Nanomedicine Journal
Volume:2 Issue: 3, Summer 2015

In the last decade, developments in nanotechnology have provided a new field in medicine called “Nanomedicine”. Nanomedicine has provided new tools for photodynamic therapy. Quantum dots (QDs) are approximately spherical nanoparticles that have attracted broad attention and have been used in nanomedicine applications. QDs have high molar extinction coefficients and photoluminescence quantum yield, narrow emission spectra, broad absorption, large effective stokes shifts. QDs are more photostable and resistant to metabolic degradation. These photosensitizing properties can be used as photosensitizers for Photodynamic Therapy (PDT). PDT has been recommended for its unique characteristic, such as low side effect and more efficiency. Therefore, nanomedicine leads a promising future for targeted therapy in cancer tumor. Furthermore, QDs have recently been applied in PDT, which will be addressed in this review letter. Also this review letter evaluates key aspects of nano-particulate design and engineering, including the advantage of the nanometer scale size range, biological behavior, and safety profile.

Despite of wide range applications of polymeric nanoparticles in protein delivery, there are some problems for the field of protein entrapment, initial burst and controlled release profile. In this study, we investigated the influence of some changes in PLGA nanoparticles formulation to improve the initial and controlled release profile. Selected parameters were: pluronic F127, polysorbate 80 as surfactant, pH of inner aqueous phase, L/G ratio of PLGA polymer, volume of inner aqueous phase and addition of polyvinylpyrrolidone as an excipient. FITC-HSA was used as a model hydrophilic drug. The nanoparticles were prepared by nanoprecipitation. Initial release of FITC-HSA from PLGA-tween 80 nanoparticles (opt-4, 61%) was faster than control (PLGA-pluronic) after 2.30 h of incubation. Results showed that decrease in pH of inner aqueous phase to pI of protein can decrease IBR but the release profile of protein is the same as control. Release profile with three phases including a) initial burst b) plateau and c) final release phase was observed when we changed volume of inner aqueous phase and L/G ratio in formulation. Co-entrapment of HSA with PVP and pluronic reduced the IBR and controlled release profile in opt-19. Encapsulation efficiency was more than 97% and nanoparticles size and zeta potentials were mono-modal and -18.99 mV, respectively. In this research, we optimized a process for preparation of PLGA-PVP-pluronic nanoparticles of diameter less than 300 nm using nanoprecipitation method. This formulation showed a decreased initial burst and long lasting controlled release profile for FITC-HSA as a model drug for proteins.

Nowadays hydrogels are one of the upcoming classes of polymer-based controlled-release drug delivery systems. Temperature and pH-responsive delivery systems have drawn much attention because some diseases reveal themselves by a change in temperature and/or pH. The objective of this work is to prepare and characterize composite membrane using responsive nanoparticles into a polymer matrix. These nanoparticles were made of the copolymer poly (N-isopropylacrylamide-co-methaçrylic acid) by an aqueous dispersion polymerization process and are responsible for dual sensitivity to temperature and pH. Morphology study with SEM, swelling behavior with Dynamic Light Scattering Technique, in vitro drug release behavior with side-by-side Diffusion Cells were also investigated in this paper. Doxorubicin hydrochloride was used as a model solute. The study on the release of doxorubicin hydrochloride showed that the release rate was higher at pH 5 than pH 7.4, increased with the increase of temperature. Nevertheless, ionic strength only poses a minor direct effect at higher pH. Such system may be potentially used as a tumor-targeting doxorubicin hydrochloride delivery in the body.

Copper oxidenanoparticles have different industrial applications so it is inevitable that nanoparticulate products finally find their way into aquatic ecosystems. Nevertheless there is little information available about their effects on some of edible fish. The present study aims to determine the acute toxicity and evaluate the effect of two sub-acute concentrations (50 and 70% 96 h LC50) of CuO-NPs on some hematological and biochemical parameters of R. rutilus. 225 healthy specimen of R. rutilus (mean weight 5.52±1.2 g; mean length 6.20±0.2 cm) were transported to the laboratory. In order to prepare the stock solution, CuO-NPs was dispersed in pure water with ultrasonication (50-60 kHz) for 15 min every day before dosing. At first, R. rutilus was exposed to CuO-NPs to determine the lethal concentration (LC50) value. Following acute test, fish were treated with sub-acute concentrations of CuO-NPs (50 and 70% 96 h-LC50 at) with one control group (no CuO-NPs) for a week to determine the changes in the level of some plasma hematological and biochemical parameters. The 96 h-LC50 values of CuO-NPs was 2.19±0.003 mg/l. R. rutilus exhibited significantly lower RBC count, Hb and Hct values and a significant increase in the WBC numbers, MCH, MCHC and MCV indices (p<0.05). Low glucose and higher cortisol content in plasma were observed in the fish exposed to CuO nanoparticles than those in control group (p<0.05). These alterations indicate R. rutilus sensitivity to CuO-NPs and changes in blood parameters would be a useful tool for measurement early exposure to CuO nanoparticles.

Hardystonite (HT) is Zn-modified silicate bioceramics with promising results for bone tissue regeneration. However, HT possesses no obvious apatite formation. Thus, in this study we incorporated Sr and Ti into HT to prepare Sr-Ti-hardystonite (Sr-Ti-HT) nanocomposite and evaluated its in vitro bioactivity with the purpose of developing a more bioactive bone substitute material. The HT and Sr-Ti-HT were prepared by mechanical milling and subsequent heat treatment. Calcium oxide (CaO), zinc oxide (ZnO) and silicon dioxide (SiO2) (all from Merck) were mixed with molar ratio of 2:1:2. The mixture of powders mixture was then milled in a planetary ball mill for 20 h. In the milling run, the ball-to-powder weight ratio was 10:1 and the rotational speed was 200 rpm. After synthesis of HT, 3% nanotitanium dioxide (TiO2, Degussa) and 3% strontium carbonate (SrCO3, Merck) were added to HT and then the mixture was ball milled and calcined at 1150°C for 6 h. Simultaneous thermal analysis (STA), X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Fourier transform infra-red spectroscopy (FT-IR) performed to characterize the powders. XRD and FT-IR confirmed the crystal phase and silicate structure of HT and TEM images demonstrated the nanostructure of powders. Further, Sr-Ti-HT induced apatite formation and showed a higher human mesenchymal stem cell (hMSCs) adhesion and proliferation compared to HT. Our study revealed that Sr-Ti-HT with a nanostructured crystal structure of 50 nm, can be prepared by mechanical activation to use as biomaterials for orthopedic applications.

Abdominal adhesions are one of the most important problems, occurring after intra-abdominal surgery in more than 90% of cases. This condition is the leading cause of bowel obstruction, infertility, and abdominal/pelvic pain. Gold nanoparticles (GNPs) have been shown to be non-toxic and exhibit anti-inflammatory, anti-angiogenic and antioxidant activities. The purpose of this study was to determine the effect of intraperitoneal lavage with GNP solutions on the development of postoperative peritoneal adhesion (PPA). In the current experimental study, thirty-five male Wistar rats were randomly assigned to seven groups of five rats. After a standardized peritoneal injury, GNP solutions in different concentrations (1, 2.5, 5, 10, 50 and 100 ng/ml) were locally administered through nebulization; normal saline (NS) was administered to the control group. Two weeks later, the rats were sacrificed and cecum and peritoneal samples were harvested for histopathological assessment. Blood samples were obtained to determine serum concentrations of inflammatory biomarkers including tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β) and vascular endothelial growth factor (VEGF). The rats treated with GNPs had significantly lower microscopic and macroscopic peritoneal adhesion scores, compared to the control group (P<0.05). Score 5 of macroscopic adhesions was reported in all the rats of the control group, unlike the GNP groups. Furthermore, microscopic adhesions were reported with all rats in the control group, unlike the GNP groups (reported in 0 out of 5 rats in all GNP groups). In addition, serum levels of IL-1β, TNF-α and VEGF underwent no significant changes. Compared to the control group, GNPs decreased the severity of peritoneal adhesions, although they did not alter TNF-α, IL-1β or VEGF serum levels.

The development of reliable and ecofriendly process for the synthesis of nano-metals is an important aspect in the field of nanotechnology. Nano-metals are a special group of materials with broad area of applications. In this study, extracellular synthesis of silver nanoparticles (SNPs) performed by use of the gram positive soil Streptomycetes. Streptomycetes isolated from rice fields of Guilan Province, Iran (5 isolates). Initial characterization of SNPs was performed by visual change color. To determine the bacterium taxonomical identity, its colonies characterized morphologically by use of scanning electron microscope. The PCR molecular analysis of active isolate represented its identity partially. In this regard, 16S rDNA of isolate G was amplified using universal bacterial primers FD1 and RP2. The PCR products were purified and sequenced. Sequence analysis of 16S rDNA was then conducted using NCBI GenBank database using BLAST. Also SNPs were characterized by, transmission electron microscopy (TEM) and X-ray diffraction spectroscopy (XRD). From all 5 collected Streptomyces somaliensis isolates, isolate G showed highest extracellular synthesis of SNPs via in vitro. SNPs were formed immediately by the addition of (AgNO3) solution (1 mM). UV-visible spectrophotometry for measuring surface plasmon resonance showed a single absorption peak at 450 nm, which confirmed the presence of SNPs. TEM revealed the extracellular formation of spherical silver nanoparticles in the size range of 5-35 nm. The biological approach for the synthesis of metal nanoparticles offers an environmentally benign alternative to the traditional chemical and physical synthesis methods. So, a simple, environmentally friendly and cost-effective method has been developed to synthesize AgNPs using Streptomycetes.

The aim of this work was to prepare and characterize magnetic nanoparticles (MNPs) as theranostic system to act simultaneously as drug carrier and MRI contrast agent. Chitosan-coated MNPs (CMNPs) were prepared and loaded with silymarin. Silymarin-loaded CMNPs were characterized with various techniques and their potential as MRI contrast agent was also evaluated. The chitosan-coated MNPs were prepared by coprecipitation method and were loaded with silymarin. The synthesized nanoparticles were characterized by various techniques including SEM, TEM, X‐ray diffraction (XRD), FTIR and vibrating sample magnetometer (VSM). In vitro drug release of silymarin was evaluated at 37 ˚C at pH 5.3 and 7.4. Then, their proton relaxivity was evaluated to study the potential of CMNPs as MRI contrast agent in terms of r1 and r2. Silymarin-loaded CMNPs were successfully prepared and characterized by FTIR and XRD techniques. VSM analysis revealed superparamagnetic properties of CMNPs. The release study showed that the maximum drug release accessible for CMNPs in pH=5.3 was higher than pH=7.4. Finally, the r2/r1 value of CMNPs was found to be close to 20 indicating that CMNPs has a strong efficiency as T2 contrast agents for MRI imaging. The findings demonstrated the potential of CMNPs as efficient MRI contrast agent as well as silymarin drug delivery.