Assessment of in vitro kinetics and biological impact of nebulized trehalose on human bronchial epithelium

Effect of milling and defatting treatment on texture and digestion properties of oat rice

Oat rice with great sensory acceptance was developed based on the combination method of milling and defatting (petroleum ether) treatment. In this study, the effect of milling and defatting treatment on the texture and digestion properties of oat rice was investigated. Results showed that milling and defatting treatment enhanced stickiness, enthalpy, and starch digestibility. The pasting temperature and hardness of oat rice were reduced. The lipid content of oat rice was significantly reduced by milling and defatting treatment, leading to a decrease in the formation of starch-lipid complex. Fourier transform infrared spectroscopy and X-ray diffraction analyses revealed that the application of milling and defatting treatments led to a reduction in the content of starch-lipid complexes in oats during the cooking process. Milling and defatting significantly enhanced both the rapid and slow digestion rates of oat rice. Specifically, the rapid digestion rate was found to be 2.5 times higher than the slow digestion rate. The nutritive components of oat rice were properly preserved, and the viscosity and elasticity of oat rice reached the maximum when milling for 40 s and defatting. This study provides a theoretical basis for oat products.

Inhaled dry powder liposomal azithromycin for treatment of chronic lower respiratory tract infection

A dry powder inhaled liposomal azithromycin formulation was developed for the treatment of chronic respiratory diseases such as cystic fibrosis and bronchiectasis. Key properties including liposome size, charge and encapsulation efficiency powder size, shape, glass transition temperature (Tg), water content and in vitro respiratory deposition were determined. Antimicrobial activity against cystic fibrosis (CF) respiratory pathogens was determined by MIC, MBC and biofilm assays. Cytotoxicity and cellular uptake studies were performed using A549 cells. The average liposome size was 105 nm, charge was 55 mV and encapsulation efficiency was 75 %. The mean powder particle size d[v,50] of 4.54 µm and Mass Median Aerodynamic Diameter (MMAD) was 5.23 µm with a mean Tg of 76˚C and water content of 2.1 %. These excellent physicochemical characteristics were maintained over one year. Liposomal loaded azithromycin demonstrated enhanced activity against P. aeruginosa clinical isolates grown in biofilm. The formulation was rapidly delivered into bacterial cells with > 75 % uptake in 1 h. Rapid uptake into A549 cells via a cholesterol-dependent endocytosis pathway with no cytotoxic effects apparent. These data demonstrate that this formulation could offer benefits over current treatment regimens for people with chronic respiratory infection.

Effects of milling on texture and in vitro starch digestibility of oat rice

Compared with other oat products, consumers in China prefer oat rice and porridge made from naked oat. However, this oat product usually has poor sensory acceptance, which is directly related to the texture properties. This study aimed to use the milling method to improve the oat rice texture. The nutrient component, microstructure, pasting, and thermal properties of oat treated with different degrees of milling (0 s, 20 s, 40 s, 60 s, and 80 s) were researched. The results showed that milling would damage the bran layer of oat rice, increasing starch, β-glucan, total leached solids content, and the gelatinization enthalpy (ΔH). Meanwhile, oil, protein content, the pasting viscosity, and the pasting temperature were decreased. Milling made oat rice sticky and soft, and the bound water and non-flowing water migrated like flowing water. The cross-section of oat rice showed that milling damaged the surface of oat rice, which was beneficial to water entry and starch dissolution, and increased the viscosity of oat rice. When the milling time was 40 s and 60 s, the appearance, aroma, taste, texture, and overall acceptability of oat porridge were better. Moreover, rapid digestion fraction (k1) and slow digestion fraction (k2) are the lowest and have the effect of low blood glucose rise rate.

Nanoparticulate impurities in the pharmaceutical excipient trehalose induce an early immune response

BACKGROUND

Pharmaceutical excipients are an important part of biological products. However, few attempts have been made to distinguish between the risk of inflammation associated with the biological products themselves and that associated with excipients. The analysis of early immune response risk associated with excipients added to biological products is an important step in exploring the complex mechanism of side effects in susceptible patients.

METHODS AND RESULTS

In this study, nanoparticle impurities (NPIs) were extracted from trehalose and characterized. A mouse popliteal lymph node cell (PLNA) model, a mouse spleen lymphocyte model, a human peripheral blood mononuclear cell cytokine release model, and a macrophage complement activation model were established to comprehensively evaluate the early immune risk related to impurities in the trehalose excipient. Although popliteal lymph node cell counts in mice did not show significant differences, all other models indicated possible immune risk. In the PLNA model, NPIs caused significant toe thickening in mice, whereby the content of IgE and MCP-1 increased significantly. NPIs significantly increased the proliferation and differentiation of spleen lymphocytes according to the CCK-8 assay and flow cytometry. After treatment with NPIs, the release of IgE and a variety of cytokines (MIP-1α, IFN-γ, IL-2, IL-8, TNF-α, IL-6, IL-1α) in human peripheral blood cells was significantly increased according to ELISA, while a concomitant increase of C3a/C5a as well as C4a/Bb proved that NPIs activated the complement system.

CONCLUSION

NPIs from trehalose elicited an immune response in vitro, and the immune response to trehalose may be related to NPIs and not the excipient itself. Different batches of trehalose showed different immune response effects. The currents research suggests that when trehalose is applied in high-risk administration routes, NPIs should be assessed and reasonably controlled.

Synthesis and Application of Trehalose Materials

Trehalose is a naturally occurring, nonreducing disaccharide that is widely used in the biopharmaceutical, food, and cosmetic industries due to its stabilizing and cryoprotective properties. Over the years, scientists have developed methodologies to synthesize linear polymers with trehalose units either in the polymer backbone or as pendant groups. These macromolecules provide unique properties and characteristics, which often outperform trehalose itself. Additionally, numerous reports have focused on the synthesis and formulation of materials based on trehalose, such as nanoparticles, hydrogels, and thermoset networks. Among many applications, these polymers and materials have been used as protein stabilizers, as gene delivery systems, and to prevent amyloid aggregate formation. In this Perspective, recent developments in the synthesis and application of trehalose-based linear polymers, hydrogels, and nanomaterials are discussed, with a focus on utilization in the biomedical field.