Metal selenide nanomaterials for biomedical applications

The remarkable properties of graphene have renewed interest in inorganic, two-dimensional materials with unique electronic and optical attributes. Transition metal dichalcogenides (TMDCs) are layered materials with strong in-plane bonding and weak out-of-plane interactions enabling exfoliation into two-dimensional layers of single unit cell thickness. Although TMDCs have been studied for decades, recent advances in nanoscale materials characterization and device fabrication have opened up new opportunities for two-dimensional layers of thin TMDCs in nanoelectronics and optoelectronics. TMDCs such as MoS(2), MoSe(2), WS(2) and WSe(2) have sizable bandgaps that change from indirect to direct in single layers, allowing applications such as transistors, photodetectors and electroluminescent devices. We review the historical development of TMDCs, methods for preparing atomically thin layers, their electronic and optical properties, and prospects for future advances in electronics and optoelectronics.

Nanoparticle-based therapeutic, prevention, and detection modalities have the potential to greatly impact how diseases are diagnosed and managed in the clinic. With the wide range of different nanomaterials available to nanomedicine researchers, the rational design of nanocarriers on an application-specific basis has become increasingly commonplace. In this review, we provide a comprehensive overview on an emerging platform: cell membrane coating nanotechnology. As one of the most fundamental units in biology, a cell carries out a wide range of functions, including its remarkable ability to interface and interact with its surrounding environment. Instead of attempting to replicate such functions via synthetic techniques, researchers are now directly leveraging naturally derived cell membranes as a means of bestowing nanoparticles with enhanced biointerfacing capabilities. This top-down technique is facile, highly generalizable, and has the potential to greatly augment the potency and safety of existing nanocarriers. Further, the introduction of a natural membrane substrate onto the surface of a nanoparticle has enabled additional applications beyond those already associated with the field of nanomedicine. Despite the relative youth of the cell membrane coating technique, there exists an impressive body of literature on the topic, which will be covered in detail in this review. Overall, there is still significant room for development, as researchers continue to refine existing workflows while finding new and exciting applications that can take advantage of this emerging technology. Cell membrane coating is an emerging nanotechnology. By cloaking nanomaterials in a layer of natural cell membrane, which can be derived from a variety of cell types, it is possible to fabricate nanoplatforms with enhanced surface functionality. This can lead to increased nanoparticle performance in complex biological environments, which can benefit applications like drug delivery, imaging, phototherapies, immunotherapies, and detoxification.

Antibiotic-resistant bacterial infections arising from acquired resistance and/or through biofilm formation necessitate the development of innovative 'outside of the box' therapeutics. Nanomaterial-based therapies are promising tools to combat bacterial infections that are difficult to treat, featuring the capacity to evade existing mechanisms associated with acquired drug resistance. In addition, the unique size and physical properties of nanomaterials give them the capability to target biofilms, overcoming recalcitrant infections. In this Review, we highlight the general mechanisms by which nanomaterials can be used to target bacterial infections associated with acquired antibiotic resistance and biofilms. We emphasize design elements and properties of nanomaterials that can be engineered to enhance potency. Lastly, we present recent progress and remaining challenges for widespread clinical implementation of nanomaterials as antimicrobial therapeutics.