Galactosylated chitosan-grafted multiwall carbon nanotubes for pH-dependent sustained release and hepatic tumor-targeted delivery of doxorubicin in vivo

Ligand-conjugated multiwalled carbon nanotubes for cancer targeted drug delivery

Multiwalled carbon nanotubes (MWCNTs) are at the forefront of nanotechnology-based advancements in cancer therapy, particularly in the field of targeted drug delivery. The nanotubes are characterized by their concentric graphene layers, which give them outstanding structural strength. They can deliver substantial doses of therapeutic agents, potentially reducing treatment frequency and improving patient compliance. MWCNTs' diminutive size and modifiable surface enable them to have a high drug loading capacity and penetrate biological barriers. As a result of the extensive research on these nanomaterials, they have been studied extensively as synthetic and chemically functionalized molecules, which can be combined with various ligands (such as folic acid, antibodies, peptides, mannose, galactose, polymers) and linkers, and to deliver anticancer drugs, including but not limited to paclitaxel, docetaxel, cisplatin, doxorubicin, tamoxifen, methotrexate, quercetin and others, to cancer cells. This functionalization facilitates selective targeting of cancer cells, as these ligands bind to specific receptors overexpressed in tumor cells. By sparing non-cancerous cells and delivering the therapeutic payload precisely to cancer cells, this therapeutic payload delivery ability reduces chemotherapy systemic toxicity. There is great potential for MWCNTs to be used as targeted delivery systems for drugs. In this review, we discuss techniques for functionalizing and conjugating MWCNTs to drugs using natural and biomacromolecular linkers, which can bind to the cancer cells' receptors/biomolecules. Using MWCNTs to administer cancer drugs is a transformative approach to cancer treatment that combines nanotechnology and pharmacotherapy. It is an exciting and rich field of research to explore and optimize MWCNTs for drug delivery purposes, which could result in significant benefits for cancer patients.

In silico-guided discovery and in vitro validation of novel sugar-tethered lysinated carbon nanotubes for targeted drug delivery of doxorubicin

CONTEXT

Multiwalled carbon nanotubes (MWCNTs) functionalized with lysine via 1,3-dipolar cycloaddition and conjugated to galactose or mannose are potential nanocarriers that can effectively bind to the lectin receptor in MDA-MB-231 or MCF-7 breast cancer cells. In this work, a method based on molecular dynamics (MD) simulation was used to predict the interaction of these functionalized MWCNTs with doxorubicin and obtain structural evidence that allows a better understanding of the drug loading and release process. The MD simulations showed that while doxorubicin only interacted with pristine MWCNTs through π-π stacking interactions, functionalized MWCNTs were also able to establish hydrogen bonds, suggesting that the functionalized groups improve doxorubicin loading. Moreover, the elevated adsorption levels observed for functionalized nanotubes further support this enhancement in loading efficiency. MD simulations also shed light on the intratumoral pH-specific release of doxorubicin from functionalized MWCNTs, which is induced by protonation of the daunosamine moiety. The simulations show that this change in protonation leads to a lower absorption of doxorubicin to the MWCNTs. The MD studies were then experimentally validated, where functionalized MWCNTs showed improved dispersion in aqueous medium compared to pristine MWCNTs and, in agreement with the computational predictions, increased drug loading capacity. Doxorubicin-loaded functionalized MWCNTs demonstrated specific release of doxorubicin in tumor microenvironment (pH = 5.0) with negligible release in the physiological pH (pH = 7.4). Furthermore, doxorubicin-free MWNCT nanoformulations exhibited insignificant cytotoxicity. The experimental studies yielded nearly identical results to the MD studies, underlining the usefulness of the method. Our functionalized MWCNTs represent promising non-toxic nanoplatforms with enhanced aqueous dispersibility and the potential for conjugation with ligands for targeted delivery of anti-cancer drugs to breast cancer cells.

METHODS

The computational model of a pristine carbon nanotube was created with the buildCstruct 1.2 Python script. The lysinated functionalized groups were added with PyMOL and VMD. The carbon nanotubes and doxorubicin molecules were parameterized using the general AMBER force field, and RESP charges were determined using Gaussian 09. Molecular dynamics simulations were carried out with the AMBER 20 software package. Adsorption levels were calculated using the water-shell function of cpptraj. Cytotoxicity was evaluated via a MTT assay using MDA-MB-231 and MCF-7 breast cancer cells. Drug uptake of doxorubicin and doxorubicin-loaded MWCNTs was measured by fluorescence microscopy.

ULK1 Mediated Autophagy-Promoting Effects of Rutin-Loaded Chitosan Nanoparticles Contribute to the Activation of NF-κB Signaling Besides Inhibiting EMT in Hep3B Hepatoma Cells

Background

Liver cancer remains to be one of the leading causes of cancer worldwide. The treatment options face several challenges and nanomaterials have proven to improve the bioavailability of several drug candidates and their applications in nanomedicine. Specifically, chitosan nanoparticles (CNPs) are extremely biodegradable, pose enhanced biocompatibility and are considered safe for use in medicine.

Methods

CNPs were synthesized by ionic gelation, loaded with rutin (rCNPs) and characterized by ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The rCNPs were tested for their cytotoxic effects on human hepatoma Hep3B cells, and experiments were conducted to determine the mechanism of such effects. Further, the biocompatibility of the rCNPs was tested on L929 fibroblasts, and their hemocompatibility was determined.

Results

Initially, UV-vis and FTIR analyses indicated the possible loading of rutin on rCNPs. Further, the rutin load was quantitatively measured using Ultra-Performance Liquid Chromatography (UPLC) and the concentration was 88 µg/mL for 0.22 micron filtered rCNPs. The drug loading capacity (LC%) of the rCNPs was observed to be 13.29 ± 0.68%, and encapsulation efficiency (EE%) was 19.55 ± 1.01%. The drug release was pH-responsive as 88.58% of the drug was released after 24 hrs at the lysosomal pH 5.5, whereas 91.44% of the drug was released at physiological pH 7.4 after 102 hrs. The cytotoxic effects were prominent in 0.22 micron filtered samples of 5 mg/mL rutin precursor. The particle size for the rCNPs at this concentration was 144.1 nm and the polydispersity index (PDI) was 0.244, which is deemed to be ideal for tumor targeting. A zeta potential (ζ-potential) value of 16.4 mV indicated rCNPs with good stability. The IC50 value for the cytotoxic effects of rCNPs on human hepatoma Hep3B cells was 9.7 ± 0.19 μg/mL of rutin load. In addition, the increased production of reactive oxygen species (ROS) and changes in mitochondrial membrane potential (MMP) were observed. Gene expression studies indicated that the mechanism for cytotoxic effects of rCNPs on Hep3B cells was due to the activation of Unc-51-like autophagy-activating kinase (ULK1) mediated autophagy and nuclear factor kappa B (NF-κB) signaling besides inhibiting the epithelial-mesenchymal Transition (EMT). In addition, the rCNPs were less toxic on NCTC clone 929 (L929) fibroblasts in comparison to the Hep3B cells and possessed excellent hemocompatibility (less than 2% of hemolysis).

Conclusion

The synthesized rCNPs were pH-responsive and possessed the physicochemical properties suitable for tumor targeting. The particles were effectively cytotoxic on Hep3B cells in comparison to normal cells and possessed excellent hemocompatibility. The very low hemolytic profile of rCNPs indicates that the drug could be administered intravenously for cancer therapy.

Fanarraga M. Carbon nanotubes targeted to the tumor microenvironment inhibit metastasis in a preclinical model of melanoma

Despite notable progress in cancer therapy, metastatic diseases continue to be the primary cause of cancer-related mortality. Multi-walled carbon nanotubes (MWCNTs) can enter tissues and cells and interfere with the dynamics of the cytoskeletal nanofilaments biomimetically. This endows them with intrinsic anti-tumoral effects comparable to those of microtubule-binding chemotherapies such as Taxol®. In this study, our focus was on exploring the potential of oxidized MWCNTs in selectively targeting the vascular endothelial growth factor receptor (VEGFR). Our objective was to evaluate their effectiveness in inhibiting metastatic growth by inducing anti-proliferative, anti-migratory, and cytotoxic effects on both cancer and tumor microenvironment cells. Our findings demonstrated a significant reduction of over 80 % in malignant melanoma lung metastases and a substantial enhancement in overall animal welfare following intravenous administration of the targeted biodegradable MWCNTs. Furthermore, the combination of these nanomaterials with the conventional chemotherapy agent Taxol® yielded a remarkable 90 % increase in the antimetastatic effect. These results highlight the promising potential of this combined therapeutic approach against metastatic disease and are of paramount importance as metastasis is responsible for nearly 60,000 deaths each year.

Nanocrystals Slow-Releasing Ropivacaine and Doxorubicin to Synergistically Suppress Tumor Recurrence and Relieve Postoperative Pain

Although surgical resection provides a straightforward and effective treatment for most malignant solid tumors, tumor recurrence and acute postoperative pain continue to be two big problems associated with this treatment. To resolve these problems, a nanocrystal composite slow-releasing ropivacaine and doxorubicin was fabricated in this study. Briefly, a self-assembling peptide was used to form nanoparticle complexes with the two drugs, based on which homogeneous nanocrystals were obtained by adjusting the pH. In cultured human melanoma cells, the nanocrystals exhibited improved antitumor activity due to a synergistic effect and enhanced cellular uptake of the two drugs. On the other hand, the nanocrystals could slowly release ropivacaine in vitro and in vivo, generating long-acting analgesia on the rat sciatic nerve block model and incisional pain model. On a nude mouse tumor resection model, the nanocrystals simultaneously suppressed the recurrence of solid tumor and relieved postoperative pain, indicating a potential postoperative treatment for tumor resection patients. This nanocrystal system also suggested a promising and facile strategy for developing multifunctional formulations combining different drugs, which could achieve better therapeutic outcomes in a synergistic and sustained manner.

Hepatocellular carcinoma: Preclinical and clinical applications of nanotechnology with the potential role of carbohydrate receptors

Hepatocellular carcinoma (HCC) is one of the most common types of liver cancer; accounts for 75-85% of cases. The treatment and management of HCC involve different sanative options like surgery, chemotherapy, immunotherapy, etc. Recently, various advancements have been introduced for the diagnosis and targeting of hepatic tumor cells. Among these, biomarkers are considered the primary source for the diagnosis and differentiation of tumor cells. With the advancement in the field of nanotechnology, different types of nanocarriers have been witnessed in tumor targeting. Nanocarriers such as nanoparticles, liposomes, polymeric micelles, nanofibers, etc. are readily prepared for effective tumor targeting with minimal side-effects. The emergence of various approaches tends to improve the effectiveness of these nanocarriers as demonstrated in ample clinical trials. This review focuses on the significant role of carbohydrates such as mannose, galactose, fructose, etc. in the development, diagnosis, and therapy of HCC. Hence, the current focus of this review is to acknowledge various perspectives regarding the occurrence, diagnosis, treatment, and management of HCC.

Microwave-Assisted Functionalization of Multi-Walled Carbon Nanotubes for Biosensor and Drug Delivery Applications

Microwave-assisted synthetic methods have emerged as a popular technique for surface modification and the functionalization of multi-walled carbon nanotubes (MWCNTs) for diverse drug delivery applications. Microwave-induced functionalization of MWCNTs provides a high functionalization and requires less time than conventional techniques. Microwave methods are simple, fast, and effective for the covalent and noncovalent conjugation of MWCNTs with various biomolecules and polymers. The present review focuses on the synthetic and drug delivery applications of microwave irradiation techniques (MITs) for the functionalization of MWCNTs, using amino acids and other molecular frameworks containing amino groups, vitamins, proteins, epoxy moieties, metal nanoparticles, and polymers.

Lysinated Multiwalled Carbon Nanotubes with Carbohydrate Ligands as an Effective Nanocarrier for Targeted Doxorubicin Delivery to Breast Cancer Cells

Multiwalled carbon nanotubes (MWCNTs) are elongated, hollow cylindrical nanotubes made of sp2 carbon. MWCNTs have attracted significant attention in the area of drug delivery due to their high drug-loading capacity and large surface area. Furthermore, they can be linked to bioactive ligands molecules via covalent and noncovalent bonds that allow for the targeted delivery of anticancer drugs such as doxorubicin. The majority of methodologies reported for the functionalization of MWCNTs for drug delivery are quite complex and use expensive linkers and ligands. In the present study, we report a simple, cost-effective approach for functionalizing MWCNTs with the carbohydrate ligands, galactose (GA), mannose (MA) and lactose (LA), using lysine as a linker. The doxorubicin (Dox)-loaded functionalized MWCNTs were characterized using FT-IR, NMR, Raman, XRD and FE-SEM. The drug-loaded MWCNTs were evaluated for drug loading, drug release and cell toxicity in vitro, in breast cancer cells. The results indicated that the carbohydrate-modified lysinated MWCNTs had greater Dox loading capacity, compared to carboxylated MWCNTs (COOHMWCNTs) and lysinated MWCNTs (LyMWCNTs). In vitro drug release experiments indicated that the carbohydrate functionalized LyMWCNTs had higher Dox release at pH 5.0, compared to the physiological pH of 7.4, over 120 h, indicating that they are suitable candidates for targeting the tumor microenvironment as a result of their sustained release profile of Dox. Doxorubicin-loaded galactosylated MWCNTs (Dox-GAMWCNTs) and doxorubicin loaded mannosylated MWCNTs (Dox-MAMWCNTs) had greater anticancer efficacy and cellular uptake, compared to doxorubicin-loaded lactosylated MWCNTs (Dox-LAMWCNTs) and pure Dox, in MDA-MB231 and MCF7 breast cancer cells. However, neither the ligand conjugated multiwall blank carbon nanotubes (GAMWCNTs, MAMWCNTs and LAMWCNTs) nor the lysinated multiwalled blank carbon nanotubes produced significant toxicity in the normal cells. Our results suggest that sugar-tethered multiwalled carbon nanotubes, especially the galactosylated (Dox-GAMWCNTs) and mannosylated (Dox-MAMWCNTs) formulations, may be used to improve the targeted delivery of anticancer drugs to breast cancer cells.

Anticancer therapeutic potential of phosphorylated galactosylated chitosan against N-nitrosodiethyl amine-induced hepatocarcinogenesis

Chitosan is a natural polyfunctional polymer that can be modified to achieve compounds with tailored properties for targeting and treating different cancers. In this study, we report the development and anticancer potential of phosphorylated galactosylated chitosan (PGC). The synthesized compound was characterized by FT-IR, NMR, and mass spectroscopy. The interaction of PGC with asialoglycoprotein receptors (ASGPR) and cellular internalization in HepG2 cells was studied using in silico and uptake studies respectively. PGC was evaluated for its metal chelating, ferric ion reducing, superoxide, and lipid peroxide (LPO) inhibiting potential. Further, anticancer therapeutic potential of PGC was evaluated against N-nitrosodiethylamine (NDEA)-induced hepatocellular carcinoma in a mice model. After development of cancer, PGC was administered to the treatment group (0.5 mg/kg bw, intravenously), once a week for 4 weeks. Characterization studies of PGC revealed successful phosphorylation and galactosylation of chitosan. A strong interaction of PGC with ASGP-receptors was predicted by computational studies and cellular internalization studies demonstrated 98.76 ± 0.53% uptake of PGC in the HepG2 cells. A good metal chelating, ferric ion reducing, and free radical scavenging activity was demonstrated by PGC. The anticancer therapeutic potential of PGC was evident from the observation that PGC treatment increased number of tumor free animals (50%) (6/12) and significantly (p ≤ 0.05) lowered tumor multiplicity as compared to untreated tumor group.

In vitro and in vivo evaluation of self-assembled chitosan nanoparticles selectively overcoming hepatocellular carcinoma via asialoglycoprotein receptor

Hepatocellular carcinoma (HCC) is one of the major causes of cancer-related mortality worldwide. Nowadays, liver-targeting drug delivery system has been proven as a promising strategy for overcoming HCC. Asialoglycoprotein receptor (ASGPR) is an ideal receptor for liver targeting, which is mainly expressed on hepatocytes. In this study, we developed several novel liver-targeting chitosan nanoparticles to selectively overcome HCC via ASGPR. Chitosan nanoparticles (Gly-CS-VE, Gal-Gly-CS-VE, Gly-CS-DCA, and Gal-Gly-CS-DCA) were prepared by grafting hydrophilic group (glycidol, Gly), hydrophobic group (deoxycholic acid, DCA or vitamin E succinate, VE), and ASGPR recognizing group (galactose, Gal). Subsequently, their characterizations were measured by ¹H NMR, FT-IR, TEM, and DLS. Doxorubicin (DOX) was loaded in nanoparticles and released out in a pH-dependent manner. Most importantly, the galactosylated Gal-Gly-CS-VE and Gal-Gly-CS-DCA nanoparticles exhibited significantly stronger in vitro cell internalization, cytotoxicity, anti-migration capabilities and in vivo anticancer efficacies than the corresponding Gly-CS-VE and Gly-CS-DCA nanoparticles, as well as free DOX. Finally, the four chitosan nanoparticles exhibited good biocompatibility without causing any obvious histological damage to the major organs. Overall, the galactosylated chitosan nanoparticles were proven to be promising pharmaceutical formulations for selectively overcoming HCC, with great potential for clinical applications.

Carbon nanotubes as an emerging nanocarrier for the delivery of doxorubicin for improved chemotherapy

Carbon nanotubes (CNTs), a versatile nanocarrier for doxorubicin (DOX) delivery had attracted significant attention in drug delivery of pharmaceuticals. Several properties such as high surface area, high drug loading capacity, stability, ease of functionalization, ultrahigh length to diameter ratio and good cellular uptake make them preferred nanocarrier as multipurpose drug delivery system. Several surface properties of CNTs can be easily modified by covalent/noncovalent functionalization, which can make CNTs a profound nanomaterial. Hydrophobic surface of CNTs facilitated π-π stacking interactions, with several drugs and therapeutic agents having aromatic ring in their structure, for example anthracyclines. In case some drug molecules, electrostatic interaction between drug and CNTs comes into the picture. DOX, an anthracycline anticancer drug, can easily adsorb on the surface of CNTs by π-π stacking interactions. In present article, we have reviewed various CNTs based drug delivery systems for the delivery of DOX alone or in combination with genetic materials and other drug molecules. In addition, we described recent updates in CNTs based drug delivery system for the delivery of DOX, we covered adsorption and desorption, different types of functionalization, to alter the properties of CNTs in vitro and in vivo. CNT attached many targeting ligands for the targeted delivery of DOX have also been discussed.

Recent Advances in Asialoglycoprotein Receptor and Glycyrrhetinic Acid Receptor-Mediated and/or pH-Responsive Hepatocellular Carcinoma- Targeted Drug Delivery

BACKGROUND

Hepatocellular carcinoma (HCC) seriously affects human health, especially, it easily develops multi-drug resistance (MDR) which results in treatment failure. There is an urgent need to develop highly effective and low-toxicity therapeutic agents to treat HCC and to overcome its MDR. Targeted drug delivery systems (DDS) for cancer therapy, including nanoparticles, lipids, micelles and liposomes, have been studied for decades. Recently, more attention has been paid to multifunctional DDS containing various ligands such as polymer moieties, targeting moieties, and acid-labile linkages. The polymer moieties such as poly(ethylene glycol) (PEG), chitosan (CTS), hyaluronic acid, pullulan, poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO) protect DDS from degradation. Asialoglycoprotein receptor (ASGPR) and glycyrrhetinic acid receptor (GAR) are most often used as the targeting moieties, which are overexpressed on hepatocytes. Acid-labile linkage, catering for the pH difference between tumor cells and normal tissue, has been utilized to release drugs at tumor tissue.

OBJECTIVES

This review provides a summary of the recent progress in ASGPR and GAR-mediated and/or pH-responsive HCC-targeted drug delivery.

CONCLUSION

The multifunctional DDS may prolong systemic circulation, continuously release drugs, increase the accumulation of drugs at the targeted site, enhance the anticancer effect, and reduce side effects both in vitro and in vivo. But it is rarely used to investigate MDR of HCC; therefore, it needs to be further studied before going into clinical trials.

Nanotechnology Based Approach for Hepatocellular Carcinoma Targeting

Hepatocellular carcinoma (HCC) is the primary liver cancer that has shown a high incidence and mortality rate worldwide among several types of cancers. A large variety of chemotherapeutic agents employed for the treatment have a limited success rate owing to their limited site-specific drug targeting ability. Thus, there is a demand to develop novel approaches for the treatment of HCC. With advancements in nanotechnology-based drug delivery approaches, the challenges of conventional chemotherapy have been continuously decreasing. Nanomedicines constituted of lipidic and polymeric composites provide a better platform for delivering and opening new pathways for HCC treatment. A score of nanocarriers such as surface-engineered liposomes, nanoparticles, nanotubes, micelles, quantum dots, etc., has been investigated in the treatment of HCC. These nanocarriers are considered to be highly effective clinically for delivering chemotherapeutic drugs with high site-specificity ability and therapeutic efficiency. The present review highlights the current focus on the application of nanocarrier systems using various ligand-based receptor-specific targeting strategies for the treatment and management of HCC. Moreover, the article has also included information on the current clinically approved drug therapy for hepatocellular carcinoma treatment and updates of regulatory requirements for approval of such nanomedicines.

Novel amino-β-Cyclodextrins containing polymers: Fabrication, characterization, and biological evaluation

In this study, poly (mPEGMA-co-MAA) (PA) based on monomers of mPEGMA and MAA were synthesized, and different amino-β-Cyclodextrins with various alkyl chains were conjugated to PA through carbodiimide-mediated coupling reactions. The obtained poly (mPEGMA-co-MAA-g-amino-β-CD) (PA-g-amino-β-CD) was characterized by FTIR, NMR and TGA. The fluorescence technique was used to investigate the micellization of PA-g-amino-β-CDs. The results indicated that these polymers could self-assemble into nano-micelles in water, and PA-g-HDA-β-CD possessed the lowest CMC value due to its long alkyl chains. In addition, the PA-g-HDA-β-CD micelles were in spherical shapes with the diameter of 78.5 ± 0.6 nm.The release of the model drug from PA-g-HDA-β-CD micelles was increased as the pH reduced from 7.4-5.5 at 37 °C. Cytotoxicity and cellular uptake experiments were performed in HepG2, which showed that the cargo-free PA-g-HDA-β-CD micelles did not have obvious cytotoxicity and were mainly distributed in the cytoplasm of HepG2 cells by endocytosis. Moreover, the study about in vivo distribution of the experimental rats indicated that the accumulation of PA-g-HDA-β-CD micelles mainly happened in the liver. Therefore, the novel amino-β-CD containing polymers exhibit good potential applications in drug delivery system.

Current Progress in Biomedical Applications of Chitosan-Carbon Nanotube Nanocomposites: A Review

The currently observed development of medical science results from the constant search for innovative solutions to improve the health and quality of life of patients. Particular attention is focused on the design of a new generation of materials with a high degree of biocompatibility and tolerance towards the immune system. In addition, apart from biotolerance, it is important to ensure appropriate mechanical and technological properties of materials intended for intra-body applications. Knowledge of the above parameters becomes the basis for considerations related to the possibilities of choosing the appropriate polymer materials. The researchers' interest, as evidenced by the number of available publications, is attracted by nanobiocomposites based on chitosan and carbon nanotubes, which, due to their properties, enable integration with the tissues of the human body. Nanosystems can be used in many areas of medicine. They constitute an excellent base for use as dressing materials, as they exhibit antimicrobial properties. In addition, they can be carriers of drugs and biological macromolecules and can be used in gene therapy, tissue engineering, and construction of biosensors. For this reason, potential application areas of chitosan-carbon nanotube nanocomposites in medical sciences are presented in this publication, considering the characteristics of the system components.

Nanomedicines in Diagnosis and Treatment of Cancer: An Update

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Nanomedicine has revolutionized the field of cancer detection and treatment by enabling the delivery of imaging agents and therapeutics into cancer cells. Cancer diagnostic and therapeutic agents can be either encapsulated or conjugated to nanosystems and accessed to the tumor environment through the passive targeting approach (EPR effect) of the designed nanomedicine. It may also actively target the tumor exploiting conjugation of targeting moiety (like antibody, peptides, vitamins, and hormones) to the surface of the nanoparticulate system. Different diagnostic agents (like contrast agents, radionuclide probes and fluorescent dyes) are conjugated with the multifunctional nanoparticulate system to achieve simultaneous cancer detection along with targeted therapy. Nowadays targeted drug delivery, as well as the early cancer diagnosis is a key research area where nanomedicine is playing a crucial role. This review encompasses the significant recent advancements in drug delivery as well as molecular imaging and diagnosis of cancer exploiting polymer-based, lipid-based and inorganic nanoparticulate systems.

Glycosylated-Chitosan Derivatives: A Systematic Review

Chitosan derivatives, and more specifically, glycosylated derivatives, are nowadays attracting much attention within the scientific community due to the fact that this set of engineered polysaccharides finds application in different sectors, spanning from food to the biomedical field. Overcoming chitosan (physical) limitations or grafting biological relevant molecules, to mention a few, represent two cardinal strategies to modify parent biopolymer; thereby, synthetizing high added value polysaccharides. The present review is focused on the introduction of oligosaccharide side chains on the backbone of chitosan. The synthetic aspects and the effect on physical-chemical properties of such modifications are discussed. Finally, examples of potential applications in biomaterials design and drug delivery of these novel modified chitosans are disclosed.

Nanocarrier-Based Therapeutics and Theranostics Drug Delivery Systems for Next Generation of Liver Cancer Nanodrug Modalities

The development of therapeutics and theranostic nanodrug delivery systems have posed a challenging task for the current researchers due to the requirement of having various nanocarriers and active agents for better therapy, imaging, and controlled release of drugs efficiently in one platform. The conventional liver cancer chemotherapy has many negative effects such as multiple drug resistance (MDR), high clearance rate, severe side effects, unwanted drug distribution to the specific site of liver cancer and low concentration of drug that finally reaches liver cancer cells. Therefore, it is necessary to develop novel strategies and novel nanocarriers that will carry the drug molecules specific to the affected cancerous hepatocytes in an adequate amount and duration within the therapeutic window. Therapeutics and theranostic systems have advantages over conventional chemotherapy due to the high efficacy of drug loading or drug encapsulation efficiency, high cellular uptake, high drug release, and minimum side effects. These nanocarriers possess high drug accumulation in the tumor area while minimizing toxic effects on healthy tissues. This review focuses on the current research on nanocarrier-based therapeutics and theranostic drug delivery systems excluding the negative consequences of nanotechnology in the field of drug delivery systems. However, clinical developments of theranostics nanocarriers for liver cancer are considered outside of the scope of this article. This review discusses only the recent developments of nanocarrier-based drug delivery systems for liver cancer therapy and diagnosis. The negative consequences of individual nanocarrier in the drug delivery system will also not be covered in this review.

A glance over doxorubicin based-nanotherapeutics: From proof-of-concept studies to solutions in the market

Cancer is one of the leading causes of death worldwide and, as such, efforts are being done to find new chemotherapeutic drugs or, alternatively, novel approaches for the delivery of old ones. In this scope, when used as vehicles for drugs, nanomaterials may potentially maximize the efficacy of the treatment and reduce its side effects, for example by a change in drug's pharmacokinetics, cell targeting and/or specific stimuli-responsiveness. This is the case of doxorubicin (DOX) that presents a broad spectrum of activity and is one of the most widely used chemotherapeutic drugs as first-line treatment. Indeed, DOX is a very interesting example of a drug for which several nanosized delivery systems have been developed over the years. While it is true that some of these systems are already in the market, it is also true that research on this subject remains very active and that there is a continuing search for new solutions. In this sense, this review takes the example of doxorubicin, not so much with the focus on the drug itself, but rather as a case study around which very diverse and imaginative nanotechnology approaches have emerged.

Ligand decorated chitosan as an advanced nanocarrier for targeted delivery: a critical review

Nontargeted delivery systems present nonspecific delivery, low transfection efficiency and high toxicity. Ligand-conjugated chitosan (CS) nanocarriers have emerged as an outstanding option for achieving active delivery specifically and preferentially to the target sites by exploiting receptors mediated endocytosis. Mannosylated CS nanocarriers have brought tremendous breakthrough in gene therapy and have proven to be an excellent choice for treatment of infectious and inflammatory diseases. Similarly, folate and antibodies-conjugated CS play a significant role in diagnosis and treatment of various cancers. Current evidences obviously propose ligand-decorated CS as an attractive option for diagnosis and treatment of dreadful conditions. In order to bring huge revolution in the field of targeted delivery, challenges associated with these nanocarriers needs to be addressed.

Reversible Shielding between Dual Ligands for Enhanced Tumor Accumulation of ZnPc-Loaded Micelles

Herein, we report a ligand-reversible-shielding strategy based on the mutual shielding of dual ligands tethered to the surface of nanoparticles. To exemplify this concept, phenylboronic acid-functionalized poly(ethylene glycol)- b-poly(ε-caprolactone) (PBA-PEG-PCL) and galactose-functionalized diblock polymer (Gal-PEG-PCL) were mixed to form dual-ligand micelles (PBA/Gal). PBA and Gal residues could form a complex at pH 7.4 and mutually shield their targeting function. At pH 6.8, the binding affinity between PBA and Gal weakened, and PBA preferred to bind with the sialic acid residues on the tumor cell surface rather than to Gal on the micellar surface; furthermore, the unbound Gal recovered its targeting ability toward the asialoglycoprotein receptor. When the pH decreased from 7.4 to 6.8, enzyme-linked immunosorbent assays exhibited that the percentage of exposed Gal on the micellar surface increased 1.9-fold, and flow cytometry showed that HepG2 cellular uptake increased 4.3-fold. More importantly, this process was reversible, confirming the reversible shielding and deshielding of dual ligands. With the encapsulation of a photosensitizer, zinc phthalocyanine (ZnPc), the reversible-shielding micelles showed a 48% improvement in the half-life ( t_1/2) in blood circulation, a 54% decrease in liver capture, a 40% increase in tumor accumulation, and a 10.3% improvement in the tumor inhibition rate compared to the Gal-coated irreversible micelles. This dual-ligand mutual-shielding strategy provides a new perspective on reversible tumor targeting.

Functionalized carbon nanotubes as emerging delivery system for the treatment of cancer

In recent time, carbon nanotubes (CNTs) have gained vital importance for pharmaceutical formulation scientist for delivering drugs and genes, owing to their excellent surface properties. For example, their aspect ratio is thought to be responsible for their excellent cell penetration aptitude; anisotropic conductivity/semi-conductivity along their axis is ideal for integration with nervous and muscular tissue; an ultrahigh surface area maximizes their ability to "talk" with biological matter; the hollow interior provides an enormous cargo-carrying capacity for drug delivery; and their exteriors are readily functionalized to permit tailoring of solubility and biological recognition. Despite their immense capabilities for the delivery of drugs, genes and other biomedically essential materials, there use is restricted primarily because of the severe toxicity. However, the reactive nature of the surface of the CNTs allowed attaching the guest molecules (drug, siRNA, and diagnostics) of interest which helps in increasing the biocompatibility of these novel nanocarriers. As per the need, CNTs can be modified with peptides, organic molecules, carbohydrates, polymers and used mainly for cancer targeting and tumor cell accumulation. This review expounds different functionalization strategies employed for CNTs that created new opportunities for scientists to improve the potential of delivered therapeutics.

Carbon nanomaterials in oncology: an expanding horizon

Carbon nanomaterials have been attracting attention in oncology for the development of safe and effective cancer nanomedicines in increasing improved patient compliance for generally recognized as safe (GRAS) prominence. Toxicity, safety and efficacy of carbon nanomaterials are the major concerns in cancer theranostics. Various parameters such as particle size and shape or surface morphology, surface charge, composition, oxidation and nonoxidative-stress-related mechanisms are prone to toxicity of the carbon nanomaterials. Currently, few cancer-related products have been available on the market, although some are underway in preclinical and clinical phases. Thus, our main aim is to provide comprehensive details on the carbon nanomaterials in oncology from the past two decades for patient compliance and safety.

Poly(malic acid) bearing Doxorubicin and N-Acetyl Galactosamine as a site-specific prodrug for targeting hepatocellular carcinoma

In the past, several systems of drug delivery carriers have been designed with a high capacity to target specific cells and/or tissues and a reduced non-specific toxicity. In this context, we synthesized and characterized novel poly(malic acid) derivatives bearing Doxorubicin (Dox), Poly(ethylene glycol) (PEG) and/or N-Acetyl Galactosamine (NAcGal) for drug delivery. These poly(malic acid) derivatives were obtained by chemical modification of the carboxylic acid lateral groups of poly(malic acid) (PMLA). The resulting nanoplatforms were evaluated for their in vitro cytotoxicity using the human HepaRG hepatoma cell line. Results reveal that the PMLA nanoplatform modified with PEG and Dox has an IC₅₀ of 936 nM corresponding to a Dox concentration of 47 nM, while the grafting of NAcGal onto the nanoplatform reduced the IC₅₀ to 527 nM corresponding to a Dox concentration of 26 nM. The presence of the targeting moiety, NAcGal, thus improves the cellular toxicity of the Dox.

Simultaneous monitoring of the drug release and antitumor effect of a novel drug delivery system-MWCNTs/DOX/TC

Monitoring drug release and therapeutic efficacy is crucial for developing drug delivery systems. Our preliminary study demonstrated that, as compared with pristine multiwalled carbon nanotubes (MWCNTs), transactivator of transcription (TAT)-chitosan functionalized MWCNTs (MWCNTs-TC) were a more promising candidate for drug delivery in cancer therapy. In the present study, a MWCNTs/TC-based drug delivery system was developed for an anticancer drug, doxorubicin (DOX). The drug loading and in vitro release profiles, cellular uptake and cytotoxicity were assessed. More importantly, the in vivo drug release and antitumor effect of MWCNTs/DOX/TC were evaluated by noninvasive fluorescence and bioluminescence imaging. It was demonstrated that MWCNTs/DOX/TC can be efficiently taken up by BEL-7402 hepatoma cells. The release of DOX from MWCNTs/DOX/TC was faster under lower pH condition, which was beneficial for intrcellular drug release. The in vivo release process of DOX and antitumor effect in animal model were monitored simultaneously by noninvasive fluorescence and luminescence imaging, which demonstrated the application potential of MWCNTs/DOX/TC for cancer therapy.

Recent advances in carbon based nanosystems for cancer theranostics

This review deals with four different types of carbon allotrope based nanosystems and summarizes the results of recent studies that are likely to have applications in cancer theranostics. We discuss the applications of these nanosystems for cancer imaging, drug delivery, hyperthermia, and PDT/TA/PA.

pH-controlled doxorubicin anticancer loading and release from carbon nanotube noncovalently modified by chitosan: MD simulations

In the present study, we describe here the pH condition activating doxorubicin (DOX) anticancer drugs loading and release over single-wall carbon nanotube (SWNT) non-covalently wrapped with chitosan (CS). The possibility of drug displacement on DOX/CS/SWNT nanocarrier was investigated using molecular dynamics simulations. The drug loading and release were monitored via displacement analysis and binding energy calculations. The simulated results clearly showed that the drugs well interacted with the CS/SWNT at physiological pH (pH 7.4), where CS was in the deprotonated form. Contrastingly, in weakly acidic environments (pH 5.0-6.5) which is a pH characteristics of certain cancer environments, the protonated CS became loosen wrapped around the SWNT and triggered drugs release as a result of charge-charge repulsion between CS and drug molecules. The obtained data fulfil the understanding at atomic level of drug loading and release controlled by pH-sensitive polymer, which might be useful for further cancer therapy researches.

A Eu(3+)/Gd(3+)-EDTA-doped structurally controllable hollow mesoporous carbon for improving the oral bioavailability of insoluble drugs and in vivo tracing

A structurally controllable fluorescence-labeled hollow mesoporous carbon (HMC) was simply prepared to improve the oral bioavailability of insoluble drugs and further trace their delivery process in vivo. The hollow structure was derived from an inverse replica process using mesoporous silica as a template and the fluorescent label was prepared by doping the carboxylated HMC with a confinement of Eu(3+)/Gd(3+)-EDTA. The physicochemical properties of the composites were systematically characterized by transmission electron microscopy, Fourier transform infrared spectroscopy and photoluminescence spectra tests prior to studying their effects on drug-release behavior and biodistribution. As a result, the thickness of the carrier's shell was adjusted from 70 nm to 130 nm and the maximum drug loading was up to 73.6%. The model drug carvedilol (CAR) showed sustained release behavior compared to CAR commercial capsules, and the dissolution rate slowed down as the shells got thicker. AUC0-48h and Tmax were enlarged 2.2 and 6.5 fold, respectively, which demonstrated that oral bioavailability was successfully improved. Bioimaging tests showed that the novel carbon vehicle had a long residence time in the gastrointestinal tract. In short, the newly designed HMC is a promising drug carrier for both oral bioavailability improvement and in vivo tracing.

Experimental Study of Magnetic Multi-Walled Carbon Nanotube-Doxorubicin Conjugate in a Lymph Node Metastatic Model of Breast Cancer

BACKGROUND The lymphatic system plays a significant role in the defense of a subject against breast cancer and is one of the major pathways for the metastasis of breast cancer. To improve the prognosis, many means, including surgery, radiotherapy, and chemotherapy, have been used. However, the combination of all these modalities has limited efficacy. Lymph nodes, therefore, have become an exceptionally potential target organ in cancer chemotherapy. MATERIAL AND METHODS A lymph node metastatic model of breast cancer was established in BALB/c mice. Magnetic multi-walled carbon nanotube carrier with good adsorption and lymph node-targeting capacity was prepared and conjugated with doxorubicin to make the magnetic multi-walled carbon nanotube-doxorubicin suspension. Dispersions of doxorubicin, magnetic multi-walled carbon nanotube-doxorubicin, and magnetic multi-walled carbon nanotube were injected into lymph node metastatic mice to compare their inhibitory effects on tumor cells in vivo. Inhibition of these dispersions on EMT-6 breast cancer cells was detected via MTT assay in vitro. RESULTS Although no significant difference was found between the effects of doxorubicin and magnetic multi-walled carbon nanotube-doxorubicin with the same concentration of doxorubicin on EMT-6 breast cancer cells in vitro, in terms of sizes of metastatic lymph nodes and xenograft tumors, apoptosis in metastatic lymph nodes, and adverse reactions, the magnetic multi-walled carbon nanotube-doxorubicin group differed significantly from the other groups. CONCLUSIONS The magnetic multi-walled carbon nanotube-doxorubicin clearly played an inhibitory role in lymph node metastases to EMT-6 breast cancer cells.

Recent advances in cellulose and chitosan based membranes for water purification: A concise review

Recently membrane technology has emerged as a new promising and pervasive technology due to its innate advantages over traditional technologies such as adsorption, distillation and extraction. In this article, some of the recent advances in developing polymeric composite membrane materials for water purification from natural polysaccharide based polymers namely cellulose derivatives and chitosan are concisely reviewed. The impact of human social, demographic and industrial evolution along with expansion through environment has significantly affected the quality of water by pollution with large quantities of pesticides, minerals, drugs or other residues. At the forefront of decontamination and purification techniques, we found the membrane materials from polymers as a potential alternative. In an attempt to reduce the number of technical polymers widely used in the preparation of membranes, many researchers have reported new solutions for desalination or retention of organic yeasts, based on bio renewable polymers like cellulose derivatives and chitosan. These realizations are presented and discussed in terms of the most important parameters of membrane separation especially water flux and retention in this article.