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The smart manufacturing system can become a linked network with the help of the Internet of Things (IoT). Devices connected to the IoT are susceptible to various attacks and assaults. An effective protection plan is needed to ensure that the billions of IoT nodes are protected from these hazards. The security mechanisms on IoT devices are ineffective due to resource limitations. As a result, the academic community has recently paid attention to the cloud-, fog-, and edge-based IoT systems. A robust cloud provider is in the cloud or fog to perform computationally demanding activities, including safety, data analysis, decision-making process, and monitoring. Hash identities and upgraded Rivest–Shamir–Adleman (RSA) have been used to secure the IoT device’s data. A four-prime integer of 512 bits makes up the proposed security algorithm. A hash signature is used to provide device authentication. An effective clustering method for sensing devices based on the node level, separation from the clusters, remaining energy, and fitness has been presented for long network life. The suggested swarm-based method determines the sensor nodes’ fitness. A deep neural network- (DNN-) based resource scheduling algorithm (DNN-RSM) is meant to reduce the delay and communications overhead for IoT components in the hybrid cloud system. For optimum resource allocation, all queries originating from the cluster head are categorised using DNN based on their storage, processing, and bandwidth needs. The suggested structure delivers better outcomes, particularly regarding energy use, delay, and safety level. The results of the simulation provide credence to the concept that the proposed strategy is superior to the current system. The suggested scheme includes stringent security, decreased energy usage, decreased latency, and efficient resource utilization.

Tumor-associated macrophages (TAMs), which dampen the therapeutic efficacy of cancer immunotherapy, are the key players in the immunosuppressive tumor microenvironment (TME). Therefore, reprogramming TAMs into tumoricidal M1 macrophages possesses considerable potential as a novel immunotherapy. However, the low bioavailability of polarization agents and limited accumulation of TAMs restrict their anti-tumor efficacy. In this study, we developed a polymer-based hypoxia-responsive nanocomplex to target TAMs in hypoxia for enhanced cancer immunotherapy. We synthesized a hypoxia-cleavable polymer poly(ethylene glycol)-azo-poly(

Survival status of aqua fauna is estimated by studying the dynamic behaviour (motion) in underwater environment. Survival status of aqua fauna particularly, shrimp is estimated to prevent huge economic losses to the aqua farmers. A novel approach has been proposed in this research work to address this issue through segmentation, extraction of features, motion analysis and classification of aqua fauna from the pond aquaculture video sequences. First, the content-based video is translated into frames, and the image content is segmented using the Background Subtraction algorithm. Then, shrimp motion analysis is done with the assistance of the optical Flow algorithm. At the same time, shrimp body feature is extracted by Edge detection method for Shape analysis. Finally, the Decision Tree classifier is constructed to estimate the status of shrimp is alive or dead. Real-time video sequences of shrimp in pond aquaculture have illustrated the effectiveness of our process. The projected method shows that the results are more accurate to estimate the shrimp survival status as well as providing GMP (Good Manufacturing Practices) in shrimp cultivation to alert the aqua farmers in advance to avoid economic loss

The high activity of specific enzymes in cancer has been utilized in cancer diagnosis, as well as tumor-targeted drug delivery. NAD(P)H:quinone oxidoreductase-1 (NQO1), an overexpressed enzyme in certain tumor types, maintains homeostasis and inhibits oxidative stress caused by elevated reactive oxygen species (ROS) in tumor cells. The activity of NQO1 in lung and liver cancer cells is increased compared to that in normal cells. Interestingly, NQO1 reacts with trimethyl-locked quinone propionic acid (QPA) and produces a lactone-based group via intramolecular cyclization. Toward this objective, we synthesized an amphiphilic block copolymer (QPA-P) composed of NQO1 enzyme-triggered depolymerizable QPA-locked polycaprolactone (PCL) and poly(ethylene glycol) (PEG) as hydrophobic and hydrophilic constituents, respectively. This QPA-P formed self-assembled micelles in aqueous conditions. It was observed that NQO1 catalyzed the depolymerization of QPA-locked PCL via a cascade two-step cyclization process, which eventually induced the dissociation of micellar structure and triggered the release of loaded drugs at the target cancer cells. Compared to the control group, the NQO1-responsive micelle showed NQO1-triggered intracellular drug release and enhanced anticancer effects. These results indicate that the NQO1-responsive polymeric micelles present a promising potential for improving therapeutic efficacy of an anticancer drug delivery system.

In the present study, we report a rationally designed polymer/aptamer-integrated gold (Au) nanoconstruct capable of scavenging reactive oxygen species (ROS) and capturing tumor necrosis factor alpha (TNF-α) and investigate its potential as an anti-inflammatory agent for the treatment of peritonitis. By taking advantage of specific interactions between ATP and both ATP aptamer and polymeric phenylboronic acid (pPBA), we construct a unique polymer-coated Au nanoconstruct equipped with TNF-α aptamer and ATP aptamer. The formed phenylboronic ester and TNF-α aptamer in the nanoconstruct is capable of scavenging ROS and capturing of TNF-α, respectively. Thus, this combined characteristics enable the nanoconstruct an additive anti-inflammatory effect. Furthermore, we demonstrate the high anti-inflammatory effect of the nanoconstruct in vitro and in vivo using the peritonitis model by monitoring ROS and pro-inflammatory cytokine levels.

Human-computer interfaces (HCI) allow people to control electronic devices, such as computers, mouses, wheelchairs, and keyboards, by bypassing the biochannel without using motor nervous system signals. These signals permit communication between people and electronic-controllable devices. This communication is due to HCI, which facilitates lives of paralyzed patients who do not have any problems with their cognitive functioning. The major plan of this study is to test out the feasibility of nine states of HCI by using modern techniques to overcome the problem faced by the paralyzed. Analog Digital Instrument T26 with a five-electrode system was used in this method. Voluntarily twenty subjects participated in this study. The extracted signals were preprocessed by applying notch filter with a range of 50 Hz to remove the external interferences; the features were extracted by applying convolution theorem. Afterwards, extracted features were classified using Elman and distributed time delay neural network. Average classification accuracy with 90.82% and 90.56% was achieved using two network models. The accuracy of the classifier was analyzed by single-trial analysis and performances of the classifier were observed using bit transfer rate (BTR) for twenty subjects to check the feasibility of designing the HCI. The achieved results showed that the ERNN model has a greater potential to classify, identify, and recognize the EOG signal compared with distributed time delay network for most of the subjects. The control signal generated by classifiers was applied as control signals to navigate the assistive devices such as mouse, keyboard, and wheelchair activities for disabled people.

Engineering the membrane of the polymersomes with biologically relevant stimuli-responsive units enables spatial and temporal controlled drug release for effective therapy. Herein, we introduce a new-type of polymersomes featuring reactive oxygen species singlet oxygen (1O2)-labile membrane by employing a versatile stereoregular amphiphilic poly(ethylene glycol)-block-poly(β-aminoacrylate)-block-poly(ethylene glycol) copolymers, which are synthesized through a facile one pot modular amino-alkynoate click polymerization between secondary amines and activated alkynes. These polymersomes readily co-encapsulate an anticancer drug doxorubicin (DOX) and a near infrared (NIR) photosensitizer IR-780 with hydrophobic characteristics in the membrane, and the resulting polymersomes show efficient uptake by the tumor cells. NIR light irradiation on the tumors, following intraperitoneal injection of the IR-780/DOX co-encapsulated polymersomes, facilitates tumor-specific release of DOX through disassembly of the polymersome nanostructure via 1O2-mediated photocleavage of the membrane. Moreover, IR-780 dye can convert NIR light energy into heat in addition to the generation of 1O2, thus allows to realize both photothermal and photodynamic therapy. Accordingly, the NIR light-mediated on demand chemotherapy, in combination with appreciable phototherapy, of IR-780/DOX co-loaded polymersomes demonstrate an efficient tumor suppression in vivo.

Nitric oxide (NO) is one of the structurally smallest pharmaceutical molecules, which shows great potential as an anti-restenosis, wound healing, anticancer, and antibacterial agent. To date, while most of the studies have focused mainly on demonstrating the versatility of the NO-releasing materials, little effort has been made on developing successful NO-delivery strategies for advancing NO-mediated therapy. Thus, the quest for a rationally designed NO-delivery system is becoming one of the important issues in the biomedical applications of NO. This feature article discusses the overall research trends in the NO-delivery, focusing mainly on the various particle-type and coating platforms. The objective of this article is not only to highlight the fundamental principle and challenges associated with NO-delivery, but also to provide insight for the further development of novel NO-delivery platforms for clinical applications in the near future.

We have reported rational design of a polymeric NO delivery micelle as a cytosol-selective NO bomb. Protected NO-donors are released from the micelle under endolysosomal conditions, and then deprotected by cytosolic glutathione. Cytosol-selective NO delivery facilitates significant tumor regression without the aid of other therapeutic modalities even in intravenous administrations.

Incorporation of a desired stimuli-responsive unit in a stereospecific manner at the specific location within a nonlinear block copolymer architecture is a challenging task in synthetic polymer chemistry. Herein, we report a facile and versatile method to synthesize AB2 miktoarm block copolymers bearing a singlet oxygen (1O2)-labile regio and stereospecific β-aminoacrylate linkage with 100% E-configuration at the junction via a combination of amino-yne click chemistry and ring opening polymerization. Using this strategy, a series of 1O2-responsive AB2 amphiphilic miktoarm (MA) copolymers composed of hydrophilic polyethylene glycol (PEG) as the A constituent and hydrophobic polycaprolactone (PCL) as the B constituent (MA-PEG-b-PCL2) was synthesized by varying the block length of PCL. The self-assembly characteristics of these well-defined MA-PEG-b-PCL2 copolymers in an aqueous condition were studied by solvent displacement and thin-film hydration method, and their morphologies were investigated using trans...

Herein, we report the proof of concept of photoresponsive chemotherapeutics comprising nitric oxide-releasing platinum prodrugs and polymeric micelles. Photoactivatable nitric oxide-releasing donors were integrated into the axial positions of a platinum(IV) prodrug, and the photolabile hydrophobic groups were grafted in the block copolymers. The hydrophobic interaction between nitric oxide donors and the photolabile groups allowed for the loading of platinum drugs and nitric oxide-releasing donors in the photolabile polymeric micelles. After cellular uptake of micelles, light irradiation induced the release of nitric oxide, which sensitized the cancer cells. Simultaneously, photolabile hydrophobic groups were cleaved from micelles, and the nitric oxide-releasing donor was altered to be more hydrophilic, resulting in the rapid release of platinum(IV) prodrugs. The strategy of using platinum(IV) prodrugs and nitric oxide led to enhanced anticancer effects.

Nitric oxide (NO) is a signaling gas molecule that plays important roles in various physiological processes and also in cancer biology. Many of its functions are greatly dependent on its concentration and duration in vivo. However, the clinical applications of most of the available low-molecular-weight NO donors are limited by lower aqueous stability and poor bioavailability. Therefore, in recent years, a number of NO-delivering nanoplatforms have been designed by integrating NO donors with functional nanomaterials to improve the local concentration of NO at the targeted disease site, thereby leading to enhanced therapeutic effects. This chapter highlights the recent progress of NO-releasing functional nanoplatforms with a special emphasis on chemo- and radiotherapy.

The tumor microenvironment (TME), which is composed of cancer cells, stromal cells, immune cells, and extracellular matrices, plays an important role in tumor growth and progression. Thus, targeting the TME using a well-designed nano-drug delivery system is emerging as a promising strategy for the treatment of solid tumors. Compared to normal tissues, the TME presents several distinguishable physiological features such as mildly acidic pH, hypoxia, high level of reactive oxygen species, and overexpression of specific enzymes, that are exploited as stimuli to induce specific changes in the nanocarrier structures, and thereby facilitates target-specific delivery of imaging or chemotherapeutic agents for the early diagnosis or effective treatment, respectively. Recently, smart nanocarriers that respond to more than one stimulus in the TME have also been designed to elicit a more desirable spatiotemporally controlled drug release. This review highlights the recent progress in TME-sensitive nanocarriers designed for more efficient tumor therapy and imaging. In particular, the design strategies, challenges, and critical considerations involved in the fabrication of TME-sensitive nanocarriers, along with their in vitro and in vivo evaluations are discussed.

The formation of an immunological synapse (IS) on recognition of a cancer cell is the main mechanism underlying the natural killer (NK)-cell-mediated killing of tumor cells. Herein, an integrative strategy for cancer therapy against solid tumors is reported, in which alterations in the cleft of IS, following the secretion of acidic granular content, are utilized as a trigger for the delivery of chemotherapeutic drugs. NK cells are decorated with the IS-environment-responsive micellar system to ensure the release of the payload when they attack cancer cells. Using this strategy, the immunological cytotoxic killing effect of NK cells against solid tumors is reinforced with the site-specific diffusion of chemotherapeutic agents. Harnessing the intrinsic mechanism for the recognition of abnormal cells and the tumor-homing effect of NK cells limit the adverse systemic effects of chemotherapeutic drugs. This approach may provide a pragmatic platform for the universal and effective utilization of IS formation.

Nitric oxide (NO) is widely known as an effective vasodilator at low concentrations. Drug delivery systems combined with NO can dilate blood vessels surrounding tumor tissues, and the drug accumulation in tumors is accelerated by the enhanced permeability and retention effect, leading to an improvement in the anti-tumor effect. N-heterocyclic carbene-based NO donors (e.g., 1,3-bis-(2,4,6-trimethylphenyl)imidazolylidene nitric oxide (IMesNO) have been developed for stable NO storing in air and water, and NO release by thermolysis. Herein, we demonstrated on-demand NO release by high-intensity focused ultrasound (HIFU) as a stimulus, which generated high heat and exerted an ablation effect when treated in vivo. We demonstrated IMesNO to be a HIFU-responsive NO donor and its potential application in vivo using IMesNO-loaded micelles. Moreover, IMesNO-loaded micelles mixed with drug-loaded micelles (IMesNO/DOX@MCs) showed acceleration of drug accumulation in tumor sites and enhanced tumor growth inhibition. Thus, our findings suggest a potential clinical bioapplication of NO-releasing drug-loaded micelles owing to the therapeutic function of NO and HIFU treatment for anti-cancer therapy.

For drug delivery nanocarriers to be a safe and effective therapeutic option, blood stability, tumor-targetability, and intracellular drug release features should be considered. In this study, to develop a potent drug delivery carrier that can meet the multiple requirements, we engineered a bioreducible core-crosslinked polymeric micelle based on hyaluronic acid (CC-HAM) by a facile method using d , l -dithiothreitol in aqueous conditions. The CC-HAM exhibited enhanced structural stability under diluted conditions with PBS containing FBS or sodium dodecyl sulfates. We also successfully encapsulated doxorubicin (DOX), chosen as a hydrophobic anti-cancer drug, in CC-HAMs with high loading efficiency (> 80%). The drug release rate of CC-HAMs was rapidly accelerated in the presence of glutathione, whereas the drug release was significantly retarded in physiological buffer (pH 7.4). An in vivo biodistribution study demonstrated the superior tumor targetability of CC-HAMs to that of non-crosslinked HAMs, primarily ascribed to robust stability of CC-HAMs in the bloodstream. Notably, these results correspond with the improved pharmacokinetics and tumor accumulation of DOX-loaded CC-HAMs as well as their excellent therapeutic efficacy. Overall, these results suggest that the robust, bioreducible CC-HAM can be applied as a potent doxorubicin delivery carrier for targeted cancer therapy.

In an attempt to develop biostable nanoparticles (NPs) as potential carriers of anticancer drugs, we prepared a triblock copolymer that can self-assemble into NPs and be gold cross-linked in aqueous conditions. The triblock copolymer, composed of poly(e-caprolactone)-block-poly(2-(dimethylamino) ethyl methacrylate)-block-poly(ethylene glycol) (PCL-b-PDMAEMA-b-PEG), was synthesized by a combination of ring-opening polymerization, atom transfer radical polymerization and click chemistry. The chemical structures and compositions of the triblock copolymer and its intermediates were characterized by FT-IR and 1H NMR. The triblock copolymer formed spherical NPs (195 nm in diameter) in PBS (pH 7.4). The anticancer drug, doxorubicin (DOX), was loaded into the NPs using a dialysis method. Tertiary amine groups, present in the PDMAEMA block of the triblock polymer, were used for in situ gold cross-linking, which was confirmed using transmission electron microscopy and UV/VIS spectroscopy. Bare NPs released 80% of DOX over 6 days, whereas only 40% of the DOX was released from gold cross-linked NPs (GNPs), implying that the gold cross-links act as a diffusion barrier of DOX. Owing to the slow release of DOX, the cytotoxicity of DOX-GNPs was much lower than that of DOX-loaded bare NPs. The blood concentrations of DOX were also monitored after intravenous injection of free DOX and DOX-loaded NPs into the tail veins of rats. The results indicated that the blood circulation time of DOX was longest for DOX-GNP, followed by DOX-NP, and free DOX. Overall, DOX-GNPs may be a promising carrier for hydrophobic anticancer drugs.

Since most of the anticancer drugs exert their action in the intracellular environment, it is imperative to deliver them selectively inside the cancer cells for effective therapy. In an attempt to develop the potential carrier for intracellular drug delivery, we prepared the amphiphilic hyaluronic acid conjugate (HA-SS-DDT) bearing the disulfide bond which could be selectively cleaved at the intracellular environment. Owing to its amphiphilicity, the HA-SS-DDT conjugate formed self-assembled nanoparticles in an aqueous condition. The nanoparticles were stable under the physiological condition (pH 7.4, 37 °C) for at least five days. Doxorubicin (DOX), chosen as the model anticancer drug, was effectively encapsulated into HA-SS-DDT nanoparticles with high efficiency (>70%) by the oil-in-water emulsion method. In the physiological solution (PBS, pH 7.4), DOX was released from HA-SS-DDT nanoparticles in a sustained manner. Interestingly, in the presence of 10 mM glutathione, a peptide abundant in the cytoplasm of the cancer cell, the release rate of DOX remarkably increased, which was due to disintegration of nanoparticles by the cleavage of the disulfide bond. DOX-loaded HA-SS-DDT (HA-SS-DDT-DOX) nanoparticles were efficiently taken up by squamous cell carcinoma (SCC7) cells via receptor-mediated endocytosis, followed by rapid release of DOX in the cytoplasm of the cells. Overall, these results indicate that HA-SS-DDT nanoparticles have promising potential as the carrier for intracellular DOX delivery.

In recent years, hyaluronic acid (HA) has attracted significant interest in development of drug delivery systems because of its intrinsic physicochemical and biological properties, including water solubility, viscoeleasticity, non-immunogenicity, biocompatibility, and biodegradability. In addition, HA has the ability to selectively bind specific receptors on the disease-related cells such as cancer cells and activated macrophages, followed by receptor-mediated endocytosis. Owing to these unique features, HA has been extensively used for development of the targetable carriers to deliver the therapeutic and imaging agents. In this review, we discuss the recent progress in various HA-based conjugates for cancer therapy and imaging, in which the active agents are covalently conjugated or physically encapsulated.

The carboxymethyl dextran-y-cyclodextrin (CMD-yCD) conjugate was prepared as the carrier for the delivery of the poorly water-soluble anticancer drug, doxorubicin (DOX). The conjugate could form self-assembled nanoparticles (315 nm in diameter) in an aqueous solution, which might be due to the hydrogen bonding among yCD molecules in the conjugate. DOX was effectively encapsulated into CMD-yCD nanoparticles (CMD-NPs) by the emulsion method. In particular, regardless of the feed amount of DOX, its loading efficiencies were always greater than 70%. CMD-NPs released DOX in a sustained manner, owing to the inclusion complex formation between DOX and yCD. When Cy5.5-labeled CMD-NPs were treated with SCC7 cancer cells, strong fluorescence signals were observed at the cytosol, indicating effective intracellular uptake. In addition, DOX-loaded CMD-NPs exhibited dose-dependent cytotoxicity to SCC7 cancer cells. However, the empty nanoparticles did not show toxicity to the cells, implying their high biocompatibility. Overall, these results suggest that the CMD-gammaCD conjugate could be a useful carrier for the delivery of DOX.

The therapeutic efficacy of most drugs is greatly depends on their ability to cross the cellular barrier and reach their intracellular target sites. To transport the drugs effectively through the cellular membrane and to deliver them into the intracellular environment, several interesting smart carrier systems based on both synthetic or natural polymers have been designed and developed. In recent years, hyaluronic acid (HA) has emerged as a promising candidate for intracellular delivery of various therapeutic and imaging agents because of its innate ability to recognize specific cellular receptors that overexpressed on diseased cells. The aim of this review is to highlight the significance of HA in cancer, and to explore the recent advances of HA-based drug carriers towards cancer imaging and therapeutics.

An amphiphilic diblock copolymer bearing the reduction-sensitive linker, composed of poly(ethylene glycol) (PEG) and hydrophobic poly(γ-benzyl L-glutamate) (PBLG), was prepared as the potential carrier of doxo- rubicin (DOX) via a facile synthetic method in the presence of a shell-sheddable PEG macroinitiator (PEG-SS-NH2). Owing to its amphiphilic nature, the copolymer (PEG-SS-PBLG) formed spherical micelles (137 nm in diameter) in aqueous conditions. The micelles were stable under the physiologic condition (pH 7.4) and were readily cleaved in the presence of glutathione (GSH), a tripeptide reducing the disulfide bond in the cytoplasm of the cell. DOX, chosen as a model anticancer drug, was effectively encapsulated into the hydrophobic core of the micelle with high loading efficiency (>75%). The micelle released DOX completely within 18 h at 10 mM GSH mimicking the intracellular condition, whereas only 34% of the drug was released from the micelle at 2 µM GSH. In vitro cytotoxicity tests revealed that DOX-loaded reduction-sensitive micelles are more toxic to SCC7 cells than reduction-insensitive con- trol micelles. These results suggest that PEG-SS-PBLG is the promising carrier for the intracellular delivery of DOX.

Polysaccharide-based nanoparticles have attracted interest as carriers for imaging and therapeutic agents because of their unique physicochemical properties, including biocompatibility and biodegradability. In addition, the functional groups of the polysaccharide backbone allow facile chemical modification to develop nanoparticles with diverse structures. Some polysaccharides have the intrinsic ability to recognize specific cell types, facilitating the design of targeted-drug delivery systems through receptor-mediated endocytosis. The main objective of this review is to provide an overview of various polysaccharide-based nanoparticles and to highlight the recent efforts that have been made to improve the characteristics of polysaccharide-based nanoparticles for drug delivery and biomedical imaging.

This study developed new enzyme-specific superparamagnetic iron oxide nanoparticles (SPIONs) with potential as a multimodal probe in magnetic resonance (MR) imaging and optical imaging. For the MR/optical dual imaging, SPIONs were coated with near-infrared fluorescence dye (Cy5.5)-labeled hyaluronic acid (Cy5.5-HA), which could be readily degraded by hyaluronidase (HAdase). The presence of HA on the coated SPION was confirmed using FTIR, X-ray diffraction, and thermogravimetric analysis. Physicochemical analyses of Cy5.5-HA-coated SPIONs (Cy5.5-HA-SPIONs) demonstrated their higher colloidal stability and T2 relaxivity than bare SPIONs. When Cy5.5-HA-SPIONs were exposed to the MR instrument for the phantom test, the dark intensity of their T2-weighted image increased in a Fe concentration-dependent manner, suggesting potential as the MR probe. To examine their ability as the enzyme-sensitive optical probe, the fluorescent signals of Cy5.5-HA-SPIONs were measured in the absence or presence of HAdase. In the absence of HAdase, Cy5.5-HA-SPIONs showed a negligible fluorescent signal due to possible quenching between a SPION and fluorescence dye, and self-quenching effect of Cy5.5 molecules. On the other hand, in the presence of HAdase, the fluorescent signal of Cy5.5-HA-SPIONs increased dramatically as a function of the HAdase concentration, resulting from the degradation of the HA backbone. These results suggest that the Cy5.5-HA-SPION is useful as a multimodal nanoprobe for MR imaging and HAdase-sensitive optical imaging.

Amphiphilic hyaluronic acid conjugates were synthesized as a potential drug carrier by chemical conjugation of an amine-terminated hydrotropic oligomer, which has a unique ability to enhance the solubility of paclitaxel (PTX), to a hyaluronic acid (HA) backbone using carbodiimide chemistry. The physicochemical properties of the hydrotropic hyaluronic acid (HydroHA) conjugates were investigated using (1)H NMR, dynamic light scattering, transmission electron microscopy (TEM), and fluorescence spectroscopy. HydroHA conjugates could form self-assembled nanoparticles in an aqueous medium because of hydrophobic interactions among hydrotropic oligomers. Their particle sizes were in the range of 274-356nm, depending on the degree of substitution (DS) of the hydrotropic oligomer. TEM images showed that particle morphology was spherical in shape. Critical aggregation concentrations of HydroHA conjugates ranged from 0.034 to 0.125mg/mL, which decreased with an increase in the DS of the hydrotropic oligomer. The HydroHA conjugates were selectively taken up by the cancer cell line (SCC-7) over-expressing CD44, a hyaluronic receptor. The nanoparticles could encapsulate PTX up to 20.7wt.% by the dialysis method. The in vitro release pattern of PTX from nanoparticles was significantly dependent on drug loading content, in which the release rate was lower for the nanoparticles that contained larger amounts of the drug. From the cytotoxicity test, it was found that the drug-loaded HydroHA nanoparticles exhibited stronger cytotoxicity to SCC-7 than to normal fibroblast cell (CV-1). These results suggest that HydroHA nanoparticles have potential as the carrier of PTX for cancer therapy.

Chitosan has prompted the continuous impetus for the development of safe and effective drug delivery systems because of its unique physicochemical and biological characteristics. The primary hydroxyl and amine groups located on the backbone of chitosan allow for chemical modification to control its physical properties. When the hydrophobic moiety is conjugated to a chitosan molecule, the resulting amphiphile may form self-assembled nanoparticles that can encapsulate a quantity of drugs and deliver them to a specific site of action. Chemical attachment of the drug to the chitosan throughout the functional linker may produce useful prodrugs, exhibiting the appropriate biological activity at the target site. Mucoadhesive and absorption enhancement properties of chitosan increase the in vivo residence time of the dosage form in the gastrointestinal tract and improve the bioavailability of various drugs. The main objective of this review is to provide an insight into various target-specific carriers, based on chitosan and its derivatives, towards low molecular weight drug delivery. The first part of the review is concerned with the organ-specific delivery of low molecular drugs using chitosan and its derivatives. The subsequent section considers the recent developments of drug delivery carriers for cancer therapy with special focus on various targeting strategies.

Endothelium plays a vital role in various vascular functions, and its dysfunction is a key underlying process closely related to diverse array of diseases such as atherosclerosis and tumor. Therefore, early detection of endothelial dysfunction at the functional or molecular level is of high importance for effective therapy. Recent advances in nanotechnology and our understanding in cellular and molecular biology have provided various biomedical imaging modalities and nanosized multimodal imaging agents. Multimodal nanoparticles that encompass the targeting ligands and magnetic/optical imaging labels enable us to visualize the pathophysiological process of various diseases using multiple imaging techniques. To visualize the specific pathogenic process at the molecular level, the imaging probe needs to be surface-functionalized with specific affinity ligands such as monoclonal antibodies (mAb). Combining the functional imaging agents along with therapeutic drugs has great potential for effective early detection, accurate diagnosis, and treatment of disease. The current review will highlight the application of various nanoparticle-based imaging agents and their recent developments in diagnosing endothelium dysfunction with a special emphasis on atherosclerosis and cancer.