Micromolding-based encapsulation of mesenchymal stromal cells in alginate for intraarticular injection in osteoarthritis.

Osteoarthritis (OA) is an inflammatory joint disease that affects cartilage, subchondral bone, and joint tissues. Undifferentiated Mesenchymal Stromal Cells are a promising therapeutic option for OA due to their ability to release anti-inflammatory, immuno-modulatory, and pro-regenerative factors. They can be embedded in hydrogels to prevent their tissue engraftment and subsequent differentiation.

Injectable Hydrogel Membrane for Guided Bone Regeneration.

In recent years, multicomponent hydrogels such as interpenetrating polymer networks (IPNs) have emerged as innovative biomaterials due to the synergistic combination of the properties of each network. We hypothesized that an innovative non-animal IPN hydrogel combining self-setting silanized hydroxypropyl methylcellulose (Si-HPMC) with photochemically cross-linkable dextran methacrylate (DexMA) could be a valid alternative to porcine collagen membranes in guided bone regeneration. Calvaria critical-size defects in rabbits were filled with synthetic biphasic calcium phosphate granules in conjunction with Si-HPMC; DexMA; or Si-HPMC/DexMA experimental membranes; and in a control group with a porcine collagen membrane.

Comparison of MRI T1, T2, and T2* mapping with histology for assessment of intervertebral disc degeneration in an ovine model.

An easy, reliable, and time-efficient standardized approach for assessing lumbar intervertebral disc (IVD) degeneration with relaxation times measurements in pre-clinical and clinical studies is lacking. This prospective study aims to determine the most appropriate method for lumbar IVD degeneration (IDD) assessment in sheep by comparing three quantitative MRI sequences (variable-flip-angle T1 mapping, and multi-echo T2 and T2* mapping), correlating them with Pfirrmann grading and histology. Strong intra- and interrater agreements were found for Nucleus pulposus (NP) regions-of-interest (ROI).

Development and characterization of a humanized mouse model of osteoarthritis.

Objective: In light of the role of immune cells in OA pathogenesis, the development of sophisticated animal models closely mimicking the immune dysregulation during the disease development and progression could be instrumental for the preclinical evaluation of novel treatments. Among these models, immunologically humanized mice may represent a relevant system, particularly for testing immune-interacting DMOADs or cell therapies before their transfer to the clinic. Our objective, therefore, was to develop an experimental model of OA by destabilization of the medial meniscus (DMM) in humanized mice.

Posttraumatic Osteoarthritis Damage in Mice: From Histological and Micro-Computed Tomodensitometric Changes to Gait Disturbance.

Objectives: Osteoarthritis is a painful joint disease responsible for walking impairment. Its quantitative assessment by gait analysis in mice may be a relevant and noninvasive strategy to assess the disease severity. In this study, we aimed to determine the severity of osteoarthritis at the tissular and gait levels in unilateral and bilateral posttraumatic murine osteoarthritis.

Correlation between magnetic resonance, X-ray imaging alterations and histological changes in an ovine model of age-related disc degeneration.

Sheep are one of the many animal models used to investigate the pathophysiology of disc degeneration and the regenerative strategies for intervertebral disc (IVD) disease. To date, few studies have thoroughly explored ageing of ovine lumbar IVDs. Hence, the objective of the present study was to concomitantly assess the development of spontaneous age-related lumbar IVD degeneration in sheep using X-ray, magnetic resonance imaging (MRI) as well as histological analyses.

Injectable silanized hyaluronic acid hydrogel/biphasic calcium phosphate granule composites with improved handling and biodegradability promote bone regeneration in rabbits.

Biphasic calcium phosphate (BCP) granules are osteoconductive biomaterials used in clinics to favor bone reconstruction. Yet, poor cohesivity, injectability and mechanical properties restrain their use as bone fillers. In this study, we incorporated BCP granules into in situ forming silanized hyaluronic acid (Si-HA) and hydroxypropylmethylcellulose (Si-HPMC) hydrogels.

A partially demineralized allogeneic bone graft: in vitro osteogenic potential and preclinical evaluation in two different intramembranous bone healing models.

In skeletal surgical procedures, bone regeneration in irregular and hard-to-reach areas may present clinical challenges. In order to overcome the limitations of traditional autologous bone grafts and bone substitutes, an extrudable and easy-to-handle innovative partially demineralized allogenic bone graft in the form of a paste has been developed. In this study, the regenerative potential of this paste was assessed and compared to its clinically used precursor form allogenic bone particles.

Silanization of Chitosan and Hydrogel Preparation for Skeletal Tissue Engineering.

Tissue engineering is a multidisciplinary field that relies on the development of customized biomaterial to support cell growth, differentiation and matrix production. Toward that goal, we designed the grafting of silane groups onto the chitosan backbone (Si-chito) for the preparation of in situ setting hydrogels in association with silanized hydroxypropyl methylcellulose (Si-HPMC). Once functionalized, the chitosan was characterized, and the presence of silane groups and its ability to gel were demonstrated by rheology that strongly suggests the presence of silane groups.

Collateral effects of targeting the nucleus pulposus via a transpedicular or transannular surgical route: a combined X-ray, MRI, and histological long-term descriptive study in sheep.

Purpose: In the context of regenerative medicine strategies, based in particular on the injection of regenerative cells, biological factors, or biomaterials into the nucleus pulposus (NP), two main routes are used: the transpedicular approach (TPA) and the transannular approach (TAA). The purpose of our study was to compare the long-term consequences of the TPA and the TAA on intervertebral disc (IVD) health through a longitudinal follow-up in an ovine model.

Methods: The TPA and the TAA were performed on 12 IVDs from 3 sheep.

In Situ Forming, Silanized Hyaluronic Acid Hydrogels with Fine Control Over Mechanical Properties and In Vivo Degradation for Tissue Engineering Applications.

In situ forming hydrogels that can be injected into tissues in a minimally-invasive fashion are appealing as delivery vehicles for tissue engineering applications. Ideally, these hydrogels should have mechanical properties matching those of the host tissue, and a rate of degradation adapted for neo-tissue formation. Here, the development of in situ forming hyaluronic acid hydrogels based on the pH-triggered condensation of silicon alkoxide precursors into siloxanes is reported.

Controlled release of biological factors for endogenous progenitor cell migration and intervertebral disc extracellular matrix remodelling.

The recent description of resident stem/progenitor cells in degenerated intervertebral discs (IVDs) supports the notion that their regenerative capacities could be harnessed to stimulate endogenous repair of the nucleus pulposus (NP). In this study, we developed a delivery system based on pullulan microbeads (PMBs) for sequential release of the chemokine CCL-5 to recruit these disc stem/progenitor cells to the NP tissue, followed by the release of the growth factors TGF-β1 and GDF-5 to induce the synthesis of a collagen type II- and aggrecan-rich extracellular matrix (ECM). Bioactivity of released CCL5 on human adipose-derived stem cells (hASCs), selected to mimic disc stem/progenitors, was demonstrated using a Transwell® chemotaxis assay.

Tailored Three-Dimensionally Printed Triply Periodic Calcium Phosphate Implants: A Preclinical Study for Craniofacial Bone Repair.

Finding alternative strategies for the regeneration of craniofacial bone defects (CSD), such as combining a synthetic ephemeral calcium phosphate (CaP) implant and/or active substances and cells, would contribute to solving this reconstructive roadblock. However, CaP's architectural features (i.e.

A Self-Setting Hydrogel of Silylated Chitosan and Cellulose for the Repair of Osteochondral Defects: From Characterization to Preclinical Evaluation in Dogs.

Articular cartilage (AC) may be affected by many injuries including traumatic lesions that predispose to osteoarthritis. Currently there is no efficient cure for cartilage lesions. In that respect, new strategies for regenerating AC are contemplated with interest.

In vitro and in vivo evaluation of an electrospun-aligned microfibrous implant for Annulus fibrosus repair.

Annulus fibrosus (AF) impairment is associated with reherniation, discogenic pain, and disc degeneration after surgical partial discectomy. Due to a limited intrinsic healing capacity, defects in the AF persist over time and it is hence necessary to adopt an appropriate strategy to close and repair the damaged AF. In this study, a cell-free biodegradable scaffold made of polycaprolactone (PCL), electrospun, aligned microfibers exhibited high levels of cell colonization, alignment, and AF-like extracellular matrix deposition when evaluated in an explant culture model.

In situ photochemical crosslinking of hydrogel membrane for Guided Tissue Regeneration.

Objective: Periodontitis is an inflammatory disease that destroys the tooth-supporting attachment apparatus. Guided tissue regeneration (GTR) is a technique based on a barrier membrane designed to prevent wound space colonization by gingival cells. This study examined a new formulation composed of two polymers that could be photochemically cross-linked in situ into an interpenetrated polymer network (IPN) forming a hydrogel membrane.

Laponite nanoparticle-associated silated hydroxypropylmethyl cellulose as an injectable reinforced interpenetrating network hydrogel for cartilage tissue engineering.

Unlabelled: Articular cartilage is a connective tissue which does not spontaneously heal. To address this issue, biomaterial-assisted cell therapy has been researched with promising advances. The lack of strong mechanical properties is still a concern despite significant progress in three-dimensional scaffolds.

The transpedicular surgical approach for the development of intervertebral disc targeting regenerative strategies in an ovine model.

Purpose: To investigate the suitability of the transpedicular approach (TPA) in a sheep model of IVD regenerative strategies METHODS: 24 IVD from four sheep were used. TPA and biopsies of the Nucleus pulposus (NP) were performed in 18 IVD (6 IVD control). Seven discographies were performed to assess the feasibility of injecting contrast agent.

Olive and grape seed extract prevents post-traumatic osteoarthritis damages and exhibits in vitro anti IL-1β activities before and after oral consumption.

Polyphenols exert a large range of beneficial effects in the prevention of age-related diseases. We sought to determine whether an extract of olive and grape seed standardized according to hydroxytyrosol (HT) and procyanidins (PCy) content, exerts preventive anti-osteoathritic effects. To this aim, we evaluated whether the HT/PCy mix could (i) have in vitro anti-inflammatory and chondroprotective actions, (ii) exert anti-osteoarthritis effects in two post-traumatic animal models and (iii) retain its bioactivity after oral administration.

Longitudinal Comparison of Enzyme- and Laser-Treated Intervertebral Disc by MRI, X-Ray, and Histological Analyses Reveals Discrepancies in the Progression of Disc Degeneration: A Rabbit Study.

Regenerative medicine is considered an attractive prospect for the treatment of intervertebral disc (IVD) degeneration. To assess the efficacy of the regenerative approach, animal models of IVD degeneration are needed. Among these animal models, chemonucleolysis based on the enzymatic degradation of the Nucleus Pulposus (NP) is often used, but this technique remains far from the natural physiopathological process of IVD degeneration.

TGF-β1 and GDF5 Act Synergistically to Drive the Differentiation of Human Adipose Stromal Cells toward Nucleus Pulposus-like Cells.

Degenerative disc disease (DDD) primarily affects the central part of the intervertebral disc namely the nucleus pulposus (NP). DDD explains about 40% of low back pain and is characterized by massive cellular alterations that ultimately result in the disappearance of resident NP cells. Thus, repopulating the NP with regenerative cells is a promising therapeutic approach and remains a great challenge.