Sharif Digital Repository

Polycitric acid was conjugated onto the surface of carbon nanotubes (CNTs), and hybrid nanomaterials containing CNT axis and polycitric acid branches that were highly soluble in aqueous solutions were synthesized. In this work, pristine MWCNTs were opened and functionalized through treatment with acid, then polycitric acid was covalently grafted onto their surface by the "grafting from" approach based on polycondensation of citric acid in the melting state. The chemical structure, morphology, thermal properties and size of MWCNT-g-PCA hybrid materials were investigated by IR, 13C NMR, 1H NMR, TEM, TGA, DSC and DLS. To investigate the biocompatibility of the synthesized hybrid nanomaterials... 

This work presents a procedure for functionalization of graphene sheets from edges by polyglycerol. Hyperbranched polyglycerol with a bi-dentate aromatic segment in its focal point was synthesized and used to sandwich graphene sheets from the cut-edges. Due to the hydrophobicity of the flat surface of the edge-functionalized graphenes and hydrophilicity of their edges, they changed their conformation from the extended- to the closed-state and formed nanocapsules in aqueous solutions. Spectroscopy and microscopy evaluations showed that the average size for nanocapsules is 300 nm. They were able to encapsulate hydrophobic molecules such as doxorubicin in aqueous solutions with a high loading... 

A noncovalent functionalization of the edges of reduced graphene oxide (RGO) with β-cyclodextrin-graft-hyperbranched polyglycerol (β-CD-g-HPG) was successfully performed via a host-guest interaction. The results showed that β-CD-g-HPG disperses the graphene sheets better than pure β-CD or HPG. The resulted supramolecular structure is stable in neutral water medium more than one week. However, in acidic medium the host-guest interaction is collapsed and graphene nanosheets precipitate. © 2017, Copyright © Taylor & Francis  

In this work, a novel carrier based-on modified graphene oxide was designed for co-delivery of hydrophobic and hydrophilic anticancer drugs (curcumin (Cur) and doxorubicin (DOX) as the model of drugs). The hydroxyl groups at the edges of graphene oxide (GO) sheets were used as the initiation sites for growing poly(epichlorohydrin) (PCH) chains. Then, hyperbranched polyglycerol (HPG) was grafted on the hydroxyl end groups of PCH (PCH-g-HPG). Pendant chlorines in the main chain of GO-PCH-g-HPG were replaced with hydrazine. The modification of GO sheets with oxygen-rich polymers increased water solubility of graphene oxide. Doxorubicin was loaded onto the nanocarrier by covalent bonding with... 

Paclitaxel as one of the most effective anticancer drugs has low aqueous solubility. This inevitably reveals its commercial formulation in Cremophor EL®/ethanol mixture. However, this formulation leads to several severe side effects such as hypersensitivity reactions, neurotoxicity and nephrotoxicity. Inclusion complexation has been introduced as a practical approach in increasing paclitaxel aqueous solubility. To this end, a hybrid nanocarrier system based on hyperbranched polyglycerol and β-cyclodextrin is designed with key components uniquely structured at nanoscale and evaluated according to medical requirements. Paclitaxel is included in the hydrophobic cavity of cyclodextrin as guest... 

Multistimuli-responsive hyperbranched polymers were synthesized in one-step polymerization using reversible addition-fragmentation chain transfer self-condensing vinyl polymerization (RAFT-SCVP). These hyperbranched polymers responded to UV-vis or sunlight, pH changes, and temperature changes. 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid known as DDMAT participated in esterification with 2-hydroxyethyl methacrylate to obtain a chain transfer monomer in the name of 2-((2-(((dodecylthio)carbonothioyl)thio)-2-methylpropanoyl)oxy)ethylmethacrylate (MACDT). For the first time, smart hyperbranched polymers were produced with the RAFT-SCVP method in one step by using... 

With the high rate of mortality associated with breast cancer among women, breast cancer treatment has attracted great deal of attention globally. To reduce the exposure of body organs to high cytotoxicity of the common chemotherapeutic drugs, local co-delivery of selected chemotherapeutics has emerged as a solution. In this work, an electrospun composite including a co-drug-loaded graphene oxide-based nanocarrier is fabricated for local anticancer applications. To increase dispersion and cellular uptake of graphene oxide (GO), first, the hydroxyl groups at the edges of GO are grafted by poly (epichlorohydrin) (PCH) to form GO-PCH. Then, the hydroxyl end groups of PCH are grafted (g) with... 

Linear-dendritic triblock copolymers of linear poly(ethylene glycol) and hyperbranched poly(citric acid) (PCA-PEG-PCA) were used as the reducing and capping agents to encapsulate gold and silver nanoparticles (AuNPs and AgNPs). PCA-PEG-PCA copolymers in four different molecular weights were synthesized using 2, 5, 10 and 20 citric acid/PEG molar ratios and were called A 1, A 2, A 3 and A 4, respectively. Nanoparticles were encapsulated simultaneously during the preparation process. AuNPs were simply synthesized and encapsulated by addition a boiling aqueous solution of HAuCl 4 to aqueous solutions of A 1, A 2, A 3 and A 4. In the case of silver, an aqueous solution of AgNO 3 was reduced... 

Linear-dendritic copolymers containing hyperbranched poly(citric acid) and linear poly(ethylene glycol) blocks (PCA-PEG-PCA) were used as reducing and capping agents to synthesize and support gold nanoparticles (AuNPs). PCA-PEG-PCA copolymers with 1758, 1889 and 3446 molecular weights, called A1, A2 and A3 through this work, respectively, were synthesized using 2, 5, and 10 citric acid/PEG molar ratios. The diameter of A1, A2 and A3 in a fresh water solution was investigated using dynamic light scattering (DLS) and it was between 1.8 and 2.8 nm. AuNPs were simply synthesized and supported by addition a boiling aqueous solution of HAuCl4 to aqueous solutions of A1, A2 and A3. Supported AuNPs... 

New biocompatible and water soluble hybrid materials containing multi-wall carbon nanotubes (MWCNTs) as core and hyperbranched polyglycerol (PG) as shell were synthesized successfully. In this work, pristine MWCNTs were opened and functionalized through treatment with acid and polyglycerol was covalently grafted onto their surface by the "grafting from" approach based on in-situ ring-opening polymerization of glycidol. Some short-term In vitro cytotoxicity and hemocompatibility tests were conducted on HT1080 cell line (human Fibrosarcoma), because this epithelial cell line can be one of the first route of entry of the exogenous materials to the vascular system and therefore subsequent... 

Multistimuli-responsive hyperbranched polymers were synthesized in one-step polymerization using reversible addition-fragmentation chain transfer self-condensing vinyl polymerization (RAFT-SCVP). These hyperbranched polymers responded to UV-vis or sunlight, pH changes, and temperature changes. 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid known as DDMAT participated in esterification with 2-hydroxyethyl methacrylate to obtain a chain transfer monomer in the name of 2-((2-(((dodecylthio)carbonothioyl)thio)-2-methylpropanoyl)oxy)ethylmethacrylate (MACDT). For the first time, smart hyperbranched polymers were produced with the RAFT-SCVP method in one step by using... 

The synthesis of a new drug delivery system based on hybrid nanomaterials containing a β-CD core and hyperbranched PG is described. Conjugating PG branches onto β-CD not only increases its water solubility but also affects its host/guest properties deeply. It can form molecular inclusion complexes with small hydrophobic guest molecules such as ferrocene or FITC with reasonable release. In addition, the achievable payloads are significantly higher as for carriers such as hyperbranched PGs. Short-term in vitro cytotoxicity and hemocompatibility tests on L929 cell lines show that the hybrid nanomaterial is highly biocompatible. Due to their outstanding properties, β-CD-g-PG hybrid nanomaterials... 

Cancer is a deadly disease that has long plagued humans and has become more prevalent in recent years. The common treatment modalities for this disease have always faced many problems and complications, and this has led to the discovery of strategies for cancer diagnosis and treatment. The use of magnetic nanoparticles in the past two decades has had a significant impact on this. One of the objectives of the present study is to introduce the special properties of these nanoparticles and how they are structured to load and transport drugs to tumors. In this study, iron oxide (Fe3O4) nanoparticles with 6 nm sizes were coated with hyperbranched polyglycerol (HPG) and folic acid (FA). The... 

Linear-dendritic ABA triblock copolymers containing poly(ethylene glycol) (PEG) as B block and hyperbranched poly(citric acid) (PCA) as A blocks were synthesized through polycondensation. The molecular self-assembly of synthesized PCA-PEG-PCA copolymers in water led to formation of nanoparticles and fibers in different sizes and shapes depending on the time and size of PCA blocks. Ten days after dissolving PCA-PEG-PCA copolymers in water, the size of fibers had reached several millimeters. Mixing a water solution of fluorescein as a small guest molecule and PCA-PEG-PCA copolymers led to the encapsulation of fluorescein by products of molecular self-assembly. To investigate their potential... 

Hyperbranched polyethyleneimine functionalized silica (PEI-SiO2) nanoparticles with considerable hydrophilicity were synthesized and incorporated into a polysulfone (PSF)/dimethylacetamide (DMA)/polyvinylpyrrolidone (PVP) membrane casting solution in five different ratios to fabricate PEI-SiO2/PSF nanocomposite membranes using nonsolvent-induced phase separation. The hydrophilic PEI-SiO2 nanoparticles were characterized by TEM, FTIR, TGA, and XPS analyses. Morphology, water contact angles, mean pore sizes, overall porosity, tensile strengths, water flux, antifouling and the dye separation performances of the PEI-SiO2/PSF membranes were also studied. The PEI-SiO2 nanoparticles were uniformly... 

Fully supramolecular dendrosomes (FSD) as bi-phase drug delivery systems are reported in this work. For preparation of FSD, amphiphilic linear-dendritic supramolecular systems (ALDSS) have been synthesized by host-guest interactions between hyperbranched polyglycerol having β-cyclodextrin core and bi-chain polycaprolactone (BPCL) with a fluorescine focal point. Self-assembly of ALDSS in aqueous solutions led to FSD. They were able to encapsulate paclitaxel with a high loading capacity. The dendrosome-based drug delivery systems were highly sensitive to pH and temperature. They were stable at 20-37. °C and pH7-8, but dissociated and released drug at temperatures lower than 20. °C or higher...