Synergistic activity of combination therapy with PEGylated pemetrexed and gemcitabine for an effective cancer treatment

Designing Two-Dimensional Nanosheets for Improving Drug Delivery to Fucose-Receptor-Overexpressing Cancer Cells

Targeted drug delivery has shown promise in improving the therapeutic efficacy of anticancer drugs. Gemcitabine hydrochloride (GEM) is a broad-range chemotherapeutic agent for the treatment of various cancers. However, systemic use of free GEM is restricted because of its poor physicochemical properties and nonspecific drug delivery, resulting in dose-dependent adverse effects. In this study, a fucose-conjugated graphene oxide (GO)-based smart targeted nanocarrier system was designed to provide high loading, sustained release, and targeted high concentrations of GEM to cancer cells. Fucose-conjugated GO nanosheets (FGONS) and GEM-loaded fucose-conjugated GO nanosheets (GEM-FGONS) were prepared and characterized by various techniques. About 36.2 % of GEM was loaded to the FGONS, which showed a pH-dependent release over a period of 48 h. A colloidal suspension of GEM-FGONS was found to be physiochemically stable for up to 96 h. In cytotoxicity studies, GEM-FGONS demonstrated time- and dose-dependent high toxicities on fucose-receptor-overexpressing MDA-MB-231 human breast cancer cells and A549 human lung cancer cells. Moreover, targeted formulations were more efficacious than non-targeted or free GEM. Overall, bioconjugation of fucose helps in the stabilizing and targeting of graphene oxide nanosheets.

Specific inhibitor of Notch‑3 enhances the sensitivity of NSCLC cells to gemcitabine

Notch-3 is a receptor of the Notch signaling pathway and plays an important role in regulating self-renewal, differentiation and apoptosis in cancer cells. Overexpression of Notch-3 has been proved to be associated with resistance to gemcitabine (GEM) and poor patient prognosis for various malignant tumors. In the present study, two non-small cell lung cancer (NSCLC) cell lines, H1299 and A549, were induced with GEM for two months and then were treated with various concentrations of a Notch signaling blocker, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT), with the goal of reducing expression of Notch intracellular domain 3 (NICD3). Both cell lines were subsequently treated with either DAPT or DAPT combined with GEM and then viability, apoptosis, colony formation and cell count assays were performed. DAPT treatment effectively downregulated the expression of NICD3 in both cell lines. DAPT combined with GEM also significantly reduced the percentage of viable cells in both cell lines, while increasing the percentage of apoptotic cells, compared with GEM alone. In the clonogenicity assays, the combination of DAPT and GEM led to a decrease in clone numbers and significantly greater inhibition of the H1299 and A549 cells compared to treatment with DAPT or GEM alone. Meanwhile, levels of the apoptosis-related proteins, Bcl-2 and Bax, were found to be affected by the various treatments. Thus Notch-3 appears to be a promising target for gene therapy and DAPT is able to mediate a strong antitumor effect in NSCLC cells that overexpress Notch-3. Further studies of a combined treatment regimen with DAPT and GEM are warranted and may provide greater efficacy and safety in the treatment of NSCLC patients.

Novel Hyaluronic Acid Conjugates for Dual Nuclear Imaging and Therapy in CD44-Expressing Tumors in Mice In Vivo

Hyaluronic acid, a natural CD44 receptor ligand, has attracted attention in the past years as a macromolecular delivery of anticancer agents to cancer. At the same time, the clinical applications of Gemcitabine (Gem) have been hindered by its short biological half-life, high dose and development of drug resistance. This work reports the synthesis of a hyaluronic acid (HA) conjugate for nuclear imaging, and in vivo Gem delivery to CD44-expressing solid tumors in mice. HA was individually conjugated, via amide coupling, to Gem (HA-Gem), 4'-(aminomethyl)fluorescein hydrochloride (HA-4'-AMF) or tris(hydroxypyridinone) amine (HA-THP) for cancer therapy, in vitro tracking or single photon emission computed tomography/computed tomography (SPECT/CT) imaging, respectively. Gem conjugation to HA was directly confirmed by nuclear magnetic resonance (¹H NMR), gel permeation chromatography (GPC) and UV-visible spectrometry, or indirectly by a nucleoside transporter inhibition study. Gem conjugation to HA improved its plasma stability, reduced blood hemolysis and resulted in delayed cytotoxicity in vitro. Uptake inhibition studies in colon CT26 and pancreatic PANC-1 cells, by flow cytometry, revealed that uptake of fluorescent HA conjugate is CD44 receptor and macropinocytosis-dependent. Gamma scintigraphy and SPECT/CT imaging confirmed the relatively prolonged blood circulation profile and uptake in CT26 (1.5 % ID/gm) and PANC-1 (1 % ID/gm) subcutaneous tumors at 24 h after intravenous injection in mice. Four injections of HA-Gem at ~15 mg/kg, over a 28-day period, resulted in significant delay in CT26 tumor growth and prolonged mice survival compared to the free drug. This study reports for the first time dual nuclear imaging and drug delivery (Gem) of HA conjugates to solid tumors in mice. The conjugates show great potential in targeting, imaging and killing of CD44-over expressing cells in vivo. This work is likely to open new avenues for the application of HA-based macromolecules in the field of image-guided delivery in oncology.

Delivery of Dual Drug Loaded Lipid Based Nanoparticles across the Blood-Brain Barrier Impart Enhanced Neuroprotection in a Rotenone Induced Mouse Model of Parkinson's Disease

Parkinson's disease (PD) is the most widespread form of dementia where there is an age related degeneration of dopaminergic neurons in the substantia nigra region of the brain. Accumulation of α-synuclein (αS) protein aggregate, mitochondrial dysfunction, oxidative stress, and neuronal cell death are the pathological hallmarks of PD. In this context, amalgamation of curcumin and piperine having profound cognitive properties, and antioxidant activity seems beneficial. However, the blood-brain barrier (BBB) is the major impediment for delivery of neurotherapeutics to the brain. The present study involves formulation of curcumin and piperine coloaded glyceryl monooleate (GMO) nanoparticles coated with various surfactants with a view to enhance the bioavailability of curcumin and penetration of both drugs to the brain tissue crossing the BBB and to enhance the anti-parkinsonism effect of both drugs in a single platform. In vitro results demonstrated augmented inhibition of αS protein into oligomers and fibrils, reduced rotenone induced toxicity, oxidative stress, and apoptosis, and activation of autophagic pathway by dual drug loaded NPs compared to native counterpart. Further, in vivo studies revealed that our formulated dual drug loaded NPs were able to cross BBB, rescued the rotenone induced motor coordination impairment, and restrained dopaminergic neuronal degeneration in a PD mouse model.