Immobilization of HIV-1 TAT peptide on gold nanoparticles: A feasible approach for siRNA delivery.

RNA interference is one of the prosperous approaches for cancer treatment. However, small interfering RNA (siRNA) delivery to cancer cells has been faced with various challenges restricting their clinical application over the decades. Since ROR1 is an onco-embryonic gene overexpressed in many malignancies, suppression of ROR1 by siRNA can potentially fight cancer. Herein, a delivery system for ROR1 siRNA based on HIV-1 TAT peptide-capped gold nanoparticles (GNPs) was developed to treat breast cancer. Besides, we introduced a new feasible method for conjugating the peptide to the nanoparticles. Since the GNPs have high affinity to the sulfur, the findings demonstrated the peptide successfully conjugated to the nanoparticles via Au-S bonds. As positively charged nanoparticles showed high cellular uptake, we could use a low concentration of nanoparticles led to high efficient gene transfection with negligible cytotoxicity that was confirmed by flow cytometry, confocal microscopy, gel retardation, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Following transfection, downregulation of ROR1 and its targeted gene, CCND1, induced apoptosis in cancer cells. In conclusion, the reported capped GNPs could be potentially utilized for delivering negatively charged therapeutic agents in particular genes.

Preparation and optimization of N-trimethyl-O-carboxymethyl chitosan nanoparticles for delivery of low-molecular-weight heparin.

The aim of this study was preparation, optimization and in vitro characterization of nanoparticles composed of 6-[O-carboxymethyl]-[N,N,N-trimethyl] (TMCMC) for oral delivery of low-molecular-weight heparin. The chitosan derivative was synthesized. Nanoparticles were prepared using the polyelectrolyte complexation method. Box-Behnken response surface experimental design methodology was used for optimization of nanoparticles. The morphology of nanoparticles was studied using transmission electron microscopy. In vitro release of enoxaparin from nanoparticles was determined under simulated intestinal fluid. The cytotoxicity of nanoparticles on a Caco-2 cell line was determined, and finally the transport of prepared nanoparticles across Caco-2 cell monolayer was defined. Optimized nanoparticles with proper physico-chemical properties were obtained. The size, zeta potential, poly-dispersity index, entrapment efficiency and loading efficiency of nanoparticles were reported as 235 ± 24.3 nm, +18.6 ± 2.57 mV, 0.230 ± 0.03, 76.4 ± 5.43% and 12.6 ± 1.37%, respectively. Morphological studies revealed spherical nanoparticles with no sign of aggregation. In vitro release studies demonstrated that 93.6 ± 1.17% of enoxaparin released from nanoparticles after 600 min of incubation. MTT cell cytotoxicity studies showed no cytotoxicity at 3 h post-incubation, while the study demonstrated concentration-dependent cytotoxicity after 24 h of exposure. The obtained data had shown that the nanoparticles prepared from trimethylcarboxymethyl chitosan may be considered as a good candidate for oral delivery of enoxaparin.

Stealth Nanogels of Histinylated Poly Ethyleneimine for Sustained Delivery of Methotrexate in Collagen-Induced Arthritis Model.

PURPOSE: The study aimed to illustrate application of polycation Stealth nanogels for sustained delivery of methotrexate (MTX) in collagen induced arthritis (CIA) model in C57Bl/6 mice. METHODS: Nanogel synthesis involves metal ion coordinated self-assembly of PEGylated poly ethyleneimine (L-histidine substituted), chemical crosslinking and subsequent removal of the coordinated metal. The nanogels were characterized by TEM and DLS-zeta potential. Comparative efficacy and pharmacokinetics of the i.v. administred MTX-loaded nanogels were investigated in the CIA model. Inflammation site passive accumulation of the fluorophore-labeled nanogels was tested using in-vivo imaging of mice paw received unilateral injection of lipopolysaccharide. RESULTS: Uniform nanogels (sizes ~40 nm by TEM) were loaded with MTX (entrapment efficiency = 62% and drug loading = 54% at the MTX feeding ratio of 0.3 relative to total molar concentration of the polymer amines). The nanogels exhibited neutral surface charge and an acceptable biocompatibility in terms of albumin aggregation, hemolysis, erythrocyte aggregation and cytotoxicity. Single dose pharmacokinetics of the MTX-loaded nanogels, unlike free drug, showed a sustained plasma profile. When arthritis established as confirmed by histopathology, a remarkable decline of paw swelling and clinical scores was observed. Fluorescence intensity of the nanogels was enhanced about 2.7 folds at the inflamed than control normal ankle. CONCLUSION: Sustained delivery of MTX and preferential accumulation of the nanogels in inflamed paw might explain the superior clinical outcome of the MTX-loaded nanogels.

Water-compatible molecularly imprinted polymer as a sorbent for the selective extraction and purification of adefovir from human serum and urine.

A molecularly imprinted polymer has been synthesized to specifically extract adefovir, an antiviral drug, from serum and urine by dispersive solid-phase extraction before high-performance liquid chromatography with UV analysis. The imprinted polymers were prepared by bulk polymerization by a noncovalent imprinting method that involved the use of adefovir (template molecule) and functional monomer (methacrylic acid) complex prior to polymerization, ethylene glycol dimethacrylate as cross-linker, and chloroform as porogen. Molecular recognition properties, binding capacity, and selectivity of the molecularly imprinted polymers were evaluated and the results show that the obtained polymers have high specific retention and enrichment for adefovir in aqueous medium. The new imprinted polymer was utilized as a molecular sorbent for the separation of adefovir from human serum and urine. The serum and urine extraction of adefovir by the molecularly imprinted polymer followed by high-performance liquid chromatography showed a linear calibration curve in the range of 20-100 µg/L with excellent precisions (2.5 and 2.8% for 50 µg/L), respectively. The limit of detection and limit of quantization were determined in serum (7.62 and 15.1 µg/L), and urine (5.45 and 16 µg/L). The recoveries for serum and urine samples were found to be 88.2-93.5 and 84.3-90.2%, respectively.

Assessment of the vaccine industry in Iran in context of accession to WTO: a survey study.

BACKGROUND: The vaccine industry is one of the most important health-related industries. It can be affected by accession to the World Trade Organization (WTO) because of probable dramatic changes in the business environment. Iran has already initiated accession negotiations. PURPOSE OF THE STUDY: In this paper, we investigate the position of, challenges to, and opportunities for vaccine manufacturing in Iran with regard to accession to the WTO. METHODS: This is a qualitative and cross sectional study. To collect information, we designed a questionnaire and interviewed some of the vaccine industry's key opinion leaders in Iran. Before the interviews were conducted, the questionnaires were sent to these individuals by email. RESULTS: According to the interviewees, the country's main challenges with regard to accession to the WTO are the lack of firm internal intellectual property (IP) rules, not being recognized as pre-qualified by the World Health Organization (WHO), the use of old equipment, and a lack of cooperation with global vaccine companies. MAJOR CONCLUSIONS: Iran's local vaccine industry, with a long history and international reputation that could be used as an advantage, is faced with several challenges, such as problems with keeping up with Current Good Manufacturing Practice (cGMP), a lack of adequate and meaningful investment in research and development (R&D), and limitations on private sector participation in the production of vaccines.Gradual privatization of the industry, improved international relations, utilization of the R&D power of small hi-tech companies, consistent education of human resources, and modernization of infrastructures and equipment are among the suggested solutions.

Development and validation of a stability-indicating method for the quantitation of Paclitaxel in pharmaceutical dosage forms.

A simple, rapid stability-indicating isocratic assay has been developed and validated for the determination of Paclitaxel (PTX) in commercial injection formulations. The assay is performed using a Nucleosil RP-18 (5 microm, 250 x 4.0 mm i.d) column protected by a Nucleosil C(18) precolumn (5 microm, 4.0 x 4.0 mm i.d.) with a mobile phase of methanol-water (80:20) and UV detection at 230 nm. The method was found to be specific for PTX in the presence of degradation products with an overall analytical run time of ~ 9 min. Accuracy reported as % bias was found to be 0.1-2.5% bias for all samples tested. Intra-assay precision (repeatability) was found to be 0.22-2.65% RSD, while inter-day precision (intermediate precision) was found to be 1.0-3.0% RSD for the samples studied. The calibration curve was found to be linear with the equation y = 29.78x + 7.65, and a linear regression coefficient of 0.9994 over the concentration range 0.05-20 microg/mL. The limits of quantitation and detection were 0.05 and 0.02 microg/mL, respectively. Taxol (30 mg/5 mL), a commercially available dosage form of PTX, was assayed and 100.6-103.6% of the label claim was recovered.

Determination of diclofenac on a dysprosium nanowire- modified carbon paste electrode accomplished in a flow injection system by advanced filtering.

A new detection technique called Fast Fourier Transform Square-Wave Voltammetry (FFT SWV) is based on measurements of electrode admittance as a function of potential. The response of the detector (microelectrode), which is generated by a redox processes, is fast, which makes the method suitable for most applications involving flowing electrolytes. The carbon paste electrode was modified by nanostructures to improve sensitivity. Synthesized dysprosium nanowires provide a more effective nanotube-like surface [1-4] so they are good candidates for use as a modifier for electrochemical reactions. The redox properties of diclofenac were used for its determination in human serum and urine samples. The support electrolyte that provided a more defined and intense peak current for diclofenac determination was a 0.05 mol L(-1) acetate buffer pH = 4.0. The drug presented an irreversible oxidation peak at 850 mV vs. Ag/AgCl on a modified nanowire carbon paste electrode which produced high current and reduced the oxidation potential by about 100 mV. Furthermore, the signal-to-noise ratio was significantly increased by application of a discrete Fast Fourier Transform (FFT) method, background subtraction and two-dimensional integration of the electrode response over a selected potential range and time window. To obtain the much sensivity the effective parameters such as frequency, amplitude and pH was optimized. As a result, C(DL) of 2.0 × 10(-9) M and an LOQ of 5.0 × 10(-9) M were found for the determination for diclofenac. A good recovery was obtained for assay spiked urine samples and a good quantification of diclofenac was achieved in a commercial formulation.

Chitosan and thiolated chitosan: Novel therapeutic approach for preventing corneal haze after chemical injuries.

Corneal haze, commonly caused by deep physical and chemical injuries, can greatly impair vision. Growth factors facilitate fibroblast proliferation and differentiation, which leads to haze intensity. In this study, the potential effect of chitosan (CS) and thiolated-chitosan (TCS) nanoparticles and solutions on inhibition of fibroblast proliferation, fibroblast to myofibroblast differentiation, neovascularization, extracellular matrix (ECM) deposition, and pro-fibrotic cytokine expression was examined. Transforming growth factor beta-1 (TGFß1) was induced by interleukin-6 (IL6) in human corneal fibroblasts and expression levels of TGFß1, Platelet-derived growth factor (PDGF), α-smooth muscle actins (α-SMA), collagen type I (Col I), fibronectin (Fn) and vascular endothelial growth factor (VEGF) were quantified using qRT-PCR. To assess wound-healing capacity, TCS-treated mice were examined for α-SMA positive cells, collagen deposition, inflammatory cells and neovascularization through pathological immunohistochemistry. The results revealed that CS and TCS could down-regulate the expression levels of TGFß1 and PDGF comparable to that of TGFß1 knockdown experiment. However, down-regulation of TGFß1 was not regulated through miR29b induction. Neovascularization along with α-SMA and ECM deposition were significantly diminished. According to these findings, CS and TCS can be considered as potential anti-fibrotic and anti-angiogenic therapeutics. Furthermore, TCS, thiolated derivative of CS, will increase mucoadhesion of the polymer at the corneal surface which makes the polymer efficient and non-toxic therapeutic approach for corneal injuries.

Corneal chemical burn treatment through a delivery system consisting of TGF-ß1 siRNA: in vitro and in vivo.

Chemical burns are major causes of corneal blindness. Transforming growth factor beta-1 (TGFß1) plays an important role in induction of corneal inflammation-related-fibrosis leading to the blindness. Here, a topical delivery system consisting anti-fibrotic TGF-ß1 siRNA, an inflammatory suppressing gene, was designed for treatment of corneal injuries. TGF-ß1 siRNA loaded in nanoparticles (NPs) made up of polyethyleneimine polymer demonstrated high fibroblast transfection efficiency. Moreover, TGF-ß1 and PDGF genes and ECM deposition were suppressed in isolated human corneal fibroblasts. NPs inhibited proliferation and transformation of fibroblasts to myofibroblasts by S-phase arrest and α-SMA suppression in vitro, respectively. The mentioned finding was also confirmed in vivo, addressing high wound-healing potential of prepared gene delivery system which was superior to conventional betamethasone treatment. Besides, CD4+ and α-SMA antibody staining showed inhibited angiogenesis and myofibroblast accumulation in treated corneas. This study opens a new way for treating corneal fibrosis through topical siRNA delivery.

Impact of Corporate Reputation on Brand Differentiation: An Empirical Study from Iranian Pharmaceutical Companies.

The influence of company reputation or what is often referred to as corporate reputation on branding strategy and producing intangible asset for different industries has been researched in western countries, but there is a gap for the generalizability of findings to countries out of the United State and Europe. To establish the western researcher's external validity of theories in other countries and to obtain a better understanding of the influences of branding and company reputation on pharmaceutical business markets, the researchers applied this study for Iran, a country in the Middle East. The obtained results using SEM (by P.L.S. 2.0 software) showed a good relationship between value creation and brand differentiation (ß =0.360 and t-value = 3.167), between corporate communication and brand differentiation (ß = 0.022 and t-value = 3.668), and between strategic resources and brand differentiation (ß = 0.289 and t-value = 2.247). This study is a pioneering attempt in Iran to measure the impact of corporate reputation on brand differentiation strategy.

Molecular changes in obese and depressive patients are similar to neurodegenerative disorders.

Background: Neurodegenerative disorders (NDs) are categorized as multifactorial conditions with different molecular and environmental causes. Disturbance of important signaling pathways, such as energy metabolism and inflammation induced by environmental agents, is involved in the pathophysiology of NDs. It has been proposed that changes in the lifestyle and nutrition (metabolism) during mid-life could trigger and accumulate cellular and molecular damages resulting in NDs during aging. Methods: In order to test the hypothesis, we investigated the expression level of two energy metabolism-related [forkhead box O1 (FOXO1) and forkhead box O3 (FOXO3A)] and two pro-inflammatory cytokines [interleukin 1ß (IL-1ß) and IL-6] genes, using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). Furthermore, changes in the ionic concentration of three essential heavy metals [iron (Fe), copper (Cu), and zinc (Zn)] by atomic absorption spectroscopy in patients with NDs, depression, obesity, and diabetes type II, were evaluated and compared with the results of normal individuals. Results: More than half of the participants in obesity, depression, and ND groups had significant up-regulation of FOXO1 and FOXO3A, down-regulation of IL-1ß and IL-6, and higher levels of Fe and Cu in their blood. This pattern of gene expression was not repeated in diabetic patients. Conclusion: It could be concluded that individuals affected with different levels of obesity and depression have increased the risk of developing NDs later in life, probably through changes in energy metabolism, inflammatory pathways, and ionic concentrations.

National action plan for non-communicable diseases prevention and control in Iran; a response to emerging epidemic.

Emerging Non-communicable diseases burden move United Nation to call for 25% reduction by 2025 in premature mortality from non-communicable diseases (NCDs). The World Health Organization (WHO) developed global action plan for prevention and control NCDs, but the countries' contexts, priorities, and health care system might be different. Therefore, WHO expects from countries to meet national commitments to achieve the 25 by 25 goal through adapted targets and action plan. In this regards, sustainable high-level political statement plays a key role in rules and regulation support, and multi-sectoral collaborations to NCDs' prevention and control by considering the sustainable development goals and universal health coverage factors. Therefore, Iran established the national authority's structure as Iranian Non Communicable Diseases Committee (INCDC) and developed NCDs' national action plan through multi-sectoral approach and collaboration researchers and policy makers. Translation Iran's expertise could be benefit to mobilizing leadership in other countries for practical action to save the millions of peoples.

Pharmaceutical strategic purchasing requirements in Iran: Price interventions and the related effective factors.

OBJECTIVE: Pharmaceutical access for the poor is an essential factor in developing countries that can be improved through strategic purchasing. This study was conducted to identify the elements affecting price in order to enable insurance organizations to put strategic purchasing into practice. METHODS: This was a qualitative study conducted through content analysis with an inductive approach applying a five-stage framework analysis (familiarization, identifying a thematic framework, indexing, mapping, and interpretation). Data analysis was started right after transcribing each interview applying ATLAS.ti. Data were saturated after 32 semi-structured interviews by experts. These key informants were selected purposefully and through snowball sampling. FINDINGS: Findings showed that there are four main themes as Pharmaceutical Strategic Purchasing Requirements in Iran as follows essential and structural factors, international factors, economical factors, and legal factors. Moreover, totally 14 related sub-themes were extracted in this area as the main effective variables. CONCLUSION: It seems that paying adequate attention to the four present themes and 14 sub-themes affecting price can enable health system policy-makers of developing countries like Iran to make the best decisions through strategic purchasing of drugs by the main insurers in order to improve access and health in the country.

Chemically crosslinked nanogels of PEGylated poly ethyleneimine (l-histidine substituted) synthesized via metal ion coordinated self-assembly for delivery of methotrexate: Cytocompatibility, cellular delivery and antitumor activity in resistant cells.

Self-assembled nanogels were engineered by forming Zn(2+)-coordinated micellar templates of PEGylated poly ethyleneimine (PEG-g-PEI), chemical crosslinking and subsequent removal of the metal ion. Creation of stable micellar templates is a crucial step for preparing the nanogels. To this aim, imidazole moieties were introduced to the polymer by Fmoc-l-histidine using carbodiimide chemistry. It was hypothesized the nanogels loaded with methotrexate (MTX), a chemotherapeutic agent, circumvent impaired carrier activity in HepG2 cells (MTX-resistant hepatocellular carcinoma). So, the nanogels were post-loaded with MTX and characterized by (1)H-NMR, FTIR, dynamic light scattering-zeta potential, atomic force microscopy, and drug release experiments. Cellular uptake and the antitumor activity of MTX-loaded nanogels were investigated by flow cytometry and MTT assay. Discrete, spherical and uniform nanogels, with sizes about 77-83 nm and a relatively high drug loading (54 ± 4% w/w), showed a low polydispersity and neutral surface charges. The MTX-loaded nanogels, unlike empty nanogels, lowered viability of HepG2 cells; the nanogels demonstrated cell-cycle arrest and apoptosis comparably higher than MTX as free drug that was shown to be through i) cellular uptake of the nanogels by clathrin-mediated transport and ii) endosomolytic activity of the nanogels in HepG2 cells. These findings indicate the potential antitumor application of this preparation, which has to be investigated in-vivo.

Resource allocation and purchasing arrangements to improve accessibility of medicines: Evidence from Iran.

OBJECTIVE: The aim of this study was to review the current methods of pharmaceutical purchasing by Iranian insurance organizations within the World Bank conceptual framework model so as to provide applicable pharmaceutical resource allocation and purchasing (RAP) arrangements in Iran. METHODS: This qualitative study was conducted through a qualitative document analysis (QDA), applying the four-step Scott method in document selection, and conducting 20 semi-structured interviews using a triangulation method. Furthermore, the data were analyzed applying five steps framework analysis using Atlas-ti software. FINDINGS: The QDA showed that the purchasers face many structural, financing, payment, delivery and service procurement and purchasing challenges. Moreover, the findings of interviews are provided in three sections including demand-side, supply-side and price and incentive regime. CONCLUSION: Localizing RAP arrangements as a World Bank Framework in a developing country like Iran considers the following as the prerequisite for implementing strategic purchasing in pharmaceutical sector: The improvement of accessibility, subsidiary mechanisms, reimbursement of new drugs, rational use, uniform pharmacopeia, best supplier selection, reduction of induced demand and moral hazard, payment reform. It is obvious that for Iran, these customized aspects are more various and detailed than those proposed in a World Bank model for developing countries.

Optimization of tetrazolium salt assay for Pseudomonas aeruginosa biofilm using microtiter plate method.

Pseudomonas aeruginosa is one of the most important pathogenic bacteria related to biofilm infections. Due to the biofilm multi-drug resistance, methods of biofilm formation enumeration are of interest for assessment of efficient drug regimen development for biofilm inhibition or eradication. There are many different assay methods to determine the biofilm formation, using vital or non-vital dyes. The primary aim of the current study was to develop an assay using a member of tetrazolium salts family, 2,3,5-triphenyl-tetrazolium chloride (TTC), for detection of P. aeruginosa biofilm formation in 96-well microtiter plates and also a method of Minimum Biofilm Inhibitory Concentration (MBIC) determination of antibiotics against P. aeruginosa PAO1. Furthermore, the assay was optimized for TTC concentration, wavelength and period of incubation for 4 different antibiotics. The optimized condition was then compared with two other prevalent methods: the crystal violet (CV) assay and the 2,3-bis (2-methoxy-4-nitro-5-sulfophenly)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) assay. In general, the optimized TTC assay (0.5% TTC, 6h of incubation and absorbance measurement at 405nm for biofilm assay and 1% TTC, 5h of incubation and absorbance measurement at 490nm for MBIC determination) distinguished between biofilms formed by different concentrations of bacteria and also was able to detect lower amounts of biofilm formed in contrast to the other two assay methods suggesting that TTC assay is more sensitive and also less expensive than other vital staining methods.

Sequential optimization of methotrexate encapsulation in micellar nano-networks of polyethyleneimine ionomer containing redox-sensitive cross-links.

A functional polycation nanonetwork was developed for delivery of water soluble chemotherapeutic agents. The complexes of polyethyleneimine grafted methoxy polyethylene glycol (PEI-g-mPEG) and Zn(2+) were utilized as the micellar template for cross-linking with dithiodipropionic acid, followed by an acidic pH dialysis to remove the metal ion from the micellar template. The synthesis method was optimized according to pH, the molar ratio of Zn(2+), and the cross-link ratio. The atomic force microscopy showed soft, discrete, and uniform nano-networks. They were sensitive to the simulated reductive environment as determined by Ellman's assay. They showed few positive ζ potential and an average hydrodynamic diameter of 162±10 nm, which decreased to 49±11 nm upon dehydration. The ionic character of the nano-networks allowed the achievement of a higher-loading capacity of methotrexate (MTX), approximately 57% weight per weight, depending on the cross-link and the drug feed ratios. The nano-networks actively loaded with MTX presented some suitable properties, such as the hydrodynamic size of 117±16 nm, polydispersity index of 0.22, and a prolonged swelling-controlled release profile over 24 hours that boosted following reductive activation of the nanonetwork biodegradation. Unlike the PEI ionomer, the nano-networks provided an acceptable cytotoxicity profile. The drug-loaded nano-networks exhibited more specific cytotoxicity against human hepatocellular carcinoma cells if compared to free MTX at concentrations above 1 µM. The enhanced antitumor activity in vitro might be attributed to endocytic entry of MTX-loaded nano-networks that was found in the epifluorescence microscopy experiment for the fluorophore-labeled nano-networks.

Mu opioid receptor gene: new point mutations in opioid addicts.

INTRODUCTION: Association between single-nucleotide polymorphisms (SNPs) in mu opioid receptor gene and drug addiction has been shown in various studies. Here, we have evaluated the existence of polymorphisms in exon 3 of this gene in Iranian population and investigated the possible association between these mutations and opioid addiction. METHODS: 79 opioid-dependent subjects (55 males, 24 females) and 134 non-addict or control individuals (74 males, 60 females) participated in the study. Genomic DNA was extracted from volunteers' peripheral blood and exon 3 of the mu opioid receptor gene was amplified by polymerase chain reaction (PCR) whose products were then sequenced. RESULTS: Three different heterozygote polymorphisms were observed in 3 male individuals: 759T > C and 877G > A mutations were found in 2 control volunteers and 1043G > C substitution was observed in an opioid-addicted subject. Association between genotype and opioid addiction for each mutation was not statistically significant. DISCUSSION: It seems that the sample size used in our study is not enough to confirm or reject any association between 759T > C, 877G > A and 1043G > C substitutions in exon 3 of the mu opioid receptor gene and opioid addiction susceptibility in Iranian population.

Physicochemical and biological characterization of pep-1/elastin complexes.

Transdermal drug delivery of proteins is challenging because the skin acts as a natural and protective barrier. Several techniques including using the cell-penetrating peptides have been studied to increase the penetration of therapeutic proteins into and through the skin. Cell-penetrating peptides facilitate and improve the transduction of large and hydrophilic cargo molecules through plasma membrane. We have recently reported an efficient skin delivery of elastin protein in complex with a cell-penetrating peptide called Pep-1. As the biophysical characteristics of cell-penetrating peptide/protein complexes have been linked with their biological responses, in this study, we investigated biophysical properties of Pep-1/elastin complexes (ratio 10:1) stored in three temperatures (-20 °C, 4 °C and 25 °C) by photon correlation spectroscopy, circular dichroism and isothermal denaturation. We also evaluated the ability of transduction of this complex into cells and skin tissue using both fluorescence microscopy and Kodak In-Vivo FX Pro Imaging System.

Evaluation of thimerosal removal on immunogenicity of aluminum salts adjuvanted recombinant hepatitis B vaccine.

Thimerosal, which is approximately 50% mercury by weight is a preservative widely used in vaccines since the 1930's. It meets the requirements for a preservative as set forth by Pharmacopeia challenge test and has been shown to be effective against a broad spectrum of pathogens. In July 1999, the Public Health Service agencies and vaccine manufacturers agreed that thimerosal should be reduced or eliminated in vaccines as a precautionary measure but, due to the lack of appropriate alternative, it is still extensively used in multiple dose formulations of vaccines such as hepatitis-B in developing countries. In this study the effect of the removal of thimerosal in two formulations of hepatitis B vaccines containing either aluminum hydroxide or aluminum phosphate were evaluated in Balb/c mice. These formulations were administered interperitoneally and the titer of antibody was determined by ELISA technique after 28 days. The geometric mean of antibody titer (GMT), seroconversion and seroprotection rates, ED50 and relative potency of different formulations were determined. The ED50 of thimerosal-free formulations were reduced by more than 35% in both preparations. In addition, GMT of antibody titer, seroconversion and seroprotection indicated significantly higher immunogenicity for thimerosal free formulations for both aluminum phosphate and hydroxide adjuvants.