Model-Based Design to Enhance Neotissue Formation in Additively Manufactured Calcium-Phosphate-Based Scaffolds.

In biomaterial-based bone tissue engineering, optimizing scaffold structure and composition remains an active field of research. Additive manufacturing has enabled the production of custom designs in a variety of materials. This study aims to improve the design of calcium-phosphate-based additively manufactured scaffolds, the material of choice in oral bone regeneration, by using a combination of in silico and in vitro tools.

Biological performance of a novel bovine hydroxyapatite in a guided bone regeneration model: A preclinical study in a mandibular defect in dogs.

Objectives: This preclinical model study aims to evaluate the performance and safety of a novel hydroxyapatite biomaterial (Wishbone Hydroxyapatite, WHA) on guided bone regeneration compared to a commercially available deproteinized bovine bone mineral (Bio-Oss, BO).

Material And Methods: Twenty-four beagle dogs were allocated to three timepoint cohorts (4, 12, and 26 weeks) of eight animals each. In all animals, four critical-sized, independent wall mandibular defects were created (32 defects/cohort).

Pancreatic and intestinal endocrine cells in zebrafish share common transcriptomic signatures and regulatory programmes.

Background: Endocrine cells of the zebrafish digestive system play an important role in regulating metabolism and include pancreatic endocrine cells (PECs) clustered in the islets of Langerhans and the enteroendocrine cells (EECs) scattered in the intestinal epithelium. Despite EECs and PECs are being located in distinct organs, their differentiation involves shared molecular mechanisms and transcription factors. However, their degree of relatedness remains unexplored.

Ascl1b and Neurod1, instead of Neurog3, control pancreatic endocrine cell fate in zebrafish.

Background: NEUROG3 is a key regulator of pancreatic endocrine cell differentiation in mouse, essential for the generation of all mature hormone producing cells. It is repressed by Notch signaling that prevents pancreatic cell differentiation by maintaining precursors in an undifferentiated state.

Results: We show that, in zebrafish, neurog3 is not expressed in the pancreas and null neurog3 mutant embryos do not display any apparent endocrine defects.

The bHLH transcription factor Ascl1a is essential for the specification of the intestinal secretory cells and mediates Notch signaling in the zebrafish intestine.

Notch signaling has a fundamental role in stem cell maintenance and in cell fate choice in the intestine of different species. Canonically, Notch signaling represses the expression of transcription factors of the achaete-scute like (ASCL) or atonal related protein (ARP) families. Identifying the ARP/ASCL genes expressed in the gastrointestinal tract is essential to build the regulatory cascade controlling the differentiation of gastrointestinal progenitors into the different intestinal cell types.