Fluorescence Characterization of Gold Modified Liposomes with Antisense N-myc DNA Bound to the Magnetisable Particles with Encapsulated Anticancer Drugs (Doxorubicin, Ellipticine and Etoposide)

Liposome-based drug delivery systems hold great potential for cancer therapy. The aim of this study was to design a nanodevice for targeted anchoring of liposomes (with and without cholesterol) with encapsulated anticancer drugs and antisense N-myc gene oligonucleotide attached to its surface. To meet this main aim, liposomes with encapsulated doxorubicin, ellipticine and etoposide were prepared. They were further characterized by measuring their fluorescence intensity, whereas the encapsulation efficiency was estimated to be 16%. The hybridization process of individual oligonucleotides forming the nanoconstruct was investigated spectrophotometrically and electrochemically. The concentrations of ellipticine, doxorubicin and etoposide attached to the nanoconstruct in gold nanoparticle-modified liposomes were found to be 14, 5 and 2 µg·mL⁻¹, respectively. The study succeeded in demonstrating that liposomes are suitable for the transport of anticancer drugs and the antisense oligonucleotide, which can block the expression of the N-myc gene.

Diagnosis of porcine circovirus type 2 infection with a combination of immunomagnetic beads, single-domain antibody, and fluorescent quantum dot probes

The use of a specific antibody conjugated with nanobeads, forming immunomagnetic nanobeads (IMNBs), has been demonstrated to be useful for the capture and detection of viruses. In this study, IMNBs functionalized with a single-domain antibody against the capsid protein (Cap) of porcine circovirus type 2 (PCV2), hereafter denoted as psdAb, were evaluated and used to capture PCV2. Quantum dots (QDs) conjugated with psdAb were used as a fluorescence probe to visualize PCV2 captured by IMNBs. The specificity and sensitivity of this method were further evaluated using common pathogens of pig viral disease and PCV2. To assess its practicality, clinical samples were tested in this study. The results showed that 2.57 ± 0.13 mg Cap or 0.97 ± 0.064 × 10(6) copies of PCV2 particles could be captured by 1 mg of IMNBs in 30 min. This suggests that the IMNBs have the ability to efficiently capture PCV2 with good specificity, as there was no cross-reaction with other pathogens, and with strong sensitivity, with a detection limit as low as 10(3) copies/ml of PCV2 particles. Moreover, PCV2 in inguinal lymph node, lung, spleen, serum, and fecal samples was successfully detected by IMNBs. The results demonstrate that this method is promising for the rapid and effective detection of PCV2 in complex clinical samples.

Microchip capillary electrophoresis: quantum dots and paramagnetic particles for bacteria immunoseparation: rapid superparamagnetic-beads-based automated immunoseparation of Zn-Proteins from Staphylococcus aureus with nanogram yield

The emergence of drug-resistant bacteria and new or changing infectious pathogens is an important public health problem as well as a serious socioeconomic concern. Immunomagnetic separation-based methods create new possibilities for rapidly recognizing many of these pathogens. Nanomaterial-based techniques including fluorescent labeling by quantum dots as well as immunoextraction by magnetic particles are excellent tools for such purposes. Moreover, the combination with capillary electrophoresis in miniaturized microchip arrangement brings numerous benefits such as fast and rapid analysis, low sample consumption, very sensitive electrochemical and fluorescent detection, portable miniaturized instrumentation, and rapid and inexpensive device fabrication. Here the use of superparamagnetic particle-based fully automated instrumentation to isolate pathogen Staphylococcus aureus and its Zn(II)-containing proteins (Zn-proteins) is reported using a robotic pipetting system speeding up the sample preparation and enabling to analyze 48 real samples within 6 h. Cell lysis and Zn-protein extractions were obtained from a minimum of 100 cells with the sufficient yield for SDS-PAGE (several tens ng of proteins).

Integrated chip electrophoresis and magnetic particle isolation used for detection of hepatitis B virus oligonucleotides

Rapid and sensitive detection is a key step in the effective and early response to the global hazard of various viral diseases. In this study, an integrated isolation of hepatitis B virus (HBV)-specific DNA fragment by magnetic nanoparticles (MNPs) and its immediate analysis by microchip CGE was performed. Microfluidic CE chip was used to accommodate the complete process of viral DNA isolation by MNPs including hybridization and thermal denaturation followed by CE separation. Beforehand, calibration curves of HBV fragments were constructed. For isolation by MNPs, specific streptavidin-biotin interaction was used to bind complementary HBV fragment to magnetic particles. After analysis of isolated HBV by regular MNPs method, innovative approach was performed. The commercial CE chip (Bio-rad) was successfully used to execute HBV fragment isolation. Detection using LIF with detection limit of 1 ng/mL was accomplished.