Biomolecule conjugated inorganic nanoparticles for biomedical applications: A review

Engineering colloidal systems for cell manipulation, delivery, and tracking

Men-made colloidal systems are widely presented across various aspects of biomedical science. There is a strong demand for engineering colloids to tailor their functions and properties to meet the requirements of biological and medical tasks. These requirements are not only related to size, shape, capacity to carry bioactive compounds as drug delivery systems, and the ability to navigate via chemical and physical targeting. Today, the more challenging aspects of colloid design are how the colloidal particles interact with biological cells, undergo internalization by cells, how they reside in the cell interior, and whether we can explore cells with colloids, intervene with biochemical processes, and alter cell functionality. Cell tracking, exploitation of cells as natural transporters of internalized colloidal carriers loaded with drugs, and exploring physical methods as external triggers of cell functions are ongoing topics in the research agenda. In this review, we summarize recent advances in these areas, focusing on how colloidal particles interact and are taken up by mesenchymal stem cells, dendritic cells, neurons, macrophages, neutrophils and lymphocytes, red blood cells, and platelets. The engineering of colloidal vesicles with cell membrane fragments and exosomes facilitates their application. The perspectives of different approaches in colloid design, their limitations, and obstacles on the biological side are discussed.

Antibody-Nanoparticle Conjugates in Therapy: Combining the Best of Two Worlds

Monoclonal antibodies (mAbs) and antibody fragments have revolutionized medicine as highly specific binding agents and inhibitors. At the same time, several types of nanomaterials, including liposomes, lipid nanoparticles (NPs), polymersomes, metal and metal oxide NPs, and protein nanostructures, are increasingly utilized and explored for therapeutic potential due to their versatility, chemical and physical properties, and tunability. However, nanomaterials alone often lack specificity, leading to relatively low efficacy and/or high toxicity. To address this problem, a rapidly emerging area is antibody-nanomaterial conjugates (ANCs), which combine the precise targeting specificity of antibodies with the effector functionality of the nanomaterial. In this review, we give a brief introduction to mAbs and major conjugation techniques, describe major classes of nanomaterials being studied for therapeutic potential, and review the literature on ANCs of each class. Special focus is given to emerging applications including ANCs addressing the blood-brain barrier, ANCs delivering nucleic acids, and light-activated ANCs. While many disease targets are related to cancer, ANCs are also under development to address autoimmune, neurological, and infectious diseases. While important challenges remain, ANCs are poised to become a next-generation therapeutic technology.

Optimized synthesis of silver nanoparticles using the marine fungus Aspergillus terreus and its application against resistant nosocomial pathogens

The prevalence of bacterial infections in hospitals is rising, endangering currently accessible, efficient medical treatments and increasing demand for novel medications. Metal nanoparticles (NPs) are showing promise as materials for the development of treatments and preventative measures. This study investigated the potential of the fungus Aspergillus terreus to produce silver nanoparticles (AgNPs) as a means of creating green technology to synthesize NPs. The synthesis parameters were optimized using the central composite design (CCD). The formation of AgNPs by fungal biomass was confirmed by absorption spectroscopy, FTIR, powder XRD, scanning electron microscopy, and transmission electron microscopy. The antibacterial properties of the AgNPs were tested against three nosocomial drug-sensitive bacterial strains and their drug-resistant variants, vancomycin-resistant Enterococcus faecalis, and the multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii. The prepared AgNPs demonstrated good efficacies against the pathogens studied, and they merit further investigation to find treatments for infections caused by drug-resistant nosocomial pathogens.

A comprehensive review on the biomedical frontiers of nanowire applications

This comprehensive review examines the immense capacity of nanowires, nanostructures characterized by unbounded dimensions, to profoundly transform the field of biomedicine. Nanowires, which are created by combining several materials using techniques such as electrospinning and vapor deposition, possess distinct mechanical, optical, and electrical properties. As a result, they are well-suited for use in nanoscale electronic devices, drug delivery systems, chemical sensors, and other applications. The utilization of techniques such as the vapor-liquid-solid (VLS) approach and template-assisted approaches enables the achievement of precision in synthesis. This precision allows for the customization of characteristics, which in turn enables the capability of intracellular sensing and accurate drug administration. Nanowires exhibit potential in biomedical imaging, neural interfacing, and tissue engineering, despite obstacles related to biocompatibility and scalable manufacturing. They possess multifunctional capabilities that have the potential to greatly influence the intersection of nanotechnology and healthcare. Surmounting present obstacles has the potential to unleash the complete capabilities of nanowires, leading to significant improvements in diagnostics, biosensing, regenerative medicine, and next-generation point-of-care medicines.

Evaluation of Advanced Nanomaterials for Cancer Diagnosis and Treatment

Cancer is a persistent global disease and a threat to the human species, with numerous cases reported every year. Over recent decades, a steady but slowly increasing mortality rate has been observed. While many attempts have been made using conventional methods alone as a theragnostic strategy, they have yielded very little success. Most of the shortcomings of such conventional methods can be attributed to the high demands of industrial growth and ever-increasing environmental pollution. This requires some high-tech biomedical interventions and other solutions. Thus, researchers have been compelled to explore alternative methods. This has brought much attention to nanotechnology applications, specifically magnetic nanomaterials, as the sole or conjugated theragnostic methods. The exponential growth of nanomaterials with overlapping applications in various fields is due to their potential properties, which depend on the type of synthesis route used. Either top-down or bottom-up strategies synthesize various types of NPs. The top-down only branches out to one method, i.e., physical, and the bottom-up has two methods, chemical and biological syntheses. This review highlights some synthesis techniques, the types of nanoparticle properties each technique produces, and their potential use in the biomedical field, more specifically for cancer. Despite the evident drawbacks, the success achieved in furthering nanoparticle applications to more complex cancer stages and locations is unmatched.

Toehold-Mediated Shape Transition of Nucleic Acid Nanoparticles

We introduce a toehold-mediated strand displacement strategy for regulated shape-switching of nucleic acid nanoparticles (NANPs) enabling their sequential transformation from triangular to hexagonal architectures at isothermal conditions. The successful shape transitions were confirmed by electrophoretic mobility shift assays, atomic force microscopy, and dynamic light scattering. Furthermore, implementation of split fluorogenic aptamers allowed for monitoring the individual transitions in real time. Three distinct RNA aptamers─malachite green (MG), broccoli, and mango─were embedded within NANPs as reporter domains to confirm shape transitions. While MG "lights up" within the square, pentagonal, and hexagonal constructs, the broccoli is activated only upon formation of pentagon and hexagon NANPs, and mango reports only the presence of hexagons. Moreover, the designed RNA fluorogenic platform can be employed to construct a logic gate that performs an AND operation with three single-stranded RNA inputs by implementing a non-sequential polygon transformation approach. Importantly, the polygonal scaffolds displayed promising potential as drug delivery agents and biosensors. All polygons exhibited effective cellular internalization followed by specific gene silencing when decorated with fluorophores and RNAi inducers. This work offers a new perspective for the design of toehold-mediated shape-switching nanodevices to activate different light-up aptamers for the development of biosensors, logic gates, and therapeutic devices in the nucleic acid nanotechnology.