Protein reservoirs of seeds are amyloid composites employed differentially for germination and seedling emergence.

Seed protein localization in seed storage protein bodies (SSPB) and their significance in germination are well recognized. SSPB are spherical and contain an assembly of water-soluble and salt-soluble proteins. Although the native structures of some SSPB proteins are explored, their structural arrangement to the functional correlation in SSPB remains unknown. SSPB are morphologically analogous to electron-dense amyloid-containing structures reported in other organisms. Here, we show that wheat, mungbean, barley, and chickpea SSPB exhibit a speckled pattern of amyloids interspersed in an amyloid-like matrix along with native structures, suggesting the composite nature of SSPB. This is confirmed by multispectral imaging methods, electron microscopy, infrared, and X-ray diffraction analysis, using in situ tissue sections, ex vivo protoplasts, and in vitro SSPB. Laser capture microdissection coupled with peptide fingerprinting has shown that globulin 1 and 3 in wheat, and 8S globulin and conglycinin in mungbean are the major amyloidogenic proteins. The amyloid composites undergo a sustained degradation during germination and seedling growth, facilitated by an intricate interplay of plant hormones and proteases. These results would lay down the foundation for understanding the amyloid composite structure during SSPB biogenesis and its evolution across the plant kingdom and have implications in both basic and applied plant biology.

Necessity of regulatory guidelines for the development of amyloid based biomaterials.

Amyloid diseases are caused due to protein homeostasis failure where incorrectly folded proteins/peptides form cross-ß-sheet rich amyloid fibrillar structures. Besides proteins/peptides, small metabolite assemblies also exhibit amyloid-like features. These structures are linked to several human and animal diseases. In addition, non-toxic amyloids with diverse physiological roles are characterized as a new functional class. This finding, along with the unique properties of amyloid like stability and mechanical strength, led to a surge in the development of amyloid-based biomaterials. However, the usage of these materials by humans and animals may pose a health risk such as the development of amyloid diseases and toxicity. This is possible because amyloid-based biomaterials and their fragments may assist seeding and cross-seeding mechanisms of amyloid formation in the body. This review summarizes the potential uses of amyloids as biomaterials, the concerns regarding their usage, and a prescribed workflow to initiate a regulatory approach.

Likelihood of amyloid formation in COVID-19-induced ARDS.

Severe coronavirus disease 2019 (COVID-19) infection leads to multifactorial acute respiratory distress syndrome (ARDS), with little therapeutic success. The pathophysiology associated with ARDS or post-ARDS is not yet well understood. We hypothesize that amyloid formation occurring due to protein homeostasis disruption can be one of the complications associated with COVID-19-induced-ARDS.

Analytical validation of an ATR-FTIR based method for quantifying the amount of polysorbate 80 adsorbed on PLGA nanoparticles.

Nanoparticle-based drug delivery systems for crossing the blood-brain barrier employ diverse strategies. Coating of nanoparticles with non-ionic surfactants is often employed for enhancing the delivery process. Polysorbate 80 is one of the non-ionic surfactants used as a coating agent for facilitating receptor-mediated endocytosis into the brain. However, very few studies have been done to quantitate the actual amount of the surfactant adsorbed onto nanoparticles. Earlier we had developed an extraction method of adsorbed polysorbate 80 from PLGA nanoparticles and used an attenuated total reflection Fourier transform infrared (ATR-FTIR) method for polysorbate 80 quantitation. Here we show the analytical validation of this method, for its suitability in various applications as per compliance set by regulatory bodies. The validation of the method was done by considering ICH and FDA guidelines for accuracy, precision, linearity, range, limit of detection, and limit of quantitation parameters. The method successfully complied with all the parameters and is therefore found to be suitable for successful use in industry and academia and by regulatory bodies.