Accessibility to biologics and its impact on disease activity and quality of life in patients with rheumatoid arthritis in Kuwait

Clinical Rheumatology - Biologics are indicated in rheumatoid arthritis (RA) in case of persistent high disease activity despite conventional disease-modifying anti-rheumatic drugs (cDMARDs) or...     

The relationship between the diameter of chemically-functionalized multi-walled carbon nanotubes and their organ biodistribution profiles in vivo

Carbon nanotubes (CNTs) exhibit unique properties which have led to their applications in the biomedical field as novel delivery systems for diagnosis and therapy purposes. We have previously reported that the degree of functionalization of CNTs is a key factor determining their biological behaviour. The present study broadens the spectrum by investigating the impact of the diameter of CNTs using two series of multi-walled CNTs (MWNTs) with distinct differences in their diameters. Both MWNTs were doubly functionalized by 1,3-dipolar cycloaddition and amidation reactions, allowing the appended functional groups to be further conjugated with radionuclide chelating moieties and antibodies or antibody fragments. All constructs possessed comparable degree of functionalization and were characterized by thermogravimetric analysis, transmission electron microscopy, gel electrophoresis and surface plasmon resonance. The MWNT conjugates were radio-labelled with indium-111, which thereby enabled in vivo single photon emission computed tomography/computed tomography (SPECT/CT) imaging and organ biodistribution study using γ-scintigraphy. The narrow MWNTs (average diameter: 9.2 nm) demonstrated enhanced tissue affinity including non-reticular endothelial tissues compared to the wider MWNTs (average diameter: 39.5 nm). The results indicate that the higher aspect ratio of narrow MWNTs may be beneficial for their future biological applications due to higher tissue accumulation.     

Translocation mechanisms of chemically functionalised carbon nanotubes across plasma membranes

Understanding the mechanisms responsible for carbon nanotube (CNT) internalisation into live cells is considered critical both from a fundamental point of view and for further engineering of CNT-based delivery systems to intracellular targets. While several studies are focused on the development of such CNT-based delivery systems, attempts to systematically elucidate the cellular uptake mechanisms of CNTs are still rather limited. The aim of the present study is to evaluate the cellular internalisation of chemically functionalised multi-walled carbon nanotubes (f-MWCNTs) in the presence of different well-known cellular uptake inhibitors. Our data reveal how f-MWCNTs are able to translocate across cell membranes of both phagocytic and non-phagocytic cell lines. We have evidenced that at least 30-50% of f-MWCNTs are taken up by cells through an energy-independent mechanism. This characteristic makes nanotubes loaded with therapeutic or diagnostic cargos extremely interesting as the release of active molecules directly into the cytoplasm increase their biological activity and therapeutic efficacy.     

Systemic antiangiogenic activity of cationic poly-L-lysine dendrimer delays tumor growth

This study describes the previously unreported intrinsic capacity of poly-L-lysine (PLL) sixth generation (G₆) dendrimer molecules to exhibit systemic antiangiogenic activity that could lead to solid tumor growth arrest. The PLL-dendrimer-inhibited tubule formation of SVEC4-10 murine endothelial cells and neovascularization in the chick embryo chick chorioallantoic membrane (CAM) assay. Intravenous administration of the PLL-dendrimer molecules into C57BL/6 mice inhibited vascularisation in Matrigel plugs implanted subcutaneously. Antiangiogenic activity was further evidenced using intravital microscopy of tumors grown within dorsal skinfold window chambers. Reduced vascularization of P22 rat sarcoma implanted in the dorsal window chamber of SCID mice was observed following tail vein administration (i.v.) of the PLL dendrimers. Also, the in vivo toxicological profile of the PLL-dendrimer molecules was shown to be safe at the dose regime studied. The antiangiogenic activity of the PLL dendrimer was further shown to be associated with significant suppression of B16F10 solid tumor volume and delayed tumor growth. Enhanced apoptosis/necrosis within tumors of PLL-dendrimer-treated animals only and reduction in the number of CD31 positive cells were observed in comparison to protamine treatment. This study suggests that PLL-dendrimer molecules can exhibit a systemic antiangiogenic activity that may be used for therapy of solid tumors, and in combination with their capacity to carry other therapeutic or diagnostic agents may potentially offer capabilities for the design of theranostic systems.     

Doxorubicin-loaded lipid-quantum dot hybrids: surface topography and release properties

A few studies have attempted to combine the physicochemical versatility offered by the liposome structure with the superior optical characteristics of quantum dots (QD) for the construction of multifunctional nanoparticles. We are reporting the construction of drug-loaded liposome-QD hybrid vesicles (L-QD) by incorporating TOPO-capped, CdSe/ZnS QD into the two types of lipid bilayers: the ‘rigid’ disteroylphosphatidylcholine (DSPC:Chol:DSPE-PEG₂₀₀₀) and a fluid-phase bilayer of egg PC (EPC:Chol:DSPE-PEG₂₀₀₀). Structural characterization of L-QD hybrid vesicles using atomic force microscopy (AFM) revealed that the incorporation of QD took place by hydrophobic self-association within the membranes. The encapsulation of hydrophilic small molecules in the internal aqueous phase of the L-QD hybrids showed different degrees of carboxyfluorescein (CF) release in buffer and serum, depending on the type of lipid used. The presence of QD in the lipid bilayer increased the CF release from EPC fluid bilayer. On the other hand, (DSPC) L-QD hybrids showed a higher stability under the same conditions with minimal CF leakage. Furthermore, (DSPC) L-QD hybrids showed a stable mean diameter up to three weeks stored at 4 °C, 25 °C, and 40 °C, determined by photo correlation spectroscopy (PCS) analysis. Finally, doxorubicin (Dox) was loaded into L-QD hybrids using the osmotic gradient technique and with at least 97% loading efficiency. The fluorescence spectrum of Dox was simultaneously detected with that of green-emitting QD that indicated the coexistence of QD and Dox in a single vesicle system. In conclusion, the drug-loaded L-QD-Dox hybrid vesicles presented here constitute a promising multifunctional delivery vector capable of transporting combinations of therapeutic and diagnostic modalities.     

Cell uptake, cytoplasmic diffusion and nuclear access of a 6.5 nm diameter dendrimer

Macromolecular crowding and the presence of organelles in the cytosol present barriers to particle mobility, such that it is unclear how nano-carriers can deliver their active agents to the nucleus. In this work a sixth generation amino terminated polyamide polylysine dendrimer (Gly-Lys(63) (NH(2))(64)) (MW 8149, diameter 6.5 nm) which is fluorescent allowed the study of nuclear uptake and mobility in living lung carcinoma (SK/MES-1) and colon adenocarcinoma (Caco-2) cells. The dendrimer is found within 25-45 min of incubation inside the cell nuclei. Living cells were then used to develop a method for the dynamic nuclear uptake study using confocal microscopy. The dynamic uptake of the dendrimer demonstrated here allowed the apparent cytoplasmic diffusion coefficient (D) of the dendrimer to be calculated. Values were found in the range 5.99 x 10(-11)cm(2)s(-1) (SK/MES-1 cells) to 9.82 x 10(-11)cm(2)s(-1) (Caco-2 cells). The difference must reflect variation in the intracellular architecture of the cell types.     

Saffron: a potential candidate for a novel anticancer drug against hepatocellular carcinoma

Saffron has been proposed as a promising candidate for cancer chemoprevention. The purpose of this investigation was to investigate the chemopreventive action and the possible mechanisms of saffron against diethylnitrosamine (DEN)-induced liver cancer in rats. Administration of saffron at doses of 75, 150, and 300 mg/kg/day was started 2 weeks prior to the DEN injection and was continued for 22 weeks. Saffron significantly reduced the DEN-induced increase in the number and the incidence of hepatic dyschromatic nodules. Saffron also decreased the number and the area of placental glutathione S-transferase-positive foci in livers of DEN-treated rats. Furthermore, saffron counteracted DEN-induced oxidative stress in rats as assessed by restoration of superoxide dismutase, catalase, and glutathione-S-transferase levels and diminishing of myeloperoxidase activity, malondialdehyde and protein carbonyl formation in liver. The results of immunohistochemical staining of rat liver showed that saffron inhibited the DEN-mediated elevations in numbers of cells positive for Ki-67, cyclooxygenase 2, inducible nitric oxide synthase, nuclear factor-kappa B p-65, and phosphorylated tumor necrosis factor receptor. Saffron also blocked the depletion in the number of cells positive for TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling) and M30 CytoDeath in liver tissues of DEN-treated rats. In vitro experiments carried out using HepG2 cells also confirmed these findings and showed inhibition of nuclear factor-kappa B activation, increased cleavage of caspase-3, as well as DNA damage and cell cycle arrest upon saffron treatment. Conclusion: This study provides evidence that saffron exerts a significant chemopreventive effect against liver cancer through inhibition of cell proliferation and induction of apoptosis. This report also shows some evidence that saffron protects rat liver from cancer via modulating oxidative damage and suppressing inflammatory response.     

Functional motor recovery from brain ischemic insult by carbon nanotube-mediated siRNA silencing

Stroke is the second cause of death worldwide with ischemic stroke accounting for 80% of all stroke insults. Caspase-3 activation contributes to brain tissue loss and downstream biochemical events that lead to programmed cell death after traumatic brain injury. Alleviation of symptoms following ischemic neuronal injury can be potentially achieved by either genetic disruption or pharmacological inhibition of caspases. Here, we studied whether silencing of Caspase-3 using carbon nanotube-mediated in vivo RNA interference (RNAi) could offer a therapeutic opportunity against stroke. Effective delivery of siRNA directly to the CNS has been shown to normalize phenotypes in animal models of several neurological diseases. It is shown here that peri-lesional stereotactic administration of a Caspase-3 siRNA (siCas 3) delivered by functionalized carbon nanotubes (f-CNT) reduced neurodegeneration and promoted functional preservation before and after focal ischemic damage of the rodent motor cortex using an endothelin-1 induced stroke model. These observations illustrate the opportunity offered by carbon nanotube-mediated siRNA delivery and gene silencing of neuronal tissue applicable to a variety of different neuropathological conditions where intervention at well localized brain foci may offer therapeutic and functional benefits.