The ever-growing demand for novel, cheaper, and more effective drugs has put nanomedicine and targeted drug delivery to the forefront of scientific innovation. Owing to its porous three-dimensional (3D)-nanostructure and properties, the biogenic calcite from wasted blue crab shells is employed in the present work as a new drug carrier for 5-fluorouracil (5-FU), a drug widely used in cancer therapy. The drug solution has been loaded in the porous nanoarchitecture of the powdered biogenic material and further pelleted in tablets with a 5-FU concentration of 1.748 mg/g. Their structural and morphological properties were characterized using Raman, X-ray diffraction, and scanning electron microscopy. Confocal micro-Raman spectra of tablet surface showed a typical signal of biogenic carbonate with preserved carotenoids and carotenoproteins found in the native waste shell, while the drug Raman signal was absent, indicating its adsorption in the intricate nanoporous biogenic carrier. The slow release of the drug from the newly formulated tablet was investigated by tracking the surface-enhanced Raman scattering (SERS) signal of the tablet solution in a series of time-dependent experiments. The SERS signal quantification is achieved using the well-known SERS spectral fingerprint of 5-fluorouracil aqueous solution adsorbed on Ag nanoparticles. The proof of concept is demonstrated by quantifying the slow release of the drug through the characteristic SERS band intensity of 5-FU in a time course of 26 h. This proof of concept boosted further investigations concerning the released drug identity in simulated solutions that mimic the pH of the upper-and lower gastrointestinal tract, as well as the multiple possibilities to control porosity and composition during powdering and treatment of biogenic material, to achieve the most convenient formulation for relevant biomedical drug delivery. Nonetheless, the present results showed great promise for innovative reusing waste biogenic 3D-nanomaterials of aquatic origin as advantageous drug carriers for slow release purposes, in line with the concept of blue bioeconomy.

No abstract

The recovery and recycling of wasted resources are at the forefront of contemporary global issues. Methods of addressing several different issues may go hand-in-hand with each other, such as linking food waste recycling into bio-based adsorbent materials and wastewater treatment. Crustacean exoskeletons are promising candidates for bio-friendly adsorbents; however, maximizing their efficiency requires the optimization of processing technology. Crustacean meat offers an (often luxury) culinary delicacy, while their waste exoskeletons offer opportunities for smart recycling of the magnesian calcite nanoporous biocomposite. Here, we conduct a structural characterization of the exoskeletons of three crustacean species to assess how the extraction of valuable carotenoids affects prospects for the further valorization of their porous powder. The exoskeleton powder’s composition and morphology were investigated by SEM, Raman spectroscopy, FTIR and XRD. The biomineral component magnesian calcite was recorded both in native and in post-extraction exoskeleton powder. Acetone extraction, however, partially removed organic matter from the exoskeletons, resulting in the porosity of the respective powder increasing significantly from below 10 m2 g−1 in the native powder to over 32 m2 g−1 in post-extraction samples of blue crab and spider crab exoskeletons—while the spiny lobster exoskeleton exhibited low porosity, as measured by the BET method. This new insight could improve exoskeleton processing in the sustainable circular economy and applied blue bioeconomy—most notably for adsorbent materials for pollutants dissolved in water or as ordered, nature-derived nanostructured templates.

Rutin (RUT) is considered one the most attractive flavonoids from a therapeutic perspective due to its multispectral pharmacological activities including antiradical, anti-inflammatory, antiproliferative, and antimetastatic among others. Still, this compound presents a low bioavailability what narrows its clinical applications. To overcome this inconvenience, the current paper was focused on the synthesis, characterization, and toxicological assessment of two RUT bioconjugates obtained by enzymatic esterification with oleic acid (OA) and linoleic acid (LA)—rutin oleate (RUT-O) and rutin linoleate (RUT-L), as flavonoid precursors with improved physicochemical and biological properties. Following the enzymatic synthesis in the presence of Novozyme® 435, the two bioconjugates were obtained, their formation being confirmed by RAMAN and FT-IR spectroscopy. The in vitro and in ovo toxicological assessment of RUT bioconjugates (1–100 µM) was performed using 2D consecrated cell lines (cardiomyoblasts - H9c2(2-1), hepatocytes—HepaRG, and keratinocytes—HaCaT), 3D reconstructed human epidermis tissue (EpiDerm™), and chick chorioallantoic membranes, respectively. The results obtained were test compound, concentration—and cell-type dependent, as follows: RUT-O reduced the viability of H9c2(2-1), HepaRG, and HaCaT cells at 100 µM (to 77.53%, 83.17%, and 78.32%, respectively), and induced cell rounding and floating, as well as apoptotic-like features in the nuclei of all cell lines, whereas RUT-L exerted no signs of cytotoxicity in all cell lines in terms of cell viability, morphology, and nuclear integrity. Both RUT esters impaired the migration of HepaRG cells (at 25 µM) and lack irritative potential (at 100 µM) in vitro (tissue viability >50%) and in ovo (irritation scores of 0.70 for RUT-O, and 0.49 for RUT-L, respectively). Computational predictions revealed an increased lipophilicity, and reduced solubility, drug-likeness and drug score of RUT-O and RUT-L compared to their parent compounds—RUT, OA, and LA. In conclusion, we report a favorable toxicological profile for RUT-L, while RUT-O is dosage-limited since at high concentrations were noticed cytotoxic effects.