Nanozyme as a rising star for metabolic disease management

Nanozyme, characterized by outstanding and inherent enzyme-mimicking properties, have emerged as highly promising alternatives to natural enzymes owning to their exceptional attributes such as regulation of oxidative stress, convenient storage, adjustable catalytic activities, remarkable stability, and effortless scalability for large-scale production. Given the potent regulatory function of nanozymes on oxidative stress and coupled with the fact that reactive oxygen species (ROS) play a vital role in the occurrence and exacerbation of metabolic diseases, nanozyme offer a unique perspective for therapy through multifunctional activities, achieving essential results in the treatment of metabolic diseases by directly scavenging excess ROS or regulating pathologically related molecules. The rational design strategies, nanozyme-enabled therapeutic mechanisms at the cellular level, and the therapies of nanozyme for several typical metabolic diseases and underlying mechanisms are discussed, mainly including obesity, diabetes, cardiovascular disease, diabetic wound healing, and others. Finally, the pharmacokinetics, safety analysis, challenges, and outlooks for the application of nanozyme are also presented. This review will provide some instructive perspectives on nanozyme and promote the development of enzyme-mimicking strategies in metabolic disease therapy.

Potential of plant mediated biosynthesis of iron nanoparticles and their application in dye degradation process

In recent years, nanotechnology has emerged as cutting-edge technology with multifarious applications in a wide array of fields. Green synthesis of iron nanoparticles (FeNP) are an upcoming cost effective and eco-friendly technique and recently gained significant importance. In the present study, green FeNPs were prepared using leaf litter which is one of the major seasonal waste contributors in urban built-up areas. Shedding trees during winter months (January - March) were selected. Most abundant trees were Pongamia pinnata (Indian beech), Morus alba (mulberry), Prosopis juliflora (mesquite) and Kigelia africana (sausage tree). Synthesized FeNPs were further used for degrading two commercial dyes, eosin yellow and fuchsin basic, via Fenton's mechanism. The study showed that the prepared nanoparticles were of iron oxides, but also reported presence of polyphenols as a capping agent. Dye degradation efficiency of nanoparticles synthesized by P. pinnata leaf litter was recorded to be highest, whereas the efficiency of nanoparticles synthesized by K. africana leaf litter was lowest. Chances of iron leaching during dye degradation process was also tested and observed that Fe was present in treated water below the standard guidelines. Thus, FeNPs can serve as a low-cost solution to remediate water pollutants with a green approach. Implications: Nanoparticles prepared in the study were showed as a promising adsorbent and demonstrating high surface area and well-developed porosity. The prepared adsorbent will have a great impact on wastewater treatment technology and possible applications at a large scale. There are several applications of nanoparticles in pollution remediation and at the same time it can solve solid waste issues as it required to prepare nanoparticles. One of the major applications at policy level can be water pollution remediation which is urgently needed.

Hybrid Cyanine/Methotrexate Nanoparticles for Synergistic PDT/Chemotherapy of Breast Cancer

Typically, nanomedicine was prepared using a nanocarrier to load cargo for specific purposes. In this work, a carrier-free nanosystem for imaging and photodynamic (PDT)/chemo combination therapy was developed using simple self-assembly of a dye and a chemotherapeutic agent. The resulting nanoparticles (I₂-IR783/MTX@NPs) exhibited a spherical morphology with a size of 240.6 ± 2.5 nm. I₂-IR783/MTX@NPs had substantial internalization in 4T1 murine breast cancer cells and showed a synergistic anticancer effect after NIR light irradiation. Additionally, the 3D tumor model exhibits the same phototoxicity of nanoparticles as a 2D cell culture. The PDT efficiency of the nanosystem in the physiological environment was confirmed by the detection of intracellular reactive oxygen species as well as the live/dead viability/cytotoxicity assay following NIR light exposure. In addition, optical coherence tomography (OCT) was used as an alternative tool to monitor the response after treatment. Therefore, I₂-IR783/MTX@NPs show great potential use in theranostic application for breast cancer PDT-chemotherapy.

Optimization of methacrylated gelatin /layered double hydroxides nanocomposite cell-laden hydrogel bioinks with high printability for 3D extrusion bioprinting

Layered double hydroxides (LDHs) offer unique source of inspiration for design of bone mimetic biomaterials due to their superior mechanical properties, drug delivery capability and regulation cellular behaviors, particularly by divalent metal cations in their structure. Three-dimensional (3D) bioprinting of LDHs holds great promise as a novel strategy thanks to highly tunable physiochemical properties and shear-thinning ability of LDHs, which allow shape fidelity after deposition. Herein, we introduce a straightforward strategy for extrusion bioprinting of cell laden nanocomposite hydrogel bioink of gelatin methacryloyl (GelMA) biopolymer and LDHs nanoparticles. First, we synthesized LDHs by co-precipitation process and systematically examined the effect of LDHs addition on printing parameters such as printing pressure, extrusion rate, printing speed, and finally bioink printability in creating grid-like constructs. The developed hydrogel bioinks provided precise control over extrudability, extrusion uniformity, and structural integrity after deposition. Based on the printability and rheological analysis, the printability could be altered by controlling the concentration of LDHs, and printability was found to be ideal with the addition of 3 wt % LDHs. The addition of LDHs resulted in remarkably enhanced compressive strength from 652 kPa (G-LDH0) to 1168 kPa (G-LDH3). It was shown that the printed nanocomposite hydrogel scaffolds were able to support encapsulated osteoblast survival, spreading, and proliferation in the absence of any osteoinductive factors taking advantage of LDHs. In addition, cells encapsulated in G-LDH3 had a larger cell spreading area and higher cell aspect ratio than those encapsulated in G-LDH0. Altogether, the results demonstrated that the developed GelMA/LDHs nanocomposite hydrogel bioink revealed a high potential for extrusion bioprinting with high structural fidelity to fabricate implantable 3D hydrogel constructs for repair of bone defects.

Nucleic acid drug vectors for diagnosis and treatment of brain diseases

Nucleic acid drugs have the advantages of rich target selection, simple in design, good and enduring effect. They have been demonstrated to have irreplaceable superiority in brain disease treatment, while vectors are a decisive factor in therapeutic efficacy. Strict physiological barriers, such as degradation and clearance in circulation, blood-brain barrier, cellular uptake, endosome/lysosome barriers, release, obstruct the delivery of nucleic acid drugs to the brain by the vectors. Nucleic acid drugs against a single target are inefficient in treating brain diseases of complex pathogenesis. Differences between individual patients lead to severe uncertainties in brain disease treatment with nucleic acid drugs. In this Review, we briefly summarize the classification of nucleic acid drugs. Next, we discuss physiological barriers during drug delivery and universal coping strategies and introduce the application methods of these universal strategies to nucleic acid drug vectors. Subsequently, we explore nucleic acid drug-based multidrug regimens for the combination treatment of brain diseases and the construction of the corresponding vectors. In the following, we address the feasibility of patient stratification and personalized therapy through diagnostic information from medical imaging and the manner of introducing contrast agents into vectors. Finally, we take a perspective on the future feasibility and remaining challenges of vector-based integrated diagnosis and gene therapy for brain diseases.

Layered double hydroxide-based nanocomposite scaffolds in tissue engineering applications

Layered double hydroxides (LDHs), when incorporated into biomaterials, provide a tunable composition, controllable particle size, anion exchange capacity, pH-sensitive solubility, high-drug loading efficiency, efficient gene and drug delivery, controlled release and effective intracellular uptake, natural biodegradability in an acidic medium, and negligible toxicity. In this review, we study potential applications of LDH-based nanocomposite scaffolds for tissue engineering. We address how LDHs provide new solutions for nanostructure stability and enhance in vivo studies' success.

Advanced drug delivery applications of layered double hydroxide

Layered double hydroxides (LDHs), also known as anionic clays or hydrotalcite-like compounds, are a class of nanomaterials that attained great attention as a carrier for drug delivery applications. The lamellar structure of this compound exhibits a high surface-to-volume ratio which enables the intercalation of therapeutic agents and releases them at the target site, thereby reducing the adverse effect. Moreover, the intercalated drug can be released in a sustained manner, and hence the frequency of drug administration can be decreased. The co-precipitation, ion exchange, manual grinding, and sol-gel methods are the most employed for their synthesis. The unique properties like the ease of synthesis, low cost, high biocompatibility, and low toxicity render them suitable for biomedical applications. This review presents the advances in the structure, properties, method of preparation, types, functionalization, and drug delivery applications of LDH. Also, this review provides various new conceptual insights that can form the basis for new research questions related to the drug delivery applications of LDH.

New tricks of old drugs: Repurposing non-chemo drugs and dietary phytochemicals as adjuvants in anti-tumor therapies

Combination therapy has long been applied to enhance therapeutic effect and deal with the occurrence of multi-drug resistance in cancer treatment. However, the overlapping toxicity of multiple anticancer drugs to healthy tissues and increasing financial burden on patients emerged as major concerns. As promising alternatives to chemo agents, repurposed non-chemo drugs and dietary phytochemicals have been investigated as adjuvants to conventional anti-tumor therapeutics, offering a safe and economic strategy for combination therapy. In this review, we aim to highlight the advances in research about combination therapy using conventional therapeutics and repurposed drugs or phytochemicals for an enhanced anti-tumor efficacy, along with the mechanisms involved in the synergism. Beyond these, we outlined the potential challenges and solutions for clinical translation of the proposed combination therapy, providing a safe and affordable strategy to improve the reach of cancer therapy to low income regions with such new tricks of old drugs.

Preparation, characterization and in vitro antitumor activity evaluation of hyaluronic acid-alendronate-methotrexate nanoparticles

As an anti-metabolic drug, methotrexate (MTX) plays an important role in the treatment of various malignant tumors. However, several side effects such as low selectivity and high toxic of MTX limited its further applications. With aims to increase its accumulation in the tumor sites and reduce the toxicity of normal tissue nonspecific uptake, a self-assembled hyaluronic acid-alendronate-methotrexate nanoparticle (HA-ALN-MTX NPs) with a dual-tumor-targeted drug loaded system was designed and synthesized with an average particle size of 265.6 ± 13.3 nm. The advantage of this nanosystem is that the anticancer drug MTX can be used as a tumor-targeted ligand for folate acid receptors (FA), and hyaluronic acid (HA) can be used as another tumor targeted ligand for CD44 receptors. In vitro experiments confirmed that HA-ALN-MTX NPs has lower toxic effect on normal tissue cells HUVECs and has relatively high proliferation inhibition effect on tumor cells A549. Moreover, the inhibition effect could be adjusted by altering the dose of given drugs. All these results revealed that the prepared HA-ALN-MTX NPs could be selectively taken up by tumor cells by FA and CD44 receptor-mediated endocytosis. Therefore, self-assembled HA-ALN-MTX NPs targeted by these FA/CD44 receptors for anticancer drugs could act as effective antitumor drugs.

Layered double hydroxide nanostructures and nanocomposites for biomedical applications

Layered double hydroxide (LDH) nanostructures and related nanocomposites have attracted significant interest in biomedical applications including cancer therapy, bioimaging and antibacterial treatment. These materials hold great advantages including low cost and facile preparation, convenient drug loading, high drug incorporation capacity, good biocompatibility, efficient intracellular uptake and endosome/lysosome escape, and natural biodegradability in an acidic environment. In this review, we summarize the development of three types of LDH nanostructures including pristine LDH, surface modified LDH, and LDH nanocomposites for a range of biomedical applications. The advantages and disadvantages of LDH nanostructures and insights into the future development are also discussed.

Paclitaxel-tyroserleutide Conjugates Self-assembly into Nanocarrier for Drug Delivery

Background:

The drug-drug self-assembly was considered as a simple and efficient approach to prepare high drug loading nano-drug carriers and present new opportunities for cancer therapeutics. The strategy of PTX amphiphiles preparation would be a possible way to solve the poor water solubility of PTX.

Methods:

The PTX-YSL conjugate were synthesized and characterized. The PTX-YSL nanocarriers was prepared by a simple self-assembly method. In vitro cell studies and pharmacokinetic studies were evaluated for their in vitro anti-tumor activities and blood retention time.

Results:

The structures of PTX-YSL conjugate were confirmed by LC-MS, 1H NMR and FTIR. The size and morphology of the PTX-YSL self-assembled nanocarriers were observed with TEM and DLS. PTX-YSL nanocarriers could facilitate cellular uptake and had low cytotoxicity. PTX-YSL nanocarriers have longer blood retention for enhancing accumulation in the tumor tissues via EPR effect.

Conclusion:

This drug delivery system formed by PTX-YSL conjugates constitutes a promising and effective drug carrier in cancer therapy.

Fluorescent labelling in living dental pulp stem cells by graphene oxide quantum dots

Cellular labelling is possible to offer significant information after transplantation for the purpose of determining stem cell therapy's efficacy. According to the research, it has been reported that graphene oxide quantum dots (GOQDs) are a kind of healthy biological labelling agent for stem cells which show little cytotoxicity. GOQDs' interactions have been examined on the dental pulp stem cells (hDPSCs) of human beings for the purpose of investigating GOQD's biocompatibility and uptake and explored GOQDs' effects on hDPSCs' metabolic activity and the proliferation. According to the outcomes, GDQDs have been accepted by hDPSCs in a time-dependent and concentration-dependent behaviour. Moreover, no important changes have been discovered within hDOPSCs' proliferation, viability as well as metabolic activity after treatment with GOQDs. Therefore, such resources have shown that GOQDs can be multifunctional agents for cell therapy, drug delivery as well as cell imaging and also as outstanding candidates for labelling stem cells.

Mesoporous Silica Nanoparticles for Protein Protection and Delivery

Therapeutic proteins are widely used in clinic for numerous therapies such as cancer therapy, immune therapy, diabetes management and infectious diseases control. The low stability and large size of proteins generally compromise their therapeutic effects. Thus, it is a big challenge to deliver active forms of proteins into targeted place in a controlled manner. Nanoparticle based delivery systems offer a promising method to address the challenges. In particular, mesoporous silica nanoparticles (MSNs) are of special interest for protein delivery due to their excellent biocompatibility, high stability, rigid framework, well-defined pore structure, easily controllable morphology and tuneable surface chemistry. Therefore, enhanced stability, improved activity, responsive release, and intracellular delivery of proteins have been achieved using MSNs as delivery vehicles. Here, we systematically review the effects of various structural parameters of MSNs on protein loading, protection, and delivery performance. We also highlight the status of the most recent progress using MSNs for intracellular delivery, extracellular delivery, antibacterial proteins delivery, enzyme mobilization, and catalysis.

Construction of a biodegradable, versatile nanocarrier for optional combination cancer therapy

A novel biodegradable versatile nanocarrier (FA-CM) was fabricated based on the self-assembly of delaminated CoAl-layered double hydroxides (LDHs) and manganese dioxide (MnO₂) for optional combination cancer therapy. Biodegradation, versatility, targeting, bioimaging, in vitro cytotoxicity and in vivo antitumor efficacy were evaluated. The results showed that FA-CM could not only be effectively degraded into Co²⁺, Al³⁺ and Mn²⁺ to overcome the long-term toxic side effects, but also successfully load any positive-charged, negative-charged, hydrophilic, and hydrophobic drug, meeting the critical requirement of versatile nanocarrier. Meanwhile, the presence of FA led to the higher uptake efficiency, cytotoxicity, and excellent fluorescence imaging of FA-CM toward cancerous cells. In particular, FA-CM exhibited glutathione and pH dual-response drug release, avoiding any premature leakage and side effects. The applicability of the FA-CM was determined by co-loading hydrophilic (doxorubicin (DOX)) and hydrophobic drug (paclitaxel (PTX)) for synergistic combination chemotherapy. In vitro cytotoxicity evaluation and a xenograft tumor model of hepatoma showed that this combination exhibited more efficient anticancer effects compared with either free drug alone or the corresponding cocktail solutions. Especially, the ratios of DOX and PTX loaded on FA-CM could be tuned as needed. A powerful approach is provided for the design and preparation of a biodegradable versatile nanocarrier with targeted ability and excellent biocompatibility, which can be potentially applied in clinical practice and medical imaging. STATEMENT OF SIGNIFICANCE: Drug delivery nanocarriers that can transport an effective dosage of drug molecules to targeted cells and tissues have been extensively designed to overcome the adverse side effects and low effectiveness of conventional chemotherapy. However, lack of biodegradability and versatility existing in majority of nanocarriers limit their further clinical applications. Thus, constructing a novel biodegradable versatile nanocarrier that can carry various types of drugs, is in urgent need and more suitable for commercial production and clinical use. In this study, we developed a novel biodegradable versatile nanocarrier (FA-CM) based on the self-assembly of delaminated CoAl-layered double hydroxides (LDHs) and manganese dioxide (MnO₂) for optional combination cancer therapy. This work provides a new strategy for constructing versatile biodegradable platform for targeted drug delivery, which would have broad applications in cancer theranostics.

Hybrid films with excellent oxygen and water vapor barrier properties as efficient anticorrosive coatings

A hydrophobic film is fabricated by spin-coating of Tween 80 modified layered double hydroxide and polydimethylsiloxane alternately, which displays enhanced oxygen/water vapor barrier properties and anti-corrosion behavior toward metal substrates.

Anti-tumor Study of Chondroitin Sulfate-Methotrexate Nanogels

Self-assembly nanogels (NGs) were formed by bioconjugating methotrexate (MTX) with chondroitin sulfate (CS). MTX-CS NGs can greatly enhance the solubility and improve the delivery efficacy of MTX due to the CD44 binding property of CS. Vivo experiments revealed that MTX-CS NGs showed less toxicity than MTX. MTX-CS NGs can improve the anti-tumor effect while reducing the side effects of MTX. Due to their CD44 binding property, chondroitin sulfate-drug conjugates could be a promising and efficient platform for improving the solubility of sparingly soluble drug molecules as well as targeted delivery to cancer cells and tumor tissues.

A Novel Type of Aqueous Dispersible Ultrathin-Layered Double Hydroxide Nanosheets for in Vivo Bioimaging and Drug Delivery

Layered double hydroxide (LDH) nanoparticles have been widely used for various biomedical applications. However, because of the difficulty of surface functionalization of LDH nanoparticles, the systemic administration of these nanomaterials for in vivo therapy remains a bottleneck. In this work, we develop a novel type of aqueous dispersible two-dimensional ultrathin LDH nanosheets with a size of about 50 nm and a thickness of about 1.4 to 4 nm. We are able to covalently attach positively charged rhodamine B fluorescent molecules to the nanosheets, and the nanohybrid retains strong fluorescence in liquid and even dry powder form. Therefore, it is available for bioimaging. Beyond this, it is convenient to modify the nanosheets with neutral poly(ethylene glycol) (PEG), so the nanohybrid is suitable for drug delivery through systemic administration. Indeed, in the test of using these nanostructures for delivery of a negatively charged anticancer drug, methotrexate (MTX), in a mouse model, dramatically improved therapeutic efficacy is achieved, indicated by the effective inhibition of tumor growth. Furthermore, our systematic in vivo safety investigation including measuring body weight, determining biodistribution in major organs, hematology analysis, blood biochemical assay, and hematoxylin and eosin stain demonstrates that the new material is biocompatible. Overall, this work represents a major development in the path of modifying functional LDH nanomaterials for clinical applications.

MnAl Layered Double Hydroxide Nanoparticles as a Dual-Functional Platform for Magnetic Resonance Imaging and siRNA Delivery

Multifunctional nanoparticles for cancer theranosis have been widely explored for effective cancer detection and therapy. In this work, dually functionalised manganese-based layered double hydroxide nanoparticles (Mn-LDH) were examined as an effective anticancer drug/gene delivery system and for T₁ -weighted magnetic resonance imaging (MRI) in brain cancer theranostics. Such Mn-LDH have been shown to accommodate dsDNA/siRNAs and efficiently deliver them to Neuro-2a cells (N2a). Mn-LDH have also shown high biocompatibility with low cytotoxicity. Importantly, the cell-death siRNA (CD-siRNA) delivered with Mn-LDH more efficiently kills brain cancer cells than the free CD-siRNA. Moreover, Mn-LDH can act as excellent contrast agents for MRI, with an r₁ value of 4.47 mm^-1  s^-1 , which is even higher than that of commercial contrast agents based on Gd complexes (r₁ =3.4 mm^-1  s^-1 ). Altogether, the high delivery efficacy and MRI contrast capability make dual-functional Mn-LDH potential bimodal agents for simultaneous cancer diagnosis and therapy.

Multifunctional organic-inorganic hybrid nanoparticles and nanosheets based on chitosan derivative and layered double hydroxide: cellular uptake mechanism and application for topical ocular drug delivery

To study the cellular uptake mechanism of multifunctional organic-inorganic hybrid nanoparticles and nanosheets, new chitosan-glutathione-valine-valine-layered double hydroxide (CG-VV-LDH) nanosheets with active targeting to peptide transporter-1 (PepT-1) were prepared, characterized and further compared with CG-VV-LDH nanoparticles. Both organic-inorganic hybrid nanoparticles and nanosheets showed a sustained release in vitro and prolonged precorneal retention time in vivo, but CG-VV-LDH nanoparticles showed superior permeability in the isolated cornea of rabbits than CG-VV-LDH nanosheets. Furthermore, results of cellular uptake on human corneal epithelial primary cells (HCEpiC) and retinal pigment epithelial (ARPE-19) cells indicated that both clathrin-mediated endocytosis and active transport of PepT-1 are involved in the internalization of CG-VV-LDH nanoparticles and CG-VV-LDH nanosheets. In summary, the CG-VV-LDH nanoparticle may be a promising carrier as a topical ocular drug delivery system for the treatment of ocular diseases of mid-posterior segments, while the CG-VV-LDH nanosheet may be suitable for the treatment of ocular surface diseases.

Overcoming multidrug resistance through co-delivery of ROS-generating nano-machinery in cancer therapeutics

The use of nanotechnology to overcome multidrug resistance (MDR) in cancer cells has been predominant.

Firmly anchored photosensitizer Chlorin e6 to layered double hydroxide nanoflakes for highly efficient photodynamic therapy in vivo

We covalently conjugate photosensitizer Chlorin e6 (Ce6) to polyethylene glycol modified layered double hydroxides and produce hybrid nanoflakes with excellentin vivophotodynamic therapeutic efficiency and safety profiles.

Diamond nanostructures for drug delivery, bioimaging, and biosensing

This review summarizes the superior properties of diamond nanoparticles and vertically aligned diamond nanoneedles and their applications in biosensing, bioimaging and drug delivery.

Polymeric Nanohybrids as a New Class of Therapeutic Biotransporters

A possible solution to enhance existing drug and gene therapies is to develop hybrid nanocarriers capable of delivering therapeutic agents in a controlled and targeted manner. This goal can be achieved by designing nanohybrid systems, which combine organic or inorganic nanomaterials with biomacromolecules into a single composite. The unique combination of properties along with their facile fabrication enables the design of smart carriers for both drug and gene delivery. These hybrids can be further modified with cell targeting motifs to enhance their biological interactivity. In this Talents and Trends article, an overview of emerging nanohybrid-based technologies will be provided to highlight their potential use as innovative platforms for improved cancer therapies and new strategies in regenerative medicine. The clinical relevance of these systems will be reviewed to define the current challenges which still need to be addressed to allow these therapies to move from bench to bedside.

Hierarchical layered double hydroxide nanocomposites: structure, synthesis and applications

Layered double hydroxide (LDH)-based nanocomposites, constructed by interacting LDH nanoparticles with other nanomaterials (e.g. silica nanoparticles and magnetic nanoparticles) or polymeric molecules (e.g. proteins), are an emerging yet active area in healthcare, environmental remediation, energy conversion and storage. Combining advantages of each component in the structure and functions, hierarchical LDH-based nanocomposites have shown great potential in biomedicine, water purification, and energy storage and conversion. This feature article summarises the recent advances in LDH-based nanocomposites, focusing on their synthesis, structure, and application in drug delivery, bio-imaging, water purification, supercapacitors, and catalysis.

How successful is nuclear targeting by nanocarriers?

The nucleus is ultimately the final target for many therapeutics treating various disorders including cancers, heart dysfunction and brain disorders. Owing to their specialized cell uptake and trafficking mechanisms, nanoparticles (NPs) allow drug targeting where degradation sensitive therapeutics could be delivered to their target tissues and cell in active form and sufficient concentration. However, it has recently become increasingly obvious that cytosolic internalization of a drug molecule does not entail its interaction with its subcellular target and hence careful nanoparticle design and optimization is required to enable nuclear targeting. This review, discusses the barriers to NP nuclear delivery; crossing the cell membrane, endo/lysosomal escape, cytoplasmic trafficking and finally nuclear entry focusing on how NP synthesis and modification could allow for bypassing each of the aforementioned barriers and successfully reaching the nucleus. Examples of nuclear targeted NPs are also discussed, stressing on the critical aspects of nuclear targeting and pointing out how the disease state might change the normal NP path and how such change could be exploited to increase efficiency of nuclear targeting. Finally, the criteria set for the evaluation of nanocarriers for nuclear delivery are discussed highlighting that quantitative rather than qualitative evaluation is required to evaluate how successful nanocarriers for nuclear delivery are, particularly with regards to the amount of drug delivered and released in the nucleus.

A layered drug nanovehicle toward targeted cancer imaging and therapy

A layered drug nanovehicle with superior anticancer performance was fabricated via the co-intercalation of doxorubicin (DOX) and folic acid (FA) into the gallery of layered double hydroxides (LDHs), which can be potentially applied in medical imaging/therapy.

Layered double hydroxide nanoparticles to enhance organ-specific targeting and the anti-proliferative effect of cisplatin

The role of nanoparticle charge in biodistribution is evaluated by modifying the external surface of layered double hydroxides with various charges and a fluorescent dye (Cy5.5) is doped to assess the biodistribution.

Dexamethasone sodium phosphate intercalated layered double hydroxides and their therapeutic efficacy in a murine asthma model

Schematic diagram showing the intercalation of Dexa into the MgAl–LDH interlayers.

Targeted delivery of Doxorubicin by folic acid-decorated dual functional nanocarrier

Doxorubicin (DOX) is one of the most commonly used antineoplastic agents, but its clinical application is oftentimes coupled with severe side effects. Selective delivery of DOX to tumors via nanosized drug carrier represents an attractive approach to this problem. Previously, we developed a dual functional nanomicellar carrier, PEG5K-embelin2 (PEG5K-EB2), which was able to deliver paclitaxel (PTX) selectively to tumors and to achieve an enhanced therapeutic effect. In the present study, we examined the utility of PEG5K-EB2 to deliver DOX to tumors. In addition, folic acid (FA) was coupled to the surface of the PEG5K-EB2 micelles (FA-PEG5K-EB2) to further improve the selective targetability of the system. DOX-loaded PEG5K-EB2 micelles were uniformly spherical particles with a diameter of approximately 20 nm. Incorporation of FA had minimal effect on the size of the particles. The DOX loading efficiency was as high as 91.7% and 93.5% for PEG5K-EB2 and FA-PEG5K-EB2, respectively. DOX formulated in PEG5K-EB2 micelles (with or without FA decoration) demonstrated sustained kinetics of DOX release compared to free DOX. FA-PEG5K-EB2 significantly facilitated the intracellular uptake of DOX over free DOX and PEGylated liposomal DOX (Doxil) in breast cancer cells, 4T1.2, and drug resistant cells, NCI/ADR-RES. P-gp ATPase assay showed that PEG5K-EB2 significantly inhibited the function of the P-gp efflux pump. The maximum tolerated dose of DOX-loaded PEG5K-EB2 micelles was 15 mg/kg in mice, which was 1.5-fold greater than that for free DOX. Pharmacokinetics (PK) and biodistribution studies showed that both types of DOX-loaded micelles, especially FA-PEG5K-EB2, were able to significantly prolong the blood circulation time of DOX and facilitate its preferential accumulation at the tumor tissue. Finally, DOX/PEG5K-EB2 mixed micelles demonstrated significantly enhanced tumor growth inhibitory effect with minimal toxicity in comparison to free DOX and Doxil and the antitumor activity was further enhanced after the decoration by folic acid. Our data suggest that FA-PEG5K-EB2 micelles represent a promising DOX delivery system that warrants more study in the future.

Advanced materials and nanotechnology for drug delivery

Many biological barriers are of great importance. For example, stratum corneum, the outmost layer of skin, effectively protects people from being invaded by external microorganisms such as bacteria and viruses. Cell membranes help organisms maintain homeostasis by controlling substances to enter and leave cells. However, on the other hand, these biological barriers seriously restrict drug delivery. For instance, stratum corneum has a very dense structure and only allows very small molecules with a molecular weight of below 500 Da to permeate whereas most drug molecules are much larger than that. A wide variety of drugs including genes needs to enter cells for proper functioning but cell membranes are not permeable to them. To overcome these biological barriers, many drug-delivery routes are being actively researched and developed. In this research news, we will focus on two advanced materials and nanotechnology approaches for delivering vaccines through the skin for painless and efficient immunization and transporting drug molecules to cross cell membranes for high-throughput intracellular delivery.

Layered double hydroxide-based nanocarriers for drug delivery

Biocompatible clay materials have attracted particular attention as the efficient drug delivery systems (DDS). In this article, we review developments in the use of layered double hydroxides (LDHs) for controlled drug release and delivery. We show how advances in the ability to synthesize intercalated structures have a significant influence on the development of new applications of these materials. We also show how modification and/or functionalization can lead to new biotechnological and biomedical applications. This review highlights the most recent progresses in research on LDH-based controlled drug delivery systems, focusing mainly on: (i) DDS with cardiovascular drugs as guests; (ii) DDS with anti-inflammatory drugs as guests; and (iii) DDS with anti-cancer drugs as guests. Finally, future prospects for LDH-based drug carriers are also discussed.

A folic acid conjugated silica–titania porous hollow nanosphere for improved topical photodynamic therapy

The folic acid conjugated hollow nanosphere is used to encapsulate protoporphyrin IX and is utilized for photodynamic therapy.