ABSTRACT
To investigate the renal protective effects of the polysaccharide LEP-1a and derivatives of selenium (SeLEP-1a) from Lachnum YM38, cisplatin (CP) was used to establish an acute kidney model. LEP-1a and SeLEP-1a could effectively reverse the decrease in renal index and improved renal oxidative stress. LEP-1a and SeLEP-1a significantly reduced the contents of the inflammatory cytokines. They could inhibit the release of cyclooxygenase 2 (COX-2) and nitric oxide synthase (iNOS) and increase the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and hemeoxygenase-1 (HO-1). At the same time, the PCR results indicated that SeLEP-1a could significantly inhibit the mRNA expression levels of toll-like receptor 4 (TLR4), nuclear factor-kB (NF-κB) p65 and inhibitor of kappa B-alpha (IκBα). Western blot analysis showed that LEP-1a and SeLEP-1a significantly downregulated the expression levels of Bcl-2-associated X protein (Bax) and cleaved caspase-3 and upregulated phosphatidylinositol 3-kinase (p-PI3K), protein kinase B (p-Akt) and B-cell lymphoma 2 (Bcl-2) protein expression levels in the kidney. LEP-1a and SeLEP-1a could improve CP-induced acute kidney injury by regulating the oxidative stress response, NF-κB-mediated inflammation and the PI3K/Akt-mediated apoptosis signalling pathway.
Subject(s)
Acute Kidney Injury , Polysaccharides , Selenium , Animals , Mice , Acute Kidney Injury/chemically induced , Acute Kidney Injury/drug therapy , Acute Kidney Injury/prevention & control , Cisplatin/pharmacology , Cisplatin/toxicity , Kidney/metabolism , NF-E2-Related Factor 2/metabolism , NF-kappa B/metabolism , Oxidative Stress , Phosphatidylinositol 3-Kinases/metabolism , Polysaccharides/pharmacology , Polysaccharides/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Selenium/pharmacology , Organosilicon Compounds/metabolism , Organosilicon Compounds/pharmacologyABSTRACT
Recently the vaginal route consider as an ideal route for drug delivery systems (DDS) administration. This is because, it is suitable for lower drug dosage, higher drug concentration in the genital tract tissues and lower drug concentration in pregnant women blood circulation. However, the vaginal route administration faces many challenges due to the physiology as well as the complexity of vaginal tissue histology. Here in this study, during diestrus stage (optimal condition for foreign substance internalization), single or dual size of fluorescent thiol-organosilica nanoparticles (tOS-NPs) were administrated intravaginally. The biodistribution and reactivity of tOS-NPs in different tissues of the female genital tract were investigated under the fluorescence microscope. Furthermore, using immunohistochemical staining, the expression of F4/80 protein and the role of macrophages in transport and re-location of tOS-NPs from vaginal lumen into different genital tissues or other organs were investigated. This study showed that, tOS-NPs size and type of tissue are important in biodistribution and uptake of tOS-NPs in the genital tract. Small size (100 nm) of tOS-NPs was highly accumulated in the genital tract tissues especially endometrial epithelium compared with large tOS-NPs (1000 nm). Contradictory, the large size induced the expression of F4/80 protein and the number of vaginal macrophages compared with small size. However, both small and large sizes of tOS-NPs were found co-localized with F4/80+ macrophages, located in the vaginal, endometrial and ovarian tissues. The tOS-NPs intravaginally administrated were found in the splenic tissues, indicating its ability to enter the blood circulation from the vaginal lumen. Additionally, the high accumulation of tOS-NPs in the endometrial epithelium indicated the endometrial first pass effect of tOS-NPs. As a result, high concentration of tOS-NPs in the endometrial epithelium may reduce the concentration of tOS-NPs-based DDS in the blood circulation and their side effects. Furthermore, during vaginal tissue optimal condition (diestrus stage), understanding the fate and biodistribution of tOS-NPs will introduce important data about the development of save and effective DDS for the pregnant women.
Subject(s)
Fluorescent Dyes/metabolism , Membrane Glycoproteins/genetics , Nanoparticles/metabolism , Organosilicon Compounds/metabolism , Sulfhydryl Compounds/metabolism , Administration, Intravaginal , Animals , Female , Fluorescent Dyes/administration & dosage , Genitalia, Female , Membrane Glycoproteins/chemistry , Membrane Glycoproteins/metabolism , Mice , Nanoparticles/administration & dosage , Organosilicon Compounds/administration & dosage , Particle Size , Sulfhydryl Compounds/administration & dosage , Tissue DistributionABSTRACT
Cancer has become an important public problem in worldwide since cancer incidence and mortality are growing rapidly. In this study, water soluble and non-aggregated silicon (IV) phthalocyanines and naphthalocyanines containing (3,5-bis{3-[3-(diethylamino)phenoxy]propoxy}phenyl)methoxy groups have been synthesized and characterized to investigate their anticancer potential. Their DNA binding/nuclease, topoisomerases inhibition were investigated using UV-Vis absorption, thermal denaturation and agarose gel electrophoresis. The in vitro cytotoxic properties of the compounds on human lung (A549), breast (BT-20), liver (SNU-398), prostate (DU-145), melanoma (SK-Mel 128) carcinoma and human fibroblast (HFC) normal cell lines were evaluated by using MTT assay. In order to determine the mechanism of cancer cell growth suppression, cell cycle analysis was carried out using flow cytometer on A549 cell line. The Kb values of SiPc1a and SiNc2a were 6.85 ± (0.35) × 106 and 1.72 ± (0.16) × 104 M-1 and Tm values of ct-DNA were calculated as 82.02 °C and 78.07 °C, respectively in the presence of both compounds. The ΔTm values of SiPc1a and SiNc2a were calculated as 6.45 and 2.50 °C, respectively. The nuclease effects of SiPc1a and SiNc2a with supercoiled plasmid pBR322 DNA demonstrated that both compounds did not trigger any DNA nuclease effects at the lowest concentrations without irradiation whereas both compounds in the presence of activating agent (H2O2) showed significant plasmid DNA nuclease actions under irradiation (22.5 J/cm2). SiPc1a and SiNc2a inhibited to topoisomerase I on increasing concentrations whilst they had lower inhibition action toward topoisomerase II that of topoisomerase I. The in vitro cytotoxicity studies displayed that SiPc1a had the highest cytotoxic effects among the tested compounds against A549, SNU-398, SK-MEL128, DU-145, BT-20 and HFC cell lines with CC50 values ranged from 0.49 to 2.99 µM. Furthermore, SiPc1a inhibited cell proliferation by cell cycle arrest in G0/G1 phase. All of these results suggested that SiPc1a is a promising candidate as an anticancer agent.
Subject(s)
Antineoplastic Agents/chemical synthesis , Drug Design , Indoles/chemistry , Organosilicon Compounds/chemistry , Topoisomerase I Inhibitors/chemistry , Antineoplastic Agents/metabolism , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , DNA/chemistry , DNA/metabolism , DNA Topoisomerases, Type I/chemistry , DNA Topoisomerases, Type I/metabolism , DNA Topoisomerases, Type II/chemistry , DNA Topoisomerases, Type II/metabolism , Deoxyribonucleases/antagonists & inhibitors , Deoxyribonucleases/metabolism , G1 Phase Cell Cycle Checkpoints/drug effects , Humans , Hydrogen Peroxide/pharmacology , Indoles/metabolism , Indoles/pharmacology , Organosilicon Compounds/metabolism , Organosilicon Compounds/pharmacology , Solubility , Topoisomerase I Inhibitors/metabolism , Topoisomerase I Inhibitors/pharmacology , Water/chemistryABSTRACT
The outcome of radiotherapy is significantly restricted by tumor hypoxia. To overcome this obstacle, one prevalent solution is to increase intratumoral oxygen supply. However, its effectiveness is often limited by the high metabolic demand for O2 by cancer cells. Herein, we develop a hybrid semiconducting organosilica-based O2 nanoeconomizer pHPFON-NO/O2 to combat tumor hypoxia. Our solution is twofold: first, the pHPFON-NO/O2 interacts with the acidic tumor microenvironment to release NO for endogenous O2 conservation; second, it releases O2 in response to mild photothermal effect to enable exogenous O2 infusion. Additionally, the photothermal effect can be increased to eradicate tumor residues with radioresistant properties due to other factors. This "reducing expenditure of O2 and broadening sources" strategy significantly alleviates tumor hypoxia in multiple ways, greatly enhances the efficacy of radiotherapy both in vitro and in vivo, and demonstrates the synergy between on-demand temperature-controlled photothermal and oxygen-elevated radiotherapy for complete tumor response.
Subject(s)
Nitric Oxide/metabolism , Organosilicon Compounds/metabolism , Oxygen/metabolism , Photochemotherapy/methods , Photosensitizing Agents/metabolism , Quantum Dots/metabolism , Cell Line, Tumor , Humans , Organosilicon Compounds/chemistry , Photosensitizing Agents/therapeutic use , Quantum Dots/chemistry , Quantum Dots/therapeutic use , Radiotherapy/adverse effects , Tumor Hypoxia/drug effects , Tumor Hypoxia/radiation effects , Tumor Microenvironment/drug effects , Tumor Microenvironment/radiation effectsABSTRACT
Treatment of hyperinsulinemic hypoglycemia is challenging. Surgical treatment of insulinomas and focal lesions in congenital hyperinsulinism is invasive and carries major risks of morbidity. Medication to treat nesidioblastosis and diffuse congenital hyperinsulinism has varying efficacy and causes significant side effects. Here, we describe a novel method for therapy of hyperinsulinemic hyperglycemia, highly selectively killing ß-cells by receptor-targeted photodynamic therapy (rtPDT) with exendin-4-IRDye700DX, targeting the glucagon-like peptide 1 receptor (GLP-1R). Methods: A competitive binding assay was performed using Chinese hamster lung (CHL) cells transfected with the GLP-1R. The efficacy and specificity of rtPDT with exendin-4-IRDye700DX were examined in vitro in cells with different levels of GLP-1R expression. Tracer biodistribution was determined in BALB/c nude mice bearing subcutaneous CHL-GLP-1R xenografts. Induction of cellular damage and the effect on tumor growth were analyzed to determine treatment efficacy. Results: Exendin-4-IRDye700DX has a high affinity for the GLP-1R, with a half-maximal inhibitory concentration of 6.3 nM. rtPDT caused significant specific phototoxicity in GLP-1R-positive cells (2.3% ± 0.8% and 2.7% ± 0.3% remaining cell viability in CHL-GLP-1R and INS-1 cells, respectively). The tracer accumulates dose-dependently in GLP-1R-positive tumors. In vivo, rtPDT induces cellular damage in tumors, shown by strong expression of cleaved caspase-3, and leads to a prolonged median survival of the mice (36.5 vs. 22.5 d, respectively; P < 0.05). Conclusion: These data show in vitro as well as in vivo evidence of the potency of rtPDT using exendin-4-IRDye700DX. This approach might in the future provide a new, minimally invasive, highly specific treatment method for hyperinsulinemic hypoglycemia.
Subject(s)
Congenital Hyperinsulinism/drug therapy , Glucagon-Like Peptide-1 Receptor/metabolism , Photochemotherapy/methods , Animals , Cell Line, Tumor , Cricetinae , Cricetulus , Exenatide/metabolism , Exenatide/therapeutic use , Female , Humans , Indoles/metabolism , Indoles/therapeutic use , Mice , Mice, Inbred BALB C , Nesidioblastosis/drug therapy , Organosilicon Compounds/metabolism , Organosilicon Compounds/therapeutic use , RatsABSTRACT
Silicones have many applications and are produced in large quantities. Despite their potential toxicity, information on their environmental mineralisation is scarce. Therefore, we investigated a group of five organosilicon compounds (o-MeOC6H4SiMe3 (1), p-MeOC6H4SiMe3 (2), (p-MeOC6H4)2SiMe2 (3), o-Me2NC6H4SiMe3 (4) and p-Me2NC6H4SiMe3 (5)), recently developed to be 'benign by design' based on their readily degradable core structure. Five different degradability tests were performed, one assessing hydrolytic and two analysing biological and photolytic stability, respectively. All substances, except (p-MeOC6H4)2SiMe2 (3), hydrolysed within 24 h to 50% indicating that this is one of the major pathways of their primary elimination. In agreement with previous research, none of the substances was readily biodegradable. In contrast, 100% of p-Me2NC6H4SiMe3 (5) was primarily eliminated by photolytic and hydrolytic processes. The elimination rates of the other substances ranged from 7% to 64%. Irradiation at shorter wavelengths increased both the extent and speed of photodegradation. Eleven transformation products of p-Me2NC6H4SiMe3 (5) were detected, all of which were completely eliminated within 64 min of irradiation with a Hg lamp (200-400 nm). The insertion of an electron-donating group on the benzene ring like in p-Me2NC6H4SiMe3 (5) clearly enhanced photolytic degradability but further research is necessary to achieve truly biodegradable silicones.
Subject(s)
Environmental Pollutants , Organosilicon Compounds , Aerobiosis , Biodegradation, Environmental , Environmental Pollutants/chemistry , Environmental Pollutants/metabolism , Environmental Pollutants/radiation effects , Hydrogen-Ion Concentration , Hydrolysis , Light , Molecular Structure , Organosilicon Compounds/chemistry , Organosilicon Compounds/metabolism , Organosilicon Compounds/radiation effects , PhotolysisABSTRACT
Biodegradable periodic mesoporous organosilica (BPMO) nanoparticles have emerged as a promising type of nanocarrier for drug delivery, given the biodegradable feature is advantageous for clinical translation. In this paper, we report synthesis and characterization of daunorubicin (DNR) loaded BPMO. DNR was loaded onto rhodamine B-labeled BPMO that contain tetrasulfide bonds. Tumor spheroids and chicken egg tumor models were used to characterize the activity in biological settings. In the first experiment we examined the uptake of BPMO into tumor spheroids prepared from ovarian cancer cells. BPMO were efficiently taken up into tumor spheroids and inhibited their growth. In the chicken egg tumor model, intravenous injection of DNR-loaded BPMO led to the elimination of ovarian tumor. Lack of adverse effect on organs such as lung appears to be due to excellent tumor accumulation of BPMO. Thus, DNR-loaded BPMO represents a promising nanodrug compared with free DNR currently used in cancer therapy. OK.
Subject(s)
Antibiotics, Antineoplastic/pharmacology , Daunorubicin/pharmacology , Nanoparticles/chemistry , Organosilicon Compounds/pharmacology , Ovarian Neoplasms/drug therapy , Animals , Antibiotics, Antineoplastic/chemistry , Cell Proliferation/drug effects , Chickens , Daunorubicin/chemistry , Drug Carriers/chemistry , Drug Carriers/metabolism , Drug Carriers/pharmacology , Drug Delivery Systems , Female , Humans , Nanoparticles/metabolism , Neoplasms, Experimental/drug therapy , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Organosilicon Compounds/chemistry , Organosilicon Compounds/metabolism , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/pathology , Particle Size , Porosity , Surface Properties , Tumor Cells, CulturedABSTRACT
Recently, block copolymer micelles have attracted widespread attention due to their controlled biodegradability and excellent loading capability. Unfortunately, the poor in vivo stability and low delivery efficiency of drug-loaded micelles greatly hampered their biomedical applications. Herein, we develop a new kind of biodegradable magnetite/doxorubicin (Fe3O4/DOX) co-loaded PEGylated organosilica micelles (designated as FDPOMs) with both high circulating stability and smart GSH-triggered biodegradability for magnetically targeted magnetic resonance imaging (MRI) and tumor chemotherapy. The FDPOMs are prepared by the self-assembly of biodegradable polycaprolactone-block-poly(glutamic acid) (PCL-b-PGA), a chemotherapeutic DOX drug and Fe3O4 nanoparticles in an oil/water system, subsequent organosilica cross-linking with 3-mercaptopropyltrimethoxysilane (MPTMS) molecules and surface PEGylation. The resultant FDPOMs exhibit excellent dispersity and stability in biological media, remarkable T2-weighted MR imaging capability, unique GSH-responsive release behavior and selective toxicity to tumor cells. The in vivo experiments show that the FDPOMs not only have improved MR tumor imaging capability, but also exhibit high anti-tumor efficacy due to the strong magnetic targeting ability under an external magnetic field. Consequently, the FDPOMs are promising candidates for magnetically targeted MR imaging and imaging-guided tumor chemotherapy.
Subject(s)
Doxorubicin/pharmacology , Glutathione/metabolism , Magnetic Resonance Imaging/methods , Magnetite Nanoparticles/chemistry , Micelles , Organosilicon Compounds/chemistry , Organosilicon Compounds/metabolism , Animals , Cell Line, Tumor , Doxorubicin/chemistry , Drug Carriers/chemistry , Drug Carriers/metabolism , Drug Liberation , Humans , Hydrophobic and Hydrophilic Interactions , Male , Mice , NIH 3T3 Cells , Polyesters/chemistry , Polyglutamic Acid/chemistry , SafetyABSTRACT
Zwitterionic complexes in aqueous solutions have been extensively explored as the most promising candidate in drug delivery systems for targeted cancer chemotherapy. A POSS-based supramolecular AD-POSS-(sulfobetaine)7/CD-PLLA zwitterionic complex has been fabricated via a combination of efficient click chemistry and host-guest interaction. The well-defined POSS-based zwitterionic polymer could self-assemble into spherical nanoparticles that encapsulated a model cancer drug (DOX) and exhibited drug release in a controlled manner in a faintly acidic environment. On account of the hydrophilic block with cationic and anionic groups in the microscopic range that can form a hydration layer via electrostatic interactions, these drug-loaded nanoparticles exhibited excellent stability in a tumor intracellular microenvironment or under other pH conditions as revealed by dynamic light scattering (DLS) and zeta potential measurements. In vitro experiments demonstrated that these POSS-based nanoparticles had high resistance to non-specific protein absorption and low cytotoxicity against normal cells. Moreover, these DOX-loaded aggregates could be accumulated and effectively internalized by HeLa and MCF-7 tumor cells, exhibiting effective cellular proliferation inhibition via the release of anticancer agents. Therefore, these POSS-based supramolecular amphiphilic zwitterionic complexes, relying on the simple supramolecular interaction and efficient click reaction, could further emerge as a potential universal anticancer drug nanocarrier system for multifunctional cancer chemotherapy.
Subject(s)
Drug Carriers/chemistry , Hydrophobic and Hydrophilic Interactions , Organosilicon Compounds/chemistry , 3T3 Cells , Absorption, Physicochemical , Animals , Biological Transport , Cattle , Cell Proliferation/drug effects , Doxorubicin/chemistry , Drug Carriers/metabolism , Drug Carriers/toxicity , Drug Liberation , Humans , Hydrogen-Ion Concentration , MCF-7 Cells , Materials Testing , Mice , Nanoparticles/chemistry , Organosilicon Compounds/metabolism , Organosilicon Compounds/toxicity , Polyesters/chemistry , Serum Albumin, Bovine/chemistryABSTRACT
Cannabinoids are emerging as promising antitumor drugs. However, complete tumor eradication solely by cannabinoid therapy remains challenging. In this study, we developed a far-red light activatable cannabinoid prodrug, which allows for tumor-specific and combinatory cannabinoid and photodynamic therapy. This prodrug consists of a phthalocyanine photosensitizer (PS), reactive oxygen species (ROS)-sensitive linker, and cannabinoid. It targets the type-2 cannabinoid receptor (CB2R) overexpressed in various types of cancers. Upon the 690-nm light irradiation, the PS produces cytotoxic ROS, which simultaneously cleaves the ROS-sensitive linker and subsequently releases the cannabinoid drug. We found that this unique multifunctional prodrug design offered dramatically improved therapeutic efficacy, and therefore provided a new strategy for targeted, controlled, and effective antitumor cannabinoid therapy.
Subject(s)
Cannabinoids , Photochemotherapy/methods , Prodrugs , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Cannabinoids/chemistry , Cannabinoids/pharmacology , Cell Line, Tumor , Cell Survival/drug effects , HEK293 Cells , Humans , Indoles/chemistry , Indoles/metabolism , Isoindoles , Mice , Organosilicon Compounds/chemistry , Organosilicon Compounds/metabolism , Photosensitizing Agents/chemistry , Photosensitizing Agents/pharmacology , Prodrugs/chemistry , Prodrugs/metabolism , Reactive Oxygen Species/analysis , Reactive Oxygen Species/metabolismABSTRACT
Sodium 4,4-dimethyl-4-silapentane-1-sulfonate (DSS) is the most widely accepted internal standard for protein NMR studies in aqueous conditions. Since its introduction as a reference standard, however, concerns have been raised surrounding its propensity to interact with biological molecules through electrostatic and hydrophobic interactions. While DSS has been shown to interact with certain proteins, membrane protein studies by solution-state NMR require use of membrane mimetics such as detergent micelles and, to date, no study has explicitly examined the potential for interaction between membrane mimetics and DSS. Consistent with its amphipathic character, we show DSS to self-associate at elevated concentrations using pulsed field gradient-based diffusion NMR measurements. More critically, DSS diffusion is significantly attenuated in the presence of either like-charged sodium dodecyl sulfate or zwitterionic dodecylphosphocholine micelles, the two most commonly used detergent-based membrane mimetic systems used in solution-state NMR. Binding to oppositely charged dodecyltrimethylammonium bromide micelles is also highly favourable. DSS-micelle interactions are accompanied by a systematic, concentration- and binding propensity-dependent change in the chemical shift of the DSS reference signal by up to 60 ppb. The alternative reference compound 4,4-dimethyl-4-silapentane-1-ammonium trifluoroacetate (DSA) exhibits highly similar behaviour, with reversal of the relative magnitude of chemical shift perturbation and proportion bound in comparison to DSS. Both DSS and DSA, thus, interact with micelles, and self-assemble at high concentration. Chemical shift perturbation of and modulation of micellar properties by these molecules has clear implications for their use as reference standards.
Subject(s)
Alkanesulfonic Acids/standards , Micelles , Nuclear Magnetic Resonance, Biomolecular/methods , Trimethylsilyl Compounds/standards , Alkanesulfonic Acids/metabolism , Detergents , Diffusion , Fluoroacetates/metabolism , Organosilicon Compounds/metabolism , Reference Standards , Trimethylsilyl Compounds/metabolismABSTRACT
Strategic delivery of IRDye 700DX (photosensitizer) is a key for improving its effect in photodynamic therapy. In this study, we have synthesized IRDye 700DX-conjugated polymers containing multiple cyclic RGD peptides to deliver IRDye 700DX selectively to tumor cells and tumor-associated blood vessels overexpressing αvß3 integrin. Our polymer has a backbone of hydrophilic poly(ethylene glycol)-poly(L-glutamic acid) block copolymer, and cyclic RGD peptides are conjugated to side chains of the poly(L-glutamic acid) while IRDye 700DX is conjugated to the terminal of poly(ethylene glycol). The polymers exhibited selective accumulation to the target sites in a subcutaneous solid tumor, and the accumulation was augmented with the increased number of cyclic RGD peptides. More importantly, the polymer containing 15 cyclic RGD peptides in one construct revealed preferential accumulation on the tumor-associated blood vessels without compromising penetration to deep portions of the tumor, thereby drastically inhibiting tumor growth upon photoirradiation, while the polymer containing 5 cyclic RGD peptides showed moderate antitumor activity despite efficient accumulation in the tumor with almost homogenous intratumoral distribution. These results suggest that controlling the intratumoral distribution of IRDye 700DX is critical for successful PDT, and our polymer containing multiple cyclic RGD peptides may be a promising carrier for this spatial control.
Subject(s)
Indoles/metabolism , Organosilicon Compounds/metabolism , Peptides, Cyclic/chemistry , Photosensitizing Agents/metabolism , Polyethylene Glycols/chemistry , Polyglutamic Acid/chemistry , Animals , Biological Transport , Cell Line, Tumor , Humans , Indoles/chemistry , Indoles/pharmacokinetics , Intracellular Space/metabolism , Mice , Organosilicon Compounds/chemistry , Organosilicon Compounds/pharmacokinetics , Photosensitizing Agents/chemistry , Photosensitizing Agents/pharmacokinetics , Tissue DistributionABSTRACT
Two novel silicon(IV) phthalocyanines bearing 1,3-bis[3(dimethylamino)phenoxy]propan-2-ol or 1,3-bis[3(diethylamino)phenoxy]propan-2-ol groups at their axial positions were synthesized. These phthalocyanines were converted into their water soluble derivatives by the quaternization reaction with methyl iodide. The quaternized phthalocyanines show excellent solubility aqueous solutions without any aggregation which makes them potential photosensitizers for use in photodynamic therapy (PDT). For this reason, the photophysical and photochemical properties such as fluorescence quantum yields, lifetimes, singlet oxygen generation and photodegradation of both non-ionic (3 and 5) and quaternized cationic silicon(IV) phthalocyanines were investigated. Furthermore, the cytotoxicity of PDT was determined by colorimetric proliferation assay against to hepatocellular carcinoma (HuH-7) cancer cells. In this study, the cells were incubated with a novel water soluble silicon(IV) phthalocyanine derivatives and thereafter the cells were illuminated using broad-band incoherent light source.
Subject(s)
Indoles/chemistry , Organosilicon Compounds/chemistry , Photosensitizing Agents/chemistry , Water/chemistry , Animals , Cattle , Cell Line, Tumor , Humans , Indoles/metabolism , Indoles/pharmacology , Models, Molecular , Molecular Conformation , Organosilicon Compounds/metabolism , Organosilicon Compounds/pharmacology , Photolysis , Photosensitizing Agents/metabolism , Photosensitizing Agents/pharmacology , Serum Albumin, Bovine/metabolism , Singlet Oxygen/chemistry , SolubilityABSTRACT
We report on the use of organosilica shells to couple gold nanorods to functional peptides and modulate their physiochemical and biological profiles. In particular, we focus on the case of cell penetrating peptides, which are used to load tumor-tropic macrophages and implement an innovative drug delivery system for photothermal and photoacoustic applications. The presence of organosilica exerts subtle effects on multiple parameters of the particles, including their size, shape, electrokinetic potential, photostability, kinetics of endocytic uptake and cytotoxicity, which are investigated by the interplay of colorimetric methods and digital holographic microscopy. As a rule of thumb, as the thickness of organosilica increases from none to â¼30nm, we find an improvement of the photophysical performances at the expense of a deterioration of the biological parameters. Therefore, detailed engineering of the particles for a certain application will require a careful trade-off between photophysical and biological specifications.
Subject(s)
Gold/chemistry , Nanotubes/chemistry , Organosilicon Compounds/chemistry , Cell Line , Drug Delivery Systems , Humans , Macrophages/metabolism , Organosilicon Compounds/metabolismABSTRACT
The aim of this investigation was to determine the effect of dose and adjuvant on uptake of two phosphite products (Phos-A and Phos-B) into Pinus radiata needles. In experiment 1, uptake of 6 kg ha-1 phosphite, applied as Phos-A, in 100 liters of water, together with an organosilicone superspreader (0.2%), was high (>60%). Uptake at doses greater than 6 kg ha-1 (12, 15, 18, and 24 kg ha-1) and applied in volumes less than 100 liters of water (75 and 50 liters) was poor (1 to 30%). Using stability tests and NMR spectroscopy in experiment 2, this appeared to be linked to a concentration dependent reaction resulting in the degradation of the organosilicone adjuvant that facilitated uptake of Phos-A. In experiment 3, uptake of phosphite applied as Phos-B, between 6 and 24 kg ha-1 in 100 liters of water, was tested alone and with four adjuvants (an organosilicone, alcohol ethoxylate, lecithin, and esterified seed oil). Uptake of Phos-B without any adjuvant was high (>50%) across all doses, indicating the formulation was optimized for P. radiata needles. Uptake of Phos-B increased with concentration up to 72% at 24 kg ha-1 in 100 liters of water. Symptoms of phytotoxicity were observed at rates of ≥12 kg ha-1. This study highlighted the effect of formulation, dose, concentration, and adjuvant on the uptake of phosphite into P. radiata needles.
Subject(s)
Phosphites , Pinus , Plant Leaves , Biological Transport/drug effects , Organosilicon Compounds/metabolism , Organosilicon Compounds/pharmacology , Phosphites/metabolism , Pinus/chemistry , Pinus/metabolism , Plant Leaves/chemistry , Plant Leaves/metabolismABSTRACT
A fundamental difference? A heme protein known to catalyze electron transfers was engineered into an enzyme that catalyzes the formation of C-Si bonds with >99 % ee. The new enzyme uses diazoesters as carbene donors for the insertion of various silanes into the Si-H bond. This is the first reported organosilicon-producing enzyme.
Subject(s)
Chemistry Techniques, Analytical/methods , Enzymes/genetics , Enzymes/metabolism , Heme/genetics , Organosilicon Compounds/metabolism , Protein Engineering , Silanes/chemistry , Catalysis , Esters/metabolism , Heme/metabolismABSTRACT
We report a comprehensive study on novel, highly efficient, and biodegradable hybrid molecular transporters. To this end, we designed a series of cell-penetrating, cube-octameric silsesquioxanes (COSS), and investigated cellular uptake by confocal microscopy and flow cytometry. A COSS with dense spatial arrangement of guanidinium groups displayed fast uptake kinetics and cell permeation at nanomolar concentrations in living HeLa cells. Efficient uptake was also observed in bacteria, yeasts, and archaea. The COSS-based carrier was significantly more potent than cell-penetrating peptides (CPPs) and displayed low toxicity. It efficiently delivered a covalently attached cytotoxic drug, doxorubicin, to living tumor cells. As the uptake of fluorescently labeled carrier remained in the presence of serum, the system could be considered particularly attractive for the inâ vivo delivery of therapeutics.
Subject(s)
Antineoplastic Agents/pharmacology , Cell-Penetrating Peptides/pharmacology , Doxorubicin/pharmacology , Drug Delivery Systems , Organosilicon Compounds/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Cell Survival/drug effects , Cell-Penetrating Peptides/chemistry , Cell-Penetrating Peptides/metabolism , Doxorubicin/chemistry , Doxorubicin/metabolism , Flow Cytometry , HeLa Cells , Humans , Microscopy, Confocal , Molecular Structure , Organosilicon Compounds/chemistry , Organosilicon Compounds/metabolismABSTRACT
RATIONALE: Compound-specific stable carbon isotope analysis by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) is widely used in studies of environmental or biological functioning. In the case of derivatized molecules, a calibration might be required due to added non-analyte carbon and in some cases non-stoichiometric recovery by the mass spectrometer. METHODS: Two biological materials of known isotopic composition were produced by microbial cell cultures on either (13) C-labelled glucose or non-labelled glucose as sole source of carbon. Subsequent hydrolyzed amino acids were derivatized as tert-butyldimethylsilyl (tBDMSi) derivatives and analyzed by GC/C/IRMS. The (13) C-enrichment measurements were used as a direct calibration to calculate the original (13) C/(12) C ratios of individual amino acids. We tested this calibration on both known and unknown samples. RESULTS: For the main proteinogenic amino acids we could determine the number of non-analyte added carbon atoms and assess the non-stoichiometrical recovery of tBDMSi carbon atoms, due to their incomplete oxidation in the combustion step of GC/C/IRMS. The calibration enabled the determination of the natural abundances (δ(13) C values) of amino acids with an average accuracy of ±1.1 . We illustrate the application of the calibration to determine the (13) C/(12) C ratios of amino acids, and the associated uncertainty, in biological and plant materials. CONCLUSIONS: The analysis of a labelled microbial cell culture offers a straightforward, rapid and reliable estimate of non-analyte carbon contribution to stable isotope composition. We recommend this method as a calibration or a control in artificial or natural (13) C-tracing experiments. Copyright © 2016 John Wiley & Sons, Ltd.
Subject(s)
Amino Acids/chemistry , Carbon Isotopes/analysis , Gas Chromatography-Mass Spectrometry/methods , Organosilicon Compounds/chemistry , Amino Acids/metabolism , Biomass , Calibration , Carbon Isotopes/metabolism , Organosilicon Compounds/metabolismABSTRACT
Stable isotope labeling experiments using mass spectrometry have been employed to investigate carbon flow levels (metabolic flux) in mammalian, plant, and microbial cells. To achieve a more precise (13)C-metabolic flux analysis ((13)C-MFA), novel fragmentations of tert-butyldimethylsilyl (TBDMS)-amino acids were investigated by gas chromatography-tandem mass spectrometry (GC-MS/MS). The product ion scan analyses of 15 TBDMS-amino acids revealed 24 novel fragment ions. The amino acid-derived carbons included in the five fragment ions were identified by the analyses of (13)C-labeled authentic standards. The identification of the fragment ion at m/z 170 indicated that the isotopic abundance of S-methyl carbon in methionine could be determined from the cleavage of C5 in the precursor of [M-159](+) (m/z 218). It was also confirmed that the precision of (13)C-MFA in Escherichia coli central carbon metabolism could be improved by introducing (13)C-labeling data derived from novel fragmentations. Graphical Abstract Novel collision-induced dissociation fragmentations of tert-butyldimethylsilyl amino acids were investigated and identified by GC-MS/MS.