Doxorubicin loaded carboxymethyl cellulose/graphene quantum dot nanocomposite hydrogel films as a potential anticancer drug delivery system

Mechanistic Insights into the Release of Doxorubicin from Graphene Oxide in Cancer Cells

Liposomal doxorubicin (L-DOX) is a popular drug formulation for the treatment of several cancer types (e.g., recurrent ovarian cancer, metastatic breast cancer, multiple myeloma, etc.), but poor nuclear internalization has hampered its clinical applicability so far. Therefore, novel drug-delivery nanosystems are actively researched in cancer chemotherapy. Here we demonstrate that DOX-loaded graphene oxide (GO), GO-DOX, exhibits much higher anticancer efficacy as compared to its L-DOX counterpart if administered to cellular models of breast cancer. Then, by a combination of live-cell confocal imaging and fluorescence lifetime imaging microscopy (FLIM), we suggest that GO-DOX may realize its superior performances by inducing massive intracellular DOX release (and its subsequent nuclear accumulation) upon binding to the cell plasma membrane. Reported results lay the foundation for future exploitation of these new adducts as high-performance nanochemotherapeutic agents.

Mimicking the Endometrial Cancer Tumor Microenvironment to Reprogram Tumor-Associated Macrophages in Disintegrable Supramolecular Gelatin Hydrogel

Purpose

Besides the tumor cells themselves, solid tumors are comprised of numerous cell types including infiltrating immune cells such as tumor-associated macrophages (TAMs). TAMs are vital stromal components of host immune system and play a critical role in the development of cancer. TAMs can be divided into two subtypes: M1 tumor-suppressive macrophage and M2 tumor-supportive macrophage. To better address the observations of TAMs functional performance, we describe an in vitro system that mimics the populations of TAMs infiltrated into the tumor mass by using our disintegrable supramolecular gelatin (DSG) hydrogels, which are physically crosslinked by host-guest complexations.

Materials and Methods

The host–guest interaction was adopted between the aromatic groups of gelatin and the photocrosslinkable acrylated β-cyclodextrins (Ac-β-CDs) to form the DSG hydrogels. The convenient macrophage/endometrial cancer cells heterospheroid 3D model was set up by DSG hydrogels. RT-PCR and Western blot assays were developed to evaluate the efficiencies of inducers on the macrophages. The ELISA and oxygen saturation assays were performed to measure the secretion of VEGF and consumption of oxygen of tumor and/or macrophages, respectively. To determine the antitumor effects of M2 reprogrammed macrophages in vitro and in vivo, migration assay and tumor xenograft model were used, respectively.

Results

The host-guest complexations of DSG hydrogels were controllably broken efficiently by soaking into the solution of competitive guest monomers 1-adamantanamine hydrochloride. The DSG hydrogels help IFN-γ reprogram the M2 to M1 and then decrease the tumor/M2 reprogrammed macrophage cells heterospheroid secretion of VEGF and increase the relative oxygen saturation. Significantly, the co-cultural tumor/M2 reprogrammed group from the disintegrated DSG hydrogels reduced the migration of cancer cells in vitro and the tumor growth in vivo.

Conclusion

We obtain a TAMs/tumor microenvironment-responsive 3D model based on the novel DSG hydrogels, and will be of utility in cancer therapy and drug discovery.

Graphene oxide as a potential drug carrier - Chemical carrier activation, drug attachment and its enzymatic controlled release

Graphene oxide (GO), due to its properties, such as nanometric dimensions, large specific surface area, and biocompatibility, can be used as a carrier in controlled drug release systems. The method of its chemical activation before drug molecules binding was elaborated. Doxorubicin (DOX), an anticancer drug, was attached to the surface of GO via the Gly-Gly-Leu linker. Approximately 3.07 · 10²⁰ molecules of the tripeptide were attached to 1 g of GO and subsequently almost the same number of DOX molecules. GO was suspended inside a sol surrounded by a thin porous membrane. The bound DOX was effectively released using thermolysin, an enzyme cleaving peptide bonds between Gly and Leu inside the linker structure. The membrane, as the shell was responsible for keeping enzyme molecules in their native form and GO flakes inside the carrier, simultaneously allowed the released drug molecules to diffuse outside. The rate of drug release was described as a function of the enzyme concentration and mass of DOX expressed on carrier volume; thus, the daily dose and length of the therapy can be controlled. Studies involving the cell line of mice fibrosarcoma WEHI 164 have shown that the prepared carrier itself is not toxic and only the introduction of DOX-releasing enzyme into it causes cell death.

Facile preparation of pH-sensitive chitosan microspheres for delivery of curcumin; characterization, drug release kinetics and evaluation of anticancer activity

Curcumin (CUR) is a lowly water-soluble natural polyphenol with chemopreventive and chemotherapeutic activities. Hence, to achieve the system with good CUR loading ability, porous MIL-88 (Fe) was prepared in the presence of the presynthesized graphene quantum dots (GQDs) (GQDs@MIL-88 (Fe)). In the following, CUR loaded in the fabricated GQDs@MIL-88 (Fe) nanohybrid. The characterization techniques; Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), scanning electron microscope (SEM), photoluminescence (PL), and Brunauer-Emmett-Teller (BET) analysis showed success in the synthesis of GQDs@MIL-88 (Fe). Moreover, the FT-IR analysis displayed the loading of CUR and the formation of CUR@GQDs@MIL-88(Fe). Chitosan (CS) was used as a green coating to enhance the biocompatibility of the prepared system (CS/CUR@GQDs@MIL-88(Fe). The fabricated microspheres showed pH-sensitive swelling behavior and released 38.3% of CUR in pH 5.0 which is better fitted with the First-order kinetic model (R² = 0.9726). In comparison with CUR@GQDs@MIL-88(Fe), the MTT and DAPI assay exhibited less toxic effect for CS/CUR@GQDs@MIL-88(Fe) against MDA-MB 231 cells. Moreover, the safety of the CS/CUR@GQDs@MIL-88(Fe) confirmed after incubation against MCF 10A as a model of the normal cell line. The results conveyed a new concept that the CS/CUR@GQDs@MIL-88(Fe) is a potential candidate for using as a biocompatible carrier with controlled drug delivery ability.

Synthesis of photoluminescent glycodendrimer with terminal β-cyclodextrin molecules as a biocompatible pH-sensitive carrier for doxorubicin delivery

In the present research, we prepared new glycodendrimer containing β-cyclodextrin (β-CD) in three steps. At first, graphene quantum dots (GQDs) synthesized through pyrolysis of the citric acid (CA). Then the polyamidoamine (PAMAM) dendrimer was grown from the surface of the modified GQDs (GQDs-PAMAM). Finally, the prepared GQDs-PAMAM was functionalized with β-CD to obtain the glycodendrimer (GQDs-PAMAM-β-CD). The synthesized glycodendrimer characterized using several techniques. The phenol-sulfuric acid test obtained the amount of the β-CD about 30.37 %. 61.2 % of doxorubicin (DOX) was loaded in the prepared glycodendrimer. DOX@GQDs-PAMAM-β-CD displayed the pH-sensitive drug release profile, which fitted the Higuchi kinetic model. The biological test outcomes showed that the GQDs-PAMAM-β-CD is a safe carrier with good capability in penetration to the cancer cells. Moreover, DOX@GQDs-PAMAM-β-CD exhibited more efficiency in the killing of the cancer cells compared to neat DOX. Obtained results suggested that prepared glycodendrimer could be a potential nanosystem for breast cancer treatment.

Carbon Dots Conjugated with Vascular Endothelial Growth Factor for Protein Tracking in Angiogenic Therapy

One of the challenges of using growth factors for tissue regeneration is to monitor their biodistributions and delivery to injured tissues for minimally invasive detection. In the present study, tracking of human vascular endothelial growth factor (VEGF) was achieved by chemically linking it to photoluminescent carbon dots (CDs). Carbon dots were synthesized by the hydrothermal method and, subsequently, conjugated with VEGF using carbodiimide coupling. ELISA and western blot analysis revealed that VEGF-conjugated CDs preserve the binding affinity of VEGF to its antibodies. We also show that VEGF-conjugated CDs maintain the functionality of VEGF for tube formation and cell migration. The VEGF-conjugated CDs were also used for in vitro imaging of human umbilical vein endothelial cells. The results of this work suggest that cell-penetrating VEGF-conjugated CDs can be used for growth factor protein tracking in therapeutic and tissue engineering applications.

Improvement of conventional anti-cancer drugs as new tools against multidrug resistant tumors

Multidrug resistance (MDR) is the dominant cause of the failure of cancer chemotherapy. The design of antitumor drugs that are able to evade MDR is rapidly evolving, showing that this area of biomedical research attracts great interest in the scientific community. The current review explores promising recent approaches that have been developed with the aim of circumventing or overcoming MDR. Encouraging results have been obtained in the investigation of the MDR-modulating properties of various classes of natural compounds and their analogues. Inhibition of P-gp or downregulation of its expression have proven to be the main mechanisms by which MDR can be surmounted. The use of hybrid molecules that are able to simultaneously interact with two or more cancer cell targets is currently being explored as a means to circumvent drug resistance. This strategy is based on the design of hybrid compounds that are obtained either by merging the structural features of separate drugs, or by conjugating two drugs or pharmacophores via cleavable/non-cleavable linkers. The approach is highly promising due to the pharmacokinetic and pharmacodynamic advantages that can be achieved over the independent administration of the two individual components. However, it should be stressed that the task of obtaining successful multivalent drugs is a very challenging one. The conjugation of anticancer agents with nitric oxide (NO) donors has recently been developed, creating a particular class of hybrid that can combat tumor drug resistance. Appropriate NO donors have been shown to reverse drug resistance via nitration of ABC transporters and by interfering with a number of metabolic enzymes and signaling pathways. In fact, hybrid compounds that are produced by covalently attaching NO-donors and antitumor drugs have been shown to elicit a synergistic cytotoxic effect in a variety of drug resistant cancer cell lines. Another strategy to circumvent MDR is based on nanocarrier-mediated transport and the controlled release of chemotherapeutic drugs and P-gp inhibitors. Their pharmacokinetics are governed by the nanoparticle or polymer carrier and make use of the enhanced permeation and retention (EPR) effect, which can increase selective delivery to cancer cells. These systems are usually internalized by cancer cells via endocytosis and accumulate in endosomes and lysosomes, thus preventing rapid efflux. Other modalities to combat MDR are described in this review, including the pharmaco-modulation of acridine, which is a well-known scaffold in the development of bioactive compounds, the use of natural compounds as means to reverse MDR, and the conjugation of anticancer drugs with carriers that target specific tumor-cell components. Finally, the outstanding potential of in silico structure-based methods as a means to evaluate the ability of antitumor drugs to interact with drug transporters is also highlighted in this review. Structure-based design methods, which utilize 3D structural data of proteins and their complexes with ligands, are the most effective of the in silico methods available, as they provide a prediction regarding the interaction between transport proteins and their substrates and inhibitors. The recently resolved X-ray structure of human P-gp can help predict the interaction sites of designed compounds, providing insight into their binding mode and directing possible rational modifications to prevent them from becoming P-gp drug substrates. In summary, although major efforts were invested in the search for new tools to combat drug resistant tumors, they all require further implementation and methodological development. Further investigation and progress in the abovementioned strategies will provide significant advances in the rational combat against cancer MDR.

Applications of Nanocellulose/Nanocarbon Composites: Focus on Biotechnology and Medicine

Nanocellulose/nanocarbon composites are newly emerging smart hybrid materials containing cellulose nanoparticles, such as nanofibrils and nanocrystals, and carbon nanoparticles, such as "classical" carbon allotropes (fullerenes, graphene, nanotubes and nanodiamonds), or other carbon nanostructures (carbon nanofibers, carbon quantum dots, activated carbon and carbon black). The nanocellulose component acts as a dispersing agent and homogeneously distributes the carbon nanoparticles in an aqueous environment. Nanocellulose/nanocarbon composites can be prepared with many advantageous properties, such as high mechanical strength, flexibility, stretchability, tunable thermal and electrical conductivity, tunable optical transparency, photodynamic and photothermal activity, nanoporous character and high adsorption capacity. They are therefore promising for a wide range of industrial applications, such as energy generation, storage and conversion, water purification, food packaging, construction of fire retardants and shape memory devices. They also hold great promise for biomedical applications, such as radical scavenging, photodynamic and photothermal therapy of tumors and microbial infections, drug delivery, biosensorics, isolation of various biomolecules, electrical stimulation of damaged tissues (e.g., cardiac, neural), neural and bone tissue engineering, engineering of blood vessels and advanced wound dressing, e.g., with antimicrobial and antitumor activity. However, the potential cytotoxicity and immunogenicity of the composites and their components must also be taken into account.

pH/Reduction dual-responsive comet-shaped PEGylated CQD-DOX conjugate prodrug: Synthesis and self-assembly as tumor nanotheranostics

Carbon quantum dots (CQDs) show promising potential for tumor imaging owing to their unique superior fluorescent properties. However, the small particle size limits their practical application. Here, pH/reduction dual-responsive comet-shaped PEGylated CQD-DOX conjugate prodrug, DOX-Hy-CQD-SS-PEG with DOX content of 28.5%, was designed with the hydrophobic acid-labile DOX conjugated CQDs as comet nucleus and the few hydrophilic bioreducible detachable PEG brushes as comet tails. The comet-shaped DOX-Hy-CQD-SS-PEG prodrug could self-assemble into unique micelles with mean diameter of 127 nm. The DOX-Hy-CQD-SS-PEG micelles possessed excellent pH/reduction dual-responsive drug release with low drug leakage of 9% in 150 h. Furthermore, the fluorescent CQDs was recovered after DOX release and de-PEGylation, demonstrating their potential application for real-time response of therapy.

Rare-earth metal–organic frameworks: from structure to applications

In the past 30 years, rare-earth metal–organic frameworks (MOFs) have been gaining attention owing to their diverse chemical structures, and tunable properties.

Montmorillonite-based polyacrylamide hydrogel rings for controlled vaginal drug delivery

Vaginal drug delivery is regarded as a promising route against women-related health issues such as unwanted pregnancies and sexually transmitted infections. However, only a very few studies have been reported on the use of hydrogel rings with low cytotoxicity for vaginal drug delivery applications. Moreover, the effect of nanoparticles on hydrogel vaginal rings has not been clearly evaluated. To overcome these challenges, we hereby developed nanocomposite hydrogel rings based on polyacrylamide-sodium carboxymethyl cellulose-montmorillonite nanoparticles in the ring-shaped aluminum mold for controlled drug delivery. The hydrogel rings were synthesized by using N,N'-methylene bisacrylamide, N,N,N',N'-tetramethyl ethylene diamine, and ammonium persulfate, as a crosslinker, accelerator, and initiator, respectively. The obtained rings were 5.5 cm in diameters and 0.5 cm in rims. Chemical structures of the nanocomposite rings were confirmed by Fourier transform infrared, and Nuclear Magnetic Resonance spectroscopies. Additionally, the swelling ratio of hydrogels was appeared to be adjusted by the introduction of nanoparticles. In vitro release experiment of methylene blue, as a hydrophilic model drug, revealed that the nanocomposite rings could not only reduce burst effect (almost more than twice), but also achieve prolonged release for 15 days in the vaginal fluid simulant which mimic the vaginal conditions at pH of almost 4.2, and a temperature of 37 °C. Importantly, the resultant hydrogel rings with or without various concentrations of montmorillonite showed low cytotoxicity toward human skin fibroblasts. Furthermore, different antibacterial activities against Escherichia coli were observed for various concentrations of montmorillonite in hydrogels. These results suggest the great potential of montmorillonite-based hydrogel rings for vaginal drug delivery.

Graphenic Materials for Biomedical Applications

Graphene-based nanomaterials have been intensively studied for their properties, modifications, and application potential. Biomedical applications are one of the main directions of research in this field. This review summarizes the research results which were obtained in the last two years (2017-2019), especially those related to drug/gene/protein delivery systems and materials with antimicrobial properties. Due to the large number of studies in the area of carbon nanomaterials, attention here is focused only on 2D structures, i.e. graphene, graphene oxide, and reduced graphene oxide.

Capecitabine-loaded anti-cancer nanocomposite hydrogel drug delivery systems: in vitro and in vivo efficacy against the 4T1 murine breast cancer cells

In this work, nanocomposite hydrogel drug delivery systems based on polyvinyl alcohol and montmorillonite loaded with the capecitabine, as an anti-cancer drug, were developed for oral administration. The gel fraction and swelling ability of the prepared nanocomposite hydrogels were experimentally measured. In vitro release kinetics of capecitabine in nanocomposite hydrogel drug delivery systems were studied. In vitro flow cytometry assay was utilized to exhibit the anti-cancer activity of the prepared nanocomposite hydrogel drug delivery systems against 4T1 cancer cell line. The anti-tumor efficacy of the nanocomposite hydrogel drug delivery systems was also studied in vivo on animal models. The results showed that the amount of montmorillonite incorporated into the nanocomposite hydrogel drug delivery systems could be recognized as a key parameter to adjust the values of the gel fraction, swelling and capecitabine release rate in a manner which by increasing the montmorillonite content, the gel fraction is increased while the swelling and drug release rate are decreased. The flow cytometry results demonstrated the better anti-cancer activity of the capecitabine-loaded nanocomposite hydrogel drug delivery systems as compared with the pure capecitabine. The in vivo assays indicated that the administration of nanocomposite hydrogel drug delivery systems had a significant effect on the reduction of the tumor growth in animal models as compared with pure capecitabine administration. In general, the prepared nanocomposite hydrogel drug delivery systems exhibited a suitable efficacy against 4T1 cancer cell line both in vitro and in vivo and they could be considered as promising candidates for controlled release of anti-cancer drugs in chemotherapy with enhanced therapeutic effects.

Investigation of Metal-Organic Framework-5 (MOF-5) as an Antitumor Drug Oridonin Sustained Release Carrier

Oridonin (ORI) is a natural active ingredient with strong anticancer activity. But its clinical use is restricted due to its poor water solubility, short half-life, and low bioavailability. The aim of this study is to utilize the metal organic framework material MOF-5 to load ORI in order to improve its release characteristics and bioavailability. Herein, MOF-5 was synthesized by the solvothermal method and direct addition method, and characterized by Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), Thermogravimetric Analysis (TG), Brunauer-Emmett-Teller (BET), and Dynamic Light Scattering (DLS), respectively. MOF-5 prepared by the optimal synthesis method was selected for drug-loading and in vitro release experiments. HepG2 cells were model cells. MTT assay, 4',6-diamidino-2-phenylindole (DAPI) staining and Annexin V/PI assay were used to detect the biological safety of blank carriers and the anticancer activity of drug-loaded materials. The results showed that nano-MOF-5 prepared by the direct addition method had complete structure, uniform size and good biocompatibility, and was suitable as an ORI carrier. The drug loading of ORI@MOF-5 was 52.86% ± 0.59%. The sustained release effect was reliable, and the cumulative release rate was about 87% in 60 h. ORI@MOF-5 had significant cytotoxicity (IC50:22.99 μg/mL) and apoptosis effect on HepG2 cells. ORI@MOF-5 is hopeful to become a new anticancer sustained release preparation. MOF-5 has significant potential as a drug carrier material.

Graphene-based hybrid nanoparticle of doxorubicin for cancer chemotherapy

Background

Prostate cancer (PC) has the highest prevalence in men and accounts for a high rate of neoplasia-related death. Doxorubicin (DOX) is one of the most widely used anti-neoplastic drugs for prostate cancer among others. However, it has low specificity and many side effects and affects normal cells. More recently, there have been newly developed drug delivery tools which are graphene or graphene-based, used to increase the specificity of the delivered drug molecules. The graphene derivatives possess both π-π stacking and increased hydrophobicity, factors that increase the likelihood of drug delivery. Despite this, the hydrophilicity of graphene remains problematic, as it induced problems with stability. For this reason, the use of a chitosan coating remains one way to modify the surface features of graphene.

Method

In this investigation, a hybrid nanoparticle that consisted of a DOX-loaded reduced graphene oxide that is stabilized with chitosan (rGOD-HNP) was developed.

Result

The newly developed rGOD-HNP demonstrated high biocompatibility and efficiency in entrapping DOX (~65%) and releasing it in a controlled manner (~50% release in 48 h). Furthermore, it was also demonstrated that rGOD-HNP can intracellularly deliver DOX and more specifically in PC-3 prostate cancer cells.

Conclusion

This delivery tool offers a feasible and viable method to deliver DOX photo-thermally in the treatment of prostate cancer.

Multifunctional NaLnF4@MOF-Ln Nanocomposites with Dual-Mode Luminescence for Drug Delivery and Cell Imaging

Multifunctional nanomaterials for bioprobe and drug carrier have drawn great attention for their applications in the early monitoring the progression and treatment of cancers. In this work, we have developed new multifunctional water-soluble NaLnF₄@MOF-Ln nanocomposites with dual-mode luminescence, which is based on stokes luminescent mesoporous lanthanide metal-organic frameworks (MOFs-Y:Eu³⁺) and anti-stokes luminescent NaYF₄:Tm³⁺/Yb³⁺ nanoparticles. The fluorescence mechanism and dynamics are investigated and the applications of these nanocomposites as bioprobes and drug carriers in the cancer imaging and treatment are explored. Our results demonstrate that these nanocomposites with the excellent two-color emission show great potential in drug delivery, cancer cell imaging, and treatment, which are attributed to the unique spatial structure and good biocompatibility characteristics of NaLnF₄@MOF-Ln nanocomposites.

A green chemistry to produce iron oxide - Chitosan nanocomposite (CS-IONC) for the upgraded bio-restorative and pharmacotherapeutic activities - Supra molecular nanoformulation against drug-resistant pathogens and malignant growth

The logical research on fundamentally adjusted iron oxide nanoparticles has turned out to expanded in biomedicine because of the improved activity and best biocompatibility. In this present work upgraded bio-restorative and pharmacotherapeutic property of chitosan‑iron oxide nanocomposite, which was set up by eco-friendly in situ substance technique. Characterisation of the synthesised nanocomposite by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), x-ray diffraction,(XRD) and Vibrating test magnetometer (VSM) studies reveals that highly stable spherical, electron-dense core shelled rough particles of 50-60 nm. Particle morphology of the synthesised nanocomposite utilising scanning electron microscopy (SEM) uncovers spherical; thick electron centre shelled harsh particles with the size scope of 50-60 nm. FTIR studies show that the specific interaction of practical gatherings of chitosan with iron oxide nanoparticles. Crystalline phase and magnetisation impact of the composite resolved from XRD and VSM studies. Anti-bacterial activity of the nanocomposite examined against human bacterial pathogens which suggest that the readied nanocomposite successfully restrained the development of the tried bacterial strains by recording maximum zone of inhibition, least minimum inhibition concentration (MIC) and biofilm damage against the both tested strains. 100 μg dosages of nanocomposites recorded 20.0 and 21.0 mm of the zone of inhibition against E. coli and S. aureus respectively. Biofilm restraint was additionally observed to be high in nanocomposite treatment by recording lower optical density of ethanol solubilised biofilm of both tested strains. Anticancer activity was examined against the A549 cell line by the assurance of cell feasibility as opposed to oxidative proteins, articulation example of TNF-α, Bax, PARP qualities and apoptosis. Composite prompted 50% of cytotoxicity at 80 μg/mL unmistakably uncovers cytotoxicity against A549 cells. Nanocomposite treatment revealed a high decrease of cell feasibility at all the fixation and most extreme impact seen in 100 μg. Nanocomposite treated cells demonstrated striking changes in cell morphology, the build-up of atomic material related to trademark changes in against oxidative enzymes, quality articulation design which brought about apoptosis-like necrotic cell death. The present findings would propose the conceivable usage of chitosan‑iron oxide nanocomposite as a viable remedial against safe medication pathogens and malignant growth cells.

Recent Advances on Polymeric Beads or Hydrogels as Embolization Agents for Improved Transcatheter Arterial Chemoembolization (TACE)

Transcatheter arterial chemoembolization (TACE), aiming to block the hepatic artery for inhibiting tumor blood supply, became a popular therapy for hepatocellular carcinoma (HCC) patients. Traditional TACE formulation of anticancer drug emulsion in ethiodized oil (i.e., Lipiodol®) and gelatin sponge (i.e., Gelfoam®) had drawbacks on patient tolerance and resulted in undesired systemic toxicity, which were both significantly improved by polymeric beads, microparticles, or hydrogels by taking advantage of the elegant design of biocompatible or biodegradable polymers, especially amphiphilic polymers or polymers with both hydrophilic and hydrophobic chains, which could self-assemble into proposed microspheres or hydrogels. In this review, we aimed to summarize recent advances on polymeric embolization beads or hydrogels as TACE agents, with emphasis on their material basis of polymer architectures, which are important but have not yet been comprehensively summarized.

The Effect of Nanofillers on the Functional Properties of Biopolymer-based Films: A Review

Waste from non-degradable plastics is becoming an increasingly serious problem. Therefore, more and more research focuses on the development of materials with biodegradable properties. Bio-polymers are excellent raw materials for the production of such materials. Bio-based biopolymer films reinforced with nanostructures have become an interesting area of research. Nanocomposite films are a group of materials that mainly consist of bio-based natural (e.g., chitosan, starch) and synthetic (e.g., poly(lactic acid)) polymers and nanofillers (clay, organic, inorganic, or carbon nanostructures), with different properties. The interaction between environmentally friendly biopolymers and nanofillers leads to the improved functionality of nanocomposite materials. Depending on the properties of nanofillers, new or improved properties of nanocomposites can be obtained such as: barrier properties, improved mechanical strength, antimicrobial, and antioxidant properties or thermal stability. This review compiles information about biopolymers used as the matrix for the films with nanofillers as the active agents. Particular emphasis has been placed on the influence of nanofillers on functional properties of biopolymer films and their possible use within the food industry and food packaging systems. The possible applications of those nanocomposite films within other industries (medicine, drug and chemical industry, tissue engineering) is also briefly summarized.