Polymeric nanoparticles based on chitooligosaccharide as drug carriers for co-delivery of all-trans-retinoic acid and paclitaxel

Hemocompatible and biocompatible hybrid nanocarriers for enhanced oral bioavailability of paclitaxel: in vivo evaluation

Oral administration of BCS class IV anticancer agents has always remained challenging and frequently results in poor oral bioavailability. The goal of the current study was to develop hybrid nanoparticles (HNPs) employing cholesterol and poloxamer-407 to boost paclitaxel's (PTX) oral bioavailability. A series of HNPs with different cholesterol and poloxamer-407 ratios were developed utilizing a single-step nanoprecipitation technique. The PTX loaded HNPs were characterized systematically via particle size, zeta potential, polydispersity index, surface morphology, in vitro drug release, FTIR, DSC, XRD, acute oral toxicity analysis, hemolysis evaluation, accelerated stability studies, and in vivo pharmacokinetic analysis. The HNPs were found within the range of 106.6±55.60 - 244.5±88.24 nm diameter with the polydispersity index ranging from 0.20±0.03 - 0.51±0.11. SEM confirmed circular, nonporous, and smooth surfaces of HNPs. PTX loaded HNPs exhibited controlled release profile. The compatibility between the components of formulation, thermal stability, and amorphous nature of HNPs were confirmed by FTIR, DSC, and XRD, respectively. Acute oral toxicity analysis revealed that developed system have no deleterious effects on the animals' cellular structures. HNPs demonstrated notable cytotoxic effects and were hemocompatible at relatively higher concentrations. In vivo pharmacokinetic profile (AUC0-∞, AUMC0-∞, t1/2, and MRT0-∞) of the PTX loaded HNPs was improved as compared to pure PTX. It is concluded from our findings that the developed HNPs are hemocompatible, biocompatible and have significantly enhanced the oral bioavailability of PTX.

Selenizing chitooligosaccharide with site-selective modification to alleviate acute liver injury in vivo

Two selenized chitooligosaccharide (O-Se-COS and N,O-Se-COS) with different sites modification were synthesized to alleviate liver injury in vivo. Comparing to traditional COS, both selenized COS exhibited enhanced reducibility as well as antioxidant capacity in vitro. Furthermore, O-Se-COS demonstrated superior efficacy in reducing intracellular reactive oxygen species (ROS) and mitochondrial damage compared to N,O-Se-COS as its enhanced cellular uptake by the positive/negative charge interactions. Two mechanisms were proposed to explained these results: one is to enhance the enzymatic activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), which effectively scavenge free radicals; the other is to down-regulate intracellular cytochrome P450 (CYP2E1) levels, inhibiting carbon tetrachloride (CCl4)-induced peroxidation damage. In vivo studies further demonstrated the effective alleviation of CCl4-induced liver injury by selenized COS, with therapeutic efficacy observed in the following order: O-Se-COS > N,O-Se-COS > COS. Finally, hemolysis and histological tests confirmed the biosafety of both selenized COS. Taken together, these finding demonstrated that selenium has the potential to improve the biological activity of COS, and precise selenylation was more conducive to achieving the synergistic effect where 1 + 1>2.

Anti-cancer Activity of Biogenic Nat-ZnO Nanoparticles Synthesized Using Nyctanthes arbor-tristis (Nat) Flower Extract

Inorganic nanoparticles (NPs) have played an important role as nano-drug delivery systems during cancer therapy in recent years. These NPs can carry cancer therapeutic agents. Due to this, they are considered a promising ancillary to traditional cancer therapies. Among inorganic NPs, Zinc Oxide (ZnO) NPs have been extensively utilized in cellular imaging, gene/drug delivery, anti-microbial, and anti-cancerous applications. In this study, a rapid and cost-effective method was used to synthesize Nat-ZnO NPs using the floral extract of the Nyctanthes arbor-tristis (Nat) plant. Nat-ZnO NPs were physicochemically characterized and tested further on in vitro cancer models. The average hydrodynamic diameter (Zaverage) and the net surface charge of Nat-ZnO NPs were 372.5 ± 70.38 d.nm and -7.03 ± 0.55 mV, respectively. Nat-ZnO NPs exhibited a crystalline nature. HR-TEM analysis showed the triangular shape of NPs. Furthermore, Nat-ZnO NPs were also found to be biocompatible and hemocompatible when tested on mouse fibroblast cells and RBCs. Later, the anti-cancer activity of Nat-ZnO NPs was tested on lung and cervical cancer cells. These NPs displayed potent anti-cancer activity and induced programmed cell death in cancer cells.

Targeting active sites of inflammation using inherent properties of tissue-resident mast cells

Mast cells play a pivotal role in initiating and directing host's immune response. They reside in tissues that primarily interface with the external environment. Activated mast cells respond to environmental cues throughout acute and chronic inflammation through releasing immune mediators via rapid degranulation, or long-term de novo expression. Mast cell activation results in the rapid release of a variety of unique enzymes and reactive oxygen species. Furthermore, the increased density of mast cell unique receptors like mas related G protein-coupled receptor X2 also characterizes the inflamed tissues. The presence of these molecules (either released mediators or surface receptors) are particular to the sites of active inflammation, and are a result of mast cell activation. Herein, the molecular design principles for capitalizing on these novel mast cell properties is discussed with the goal of manipulating localized inflammation. STATEMENT OF SIGNIFICANCE: Mast cells are immune regulating cells that play a crucial role in both innate and adaptive immune responses. The activation of mast cells causes the release of multiple unique profiles of biomolecules, which are specific to both tissue and disease. These unique characteristics are tightly regulated and afford a localized stimulus for targeting inflammatory diseases. Herein, these important mast cell attributes are discussed in the frame of highlighting strategies for the design of bioresponsive functional materials to target regions of inflammations.

Potential Role of Growth Factors Controlled Release in Achieving Enhanced Neuronal Trans-differentiation from Mesenchymal Stem Cells for Neural Tissue Repair and Regeneration

With an increase in the incidence of neurodegenerative diseases, a need to replace incapable conventional methods has arisen. To overcome this burden, stem cells therapy has emerged as an efficient treatment option. Endeavours to accomplish this have paved the path to neural regeneration through efficient neuronal transdifferentiation. Despite their potential, the use of stem cells still entails several limitations, such as low differentiation efficiency and difficulties in guiding differentiation. The process of neural differentiation through the stem cells is achieved through the use of chemical inducers or growth factors and their direct introduction reduces their bioavailability in the system. To address these limitations, neural regeneration ventures require growth factors to be effectively implemented on stem cells in order to produce functional neuronal precursor cells. An efficient technique to achieve it is through the delivery of growth factors via microcarriers for their sustained release. It ensures the presence of commensurable concentration even at later stages of neuronal transdifferentiation. Nanofibers and nanoparticles, along with liposomes and such, have been used to implement this. The interaction between such carriers and the growth factors is mainly electrostatic. Such interaction enables them to form a stable assembly through immobilisation of the growth factor either onto their surfaces or within the core of their structures. The rate of sustained release depends upon the release kinetics associated with the polymeric structure employed and its interaction with the encapsulated growth factor. The sustained release ensures that the stem cells immerse under the effect of the growth factors for a prolonged period, ultimately aiding in the formation of cells showing ample characteristics of neuron precursors. This review analyses the various carriers that have been employed for the release of growth factors in an orderly fashion and their constituents, along with the advantages and the limitations they pose in delivering the growth factors for facilitating the process of neuronal transdifferentiation.

Balanced lipase interactions for degradation-controlled paclitaxel release from lipid cubic phase formulations

Lipid cubic phase (LCP) formulations enhance the intestinal solubility and bioavailability of hydrophobic drugs by reducing precipitation and facilitating their mass transport to the intestinal surface for absorption. LCPs with an ester linkage connecting the acyl chain to the glycerol backbone (monoacylglycerols), are susceptible to chemical digestion by several lipolytic enzymes including lipases, accelerating the release of hydrophobic agents from the lipid bilayers of the matrix. Unlike regular enzymes that transform soluble substrates, lipolytic enzymes act at the interface of water and insoluble lipid. Therefore, compounds that bind to this interface can enhance or inhibit the activity of enzymes to varying extent. Here, we explore how the lipolysis rate can be tuned by the interfacial interaction of porcine pancreatic lipase with monoolein LCPs containing a known lipase inhibitor, tetrahydrolipstatin. Release of the Biopharmaceutical Classification System (BCS) class IV drug, paclitaxel, from the inhibitor-modified LCP was examined in the presence of lipase and its effectors colipase and calcium. By combining experimental dynamic digestion studies, thermodynamic measurements and molecular dynamics simulations of the competitive inhibition of lipase by tetrahydrolipstatin, we reveal the role and mode of action of lipase effectors in creating a precisely-balanced degradation-controlled LCP release system for the poorly soluble paclitaxel drug.

Sustained-Release and pH-Adjusted Alginate Microspheres-Encapsulated Doxorubicin Inhibit the Viabilities in Hepatocellular Carcinoma-Derived Cells

The objective of this study aimed to develop biodegradable calcium alginate microspheres carrying doxorubicin (Dox) at the micrometer-scale for sustained release and the capacity of pH regulatory for transarterial chemoembolization. Ultrasonic atomization and CaCl₂ cross-linking technologies were used to prepare the microspheres. A 4-by-5 experiment was first designed to identify imperative parameters. The concentration of CaCl₂ and the flow rate of the pump were found to be critical to generate microspheres with a constant volume median diameter (~39 μm) across five groups with different alginate: NaHCO₃ ratios using each corresponding flow rate. In each group, the encapsulation efficiency was positively correlated to the Dox-loading %. Fourier-transform infrared spectroscopy showed that NaHCO₃ and Dox were step-by-step incorporated into the calcium alginate microspheres successfully. Microspheres containing alginate: NaHCO₃ = 1 exhibited rough and porous surfaces, high Young’s modulus, and hardness. In each group with the same alginate: NaHCO₃ ratio, the swelling rates of microspheres were higher in PBS containing 10% FBS compared to those in PBS alone. Microspheres with relatively high NaHCO₃ concentrations in PBS containing 10% FBS maintained better physiological pH and higher accumulated Dox release ratios. In two distinct hepatocellular carcinoma-derived cell lines, treatments with microspheres carrying Dox demonstrated that the cell viabilities decreased in groups with relatively high NaHCO₃ ratios in time- and dose-dependent manners. Our results suggested that biodegradable alginate microspheres containing relatively high NaHCO₃ concentrations improved the cytotoxicity effects in vitro.

The novel nanocomplexes containing deoxycholic acid-grafted chitosan and oleanolic acid displays the hepatoprotective effect against CCl4-induced liver injury in vivo

Chemical liver injury threatens seriously human health, along with the shortage of efficiency and low-toxicity drugs. Herein, the novel oral nanocomplexes composed of deoxycholic acid-grafted chitosan and oleanolic acid were constructed to reverse the CCl₄-induced acute liver damage in mice. Results indicated core-shell nanocomplexes, maintained by the hydrophobic interaction between deoxycholic acid and oleanolic acid, could be dissociated in the intestine. Notably, the nanocomplexes possessed superior hepatoprotective effect in vivo, possibly due to the synergistic effect between grafted chitosan and oleanolic acid. Mechanism investigations suggested that nanocomplexes reversed CCl₄-induced liver injury through improving hepatic antioxidant capacity via NrF2/Keap1 pathway and regulating inflammation response via NF-κB signaling pathway. The novel oral nanocomplexes represent an effective strategy for chemical liver injury therapy.

Self-Assembled pH-Sensitive Polymeric Nanoparticles for the Inflammation-Targeted Delivery of Cu/Zn-Superoxide Dismutase

The use of superoxide dismutase (SOD) is currently limited by its short half-life, rapid plasma clearance rate, and instability. We synthesized a small library of biofriendly amphiphilic polymers that comprise methoxy poly(ethylene glycol)-poly(cyclohexane-1,4-diyl acetone dimethyleneketal) (mPEG-PCADK) and mPEG-poly((cyclohexane_86.7%, 1,5-pentanediol_13.3%)-1,4-diyl acetone dimethylene ketal) (PK3) for the targeted delivery of SOD. The novel polymers could self-assemble into micellar nanoparticles with favorable hydrolysis kinetics, biocompatibility, long circulation time, and inflammation-targeting effects. These materials generated a better pH-response curve and exhibited better hydrolytic kinetic behavior than PCADK and PK3. The polymers showed good biocompatibility with protein drugs and did not induce an acidic microenvironment during degradation in contrast to materials such as PEG-block-poly(lactic-co-glycolic acid) (PLGA) and PLGA. The SOD that contained reverse micelles based on mPEG2000-PCADK exhibited good circulation and inflammation-targeting properties. Pharmacodynamic results indicated exceptional antioxidant and anti-inflammatory activities in a rat adjuvant-induced arthritis model and a rat peritonitis model. These results suggest that these copolymers are ideal protein carriers for targeting inflammation treatment.

Optimization of the spherical integrity for sustained-release alginate microcarriers-encapsulated doxorubicin by the Taguchi method

This study aimed to develop biodegradable calcium alginate microcarriers with uniform particle size and spherical integrity for sustained-release targeting transarterial chemoembolization. To determine related parameters including the ratio of cross-linking volume (sodium alginate: CaCl₂), concentrations of sodium alginate and CaCl₂ solutions, collection distance, flow rate, stirring speed, syringe needle diameter and hardening time to fabricate the microcarriers, the Taguchi method was applied. Using different conditions, a total of 18 groups were prepared. The average size of microspheres from different groups was estimated as ~ 2 mm (range 1.1 to 1.6 mm). Signal-to-noise ratio analysis showed the optimal spherical integrity (F1) achieved when the above parameters were designed as 0.1, 2.5 wt%, 6 wt%, 8 cm, 30 mL/h, 150 rpm, 0.25 mm and 2 h, respectively. The best (F1), middle (F2) and worst (F3) groups were used for further experiments. Fourier-transform infrared spectroscopy spectrum showed that F1, F2 and F3 conformations were distinct from original sodium alginate. Drug-loaded calcium alginate microcarriers demonstrated rougher surfaces compared to microspheres without drug under transmission electron microscopy. Compared to pH 7.4, swelling rates in PBS were decreased at pH 6.5. Encapsulation and loaded efficiencies of the Dox-loaded microcarriers were estimated as ~ 40.617% and ~ 3.517%. In vitro experiments indicated that the F1 Dox-loaded microcarriers provide a well sustained-release efficacy for about two weeks at 37 °C in PBS. Treatments of calcium alginate microcarriers without the Dox in two distinct hepatocellular carcinoma-derived cell lines, Huh-7 and Hep-3B, indicated that these microcarriers were non-toxic. The Dox-loaded microcarriers displayed sustained-release capacity and reduced cell viabilities to ~ 30% in both cell lines on Day 12.

l-Carnitine conjugated chitosan-stearic acid polymeric micelles for improving the oral bioavailability of paclitaxel

A delivery system based on l-carnitine (LC) conjugated chitosan (CS)-stearic acid polymeric micelles has been developed for improving the oral bioavailability of paclitaxel (PTX) through targeting intestinal organic cation/carnitine transporter 2 (OCTN2). Stearic acid grafted chitosan (CS-SA), as micelle skeleton material, was synthesized by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)-mediated coupling reaction. The PTX-loaded micelles were prepared by solvent evaporation-hydration method, and the ligand LC was conjugated onto the micelle surface by anchoring its derivative stearoyl group to the lipophilic core of micelle. The modified polymeric micelles showed regular spherical shapes with small particle size of 157.1 ± 5.2 nm and high drug loading capacity of 15.96 ± 0.20 wt%, and the micelle stability in water was supported by low critical micelle concentration of 14.31 ± 0.21 μg/ml. The drug-loaded micelles presented a slow and incomplete in vitro release, and the pharmacokinetic studies indicated the micelle carriers increased the relative bioavailability of PTX to 165.8% against the commercial formulation. The enhancement effect on intestinal absorption was also confirmed by the intracellular uptake of Caco-2 cells. The proposed micelle carrier system manifested a prospective tool for oral drug delivery.

Novel Potential Application of Chitosan Oligosaccharide for Attenuation of Renal Cyst Growth in the Treatment of Polycystic Kidney Disease

Chitosan oligosaccharide (COS), a natural polymer derived from chitosan, exerts several biological activities including anti-inflammation, anti-tumor, anti-metabolic syndrome, and drug delivery enhancer. Since COS is vastly distributed to kidney and eliminated in urine, it may have a potential advantage as the therapeutics of kidney diseases. Polycystic kidney disease (PKD) is a common genetic disorder characterized by multiple fluid-filled cysts, replacing normal renal parenchyma and leading to impaired renal function and end-stage renal disease (ESRD). The effective treatment for PKD still needs to be further elucidated. Interestingly, AMP-activated protein kinase (AMPK) has been proposed as a drug target for PKD. This study aimed to investigate the effect of COS on renal cyst enlargement and its underlying mechanisms. We found that COS at the concentrations of 50 and 100 µg/mL decreased renal cyst growth without cytotoxicity, as measured by MTT assay. Immunoblotting analysis showed that COS at 100 µg/mL activated AMPK, and this effect was abolished by STO-609, a calcium/calmodulin-dependent protein kinase kinase beta (CaMKKβ) inhibitor. Moreover, COS elevated the level of intracellular calcium. These results suggest that COS inhibits cyst progression by activation of AMPK via CaMKKβ. Therefore, COS may hold the potential for pharmaceutical application in PKD.

Biodegradable nanocarriers based on chitosan-modified mesoporous silica nanoparticles for delivery of methotrexate for application in breast cancer treatment

Nanocarriers have demonstrated great promise in the delivery of hydrophobic drugs particularly to tumor spaces by enhanced permeability and retention (EPR) effects. Mesoporous silica nanoparticles (MSNs) are the attractive nanocarrier system to reduce the drug's toxic side effects, enable controlled drug release, prevent drug degradation and provide a biocompatible and biodegradable high surface area carrier. Surface-modified MSNs have been applied to increase drug loading and efficiency. In this study, functionalized MSNs loaded with methotrexate (MTX) were designed for use as a cytotoxic agent. The MSNs were first modified with 3-triethoxysilylpropylamine (APTES) and then with chitosan through covalent coupling mediated by glutaraldehyde. The physicochemical properties of the nanoparticles were optimized for each step. The loading percentage (12.2%) and release profile of MTX as an anti-breast cancer drug, loaded at amine-modified MSNs, were measured via high performance liquid chromatography (HPLC). Moreover, the uptake profiles of fluorescein isothiocyanate (FITC)-labeled MSN-APTES-chitosan with or without MTX were monitored on MCF7 cancer cells via confocal microscopy. Following exposure of nanoparticles to body fluids, they were surrounded by specific proteins that may affect their cellular uptake. Hence, the adsorption profiles of protein corona on the surface of MSN, amine-modified MSN and MTX-loaded MSN-APTES-chitosan were analyzed. The cytotoxic potential for killing breast cancer cells was also studied. The MTX loaded MSN-APTES-chitosan showed a positive effect at a low dose (0.5 μM MTX). In this study, we introduce a new method to synthesize biodegradable MSNs with small and uniform particle size, achieve high MTX loading via covalent amine and chitosan-functionalization, monitor the cellular uptake and demonstrate the potential to decrease the viability of breast cancer cells at low dose.

Lipid-PLGA hybrid nanoparticles of paclitaxel: Preparation, characterization, in vitro and in vivo evaluation

Paclitaxel loaded lipid-polymer nanoparticles (NPs) were successfully synthesized using poly lactide-co-glycolide (PLGA) as polymer and stearyl amine, soya lecithin as lipids via single step nanoprecipitation method. The study was aimed to combine the advantage of structural integrity of hybrid NPs containing PLGA core and lipid in the shell. Surfactants such as polyvinyl alcohol (PVA), tocopheryl polyethylene glycol succinate (TPGS), pluronic 68 (F68) and human serum albumin (HSA) were used as stabilizers. NPs were characterized w.r.t. morphology, particle size, zeta potential, encapsulation efficiency, in vitro drug release, protein binding capability and blood compatibility. NPs were in size range of 150-400 nm and the particle size was greatly influenced by type and concentration of surfactants and lipids. TEM analysis confirmed the spherical shape and coating of the lipid on the NPs surface. Highest percentage entrapment efficiency was observed in NPs prepared with HSA as surfactant. The release rate of paclitaxel from modified NPs was much slower as compared to unmodified NPs. The percent protein binding of P-PVA, P-TPGS, P-F68 and P-HSA (unmodified NPs) was found to be 15.11%, 16.27%, 27.90% and 33.72%, respectively demonstrating effect of surface properties of NPs on protein binding. The hemolytic activity of the NPs was found to be dependent on type of surfactant and not on the lipid employed. PVA, TPGS, F68, HSA surfactants showed ~16%, ~10%, ~13%, ~7% hemolysis rate, respectively. The surface nature of NPs had a significant effect on the circulation profile of formulations. The HSA based NPs showed prolonged blood circulation time when compared to NPs without lipid coating. Thus, the synthesized dual lipid coated PLGA NPs with HSA could act as a potential nano-system for controlled delivery of paclitaxel.

Enzymatic Modifications of Chitin, Chitosan, and Chitooligosaccharides

Chitin and its N-deacetylated derivative chitosan are two biological polymers that have found numerous applications in recent years, but their further deployment suffers from limitations in obtaining a defined structure of the polymers using traditional conversion methods. The disadvantages of the currently used industrial methods of chitosan manufacturing and the increasing demand for a broad range of novel chitosan oligosaccharides (COS) with a fully defined architecture increase interest in chitin and chitosan-modifying enzymes. Enzymes such as chitinases, chitosanases, chitin deacetylases, and recently discovered lytic polysaccharide monooxygenases had attracted considerable interest in recent years. These proteins are already useful tools toward the biotechnological transformation of chitin into chitosan and chitooligosaccharides, especially when a controlled non-degradative and well-defined process is required. This review describes traditional and novel enzymatic methods of modification of chitin and its derivatives. Recent advances in chitin processing, discovery of increasing number of new, well-characterized enzymes and development of genetic engineering methods result in rapid expansion of the field. Enzymatic modification of chitin and chitosan may soon become competitive to conventional conversion methods.

Formulation approaches for improved retinoids delivery in the treatment of several pathologies

Retinoid acid (RA) and other retinoids are extensively used as therapeutic agents in the treatment of several types of cancer and skin disorders. However, the efficiency of these medical agents is compromised due to the unsatisfactory concentration of retinoids in the target cells/tissues. Furthermore, severe side-effects are related to retinoids administration. Incorporation of retinoids into carrier-based delivery systems using encapsulation technology has been proposed in order to overcome the limitations of using free retinoids in the treatment of several pathologies. The present work starts exploring the competences and the difficulties of using retinoids in health care. The metabolism and the main considerations about the mechanism of action of retinoids are also discussed. The final sections are focused on the most recent studies about RA controlled delivery systems to be used in the medical field.

Protein Adsorption: A Feasible Method for Nanoparticle Functionalization?

Nanomaterials are now well-established components of many sectors of science and technology. Their sizes, structures, and chemical properties allow for the exploration of a vast range of potential applications and novel approaches in basic research. Biomedical applications, such as drug or gene delivery, often require the release of nanoparticles into the bloodstream, which is populated by blood cells and a plethora of small peptides, proteins, sugars, lipids, and complexes of all these molecules. Generally, in biological fluids, a nanoparticle’s surface is covered by different biomolecules, which regulate the interactions of nanoparticles with tissues and, eventually, their fate. The adsorption of molecules onto the nanomaterial is described as “corona” formation. Every blood particulate component can contribute to the creation of the corona, although small proteins represent the majority of the adsorbed chemical moieties. The precise rules of surface-protein adsorption remain unknown, although the surface charge and topography of the nanoparticle seem to discriminate the different coronas. We will describe examples of adsorption of specific biomolecules onto nanoparticles as one of the methods for natural surface functionalization, and highlight advantages and limitations. Our critical review of these topics may help to design appropriate nanomaterials for specific drug delivery.

Nanoparticles based on retinoic acid caped with ferrocenium: a novel synthesized targetable nanoparticle both with anti-cancer effect and drug loading capacity

To date, there is an urgent need for cancer treatment to improve in many ways in order to successfully cure all cancers. Retinoic acid (RA) is a promising anti-cancer drug through influencing cancer stem cells (CSCs). Taxol is a chemotherapy drug for many cancers. To increase the anti-cancer effects of RA and taxol, we created a novel RA nanoparticle, FCRAN, which has the ability of carrying a second anti-cancer drug, taxol, using nanotechnological methods. The results of this study demonstrated that this RA nanoparticle was water-soluble and retained the same effects as RA on cancer cells, such as inhibiting the proliferation of CSCs, inducing the differentiation of CSCs, and enhancing the sensitivity of CSCs to chemotherapeutic drugs. In addition, this RA nanoparticle can be used to carry a second anticancer drug, taxol, to become FCRAN/T and synergistically enhance the anti-cancer effects of both drugs in vivo. Interestingly, the FCRAN/T is a targetable anti-cancer nanoparticle in the presence of higher levels of glutathione (GSH) in cancer cells. Our results demonstrate that our novel synthesized nanoparticles not only retain the RA functions, but can also carry a second anticancer drug to play a synergistic anticancer role with good water solubility, in particular FCRAN/T can target cancer cells. Therefore, our novel synthesized targetable anti-cancer nanoparticles have a better application prospect than that of RA or taxol alone.

A retinoic acid nanoparticle with the ability of carrying a second anti-cancer drug, taxol, was developed. The anti-cancer nanoparticles were shown to have a better application prospect than that of RA or taxol alone.

Synergistic Effect of Retinoic Acid Polymeric Micelles and Prodrug for the Pharmacodynamic Evaluation of Tumor Suppression

All-trans retinoic acid (ATRA) is an effective agent that induces differentiation, inhibits cell proliferation, and acts as an anticancer agent. ATRA was successfully conjugated with Pluronic F127 via esterification to enhance its anticancer effects. Pluronic-ATRA showed high cytotoxicity and inhibitory concentrations (IC₅₀) 50% lower than those of ATRA in various breast cancer cell lines (4T1:31.16–8.57 μg/mL; EMT6: 50.48–7.08 μg/mL; MDA-MB-231:37.58–8.99 μg/mL; BT474:25.27–9.09 μg/mL). In combination with chemotherapy, Pluronic-ATRA synergistically enhanced the cytotoxic effects of cisplatin (CDDP). Pluronic-ATRA combined with CDDP effectively suppressed breast tumor growth in vivo. The results of this study demonstrate the potential of Pluronic-ATRA as an anticancer agent that can be used in combination therapy against solid tumors.

Rising horizon in circumventing multidrug resistance in chemotherapy with nanotechnology

Multidrug resistance (MDR) is one of the key barriers in chemotherapy, leading to the generation of insensitive cancer cells towards administered therapy. Genetic and epigenetic alterations of the cells are the consequences of MDR, resulted in drug resistivity, which reflects in impaired delivery of cytotoxic agents to the cancer site. Nanotechnology-based nanocarriers have shown immense shreds of evidence in overcoming these problems, where these promising tools handle desired dosage load of hydrophobic chemotherapeutics to facilitate designing of safe, controlled and effective delivery to specifically at tumor microenvironment. Therefore, encapsulating drugs within the nano-architecture have shown to enhance solubility, bioavailability, drug targeting, where co-administered P-gp inhibitors have additionally combat against developed MDR. Moreover, recent advancement in the stimuli-sensitive delivery of nanocarriers facilitates a tumor-targeted release of the chemotherapeutics to reduce the associated toxicities of chemotherapeutic agents in normal cells. The present article is focused on MDR development strategies in the cancer cell and different nanocarrier-based approaches in circumventing this hurdle to establish an effective therapy against deadliest cancer disease.

Self-assembled dual-drug loaded core-shell nanoparticles based on metal-free fully alternating polyester for cancer theranostics

Recent research has been directed to the use of biocompatible and biodegradable metal-free fully alternating polyester nanomaterial in drug delivery application. The practice of triethyl borane (Et₃B)/Bis(triphenylphosphoranylidene)ammonium chloride (PPNCl) Lewis pair as non-metallic catalyst was carried out to synthesize alternating copolymer of commercially available tert-butyl glycidyl ether (tBGE) and phthalic anhydride (PA) (poly(tBGE-alt-PA) copolymer) of low M_nvia nearly controlled ring-opening copolymerization (ROCOP) reaction. This biocompatible, hemocompatible, and biodegradable copolymer was used in the fabrication of different nanodrug formulations (NDFs) loaded with doxorubicin (DOX), curcumin (CUR) and their combination. Transmission electron microscope (TEM) imaging showed the spherical shape and core-shell internal structure for all NDFs with an average particle diameter ranging between 200 and 250 nm. X-ray diffraction (XRD) analysis displayed the amorphous nature of both DOX and CUR after their entrapment into the copolymer matrix. Differential scanning colorimetry (DSC) analysis presented no potential chemical interactions between the drug and copolymer. The cellular drug uptake study showed the increased uptake for all NDFs compared to free drug and exhibited higher DOX and CUR accumulation in dual-drug loaded nanoparticles treated pancreatic cancer (MIA PaCa-2) cells. The in vitro drug release kinetic study displayed the slow sustained drug release behavior with anomalous transport for both DOX and CUR in a defined physiological environment. Further, the anti-tumor efficacy of all NDFs was examined on several different cancer cell lines and maximum cytotoxicity was observed in MIA PaCa-2 cells with low inhibitory concentration (IC₅₀) values. These NDFs inhibited the proliferation of MIA PaCa-2 cells due to cell cycle arrest in G2/M phase. In result, MIA PaCa-2 cells underwent apoptosis with significant changes in mitochondrial membrane potential and increased reactive oxygen species (ROS) level. In future, this study will open several novel insights related to the use of such biocompatible and biodegradable metal-free polyesters in targeted drug delivery, tissue engineering and other biomedical applications.

pH and redox dual-responsive copolymer micelles with surface charge reversal for co-delivery of all-trans-retinoic acid and paclitaxel for cancer combination chemotherapy

BACKGROUND

Co-delivery all-trans-retinoic acid (ATRA) and paclitaxel (PTX) is an effective strategy for cancer therapy. However, in many previous reported ATRA conjugated co-delivery systems, the ATRA was released slower than PTX, and the total drug release of ATRA far lower than that of PTX.

PURPOSE

We designed and prepared a pH and redox dual responsive drug delivery system (DA-ss-NPs) co-delivery ATRA and PTX for cancer therapy. The surface charge of DA-ss-NPs could change from negative to positive under tumor slightly acidic microenvironment, and both drugs could be quickly released from DA-ss-NPs under intracellular high concentration of glutathione (GSH).

METHODS

The DA-ss-NPs were constructed by encapsulating PTX into the hydrophobic core of the polymer micelles, in which the polymer was synthesized by conjugating ATRA and 2,3-Dimethylmalefic anhydride (DMA) on side chains of Cystamine dihydrochloride (Cys) modified PEG-b-PAsp (named DA-ss-NPs). The surface charge of DA-ss-NPs under different pH conditions were detected. And the drug release was also measured under different concentration of GSH. The therapeutic effect of DA-ss-NPs were investigated in Human lung cancer A549 cells and A549 tumor-bearing mice.

RESULTS

The zeta potential of DA-ss-NPs was -16.3 mV at pH 7.4, and which changed to 16 mV at pH 6.5. Cell uptake experiment showed that more DA-ss-NPs were internalized by A549 cells at pH 6.5 than that at pH 7.4. In addition, in presence of 10 mM GSH at pH 7.4, about 75%-85% ATRA was released from DA-ss-NPs within 48 h; but less than 20% ATRA was released without GSH. In vivo antitumor efficiency showed that the DA-ss-NPs could affectively inhibite the tumor in compared with control groups.

CONCLUSION

The charge-reversal and GSH-responsive DA-ss-NPs provide an excellent platform for potential tumor therapy.

A novel RGDyC/PEG co-modified PAMAM dendrimer-loaded arsenic trioxide of glioma targeting delivery system

Background

The Traditional Chinese Medicine, arsenic trioxide (ATO, As₂O₃) could inhibit growth and induce apoptosis in a variety of solid tumor cells, but it is severely limited in the treatment of glioma due to its poor BBB penetration and nonspecifcity distribution in vivo.

Purpose

The objective of this study was encapsulating ATO in the modified PAMAM den-drimers to solve the problem that the poor antitumor effect of ATO to glioma, which provide a novel angle for the study of glioma treatment.

Methods

The targeting drug carrier (RGDyC-mPEG-PAMAM) was synthesized based on Arg-Gly-Asp (RGDyC) and αvβ3 integrin targeting ligand, and conjugated to PEGylated fifth generation polyamidoamine dendrimer (mPEG-PAMAM). It was characterized by nuclear magnetic resonance, fourier transform infrared spectra, Nano-particle size-zeta potential analyzer,etc. The in vitro release characteristics were studied by dialysis bag method. MTT assay was used to investigate the cytotoxicity of carriers and the antitumor effect of ATO formulation. In vitro blood-brain barrier (BBB) and C6 cell co-culture models were established to investigate the inhibitory effect of different ATO formulation after transporting across BBB. Pharmacokinetic and antitumor efficacy studies were investigated in an orthotopic murine model of C6 glioma.

Results

The prepared RGDyC-mPEG-PAMAM was characterized for spherical dendrites, comparable size (21.60±6.81 nm), and zeta potential (5.36±0.22 mV). In vitro release showed that more ATO was released from RGDyC-mPEG-PAMAM/ATO (79.5%) at pH 5.5 than that of pH 7.4, during 48 hours. The cytotoxicity of PEG-modified carriers was lower than that of the naked PAMAM on both human brain microvascular endothelial cells and C6 cells. In in vitro BBB model, modification of RGDyC heightened the cytotoxicity of ATO loaded on PAMAM, due to an increased uptake by C6 cells. The results of cell cycle and apoptosis analysis revealed that RGDyC-mPEG-PAMAM/ATO arrested the cell cycle in G2-M and exhibited threefold increase in percentage of apoptosis to that in the PEG-PAMAM/ATO group. Compared with ATO-sol group, both RGDyC-mPEG-PAMAM/ATO and mPEG-PAMAM/ATO groups prolonged the half-life time, increased area under the curve, and improved antitumor effect, significantly. While the tumor volume inhibitory of RGDyC-mPEG-PAMAM/ATO was 61.46±12.26%, it was approximately fourfold higher than the ATO-sol group, and twofold to the mPEG-PAMAM/ATO group.

Conclusion

In this report, RGDyC-mPEG-PAMAM could enhance the antitumor of ATO to glioma, it provides a desirable strategy for targeted therapy of glioma.

A novel mixed polymeric micelle for co-delivery of paclitaxel and retinoic acid and overcoming multidrug resistance: synthesis, characterization, cytotoxicity, and pharmacokinetic evaluation

In the current study, retinoic acid (RA) was conjugated to Pluronic F127 (PF127) through an esterification process. Mixed micelles were formed with tocopheryl polyethylene glycol 1000 (TPGS) for co-delivery of paclitaxel (PTX) and RA to the cancer cells. Mixed micelles of RA-PF127 and TPGS in different weight ratios (10:0, 7:3, 5:5, 3:7, 0:10 w/w) were prepared and physicochemical properties including, particle size, zeta potential, critical micelle concentration (CMC), drug loading content, entrapment efficiency, drug release, cellular uptake and in vitro cytotoxicity, were investigated in details. Furthermore, the pharmacokinetics of PTX-loaded optimized mixed micelles were evaluated in Sprague-Dawley rats and compared with Stragen^® (PTX in Cremophor EL^®). Particle sizes and zeta potentials of the drug-loaded micelles were in the range of 102.6-223.5 nm and -5.3 to -9.6 mV, respectively. The 7:3 and 5:5 micellar combinations had lower CMC values (0.034-0.042 mg/mL) than 0:10 (0.124 mg/mL). The entrapment efficiencies of 10:0, 7:3, and 5:5 were 53.4 ± 9.3%, 61.3 ± 0.5%, and 78.7 ± 1.66%, respectively. The release rates of PTX from 7:3 and 5:5 mixed micelles were significantly slower than other formulations. Cytotoxicity assay demonstrated increased cytotoxic activity of PTX-loaded mixed micelles compared to free PTX. The V_d and t_1/2ß of PTX-loaded RA-PF127/TPGS (7:3) were increased by 2.61- and 1.27-fold, respectively, while the plasma area under the curve (AUC) of the micelles was 2.03-fold lower than those of Stragen^®. Therefore, these novel mixed micelles could be effectively used for delivery of PTX and RA to the cancer cells. Moreover, TPGS as part of micelle composition could enhance the therapeutic effect of PTX and reduce side effects.

Fabrication of all-trans-retinoic acid-loaded biocompatible precirol: A strategy for escaping dose-dependent side effects of doxorubicin

BACKGROUND

Drug delivery-based nanoparticles have been emerged to be an alternative and efficient approach to cancer therapy compared to conventional systems. Here, we investigated the role of all-trans retinoic acid (ATRA) formulated with precirol in increasing doxorubicin (Dox) induced apoptosis and cell cycle arrest in MDA-MB-231 breast cancer cells.

METHODS

ATRA-loaded Nano structured lipid carriers (NLCs) were evaluated in terms of particle size, zeta potential, Fourier transforms infrared spectroscopy (FTIR), cell internalization, and scanning electron microscope (SEM). To understand molecular mechanism of apoptosis and cell cycle progression flow cytometric assay, MTT and DAPI staining was applied. Real time (RT)-PCR analysis was employed to investigate the expression of apoptosis related genes, including Survivin, Bcl-2 and Bax.

RESULTS

The optimized ATRA formulation exhibited average particle size of 95±5nm with nearly narrow size distribution. The IC50 values for ATRA and doxorubicin were 48±0.4μM and 0.81±0.02μM, respectively. ATRA-loaded NLCs decreased percentage of cell proliferation from 51±7.2% to 36±4.1% (p <0.05). Co-treatment of the MDA-MB-231 cells with ATRA formulation and doxorubicin caused two-fold increase in the percentage of apoptosis (p<0.05). The results from gene expression exhibited a significant decrease in survivin along with increase at Bax mRNA levels accompanied by a slight increase in Bax/Bcl-2 ratio.

CONCLUSION

Our results propose that ATRA encapsulated in precirol as a biocompatible compound augments the efficacy of Dox in cancer therapy.

Physicochemical characterization of chitosan-hyaluronan-coated solid lipid nanoparticles for the targeted delivery of paclitaxel: a proof-of-concept study in breast cancer cells

Aim: To investigate the potential of modified solid lipid nanoparticles (SLN) for the delivery of paclitaxel (PAX). Materials & methods: SLN loaded with PAX were prepared via modified high-pressure hot homogenization. Formulation parameters were optimized to obtain a high-quality delivery system. SLN cores were coated, layer-by-layer, with a chitosan and hyaluronan (HA) shell. Selectivity toward HA receptors was tested in a breast cancer cell line, MCF-7. Results: Stable and reproducible nano-sized and negatively charged nanoparticles resulted. Findings reveal that chitosan-HA-coated SLN facilitated the targeting, cellular uptake and the time-/dose-controlled delivery and release of PAX, enhancing intrinsic chemotherapeutic activities. Conclusion: SLN are suitable carrier candidates for nano-oncology given their localized, and potent cytotoxic potential overcoming multidrug-resistant cancer cells.

Characterization of the in vitro effects of gallic acid-grafted-chitooligosaccharides in the suppression of AGS human gastric cancer cell proliferation

G-COS was compared with COS for its influence on the proliferation of AGS human gastric cancer cells, showing an increase in the accumulation of cells in the sub-G1 phase and early apoptosis.

Cabazitaxel-loaded human serum albumin nanoparticles as a therapeutic agent against prostate cancer

Cabazitaxel-loaded human serum albumin nanoparticles (Cbz-NPs) were synthesized to overcome vehicle-related toxicity of current clinical formulation of the drug based on Tween-80 (Cbz-Tween). A salting-out method was used for NP synthesis that avoids the use of chlorinated organic solvent and is simpler compared to the methods based on emulsion-solvent evaporation. Cbz-NPs had a narrow particle size distribution, suitable drug loading content (4.9%), and superior blood biocompatibility based on in vitro hemolysis assay. Blood circulation, tumor uptake, and antitumor activity of Cbz-NPs were assessed in prostatic cancer xenograft-bearing nude mice. Cbz-NPs exhibited prolonged blood circulation and greater accumulation of Cbz in tumors along with reduced toxicity compared to Cbz-Tween. Moreover, hematoxylin and eosin histopathological staining of organs revealed consistent results. The levels of blood urea nitrogen and serum creatinine in drug-treated mice showed that Cbz-NPs were less toxic than Cbz-Tween to the kidneys. In conclusion, Cbz-NPs provide a promising therapeutic for prostate cancer.

Effective method of chitosan-coated alginate nanoparticles for target drug delivery applications

In the present study, alginate nanoparticles were firstly prepared for paclitaxel (PTX) delivery with an average size of 200 ± 21 nm. To improve the stability and targeting effect, the chitosan (CS) and folate-chitosan (FA-CS) were introduced to form PTX-loaded CS/ALG NPs and FA-CS/ALG NPs by a new double emulsion cross-linking electrostatic attraction method. The optimization chitosan concentration was 0.5% obtained from the experiment results. The CS/ALG-PTX NPs and FA-CS/ALG-PTX NPs had the average particle size of 306.9 ± 12.9 nm and 283.6 ± 19.2 nm with the zeta potential of 31.1 ± 1.3 mV and -2.98 ± 0.7 mV, and had higher drug loading and entrapment efficiencies than ALG-PTX NPs. The in vitro drug release profile along with release kinetics and mechanism from PTX-loaded NPs were studied under two simulated physiological conditions. Further, the in vitro anti-cancer activity of nanoparticles and the cellular uptake of nanoparticles on HepG2 cells were investigated. The results demonstrated that alginate, CS/ALG and FA-CS/ALG can be used as nanoformulation drug carriers by our new method, and FA-CS/ALG was a promising vehicle for anticancer drug targeted delivery system.

Single step synthesis of carbon dot embedded chitosan nanoparticles for cell imaging and hydrophobic drug delivery

The florescent carbon dot conjugated chitosan nanoparticles are developed for the cellular imaging and delivery of poorly water soluble drug telmisartan (TEL).