Antimicrobial assay and controlled drug release studies with novel eugenol imprinted p(HEMA)-bacterial cellulose nanocomposite, designed for biomedical applications.

In this study, a novel bio-composite material that allow sustained release of plant derived antimicrobial compound was developed for the biomedical applications to prevent the infections caused by microorganisms resistant to commercial antimicrobials agents. With this aim, bacterial cellulose (BC)-p(HEMA) nanocomposite film that imprinted with eugenol (EU) via metal chelated monomer, MAH was prepared. Firstly, characterization studies were utilized by FTIR, SEM and BET analysis. Then antimicrobial assays, drug release studies and in vitro cytotoxicity test were performed. A significant antimicrobial effect against both Gram (+) Staphylococcus aureus and Gram (-) Escherichia coli bacteria and a yeast Candida albicans were observed even in low exposure time periods. When antimicrobial effect of EU compared with commercially used agents, both antifungal and antibacterial activity of EU were found to be higher. Then, sustained drug release studies showed that approximately 55% of EU was released up to 50 h. This result proved the achievement of the molecular imprinting for an immobilization of molecules that desired to release on an area in a long-time interval. Finally, the in vitro cytotoxicity experiment performed with the mouse L929 cell line determined that the synthesized EU-imprinted BC nanocomposite was biocompatible.

Solid-Phase Optical Sensing Techniques for Sensitive Virus Detection.

Viral infections can pose a major threat to public health by causing serious illness, leading to pandemics, and burdening healthcare systems. The global spread of such infections causes disruptions to every aspect of life including business, education, and social life. Fast and accurate diagnosis of viral infections has significant implications for saving lives, preventing the spread of the diseases, and minimizing social and economic damages. Polymerase chain reaction (PCR)-based techniques are commonly used to detect viruses in the clinic. However, PCR has several drawbacks, as highlighted during the recent COVID-19 pandemic, such as long processing times and the requirement for sophisticated laboratory instruments. Therefore, there is an urgent need for fast and accurate techniques for virus detection. For this purpose, a variety of biosensor systems are being developed to provide rapid, sensitive, and high-throughput viral diagnostic platforms, enabling quick diagnosis and efficient control of the virus's spread. Optical devices, in particular, are of great interest due to their advantages such as high sensitivity and direct readout. The current review discusses solid-phase optical sensing techniques for virus detection, including fluorescence-based sensors, surface plasmon resonance (SPR), surface-enhanced Raman scattering (SERS), optical resonators, and interferometry-based platforms. Then, we focus on an interferometric biosensor developed by our group, the single-particle interferometric reflectance imaging sensor (SP-IRIS), which has the capability to visualize single nanoparticles, to demonstrate its application for digital virus detection.

Highly-Sensitive, Label-Free Detection of Microorganisms and Viruses via Interferometric Reflectance Imaging Sensor.

Pathogenic microorganisms and viruses can easily transfer from one host to another and cause disease in humans. The determination of these pathogens in a time- and cost-effective way is an extreme challenge for researchers. Rapid and label-free detection of pathogenic microorganisms and viruses is critical in ensuring rapid and appropriate treatment. Sensor technologies have shown considerable advancements in viral diagnostics, demonstrating their great potential for being fast and sensitive detection platforms. In this review, we present a summary of the use of an interferometric reflectance imaging sensor (IRIS) for the detection of microorganisms. We highlight low magnification modality of IRIS as an ensemble biomolecular mass measurement technique and high magnification modality for the digital detection of individual nanoparticles and viruses. We discuss the two different modalities of IRIS and their applications in the sensitive detection of microorganisms and viruses.