Aluminum-Free Borosilicate Glass Functionalized Hydrogels for Enhanced Dental Tissue Regeneration.

Hydrogels are promising scaffolds for tissue regeneration, and borosilicate glass particles have demonstrated potential in enhancing the biological behaviour of dental pulp cells. However, the specific morphological characteristics of dental lesions and the diverse requirements of dental tissues require biocompatible, bioactive, and shapeable scaffolds. This study aimed to evaluate the in vitro biological behaviour of human gingival fibroblasts (HGFs) in contact with an experimental aluminum-free borosilicate glass-functionalized hydrogel.

Synthetic injectable and porous hydrogels for the formation of skeletal muscle fibers: Novel perspectives for the acellular repair of substantial volumetric muscle loss.

In severe skeletal muscle damage, muscle tissue regeneration process has to face the loss of resident muscle stem cells (MuSCs) and the lack of connective tissue necessary to guide the regeneration process. Biocompatible and standardized 3D structures that can be injected to the muscle injury site, conforming to the defect shape while actively guiding the repair process, holds great promise for skeletal muscle tissue regeneration. In this study, we explore the use of an injectable and porous lysine dendrimer/polyethylene glycol (DGL/PEG) hydrogel as an acellular support for skeletal muscle regeneration.

Method for Large-scale Production of hIPSC Spheroids.

Stem cell spheroids are rapidly becoming essential tools for a diverse array of applications ranging from tissue engineering to 3D cell models and fundamental biology. Given the increasing prominence of biotechnology, there is a pressing need to develop more accessible, efficient, and reproducible methods for producing these models. Various techniques such as hanging drop, rotating wall vessel, magnetic levitation, or microfluidics have been employed to generate spheroids.

An innovative Fuller's earth-based film-forming formulation for skin decontamination, through removal and entrapment of an organophosphorus compound, paraoxon-ethyl.

Organophosphorus compounds (OPs), such as VX, pose a significant threat due to their neurotoxic and hazardous properties. Skin decontamination is essential to avoid irreversible effects. Fuller's earth (FE), a phyllosilicate conventionally employed in powder form, has demonstrated decontamination capacity against OPs.

Human Induced Pluripotent Spheroids' Growth Is Driven by Viscoelastic Properties and Macrostructure of 3D Hydrogel Environment.

Stem cells, particularly human iPSCs, constitute a powerful tool for tissue engineering, notably through spheroid and organoid models. While the sensitivity of stem cells to the viscoelastic properties of their direct microenvironment is well-described, stem cell differentiation still relies on biochemical factors. Our aim is to investigate the role of the viscoelastic properties of hiPSC spheroids' direct environment on their fate.

Versatile fiber-reinforced hydrogels to mimic the microstructure and mechanics of human vocal-fold upper layers.

Human vocal folds are remarkable soft laryngeal structures that enable phonation due to their unique vibro-mechanical performances. These properties are tied to their specific fibrous architecture, especially in the upper layers, which comprise a gel-like composite called lamina propria. The lamina propria can withstand large and reversible deformations under various multiaxial loadings.

Osteogenic Potential of a Polyethylene Glycol Hydrogel Functionalized with Poly-Lysine Dendrigrafts (DGL) for Bone Regeneration.

Resorbable hydrogels are widely used as scaffolds for tissue engineering. These hydrogels can be modified by grafting dendrimer-linked functionalized molecules (dendrigrafts). Our aim was to develop a tunable poly(L-lysine) dendrigrafts (DGL)/PEG-based hydrogel with an inverse porosity and to investigate its osteogenic potential.

Aqueous suspensions of Fuller's earth potentiate the adsorption capacities of paraoxon and improve skin decontamination properties.

Fuller's earth (FE) is a phyllosilicate used as a powder for household or skin decontamination due to its adsorbent properties. Recent studies have shown that water suspensions exhibit similar adsorbent capacities. FE is heterogeneous due to its composition of elementary clay aggregates and heavy metal particles.

Design and characterization of an in vivo injectable hydrogel with effervescently generated porosity for regenerative medicine applications.

Injectable hydrogels that polymerize directly in vivo hold significant promises in clinical settings to support the repair of damaged or failing tissues. Existing systems that allow cellular and tissue ingrowth after injection are limited because of deficient porosity and lack of oxygen and nutrient diffusion inside the hydrogels. Here is reported for the first time an in vivo injectable hydrogel in which the porosity does not pre-exist but is formed concomitantly with its in situ injection by a controlled effervescent reaction.

Versatile lysine dendrigrafts and polyethylene glycol hydrogels with inherent biological properties: in vitro cell behavior modulation and in vivo biocompatibility.

Poly(ethylene glycol) (PEG) hydrogels have been extensively used as scaffolds for tissue engineering applications, owing to their biocompatibility, chemical versatility, and tunable mechanical properties. However, their bio-inert properties require them to be associated with additional functional moieties to interact with cells. To circumvent this need, we propose here to reticulate PEG molecules with poly(L-lysine) dendrigrafts (DGL) to provide intrinsic cell functionalities to PEG-based hydrogels.

Combination of biocompatible hydrogel precursors to apatitic calcium phosphate cements (CPCs): Influence of the in situ hydrogel reticulation on the CPC properties.

In the field of bone regenerative medicine, injectable calcium phosphate cements (CPCs) are used for decades in clinics, as bone void fillers. Most often preformed polymers (e.g.

Adult Stem Cells Spheroids to Optimize Cell Colonization in Scaffolds for Cartilage and Bone Tissue Engineering.

Top-down tissue engineering aims to produce functional tissues using biomaterials as scaffolds, thus providing cues for cell proliferation and differentiation. Conversely, the bottom-up approach aims to precondition cells to form modular tissues units (building-blocks) represented by spheroids. In spheroid culture, adult stem cells are responsible for their extracellular matrix synthesis, re-creating structures at the tissue level.

Sustained spatiotemporal release of TGF-β1 confers enhanced very early chondrogenic differentiation during osteochondral repair in specific topographic patterns.

The continuous presence of TGF-β is critically important to induce effective chondrogenesis. To investigate chondrogenesis in a cartilage defect, we tested the hypothesis that the implantation of TGF-β1-releasing scaffolds improves very early cartilage repair in vivo. Spatiotemporal controlled release of TGF-β1 was achieved from multiblock scaffolds that were implanted in osteochondral defects in the medial femoral condyles of adult minipigs.

Antibiotic incorporation in jet-sprayed nanofibrillar biodegradable scaffolds for wound healing.

In view of preparing antibiotic-loaded structures that can be used as dressing to prevent or contain wound infections, this study evaluates biodegradable nanofibrillar matrices obtained by jet-spraying and containing ciprofloxacin (CIF). The matrices were prepared from different blends of poly-(ε-caprolactone) (PCL) and poly-d,l-(lactic acid) (PDLLA) in view of controlling mechanical properties, biodegradation and antibiotic release rate. The effect of CIF incorporation was assessed in regard of matrices fiber diameter, mechanical properties and degradation while antibiotic release from the polymer blends of different PCL/PDLLA ratios was measured in buffers of different pH to better mimic the wound context.

A Strategy to Enhance Secretion of Extracellular Matrix Components by Stem Cells: Relevance to Tissue Engineering.

The ability of cells to secrete extracellular matrix proteins is an important property in the repair, replacement, and regeneration of living tissue. Cells that populate tissue-engineered constructs need to be able to emulate these functions. The motifs, KTTKS or palmitoyl-KTTKS (peptide amphiphile), have been shown to stimulate production of collagen and fibronectin in differentiated cells.

Controlled association and delivery of nanoparticles from jet-sprayed hybrid microfibrillar matrices.

To develop bioactive scaffolds of targeted properties for tissue repair or biomedical applications, hybrid microfiber-nanoparticle (MF-NP) matrices capable of controlled nanoparticle (NP) delivery were prepared through two novel approaches. In a first strategy, the suppleness of the jet-spraying method to produce polymer microfibers (MF) was used to deposit poly(d,l-lactide) (PLA) NP on poly(lactic-co-glycolic acid) (PLGA) MF by direct co-projection. The second approach relied on the post-incubation of PLA NP aqueous dispersion with MF preliminarily prepared by jet-spraying.

Adapted chondrogenic differentiation of human mesenchymal stem cells via controlled release of TGF-β1 from poly(ethylene oxide)-terephtalate/poly(butylene terepthalate) multiblock scaffolds.

Controlled release of TGF-β1 from scaffolds is an attractive mechanism to modulate the chondrogenesis of human bone marrow mesenchymal stem cells (hBMSCs) that repopulate articular cartilage defects. Here, we evaluated the ability of porous scaffolds composed of poly(ethylene oxide)-terephtalate and poly(butylene terepthalate) (PEOT/PBT) to release bioactive TGF-β1 for chondrogenesis of hBMSCs in a pellet culture model. Chondroinduction was compared with that promoted by direct addition of the recombinant factor to the culture medium.

The potential of anisotropic matrices as substrate for heart valve engineering.

Cells environment is increasingly recognized as an important function regulator through cell-matrix interactions. Extracellular matrix (ECM) anisotropy being a key component of heart valves properties, we have devised a method to create highly porous anisotropic nanofibrillar scaffolds and studied their suitability as cell-support and interactions with human adipose derived stem cells (hADSCs) and human valve interstitial cells (hVICs). Anisotropic nanofibrillar scaffolds were produced by a modified jet-spraying method that allows the formation of aligned nanofibres (600 nm) through air-stream diffraction of a polymer solution (poly (ε-caprolactone, PCL) and collection onto a variably rotating drum.

Novel and simple alternative to create nanofibrillar matrices of interest for tissue engineering.

Synthetic analogs to natural extracellular matrix (ECM) at the nanometer level are of great potential for regenerative medicine. This study introduces a novel and simple method to produce polymer nanofibers and evaluates the properties of the resulting structures, as well as their suitability to support cells and their potential interest for bone and vascular applications. The devised approach diffracts a polymer solution by means of a spraying apparatus and of an airstream as sole driving force.

Osteoblastic differentiation and potent osteogenicity of three-dimensional hBMSC-BCP particle constructs.

Bone tissue engineering usually consists of associating osteoprogenitor cells and macroporous scaffolds. This study investigated the in vitro osteoblastic differentiation and resulting in vivo bone formation induced by a different approach that uses particles as substrate for human bone marrow stromal cells (hBMSCs), in order to provide cells with a higher degree of freedom and allow them to synthesize a three-dimensional (3D) environment. Biphasic calcium phosphate (BCP) particles (35 mg, ~175 µm in diameter) were therefore associated with 4 × 10(5) hBMSCs.

Consistent osteoblastic differentiation of human mesenchymal stem cells with bone morphogenetic protein 4 and low serum.

Providing fully mature and functional osteoblasts is challenging for bone tissue engineering and regenerative medicine. Such cells could be obtained from multipotent bone marrow mesenchymal stem cells (MSCs) after induction by different osteogenic factors. However, there are some discrepancies in results, notably due to the use of sera and to the type of osteogenic factor.

Macrophage and osteoblast responses to biphasic calcium phosphate microparticles.

The aim of this work was to investigate in vitro the biological events leading to ectopic bone formation in contact with microporous biphasic calcium phosphate (BCP) ceramics. After implantation, microparticles may arise from their degradation and induce an inflammatory response involving macrophages. The secretion of pro-inflammatory cytokines may affect the differentiation of osteoblasts.

The human nose harbors a niche of olfactory ectomesenchymal stem cells displaying neurogenic and osteogenic properties.

We previously identified multipotent stem cells within the lamina propria of the human olfactory mucosa, located in the nasal cavity. We also demonstrated that this cell type differentiates into neural cells and improves locomotor behavior after transplantation in a rat model of Parkinson's disease. Yet, next to nothing is known about their specific stemness characteristics.

Porous beta tricalcium phosphate scaffolds used as a BMP-2 delivery system for bone tissue engineering.

Macroporous beta tricalcium phosphate (beta-TCP) scaffolds were evaluated as potential carriers and delivery systems for bone morphogenetic protein-2 (BMP-2). Chemical etching was performed to increase the available surface and thus the protein loading. X-ray diffraction and infrared spectrocopy analyses confirmed the preparation of pure beta-TCP scaffolds.

Rapid prototyped porous titanium coated with calcium phosphate as a scaffold for bone tissue engineering.

High strength porous scaffolds and mesenchymal stem cells are required for bone tissue engineering applications. Porous titanium scaffolds (TiS) with a regular array of interconnected pores of 1000 microm in diameter and a porosity of 50% were produced using a rapid prototyping technique. A calcium phosphate (CaP) coating was applied to these titanium (Ti) scaffolds with an electrodeposition method.