The use of materials to restore or replace the functions of damaged body parts has been proven historically. Any material can be considered as a biomaterial as long as it performs its biological function and does not cause adverse effects to the host. With the increasing demands for biofunctionality, biomaterials nowadays may not only encompass inertness but also specialized utility towards the target biological application. A hydrogel is a biomaterial with a 3D network made of hydrophilic polymers. It is regarded as one of the earliest biomaterials developed for human use. The preparation of hydrogel is often attributed to the polymerization of monomers or crosslinking of hydrophilic polymers to achieve the desired ability to hold large amounts of aqueous solvents and biological fluids. The generation of hydrogels, however, is shifting towards developing hydrogels through the aid of enabling technologies. This review provides the evolution of hydrogels and the different approaches considered for hydrogel preparation. Further, this review presents the plasma process as an enabling technology for tailoring hydrogel properties. The mechanism of plasma-assisted treatment during hydrogel synthesis and the current use of the plasma-treated hydrogels are also discussed.
Chromatin compaction and regulation are essential processes for the normal function of all organisms, yet knowledge on how archaeal chromosomes are packed into higher-order structures inside the cell remains elusive. In this study, we investigated the role of archaeal architectural proteins Alba and Cren7 in chromatin folding and dynamics. Atomic force microscopy revealed that Sulfolobus solfataricus chromatin is composed of 28 nm fibers and 60 nm globular structures. In vitro reconstitution showed that Alba can mediate the formation of folded DNA structures in a concentration-dependent manner. Notably, it was demonstrated that Alba on its own can form higher-order structures with DNA. Meanwhile, Cren7 was observed to affect the formation of Alba-mediated higher-order chromatin structures. Overall, the results suggest an interplay between Alba and Cren7 in regulating chromatin compaction in archaea.
10 April 2023 in Journal of Vacuum Science & Technology B
This study explores the effect of atmospheric pressure plasma (APP) treatment on chitosan-acrylic acid (Cs-AA) blends. The experiment involves a custom-built APP setup used to modify a polymeric blend composed of natural (Cs) and synthetic (AA) polymers. Even with a low process temperature (<40 °C), reactive oxygen and nitrogen species (RONS) were observed in an air plasma plume. The interaction of plasma with the liquid surface was also observed. With de-ionized water as the test liquid, the operating parameters such as the treatment time and flow rate were shown to influence the pH and absorption spectrum of the liquid. The presence of RONS was investigated using optical emission spectroscopy coupled with principal component analysis. The analysis revealed that the air plasma contains the different N systems, NO, OH, H α, monatomic N, and monatomic O species. Varying the gas flow rate influences the production of NO and OH radicals while measuring plasma discharge in different conditions (ambient air, DI H 2O, Cs, and Cs-AA blend) affects the concentration of the N positive and negative systems. The effect of these RONS on the Cs-AA blends was also investigated by assessing the chemical structure, pH, and viscosity of the solution. In correlation with all of the findings, it was observed that plasma treatment could degrade pure Cs solution by dehydrogenation and glycosidic bond cleaving. However, the addition of AA reduces the degradation so that the AA radicals created by plasma form a complex with the Cs that reduces Cs fragmentation and chain entanglement, as observed in the reduction of viscosity. In summary, the rich reactive species created by plasma in the Cs-AA solution not only provided stable species but also introduced more Cs-AA complexes.
Archaeal species encode a diversity of chromatin proteins that play distinct roles in genome compaction. Although our understanding of the individual proteins has been growing, their contributions to higher‐order folding in the archaeal chromosome remain to be explored. In this study, we investigated the chromatin structure of Thermoplasma volcanium, a euryarchaeon that encodes a heat‐unstable (HU) family protein (HUTvo) instead of histones. Atomic force microscopy revealed that the T. volcanium chromatin contains nucleoprotein structures of progressively increasing sizes, from 20 nm filaments to ~50 nm globules, indicative of higher‐order DNA folding. In vitro reconstitution showed that HUTvo wraps DNA similar to histones and forms highly compact yet disorganized nucleoprotein clusters on its own. Remarkably, HUTvo only dampens the formation of higher‐order structures by Alba. Our results provide an insight into how the interplay of chromatin proteins regulates genome compaction in histone‐free archaea.