Search

Hemophilia A (HA) cell therapy approaches in pediatric individuals require suitable factor (F)VIII-producing cells for stable engraftment. Liver sinusoidal endothelial cells (LSEC) and hematopoietic stem cells (HSC) have been demonstrated to be suitable for the treatment of adult HA mice. However, after transplantation in busulfan (BU)-conditioned newborn mice, adult LSEC/HSC cannot efficiently engraft, while murine fetal liver (FL) hemato/vascular cells from embryonic day 11-13 of gestation (E11-E13), strongly engraft the hematopoietic and endothelial compartments while also secreting FVIII. Our aim was to investigate the engraftment of FL cells in newborn HA mice to obtain a suitable “proof of concept” for the development of a new HA treatment in neonates. Hence, we transplanted FL E11 or E13 cells and adult bone marrow (BM) cells into newborn HA mice with or without BU preconditioning. Engraftment levels and FVIII activity were assessed starting from 6 weeks after transplantation. FL E11-E13+ BU transplanted newborns reached up to 95% engraftment with stable FVIII activity levels observed for 16 months. FL E13 cells showed engraftment ability even in the absence of BU preconditioning, while FL E11 cells did not. BM BU transplanted newborn HA mice showed high levels of engraftment; nevertheless, in contrast to FL cells, BM cells cannot engraft HA newborns in BU non-conditioning regimen. Finally, none of the transplanted mice developed anti-FVIII antibodies. Overall, this study sheds some light on the therapeutic potential of healthy FL cells in the cure of HA neonatal/pediatric patients.

The eggshell is a biomineral consisting of CaCO3 in the form of calcite phase and a pervading organic matrix (1–3.5 wt.%). Transforming eggshell calcite particles into calcium phosphate (apatite) micro-nanoparticles opens the door to repurposing the eggshell waste as materials with potential biomedical applications, fulfilling the principles of the circular economy. Previous methods to obtain these particles consisted mainly of two steps, the first one involving the calcination of the eggshell. In this research, direct transformation by a one-pot hydrothermal method ranging from 100–200 °C was studied, using suspensions with a stoichiometric P/CaCO3 ratio, K2HPO4 as P reagent, and eggshells particles (Ø < 50 μm) both untreated and treated with NaClO to remove surface organic matter. In the untreated group, the complete conversion was achieved at 160 °C, and most particles displayed a hexagonal plate morphology, eventually with a central hole. In the treated group, this replacement occurred at 180 °C, yielding granular (spherulitic) apatite nanoparticles. The eggshell particles and apatite micro-nanoparticles were cytocompatible when incubated with MG-63 human osteosarcoma cells and m17.ASC murine mesenchymal stem cells and promoted the osteogenic differentiation of m17.ASC cells. The study results are useful for designing and fabricating biocompatible microstructured materials with osteoinductive properties for applications in bone tissue engineering and dentistry.

Oyster shell wastes from the fishing industry represent a major environmental problem, as 7 million Tm/year are produced with no efficient recycling [1]. They are composed of Mgcalcite embedded in an organic matrix formed of proteins and polysaccharides. On the other hand, nanocrystalline apatites (NAp), which are structural and compositional analogues to the major inorganic component of human bones, exhibit excellent bioactivity and biocompatibility, and present a broad range of applications in hard tissue engineering, biomedicine, drug-delivery system and even in analytical sciences [2]. In this work, biogenic calcite from oyster shells was used to obtain apatite NPs by a ¿one-pot¿ hydrothermal process. Eu3+ and Tb3+ ions were added to the formulation to obtain Eu3+- and Tb3+-doped apatite NPs with luminescent properties. Solid-state characterization of the nanoparticles was performed by powder X-ray diffraction (PXRD), FT-IR and Raman spectroscopy, SEM and TEM microscopy, dynamic light scattering (DLS) and inductively coupled plasma (ICP) spectrometry, while luminescence properties were evaluated by luminescent spectroscopy. Finally, the biological behaviour of the NPs was evaluated by cytotoxicity and osteogenic differentiation assays, in murine mesenchymal (M17.1) and murine endothelial (MS-1) cells. Results demonstrated the efficiency of this novel ¿one pot¿ hydrothermal process to obtain nanoparticles of apatite with improved luminescent properties, while, in vitro assays demonstrated the excellent cytocompatibility and the impact of the metal-doping over the osteogenic differentiation capacity of the nanoparticles. Acknowledgment: This work was supported by project PCI2020-112108 funded by MCI/AEI/10.13039/501100011033 (Spain) and the European Union ¿NextGenerationEU¿/PRTR¿. PCI2020-112108 is part of the CASEAWA project of the ERA-NET Cofund BlueBio Programme, supported by the European Union (H2020).

Eggshell (ES) is a biomaterial mainly composed of an inorganic component (CaCO3, calcite phase)and an organic matrix. This material is mostly discarded during food processing cycles. Hydrothermal processing can transform them into calcium phosphate (CaP) salts for industrial and technological applications. This research aims to study the effect of the ES organic matrix during the mineral replacement of CaCO3 into CaP. Additionally, this research explores the biological properties of the resulting CaP particles to determine their potential use for biomedical applications. ES pieces were collected and divided into two groups: untreated ES and ES treated with NaClO for selective removal of the organic component of the material. Subsequently, the ES were milled and sieved into different sizes (50-200 ¿m). The particles were then subjected to hydrothermal treatment using phosphate-bearing solutions at varying temperatures (100°C-200°C) for 7 days. The obtained precipitates were analyzed usi ng scanning electron microscopy (SEM), spectroscopic (ATR-FTIRand Raman), and X-ray diffraction (XRD) techniques. Biological tests were also conducted to evaluate their cytocompatibility on MG-63 human osteosarcoma tumor cells and m17.ASC murine mesenchymal stem cells, as well as the osteogenic differentiation of m17.ASC cells. The CaP particles presented crystallographic and morphological characteristics compatible mainly with the apatite. This conversion occurred differently for the CaCO3 particles in which the organic matrix was preserved, presenting a mineral deposit with hexagonal and nanostructured crystals. Spectroscopic and X-ray diffraction analyses evidenced the control of the organic matrix in the conversion of the ES particles to CaP. The pristine and treated particles were cytocompatible on MG-63 and m17.ASC cells and promoted osteogenic differentiation of m17.ASC cells. In conclusion, the hydrothermal technique allows the conversion of ES particles into CaP phases. The r

We have developed a straightforward, one-pot, low-temperature hydrothermal method to transform oyster shell waste particles (bCCP) from the species Crassostrea gigas (Mg-calcite, 5 wt% Mg) into hydroxyapatite (HA) micro/nanoparticles. The influence of the P reagents (HPO, KHPO, and KHPO), P/bCCP molar ratios (0.24, 0.6, and 0.96), digestion temperatures (25-200 °C), and digestion times (1 week-2 months) on the transformation process was thoroughly investigated. At 1 week, the minimum temperature to yield the full transformation significantly reduced from 160 °C to 120 °C when using KHPO instead of KHPO at a P/bCCP ratio of 0.6, and even to 80 °C at a P/bCCP ratio of 0.96. The transformation took place via a dissolution-reprecipitation mechanism driven by the favorable balance between HA precipitation and bCCP dissolution, due to the lower solubility product of HA than that of calcite at any of the tested temperatures. Both the bCCP and the derived HA particles were cytocompatible for MG-63 human osteosarcoma cells and m17.ASC murine mesenchymal stem cells, and additionally, they promoted the osteogenic differentiation of m17.ASC, especially the HA particles. Because of their physicochemical features and biological compatibility, both particles could be useful osteoinductive platforms for translational applications in bone tissue engineering.