Graphene-Based Photodynamic Therapy and Overcoming Cancer Resistance Mechanisms: A Comprehensive Review

Photodynamic therapy (PDT) is a non-invasive therapy that has made significant progress in treating different diseases, including cancer, by utilizing new nanotechnology products such as graphene and its derivatives. Graphene-based materials have large surface area and photothermal effects thereby making them suitable candidates for PDT or photo-active drug carriers. The remarkable photophysical properties of graphene derivates facilitate the efficient generation of reactive oxygen species (ROS) upon light irradiation, which destroys cancer cells. Surface functionalization of graphene and its materials can also enhance their biocompatibility and anticancer activity. The paper delves into the distinct roles played by graphene-based materials in PDT such as photosensitizers (PS) and drug carriers while at the same time considers how these materials could be used to circumvent cancer resistance. This will provide readers with an extensive discussion of various pathways contributing to PDT inefficiency. Consequently, this comprehensive review underscores the vital roles that graphene and its derivatives may play in emerging PDT strategies for cancer treatment and other medical purposes. With a better comprehension of the current state of research and the existing challenges, the integration of graphene-based materials in PDT holds great promise for developing targeted, effective, and personalized cancer treatments.

Self-Luminescent Drug Delivery Vehicle: Synthesis, Self-Assembly Behavior, Cysteine-Responsive Property, and Application in the Visualization of Drug Release

Targeted drug delivery systems have gained great attention from the chemistry and biomedical fields in recent years due to the minimized harm to normal cells. When designing targeted drug delivery systems, the property of harmlessness to normal cells and the tracking ability of the whole process are quite crucial. These two characters can be brought into the related systems by applying a drug carrier that is self-luminescent and its drug release can be induced by the microenvironment of cancer cells. Therefore, the design and synthesis of drug delivery vehicles are significant for the fabrication of target drug delivery systems. Herein, we have synthesized a cysteine-responsive and fluorescent molecule, maleic acid-modified tetraphenylethylene derivative (MATPE), by a facile method. In addition, a drug delivery system with self-luminescence and cysteine-responsiveness based on the self-assembly of MATPE was fabricated. In this system, MATPE and cysteine both played dual roles as cysteine probe/drug carrier and emission-enhanced inducement/drug-release stimulus. The drug-release process was successfully realized in cancer cells and can be visualized, exhibiting great potential in the field of theranostics.

Enantioselective Labeling of Zebrafish for D-Phenylalanine Based on Graphene-Based Nanoplatform

Enantioselective labeling of important bioactive molecules in complex biological environments by artificial receptors has drawn great interest. From both the slight difference of enantiomers' physicochemical properties and inherently complexity in living organism point of view, it is still a contemporary challenge for preparing practical chiral device that could be employed in the model animal due to diverse biological interference. Herein, we introduce γ-cyclodextrin onto graphene oxide for fabricating γ-cyclodextrin and graphene oxide assemblies, which provided an efficient nanoplatform for chiral labelling of D-phenylalanine with higher chiral discrimination ratio of KD/KL = 8.21. Significantly, the chiral fluorescence quenching effect of this γ-CD-GO nanoplatform for D-phenylalanine enantiomer in zebrafish was 7.0-fold higher than L-isomer, which exhibiting real promise for producing practical enantio-differentiating graphene-based systems in a complex biological sample.

3D self-assembled nanocarriers for drug delivery

There are many benefits to drug delivery from drug-carrier nanostructure systems. It might be developed to carefully control drug release rates or to deliver a precise amount of a therapeutic substance to particular body areas. Self-assembling is the process by which molecules and nanoparticles spontaneously organize into organized clusters. For instance, proteins and peptides can interact with one another to create highly organized supramolecular structures with various properties, such as helical ribbons and fibrous scaffolds. Another advantage of self-assembly is that it may be effective with a variety of materials, including metals, oxides, inorganic salts, polymers, semiconductors, and even organic semiconductors. Fullerene, graphene, and carbon nanotubes (CNTs), three of the most fundamental classes of three-dimensionally self-assembling nanostructured carbon-based materials, are essential for the development of modern nanotechnologies. Self-assembled nanomaterials are used in a variety of fields, including nanotechnology, imaging, and biosensors. This review study begins with a summary of various major 3D nanomaterials, including graphene oxide, CNTs, and nanodiamond, as well as 3D self-assembled polyfunctionalized nanostructures and adaptable nanocarriers for drug delivery.

ROS- and pH-Responsive Polydopamine Functionalized Ti3C2Tx MXene-Based Nanoparticles as Drug Delivery Nanocarriers with High Antibacterial Activity

Premature drug release and poor controllability is a challenge in the practical application of tumor therapy, which may lead to poor chemotherapy efficacy and severe adverse effects. In this study, a reactive oxygen species (ROS)-cleavable nanoparticle system (MXene-TK-DOX@PDA) was designed for effective chemotherapy drug delivery and antibacterial applications. Doxorubicin (DOX) was conjugated to the surface of (3-aminopropyl)triethoxysilane (APTES)-functionalized MXene via an ROS-cleavable diacetoxyl thioketal (TK) linkage. Subsequently, the surfaces of the MXene nanosheets were coated with pH-responsive polydopamine (PDA) as a gatekeeper. PDA endowed the MXene-TK-DOX@PDA nanoparticles with superior biocompatibility and stability. The MXene-TK-DOX@PDA nanoparticles had an ultrathin planar structure and a small lateral size of approximately 180 nm. The as-synthesized nanoparticles demonstrated outstanding photothermal conversion efficiency, superior photothermal stability, and a remarkable extinction coefficient (23.3 L g^-1 cm^-1 at 808 nm). DOX exhibited both efficient ROS-responsive and pH-responsive release performance from MXene-TK-DOX@PDA nanoparticles due to the cleavage of the thioketal linker. In addition, MXene-TK-DOX@PDA nanoparticles displayed high antibacterial activity against both Gram-negative Escherichia coli (E. coli) and Gram-positive Bacillus subtilis (B. subtilis) within 5 h. Taken together, we hope that MXene-TK-DOX@PDA nanoparticles will enrich the drug delivery system and significantly expand their applications in the biomedical field.

Drug Release Kinetics of DOX-Loaded Graphene-Based Nanocarriers for Ovarian and Breast Cancer Therapeutics

Cancer remains one of the leading causes of death worldwide despite extensive efforts at developing curative treatments. Chemotherapy, one of the most common forms of treatment, lacks specificity and can induce collateral damages to healthy surrounding tissues/cells and elicit off-target toxic side effects. The carbon-based nanomaterial graphene, can load aromatic drugs with high efficiency, has good biocompatibility, and can be easily functionalised with targeting ligands, antibodies, and biomolecules to increase the accuracy of targeting specific areas; graphene has therefore been explored as a nanocarrier for classical chemotherapy drugs. In this work, seventeen publications that report the release of doxorubicin (DOX) from 2D graphene-based nanohybrids (graphene oxide and reduced graphene oxide) for the treatment of breast and ovarian cancers have been identified based on a range of inclusion and exclusion criteria. To aid in the clinical translation of proof-of-concept studies, this work identifies the pre-clinical experimental protocols and analyses the release kinetics of these publications. Fifteen of the papers utilised a change in pH as the stimulus for drug release, and two utilised either near infrared (NIR) or ultrasound as the stimulus. The extracted drug release data from these publications were fit to four known kinetic models. It was found that the majority of these data best fit the Weibull kinetic model. The agreement between the kinetic data in previously published literature provides a predictable estimation of DOX release from graphene-based nanocarriers. This study demonstrates the potential conjugation of graphene and DOX in drug delivery applications, and this knowledge can help improve to the design and formulation of future graphene-based nanocarriers. In addition, the use of further experimental testing and the standardisation of experimental protocols will be beneficial for future work. The incorporation of computational modelling prior to pre-clinical testing will also aid in the development of controlled and sustained DOX release systems that offer efficient and efficacious results.

Graphene-laden hydrogels: A strategy for thermally triggered drug delivery

The synthesis of graphene-based materials has attracted considerable attention in drug delivery strategies. Indeed, the conductivity and mechanical stability of graphene have been investigated for controlled and tunable drug release via electric or mechanical stimuli. However, the design of a thermo-sensitive scaffold using pristine graphene (without distortions related to the oxidation processes) has not been deeply investigated yet, although it may represent a promising approach for several therapeutic treatments. Here, few-layer graphene was used as a nanofiller in a hydrogel system with a thermally tunable drug release profile. In particular, varying the temperature (25 °C, 37 °C and 44 °C), responsive drug releases were noticed and hypothesized depending on the formation and perturbation of π-π interactions involving graphene, the polymeric matrix and the model drug (diclofenac). As a result, these hybrid hydrogels show a potential application as thermally triggered drug release systems in several healthcare scenarios.

A Comprehensive Insight Towards Pharmaceutical Aspects of Graphene Nanosheets

Graphene Derivatives (GDs) have captured the interest and imagination of pharmaceutical scientists. This review exclusively provides pharmacokinetics and pharmacodynamics information with a particular focus on biopharmaceuticals. GDs can be used as multipurpose pharmaceutical delivery systems due to their ultra-high surface area, flexibility, and fast mobility of charge carriers. Improved effects, targeted delivery to tissues, controlled release profiles, visualization of biodistribution and clearance, and overcoming drug resistance are examples of the benefits of GDs. This review focuses on the application of GDs for the delivery of biopharmaceuticals. Also, the pharmacokinetic properties and the advantage of using GDs in pharmaceutics will be reviewed to achieve a comprehensive understanding about the GDs in pharmaceutical sciences.

Potentiated cytosolic drug delivery and photonic hyperthermia by 2D free-standing silicene nanosheets for tumor nanomedicine

Silicene, as an emerging two-dimensional (2D) silicon allotrope, mainly serves in the field of electronics and energy devices but multidisciplinary studies on 2D silicene have been rarely carried out, especially the potential translational biomedical practice. In this study, we explore a high-performance photonic drug-delivery nanoplatform based on 2D ultrathin silicene nanosheets (DOX@silicene-BSA NSs) regarding effective chemotherapeutic drug loading (capacity amount of w/w%: 137.0%) while highlighting the potentiated cytosolic drug-delivery efficiency (spatiotemporally pH-/NIR-triggered drug-release) and NIR-II-activated photonic hyperthermia (η = 19.7%) performance, thus, enabling the potential synergistic chemotherapeutic and phototherapeutic outcomes. The cellular endocytotic mechanism of these nanosheets in cancer cells has been comprehensively studied and provides an essential understanding of the nano-bio interactions of silicene-based nanosheets or other emerging 2D nanostructures. Prominent suppression of tumor growth was achieved by synergistic chemotherapy and photonic hyperthermia with negligible adverse effects and expected degradability, thus addressing the several fundamental barriers of oncology-related nanotherapies. This work highlights silicene, which integrates the merits of high specific surface area endowed with 2D topology, intrinsic responsiveness toward physical/chemical stimuli, and biomedical necessity of biodegradation and biosafety, as a promising next-generation omnipotent alternative to subrogate traditional silicon-based biomaterials and non-biocompatible nanoagents in clinical translation nanomedicine.

Principles of Magnetic Hyperthermia: A Focus on Using Multifunctional Hybrid Magnetic Nanoparticles

Hyperthermia is a noninvasive method that uses heat for cancer therapy where high temperatures have a damaging effect on tumor cells. However, large amounts of heat need to be delivered, which could have negative effects on healthy tissues. Thus, to minimize the negative side effects on healthy cells, a large amount of heat must be delivered only to the tumor cells. Magnetic hyperthermia (MH) uses magnetic nanoparticles particles (MNPs) that are exposed to alternating magnetic field (AMF) to generate heat in local regions (tissues or cells). This cancer therapy method has several advantages, such as (a) it is noninvasive, thus requiring surgery, and (b) it is local, and thus does not damage health cells. However, there are several issues that need to achieved: (a) the MNPs should be biocompatible, biodegradable, with good colloidal stability (b) the MNPs should be successfully delivered to the tumor cells, (c) the MNPs should be used with small amounts and thus MNPs with large heat generation capabilities are required, (d) the AMF used to heat the MNPs should meet safety conditions with limited frequency and amplitude ranges, (e) the changes of temperature should be traced at the cellular level with accurate and noninvasive techniques, (f) factors affecting heat transport from the MNPs to the cells must be understood, and (g) the effect of temperature on the biological mechanisms of cells should be clearly understood. Thus, in this multidisciplinary field, research is needed to investigate these issues. In this report, we shed some light on the principles of heat generation by MNPs in AMF, the limitations and challenges of MH, and the applications of MH using multifunctional hybrid MNPs.

Effect of pH-Responsive Charge-Conversional Polymer Coating to Cationic Reduced Graphene Oxide Nanostructures for Tumor Microenvironment-Targeted Drug Delivery Systems

Tumor tissue represents a slightly acidic pH condition compared to normal tissue due to the accumulation of lactic acids via anaerobic metabolism. In this work, pH-responsive charge-conversional polymer (poly(ethylene imine)-poly(l-lysine)-poly(l-glutamic acid), PKE polymer) was employed for endowing charge-conversional property and serum stability to poly(ethylene imine) conjugated reduced graphene oxide-based drug delivery system (PEI-rGO). Zeta-potential value of PEI-rGO coated with PK5E7 polymer (PK5E7(PEI-rGO)) was -10.9 mV at pH 7.4 and converted to 29.2 mV at pH 6.0, showing pH-responsive charge-conversional property. Sharp-edged plate morphology of PEI-rGO was transformed to spherical nanostructures with vague edges by PK5E7 coating. Size of PK5E7(PEI-rGO) was found to be smaller than that of PEI-rGO in the serum condition, showing its increased serum stability. Loaded doxorubicin (DOX) in PK5E7(PEI-rGO) could be released rapidly in lysosomal condition (pH 5.0, 5 mM glutathione). Furthermore, DOX-loaded PK5E7(PEI-rGO) showed enhanced anticancer activity in HeLa and A549 cells in the tumor microenvironment-mimicking condition (pH 6.0, serum), which would be mediated by non-specific cellular interaction with decorated serum proteins. These results indicate that the pH-responsive charge-conversional PKE polymer coating strategy of cationic rGO nanostructures possesses a potential for acidic tumor microenvironment-targeted drug delivery systems.

Graphene Oxide Nanoparticles Having Long Wavelength Absorbing Chlorins for Highly-Enhanced Photodynamic Therapy with Reduced Dark Toxicity

The long wavelength absorbing photosensitizer (PS) is important in allowing deeper penetration of near-infrared light into tumor tissue for photodynamic therapy (PDT). A suitable drug delivery vehicle is important to attain a sufficient concentration of PS at the tumor site. Presently, we developed graphene oxide (GO) nanoparticles containing long wavelength absorbing PS in the form of the chlorin derivative purpurin-18-N-ethylamine (maximum absorption wavelength [λmax] 707 nm). The GO-PS complexes comprised a delivery system in which PS was loaded by covalent and noncovalent bonding on the GO nanosheet. The two GO-PS complexes were fully characterized and compared concerning their synthesis, stability, cell viability, and dark toxicity. The GO-PS complexes produced significantly-enhanced PDT activity based on excellent drug delivery effect of GO compared with PS alone. In addition, the noncovalent GO-PS complex displayed higher photoactivity, corresponding with the pH-induced release of noncovalently-bound PS from the GO complex in the acidic environment of the cells. Furthermore, the noncovalently bound GO‒PS complex had no dark toxicity, as their highly organized structure prevented GO toxicity. We describe an excellent GO complex-based delivery system with significantly enhanced PDT with long wavelength absorbing PS, as well as reduced dark toxicity as a promising cancer treatment.

Synthesis of Graphene Oxide-Fe3O4 Based Nanocomposites Using the Mechanochemical Method and in Vitro Magnetic Hyperthermia

The study presented in this work consists of two parts: The first part is the synthesis of Graphene oxide-Fe3O4 nanocomposites by a mechanochemical method which, is a mechanical process that is likely to yield extremely heterogeneous particles. The second part includes a study on the efficacy of these Graphene oxide-Fe3O4 nanocomposites to kill cancerous cells. Iron powder, ball milled along with graphene oxide in a toluene medium, underwent a controlled oxidation process. Different phases of GO-Fe3O4 nanocomposites were obtained based on the composition used for milling. As synthesized nanocomposites were characterized by x-ray diffraction (XRD), alternating magnetic field (AFM), Raman spectroscopy, and a vibrating sample magnetometer (VSM). Additionally, the magnetic properties required to obtain high SAR values (Specific Absorption Rate-Power absorbed per unit mass of the magnetic nanocomposite in the presence of an applied magnetic field) for the composite were optimized by varying the milling time. Nanocomposites milled for different extents of time have shown differential behavior for magneto thermic heating. The magnetic composites synthesized by the ball milled method were able to retain the functional groups of graphene oxide. The efficacy of the magnetic nanocomposites for killing of cancerous cells is studied in vitro using HeLa cells in the presence of an AC (Alternating Current) magnetic field. The morphology of the HeLa cells subjected to 10 min of AC magnetic field changed considerably, indicating the death of the cells.

Delivery of Oridonin and Methotrexate via PEGylated Graphene Oxide

Graphene oxide (GO) possessing plenty of hydroxyls and carboxyls is often used in the field of biomedicine. To improve its water solubility and biocompatibility, 6-armed poly(ethylene glycol) (PEG) was bonded on the surface of GO sheets via a facile amidation process to form the universal drug delivery platform (GO-PEG_10K-6arm) with a 200 nm size in favor of the enhanced permeability and retention effect. Herein, we prepared the stable and biocompatible platform of GO-PEG_10K-6arm under mild conditions and characterized the chemical structure and micromorphology via thermogravimetric analysis and atomic force microscopy. This nanosized GO-PEG_10K-6arm was found to be of very low toxicity to human normal cells of 293T and tumor cells of CAL27, MG63, and HepG2. Moreover, oridonin and methotrexate (MTX), widely used hydrophobic cancer chemotherapy drugs, were compounded with GO-PEG_10K-6arm via π-π stacking and hydrophobic interactions so as to afford nanocomplexes of oridonin@GO-PEG_10K-6arm and MTX@GO-PEG_10K-6arm, respectively. Both nanocomplexes could quickly enter into tumor cells, which was evidenced by inverted fluorescence microscopy using fluorescein isothiocyanate as a probe, and they both showed remarkably high cytotoxicity to the tumor cells of CAL27, MG63, and HepG2 within a broad range of concentration in comparison with free drugs. This kind of nanoscale drug delivery system based on GO-PEG_10K-6arm may have potential applications in biomedicine, and GO-PEG_10K-6arm would be a universal and available carrier for extensive hydrophobic anticarcinogens.

Self-Assembled 2D Glycoclusters for the Targeted Delivery of Theranostic Agents to Triple-Negative Breast Cancer Cells

Triple-negative breast cancer (TNBC) is a devastating disease worldwide, for which targeted imaging and therapeutic agents remain elusive. There has been growing awareness that carbohydrates are valuable as drug candidates and targeting agents for a variety of human diseases, including cancers that overexpress carbohydrate receptors on the cell surface. Here, we develop a two-dimensional (2D) glycocluster by means of simple, stepwise self-assembly for the targeted delivery of theranostic agents to TNBC cells that express mannose receptors (MRs) on the cell surface. Human serum albumin, which contains a variety of hydrophobic pockets capable of accommodating small molecules, was used to simultaneously encapsulate a mannose-based glycoprobe and a commercial photosensitizer (i.e., Ce6). The multicomponent "neoglycoprotein" formed was used to self-assemble with 2D MnO₂, producing 2D glycoclusters, which could be selectively internalized by a TNBC cell line (MDA-MB-231) as facilitated by binding to the transmembrane MR. The intracellular degradation of the 2D MnO₂ backbone by biothiols then released Ce6 for cell imaging and, subsequently, photodynamic therapy. This study provides insights into the development of carbohydrate-based materials for targeted, stimuli-responsive theranostics of TNBC.

Cobalt nanowire-based multifunctional platform for targeted chemo-photothermal synergistic cancer therapy

Cobalt nanowires (CoNWs) simultaneously possessing advantages in photothermal effect, targeting drug delivery and photoacoustic imaging property are hopefully promising strategies to further improve the treatment efficiency and reduce the side effects of cancer chemotherapy. Herein, a unique cobalt-based structure decorated with graphene oxide (GO) and polyethylene glycol (PEG) is fabricated through a facile approach. The resultant nanohybrids show relatively low cytotoxicity, favorable biocompatibility as well as inherit the outstanding properties of cobalt. Moreover, CoNWs decorated with GO and PEG (CoNWs-GO-PEG) can load therapeutic drug molecules (e.g., doxorubicin, DOX) with a high drug loading capacity (992.91 mg/g), and simultaneously they are responsive to pH, NIR (near-infrared) irradiation and magnetism stimulation. Accordingly, CoNWs-GO-PEG-DOX shows the satisfactory effect of eliminating cancer cells with synergistic chemo-photothermal therapy in vitro. Current work provides a solid demonstration of the potential of CoNWs-GO-PEG for serving as a targeted antitumor agent in synergistic chemo-photothermal therapy.

Applications of graphene oxide in case of nanomedicines and nanocarriers for biomolecules: review study

In this Review article, recent progress in matter of graphene oxide (GO) synthesis and its functionalization via a vast range of materials, including small molecules, polymers, and biomolecules, were reported and systematically summarized in order to overcome the inherent drawbacks of GO nanocarriers and thereby make these nanocarriers suitable for delivering chemotherapeutic agents, genes, and short interfering RNAs. Briefly, this work describes current strategies for the large scale production of GO and modification of graphene-based nanocarriers surfaces through practical chemical approaches, improving their biocompatibility and declining their toxicity. It also describes the most relevant cases of study suitable to demonstrate the role of graphene and graphene derivatives (GD) as nanocarrier for anti-cancer drugs and genes (e.g. miRNAs). Moreover, the controlled release mechanisms within the cell compartments and blood pH for targeted therapeutics release in the acidic environment of tumor cells or in intracellular compartments are mentioned and explored.

Graphene-based advanced nanoplatforms and biocomposites from environmentally friendly and biomimetic approaches

Environmentally friendly and biomimetic approaches to fabricate graphene-based advanced nanoplatforms and biocomposites for biomedical applications are summarized in this review.

Reduced graphene oxide (rGO) hybridized hydrogel as a near-infrared (NIR)/pH dual-responsive platform for combined chemo-photothermal therapy

For personalized cancer treatment, developing smart biomaterials with multiple biological functions is indispensable in nanomedicine fields. In this work, we developed a highly efficient near-infrared- (NIR-) and pH-responsive carboxymethyl chitosan-functionalized reduced graphene oxide/aldehyde functionalized poly (ethylene glycol) (CMC-rGO/CHO-PEG) hydrogel, which exhibits outstanding delivery performance of antitumor drug, doxorubicin hydrochloride (DOX). CMC was functionalized on the GO nanosheets via a controllable approach in order to achieve strong NIR absorption property and good distribution of rGO. The intercalation effect of CMC-rGO complex improved rGO distribution in the 3D hydrogel, contributing to the enhanced photothermal performance of CMC-rGO/CHO-PEG hydrogel. Furthermore, potential utilization of these CMC-rGO/CHO-PEG hydrogel for drug loading was studied, which provided pH-sensitive release of DOX payload. Particularly, DOX could be released in a more efficient way under acidic environment (pH = 6.5) than that under physiological environment (pH = 7.4). Therefore, this rGO hybridized PEG hydrogel holds strategic potential as a novel drug release platform for combined chem-photothermal therapy.

Application of polydopamine in tumor targeted drug delivery system and its drug release behavior

Inspired by the bionics of marine mussels, polydopamine (PDA), a new polymer with unique physicochemical properties was discovered. Due to its simple preparation, good biocompatibility, unique drug-loading methods, PDA has attracted tremendous attentions in field of drug delivery and imaging, and the combination of chemotherapy and other therapies or diagnostic methods, such as photothermotherapy (PTT), photoacoustic imaging (PAI), magnetic resonance imaging (MRI), etc. As an excellent drug carrier in tumor targeted drug delivery system, the drug release behavior of drug-loaded PDA-based nanoparticles is also an important factor to be considered in the establishment of drug delivery systems. Therefore, the purpose of this review is to provide a comprehensive overview of the various applications of PDA in tumor targeted drug delivery systems and to gain insight into the release behavior of the drug-loaded PDA-based nanocarriers. A sufficient understanding and discussion of these aspects is expected to provide a better way to design more rational and effective PDA-based tumor nano-targeted delivery systems. Apart from this, the prospects for the future application of PDA in this field and some unique insights are listed at the end of the article.

Monitoring of topoisomerase (I) inhibitor camptothecin release from endogenous redox-stimulated GO-polymer hybrid carrier

We have developed endogenous redox-responsive polymer conjugated GO-based hybrid nanomaterials (GO-PEGssFol-CPT) for delivery of anticancer drug camptothecin (CPT) to the cancer cells. The synthesized intermediate (PEG_SSFol) and CPT loaded GO- PEG_SSFol were characterized using Fourier transform infrared spectroscopy (FTIR) and ¹H NMR. The morphological feature changes of TEM and AFM images have confirmed the loading of CPT on the nanocarrier and its release from the nanocarrier. The amount of CPT was loaded was found to be 14.2%. The extent of camptothecin (CPT) release from GO-BiotinPVA-CPT in the presence of different concentrations of glutathione (GSH) was monitored with the increase in the fluorescence intensity at λ_max 438 nm and UV-Vis absorbance at 366 nm. The time-dependent camptothecin (CPT) release was monitored in the presence of GSH. It was noticed that CPT was completely released from GO-PEGssFol-CPT within 45 min. This release process is free from interference by other ubiquitous analytes in the living system. The constant fluorescence intensity of GO-PEGssFol-CPT against acidic pH indicated that CPT would not be released in the extracellular region of cancer cells. Therefore, such delivery system could be used to prevent unwanted cytotoxicity to the healthy cells. The GO-PEGssFol-CPT showed higher antiproliferative activity against cervical cancer cells compared to the CPT. Thus, GO-PEGssFol-CPT can be a new material to deliver the anticancer drug to the target tumor region.

A Review on Graphene-Based Nanomaterials in Biomedical Applications and Risks in Environment and Health

Graphene-based nanomaterials (GBNs) have attracted increasing interests of the scientific community due to their unique physicochemical properties and their applications in biotechnology, biomedicine, bioengineering, disease diagnosis and therapy. Although a large amount of researches have been conducted on these novel nanomaterials, limited comprehensive reviews are published on their biomedical applications and potential environmental and human health effects. The present research aimed at addressing this knowledge gap by examining and discussing: (1) the history, synthesis, structural properties and recent developments of GBNs for biomedical applications; (2) GBNs uses as therapeutics, drug/gene delivery and antibacterial materials; (3) GBNs applications in tissue engineering and in research as biosensors and bioimaging materials; and (4) GBNs potential environmental effects and human health risks. It also discussed the perspectives and challenges associated with the biomedical applications of GBNs.

Thermosensitive Lipid Bilayer-Coated Mesoporous Carbon Nanoparticles for Synergistic Thermochemotherapy of Tumor

Thermochemotherapy exhibits a synergistic therapeutic efficiency for cancer, and the sensitivity of cancer cells to chemical drugs could be increased to a large extent at elevated temperature. In this work, a biocompatible nanocomposite thermosensitive mesoporous carbon nanoparticles (TSMCN) was prepared by covering a liposome on mesoporous carbon nanoparticles (MCN). The TSMCN had good photothermal efficiency and photostability. The doxorubicin (DOX)-loaded TSMCN (DOX/TSMCN) showed a slower release than the DOX-loaded MCN-COOH (DOX/MCN-COOH) both in simulated tumor environment and physiological environment. And release curves of DOX/TSMCN exposed to NIR laser exhibited the fast release property. The confocal laser scanning microscopy results illustrated that cellular uptake of DOX for DOX/TSMCN can be enhanced by NIR laser. The temperature of the tumor site reached up to 51.9 °C within 3 min after exposure to laser at 1.25 W/cm² power density, which is above the phase transition temperature ( T_m) of liposome (40.7 °C). The biodistribution of DOX in vivo indicated that NIR laser can prolong the retardation time of DOX in the tumor site. The results of both 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and antitumor efficiency elucidated that the DOX/TSMCN under NIR irradiation had a synergistic therapeutic effect for cancer. Thus, the TSMCN could be explored as a powerful nanoplatform that shows great prospect in thermochemotherapy of tumor therapy.

PEGylated graphene oxide-mediated quercetin-modified collagen hybrid scaffold for enhancement of MSCs differentiation potential and diabetic wound healing

Nanoscale delivery based on polyethylene glycol (PEG)ylated graphene oxide (GO-PEG) merits attention for biomedical applications owing to its functional surface modification, superior solubility/biocompatibility and controllable drug release capability. However, impaired skin regeneration in applications of these fascinating nanomaterials in diabetes is still limited, and critical issues need to be addressed regarding insufficient collagen hyperplasia and inadequate blood supply. Therefore, a high-performance tissue engineering scaffold with biocompatible and biodegradable properties is essential for diabetic wound healing. Natural and artificial acellular dermal matrix (ADM) scaffolds with spatially organized collagen fibers can provide a suitable architecture and environment for cell attachment and proliferation. Here, a novel collagen-nanomaterial-drug hybrid scaffold was constructed from GO-PEG-mediated quercetin (GO-PEG/Que)-modified ADM (ADM-GO-PEG/Que). The resulting unique and versatile hybrid scaffold exhibited multiple advantages, including the following: a biocompatible, cell-adhesive surface for accelerating mesenchymal stem cell (MSC) attachment and proliferation; superior stability and adjustability of the conduction potential of quercetin for inducing the differentiation of MSCs into adipocytes and osteoblasts; and a biodegradable nanofiber interface for promoting collagen deposition and angiogenesis in diabetic wound repair. This study provides new prospects for the design of innovative GO-PEG-based collagen hybrid scaffolds for application in efficient therapeutic drug delivery, stem cell-based therapies, tissue engineering and regenerative medicine.

pH-Sensitive graphene oxide conjugate purpurin-18 methyl ester photosensitizer nanocomplex in photodynamic therapy

A GO–Pu18 composite showed excellent photodynamic bioactivity and pH-sensitive drug release behavior.

Mesoporous polydopamine nanoparticles with co-delivery function for overcoming multidrug resistance via synergistic chemo-photothermal therapy

Theranostic agents for combined chemo-photothermal therapy have attracted intensive interest in the treatment of multi-drug resistance (MDR) in cancer therapy. However, the development of simple theranostic agents as dual hosts for both heat and a high payload of chemotherapeutic agents remains a big challenge. Herein, mesoporous polydopamine nanoparticles (MPDA) were successfully developed with properties of a high payload of DOX (up to 2000 μg mg^-1) and the drug efflux inhibitor TPGS (d-α-tocopheryl polyethylene glycol 1000 succinate), as well as strong near-infrared absorption. Particularly, DOX and TPGS were sequentially loaded in the pore space and on the external particle surface of MPDA via π-π stacking and hydrophobic interactions, resulting in a MPDA-DOX@TPGS complex. The DOX release observably relies on the pH value and glutathione (GSH). Furthermore, it is possible to accelerate the rate of drug release by NIR irradiation. Importantly, the MPDA-DOX@TPGS complex was found to escape from endosomes after cellular uptake and release the loaded drugs into the cytosol. By TPGS mediated MDR reversal, the delivered DOX induced significant cytotoxicity to MCF-7/ADR cells. Besides, MPDA can absorb the NIR light and convert it into fatal heat to kill the cancer cells. As a consequence, the combined therapy in our system yields a synergistic effect with high therapeutic efficacy.

Black Phosphorus Nanosheet-Based Drug Delivery System for Synergistic Photodynamic/Photothermal/Chemotherapy of Cancer

A black phosphorus (BP)-based drug delivery system for synergistic photodynamic/photothermal/chemotherapy of cancer is constructed. As a 2D nanosheet, BP shows super high drug loading capacity and pH-/photoresponsive drug release. The intrinsic photothermal and photodynamic effects of BP enhance the antitumor activities. The synergistic photodynamic/photothermal/chemotherapy makes BP-based drug delivery system a multifunctional nanomedicine platform.

Advanced Functional Nanomaterials for Theranostics

Nanoscale materials have been explored extensively as agents for therapeutic and diagnostic (i.e. theranostic) applications. Research efforts have shifted from exploring new materials in vitro to designing materials that function in more relevant animal disease models, thereby increasing potential for clinical translation. Current interests include non-invasive imaging of diseases, biomarkers and targeted delivery of therapeutic drugs. Here, we discuss some general design considerations of advanced theranostic materials and challenges of their use, from both diagnostic and therapeutic perspectives. Common classes of nanoscale biomaterials, including magnetic nanoparticles, quantum dots, upconversion nanoparticles, mesoporous silica nanoparticles, carbon-based nanoparticles and organic dye-based nanoparticles, have demonstrated potential for both diagnosis and therapy. Variations such as size control and surface modifications can modulate biocompatibility and interactions with target tissues. The needs for improved disease detection and enhanced chemotherapeutic treatments, together with realistic considerations for clinically translatable nanomaterials will be key driving factors for theranostic agent research in the near future.

Facile synthesis of a highly water-soluble graphene conjugated chlorophyll-a photosensitizer composite for improved photodynamic therapy in vitro

Graphene conjugated withp-bromo-phenylhydrazone-methyl pyropheophorbide-a (BPMppa, 683 nm), which is derived from a chlorophyll-aphotosensitizer, shows significantly improved water-solubility and PDT efficiency.

Glucose-Reduced Graphene Oxide with Excellent Biocompatibility and Photothermal Efficiency as well as Drug Loading

In the present work, we report a facile and rapid green strategy to fabricate functionalized reduced nano-graphene oxide (nrGO) as a cooperative nanotemplate for both photothermal therapy and drug loading. Graphite oxide was firstly oxidated by nitronium ions (NO2 (+)) solution at the aid of microwave heating to obtain nano-GO (nGO) with about 50 nm of diameter, and the nGO was then reduced in pure glucose at 135 °C for 30 min to obtain nrGO with about 40 nm of diameter. The nrGO exhibits excellent biocompatibility including stable dispersibility in cell culture medium and rapid cellular uptake as well as non-cytotoxicity up to 100 μg/mL. Absorption of the nrGO at 808 nm wavelength increased more than 10-folds compared with nGO. Moreover, the nrGO has the ability to load about 317 % (w/w) of doxorubicin (DOX), and the loaded DOX could be effectively released by acid condition and/or glutathione (GSH) and/or heating. Finally, a greater cancer cell death efficacy was observed in nrGO/DOX-treated cells with GSH and heating stimulation respectively or their combination. Collectively, the nrGO developed here is an outstanding cooperative nano-platform for high-efficiency photothermal therapy and controllable drug delivery.

Graphene-based nanosheets for delivery of chemotherapeutics and biological drugs

Graphene-based nanosheets (GNS), including graphenes, graphene oxides and reduced graphene oxides, have properties suitable for delivery of various molecules. With their two-dimensional structures, GNS provide relatively high surface areas and capacity for non-covalent π-π stacking and hydrophobic interactions with various drug molecules. Currently, GNS-based delivery applications extend to chemotherapeutics as well as biological drugs, including nucleic acid drugs, proteins, and peptides. Surfaces of GNS have been modified with various polymers, such as polyethylene glycol and biopolymers, which enhance biocompatibility and increase drug loading. Anticancer drugs are prominent among chemotherapeutic agents tested, and have been loaded onto GNS with relatively high loading capacities compared with other nanocarriers. For enhanced distribution to specific tissues, GNS have been covalently or non-covalently modified with targeting ligands, including folic acid, transferrins, and others. In this review, we cover the current status of GNS for delivery of anticancer chemotherapeutics and biological drugs, with a focus on nucleic acid drugs. Remaining challenges for the application of GNS for drug-delivery systems and future perspectives are also addressed.

Aminoglycoside-derived amphiphilic nanoparticles for molecular delivery

The development of effective drug carriers can lead to improved outcomes in a variety of disease conditions. Aminoglycosides have been used as antibacterial therapeutics, and are attractive as monomers for the development of polymeric materials in various applications. Here, we describe the development of novel aminoglycoside-derived amphiphilic nanoparticles for drug delivery, with an eye towards ablation of cancer cells. The aminoglycoside paromomycin was first cross-linked with resorcinol diglycidyl ether leading to the formation of a poly (amino ether), PAE. PAE molecules were further derivatized with methoxy-terminated poly(ethylene glycol) or mPEG resulting in the formation of mPEG-PAE polymer, which self-assembled to form nanoparticles. Formation of the mPEG-PAE amphiphile was characterized using (1)H NMR, (13)C NMR, gel permeation chromatography (GPC) and FTIR spectroscopy. Self-assembly of the polymer into nanoparticles was characterized using dynamic light scattering, zeta potential analyses, atomic force microscopy (AFM) and the pyrene fluorescence assay. mPEG-PAE nanoparticles were able to carry significant amounts of doxorubicin (DOX), presumably by means of hydrophobic interactions between the drug and the core. Cell-based studies indicated that mPEG-PAE nanoparticles, loaded with doxorubicin, were able to induce significant loss in viabilities of PC3 human prostate cancer, MDA-MB-231 human breast cancer, and MB49 murine bladder cancer cells; empty nanoparticles resulted in negligible losses of cell viability under the conditions investigated. Taken together, our results indicate that the mPEG-PAE nanoparticle platform is attractive for drug delivery in different applications, including cancer.

GSH-responsive biotinylated poly(vinyl alcohol)-grafted GO as a nanocarrier for targeted delivery of camptothecin

A water-soluble and biocompatible polymer, i.e. biotinylated poly(vinyl alcohol)-grafted graphene oxide (GO), was used as a nanocarrier for targeted delivery of anticancer drug camptothecin (CPT).

Semiconductor and carbon-based fluorescent nanodots: the need for consistency

The need for establishing the bases and definitions of photoluminescent nanodots is discussed and their state-of-the-art in analytical and biomedical research fields is highlighted.

Fabrication of magnetite nanoparticle doped reduced graphene oxide grafted polyhydroxyalkanoate nanocomposites for tissue engineering application

In tissue engineering, the magnetic nanocomposites are more attractive due to some superior properties that promote in the monitoring of cell proliferation, differentiation and activation of cell construction in tissue regeneration phase.

Near-infrared light-responsive nanomaterials for cancer theranostics

Early diagnosis and effective cancer therapy are required, to properly treat cancer, which causes more than 8.2 million deaths in a year worldwide. Among various cancer treatments, nanoparticle-based cancer therapies and molecular imaging techniques have been widely exploited over the past decades to overcome current drawbacks of existing cancer treatments. In particular, gold nanoparticles (AuNPs), carbon nanotubes (CNTs), graphene oxide (GO), and upconversion nanocrystals (UNCs) have attracted tremendous attention from researchers due to their near-infrared (NIR) light-responsive behaviors. These nanomaterials are considered new multifunctional platforms for cancer theranostics. They would enable on-demand control of drug release or molecular imaging in response to a remote trigger by NIR light exposure. This approach allows the patient or physician to adjust therapy precisely to a target site, thus greatly improving the efficacy of cancer treatments, while reducing undesirable side effects. In this review, we have summarized the advantages of NIR light-responsive nanomaterials for in vivo cancer treatments, which includes NIR triggered photothermal therapy (PTT) and photodynamic therapy (PDT). Furthermore, recent developments, perspectives, and new challenges of NIR light-responsive nanomaterials are discussed for cancer theranostic applications.