Langstondickson1749

Synthetic scaffolds exhibiting bone repair ability equal to that of autogenous bone are required in the fields of orthopedics and dentistry. A suitable synthetic bone graft substitute should induce osteogenic differentiation of mesenchymal stem cells, osteogenesis, and angiogenesis. In this study, three types of honeycomb blocks (HCBs), composed of hydroxyapatite (HAp), β-tricalcium phosphate (TCP), and carbonate apatite (CO3Ap), were fabricated, and the effects of HCB composition on bone formation and maturation were investigated. The HC structure was selected to promote cell penetration and tissue ingrowth. HAp and β-TCP HCBs were fabricated by extrusion molding followed by sintering. The CO3Ap HCBs were fabricated by extrusion molding followed by sintering and dissolution-precipitation reactions. These HCBs had similar macroporous structures all harbored uniformly distributed macropores (∼160 ​μm) that were regularly arrayed and penetrated the blocks unidirectionally. Moreover, the volumes of macropores weosteoclasts. Besides the composition, the microporous structure of HC struts, inevitably generated during the formation of HCBs of various compositions, may contribute to the differences in bone maturation and formation. © 2019 The Authors.The intestine is a highly heterogeneous hollow organ with biological, mechanical and chemical differences between lumen and wall. A functional human intestine model able to recreate the in vivo dynamic nature as well as the native tissue morphology is demanded for disease research and ​drug discovery. Here, we present a system, which combines an engineered three-dimensional (3D) tubular-shaped intestine model (3D In-tube) with a custom-made microbioreactor to impart the key aspects of the in vivo microenvironment of the human intestine, mimicking the rhythmic peristaltic movement. We adapted a previously established bottom-up tissue engineering approach, to produce the 3D tubular-shaped lamina propria and designed a glass microbioreactor to induce the air-liquid interface ​condition and peristaltic-like motion. Our results demonstrate the production of a villi-like protrusion and a correct spatial differentiation of the intestinal epithelial cells in enterocyte-like as well as mucus-producing-like cells on the lumen side of the 3D In-tube. This dynamic platform offers a proof-of-concept model of the human intestine. © 2019 The Author(s).In bottom-up tissue engineering, small modular units of cells and biomaterials are assembled toward ​larger and more complex ones. In conjunction with a new implementation of this approach, a novel method to fabricate microscale objects from biopolymers by thermal imprinting on water-soluble sacrificial layers is presented. By this means, geometrically well-defined objects could be obtained without involving toxic agents in the form of photoinitiators. The micro-objects were used as cell-adhesive substrates and cell spacers in engineered tissues created by cell-guided assembly of the objects. Such constructs can be applied both for in vitro studies and clinical treatments. Clinically relevantly sized aggregates comprised of cells and micro-objects retained their viability up to 2 weeks of culture. The aggregation behavior of cells and objects showed to depend on the type and number of cells applied. To demonstrate the micro-objects' potential for engineering vascularized tissues, small aggregates of human bone marrow stromal cells (hMSCs) and micro-objects were coated with a layer of human umbilical vein endothelial cells (HUVECs) and fused into larger tissue constructs, resulting in HUVEC-rich regions at the aggregates' interfaces. This three-dimensional network-type spatial cellular organization could foster the establishment of (premature) vascular structures as a vital prerequisite of, for example, bottom-up-engineered bone-like tissue. © 2019 The Authors.In this work, we describe a microfluidic three-dimensional (3D) chondrocyte culture mimicking in vivo articular chondrocyte morphology, cell distribution, metabolism, and gene expression. This has been accomplished by establishing a physiologic nutrient diffusion gradient across the simulated matrix, while geometric design constraints of the microchambers drive native-like cellular behavior. Primary equine chondrocytes remained viable for the extended culture time of 3 weeks and maintained the low metabolic activity and high Sox9, aggrecan, and Col2 expression typical of articular chondrocytes. Our microfluidic 3D chondrocyte microtissues were further exposed to inflammatory cytokines to establish an animal-free, in vitro osteoarthritis model. Results of our study indicate that our microtissue model emulates the basic characteristics of native cartilage and responds to biochemical injury, thus providing a new foundation for exploration of osteoarthritis pathophysiology in both human and veterinary patients. © 2019 The Authors.Unlike the central nervous system, peripheral nerves can regenerate after injury. However, depending on the size of the lesion, the endogenous regenerative potential is not enough to replace the lost nerve tissue. Many strategies have been used to generate biomaterials capable of restoring nerve functions. Here, we set out to investigate whether adsorbing the extracellular matrix protein, laminin (LM), to poly-ℇ-caprolactone (PCL) filaments would enhance functional nerve regeneration. Initial in vitro studies showed that explants of dorsal root ganglia (DRGs) of P1 neonate mice exhibited stronger neuritogenesis on a substrate of LM that had been previously polymerized (polylaminin [polyLM]) than on ordinary LM. On the other hand, when silicone tubes filled with PCL filaments were used to bridge a 10-mm sciatic nerve gap in rats, only filaments coated with LM improved tissue replacement beyond that obtained with empty tubes. selleckchem Motor function recovery correlated with tissue replacement as only LM-coated filaments consistently improved motor skills. Finally, analysis of the lateral gastrocnemius muscle revealed that the LM group presented twice the amount of α-bungarotixin-labeled motor plates. In conclusion, although polyLM was more effective in stimulating growth of sensory fibers out of DRGs in vitro, LM adsorbed to PCL filaments exhibited the best regenerative properties in inducing functional motor recovery after peripheral injury in vivo. © 2019 Published by Elsevier Ltd.