Ferrocene/ ß-cyclodextrin based supramolecular nanogels as theranostic systems.

A supramolecular redox responsive nanogel (NG) with the ability to sense cancer cells and loaded with a releasing therapeutic agent was synthesized using hostguest interactions between polyethylene glycol-grafted-ß-cyclodextrin and ferrocene boronic acid. Cyclic voltammetry matched with other spectroscopy and microscopy methods provided strong indications regarding host-guest interactions and formation of the NG. Moreover, the biological properties of the NG were evaluated using fluorescence silencing, confocal laser scanning microscopy, and cell toxicity assays. Nanogel with spherical core-shell architecture and 100-200 nm sized nanoparticles showed high encapsulation efficiency for doxorubicin (DOX) and luminol (LU) as therapeutic and sensing agents. High therapeutic and sensing efficiencies were manifested by complete release of DOX and dramatic quenching of LU fluorescence triggered by 0.05 mM H2O2 (as an ROS component). The NGs showed high ROS sensitivity. Taking advantage of a high loading capacity, redox sensitivity, and biocompatibility, the NGs can be used as strong theranostic systems in inflammation-associated diseases.

Stimuli-responsive natural gums-based drug delivery systems for cancer treatment.

Chemotherapy as the main cancer treatment method has non-specific effects and various side-effects. Accordingly, significant attempts have been conducted to enhance its efficacy through design and development of "smart" drug delivery systems (DDSs). In this context, natural gums, as a nice gift by the nature, can be exploited as stimuli-responsive DDSs for cancer treatment in part due to their renewability, availability, low cost, bioactivity, biocompatibility, low immunogenicity, biodegradability, and acceptable stability in both in vitro and in vivo conditions. However, some shortcomings (e.g., poor mechanical properties and high hydration rate) restrict their biomedical application ranges that can be circumvented through modification process (e.g., grafting of stimuli-responsive polymers or small molecules) to obtain tailored biomaterials. This review article aimed to compile the stimuli-responsive DDSs based on natural gums. In addition, different types of stimuli, the fundamental features of natural gums, as well as their chemical modification approaches are also shortly highlighted.

A novel bioreducible and pH-responsive magnetic nanohydrogel based on ß-cyclodextrin for chemo/hyperthermia therapy of cancer.

A new strategy for design and development of a magnetic "smart" drug delivery system (DDS) based on ß-cyclodextrin (ß-CD) and poly(2-ethyl-2-oxazoline) (PEtOx) was reported. For this purpose, a ß-CD-(I)7 was acetylated, and then EtOx monomer was grafted onto the acetylated ß-CD-(I)7 through cationic ring-opening polymerization followed by simultaneous crosslinking with amine-end capped Fe3O4 nanoparticles (Fe3O4-NH2 NPs) and cystamine to produce a ß-CD-g-(PEtOx)7/Fe3O4 as a reduction- and pH-responsive magnetic DDS. The developed magnetic nanohydrogel was loaded with doxorubicin hydrochloride (Dox), and its drug loading and encapsulation efficiencies, as well as its pH- and reduction-triggered drug release behaviors were investigated. The anticancer activity of the formulated ß-CD-g-(PEtOx)7/Fe3O4-Dox was investigated against MCF7 cells. According to the results, the formulated ß-CD-g-(PEtOx)7/Fe3O4-Dox can be considered as an efficient and "smart" DDS for cancer therapy and diagnosis due to its high drug loading value (∼ 74 %), slow and stimuli-triggered drug release behavior, and acceptable magnetic properties.

Boronic Acid-Functionalized Two-Dimensional MoS2 at Biointerfaces.

While noncovalent interactions at two-dimensional nanobiointerfaces are extensively investigated, less knowledge about covalent interactions at this interface is available. In this work, boronic acid-functionalized 2D MoS2 was synthesized and its covalent multivalent interactions with bacteria and nematodes were investigated. Polymerization of glycidol by freshly exfoliated MoS2 and condensation of 2,5-thiophenediylbisboronic acid on the produced platform resulted in boronic acid-functionalized 2D MoS2. The destructive interactions between 2D MoS2 and bacteria as well as nematodes were significantly amplified by boronic acid functional groups. Because of the high antibacterial and antinematodal activities of boronic acid-functionalized 2D MoS2, its therapeutic efficacy for diabetic wound healing was investigated. The infected diabetic wounds were completely healed 10 days after treatment with boronic acid-functionalized 2D MoS2, and a normal structure for recovered tissues including different layers of skin, collagen, and blood vessels was detected.

Fabrication of new generation of co-delivery systems based on graphene-g-cyclodextrin/chitosan nanofiber.

Although many techniques have been devoted to promote therapeutic purposes of drug carrier systems, however, there are still many challenges in this area. Here, we designed co-loaded delivery systems, composed of curcumin loaded cyclodextrin-graphene oxide core (Cur@CD-GO) and gallic acid loaded chitosan shell nanofibers (Cur-Ga NF), which can promote the therapeutic efficiency of drugs. The synthesized nanofibres were fabricated by electrospinning technique with the coaxial system. Results showed that co-loaded delivery systems (Cur-Ga NF) provide better performance over single drug-loaded NFs (Cur@CD-GO). It was demonstrated that the nanofibers were successfully prepared, and the drugs in the core and sell of nanofibers were released in a controlled and sustained manner. The produced Cur-Ga NF, providing improved anti-cancer activity, antimicrobial activity, antioxidant activity and anti-inflammatory outcome as compared to single drug-loaded NFs. Our investigations showed that such co-delivery fiber systems could be employed as a promising nanocarrier for therapeutic applications.

Preparation of new GO-based slide ring hydrogel through a convenient one-pot approach as methylene blue absorbent.

Slide ring hydrogels (SRHG) with supramolecular structures are a new class of hydrogels that contrary to the traditional hydrogels comprise dynamic cross-linking points. Herein, we reported on the fabrication of a new slide ring hydrogel through a very convenient one-pot approach. In this regard, isocyanate functionalized GO was synthesized and used as a stopper as well as cross-linker in the presence of a polypseudorotaxane of cyclodextrin threaded on poly(ethylene glycol) (PR). The surface of the resulting SRHG modified via graft polymerization with polyacrylamide (PAAm) and its application as a new type of absorbent for wastewater treatment was studied. Due to its porous structure and its high content of surface functional groups, the synthesized hydrogel was able to efficiently remove cationic dye methylene blue (MB) from wastewater in a short time. The maximum adsorption capacity of the resulting hydrogel was 92.3 mg/g which exhibited an almost 100% increment as compared to that of untreated GO. The adsorption mechanism of MB was also investigated. The kinetic data, obtained at the optimum pH 7, were fitted well with the pseudo-second-order model. Results from degradation and recycling experiments toward MB showed that the SRHG was stable and reusable.

Bioconjugated graphene oxide hydrogel as an effective adsorbent for cationic dyes removal.

In this study, graphene oxide - cellulose nanowhiskers nanocomposite hydrogel was easily synthesized through covalent functionalization of cellulose nanowhiskers with graphene oxide via a facile approach. The nitrene chemistry applied for covalent functionalization of graphene oxide sheets. The surface morphology and chemical structure of the nanocomposite hydrogel were characterized by FTIR, TGA, Raman, XRD, elemental analysis and SEM. The UV/Visible absorption spectrum revealed that the obtained porous nanocomposite hydrogel can efficiently remove cationic dyes such as methylene blue (MB) and Rhodamine B (RhB) from wastewater with high absorption power. The adsorption process showed that 100% of MB and 90% of RhB have been removed and the equilibrium state has been reached in 15min for low concentration solutions in accordance with the pseudo-second-order model. Moreover, the sample exhibited stable performance after being used several times. High adsorption capacity and easy recovery are the efficient factors making these materials as good adsorbent for water pollutants and wastewater treatment.

Management of patients with metastatic gestational trophoblastic tumor.

OBJECTIVE: This study was designed to analyze the results of treatment on patients with metastatic gestational trophoblastic tumor (metastatic GTT). METHOD: During 1996-2001, 38 cases with metastatic GTT were diagnosed and received treatment in Vali-e-Asr Hospital, Tehran, Iran. Data were gathered retrospectively and analyzed based on therapy and response rate. Sixteen patients initially labeled as low-risk, four as middle-risk and eighteen as high-risk patients according to FIGO scoring system (1992). Thirty-four (89.5%) patients responded to treatment; 13 to single-agent [methotrexate (MTX) or ACT] and 21 to multiagent chemotherapy [EMA/cisplatinum and etoposide (EMA-EP) or MTX, ACT-D and cyclophosphamide or chlorambucil (MAC)]. RESULTS: All low-risk patients, 2 middle-risk patients and 16 high-risk patients responded to treatment. Four cases failed to respond to therapy due to CNS involvement. CONCLUSIONS: Patients with low-risk metastatic GTT have a 100% chance to response to single-agent chemotherapy and those with high-risk disease have great chance to response to multiagent chemotherapy such as EMA-EP.