Bone Spheroid Development Under Flow Conditions with Mesenchymal Stem Cells and Human Umbilical Vein Endothelial Cells in a 3D Porous Hydrogel Supplemented with Hydroxyapatite.

Understanding the niche interactions between blood and bone through the in vitro co-culture of osteo-competent cells and endothelial cells is a key factor in unraveling therapeutic potentials in bone regeneration. This can be additionally supported by employing numerical simulation techniques to assess local physical factors, such as oxygen concentration, and mechanical stimuli, such as shear stress, that can mediate cellular communication. In this study, we developed a Mesenchymal Stem Cell line (MSC) and a Human Umbilical Vein Endothelial Cell line (HUVEC), which were co-cultured under flow conditions in a three-dimensional, porous, natural pullulan/dextran scaffold that was supplemented with hydroxyapatite crystals that allowed for the spontaneous formation of spheroids.

Injectable bone cement containing carboxymethyl cellulose microparticles as a silver delivery system able to reduce implant-associated infection risk.

In the challenging quest for a solution to reduce the risk of implant-associated infections in bone substitution surgery, the use of silver ions is promising regarding its broad spectrum on planktonic, sessile as well as multiresistant bacteria. In view of controlling its delivery in situ at the desired dose, we investigated its encapsulation in carboxymethyl cellulose (CMC) microparticles by spray-drying and included the latter in the formulation of a self-setting calcium phosphate bone cement. We implemented an original step-by-step methodology starting from the in vitro study of the antibacterial properties and cytotoxicity of two silver salts of different solubility in aqueous medium and then in the cement to determine the range of silver loading able to confer anti-biofilm and non-cytotoxic properties to the biomaterial.

Assessment of fresh and preserved amniotic membrane for guided bone regeneration in mice.

Thanks to its biological properties, the human amniotic membrane (HAM) can be used as a barrier membrane for guided bone regeneration (GBR). However, no study has assessed the influence of the preservation method of HAM for this application. This study aimed to establish the most suitable preservation method of HAM for GBR.

Layer-by-layer bioassembly of poly(lactic) acid membranes loaded with coculture of HBMSCs and EPCs improves vascularization in vivo.

Layer-by-layer (LBL) BioAssembly method was developed to enhance the control of cell distribution within 3D scaffolds for tissue engineering applications. The objective of this study was to evaluate in vivo the development of blood vessels within LBL bioassembled membranes seeded with human primary cells, and to compare it to cellularized massive scaffolds. Poly(lactic) acid (PLA) membranes fabricated by fused deposition modeling were seeded with monocultures of human bone marrow stromal cells or with cocultures of these cells and endothelial progenitor cells.

Towards an in vitro model of the glomerular barrier unit with an innovative bioassembly method.

Background: The development of an artificial glomerular unit may be pivotal for renal pathophysiology studies at a multicellular scale. Using a tissue engineering approach, we aimed to reproduce in part the specific glomerular barrier architecture by manufacturing a glomerular microfibre (Mf).

Methods: Immortalized human glomerular cell lines of endothelial cells (GEnCs) and podocytes were used.

Injectable and Gellable Chitosan Formulations Filled with Cellulose Nanofibers for Intervertebral Disc Tissue Engineering.

The development of non-cellularized injectable suspensions of viscous chitosan (CHI) solutions (1.7⁻3.3% (/)), filled with cellulose nanofibers (CNF) (0.

Cell and tissue responses at the interface with a chitosan hydrogel intended for vascular applications: in vitro and in vivo exploration.

Aims: The need for small caliber vessels to treat cardiovascular diseases has grown. However, synthetic polymers perform poorly in small-diameter applications. Chitosan hydrogels can provide a novel biological scaffold for vascular engineering.

Influence of the three-dimensional culture of human bone marrow mesenchymal stromal cells within a macroporous polysaccharides scaffold on Pannexin 1 and Pannexin 3.

Because cell interactions play a fundamental role for cell differentiation, we investigated the expression of Pannexin 1 and Pannexin 3 in human bone marrow mesenchymal stromal cells (HBMSCs) in a three-dimensional (3D) microenvironment provided by a polysaccharide-based macroporous scaffold. The pannexin (Panx) family consists of three members, Panx1, Panx2, and Panx3. The roles of Panx large-pore ion and metabolite channels are recognized in many physiological and pathophysiological scenarios, but the role of these proteins in human physiological processes is still under investigation.

Prolonged delivery of BMP-2 by a non-polymer hydrogel for bone defect regeneration.

Bone morphogenetic protein 2 (BMP-2) is a potent inducer of bone formation that is currently used in a limited number of clinical indications to treat extensive bone loss. Extending the field of applications of this molecule requires design of the delivery system to protect the protein from early degradation and allow a slow long-term release. This study describes the use of a non-polymer hydrogel, based on the self-assembly of small amphiphilic glycosyl-nucleolipids into micellar structures, as a new type of delivery system for BMP-2.

Colorectal wall regeneration resulting from the association of chitosan hydrogel and stromal vascular fraction from adipose tissue.

Chitosan hydrogel and adipose derived stem cells (ADCS) have been reported as the optimal partnership for colorectal tissue engineering. In that field, the aim of the current experiment was to assess the interest of seeding ADSC on chitosan hydrogel patches in an in vivo comparative study and on a tube intended replace a colonic segment in an in vivo feasibility study. In the comparative study, a 2 × 3 cm colonic wall defect was performed in 20 swine and repaired by suturing a chitosan hydrogel patch: acellular matrix (group A, n = 10) versus matrix seeded with autologous stromal vascular fraction (SVF) (group B, n = 10).

A new composite hydrogel combining the biological properties of collagen with the mechanical properties of a supramolecular scaffold for bone tissue engineering.

Tissue engineering is a promising alternative to autografts, allografts, or biomaterials to address the treatment of severe and large bone lesions. Classically, tissue engineering products associate a scaffold and cells and are implanted or injected into the lesion. These cells must be embedded in an appropriate biocompatible scaffold, which offers a favourable environment for their survival and differentiation.

Layer-by-layer bioassembly of cellularized polylactic acid porous membranes for bone tissue engineering.

The conventional tissue engineering is based on seeding of macroporous scaffold on its surface ("top-down" approach). The main limitation is poor cell viability in the middle of the scaffold due to poor diffusion of oxygen and nutrients and insufficient vascularization. Layer-by-Layer (LBL) bioassembly is based on "bottom-up" approach, which considers assembly of small cellularized blocks.

The proangiogenic potential of a novel calcium releasing composite biomaterial: Orthotopic in vivo evaluation.

Unlabelled: Insufficient angiogenesis remains a major hurdle in current bone tissue engineering strategies. An extensive body of work has focused on the use of angiogenic factors or endothelial progenitor cells. However, these approaches are inherently complex, in terms of regulatory and methodologic implementation, and present a high cost.

An easy-to-use and versatile method for building cell-laden microfibres.

Fibre-shaped materials are useful for creating different functional three-dimensional (3D) structures that could mimic complex tissues. Several methods (e.g.

The proangiogenic potential of a novel calcium releasing biomaterial: Impact on cell recruitment.

Unlabelled: In current bone tissue engineering strategies the achievement of sufficient angiogenesis during tissue regeneration is still a major limitation in order to attain full functionality. Several strategies have been described to tackle this problem, mainly by the use of angiogenic factors or endothelial progenitor cells. However, when facing a clinical scenario these approaches are inherently complex and present a high cost.

Colorectal tissue engineering: A comparative study between porcine small intestinal submucosa (SIS) and chitosan hydrogel patches.

Objective: Tissue engineering may provide new operative tools for colorectal surgery in elective indications. The aim of this study was to define a suitable bioscaffold for colorectal tissue engineering.

Methods: We compared 2 bioscaffolds with in vitro and in vivo experiments: porcine small intestinal submucosa (SIS) versus chitosan hydrogel matrix.

Labeling and qualification of endothelial progenitor cells for tracking in tissue engineering: An in vitro study.

Purpose: In order to track location and distribution of endothelial cells (ECs) within scaffolds in vitro, we chose lentiPGK-TdTomato transduction of human endothelial progenitor cells (EPCs) isolated and differentiated from cord blood. Because transduction could have a functional impact on cell behavior, we checked different parameters for qualification of labeled- EPCs as well as their use for potential applications in the context of vascular and bone tissue engineering.

Methods: After isolation and expansion, EPCs were classically characterized then transduced with the lentiviral vector containing the TdTomato protein gene under the control of the phosphoglycerate kinase (PGK) promoter.

The use of total human bone marrow fraction in a direct three-dimensional expansion approach for bone tissue engineering applications: focus on angiogenesis and osteogenesis.

Current approaches in bone tissue engineering have shown limited success, mostly owing to insufficient vascularization of the construct. A common approach consists of co-culture of endothelial cells and osteoblastic cells. This strategy uses cells from different sources and differentiation states, thus increasing the complexity upstream of a clinical application.

Physicochemical modulation of chitosan-based hydrogels induces different biological responses: interest for tissue engineering.

Polysaccharide-based hydrogels are remarkable materials for the development of tissue engineering strategies as they meet several critical requirements for such applications and they may partly mimic the extracellular matrix. Chitosan is widely envisioned as hydrogel in biomedical fields for its bioresorbability, biocompatibility, and fungistatic and bacteriostatic properties. In this study, we report that the modulation of the polymer concentration, the degree of acetylation, the gelation processes [or neutralization routes (NR)] in the preparation of different chitosan-based hydrogels lead to substantially and significantly different biological responses.

Composition and properties of silver-containing calcium carbonate-calcium phosphate bone cement.

The introduction of silver, either in the liquid phase (as silver nitrate solution: Ag(L)) or in the solid phase (as silver phosphate salt: Ag(S)) of calcium carbonate-calcium phosphate (CaCO3-CaP) bone cement, its influence on the composition of the set cement (C-Ag(L) and C-Ag(S) cements with a Ca/Ag atomic ratio equal to 10.3) and its biological properties were investigated. The fine characterisation of the chemical setting of silver-doped and reference cements was performed using FTIR spectroscopy.

A nano-hydroxyapatite--pullulan/dextran polysaccharide composite macroporous material for bone tissue engineering.

Research in bone tissue engineering is focused on the development of alternatives to allogenic and autologous bone grafts that can stimulate bone healing. Here, we present scaffolds composed of the natural hydrophilic polysaccharides pullulan and dextran, supplemented or not with nanocrystalline hydroxyapatite particles (nHA). In vitro studies revealed that these matrices induced the formation of multicellular aggregates and expression of early and late bone specific markers with human bone marrow stromal cells in medium deprived of osteoinductive factors.