Empirical and theoretical insights into the structural effects of selenite doping in hydroxyapatite and the ensuing inhibition of osteoclasts

Micronesian maritime piloting charts as bioimaging proxies for the rescue of cells on the apoptotic trajectory

This interdisciplinary study falls within the realm of ethnoscience thanks to its resorting to the scientific methods behind the Micronesian canoe voyaging in search of bioimaging tools for the early prediction of cell fate in response to a therapy. Two distinct indigenous methods for navigation across the ocean were assessed as bridges for correlating (i) the interaction of oceanic swells near atolls with the way microcurrents in the cell culture dish may shape the morphology of cells, and (ii) the spatial arrangement of cultured cells with the canoe voyaging from one island to the next. Both methods effectively predicted the cell fate at early time points in the treatment with superparamagnetic nanoparticles, when the adverse effects were still reversible and not apparent yet at the levels of cell morphology, proliferation rate or confluence. The mattang chart, the most fundamental and theoretical of navigational devices used in the Marshallese seafaring tradition, was used to measure subtle morphological changes occurring in cells due to the treatment. The cells subjected to the treatment were consistently withdrawing their bodies from the areas of intense swell interaction activity on the superimposed mattangs. Given that the cytoskeletal microfilaments defining the features of control cells were largely filling up these areas, this metric proved useful for deducing the course of the treatment at its early stages. The same deduction was proven feasible with the use of a Carolinian navigational technique based on the concept of the etak, in which case the distances traversable between cells in a population subjected to the treatment were divisible to a significantly higher number of etaks than the same distances in the population of control cells. Therefore, treating cells and their nuclei as analogous to Pacific atolls navigable to and fro with the use of imaginary microscopic canoes and the navigational principles native to the Marshall and the Caroline Islands proves as a clever, but also very effective cell fate prediction approach, which various branches of biomedical science could take advantage of. These practical benefits notwithstanding, this conceptual study was performed primarily with a goal to spark the interest in studying these and other ancient ethnoscientific inventions as potential addenda to the broad repertoire of techniques used in biomedical and other sciences to combat some of their greatest challenges.

Polymeric Nanotechnologies for the Treatment of Periodontitis: A Chronological Review

Periodontitis is a chronic infectious and inflammatory disease of periodontal tissues estimated to affect 70 - 80 % of all adults. At the same time, periodontium, the site of periodontal pathologies, is an extraordinarily complex plexus of soft and hard tissues, the regeneration of which using even the most advanced forms of tissue engineering continues to be a challenge. Nanotechnologies, meanwhile, have provided exquisite tools for producing biomaterials and pharmaceutical formulations capable of elevating the efficacies of standard pharmacotherapies and surgical approaches to whole new levels. A bibliographic analysis provided here demonstrates a continuously increasing research output of studies on the use of nanotechnologies in the management of periodontal disease, even when they are normalized to the total output of studies on periodontitis. The great majority of biomaterials used to tackle periodontitis, including those that pioneered this interesting field, have been polymeric. In this article, a chronological review of polymeric nanotechnologies for the treatment of periodontitis is provided, focusing on the major conceptual innovations since the late 1990s, when the first nanostructures for the treatment of periodontal diseases were fabricated. In the opening sections, the etiology and pathogenesis of periodontitis and the anatomical and histological characteristics of the periodontium are being described, along with the general clinical manifestations of the disease and the standard means of its therapy. The most prospective chemistries in the design of polymers for these applications are also elaborated. It is concluded that the amount of innovation in this field is on the rise, despite the fact that most studies are focused on the refinement of already established paradigms in tissue engineering rather than on the development of revolutionary new concepts.

Structure, Photoluminescence Emissions, and Photocatalytic Activity of Ag2SeO3: A Joint Experimental and Theoretical Investigation

In this paper, we report the synthesis of silver selenite (Ag₂SeO₃) by different methods [sonochemistry, ultrasonic probe, coprecipitation, and microwave-assisted hydrothermal methods]. These microcrystals presented a structural long-range order as confirmed by X-ray diffraction (XRD) and Rietveld refinements and a structural short-range order as confirmed by Fourier transform infrared (FTIR) and Raman spectroscopies. X-ray photoelectron spectroscopy (XPS) provided information about the surface of the samples indicating that they were pure. The microcrystals presented different morphologies and sizes due to the synthesis method as observed by field emission scanning electron microscopy (FE-SEM). The optical properties of these microcrystals were evaluated by ultraviolet-visible (UV-vis) spectroscopy and photoluminescence (PL) measurements. Thermal analysis confirmed the temperature stability of the as-synthetized samples. Further trapping experiments prove that the holes and hydroxyl radicals, to a minor extent, are responsible for the photocatalytic reactions. The experimental results are sustained by first-principles calculations, at the density functional theory (DFT) level, to decipher the structural parameters, electronic properties of the bulk, and surfaces of Ag₂SeO₃. By matching the experimental FE-SEM images and theoretical morphologies, we are capable of finding a correlation between the morphology and photocatalytic activity, along with photodegradation of the Rhodamine B dye under UV light, based on the different numbers of unsaturated superficial Ag and Se cations (local coordination, i.e., clusters) of each surface.

The degradation of methylene blue dye using copper-doped hydroxyapatite encapsulated into polycaprolactone nanofibrous membranes

Methylene blue is degraded under visible light irradiation in the presence of the nanofibrous membranes of PCL containing modified HAP with different contents of Cu ions.