3D-engineered nano-architectures with various functionalities are still difficult to obtain and translate for real-world applications. However, such nanomaterials are naturally abundant and yet wasted, but could trigger huge interest for blue bioeconomy, provided that our understanding of their ultrastructure-function is achieved. To date, the Bouligand pattern in crustaceans shell structure is believed to be unique. Here we demonstrated that in blue crab Callinectes sapidus, the 3D-nanoarchitecture is color-specific, while the blue and red-orange pigments interplay in different nano-sized channels and pores. Thinnest pores of about 20 nm are found in blue shell. Additionally, the blue pigment co-existence in specific Bouligand structure is proved for the green crab Carcinus aestuarii, although the crab does not appear blue. The pigments interplay, simultaneously detected by Raman spectroscopy in color-specific native cuticles, overturns our understanding in crustaceans coloration and may trigger the selective use of particular colored natural nanoarchitectures for broaden area of applications.

In the last few years elemental imaging by laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) has advanced rapidly, both due to hardware development associated with fast aerosol transport technologies and a deeper understanding of the influence of operational parameters on the image quality. Herein we describe the effect of dosage, i.e., the number of laser pulses per pixel, on the image quality attainable by LA-ICP-QMS as illustrated by mapping of a biological (murine brain tissue) and a mineralogical (asbestos fibers) sample. The usage of higher dosages results in better S/N ratios and is crucial when elements are present at lower concentration levels, or if mapping of more than one element is required. While this potentially increases the mapping time, elemental images with higher dosages will generally be of better quality.

Mineralogical studies performed on crusts, nodules and earthy masses from the Romanian caves Gaura cu Muscă, Gaura Haiducească and Peștera Zidită have revealed the presence of three different phosphate associations. The minerals have been identified by means of X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Five phosphates have been identified in the samples, with hydroxylapatite the only common mineral in all the three caves. Brushite, taranakite, leucophosphite and variscite are the other phosphates identified. Associated minerals include gypsum, calcite, quartz and illite-group minerals. Aside from differences in the lithology, the occurrences of the different phosphate minerals indicate variable pH and humidity conditions near or within the guano accumulations.

A biogenic carrier for 5-fluorouracil (5-FU) loading and subsequent tableting as a new drug formulation for slow release has been proposed using the biomineral from blue crab carapace. Due to its highly ordered 3D porous nanoarchitecture, the biogenic carbonate carrier could achieve increased effectiveness in colorectal cancer cure provided that the formulation would successfully pass through the gastric acid conditions. Following the recently proven viability of the concept by demonstrating the slow release of the drug from the carrier using the highly sensitive SERS technique, here we investigated the 5-FU release from the composite tablet drug in pH conditions replicating the gastric environment. The released drug from the tablet was studied in solutions with three relevant pH values, pH 2, pH 3, and pH 4. The 5-FU SERS spectral signature for each pH value was used to build calibration curves for quantitative SERS analysis. The results suggested a similarly slow-releasing pattern in acid pH environments to that in neutral conditions. Although biogenic calcite dissolution was expected in acid conditions, the X-ray diffraction and Raman spectroscopy showed preservation of calcite mineral along with the monohydrocalcite during acid solution exposure for two hours. The total released amount in a time course of seven hours, however, was lower in acidic pH solutions, with a maximum fraction of ~40% of the total amount of loaded drug, for pH 2, as opposed to ~80% for neutral values. Nonetheless, these results clearly prove that the novel composite drug retains its slow-releasing character in environmental conditions compatible with the gastrointestinal pH and that it is a viable and biocompatible alternative for oral delivery of anticancer drug to reach the lower gastro-intestinal tract.

The multi-component solid form of febuxostat (FEB) with p-toluenesulfonic acid was synthesized by solvent-drop grinding and cooling-evaporative crystallization and characterized by powder X-ray diffraction (XRPD), thermogravimetry (TGA), differential scanning calorimetry (DSC), and infrared spectroscopy (FT-IR). The multi-component form was stable after exposure at elevated temperature and relative humidity and powder dissolution measurements revealed five-fold aqueous solubility improvement relative to FEB. Additionally, the decrease in pH after dissolution suggests a potential for enhancing the drug absorption in the lower stomach. In the context of the regulatory requirements, the salt/co-crystal nature of the form was elucidated by a combination of crystallization process development and crystal growth, followed by SC-XRD and FT-IR. Despite the very weak basicity of the drug, crystal structure determination combined with spectroscopy analysis revealed salt formation by the transfer of the acidic proton from p-toluenesulfonic acid to FEB. Our study emphasizes the importance of the crystal structure knowledge in understanding the type of interactions present in multi-component crystals as well as complying with the specific regulatory requirements.