A bioinspired doxorubicin-carried albumin Nanocage against aggressive Cancer via systemic targeting of tumor and lymph node metastasis

Cancer metastasis and recurrence are obstacles to successful treatment of aggressive cancer. To address this challenge, chemotherapy is indispensable as an essential part of comprehensive cancer treatment, particularly for subsequent therapy after surgical resection. However, small-molecule drugs for chemotherapy always cause inadequate efficacy and severe side effects against cancer metastasis and recurrence caused by lymph node metastases. Here, we developed doxorubicin-carried albumin nanocages (Dox-AlbCages) with appropriate particle sizes and pH/enzyme-responsive drug release for tumor and lymph node dual-targeted therapy by exploiting the inborn transport properties of serum albumin. Inspired by the protein-templated biomineralization and remote loading of doxorubicin into liposomes, we demonstrated the controlled synthesis of Dox-AlbCages via the aggregation or crystallization of doxorubicin and ammonium sulfate within albumin nanocages using a biomineralization strategy. Dox-AlbCages allowed efficient encapsulation of Dox in the core protected by the albumin corona shell, exhibiting favorable properties for enhanced tumor and lymph node accumulation and preferable cellular uptake for tumor-specific chemotherapy. Intriguingly, Dox-AlbCages effectively inhibited tumor growth and metastasis in orthotopic 4T1 breast tumors and prevented postsurgical tumor recurrence and lung metastasis. At the same time, Dox-AlbCages had fewer side effects than free Dox. This nanoplatform provides a facile strategy for designing tumor- and lymph node-targeted nanomedicines for suppressing cancer metastasis and recurrence.

Mechanistic Insights of Neuroprotective Efficacy of Verapamil-Loaded Carbon Quantum Dots against LPS-Induced Neurotoxicity in Rats

Alzheimer's disease (AD) is a neurodegenerative disease that badly impacts patients and their caregivers. AD is characterized by deposition of amyloid beta (Aβ) and phosphorylated tau protein (pTau) in the brain with underlying neuroinflammation. We aimed to develop a neuroprotective paradigm by loading verapamil (VRH) into hyaluronic acid-modified carbon quantum dots (CQDs) and comparing its effectiveness with the free form in an AD-like model in rats induced by lipopolysaccharide (LPS). The experimental rats were divided into seven groups: control, LPS, CQDs, early free VRH (FVRH), late FVRH, early verapamil carbon quantum dots (VCQDs), and late VCQDs. Characterizations of VCQDs, the behavioral performance of the rats, histopathological and immunohistochemical changes, some AD hallmarks, oxidative stress biomarkers, neuro-affecting genes, and DNA fragmentation were determined. VRH was successfully loaded into CQDs, which was confirmed by the measured parameters. VRH showed enhancement in cognitive functions, disruption to the architecture of the brain, decreased Aβ and pTau, increased antioxidant capacity, modifiable expression of genes, and a decline in DNA fragmentation. The loaded therapy was superior to the free drug. Moreover, the early intervention was better than the late, confirming the implication of the detected molecular targets in the development of AD. VRH showed multifaceted mechanisms in combating LPS-induced neurotoxicity through its anti-inflammatory and antioxidant properties, thereby mitigating the hallmarks of AD. Additionally, the synthesized nanosystem approach exhibited superior neuroprotection owing to the advantages offered by CQDs. However, finding new actionable biomarkers and molecular targets is of decisive importance to improve the outcomes for patients with AD.

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.

A review on multifaceted biomedical applications of heparin nanocomposites: Progress and prospects

Advances in polymer-based nanocomposites have revolutionized biomedical applications over the last two decades. Heparin (HP), being a highly bioactive polymer of biological origin, provides strong biotic competence to the nanocomposites, broadening the horizon of their applicability. The efficiency, biocompatibility, and biodegradability properties of nanomaterials significantly improve upon the incorporation of heparin. Further, inclusion of structural/chemical derivatives, fractionates, and mimetics of heparin enable fabrication of versatile nanocomposites. Modern nanotechnological interventions have exploited the inherent biofunctionalities of heparin by formulating various nanomaterials, including inorganic/polymeric nanoparticles, nanofibers, quantum dots, micelles, liposomes, and nanogels ensuing novel functionalities targeting diverse clinical applications involving drug delivery, wound healing, tissue engineering, biocompatible coatings, nanosensors and so on. On this note, the present review explicitly summarises the recent HP-oriented nanotechnological developments, with a special emphasis on the reported successful engagement of HP and its derivatives/mimetics in nanocomposites for extensive applications in the laboratory and health-care facility. Further, the advantages and limitations/challenges specifically associated with HP in nanocomposites, undertaken in this current review are quintessential for future innovations/discoveries pertaining to HP-based nanocomposites.

Tumor diagnosis using carbon-based quantum dots: Detection based on the hallmarks of cancer

Carbon-based quantum dots (CQDs) have been shown to have promising application value in tumor diagnosis. Their use, however, is severely hindered by the complicated nature of the nanostructures in the CQDs. Furthermore, it seems impossible to formulate the mechanisms involved using the inadequate theoretical frameworks that are currently available for CQDs. In this review, we re-consider the structure-property relationships of CQDs and summarize the current state of development of CQDs-based tumor diagnosis based on biological theories that are fully developed. The advantages and deficiencies of recent research on CQDs-based tumor diagnosis are thus explained in terms of the manifestation of nine essential changes in cell physiology. This review makes significant progress in addressing related problems encountered with other nanomaterials.

Revolutionizing Cancer Care: Advances in Carbon-Based Materials for Diagnosis and Treatment

Cancer involves intricate pathological mechanisms marked by complexities such as cytotoxicity, drug resistance, stem cell proliferation, and inadequate specificity in current chemotherapy approaches. Cancer therapy has embraced diverse nanomaterials renowned for their unique magnetic, electrical, and optical properties to address these challenges. Despite the expanding corpus of knowledge in this area, there has been less advancement in approving nano drugs for use in clinical settings. Nanotechnology, and more especially the development of intelligent nanomaterials, has had a profound impact on cancer research and treatment in recent years. Due to their large surface area, nanoparticles can adeptly encapsulate diverse compounds. Furthermore, the modification of nanoparticles is achievable through a broad spectrum of bio-based substrates, including DNA, aptamers, RNA, and antibodies. This functionalization substantially enhances their theranostic capabilities. Nanomaterials originating from biological sources outperform their conventionally created counterparts, offering advantages such as reduced toxicity, lower manufacturing costs, and enhanced efficiency. This review uses carbon nanomaterials, including graphene-based materials, carbon nanotubes (CNTs) based nanomaterials, and carbon quantum dots (CQDs), to give a complete overview of various methods used in cancer theranostics. We also discussed their advantages and limitations in cancer diagnosis and treatment settings. Carbon nanomaterials might significantly improve cancer theranostics and pave the way for fresh tumor diagnosis and treatment approaches. More study is needed to determine whether using nano-carriers for targeted medicine delivery may increase material utilization. More insight is required to explore the correlation between heightened cytotoxicity and retention resulting from increased permeability.

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.

Application of green-synthesized carbon dots for imaging of cancerous cell lines and detection of anthraquinone drugs using silica-coated CdTe quantum dots-based ratiometric fluorescence sensor

Chemotherapy drugs of daunorubicin and doxorubicin treat cancers with many side effects. So, detection of them in the biological system for regulation and controlling of usage is essential. In this study, a ratiometric fluorescent method was introduced for detection of daunorubicin and doxorubicin using bell pepper-based carbon dots, as the variable signal, and silica-coated CdTe quantum dots, as the constant signal. The detection was done based on variations of carbon dots intensity in the presence of drugs in comparison with the constant intensity of silica-coated CdTe quantum dots. The proposed ratiometric fluorescent method was successfully used for detection of daunorubicin and doxorubicin range of 54.37-13594.34 nmolL^-1 and 86.2-17242 nmolL^-1, with a detection limit of 18.53 nmolL^-1 and 29 nmolL^-1, respectively. Also, this method was used for detection of drugs in serum samples with recovery ranges of 86.14-99.62 (RSD 3-1.47%) and 86.32-97.53 (3.38-1.48%), respectively. Finally, after evaluation of carbon dots toxicity by MTT test, carbon dots was applied for imaging of prostate cancer cell lines (PC-3) and breast cancer cell lines (MCF7). The results demonstrated that despite improvement of the repeatability and interferences reduction by ratiometric method, also carbon dots were successfully applied for imaging of cell lines.

A brief review on the synthesis, characterisation and analytical applications of nitrogen doped carbon dots

Since their discovery in 2004, fluorescent carbon nanoparticles have been tremendously studied due to their tunable optical properties. Recent studies on the synthesis and application of doped carbon dots highlight the effortless doping strategy with high quantum yields and applications in diverse fields. Among these, nitrogen doped carbon dots (NCDs) have been extensively investigated for their potential analytical and biological applications. This review features the synthetic methods and important characterisation studies required to verify successful synthesis of nitrogen doped carbon dots. Analytical applications of NCDs in metal ion, biomolecule, temperature, pH and gas sensing along with cell imaging and drug delivery applications are also discussed.

Lipid Status of A2780 Ovarian Cancer Cells after Treatment with Ruthenium Complex Modified with Carbon Dot Nanocarriers: A Multimodal SR-FTIR Spectroscopy and MALDI TOF Mass Spectrometry Study

Simple Summary

Developing new anticancer medicaments is focused on inducing controlled elimination of tumor tissue without severe side effects. It is essential to enable the medicament to reach the target molecule without provoking the immune response too early. The first cellular changes might occur already at the level of the cell membrane, composed mainly of lipids. Therefore, we used spectroscopic techniques to study the interaction of potential metallodrug [Ru(η⁵-C₅H₅)(PPh₃)₂CN] (RuCN) with lipids of A2780 ovarian cancer cells and investigated if these changes are affected by the presence of drug carriers (carbon dots (CDs) and nitrogen-doped carbon dots (N-CDs)). Our results showed that CDs and N-CDs prevent lysis and moderate oxidative stress of lipids caused by metallodrug, still keeping the antitumor activity and potential to penetrate through the lipid bilayer. Therefore, Ru drug loading to carriers balances the anticancer efficiency and leads to better anticancer outcomes by reducing the oxidative stress that has been linked to cancer progression.

Abstract

In the last decade, targeting membrane lipids in cancer cells has been a promising approach that deserves attention in the field of anticancer drug development. To get a comprehensive understanding of the effect of the drug [Ru(η⁵-Cp)(PPh₃)₂CN] (RuCN) on cell lipidic components, we combine complementary analytical approaches, matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI TOF MS) and synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectroscopy. Techniques are used for screening the effect of potential metallodrug, RuCN, without and with drug carriers (carbon dots (CDs) and nitrogen-doped carbon dots (N-CDs)) on the lipids of the human ovarian cancer cell line A2780. MALDI TOF MS results revealed that the lysis of ovarian cancer membrane lipids is promoted by RuCN and not by drug carriers (CDs and N-CDs). Furthermore, SR-FTIR results strongly suggested that the phospholipids of cancer cells undergo oxidative stress after the treatment with RuCN that was accompanied by the disordering of the fatty acid chains. On the other hand, using (N-)CDs as RuCN nanocarriers prevented the oxidative stress caused by RuCN but did not prevent the disordering of the fatty acid chain packing. Finally, we demonstrated that RuCN and RuCN/(N-)CDs alter the hydration of the membrane surface in the membrane–water interface region.

Green Nanotechnology: Plant-Mediated Nanoparticle Synthesis and Application

The key pathways for synthesizing nanoparticles are physical and chemical, usually expensive and possibly hazardous to the environment. In the recent past, the evaluation of green chemistry or biological techniques for synthesizing metal nanoparticles from plant extracts has drawn the attention of many researchers. The literature on the green production of nanoparticles using various metals (i.e., gold, silver, zinc, titanium and palladium) and plant extracts is discussed in this study. The generalized mechanism of nanoparticle synthesis involves reduction, stabilization, nucleation, aggregation and capping, followed by characterization. During biosynthesis, major difficulties often faced in maintaining the structure, size and yield of particles can be solved by monitoring the development parameters such as temperature, pH and reaction period. To establish a widely accepted approach, researchers must first explore the actual process underlying the plant-assisted synthesis of a metal nanoparticle and its action on others. The green synthesis of NPs is gaining attention owing to its facilitation of the development of alternative, sustainable, safer, less toxic and environment-friendly approaches. Thus, green nanotechnology using plant extract opens up new possibilities for the synthesis of novel nanoparticles with the desirable characteristics required for developing biosensors, biomedicine, cosmetics and nano-biotechnology, and in electrochemical, catalytic, antibacterial, electronics, sensing and other 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.

Heparin detection based on the fluorescent turn-on probe of amino carbon quantum dots

Amino-rich carbon quantum dots (CDs) were synthesized by hydrothermal treatment of ethylene glycol, glucose and polyethyleneimine. CDs have green fluorescence (excitation/emission peaks 435 nm/515 nm) and can be enhanced by the addition of heparin (Hep). A linear relationship between fluorescence intensity and heparin concentration was observed. The fluorescence turn-on probe used for Hep detection showed a very large detection range of 0.02-16 μM, covering different therapeutic ranges in clinical applications. The probe exhibited an ultra-low detection limit of 0.007 nM.

The synthesis and efficiency investigation of a boronic acid-modified magnetic chitosan quantum dot nanocomposite in the detection of Cu2+ ions

We prepared the magnetic chitosan carbon quantum dot nanoparticles (Fe₃O₄@CQD NPs) via the hydrothermal treatment of chitosan biopolymer and then its magnetization with Fe₃O₄ nanoparticles. (4-Acetylphenyl)boronic acid compound was utilized for the modification of surface of Fe₃O₄@CQD nanoparticles via the covalent imine bond formation between NH₂ groups of chitosan quantum dot with carbonyl functional of acetyl-substituted arylboronic acid. The synthesized Fe₃O₄@CQD@AP-B(OH)₂ was characterized by FE-SEM, EDS, XRD, VSM and ICP-OES analysis and its fluorescence property was studied. This magnetic multifunctional nanoplatform sensor has shown high potential sensitivity for Cu²⁺ ions (in the range of 1.0-30.0 μM with limit of detection 0.3 μM) through interaction of cupric ions with the boronic-acid moiety.

Biomimetic camouflage delivery strategies for cancer therapy

Cancer remains a significant challenge despite the progress in developing different therapeutic approaches. Nanomedicine has been explored as a promising novel cancer therapy. Recently, biomimetic camouflage strategies have been investigated to change the bio-fate of therapeutics and target cancer cells while reducing the unwanted exposure on normal tissues. Endogenous components (e.g., proteins, polysaccharides, and cell membranes) have been used to develop anticancer drug delivery systems. These biomimetic systems can overcome biological barriers and enhance tumor cell-specific uptake. The tumor-targeting mechanisms include ligand-receptor interactions and stimuli-responsive (e.g., pH-sensitive and light-sensitive) delivery. Drug delivery carriers composed of endogenous components represent a promising approach for improving cancer treatment efficacy. In this paper, different biomimetic drug delivery strategies for cancer treatment are reviewed with a focus on the discussion of their advantages and potential applications.

Cytotoxicity and cell imaging of six types of carbon nanodots prepared through carbonization and hydrothermal processing of natural plant materials

In this study we prepared six types of carbon nanodots (CNDs) from natural plant materials – through carbonization of two species of bamboo (Bamboo-I, Bamboo-II) and one type of wood (Wood), and through hydrothermal processing of the stem and root of the herb Mahonia oiwakensis Hayata (MO) and of the agricultural waste of two species of pineapple root (PA, PB). The resulting CNDs were spherical with dimensions on the nanoscale (3–7 nm); furthermore, CND-Bamboo I, CND-Wood, CND-Bamboo II, CND-MO, CND-PA, and CND-PB displayed fluorescence quantum yields of 9.63, 12.34, 0.90, 10.86, 0.35, and 0.71%, respectively. X-ray diffraction revealed that the carbon nanostructures possessed somewhat ordered and disordered lattices, as evidenced by broad signals at values of 2θ between 20 and 30°. CND-Bamboo I, CND-Wood, and CND-Bamboo II were obtained in yields of 2–3%; CND-MO, CND-PA, and CND-PB were obtained in yields of 17.64, 9.36, and 22.47%, respectively. Cytotoxicity assays for mouse macrophage RAW264.7 cells treated with the six types of CNDs and a commercial sample of Ag nanoparticles (NPs) revealed that each of our CNDs provided a cell viability of 90% at 2000 μg mL⁻¹, whereas it was only 20% after treatment with the Ag NPs at 62.5 μg mL⁻¹. The six types of CNDs also displayed low cytotoxicity toward human keratinocyte HacaT cells, human MCF-7 breast cancer cells, and HT-29 colon adenocarcinoma cells when treated at 500 μg mL⁻¹. Moreover, confocal microscopic cell imaging revealed that the fluorescent CND-Bamboo I particles were located on the MCF-7 cell membrane and inside the cells after treatment for 6 and 24 h, respectively. We have thoroughly investigated the photoluminescence properties and carbon nanostructures of these highly dispersed CNDs. Because of the facile green synthesis of these six types of CNDs and their sourcing from abundant natural plants, herbs, and agriculture waste, these materials provide a cost-effective method, with low cytotoxicity and stable fluorescence, for biolabeling and for developing cell nanocarriers.

Green nanotechnology of six types of carbon nanodots (CNDs), and their sourcing from abundant natural plants, herbs, and agriculture waste, provides a cost-effective method, with low cytotoxicity and stable fluorescence, for biolabeling and for developing cell nanocarriers.

pH and redox dual-sensitive drug delivery system constructed based on fluorescent carbon dots

Herein, a pH and redox dual-responsive drug delivery system (CDs-Pt(iv)-PEG) was developed based on fluorescence carbon dots (CDs). In this system, cisplatin(iv) prodrug (Pt(iv)) was selected as a model drug to reduce toxic side effects. The aldehyde-functionalized monomethoxy polyethylene glycol (mPEG-CHO) was conjugated to CDs-Pt(iv) to form pH sensitive benzoic imine bond. Owing to the slightly acidic tumor extracellular microenvironment (pH 6.8), the benzoic imine bond was then hydrolyzed, leading to charge reversal and decrease in the hydration radius of the drug-carrying, which facilitated in vivo circulation and tumor targeting. Notably, the cytotoxicity of the drug delivery system on cancer cells was comparable to that of cisplatin, while the side effects on normal cells were significantly reduced. In addition, the system realized recognition of cancer cells by the high-contrast fluorescent imaging. In conclusion, the CDs-Pt(iv)-PEG system provided a promising potential for effective delivery of anticancer drugs and cancer cells screening.

Antitumoral Drug: Loaded Hybrid Nanocapsules Based on Chitosan with Potential Effects in Breast Cancer Therapy

Cancer remains one of the world's most devastating diseases and is responsible for more than 20% of all deaths. It is defined as uncontrolled proliferation of cells and spreads rapidly to healthy tissue. Controlled drug delivery systems offers great opportunities for the development of new non-invasive strategies for the treatment of cancers. The main advantage of these systems is their capacity to accumulate in tumors via enhanced permeability and retention effects. In the present study, an innovative hybrid drug delivery system based on nanocapsules obtained from the interfacial condensation between chitosan and poly(N-vinyl pyrrolidone-alt-itaconic anhydride) and containing both magnetic nanoparticles and an antitumoral drug was developed in order to improve the efficiency of the antitumoral treatment. Using dynamic light scattering, it was observed that the mean diameter of these hybrid nanocapsules was in the range of 43 to 142 nm. SEM confirmed their nanometric size and their well-defined spherical shape. These nanocapsules allowed the encapsulation of an increased amount of 5-fluorouracil and provided controlled drug release. In vitro studies have revealed that these drug-loaded hybrid nanocapsules were able to induce a cytostatic effect on breast carcinoma MCF-7 cell lines (Human Caucasian breast adenocarcinoma - HTB-22) comparable to that of the free drug.

Enhanced-fluorescent imaging and targeted therapy of liver cancer using highly luminescent carbon dots-conjugated foliate

Carbon dots (CDs) have shown great potential in drug delivery and biological imaging applications. In this work, a doxorubicin (DOX) delivery carrier and imaging probe for liver cancer-targeted therapy was designed based on CDs with high fluorescence quantum yield (97%), aiming to enhance the antitumor activity and imaging efficiency. Folic acid (FA), which showed high expression in hepatoma cells, was used as targeting components to modify CDs (FA-CDs), and then FA-CDs-DOX was obtained by loading DOX. Results show that CDs and FA-CDs have good biocompatibility, and the DOX release from FA-CDs-DOX is targeted and selective. Confocal microscope demonstrates that FA-CDs-DOX has excellent ability of fluorescence imaging in liver cancer cells. The imaging in vivo shows the fluorescence intensity of FA-CDs-DOX is strong enough to penetrate tumor tissue and skin, further verifying its enhanced-fluorescent imaging effects. Tumor inhibition in vivo indicates that the targeting ability of FA-CDs-DOX is significantly higher than that of free DOX, showing obvious better therapeutic effect. To sum up, the targeted and fluorescent drug delivery system based on CDs with high fluorescence quantum yield show an excellent imaging in vivo and tumor inhibition effect, which provide a novel strategy for promoting the potential clinical application of CDs in liver cancer treatment.

Protein-Carbon Dot Nanohybrid-Based Early Blood-Brain Barrier Damage Theranostics

For effective treatment of ischemic cerebral thrombosis, it is of great significance to find a facile way in assessing the early damage of blood-brain barrier (BBB) after ischemic stroke during thrombolysis by integrating thrombolytic agents with fluorescent materials. Herein, a novel type of protein-carbon dot  nanohybrids is reported by the incorporation of carbon dots on thrombolytic agents through covalent linkage. Both in vitro and ex vivo fluorescence imaging measurements have demonstrated remarkable imaging effects in the brain of transient middle cerebral artery occlusion mice. Besides, the outstanding thrombolytic capacity of the nanohybrids was determined by in vitro thrombolysis tests. As one of the few reports of the construction of thrombolytic agents and fluorescent nanomaterials, the nanohybrids retain thrombolysis ability and fluorescent traceability simultaneously. It may provide a promising indicator for early BBB damage and thrombolytic agent distribution to estimate the possibility of symptomatic intracranial hemorrhage after thrombolysis and supply tissue window evidence for clinical thrombolytic agent application.

pH-induced aggregation of hydrophilic carbon dots for fluorescence detection of acidic amino acid and intracellular pH imaging

Intracellular pH level plays an important role in physiological and pathological processes. The development of nanoprobes for detecting in vivo pH levels is especially important for early diagnosis of disease. Therefore, we develop a hydrophilic carbon points (CDs) using quercetin and ethylenediamine as precursors to monitor intracellular pH. Under optimized conditions, the prepared CDs not only have uniform particle size and morphology, but also possess strong green fluorescence, photostability, and photoreversibility in water medium. The CDs exhibit pH-sensitive fluorescence effect under acidic and alkaline conditions, which is used to achieve "off-on-off" detection pH (from 3.5 to 13.5). Meanwhile, the pH-dependent mechanism is further investigated and explained, which is the fluorescence quenching caused by the pH-induced aggregation. Based on the pH-sensitive characteristics of CDs, it has been applied to the detection of aspartic acid and glutamic acid. More importantly, when applied to live cells, the pH-probe exhibits low cytotoxicity and high sensitivity, and is successfully used in intracellular pH fluorescence imaging. Consequently, this nanoprobe is expected to be used for real-time monitoring of intracellular pH level.

A novel theranostic system of AS1411 aptamer-functionalized albumin nanoparticles loaded on iron oxide and gold nanoparticles for doxorubicin delivery

Recently DNA aptamers have attracted remarkable attention as possible targeting ligands since selective targeting of cancer cells is a critical step in cancer diagnosis and therapy. Here, the development of AS1411 aptamer-functionalized albumin nanoparticles loaded on iron oxide and gold nanoparticles is reported for target delivery of the well-known anticancer drug of doxorubicin (Dox). Iron oxide nanoparticles (IONPs) and gold nanoparticles (GNPs) were prepared by ultrasound-assisted and controlled seeded growth synthetic methods, respectively. The nanocarrier was synthesized by a desolvation cross-linking method and characterized by dynamic light scattering, zeta potential measurement, thermogravimetric analysis, transmission electron microscopy, as well as vibrating sample magnetometer. The synthesized nanoparticles were found to be spherical with an average diameter of 120 nm and zeta potential of about -50.3 mV. The in-vitro anti-tumor effect of the designed delivery vehicle on MCF7 and SKBR3 human cancer cells was evaluated by MTT assay. The experimental results revealed that it could significantly inhibit the proliferation of cancerous cells. Moreover, GNPs and IONPs with the coating of albumin did not show any toxicity. AS1411 aptamer-functionalized nanoparticles improved cellular uptake and efficiency to MCF7 breast cancer cells as compared to non-targeting nanoparticles because of the high affinity of mentioned aptamer toward the overexpressed nucleolin on MCF7 cell surface.

Carbon quantum dots and their biomedical and therapeutic applications: a review

In recent years, nano carbon quantum dots (CQDs) have received increasing attention due to their properties such as small size, fluorescence emission, chemical stability, water solubility, easy synthesis, and the possibility of functionalization. CQDs are fluorescent 0D carbon nanostructures with sizes below 10 nm. The fluorescence in CQDs originates from two sources, the fluorescence emission from bandgap transitions of conjugated π-domains and fluorescence from surface defects. The CQDs can emit fluorescence in the near-infrared (NIR) spectral region which makes them appropriate for biomedical applications. The fluorescence in these structures can be tuned with respect to the excitation wavelength. The CQDs have found applications in different areas such as biomedicine, photocatalysis, photosensors, solar energy conversion, light emitting diodes (LEDs), etc. The biomedical applications of CQDs include bioimaging, drug delivery, gene delivery, and cancer therapy. The fluorescent CQDs have low toxicity and other exceptional physicochemical properties in comparison to heavy metals semiconductor quantum dots (QDs) which make them superior candidates for biomedical applications. In this review, the synthesis routes and optical properties of the CQDs are clarified and recent advances in CQDs biomedical applications in bioimaging (in vivo and in vitro), drug delivery, cancer therapy, their potential to pass blood-brain barrier (BBB), and gene delivery are discussed.

Image-guided cancer therapy using aptamer-functionalized cross-linked magnetic-responsive Fe3O4@carbon nanoparticles

The excellent anticancer effect of combined differential cancer therapies has been observed in the last few decades. Efficient theragnostic nanoparticles (NPs) for malignancy treatment have received considerable research attention and widely investigated today. This study presents our results on the development of aptamer-functionalized Fe₃O₄@carbon@doxorubicin NPs (Apt-Fe₃O₄@C@DOX) and their application in the synergetic chemo-photothermal therapy (PTT) of cancer. The Apt-Fe₃O₄@C@DOX NPs displayed high photothermal conversion efficiency and extensive pH/heat-induced drug release. In vitro (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium) bromide experiments indicated that the combined chemo-PTT is much more toxic toward lung adenocarcinoma cells (A549) than PTT or chemotherapy alone. In addition, the Apt-Fe₃O₄@C@DOX NPs demonstrated decreasing contrast enhancement of magnetic resonance (MR) signals, which means they may be potentially applied as a contrast agent and serve as a critical component of T₂-weighted MR imaging of tumor tissues. Taking the results together, the Apt-Fe₃O₄@C@DOX NPs show great potential for cancer therapy.

A review on nanostructured carbon quantum dots and their applications in biotechnology, sensors, and chemiluminescence

Carbon quantum dots (CQDs) are a member of carbon nanostructures family which have received increasing attention for their photoluminescence (PL), physical and chemical stability and low toxicity. The classical semiconductor quantum dots (QDs) are semiconductor particles that are able to emit fluorescence by excitation. The CQDs is mainly referred to photoluminescent carbon nanoparticles less than 10 nm, with surface modification or functionalization. Contrary to other carbon nanostructures, CQDs can be synthesized and functionalized fast and easily. The fluorescence origin of the CQDs is a controversial issue which depends on carbon source, experimental conditions, and functional groups. However, PL emissions originated from conjugated π-domains and surface defects have been proposed for the PL emission mechanisms of the CQDs. These nanostructures have been used as nontoxic alternatives to the classical heavy metals containing semiconductor QDs in some applications such as in-vivo and in-vitro bio-imaging, drug delivery, photosensors, chemiluminescence (CL), and etc. This paper will introduce CQDs, their structure, and PL characteristics. Recent advances of the application of CQDs in biotechnology, sensors, and CL is comprehensively discussed.

Novel controlled drug release system engineered with inclusion complexes based on carboxylic graphene

A novel drug carrier is constructed by compositing hydrophilic hydroxypropyl-β-cyclodextrins (HP-β-CD) and carboxylated graphene nanomaterial (GO-COOH). Fourier transform infrared spectroscopy confirms that the two materials are successfully combined via chemical bonds. Further, a crosslinking agent of glutaraldehyde is applied to fabricate composite GO-COO-HP-β-CD nanospheres, as demonstrated by an atomic force microscope. Dexamethasone (DEX) is selected as the model drug, and the drug loading efficiency and water solubility of the nanospheres greatly increased. Additionally, the achieved DEX/nanosphere inclusion complex exhibits better heat resistance compared with pure DEX, which is a desired property for drug processing. More importantly, different models are applied to different releasing durations to investigate in detail the release profile of DEX. The best fitting release kinetics model is given to reveal the release mechanism of the drug delivery system. The highest hemolysis rate of the DEX/nanosphere inclusion is 0.44%, far lower than the standard of 5% delivered by the American Society for Testing and Materials, ensuring its safety in practical applications. Meanwhile, recalcification tests indicate that DEX/nanosphere retains the normal blood coagulation function. In vitro cytotoxicity tests of the inclusion demonstrate that the nanospheres have no toxicity and are qualified for intravenous applications with good blood compatibility. Finally, the bioactivity of DEX after release from the carriers is investigated. Results corroborate that the drug anti-inflammation efficacy is not affected and that the biomedical function can be well retained. The engineered controlled drug release system represents a promising formulation platform for a broad range of therapeutic medicine in pharmaceutical technology.

Carbon-Based Nanomaterials for Cancer Therapy via Targeting Tumor Microenvironment

Cancer remains one of the major health problems all over the world and conventional therapeutic approaches have failed to attain an effective cure. Tumor microenvironments (TME) present a unique challenge in tumor therapy due to their complex structures and multiple components, which also serve as the soil for tumor growth, development, invasion, and migration. The complex TME includes immune cells, fibrous collagen structures, and tortuous blood vessels, in which conventional therapeutic approaches are rendered useless. State-of-the-art nanotechnologies have potential to cope with the threats of malignant tumors. With unique physiochemical properties, carbon nanomaterials (CNMs), including graphene, fullerenes, carbon nanotubes, and carbon quantum dots, offer opportunities to resolve the hurdles, by targeting not only cancer cells but also the TME. This review summarizes the progress about CNM-based cancer therapy strategies, which mainly focuses on both the treatment for cancer cells and TME-targeted modulation. In the last, the challenges for TME-based therapy via CNMs are discussed, which will be important in guiding current basic research to clinical translation in the future.

Progress in internal/external stimuli responsive fluorescent carbon nanoparticles for theranostic and sensing applications

In the past decade, fluorescent carbon nanoparticles (FNPs) prepared from natural resources and biomaterials have been attractive due to their various properties, such as unique optical properties, great biocompatibility, water dispersion, and facile surface functionalization. Depending on the properties of the carbon sources and the subsequent carbonization processes, internal/external stimuli responsive carbon nanoparticles have been generated that are useful for theranostic and sensing applications. In this review, we highlight the recent developments in the use of FNPs in nanomedicine in great detail, particularly for FNPs responding to internal stimuli, including redox, pH, and enzymes, and external stimuli, including temperature, light, and magnetic fields, for drug delivery and sensing applications. Furthermore, we hope to provide insight that could stimulate further research aiming for unparalleled useful applications. As a result, there are many possibilities that can be explored from this smart material.

Magnetofluorescent Carbon Quantum Dot Decorated Multiwalled Carbon Nanotubes for Dual-Modal Targeted Imaging in Chemo-Photothermal Synergistic Therapy

Magnetofluorescent nanoparticles with diagnostic and therapeutic functions show great promise in nanomedicine. Here, we report the magnetofluorescent carbon nanotubes (CNTs)/doxorubicin (DOX) nanocomposites and their functions act in synergetic chemo-photothermal synergistic therapy (Chemo/PTT) in cancer excision. Magnetofluorescent CNTs conjugated with a folic acid (FA-GdN@CQDs-MWCNTs) were targets for dual-modal fluorescence (FL)/magnetic resonance (MR) imaging. Experiments in vitro and in vivo identified FA-GdN@CQDs-MWCNTs with low toxicity, and good biocompatibility. Moreover, FA-GdN@CQDs-MWCNTs whose release can be fostered by pH and NIR light dual-stimuli had been proved to be available for loading DOX. Following nuclear translocations, FA-GdN@CQDs-MWCNTs were engineered to deliver DOX that targeted the nuclei. In vivo experiment indicates that the Chemo/PTT, as compared with the respective single treatment, can significantly control tumor growth. In addition, Chemo/PTT was not shown to render any appreciable toxicity. These findings suggest that the FA-GdN@CQDs-MWCNTs/DOX could function as a multifunctional platform for simultaneous FL/MR imaging, PTT therapy, and drug delivery.

An in vitro assessment of novel chitosan/bimetallic PtAu nanocomposites as delivery vehicles for doxorubicin

AIM

To synthesize and functionalize platinum (core)-gold (shell) bimetallic nanoparticles (PtAuBNps) with chitosan and doxorubicin to display favorable pharmacokinetics, biodegradability, biological activity and safety in vitro.

MATERIALS & METHODS

PtAuBNps and their drug nanocomposites were morphologically and physico-chemically characterized. Binding studies determined the efficiency and stability of the platform. In vitro release kinetics were evaluated under simulated environments, cytotoxicity profiles through MTT and Sulforodhamine B assays and apoptosis induction using the dual EtBr/AO staining.

RESULTS & DISCUSSION

The results obtained indicate that functionalized PtAuBNps displayed favorable physio-chemical attributes, high binding capabilities, pH-triggered drug release through zero-order release kinetics, cell-specific cytotoxicity and good colloidal stability.

CONCLUSION

The positive attributes of this novel delivery system bodes well for future in vivo studies.

N-Doped CDs–GP nanospheres as a drug delivery nanocarrier system with carbon dots and a fluorescent tracer

In this study, a carbon dots-genipin covalent conjugate (CDs–GP) was synthesized, characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and fluorescence spectroscopy (FL).

Laser-textured surface storing a carbon dots/poly(ethylene glycol)/chitosan gel with slow-release lubrication effect

Arthroplasty presents wear problems because body fluid, as the only lubricant, has poor performance.