Photo-immobilization of biological components on gold-coated chips for measurements using surface plasmon resonance (SPR) and a quartz crystal microbalance (QCM)

Synthesis and Characterization of Polyethylene Glycol-Grafted Photoreactive Polyethylene Glycols for Antibiofouling Applications

Notably, antibiofouling is an important and predominant technique adopted to improve the surfaces of biomaterials. In this study, polyethylene glycol-grafted polyethylene glycols bearing azidophenyl groups were synthesized and immobilized on polystyrene surfaces via photoirradiation. The prepared polymers were found to be highly soluble in water, and photoimmobilization with fluorescent proteins was confirmed based on micropatterning using a photomask. These polymers suppressed nonspecific interactions between proteins and cells on the substrate. Considering that photoimmobilization can be adopted for the covalent bond modification of various surfaces, the developed water-soluble and highly antibiofouling polymers appear to be useful in biomaterial preparation.

Rapid and quantitative detection of multiple antibodies against SARS-CoV-2 mutant proteins by photo-immobilized microarray

A rapid automatic quantitative diagnostic system for multiple SARS-CoV-2 mutant protein-specific antibodies was developed using a microarray with photoreactive polymers. Two types of photoreactive polymers, phenylazide and polyoxyethylene, were prepared. The polymers were coated on a plastic plate. Aqueous solutions of mutant virus proteins were microspotted on the coated plate and immobilized by photoirradiation. Virus-specific IgG in the serum or blood was automatically assayed using an instrument that we developed for pipetting, reagent stirring, and washing. The results highly correlated with those of the conventional enzyme-linked immunoassay or immunochromatography. This system was successfully used to test the sera or blood from the patients recovered from the infection and the vaccinated individuals. The recovered individuals had antibodies against the nucleoprotein, in contrast to the vaccinated individuals. The amount of antibodies produced decreased with an increase in virus mutation. Blood collected from the fingertip (5 μL) and a test period of 8 min were sufficient conditions for conducting multiple antibody assays. We believe that our system would facilitate rapid and quantitative automatic assays and aid in the diagnosis of various viral infectious diseases and assessment of the immune status for clinical applications.

Novel microarrays for simultaneous serodiagnosis of multiple antiviral antibodies

We developed an automated diagnostic system for the detection of virus-specific immunoglobulin Gs (IgGs) that was based on a microarray platform. We compared efficacies of our automated system with conventional enzyme immunoassays (EIAs). Viruses were immobilized to microarrays using a radical cross-linking reaction that was induced by photo-irradiation. A new photoreactive polymer containing perfluorophenyl azide (PFPA) and poly(ethylene glycol) methacrylate was prepared and coated on plates. Inactivated measles, rubella, mumps, Varicella-Zoster and recombinant Epstein-Barr viruse antigen were added to coated plates, and irradiated with ultraviolet light to facilitate immobilization. Virus-specific IgGs in healthy human sera were assayed using these prepared microarrays and the results obtained compared with those from conventional EIAs. We observed high correlation (0.79-0.96) in the results between the automated microarray technique and EIAs. The microarray-based assay was more rapid, involved less reagents and sample, and was easier to conduct compared with conventional EIA techniques. The automated microarray system was further improved by introducing reagent storage reservoirs inside the chamber, thereby conserving the use of expensive reagents and antibodies. We considered the microarray format to be suitable for rapid and multiple serological diagnoses of viral diseases that could be developed further for clinical applications.

Use of phage display technology for the determination of the targets for small-molecule therapeutics

IMPORTANCE OF THE FIELD

Target discovery of drug-like small-molecules contributes to our understanding of biological phenomena at the molecular level as well as elucidating the mode of action of bioactive compounds. Research in this field is of high value because, in addition to basic observations, the data can be used to directly identify molecular targets or investigate pharmacokinetic characteristics of drugs in clinical use.

AREAS COVERED IN THIS REVIEW

In addition to providing a brief overview of phage display (PD) technology, we discuss screening platforms, different types of phage libraries and the application of this method to the determination of targets for small-molecule therapeutics over the past decade.

WHAT THE READER WILL GAIN

Readers will gain an understanding of the basis of PD technology through successful examples of the use of this method for the determination of targets for small-molecule therapeutics. They will learn what kinds of small-molecules were used to identify their binding partner, what characteristics and drawbacks are present in the use of small-molecule as bait, and what kinds of approaches were introduced in order to improve the technique to overcome the limitations of conventional strategies.

TAKE HOME MESSAGE

A suitable combination of diverse technologies from various different fields can act synergistically to increase throughput and enhance the efficiency of PD technology for the determination of targets for small-molecule therapeutics. The most suitable method for successful target identification of small-molecules of interest using PD technology can often be determined by referring to past examples.

Survey of the 2009 commercial optical biosensor literature

We took a different approach to reviewing the commercial biosensor literature this year by inviting 22 biosensor users to serve as a review committee. They set the criteria for what to expect in a publication and ultimately decided to use a pass/fail system for selecting which papers to include in this year's reference list. Of the 1514 publications in 2009 that reported using commercially available optical biosensor technology, only 20% passed their cutoff. The most common criticism the reviewers had with the literature was that "the biosensor experiments could have been done better." They selected 10 papers to highlight good experimental technique, data presentation, and unique applications of the technology. This communal review process was educational for everyone involved and one we will not soon forget.

Immobilisation of bifenthrin for termite control

BACKGROUND

Termites are worldwide pests causing considerable damage to agriculture, forestry and buildings. While various approaches have been tried to eliminate termite populations, the relevant toxicants are associated with certain risks to the environment and human health.

RESULTS

In this study, to combine the merits of effective chemical control by bifenthrin and a drug photoimmobilisation technique, silk fibroin was used as a carrier to embed bifenthrin, which was then photoactively immobilised by ultraviolet treatment on the surface of wood (cellulose). The immobilised bifenthrin embedded in the photoactive silk fibroin was characterised by Fourier transform infrared spectroscopy (FTIR), ultraviolet absorption spectroscopy (UV), fluorescence measurement and CHN analysis. The surface structures and biological activity were examined by scanning electron microscopy (SEM), atomic force microscopy (AFM), electron spectroscopy for chemical analysis (ESCA) and bioassays respectively.

CONCLUSIONS

The results indicate that the embedded and immobilised bifenthrin has been very well protected from free release and has a long-term stability allowing slow release with a high efficiency against termites at a low dose of 1.25 µg cm(-2). This study provides a novel and environmentally benign technique for termite control by photoimmobilising silk-fibroin-embedded bifenthrin on the surface of materials that are otherwise easily attacked by termites.