Freeze-drying-induced mutarotation of lactose detected by Raman spectroscopy.

Freeze-drying enables delicate, heat-sensitive biomaterials to be stored in a dry form even at room temperature. However, exposure to physicochemical stress induced by freeze-drying presents challenges for maintaining material characteristics and functionality upon reconstitution, for which reason excipients are required. Although wide variety of different excipients are available for pharmaceutical applications, their protective role in the freeze-drying is not yet fully understood.

Inline Raman Spectroscopy Provides Versatile Molecular Monitoring for Platelet Extracellular Vesicle Purification with Anion-Exchange Chromatography.

Extracellular vesicles (EVs) are relatively recently discovered biological nanoparticles that mediate intercellular communication. The development of new methods for the isolation and characterization of EVs is crucial to support further studies on these small and structurally heterogenous vesicles. New scalable production methods are also needed to meet the needs of future therapeutic applications.

Intracellular Dynamics of Extracellular Vesicles by Segmented Trajectory Analysis.

The analysis of nanoparticle (NP) dynamics in live cell studies by video tracking provides detailed information on their interactions and trafficking in the cells. Although the video analysis is not yet routinely used in NP studies, the equipment suitable for the experiments is already available in most laboratories. Here, we compare trajectory patterns, diffusion coefficients, and particle velocities of NPs in A549 cells with a rather simple experimental setup consisting of a fluorescence microscope and openly available trajectory analysis software.

Correction: Addressing challenges in the removal of unbound dye from passively labelled extracellular vesicles.

[This corrects the article DOI: 10.1039/D1NA00755F.].

Addressing challenges in the removal of unbound dye from passively labelled extracellular vesicles.

Studies of extracellular vesicles (EVs), their trafficking and characterization often employ fluorescent labelling. Unfortunately, little attention has been paid thus far to a thorough evaluation of the purification of EVs after labelling, although the presence of an unbound dye may severely compromise the results or even lead to wrong conclusions on EV functionality. Here, we systematically studied five dyes for passive EV labelling and meticulously compared five typical purification methods: ultracentrifugation (UC), ultracentrifugation with discontinuous density gradient (UCG), ultrafiltration (UF), size exclusion chromatography (SEC), and anion exchange chromatography (AEC).

Infrared and Raman spectroscopy for purity assessment of extracellular vesicles.

Extracellular vesicles (EVs) are a complex and heterogeneous population of nanoparticles involved in cell-to-cell communication. Recently, numerous studies have indicated the potential of EVs as therapeutic agents, drug carriers and diagnostic tools. However, the results of these studies are often difficult to evaluate, since different characterization methods are used to assess the purity, physical and biochemical characteristics of the EV samples.

Molecular Insights on Successful Reconstitution of Freeze-Dried Nanofibrillated Cellulose Hydrogel.

The diversity and safety of nanofibrillated cellulose (NFC) hydrogels have gained a vast amount of interest at the pharmaceutical site in recent years. Moreover, this biomaterial has a high potential to be utilized as a protective matrix during the freeze-drying of heat-sensitive pharmaceuticals and biologics to increase their properties for long-term storing at room temperature and transportation. Since freeze-drying and subsequent reconstitution have not been optimized for this biomaterial, we must find a wider understanding of the process itself as well as the molecular level interactions between the NFC hydrogel and the most suitable lyoprotectants.

Preservation of biomaterials and cells by freeze-drying: Change of paradigm.

Freeze-drying is the most widespread method to preserve protein drugs and vaccines in a dry form facilitating their storage and transportation without the laborious and expensive cold chain. Extending this method for the preservation of natural biomaterials and cells in a dry form would provide similar benefits, but most results in the domain are still below expectations. In this review, rather than consider freeze-drying as a traditional black box we "break it" through a detailed process thinking approach.

Drug diffusivities in nanofibrillar cellulose hydrogel by combined time-resolved Raman and fluorescence spectroscopy.

Hydrogels, natural and synthetic origin, are actively studied for their use for implants and payload carriers. These biomaterials for delivery systems have enormous potential in basic biomedical research, drug development, and long-term delivery of biologics. Nanofibrillated cellulose (NFC) hydrogels, both natural and anionic (ANFC) ones, allow drug loading for immediate and controlled release via the slow drug dissolution of solid drug crystals into hydrogel and its subsequent release.