Virus-based surface patterning of biological molecules, probes, and inorganic materials

Strategies for Surface Immobilization of Whole Bacteriophages: A Review

Bacteriophage immobilization is a key unit operation in emerging biotechnologies, enabling new possibilities for biodetection of pathogenic microbes at low concentration, production of materials with novel antimicrobial properties, and fundamental research on bacteriophages themselves. Wild type bacteriophages exhibit extreme binding specificity for a single species, and often for a particular subspecies, of bacteria. Since their specificity originates in epitope recognition by capsid proteins, which can be altered by chemical or genetic modification, their binding specificity may also be redirected toward arbitrary substrates and/or a variety of analytes in addition to bacteria. The immobilization of bacteriophages on planar and particulate substrates is thus an area of active and increasing scientific interest. This review assembles the knowledge gained so far in the immobilization of whole phage particles, summarizing the main chemistries, and presenting the current state-of-the-art both for an audience well-versed in bioconjugation methods as well as for those who are new to the field.

Is Viral Vector Gene Delivery More Effective Using Biomaterials?

Gene delivery has been extensively investigated for introducing foreign genetic material into cells to promote expression of therapeutic proteins or to silence relevant genes. This approach can regulate genetic or epigenetic disorders, offering an attractive alternative to pharmacological therapy or invasive protein delivery options. However, the exciting potential of viral gene therapy has yet to be fully realized, with a number of clinical trials failing to deliver optimal therapeutic outcomes. Reasons for this include difficulty in achieving localized delivery, and subsequently lower efficacy at the target site, as well as poor or inconsistent transduction efficiency. Thus, ongoing efforts are focused on improving local viral delivery and enhancing its efficiency. Recently, biomaterials have been exploited as an option for more controlled, targeted and programmable gene delivery. There is a growing body of literature demonstrating the efficacy of biomaterials and their potential advantages over other delivery strategies. This review explores current limitations of gene delivery and the progress of biomaterial-mediated gene delivery. The combination of biomaterials and gene vectors holds the potential to surmount major challenges, including the uncontrolled release of viral vectors with random delivery duration, poorly localized viral delivery with associated off-target effects, limited viral tropism, and immune safety concerns.

Isolation and separation of Listeria monocytogenes using bacteriophage P100-modified magnetic particles

A bacteriophage-assisted magnetic separation method was developed for the isolation of Listeria monocytogenes from complex food matrices. The aim of this study is to understand the effect of phage immobilization methods and the magnetic particle sizes on the phage coupling and infectivity retention of the magnetic particles. In this study, bacteriophage P100-modified magnetic particles (PMMPs) were developed for the separation of L. monocytogenes from food matrices. Three sizes of magnetic particles (MP) (150 nm, 500 nm, and 1 μm) were used for phage immobilization via chemical and physical methods. The coupling ratio of phage was investigated, and the performance of each PMMP complex was evaluated by their L. monocytogenes capture efficiency. When compared to the chemical immobilization method, the physically immobilized PMMP complex achieved a higher capture efficiency initially, with excellent selectivity towards target bacteria. The PMMPs were further tested for selective isolation of L. monocytogenes using real food samples such as ground beef and whole milk.

Charge-Directed Immobilization of Bacteriophage on Nanostructured Electrode for Whole-Cell Electrochemical Biosensors

A new type of carbon nanotube (CNT)-based impedimetric biosensing method has been developed for rapid and selective detection of live bacterial cells. A proof-of-concept study was conducted using T2 bacteriophage-based biosensors for electrochemical detection of Escherichia coli B. The T2 bacteriophage (virus) served as the biorecognition element, which was immobilized on polyethylenimine (PEI)-functionalized carbon nanotube transducer on glassy carbon electrode. Charge-directed, orientated immobilization of bacteriophage particles on carbon nanotubes was achieved through covalent linkage of phage capsid onto the carbon nanotubes. The presence of the immobilized phage on carbon nanotube-modified electrode was confirmed by fluorescence microscopy. Electrochemical impedance spectroscopy (EIS) was used to monitor the changes in the interfacial impedance due to the binding of E. coli B to T2 phage on the CNT-modified electrode. The detection was highly selective toward the B strain of E. coli as no signal was observed for the nonhost K strain of E. coli. The present achievable detection limit of the biosensor is 10³ CFU/mL.