating drug release under irradiation based on doing volume work and enhancing diffusion coefficient was clarified by researching the relation between DOX release, PFP release and temperature change. Additionally, the way of replenishing O₂ did not rely on intracellular components but timely offered abundant "fuels" for producing reactive oxygen species (ROS) when compared with traditional manners. This work provides a new research strategy for boosting drug release and opens an avenue for constructing multifunctional controlled delivery systems.

Carbon Dots: An Emerging Smart Material for Analytical Applications

Carbon dots (CDs) are optically active carbon-based nanomaterials. These nanomaterials can change their light emission properties in response to various external stimuli such as pH, temperature, pressure, and light. The CD's remarkable stimuli-responsive smart material properties have recently stimulated massive research interest for their exploitation to develop various sensor platforms. Herein, an effort has been made to review the major advances made on CDs, focusing mainly on its smart material attributes and linked applications. Since the CD's material properties are largely linked to their synthesis approaches, various synthesis methods, including surface passivation and functionalization of CDs and the mechanisms reported so far in their photophysical properties, are also delineated in this review. Finally, the challenges of using CDs and the scope for their further improvement as an optical signal transducer to expand their application horizon for developing analytical platforms have been discussed.

Synergic effects of nanoparticles-mediated hyperthermia in radiotherapy/chemotherapy of cancer

The conventional cancer treatment modalities such as radiotherapy and chemotherapy suffer from several limitations; hence, their efficiency needs to be improved with other complementary modalities. Hyperthermia, as an adjuvant therapeutic modality for cancer, can result in a synergistic effect on radiotherapy (radiosensitizer) and chemotherapy (chemosensitizer). Conventional hyperthermia methods affect both tumoral and healthy tissues and have low specificity. In addition, a temperature gradient generates in the tissues situated along the path of the heat source, which is a more serious for deep-seated tumors. Nanoparticles (NPs)-induced hyperthermia can resolve these drawbacks through localization around/within tumoral tissue and generating local hyperthermia. Although there are several review articles dealing with NPs-induced hyperthermia, lack of a paper discussing the combination of NPs-induced hyperthermia with the conventional chemotherapy or radiotherapy is tangible. Accordingly, the main focus of the current paper is to summarize the principles of NPs-induced hyperthermia and more importantly its synergic effects on the conventional chemotherapy or radiotherapy. The heat-producing nanostructures such as gold NPs, iron oxide NPs, and carbon NPs, as well as the non-heat-producing nanostructures, such as lipid-based, polymeric, and silica-based NPs, as the carrier for heat-producing NPs, are discussed and their pros and cons highlighted.

Synthesis of Multi-Functional Carbon Quantum Dots for Targeted Antitumor Therapy

Carbon dots are nano-sized photoluminescence materials which have good biocompatibility and low cytotoxicity, while the previously synthesized carbon dots lack tumor targeting capability and therapy function so that it cannot achieve the purpose of diagnosis and treatment. Herein, a new kind of multi-functional carbon dots (GFCDs) is promising to be applied in tumor cells imaging and clinical targeted therapy. Gallic acid (GA) was used as the carbon resource and antitumor active molecule, folic acid (FA) was used as the nitrogen resource and tumor targeting molecule, and citric acid monohydrate (CA) was used as the auxiliary carbon source. Multi-functional GACDs were synthesized by a simple one-step microwave-assisted procedure and analyzed with UV - vis spectrophotometer, fourier transform infrared spectrometer, transmission electron microscopy and X-ray photoelectron spectrometer. Results show that the diameter of GFCDs is about 3 nm. And GFCDs are pale-yellow under natural light which turn blue under 360 nm UV lamp. Besides ester bond is the connecting mode between functional molecules. In addition, the results of in vitro cell imaging experiments and in vivo antitumor experiments demonstrate the targeting imaging and antitumor abilities towards Hela cells. The synthesis route and properties of GFCDs.

Carbon Dots as Nanotherapeutics for Biomedical Application

Carbon nanodots are zero-dimensional spherical allotropes of carbon and are less than 10nm in size (ranging from 2-8nm). Based on their biocompatibility, remarkable water solubility, eco- friendliness, conductivity, desirable optical properties and low toxicity, carbon dots have revolutionized the biomedical field. In addition, they have intrinsic photo-luminesce to facilitate bio-imaging, bio-sensing and theranostics. Carbon dots are also ideal for targeted drug delivery. Through functionalization of their surfaces for attachment of receptor-specific ligands, they ultimately result in improved drug efficacy and a decrease in side-effects. This feature may be ideal for effective chemo-, gene- and antibiotic-therapy. Carbon dots also comply with green chemistry principles with regard to their safe, rapid and eco-friendly synthesis. Carbon dots thus, have significantly enhanced drug delivery and exhibit much promise for future biomedical applications. The purpose of this review is to elucidate the various applications of carbon dots in biomedical fields. In doing so, this review highlights the synthesis, surface functionalization and applicability of biodegradable polymers for the synthesis of carbon dots. It further highlights a myriad of biodegradable, biocompatible and cost-effective polymers that can be utilized for the fabrication of carbon dots. The limitations of these polymers are illustrated as well. Additionally, this review discusses the application of carbon dots in theranostics, chemo-sensing and targeted drug delivery systems. This review also serves to discuss the various properties of carbon dots which allow chemotherapy and gene therapy to be safer and more target-specific, resulting in the reduction of side effects experienced by patients and also the overall increase in patient compliance and quality of life.

Recent Advances in Nanomaterials-Based Chemo-Photothermal Combination Therapy for Improving Cancer Treatment

Conventional chemotherapy for cancer treatment is usually compromised by shortcomings such as insufficient therapeutic outcome and undesired side effects. The past decade has witnessed the rapid development of combination therapy by integrating chemotherapy with hyperthermia for enhanced therapeutic efficacy. Near-infrared (NIR) light-mediated photothermal therapy, which has advantages such as great capacity of heat ablation and minimally invasive manner, has emerged as a powerful approach for cancer treatment. A variety of nanomaterials absorbing NIR light to generate heat have been developed to simultaneously act as carriers for chemotherapeutic drugs, contributing as heat trigger for drug release and/or inducing hyperthermia for synergistic effects. This review aims to summarize the recent development of advanced nanomaterials in chemo-photothermal combination therapy, including metal-, carbon-based nanomaterials and particularly organic nanomaterials. The potential challenges and perspectives for the future development of nanomaterials-based chemo-photothermal therapy were also discussed.

Triple stimuli-responsive ZnO quantum dots-conjugated hollow mesoporous carbon nanoplatform for NIR-induced dual model antitumor therapy

Aiming at the inefficiency and toxicity in traditional antitumor therapy, a novel multifunctional nanoplatform was constructed based on hollow mesoporous carbon (HMC) to achieve triple stimuli response and dual model antitumor therapy via chemo-photothermal synergistic effect. HMC was used as an ideal nanovehicle with a high drug loading efficiency as well as a near-infrared (NIR) photothermal conversion agent for photothermal therapy. Acid-dissoluble, luminescent ZnO quantum dots (QDs) were used as the proper sealing agents for the mesopores of HMC, conjugated to HMC via disulfide linkage to prevent drug (doxorubicin, abbreviated as Dox) premature release from Dox/HMC-SS-ZnO. After cellular endocytosis, the Dox was released in a pH, GSH and NIR laser triple stimuli-responsive manner to realize accurate drug delivery. Moreover, the local hyperthermia effect induced by NIR irradiation could promote the drug release, enhance cell sensitivity to chemotherapeutic agents, and also directly kill cancer cells. As expected, Dox/HMC-SS-ZnO exhibited a high drug loading capacity of 43%, well response to triple stimuli and excellent photothermal conversion efficiency η of 29.7%. The therapeutic efficacy in 4T1 cells and multicellular tumor spheroids (MCTSs) demonstrated that Dox/HMC-SS-ZnO + NIR had satisfactory chemo-photothermal synergistic effect with a combination index (CI) of 0.532. The cell apoptosis rate of the combined treatment group was more than 95%. The biodistribution and pharmacodynamics studies showed its biosecurity to normal tissues and synergistic inhibition effect to tumor cells. These distinguished results indicated that the Dox/HMC-SS-ZnO nanoplatform is potential to realize efficient triple stimuli-responsive drug delivery and dual model chemo-photothermal synergistic antitumor therapy.