Natural biopolymers in the fabrication and coating of ureteral stent: An overview.

Ureteral stents are indwelling medical devices that are most commonly used in treating different urinary tract complications like ureteral obstruction, kidney stones, and strictures, and allow normal urine flow from the kidney to the bladder. Tremendous work has been done in ureteral stent technology to meet the clinical demands, however, till-date a gold standard material for ureteral stents has not yet been developed. Many materials such as metal, and synthetic polymers have been published, however, the role of natural biopolymers has not yet been summarized and discussed. There is no detailed review published to explain the role of natural biopolymers in ureteral stent technology. This is the first review that explains and summarizes the role of natural polymer in ureter stent technology. In this review alginate and chitosan polymers are discussed in detail in the fabrications and coating of ureteral stents. It was summarized that alginate polymer alone or in combination with other polymers have been successfully used by many researchers for the manufacturing of ureteral stents with satisfactory results in vitro, in vivo, and clinical trials. However, alginate is rarely used to coat the surface of ureteral stent. On the other hand, only two reports are available on chitosan polymers for the manufacturing of ureteral stents, however, chitosan is largely used to coat the existing ureteral stents owing to their good antibacterial characteristics. Coating procedures can inhibit encrustation and biofilm formation. Nevertheless, the lack of antibacterial efficiency and inadequate coating limit their applications, however, natural biopolymers like chitosan showed significant promises in coating. Overall, the renewable nature, abundant, biocompatible, and biodegradable potential of natural polymer can be established with significant aspects as the ideal ureteral stent. To fully utilize the potential of the natural biopolymers in the ureteral stent design or coatings, an in-depth study is required to understand and identify their performance both in vitro and in vivo in the urinary tract.

Emerging vaccine nanotechnology: From defense against infection to sniping cancer

Looking retrospectively at the development of humanity, vaccination is an unprecedented medical landmark that saves lives by harnessing the human immune system. During the ongoing coronavirus disease 2019 (COVID-19) pandemic, vaccination is still the most effective defense modality. The successful clinical application of the lipid nanoparticle-based Pfizer/BioNTech and Moderna mRNA COVID-19 vaccines highlights promising future of nanotechnology in vaccine development. Compared with conventional vaccines, nanovaccines are supposed to have advantages in lymph node accumulation, antigen assembly, and antigen presentation; they also have, unique pathogen biomimicry properties because of well-organized combination of multiple immune factors. Beyond infectious diseases, vaccine nanotechnology also exhibits considerable potential for cancer treatment. The ultimate goal of cancer vaccines is to fully mobilize the potency of the immune system as a living therapeutic to recognize tumor antigens and eliminate tumor cells, and nanotechnologies have the requisite properties to realize this goal. In this review, we summarize the recent advances in vaccine nanotechnology from infectious disease prevention to cancer immunotherapy and highlight the different types of materials, mechanisms, administration methods, as well as future perspectives.

Nano-bio interfaces effect of two-dimensional nanomaterials and their applications in cancer immunotherapy

The field of two-dimensional (2D) nanomaterial-based cancer immunotherapy combines research from multiple subdisciplines of material science, nano-chemistry, in particular nano-biological interactions, immunology, and medicinal chemistry. Most importantly, the "biological identity" of nanomaterials governed by bio-molecular corona in terms of bimolecular types, relative abundance, and conformation at the nanomaterial surface is now believed to influence blood circulation time, bio-distribution, immune response, cellular uptake, and intracellular trafficking. A better understanding of nano-bio interactions can improve utilization of 2D nano-architectures for cancer immunotherapy and immunotheranostics, allowing them to be adapted or modified to treat other immune dysregulation syndromes including autoimmune diseases or inflammation, infection, tissue regeneration, and transplantation. The manuscript reviews the biological interactions and immunotherapeutic applications of 2D nanomaterials, including understanding their interactions with biological molecules of the immune system, summarizes and prospects the applications of 2D nanomaterials in cancer immunotherapy.