Good Cellular Uptake Research Articles

Original Research Article Novel Nano-Sized Iron Complex Application Using Folate Based Imaging Agent

Design and evaluation of new chemically nano composites towards molecular imaging of malignant tumors is being considered as a kind of medical global research interests. In the current experiment novel nano-composite based on gadolinium ions and anionic linear globular Dendrimer G2 (as biocompatible biodegradable hybrid nanomaterial grafted to folic acid was developed and biophysically assayed. The results showed a very good Magnetic Resonance (MR) relaxivity data on T2 decreasing as well as a very good cellular uptake and tolerance. The complex was found toxic with employing apoptosis as main mechanism of action on cancerous cells respectively. Based on results it could be concluded that such nano-complex may be used as novel theranostic agent in further in vivo practices in near future.

Synthesis of Ibuprofen Conjugated Molecular Transporter Capable of Enhanced Brain Penetration

Based on the strong evidences between inflammation and neurodegeneration, nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, are considered as effective agents to reduce the risk of Alzheimer’s and Parkinson’s disease. However, the clinical use of NSAIDs in these diseases is limited by low brain distribution. In this study, we had synthesized ibuprofen conjugate which has good brain penetration.S-(+)-Ibuprofen was covalently attached to a molecular transporter having FITC and eight terminal guanidine groups. This conjugate showed good cellular uptake property in live cells. It was also injected into a mouse and the distribution of the compound was examined in each organ. The conjugate was well delivered to mouse brain indicating the conjugate is able to cross the blood-brain barrier. Our novel synthetic ibuprofen conjugate will hopefully deliver other NSAIDs into brain and is therefore applicable to the neurodegenerative diseases treatment or prevention.

Gd3+-Asparagine-Anionic Linear Globular Dendrimer Second-Generation G2 Complexes: Novel Nanobiohybrid Theranostics.

Designing a unique theranostic biocompatible, biodegradable, and cost-effective agent which is easy to be synthesized as a biohybrid material was the aim of this study. In this matter, asparagine attached to anionic linear globular dendrimer G2 (as a biocompatible, biodegradable, and cost-effective agent which is negatively charged nanosized and water soluble polymer that outweighs other traditionally used dendrimers) and finally contrast agent (Gd3+) was loaded (which made complexes) in synthesized asparagine-dendrimer. Observations revealed that, in addition to successful colon cancer and brain targeting, Gd3+-dendrimer-asparagine, the proposed theranostic agent, could increase T1 MR relaxation times, decrease T2 MR relaxation times significantly, and improve contrast of image as well as illustrating good cellular uptake based on florescent microscopy/flow cytometry and ICP-mass data. In addition to that, it increased tumor growth inhibition percentage (TGI%) significantly compared to FDA approved contrast agent, Magnevist. Totally, Gd3+-anionic linear globular dendrimer G2-asparagine could be introduced to the cancer imaging/therapy (theranostics) protocols after in vivo MR and fluorescent analysis and passing clinical trials. Hence, this nanotheranostic agent would be a promising candidate for brain drug delivery and imaging in the future.

Bovine Serum Albulmin Protein-Templated Silver Nanocluster (BSA-Ag13 ): An Effective Singlet Oxygen Generator for Photodynamic Cancer Therapy.

This paper reports a novel synthesis approach of bovine serum albumin (BSA) protein-templated ultrasmall (<2 nm) Ag nanocluster (NC) with strong singlet oxygen generation capacity for photodynamic therapy (PDT). An atomically precise BSA-Ag13 NC (i.e., 13 Ag atoms per cluster) is successfully synthesized for the first time by using NaOH-dissolved NaBH4 solution as the controlling reducing agent. The ubiquitous size of BSA-Ag13 NC results in unique behaviors of its photoexcited states as characterized by the ultrafast laser spectroscopy using time-correlated single photon counting and transient absorption techniques. In particular, triply excited states can be largely present in the excited BSA-Ag13 NC and readily sensitized molecular oxygen to produce singlet oxygen (1 O2 ) with a high quantum efficiency (≈1.26 using Rose Bengal as a standard). This value is much higher than its Au analogue (i.e., ≈0.07 for BSA-Au25 NC) and the commonly available photosensitizers. Due to the good cellular uptake and inherent biocompatibility imparted by the surface protein, BSA-Ag13 NC can be applied as an effective PDT agent in generating 1 O2 to kill cancer cell as demonstrated in this study.

Targeted Mesoporous Silica Nanoparticles Delivering Arsenic Trioxide with Environment Sensitive Drug Release for Effective Treatment of Triple Negative Breast Cancer.

In this study, we report a novel modality of using a mesoporous silica nanoparticles (MSNs)-based drug delivery system with RGD peptide as a targeting ligand to load arsenic trioxide (ATO) (ATO-MSNs-RGD) for treating MDA-MB-231 triple-negative breast cancer. The MSNs, ATO-MSNs, and ATO-MSNs-RGD were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and Brunauer-Emmet-Teller (BET) method. The data indicated that the MSNs possessed MCM-41 type mesopores with high surface area of ∼1021 m2/g and pore diameter of ∼2.2 nm. However, both values dramatically decreased after MSNs were encapsulated with ATO or modified with RGD. The amount of surface anchored RGD peptide was determined to be 0.20 mmol/g. Glutathione (GSH) greatly enhanced ATO release from MSNs. Confocal laser microscopy images demonstrated that both ATO-MSNs and ATO-MSNs-RGD had good cellular uptake that improved with longer incubation time and nanoparticle concentration and the ATO-MSNs-RGD showed clearly improved cellular uptake compared with ATO-MSNs. The MSNs, ATO-MSNs, ATO-MSNs-RGD, and ATO were used to treat mice bearing MDA-MB-231 breast tumors every 5 days and the findings suggested that ATO-MSNs-RGD provided superior therapeutic ability over MSNs, ATO-MSNs, and ATO.

Enhancing activity of artesunate against breast cancer cells via induced-apoptosis pathway by loading into lipid carriers

Artesunate-loaded nanostructured lipid carriers (ART-NLCs) were prepared by hot homogenization followed by ultrasonication technique. The optimized ART-NLC demonstrated a particle size of 117.5 ± 6.1 nm, with good stability regarding zeta-potential of −19.47 ± 0.9 mV and drug entrapment efficiency of 92.93 ± 1.47%. ART-NLC showed good cellular uptake in breast cancer cells, which was confirmed by confocal laser scanning microscopy (CLSM) and flow cytometry analysis. The significantly higher in vitro cytotoxicity of ART-NLCs against human breast cancer MCF-7, MDA-MB-231 cells as compared with the free ART was recorded. Hoechst 33342 staining indicated that ART-NLC induced higher apoptosis rates in MCF-7 as well as MDA-MB-231cells than free ART.

Visible light-harvesting tricarbonyl Re(I) complex: synthesis and application in intracellular photodynamic effect and luminescence imaging

Re(I) tricarbonyl rhenium(I) complexes attracted much attention owing to the good cellular uptake ability and rich photophysical properties. However, normally Re(I) complexes show short triplet state lifetime and weak absorption in the visible spectra region, and the absorption wavelength usually is shorter than 450 nm. These features are detrimental to the applications of Re(I) complexes in the areas such as photodynamic therapy (PDT) and luminescence bioimaging. Herein, a novel tricarbonyl rhenium(I) complex Re-1 with strong visible light-absorbing ability (624 nm, e=5.69×104 L/(mol cm)), long-lived triplet excited state (τ T=448.9 μs) and moderate fluorescence quantum yield (Φ F=41.6%) was prepared. The photophysical properties of Re-1 were studied with steady state UV-Vis absorption and luminescence spectroscopies, nanosecond transient absorption spectroscopy, as well as DFT/TDDFT calculations. Re-1 was used for intracellular PDT and luminescence imaging studies. The results indicate that Re-1 shows low dark toxicity, but it is able to kill cancer cells on illumination with 635 nm LED.

Effects of dendritic core-shell glycoarchitectures on primary mesenchymal stem cells and osteoblasts obtained from different human donors.

The biological impact of novel nano-scaled drug delivery vehicles in highly topical therapies of bone diseases have to be investigated in vitro before starting in vivo trials. Highly desired features for these materials are a good cellular uptake, large transport capacity for drugs and a good bio-compatibility. Essentially the latter has to be addressed as first point on the agenda. We present a study on the biological interaction of maltose-modified poly(ethyleneimine) (PEI-Mal) on primary human mesenchymal stem cell, harvested from reaming debris (rdMSC) and osteoblasts obtained from four different male donors. PEI-Mal-nanoparticles with two different molecular weights of the PEI core (5000 g/mol for PEI-5k-Mal-B and 25,000 g/mol for PEI-25k-Mal-B) have been administered to both cell lines. As well dose as incubation-time dependent effects and interactions have been researched for concentrations between 1 μg/ml to 1 mg/ml and periods of 24 h up to 28 days. Studies conducted by different methods of microscopy as light microscopy, fluorescence microscopy, transmission-electron-microscopy and quantitative assays (LDH and DC-protein) indicate as well a good cellular uptake of the nanoparticles as a particle- and concentration-dependent impact on the cellular macro- and micro-structure of the rdMSC samples. In all experiments PEI-5k-Mal-B exhibits a superior biocompatibility compared to PEI-25k-Mal-B. At higher concentrations PEI-25k-Mal-B is toxic and induces a directly observable mitochondrial damage. The alkaline phosphatase assay (ALP), has been conducted to check on the possible influence of nanoparticles on the differentiation capabilities of rdMSC to osteoblasts. In addition the production of mineralized matrix has been shown by von-Kossa stained samples. No influence of the nanoparticles on the ALP per cell has been detected. Additionally, for all experiments, results are strongly influenced by a large donor-to-donor variability of the four different rdMSC samples. To summarize, while featuring a good cellular uptake, PEI-5k-Mal-B induces only minimal adverse effects and features clearly superior biocompatibility compared to the larger PEI-25k-Mal-B.Electronic supplementary materialThe online version of this article (doi:10.1186/s12951-015-0128-y) contains supplementary material, which is available to authorized users.

Utilizing a series of fac-Re(CO)3 core based quinonoid containing complexes for photophysical and cell imaging studies

A series of N∩O bis-chelating bridging quinone ligands (H2L1, H2L2 and H2L3) have been utilized to synthesize four dinuclear fac-Re(CO)3 based neutral complexes (1–4) by their reaction with Re(CO)5(OTf), where the N-donors 4-dimethylaminopyridine (for 1), 3,5-dibromopyridine (for 2) and acetonitrile (for 3 and 4) act as ancillary ligands. The complexes were characterized by FTIR, 1H NMR, ESI-MS and elemental analysis. The structures of complexes 1–3 were analysed by X-ray diffraction methods. Photophysical investigations revealed that all the complexes display strong visible-light absorption with absorption maxima at around 500nm (ε=40000–50000M−1cm−1), whereas in the solid state the complexes display high intensity broad bands in the entire UV–Vis–NIR region. Complexes 1–4 were found to be luminescent in fluid solutions at room temperature. Favorable photophysical properties allowed their utilization as luminescent probes for live-cell imaging using HeLa cells, where complexes 2 and 4 were found to display good cellular uptake with co-localization in lysosomal compartments, which was observed as yellow fluorescence. Complexes 2 and 4 displayed very low cytotoxicity, as suggested by LDH production experiments. The photophysical properties, uptake pathway, localization properties and cytotoxicity of the complexes are discussed in detail.

Development and Evaluation of Artesunate-Loaded Chitosan-Coated Lipid Nanocapsule as a Potential Drug Delivery System Against Breast Cancer.

Artesunate (ART)--a well-known hydrophobic anti-malarial agent was incorporated in a polymer-lipid hybrid nanocolloidal system for anti-cancer therapeutic. The lipid negatively charged nanoemulsion was formulated by modified hot homogenization method then covered with positively charged chitosan via electrostatic interaction to obtain chitosan-coated lipid nanocapsule (ART-CLN). Physical properties of the system were characterized in terms of size, charge, morphology, drug loading capacity, and physical state. In addition, anti-cancer activities were confirmed by conducting MTT assay for ART and ART-CLN on different cancer cell lines. Obtained ART-CLN after coating chitosan revealed positive charge (13.2 ± 0.87 mV), small particle size (160.9 ± 3.5 nm), and spherical shape. High drug entrapment efficiency (95.49 ± 1.13%) and sustained release pattern were observed. Moreover, the good cellular uptake was recorded by flow cytometry as well as confocal image. Finally, ART-CLN exhibited stronger anti-cancer activity than free ART on breast cancer cell lines (MCF-7, MDA-MB-231). These results suggested that by loading ART into lipid core of polymer-lipid hybrid carrier, the activity and physical stability of ART can be significantly increased for cancer chemotherapy.

Fluorescent cadmium telluride quantum dots embedded chitosan nanoparticles: a stable, biocompatible preparation for bio-imaging

Fluorescent cadmium telluride quantum dots (CdTe QDs) are an optically attractive option for bioimaging, but are known to display high cytotoxicity. Nanoparticles synthesized from chitosan, a natural biopolymer of β 1-4 linked glucosamine, display good biocompatibility and cellular uptake. A facile, green synthetic strategy has been developed to embed green fluorescent cadmium telluride quantum dots (CdTe QDs) in biocompatible CNPs to obtain a safer preparation than ‘as is’ QDs. High-resolution transmission electron microscopy showed the crystal lattice corresponding to CdTe QDs embedded in CNPs while thermogravimetry confirmed their polymeric composition. Electrostatic interactions between thiol-capped QDs (4 nm, −57 mV) and CNPs (~300 nm, +38 mV) generated CdTe QDs-embedded CNPs that were stable up to three months. Further, viability of NIH3T3 mouse fibroblast cells in vitro increased in presence of QDs-embedded CNPs as compared to bare QDs. At the highest concentration (10 μg/ml), the former shows 34 and 39% increase in viability at 24 and 48 h, respectively, as compared to the latter. This shows that chitosan nanoparticles do not release the QDs up to 48 h and do not cause extended toxicity. Furthermore, hydrolytic enzymes such as lysozyme and chitinase did not degrade chitosan nanoparticles. Moreover, QDs-embedded CNPs show enhanced internalization in NIH3T3 cells as compared to bare QDs. This method offers ease of synthesis and handling of stable, luminescent, biocompatible CdTe QDs-embedded CNPs with a favorable toxicity profile and better cellular uptake with potential for bioimaging and targeted detection of cellular components.

Blending of Diblock and Triblock Copolypeptide Amphiphiles Yields Cell Penetrating Vesicles with Low Toxicity

We prepared dual hydrophilic triblock copolypeptide vesicles that form both micron and nanometer scale vesicles in aqueous media. The incorporation of terminal homoarginine segments into methionine sulfoxide-based vesicles was found to significantly enhance their cellular uptake compared to a non-ionic control. We also demonstrated that diblock and triblock copolypeptides with similar hydrophobic domains were found to mix well and form vesicle populations with uniform compositions. Blending of amphiphiles in vesicle nanocarriers was found to impart these materials with many advantageous properties, including good cellular uptake while maintaining minimal toxicity, as well as biological responsiveness to promote vesicle disruption and release of encapsulated cargos.

The practicality of mesoporous silica nanoparticles as drug delivery devices and progress toward this goal.

Mesoporous silica nanoparticles (MSNs) have been proposed as drug delivery devices for approximately 15years. The history of in vitro studies has been promising, demonstrating that MSNs have the capability for stimulus-responsive controlled release, good cellular uptake, cell specific targeting, and the ability to carry a variety of cargoes from hydrophobic drug molecules to imaging agents. However, the translation of the in vitro findings to in vivo conditions has been slow. Herein, we review the current state-of-the-art in the use of MSN for systemic drug delivery in vivo and provide critical insight into the future of MSNs as systemic drug delivery devices and directions that should be undertaken to improve their practicality.

Luminescent oligo(ethylene glycol)-functionalized cyclometalated platinum(ii) complexes: cellular characterization and mitochondria-specific localization

A readily tunable series of non-planar oligo(ethylene glycol)-substituted phosphorescent Pt(II) complexes has been investigated as live cell imaging agents; suitable structural modifications can give good cellular uptake, traceable mitochondria-specific localization and potent cytotoxic characteristics towards HeLa cells.

Water-soluble arene ruthenium complexes: From serendipity to catalysis and drug design

Shortly after the discovery of benzene ruthenium dichloride and some controversy about its polymeric or dimeric nature in the 1960s, the hydrolysis of this material in water to give a mixture of benzene ruthenium aqua complexes was discovered. However, it took a long time until this reaction and the hydrolysis of other arene analogs were used as an entry to the synthesis of water-soluble arene ruthenium complexes. These complexes are able to activate molecular hydrogen in aqueous solution and allow the design of arene ruthenium bioconjugates. They can serve as catalysts or catalyst precursors for hydrogenation and transfer hydrogenation reactions in water and they are at present one of the most promising classes of metal complexes to replace cisplatin in future cancer therapy, due to their inherent cytotoxicity and their good cellular uptake, conditioned by well balanced lipophilic and hydrophilic properties.

Photodynamic Agents with Anti-metastatic Activities

A new concept in multifunctional anticancer agents is demonstrated. Tetrakis-(diisopropyl-guanidino) zinc phthalocyanine (Zn-DIGP) exhibits excellent properties as a photodynamic therapy (PDT) agent, as well as potential anti-metastatic activities in vivo. Zn-DIGP exhibits good cellular uptake and low toxicity in the dark (EC50 > 80 μM) and is well tolerated upon its intravenous injection into mice at 8 mg/kg. Upon photoexcitation with red laser light (660 nm), Zn-DIGP exhibits a high quantum yield for singlet oxygen formation (Φ ≈ 0.51) that results in potent phototoxicity to cell cultures (EC50 ≈ 0.16 μM). Zn-DIGP is also capable of inhibiting the formation of tumor colonies in the lungs of C57BL/6 mice injected with B16F10 cells. Zn-DIGP therefore inhibits cancer growth by both light-dependent and light-independent pathways. The anti-metastatic activities of Zn-DIGP possibly result from its ability to interfere with the signaling between chemokine CXCL10 and the G protein-coupled receptor CXCR3. Zn-DIGP is a competitive inhibitor of CXCR3 activation (IC50 = 3.8 μM) and selectively inhibits downstream events such as CXCL10-activated cell migration. Consistent with the presence of feedback regulation between CXCR3 binding and CXCL10 expression, Zn-DIGP causes overexpression of CXCL10. Interestingly, Zn-DIGP binds to CXCR3 without activating the receptor yet is able to cause endocytosis and degradation of this GPCR. To the best of our knowledge, Zn-DIGP is the first PDT agent that can facilitate the photodynamic treatment of primary tumors while simultaneously inhibiting the formation of metastatic tumor colonies by a light-independent mode of action.

Polydopamine-Based Surface Modification for the Development of Peritumorally Activatable Nanoparticles

To create poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs), where a drug-encapsulating NP core is covered with polyethylene glycol (PEG) in a normal condition but exposes a cell-interactive TAT-modified surface in an environment rich in matrix metalloproteinases (MMPs). PLGA NPs were modified with TAT peptide (PLGA-pDA-TAT NPs) or dual-modified with TAT peptide and a conjugate of PEG and MMP-substrate peptide (peritumorally activatable NPs, PANPs) via dopamine polymerization. Cellular uptake of fluorescently labeled NPs was observed with or without a pre-treatment of MMP-2 by confocal microscopy and flow cytometry. NPs loaded with paclitaxel (PTX) were tested against SKOV-3 ovarian cancer cells to evaluate the contribution of surface modification to cellular delivery of PTX. While the size and morphology did not significantly change due to the modification, NPs modified with dopamine polymerization were recognized by their dark color. TAT-containing NPs (PLGA-pDA-TAT NPs and PANPs) showed changes in surface charge, indicative of effective conjugation of TAT peptide on the surface. PLGA-pDA-TAT NPs and MMP-2-pre-treated PANPs showed relatively good cellular uptake compared to PLGA NPs, MMP-2-non-treated PANPs, and NPs with non-cleavable PEG. After 3 h treatment with cells, PTX loaded in cell-interactive NPs showed greater toxicity than non-interactive ones as the former could enter cells during the incubation period. However, due to the initial burst drug release, the difference was not as clear as microscopic observation. PEGylated polymeric NPs that could expose cell-interactive surface in response to MMP-2 were successfully created by dual modification of PLGA NPs using dopamine polymerization.

Non-Invasive Ophthalmic Liposomes for Nucleic Acid Delivery to Posterior Segment of Eye

Nucleic acids like siRNA and pDNA are remarkable for treatment of ophthalmic diseases in posterior segment of eye such as age-related macular degeneration (AMD). However, hydrophilic and high molecule compounds are restricted in intraocular distribution through anterior segment of the eye. In addition, the ocular tissue has a blood-retinal barrier which restricts drug delivery thorough systemic administration. Therefore the invasive intravitreal injection has been generally applied for treatment of retinal diseases. The objective in this study is to prepare nucleic acid-loaded liposomes for effective gene delivery to posterior segment of eye by non-invasive ophthalmic administration such as eye-drops. The pDNA/PEI-complex loaded liposomes were prepared using detergent removal method. The obtained liposomes were lyophilized with optimal amount of a cryoprotectant to avoid changes in physical properties and, followed by adjustment of an appropriate volume and osmotic pressure as ophthalmic solution. The liposomes show high pDNA encapsulation efficiency and good cellular uptake ability in human retinal pigment epithelial cells (ARPE-19 cells). We further demonstrate that the modification of ligand which binds to specific receptor on the RPE cells to the liposomes may improve gene delivery efficacy to the posterior segment of eye by non-invasive ocular instillation.

Sequence Defined Disulfide-Linked Shuttle for Strongly Enhanced Intracellular Protein Delivery

Intracellular protein transduction technology is opening the door for a promising alternative to gene therapy. Techniques have to address all critical steps, like efficient cell uptake, endolysosomal escape, low toxicity, while maintaining full functional activity of the delivered protein. Here, we present the use of a chemically precise, structure defined three-arm cationic oligomer carrier molecule for protein delivery. This carrier of exact and low molecular weight combines good cellular uptake with efficient endosomal escape and low toxicity. The protein cargo is covalently attached by a bioreversible disulfide linkage. Murine 3T3 fibroblasts could be transduced very efficiently with cargo nlsEGFP, which was tagged with a nuclear localization signal. We could show subcellular delivery of the nlsEGFP to the nucleus, confirming cytosolic delivery and expected subsequent subcellular trafficking. Transfection efficiency was concentration-dependent in a directly linear mode and 20-fold higher in comparison with HIV-TAT-nlsEGFP containing a functional TAT transduction domain. Furthermore, β-galactosidase as a model enzyme cargo, modified with the carrier oligomer, was transduced into neuroblastoma cells in enzymatically active form.

15N Magnetic Resonance Hyperpolarization via the Reaction of Parahydrogen with 15N-Propargylcholine

(15)N-Propargylcholine has been synthesized and hydrogenated with para-H(2). Through the application of a field cycling procedure, parahydrogen spin order is transferred to the (15)N resonance. Among the different isomers formed upon hydrogenation of (15)N-propargylcholine, only the nontransposed derivative contributes to the observed N-15 enhanced emission signal. The parahydrogen-induced polarization factor is about 3000. The precise identification of the isomer responsible for the observed (15)N enhancement has been attained through a retro-INEPT ((15)N-(1)H) experiment. T(1) of the hyperpolarized (15)N resonance has been estimated to be ca. 150 s, i.e., similar to that reported for the parent propargylcholine (144 s). Experimental results are accompanied by theoretical calculations that stress the role of scalar coupling constants (J(HN) and J(HH)) and of the field dependence in the formation of the observed (15)N polarized signal. Insights into the good cellular uptake of the compound have been gained.