Efficient virus detection utilizing chitin-immobilized nanobodies synthesized in Ustilago maydis.

The COVID-19 pandemic has greatly impacted the global economy and health care systems, illustrating the urgent need for timely and inexpensive responses to pandemic threats in the form of vaccines and antigen tests. Currently, antigen testing is mostly conducted by qualitative flow chromatography or via quantitative ELISA-type assays. The latter mostly utilize materials like protein-adhesive polymers and gold or latex particles. Here we present an alternative ELISA approach using inexpensive, biogenic materials and permitting quick detection based on components produced in the microbial model Ustilago maydis. In this fungus, heterologous proteins like biopharmaceuticals can be exported by fusion to unconventionally secreted chitinase Cts1. As a unique feature, the carrier chitinase binds to chitin allowing its additional use as a purification or immobilization tag. Recent work has demonstrated that nanobodies are suitable target proteins. These proteins represent a very versatile alternative antibody format and can quickly be adapted to detect novel antigens by camelidae immunization or synthetic libraries. In this study, we exemplarily produced different mono- and bivalent SARS-CoV-2 nanobodies directed against the spike protein receptor binding domain (RBD) as Cts1 fusions and screened their antigen binding affinity in vitro and in vivo. Functional nanobody-Cts1 fusions were immobilized on chitin forming an RBD tethering surface. This provides a solid base for future development of inexpensive antigen tests utilizing unconventionally secreted nanobodies as antigen trap and a matching ubiquitous and biogenic surface for immobilization.

Chapter 22 - Antiviral biomolecules from marine inhabitants

In recent years, the healthcare community has faced challenges with viral infections, which they believe pose a significant threat to humanity. Because of the emergence and reemergence of these viral diseases, including the ongoing COVID-19 pandemic, there is an urgent need for novel drug discovery and potential antiviral therapeutics to combat these situations. Scientists are increasing focusing on marine-derived biomaterials, which have been shown to have a variety of effective antiviral activities, although there is some lag. This chapter highlights some of the studies that have been conducted on the antiviral activities of polysaccharides and antimicrobial peptides derived from marine organisms. It will specifically recall the antiviral activities of peptides and sulfated polysaccharides derived from the marine environment, such as tachyplesin, polyphemusin, chitin, chitosan, carrageenans, alginates, and fucans, among others. Furthermore, recent findings on the anti-SARS-CoV-2 action of some marine polysaccharides are also briefly summarized.

Statewide Efficacy Assessment of Insect Growth Regulators Against Aedes albopictus (Diptera: Culicidae) in Sabah, Malaysia: An Alternative Control Strategy?

The efficacy of three groups of insect growth regulators, namely juvenile hormone mimics (methoprene and pyriproxyfen), chitin synthesis inhibitors (diflubenzuron and novaluron), and molting disruptor (cyromazine) was evaluated for the first time, against Aedes albopictus Skuse (Diptera: Culicidae) larvae from 14 districts in Sabah, Malaysia. The results showed that all field populations of Ae. albopictus were susceptible towards methoprene, pyriproxyfen, diflubenzuron, novaluron, and cyromazine, with resistance ratio values ranging from 0.50-0.90, 0.60-1.00, 0.67-1.17, 0.71-1.29, and 0.74-1.07, respectively. Overall, the efficacy assessment of insect growth regulators in this study showed promising outcomes and they could be further explored as an alternative to conventional insecticides.

Polysaccharide Stalks in Didymosphenia geminata Diatom: Real World Applications and Strategies to Combat Its Spread

Didymosphenia geminata is a species of freshwater diatom that is known as invasive and is propagating quickly around the world. While invasive species are generally considered a nuisance, this paper attempts to find useful applications for D. geminata in the biomedical field and wastewater remediation. Here, we highlight the polysaccharide-based stalks of D. geminata that enable versatile potential applications and uses as a biopolymer, in drug delivery and wound healing, and as biocompatible scaffolding in cell adhesion and proliferation. Furthermore, this review focuses on how the polysaccharide nature of stalks and their metal-adsorption capacity allows them to have excellent wastewater remediation potential. This work also aims to assess the economic impact of D. geminata, as an invasive species, on its immediate environment. Potential government measures and legislation are recommended to prevent the spread of D. geminata, emphasizing the importance of education and collaboration between stakeholders.

Demodex folliculorum interaction with SARS-CoV2 from a chitin-lipid perspective

During the outbreak of COVID-19 pandemic, regulatory agencies have attempted to figure out the possible routes of SARS-CoV-2 viral transmission. It is hypothesized that the lipid bilayer surrounding the SARS-CoV-2 improves its ability to remain stable on sebum-rich skin and serves as another possible route of contracting the virus. One possible aspect of these observations that has yet to be explored in detail is what role arthropods that have been associated with human skin infestation, such as Demodecidae or Pyemotidae species, play in viral transmission. It seems likely that arthropod-coronavirus interactions may take place through the molecular attraction forces between the chitin found on the exoskeleton of mites commonly found on human skin and the lipids present on the viral envelope of the SARS-CoV-2. We believe this may mean that arthropods are currently an overlooked cofactor in viral infection which may have some important biomedical implications for both prevention and treatment

Antimicrobial sustainable biopolymers for biomedical plastics applications - an overview

The Covid-19 pandemic has increased the need for personal protective equipment (PPE), especially for medical personnel: face masks, full protective clothing, gloves and goggles. To date, they are usually made of thermoplastic polymers, such as polypropylene (PP). To reduce the risk of secondary infections it is essential to enhance the antimicrobial (especially antibacterial and antiviral) properties of the materials used in PPE. There are some attempts to modify materials by, for example, silver nanoparticles or zinc oxides. The increasing demand for personal protective equipment, mostly masks, leads to an increase of environmental problem of non-biodegradable wastes. Therefore some researches on use of safer for user's health sustainable antimicrobial and biodegradable biopolymer fibers, such as cellulose, starch, chitosan, poly(lactic acid) (PLA) or poly(glycolic acid) (PGA), have been done. These biopolymers and their properties are discussed in this article.

Chitin and chitosan as tools to combat COVID-19: A triple approach.

The progressive and fatal outbreak of the newly emerged coronavirus, SARS-CoV-2, necessitates rigorous collaboration of all health care systems and researchers from all around the world to bring such a devastating pandemic under control. As there is so far no officially approved drug or ideal vaccine for this disease, investigations on this infectious disease are actively pursued. Chitin and chitosan have shown promising results against viral infections. In this review, we first delve into the problematic consequences of viral pandemics followed by an introduction on SARS-CoV-2 taxonomical classification. Then, we elaborate on the immunology of COVID-19. Common antiviral therapies and their related limitations are described and finally, the potential applicability of chitin and chitosan to fight this overwhelming viral pandemic is addressed.

Chitin-lipid interactions and the potential relationship between Demodex and SARS-CoV-2.

Already from the early days of the COVID-19 pandemic, regulatory agencies have attempted to ascertain the possible routes of SARS-CoV-2 viral transmission. It is hypothesized that the lipid bilayer that surrounds the SARS-CoV-2 improves its ability to remain stable on sebum-rich skin and serves as another possible route of contracting the virus. One possible aspect of these observations that has yet to be explored in detail is what role arthropods that have been associated with human skin infestation, such as Demodecidae or Pyemotidae species, play in viral transmission. It seems likely that arthropod-coronavirus interactions may take place through the molecular attraction forces between the chitin found on the exoskeleton of mites commonly found on human skin and the lipids present on the viral envelope of the SARS-CoV-2. We believe this may mean that arthropods are currently an overlooked cofactor in viral infection which may have some important biomedical implications for both prevention and treatment.