Fahima M. Helaly

This study focuses on fabricating and evaluating novel, ecofriendly, green, flexible, antimicrobial Styrene Butadiene Rubber vulcanizates for producing safety products. Styrene butadiene rubber (SBR) was compounded with ginger extract, a plant rich in bioactive phenolic compounds, and the conventional drugs, berberine and chitosan, in the ordinary mixer of rubber. Ginger ( Zingiber officinale ) extract was analyzed using HPLC. The rheological properties of the SBR mixes were analyzed to determine the optimal curing time. The compounded rubber mixes were then vulcanized at 152 °C. The prepared vulcanizates were evaluated using Fourier-transform infrared spectroscopy (FTIR), specific surface area measurements, mechanical, swelling, antimicrobial properties, and cytotoxicity analysis. The results showed that the physicochemical and mechanical properties of all vulcanizates remained robust, i.e., no significant degradation, even after exposure to thermal oxidative aging at 90 °C for seven days. Therefore, the change of tensile strength percentage after aging was 25, 5.56, 13, and 10% for free SBR, SBR/30 phr chitosan, SBR/20 phr ginger, and SBR/7 phr berberine, respectively. The cytotoxicity tests confirmed the safety of the investigated vulcanizates due to the negative results against the normal human fibroblast cell line (BJ1). Furthermore, the antimicrobial activity results demonstrated that the release of the various antimicrobial agents successfully inhibited the growth of different bacteria and fungi on the SBR rubber surface. The dielectric and electric findings highlighted the ability of the presence of bioactive agents to modify dielectric relaxation and conductivity in the investigated SBR vulcanizates and confirmed the utility of SBR composites contained 30 phr chitosan, 20 phr ginger, and 7 phr berberine as a good viable choice for antistatic and flexible electronic applications.

Developing a drug delivery strategy that can cross the blood–brain barrier is crucial to effective neurological treatment. In this work, a new strategy was introduced for efficient drug delivery of Donepezil based on the preparation of polyelectrolyte complexes (PEC) nanogel from β-chitosan (CS) and the prepared sulfonated styrene–maleic anhydride (S-SMA). First, low-molecular-weight SMA was prepared. Then, sulphonation of SMA was carried out. Three PEC nanoparticles were prepared by mixing three different ratios of S-SMA with β-chitosan. The structure and characteristics of the nanoparticles were thoroughly investigated. Varying S-SMA content (donated CS-S1, CS-S2, and CS-S3) for fixed a β-CS content, the surface charge and average size of the nanoparticles were tunable. Donepezil hydrochloride (DH) was encapsulated successfully in the nanoparticles CS-S3 and donated as CS-S3-DH. Additionally, the transmission electron microscopy (TEM) images revealed that almost 50% of the nanoparticles particles had diameters of 27 ± 0.1 and 111 ± 0.4 nm for CS-S3 and CS-S3-DH, respectively. The in vitro drug release study indicates a sustained release of DH for 72 h. In addition, the in vitro acetylcholinesterase (AChE) inhibitory was investigated. The result showed that AChE inhibitory percentages were 16.5 and 63.9% for CS-S3 and CS-S3-DH, respectively.

The goal of this research is to find the ideal formulation with the best antimicrobial performance in terms of rheological, physicomechanical, and lowest toxic properties to produce safety rubber for the children toy's and other industrial products. In order to accomplish this, a number of formulations containing ZnO as activator for vulcanization process as well as an antimicrobial agent at concentrations ranging from 1.5 to 40 phr in the presence of 40 phr of different fillers were prepared. The rheological characteristics of prepared compounded rubber samples were assessed and the cure rate was calculated. The overall rheological test results indicate a raise in minimum and maximum torque along with a fall in scorch and optimum cure time. The compounded NBR was vulcanized as estimated curing time. The results illustrated that the NBR vulcanizates containing various amounts of ZnO and 40 phr talc have the best physicomechanical properties. Also, the scanning electron micrographs indicated surface homogeneity and good dispersion of the NBR components. The cytotoxicity test of the investigated vulcanizates on normal retina cell line gave no cytotoxic effect which assessed their safety. These findings offer useful information for antimicrobial NBR vulcanizates for kid's toys and other safety products. Highlights: Synthesis of antimicrobial NBR rubber vulcanizates for safety applications. The antimicrobial agent used was ZnO. ZnO nanoparticles and other ingredients were incorporated with NBR on the ordinary rubber mixer. Rheological, physicomechanical properties and antimicrobial activity of NBR rubber were tested. The products have better mechanical and antimicrobial safety properties.

New amphiphilic triblock copolymers of poly(hexylene adipates) (PHA) and methoxy poly(ethylene glycol) (mPEG) having different hydrophobic/hydrophilic ratios were synthesized using a facile one-pot condensation reaction. Three samples of three different molecular weights were synthesized and characterized using different techniques. The synthesized copolymers were exploited to prepare core-shell nanoparticles with hydrophobic PHA and hydrophilic mPEG forming the core and shell, respectively. The drug loading efficiency and drug release properties of the mPEG-PHA-mPEG nanoparticles were investigated using 5-fluorouracil (5-FU) as a drug model. The drug loading efficacy of the nanoparticles was found to be dependent upon the polymer hydrophobicity. Drug release characteristics also depended on polymer hydrophobicity. The cytotoxicity of released 5-FU was monitoring as an antiproliferative agent against human liver cancer cell line (HEPG2) as well as antimicrobial against both gram-positive and gram-negative bacteria. Results of the in vitro cytotoxic activity of the released 5-FU showed a sustained antiproliferative potency against the tested human liver cancer cell line for 26 days. Besides, results of the antimicrobial study revealed that the most potent inhibitory activity was against S. aureus which shows hindrance zone of about 48 mm against the tested reference strain.

A new chelating terpolymer resin of sulphanilic acid–dithiooxamide–formaldehyde (SDTOF) was synthesized. Dithiooxamide–formaldehyde (DTOF) was prepared by the reaction of dithiooxamide and formaldehyde. These resins were characterized using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, and scanning electron microscopy. Chelating resins beads were applied for adsorption of nickel (II) ions by batch and column techniques. Sorption experiments were performed by varying pH, agitation time, sorbent dosage and initial concentration of nickel (II) ion solution. SDTOF and DTOF resins showed adsorption capacity of 188.3 and 99.8 mg g⁻¹, respectively. Nickel adsorption isotherms data were fitted to Langmuir isotherm. Kinetic studies showed the adsorption process followed pseudosecond‐order rate model. Desorption of Ni(II) ions was done using 0.1 M HCl, HNO₃, and ethylenediamine tetraacetic acid solutions. The reusability of SDTOF and DTOF resins for the removal of Ni(II) ions was also determined after 10 sorption−desorption cycles. POLYM. ENG. SCI., 55:163–172, 2015. © 2014 Society of Plastics Engineers

On the basis of monitoring the inhibition of the growth of human cancer cells, a series of novel furan derivatives of possessing a broader spectrum of antitumor activity and fewer toxic side effects than traditional anticancer drugs have been studied. Ten selected furan derivatives were subjected to a screening system for investigation of their antitumor potency against liver (HEPG2) cell line. Moreover, the biochemical effects of the selected furan derivatives on some enzymes such as aspartate and a lanine aminotransferases (ASTand ALT) and alkaline phosphatase (ALP), in addition to albumin, globulins, creatinine, total lipids, cholesterol, triglycerides and bilirubin in serum of mice were studied in comparison to 5-fluorouracil and doxorubicin. The antitumor activity results indicated that the selected furan derivatives showed growth of inhibition activity against the tested cell line but with varying intensities extents. Results of the biochemical investigations indicated that 5-fluorouracil and doxorubicin caused significant changes in the level of all parameters tested while treatment with the selected compounds showed slight, moderate or no significant changes.