Synthesis and characterization of pH-dependent glycol chitosan and dextran sulfate nanoparticles for effective brain cancer treatment

A novel drug delivery system for the treatment of brain tumors was formulated by methotrexate (MTX)-loaded polymeric nanoparticles (NPs) based on Glycol chitosan (GCS) and Dextran sulfate (DS). The physicochemical properties of resulting particles were investigated, evidencing the contribution of these nanoparticles for brain targeting. In vitro release of MTX was also evaluated. The GCS-DS nanoparticles have been developed based on the modulation of ratio show promise as a system for controlled delivery of the drug to the brain.     

Methotrexate-Loaded Chitosan- and Glycolchitosan-Based Nanoparticles: A Promising Strategy for the Administration of the Anticancer Drug to Brain Tumors

Brain tumor treatment employing methotrexate (MTX) is limited by the efflux mechanism of Pg-p on the blood–brain barrier. We aimed to investigate MTX-loaded chitosan or glycol chitosan (GCS) nanoparticles (NPs) in the presence and in the absence of a coating layer of Tween 80 for brain delivery of MTX. The effect of a low Tween 80 concentration was evaluated. MTX NPs were formulated following the ionic gelation technique and size and zeta potential measurements were acquired. Transport across MDCKII-MDR1 monolayer and cytotoxicity studies against C6 glioma cell line were also performed. Cell/particles interaction was visualized by confocal microscopy. The particles were shown to be cytotoxic against C6 cells line and able to overcome MDCKII-MDR1 cell barrier. GCS-based NPs were the most cytotoxic NPs. Confocal observations highlighted the internalization of Tween 80-coated fluorescent NPs more than Tween 80-uncoated NPs. The results suggest that even a low concentration of Tween 80 is sufficient for enhancing the transport of MTX from the NPs across MDCKII-MDR1 cells. The nanocarriers represent a promising strategy for the administration of MTX to brain tumors which merits further investigations under in vivo conditions.     

Design of biocompatible chitosan microgels for targeted pH-mediated intracellular release of cancer therapeutics

We report the rational design of a chitosan-based drug delivery system. The chitosan derivative N-[(2-hydroxy-3-trimethylammonium)propyl]chitosan chloride (HTCC) was ionically cross-linked by sodium tripolyphosphate (TPP) to form sub-200-nm microgels that are responsive to pH changes. When these microgels were loaded with methotrexate disodium (MTX), a cytotoxic drug for cancer treatment, and conjugated to the targeting biomolecule apo-transferrin, a protein known to enter cells via receptor-mediated endocytosis, enhanced killing of immortalized HeLa cells was observed. In this intracellular delivery method, the microgel was exposed to low-pH environments that caused the chitosan to swell and release the drug. This rational drug delivery design may be useful in enhancing cancer therapy and reducing side effects.     

Conformationally constrained peptides for drug delivery

Peptides have shown great potential in acting as template for developing versatile carrier platforms in nanomedicine, aimed at selective delivery of drugs to only pathological tissues saving its normal neighbors. Cell‐penetrating peptides (CPPs) are short oligomeric peptides capable of translocating across the cell membrane while simultaneously employing multiple mechanisms of entry. Most CPPs exist as disordered structures in solution and may adopt a helical conformation on interaction with cell membrane, vital to their penetrative capability. Herein, we report a series of cationic helical amphipathic peptides (CHAPs), which are topologically constrained to be helical. The peptides were tested against cervical and breast cancer cells for their cell penetration and drug delivery potential. The cellular uptake of CHAP peptides is independent of temperature and energy availability. The activity of the peptides is biocompatible in bovine serum. CHAPs delivered functional methotrexate (MTX) inside the cell as CHAP‐MTX conjugates. CHAP‐MTX conjugates were more toxic to cancer cells than MTX alone. However, the CHAP‐MTX conjugates were less toxic to HEK‐293 cells compared with the cancer cells suggesting higher affinity towards cancer cells.     

Adjusting the Balance between Effective Loading and Vector Migration of Macrophage Vehicles to Deliver Nanoparticles

The nature of macrophage allows the possibility that this cell type could be used as drug delivery system to track therapeutic drug nanoparticles (NPs) in cancer. However, there is no existing research on the regulation between effective loading of NPs and targeted delivery of macrophages. Here, we investigated the important parameters of intracellular NP quantity and the vector migration rate. Macrophage loading capacity was obtained by comparing the uptake quantity of varisized NPs, and the delivery ability of loaded cells was determined by measuring vector migration rates. We observed a positive correlation between the size of NPs and directed macrophage migration. Our findings suggest that the molecular mechanism of migration vector rate regulation involved increased expression levels of colony-stimulating factor-1 (CSF-1) receptor and integrin induced by 100-nm and 500-nm particles. The ability of macrophages uptake to varisized NPs showed the opposite trend, with the increased vector rate of cell migration influenced by NPs. We are able to demonstrate the important balance between effective macrophage loading and targeted delivery. By adjusting the balance parameters, it will be possible to utilize NPs in macrophage-mediated disease diagnosis and therapy.     

Integrated multi-omics analysis reveals unique signatures of paclitaxel-loaded poly(lactide-co-glycolide) nanoparticles treatment of head and neck cancer cells

The use of poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) as carriers for chemotherapeutic drugs is regarded as an actively targeted nano-therapy for the specific delivery of anti-cancer drugs to target cells. However, the exact mechanism by which PLGA NPs boost anticancer cytotoxicity at the molecular level remains largely unclear. This study employed different molecular approaches to define the response of carcinoma FaDu cells to different types of treatment, specifically: paclitaxel (PTX) alone, drug free PLGA NPs, and PTX-loaded PTX-PLGA NPs. Functional cell assays revealed that PTX-PLGA NPs treated cells had a higher level of apoptosis than PTX alone, whereas the complementary, UHPLC-MS/MS (TIMS-TOF) based multi-omics analyses revealed that PTX-PLGA NPs treatment resulted in increased abundance of proteins associated with tubulin, as well as metabolites such as 5-thymidylic acid, PC(18:1(9Z)/18:1(9Z0), vitamin D, and sphinganine among others. The multi-omics analyses revealed new insights about the molecular mechanisms underlying the action of novel anticancer NP therapies. In particular, PTX-loaded NPs appeared to exacerbate specific changes induced by both PLGA-NPs and PTX as a free drug. Hence, the PTX-PLGA NPs’ molecular mode of action, seen in greater detail, depends on this synergy that ultimately accelerates the apoptotic process, resulting in cancer cell death.     

Development of amphiphilic gamma-PGA-nanoparticle based tumor vaccine: potential of the nanoparticulate cytosolic protein delivery carrier

Nanoscopic therapeutic systems that incorporate biomacromolecules, such as protein and peptides, are emerging as the next generation of nanomedicine aimed at improving the therapeutic efficacy of biomacromolecular drugs. In this study, we report that poly(γ-glutamic acid)-based nanoparticles (γ-PGA NPs) are excellent protein delivery carriers for tumor vaccines that delivered antigenic proteins to antigen-presenting cells and elicited potent immune responses. Importantly, γ-PGA NPs efficiently delivered entrapped antigenic proteins through cytosolic translocation from the endosomes, which is a key process of γ-PGA NP-mediated anti-tumor immune responses. Our findings suggest that the γ-PGA NP system is suitable for the intracellular delivery of protein-based drugs as well as tumor vaccines.     

Detoxifying Antitumoral Drugs via Nanoconjugation: The Case of Gold Nanoparticles and Cisplatin

Nanoparticles (NPs) have emerged as a potential tool to improve cancer treatment. Among the proposed uses in imaging and therapy, their use as a drug delivery scaffold has been extensively highlighted. However, there are still some controversial points which need a deeper understanding before clinical application can occur. Here the use of gold nanoparticles (AuNPs) to detoxify the antitumoral agent cisplatin, linked to a nanoparticle via a pH-sensitive coordination bond for endosomal release, is presented. The NP conjugate design has important effects on pharmacokinetics, conjugate evolution and biodistribution and results in an absence of observed toxicity. Besides, AuNPs present unique opportunities as drug delivery scaffolds due to their size and surface tunability. Here we show that cisplatin-induced toxicity is clearly reduced without affecting the therapeutic benefits in mice models. The NPs not only act as carriers, but also protect the drug from deactivation by plasma proteins until conjugates are internalized in cells and cisplatin is released. Additionally, the possibility to track the drug (Pt) and vehicle (Au) separately as a function of organ and time enables a better understanding of how nanocarriers are processed by the organism.     

Silver and Gold Nanoparticles Exposure to In Vitro Cultured Retina – Studies on Nanoparticle Internalization,Apoptosis, Oxidative Stress,Glial- and Microglial Activity

The complex network of neuronal cells in the retina makes it a potential target of neuronal toxicity – a risk factor for visual loss. With growing use of nanoparticles (NPs) in commercial and medical applications, including ophthalmology, there is a need for reliable models for early prediction of NP toxicity in the eye and retina. Metal NPs, such as gold and silver, gain much of attention in the ophthalmology community due to their potential to cross the barriers of the eye. Here, NP uptake and signs of toxicity were investigated after exposure to 20 and 80 nm Ag- and AuNPs, using an in vitro tissue culture model of the mouse retina. The model offers long-term preservation of retinal cell types, numbers and morphology and is a controlled system for delivery of NPs, using serum-free defined culture medium. AgNO₃-treatment was used as control for toxicity caused by silver ions. These end-points were studied; gross morphological organization, glial activity, microglial activity, level of apoptosis and oxidative stress, which are all well described as signs of insult to neural tissue. TEM analysis demonstrated cellular- and nuclear uptake of all NP types in all neuronal layers of the retina. Htx-eosin staining showed morphological disruption of the normal complex layered retinal structure, vacuole formation and pyknotic cells after exposure to all Ag- and AuNPs. Significantly higher numbers of apoptotic cells as well as an increased number of oxidative stressed cells demonstrated NP-related neuronal toxicity. NPs also caused increased glial staining and microglial cell activation, typical hallmarks of neural tissue insult. This study demonstrates that low concentrations of 20 and 80 nm sized Ag- and AuNPs have adverse effects on the retina, using an organotypic retina culture model. Our results motivate careful assessment of candidate NP, metallic or-non-metallic, to be used in neural systems for therapeutic approaches.     

Methotrexate: studies on cellular metabolism. IV. Effect on the mitochondrial oxidation of cytosolic-reducing equivalents in HeLa cells

The effect of methotrexate (MTX) on the mitochondrial oxidation of cytosolic-reducing equivalents in HeLa cells was studied. MTX inhibited (100 per cent) malate dehydrogenase activity, but no effect was observed on that of GOT. MTX (0.5 mM) inhibited (100 per cent) the activity of reconstituted enzymatic system MDH-GOT, probably as a consequence of inhibition of malate dehydrogenase activity. MTX decreased pyruvate production (54 per cent), demonstrating its inhibitory action on the malate-aspartate shuttle. Blockage of the malate-aspartate shuttle by MTX accounts for the decrease in cellular energetic gain. The results obtained are consistent with the view that in HeLa cells, as well as in other tumour cells, the transport of reducing equivalents from cytoplasmic NADH into the respiratory chain of mitochondria is via the malate-aspartate shuttle.     

Mitochondrial dysfunction,autophagy stimulation and non-apoptotic cell death caused by nitric oxide-inducing Pt-coated Au nanoparticle in human lung carcinoma cells

BackgroundReactive oxygen species (ROS)-mediated cancer therapeutic has been at higher appreciation than those mediated by reactive nitrogen species. Cytotoxic mechanism of a novel nitric oxide (NO) inducing-Pt coated Au nanoparticle (NP) has been comparatively studied with the well-established ROS inducing Pt-based anticancer drug cisplatin in human lung A549 carcinoma cells.MethodsCytotoxicity was evaluated by MTT assay, lactate dehydrogenase (LDH) release, thiobarbituric acid substances (TBARS) and C11-Boron dipyrromethene (BODIPY). ROS (O^2·− and H₂O₂) was measured with dihydroethidium (DHE) and H₂O₂-specific sensor. Nitric oxide (NO) and mitochondrial dysfunction were evaluated respectively by NO-specific probe DAR-1 and JC-1. Autophagy was determined by lysotracker (LTR) and monodansylcadaverine (MDC) applied tandemly whereas apoptosis/necrosis by Hoechst/PI and caspase 3 activity.ResultsIC50 (concentration that inhibited cell viability by 50%) of Pt coated Au NP came to be 0.413 μM whereas IC50 of cisplatin came out to 86.5 μM in A549 cells treated for 24 h meaning NPs toxicity was over 200 times higher than cisplatin. However, no significant stimulation of intracellular ROS was observed at the IC50 of Pt coated Au NPs in A549 cells. However, markers like LDH release, TBARS, BODIPY and ROS were significantly higher due to cisplatin in comparison to Pt coated Au NP.ConclusionsPt coated Au NP caused NO-dependent mitochondrial dysfunction and autophagy. Mode of cell death due to NP was much different from ROS-inducing cisplatin.General significancePt coated Au NP offer promising opportunity in cancer therapeutic and warrants advanced study in vivo models of cancer.     

分枝PEI 修饰的PLGA 纳米粒转染DNA 的研究*

目的:建立基于聚(乳酸-羟基乙酸)纳米粒(PLGA)载DNA的基因转染体系,比较用空白聚(乳酸-羟基乙酸)纳米粒(PLG-A-E)吸附质粒DNA和用分枝PEI修饰后的PLGA纳米粒(PLGA-BPEI)吸附质粒DNA优缺点。方法:用乳化蒸发法制备纳米粒,对纳米粒进行表征研究,包括包封率、Zeta电位、粒径大小、稳定性,用荧光显微镜观察它们对NIH3T3和HEK293细胞的转染效率,用MTT检测对它们细胞的毒性。结果:制备了两种基于PLGA的纳米粒,PLGA-E和PLGA-BPEI粒径大小为200-270nm,zeta电位为0-30mV,在血清和不同的pH值时两者均较稳定,转染效率PLGA-BPEI较PLGA-E高,且释放时间早,但前者较后者对细胞毒性大。结论:这两种基于PLGA纳米粒均能有效转染质粒DNA,它们存在不同的优缺点,应根据不同需要进行选择。     

Computational Modeling of Tumor Response to Drug Release from Vasculature-Bound Nanoparticles

Systemically injected nanoparticle (NPs) targeting tumor vasculature offer a venue for anti-angiogenic therapies as well as cancer detection and imaging. Clinical application has been limited, however, due to the challenge of elucidating the complex interplay of nanotechnology, drug, and tumor parameters. A critical factor representing the likelihood of endothelial adhesion is the NP vascular affinity, a function of vascular receptor expression and NP size and surface-bound ligand density. We propose a theoretical framework to simulate the tumor response to vasculature-bound drug-loaded NPs and examine the interplay between NP distribution and accumulation as a function of NP vascular affinity, size, and drug loading and release characteristics. The results show that uniform spatial distribution coupled with high vascular affinity is achievable for smaller NPs but not for larger sizes. Consequently, small (100 nm) NPs with high vascular affinity are predicted to be more effective than larger (1000 nm) NPs with similar affinity, even though small NPs have lower drug loading and local drug release compared to the larger NPs. Medium vascular affinity coupled with medium or larger sized NPs is also effective due to a more uniform distribution with higher drug loading and release. Low vascular affinity hampered treatment efficacy regardless of NP size, with larger NPs additionally impeded by heterogeneous distribution and drug release. The results further show that increased drug diffusivity mainly benefits heterogeneously distributed NPs, and would negatively affect efficacy otherwise due to increased wash-out. This model system enables evaluation of efficacy for vascular-targeted drug-loaded NPs as a function of critical NP, drug, and tumor parameters.     

Paclitaxel-loaded poly(gamma-glutamic acid)-poly(lactide) nanoparticles as a targeted drug delivery system against cultured HepG2 cells

The study was to develop paclitaxel-loaded formulations using a novel type of self-assembled nanoparticles that was composed of block copolymers synthesized from poly(gamma-glutamic acid) and poly(lactide) via a simple coupling reaction. The nanoparticles (the NPs) were prepared with various feed weight ratios of paclitaxel to block copolymer (the P/BC ratio). The morphology of all prepared nanoparticles was spherical and the surfaces were smooth. Increasing the P/BC ratio significantly increased the drug loading content of the prepared nanoparticles, but remarkably reduced the drug loading efficiency. The release rate of paclitaxel from the NPs decreased significantly as the P/BC ratio increased. For the potential of targeting liver cancer cells, galactosamine was further conjugated on the prepared nanoparticles (the Gal-NPs) as a targeting moiety. It was found that the activity in inhibiting the growth of HepG2 cells (a liver cancer cell line) by the Gal-NPs was comparable to that of a clinically available paclitaxel formulation, while the NPs displayed a significantly less activity. This may be attributed to the fact that the Gal-NPs had a specific interaction with HepG2 cells via ligand-receptor recognition. Cells treated with distinct paclitaxel formulations resulted in arrest in the G2/M phase. The arrest of cells in the G2/M phase was highly suggestive of interference by paclitaxel with spindle formation and was consistent with the morphological findings presented herein. In conclusion, the active targeting nature of the Gal-NPs prepared in the study may be used as a potential drug delivery system for the targeted delivery to liver cancers.     

A health concern regarding the protein corona,aggregation and disaggregation

Nanoparticle (NP)–protein complexes exhibit the “correct identity” of NP in biological media. Therefore, protein–NP interactions should be closely explored to understand and modulate the nature of NPs in medical implementations. This review focuses mainly on the physicochemical parameters such as dimension, surface chemistry, morphology of NPs, and influence of pH on the formation of protein corona and conformational changes of adsorbed proteins by different kinds of techniques. Also, the impact of protein corona on the colloidal stability of NPs is discussed. Uncontrolled protein attachment on NPs may bring unwanted impacts such as protein denaturation and aggregation. In contrast, controlled protein adsorption by optimal concentration, size, pH, and surface modification of NPs may result in potential implementation of NPs as therapeutic agents especially for disaggregation of amyloid fibrils. Also, the effect of NPs-protein corona on reducing the cytotoxicity and clinical implications such as drug delivery, cancer therapy, imaging and diagnosis will be discussed. Validated correlative physicochemical parameters for NP–protein corona formation frequently derived from protein corona fingerprints of NPs which are more valid than the parameters obtained only on the base of NP features. This review may provide useful information regarding the potency as well as the adverse effects of NPs to predict their behavior in vivo.     

ANTICANCER MEDICINES (DOXORUBICIN AND METHOTREXATE) CONJUGATED WITH MAGNETIC NANOPARTICLES FOR TARGETING DRUG DELIVERY THROUGH IRON

The uptake of iron is increased by cancer cells. Iron magnetic nanoparticles (MNP) can be used as a nanovehicle for immobilization of anticancer medicines and to integrate them at a target site. The anticancer medicines doxorubicin (DOX) and methotrexate (MTX) were immobilized separately and in combination onto MNP by a glutaraldehyde activation method and confirmed by magnetic nanoparticles linked immunosorbent assay (MagLISA) and Fourier-transform infrared (FTIR) spectroscopy. The phenol peaks of DOX and MTX at 2896.6 cm^?1 to 2912.5 cm^?1 in FTIR spectra of immobilized medicines indicated the conjugation. Affinity-purified anti-DOX and anti-MTX antibodies were used to evaluate the coupling of DOX and MTX onto MNP, and the binding was found 34.6% to 37.2% and 51.8% to 54.3% separately, respectively. The immobilization of DOX and MTX in combination onto MNP was 18% and 27%, respectively. HeLa and B cells were cultured with DOX-MNP, MTX-MNP, and DOX-MNP-MTX separately, and MagLISA indicated that the binding of DOX-MNP/MTX-MNP was 41.5% to 45% with HeLa cells and 20% to 26% with B cells. No significant difference was observed in binding of DOX-MNP-MTX with HeLa and B cells. Results also indicated that the release of medicines at pH 5.0 is more (39% to 44%) than at pH 7.4 (3.7% to 10.2%). Sixteen to 22% more killing effect was observed on HeLa cells than on B cells. In immunohistochemical staining, more deposition of brown color on HeLa cells than on B cells may be due to more expression of iron-binding sites on cancer cells. The dual property of MNP can be used for binding of medicines and for targeting drug delivery.     

Gefitinib loaded PLGA and chitosan coated PLGA nanoparticles with magnified cytotoxicity against A549 lung cancer cell lines

In the current study, gefitinib loaded PLGA nanoparticles (GFT-PLGA-NPs) and chitosan coated PLGA nanoparticles (GFT-CS-PLGA-NPs) were synthesized to investigate the role of surface charge of NPs for developing drug delivery system for non-small-cell lung cancer (NSCLC). The developed NPs were evaluated for their size, PDI, zeta potential (ZP), drug entrapment, drug loading, DSC, FTIR, XRD, in vitro release profile, and morphology. The anti-cancer activity of GFT loaded PLGA NPs and GFT loaded CS-PLGA-NPs were examined in human A549 lung cancer cell lines. In vitro release studies of GFT-CS-PLGA-NPs showed more sustained release in comparison to GFT-PLGA-NPs due surface charge attraction of chitosan. In addition, viability of A549 cells decreases significantly with the increasing concentration of GFT-PLGA NPs and GFT-CS-PLGA-NPs when compared to that of pure GFT and blank PLGA NPs. In addition, the microscopic analysis and counting of viable cells also validate the cytotoxicity of the developed NPs. This investigation proved that the developed NPs would be efficient carriers to deliver GFT with improved efficacy against NSCLC.     

Design considerations for PAMAM dendrimer therapeutics

We have previously shown that methotrexate (MTX) conjugated to a cancer-specific poly amido amine (PAMAM) dendrimer has a higher therapeutic index than MTX alone. Unfortunately, these therapeutics have been difficult to advance because of the complicated syntheses and an incomplete understanding of the dendrimer properties. We wished to address these obstacles by using copper-free click chemistry to functionalize the dendrimer scaffolds and to exploring the effects of two dendrimer properties (the targeting ligand and drug linkage) on cytotoxicity. We conjugated either ester or amide-linker modified MTX to dendrimer scaffolds with or without folic acid (FA). Because of multivalency, the FA and MTX functionalized dendrimers had similar capacities to target the folate receptor on cancer cells. Additionally, we found that the ester- and amide-linker modified MTX compounds had similar cytotoxicity but the dendrimer–ester MTX conjugates were much more cytotoxic than the dendrimer–amide MTX conjugates. These results clarify the impact of these properties on therapeutic efficacy and will allow us to design more effective polymer therapeutics.     

Albumin-based drug delivery as novel therapeutic approach for rheumatoid arthritis

We reported recently that albumin is a suitable drug carrier for targeted delivery of methotrexate (MTX) to tumors. Due to pathophysiological conditions in neoplastic tissue, high amounts of albumin accumulate in tumors and are metabolized by malignant cells. MTX, covalently coupled to human serum albumin (MTX-HSA) for cancer treatment, is currently being evaluated in phase II clinical trials. Because synovium of patients with rheumatoid arthritis (RA) shares various features observed also in tumors, albumin-based drug targeting of inflamed joints might be an attractive therapeutic approach. Therefore, the pharmacokinetics of albumin and MTX in a mouse model of arthritis was examined. Additionally, uptake of albumin by synovial fibroblasts of RA patients and the efficacy of MTX and MTX-HSA in arthritic mice were studied. The results show that when compared with MTX, significantly higher amounts of albumin accumulate in inflamed paws, and significantly lower amounts of albumin are found in the liver and the kidneys. The protein is metabolized by human synovial fibroblasts in vitro and in vivo. MTX-HSA was significantly more effective in suppression of the onset of arthritis in mice than was MTX. In conclusion, albumin appears to be a suitable drug carrier in RA, most likely due to effects on synovial fibroblasts, which might increase therapeutic efficacy and reduce side effects of MTX.