Iron oxide nanoparticles with unique magnetic properties have a high potential for use in several biomedical, bioengineering and in vivo applications, including tissue repair, magnetic resonance imaging, immunoassay, drug delivery, detoxification of biologic fluids, cell sorting, and hyperthermia. Although various surface modifications are being done for making these nonbiodegradable nanoparticles more biocompatible, their toxic potential is still a major concern. The current in vitro study of the interaction of superparamagnetic iron oxide nanoparticles of mean diameter 30 nm coated with Tween 80 and murine macrophage (J774) cells was undertaken to evaluate the dose-and time-dependent toxic potential, as well as investigate the role of oxidative stress in the toxicity. A 15-30 nm size range of spherical nanoparticles were characterized by transmission electron microscopy and zeta sizer. MTT assay showed .95% viability of cells in lower concentrations (25-200 µg/mL) and up to three hours of exposure, whereas at higher concentrations (300-500 µg/mL) and prolonged (six hours) exposure viability reduced to 55%-65%. Necrosis-apoptosis assay by propidium iodide and Hoechst-33342 staining revealed loss of the majority of the cells by apoptosis. H 2 DCFDDA assay to quantify generation of intracellular reactive oxygen species (ROS) indicated that exposure to a higher concentration of nanoparticles resulted in enhanced ROS generation, leading to cell injury and death. The cell membrane injury induced by nanoparticles studied using the lactate dehydrogenase assay, showed both concentration-and time-dependent damage. Thus, this study concluded that use of a low optimum concentration of superparamagnetic iron oxide nanoparticles is important for avoidance of oxidative stress-induced cell injury and death.

Department of Pharmaceutics, Faculty of Pharmacy, Jamia Hamdard University, New Delhi, India AbstractObjective: In this study, attempt has been focused to prepare a nanoemulsion (NE) gel for topical delivery of amphotericin B (AmB) for enhanced as well as sustained skin permeation, in vitro antifungal activity and in vivo toxicity assessment. Materials and methods: A series of NE were prepared using sefsol-218 oil, Tween 80 and Transcutol-P by slow spontaneous titration method. Carbopol gel (0.5% w/w) was prepared containing 0.1% w/w AmB. Furthermore, NE gel (AmB-NE gel) was characterized for size, charge, pH, rheological behavior, drug release profile, skin permeability, hemolytic studies and ex vivo rat skin interaction with rat skin using differential scanning calorimeter. The drug permeability and skin irritation ability were examined with confocal laser scanning microscopy and Draize test, respectively. The in vitro antifungal activity was investigated against three fungal strains using the well agar diffusion method. Histopathological assessment was performed in rats to investigate their toxicological potential.Results and discussion: The AmB-NE gel (18.09 ± 0.6 mg/cm 2 /h) and NE (15.74 ± 0.4 mg/cm 2 /h) demonstrated the highest skin percutaneous permeation flux rate as compared to drug solution (4.59 ± 0.01 mg/cm 2 /h) suggesting better alternative to painful and nephrotoxic intravenous administration. Hemolytic and histopathological results revealed safe delivery of the drug. Based on combined results, NE and AmB-NE gel could be considered as an efficient, stable and safe carrier for enhanced and sustained topical delivery for AmB in local skin fungal infection. Conclusion: Topical delivery of AmB is suitable delivery system in NE gel carrier for skin fungal infection.

The core–shell polymeric nanofiber, owing to its better controlled release of embedded or encapsulated drugs in contrast with the single-compartment nanofibers, has been extensively studied for biomedical applications such as tissue engineering and wound healing. Electrospinning with co-axial needles is the dominant technique to fabricate nanofiber mat, however, associated with potential limitations such as high voltage requirement, costly equipment, slow deposition rate, required trained personal, not suitable in situ fabrication, and direct deposition of core–shell nanofibers on the wound at patient bedside. To address the above limitations, the work aims to introduce a novel co-axial airbrushing method to fabricate core–shell nanofibers using a simple setup and low-cost equipment, yet having a unique ability for fabrication at patient bedside and direct deposition on wound bed. Air-brush with a coaxial needle is designed to flow two different polymers solution with model biomolecules through core [PEO (polyethylene oxide)/poly-dl-lactide/PCL (polycaprolactone)] and shell (PCL/PEO) needle for the fabrication of the model core–shell nanofiber. Various processing parameters such as flow rate, air pressure, working distance, and concentration of polymer solution which affect the morphology of core–shell nanofibers were studied and found to have a prominent effect. The PCL–PEO nanofiber possesses a defined shell and core structure, tunable sustained release behavior of model proteins (bovine serum albumin and basic fibroblast growth factor; bFGF), and improved mechanical strength. In vitro interaction of human bone marrow-derived mesenchymal stem cells with core–shell fibers demonstrated the cytocompatibility and proliferative and differentiative (for bFGF loaded) properties of the core–shell nanofiber mat. Co-axial airbrushing can be used as a superior less-expensive technique for the fabrication of biomolecules/drug encapsulated core–shell fibers scaffold at patient bedside, which can mimic complex in vivo environment and could modulate cells behavior close to their in vivo condition for tissue regeneration and wound healing.

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Despite numerous advantages, multifunctional nanoparticles are still at an infancy stage. Many great achievements have been attained in this field to date, but many challenges still remain. A problem that limits the use of multifunctional nanoparticles is toxicity. If this toxicity can be overcome then the advancement in nanocomposite material science will be well on the way to a prospective treatment of cancer.