Methotrexate loaded in alginate beads for controlled drug release against breast cancer.

Methotrexate (MTX), as a folate antagonist is used for breast cancer chemotherapy, but its application due to the adverse side effects was limited. In this study, MTX were encapsulated in magnetic alginate beads coated with glutaraldehyde to control its release in order to reduce the side effects and improve its stability. The complex was characterized by physicochemical studies. The encapsulation efficiency was 75 % and the complex showed acceptable controlled release behavior. The cell cytotoxicity assessed using methylthiazol tetrazolium (MTT) method showed that magnetic alginate beads-MTX, in lower dosage has higher anticancer effect compared to the free MTX. The real-time polymerase chain reaction (PCR) was used to evaluate apoptotic factors Bcl2 associated X gene (Bax), B-cell lymphoma 2 (Bcl-2), and neuroinflammatory marker tumor necrosis factor-alpha (TNF-α) genes expression level on the treated cells. The findings demonstrated the significant increase of expression of Bax and a significant decrease in the expressions of Bcl-2 and TNF-α in Michigan cancer foundation-7 (MCF-7) cells. These results indicated that the developed drug can overcome the side effects of MTX and offer a controlled drug release for a sustained period with the long-term treatment of breast cancer.

Design of highly sensitive nano-biosensor for diagnosis of hydatid cyst based on gold nanoparticles.

Cystic echinococcosis, a zoonotic parasitic infection, is a major public health and economic concern, with worldwide distribution. The development of sensitive diagnostic methods for hydatid disease is important. We designed a highly sensitive nano-biosensor for the diagnosis of hydatid cyst based on gold nanoparticles (AuNPs). AuNPs were synthesized. Echinococcus granulosus antigen was coated on the ELISA microwells. Then, the E. granulosus IgG antibody was added to the microwells. After incubation and washing, the Ag-Ab complex was incubated with a human IgG HRP​-conjugated antibody. Then, the synthesized AuNPs and tetramethylbenzidine (TMB), as a chromogenic substrate of HRP, were added to the reaction. Finally, the absorption rate was measured by spectrophotometry. The results showed that the enzyme peroxide and TMB change the color of the reaction from red to yellow by oxidizing AuNPs. The sensitivity and specificity of the designed method were investigated. The linear equation and regeneration of nanobiosensor designed for red color Y = 0.0312X + 0.649, R2 9962 and for yellow color Y = 0.013X + 0.398, R2 9851 were determined. The limit of detection of the designed nanobiosensor was 0.001 µg mL-1. The results confirmed that the designed nanobiosensor was completely specific for the detection of E. granulosus antibody.

A fluorescence Nano-biosensors immobilization on Iron (MNPs) and gold (AuNPs) nanoparticles for detection of Shigella spp.

The highly sensitive and specificity detection are very important in diagnosis of foodborne pathogens and prevention of spread diseases. Therefore, in the present study, a highly sensitive fluorescence Nano-biosensors was designed for detection of Shigella species. For achieved this purpose, DNA probes and gold nanoparticles (AuNPs) were designed and synthesized, respectively. Then, two DNA probes as signal reporter were immobilized on surface of AuNPs. On the other hand, Iron nanoparticles (MNPs) were synthesized and modified with SMCC (Sulfosuccinimidyl 4-Nmaleimidomethyl cyclohexane-1- carboxylate). The 3th DNA probe was immobilized on surface of MNPs for separation of target DNA. The MNP-DNA probe and DNA probe-AuNP-fluorescence DNA probe were added to target DNA. The MNP- DNA probe-target DNA-DNA probe-AuNP-fluorescence DNA probe complex was isolated by a magnet. The fluorescence DNA probe was released on surface of AuNPs and the fluorescence intensity was read by fluorescence spectrophotometry. Sensitivity and specificity of designed Nano-biosensor was determined. The results showed that the fluorescence intensity was increased with increasing of target DNA concentration. Linear related between target DNA and fluorescence intensity was observed in 2.3 × 102 up to 2.3 × 107 CFU mL-1. The linear equation and regression were Y = 1.8 X + 23.4 and R2 0.9953. Limit of detection (LOD) were determined 90 CFUmL-1. The specificity of Nano-biosensor in present of other bacteria was confirmed.

Folic acid functionalized nanoparticles as pharmaceutical carriers in drug delivery systems.

Conventional chemotherapeutic approaches in cancer therapy such as surgery, chemotherapy, and radiotherapy have several disadvantages due to their nontargeted distributions in the whole body. On the other hand, nanoparticles (NPs) based therapies are remarkably progressing to solve several limitations of conventional drug delivery systems (DDSs) including nonspecific biodistribution and targeting, poor water solubility, weak bioavailability and biodegradability, low pharmacokinetic properties, and so forth. The enhanced permeability and retention effect escape from P-glycoprotein trap in cancer cells as a passive targeting mechanism, and active targeting strategies are also other most important advantages of NPs in cancer diagnosis and therapy. Folic acid (FA) is one of the biologic molecules which has been targeted overexpressed-folic acid receptor (FR) on the surface of cancer cells. Therefore, conjugation of FA to NPs most easily enhances the FR-mediated targeting delivery of therapeutic agents. Here, the recent works in FA which have been decorated NPs-based DDSs are discussed and cancer therapy potency of these NPs in clinical trials are presented.

Bio-barcode technology for detection of Staphylococcus aureus protein A based on gold and iron nanoparticles.

S. aureus is one of important causes of disease, food poisoning in humans and animals. The generally methods for detection of S. aureus is time consuming. Therefore, a new method is necessary for rapid, sensitive and specific diagnosis of S. aureus. In the present study, two probes and a Bio-barcode DNA were designed for detection of S. aureus (Protein A). Firstly, magnetic nanoparticle (MNPs) and gold nanoparticle (AuNPs) were synthesized at 80 °C and 100 °C, respectively. The AuNPs and the MNPs were functionalized with probe1, Bio-barcode DNA and probe2, respectively. Target DNA was added into the nanomaterial's system containing bio-barcode DNA-AuNPs-probe1 and probe2-MNPs to formed bio-barcode DNA-AuNPs-probe1-target DNA-probe2-MNPs complex. The bio-barcode DNA-AuNPs-probe1-target DNA-probe2-MNPs complex was separated with magnetic field. Finally, the bio-barcode DNA was released from surface of complex using DTT (0.8 M) and there was isolated of nanoparticles by magnetic field and centrifuge. The fluorescence intensity of bio-barcode DNA was measured in different concentrations of S. aureus (101 to 108 CFU mL-1) by fluorescence spectrophotometry. The results showed that standard curve was linearly from 102 to 107 CFU mL-1. Limit of detection of bio-barcode assay for both PBS and real samples was 86 CFU mL-1.

A human protein atlas for normal and cancer tissues based on antibody proteomics.

Antibody-based proteomics provides a powerful approach for the functional study of the human proteome involving the systematic generation of protein-specific affinity reagents. We used this strategy to construct a comprehensive, antibody-based protein atlas for expression and localization profiles in 48 normal human tissues and 20 different cancers. Here we report a new publicly available database containing, in the first version, approximately 400,000 high resolution images corresponding to more than 700 antibodies toward human proteins. Each image has been annotated by a certified pathologist to provide a knowledge base for functional studies and to allow queries about protein profiles in normal and disease tissues. Our results suggest it should be possible to extend this analysis to the majority of all human proteins thus providing a valuable tool for medical and biological research.

Multiple-primer DNA sequencing method.

A multiple-primer DNA sequencing approach suitable for genotyping, detection and identification of microorganisms and viruses has been developed. In this new method two or more sequencing primers, combined in a pool, are added to a DNA sample of interest. The oligonucleotide that hybridizes to the DNA sample will function as a primer during the subsequent DNA sequencing procedure. This strategy is suited for selective detection and genotyping of relevant microorganisms and samples harboring different DNA targets such as multiple variant/infected samples as well as unspecific amplification products. This method is used here in a model system for detection and typing of high-risk oncogenic human papilloma viruses (HPVs) in samples containing multiple infections/variants or unspecific amplification products. Type-specific sequencing primers were designed for four of the most oncogenic (high-risk) HPV types (HPV-16, HPV-18, HPV-33, and HPV-45). The primers were combined and added to a sample containing a mixture of one high-risk (16, 18, 33, or 45) and one or two low-risk types. The DNA samples were sequenced by the Pyrosequencing technology and the Sanger dideoxy sequencing method. Correct genotyping was achieved in all tested combinations. This multiple-sequencing primer approach also improved the sequence data quality for samples containing unspecific amplification products. The new strategy is highly suitable for diagnostic typing of relevant species/genotypes of microorganisms.