Chitosan-cartilage extracellular matrix hybrid scaffold induces chondrogenic differentiation to adipose-derived stem cells

Bioprinted biomimetic hydrogel matrices guiding stem cell aggregates for enhanced chondrogenesis and cartilage regeneration

Articular cartilage tissue has limited self-repair capabilities, with damage frequently progressing to irreversible degeneration. Engineered tissues constructed through bioprinting and embedded with stem cell aggregates offer promising therapeutic alternatives. Aggregates of bone marrow mesenchymal stromal cells (BMSCs) demonstrate enhanced and more rapid chondrogenic differentiation than isolated cells, thus facilitating cartilage repair. However, it remains a key challenge to precisely control biochemical microenvironments to regulate cellular adhesion and cohesion within bioprinted matrices simultaneously. Herein, this work reports a bioprintable hydrogel matrix with high cellular adhesion and aggregation properties for cartilage repair. The hydrogel comprises an enhanced cell-adhesive gelatin methacrylate and a cell-cohesive chitosan methacrylate (CHMA), both of which are subjected to photo-initiated crosslinking. By precisely adjusting the CHMA content, the mechanical stability and biochemical cues of the hydrogels are finely tuned to promote cellular aggregation, chondrogenic differentiation and cartilage repair implantation. Multi-layer constructs encapsulated with BMSCs, with high cell viability reaching 91.1%, are bioprinted and photo-crosslinked to support chondrogenic differentiation for 21 days. BMSCs rapidly form aggregates and display efficient chondrogenic differentiation both on the hydrogels and within bioprinted constructs, as evidenced by the upregulated expression of Sox9, Aggrecan and Collagen 2a1 genes, along with high protein levels. Transplantation of these BMSC-laden bioprinted hydrogels into cartilaginous defects demonstrates effective hyaline cartilage repair. Overall, this cell-responsive hydrogel scaffold holds immense promise for applications in cartilage tissue engineering.

Recent Applications of Chitosan and Its Derivatives in Antibacterial, Anticancer, Wound Healing, and Tissue Engineering Fields

Chitosan, a versatile biopolymer derived from chitin, has garnered significant attention in various biomedical applications due to its unique properties, such as biocompatibility, biodegradability, and mucoadhesiveness. This review provides an overview of the diverse applications of chitosan and its derivatives in the antibacterial, anticancer, wound healing, and tissue engineering fields. In antibacterial applications, chitosan exhibits potent antimicrobial properties by disrupting microbial membranes and DNA, making it a promising natural preservative and agent against bacterial infections. Its role in cancer therapy involves the development of chitosan-based nanocarriers for targeted drug delivery, enhancing therapeutic efficacy while minimising side effects. Chitosan also plays a crucial role in wound healing by promoting cell proliferation, angiogenesis, and regulating inflammatory responses. Additionally, chitosan serves as a multifunctional scaffold in tissue engineering, facilitating the regeneration of diverse tissues such as cartilage, bone, and neural tissue by promoting cell adhesion and proliferation. The extensive range of applications for chitosan in pharmaceutical and biomedical sciences is not only highlighted by the comprehensive scope of this review, but it also establishes it as a fundamental component for forthcoming research in biomedicine.

Advancements in culture technology of adipose-derived stromal/stem cells: implications for diabetes and its complications

Stem cell-based therapies exhibit considerable promise in the treatment of diabetes and its complications. Extensive research has been dedicated to elucidate the characteristics and potential applications of adipose-derived stromal/stem cells (ASCs). Three-dimensional (3D) culture, characterized by rapid advancements, holds promise for efficacious treatment of diabetes and its complications. Notably, 3D cultured ASCs manifest enhanced cellular properties and functions compared to traditional monolayer-culture. In this review, the factors influencing the biological functions of ASCs during culture are summarized. Additionally, the effects of 3D cultured techniques on cellular properties compared to two-dimensional culture is described. Furthermore, the therapeutic potential of 3D cultured ASCs in diabetes and its complications are discussed to provide insights for future research.

Injectable hydrogel for sustained delivery of progranulin derivative Atsttrin in treating diabetic fracture healing

Hydrogels with long-term storage stability, controllable sustained-release properties, and biocompatibility have been garnering attention as carriers for drug/growth factor delivery in tissue engineering applications. Chitosan (CS)/Graphene Oxide (GO)/Hydroxyethyl cellulose (HEC)/β-glycerol phosphate (β-GP) hydrogel is capable of forming a 3D gel network at physiological temperature (37 °C), rendering it an excellent candidate for use as an injectable biomaterial. This work focused on an injectable thermo-responsive CS/GO/HEC/β-GP hydrogel, which was designed to deliver Atsttrin, an engineered derivative of a known chondrogenic and anti-inflammatory growth factor-like molecule progranulin. The combination of the CS/GO/HEC/β-GP hydrogel and Atsttrin provides a unique biochemical and biomechanical environment to enhance fracture healing. CS/GO/HEC/β-GP hydrogels with increased amounts of GO exhibited rapid sol-gel transition, higher viscosity, and sustained release of Atsttrin. In addition, these hydrogels exhibited a porous interconnected structure. The combination of Atsttrin and hydrogel successfully promoted chondrogenesis and osteogenesis of bone marrow mesenchymal stem cells (bmMSCs) in vitro. Furthermore, the work also presented in vivo evidence that injection of Atsttrin-loaded CS/GO/HEC/β-GP hydrogel stimulated diabetic fracture healing by simultaneously inhibiting inflammatory and stimulating cartilage regeneration and endochondral bone formation signaling pathways. Collectively, the developed injectable thermo-responsive CS/GO/HEC/βG-P hydrogel yielded to be minimally invasive, as well as capable of prolonged and sustained delivery of Atsttrin, for therapeutic application in impaired fracture healing, particularly diabetic fracture healing.

Synergistic effects of 3D chitosan-based hybrid scaffolds and mesenchymal stem cells in orthopaedic tissue engineering

Restoration of damaged bone and cartilage tissue with biomaterial scaffolds is an area of interest in orthopaedics. Chitosan is among the low-cost biomaterials used as scaffolds with considerable biocompability to almost every human tissue. Considerable osteoconductivity, porosity, and appropriate pore size distribution have made chitosan an appropriate scaffold for loading of stem cells and a good homing place for differentiation of stem cells to bone tissue. Moreover, the similarity of chitosan to glycosaminoglycans and its potential to be used as soft gels, which could be lasting more than 1 week in mobile chondral defects, has made chitosan a polymer of interest in repairing bone and cartilage defects. Different types of scaffolds using chitosan in combination with mesenchymal stem cells (MSCs) are discussed. MSCs are widely used in regenerative medicine because of their regenerative ability, and recent line evidence reviewed demonstrated that the combination of MSCs with a combination of chitosan with different materials, including collagen type 1, hyaluronic acid, Poly(L-lacticacid)/gelatin/β-tricalcium phosphate, gamma-poly[glutamic acid] polyelectrolyte/titanium alloy, modified Poly(L-Lactide-co-Epsilon-Caprolactone), calcium phosphate, β-glycerophosphate hydrogel/calcium phosphate cement (CPC), and CPC-Chitosan-RGD, can increase the efficacy of using MSCs, and chitosan-based stem cell delivery can be a promising method in restoration of damaged bone and cartilage tissue.

In Vitro Chondrogenic Differentiation of Human Adipose-Derived Stem Cells by Diacerein

Background

Tissue engineering is the application system that tries to restore damaged tissues by different approaches, such as cellular therapy, application of cell differential factors, and various materials. One of the important goals in tissue engineering is to guide stem cells directly to the desired tissue, and researchers tried to utilize different molecules as effective factors to improve this technique.

Objectives

This study aims to demonstrate the effects of diacerein, a slow-acting drug for the treatment of osteoarthritis, on mesenchymal stem cell proliferation and evaluate its potential in the chondrogenesis process.

Methods

Stem cells were isolated from adipose tissue, characterized by flow cytometry, and cells were treated with 10-5M diacerein for three weeks. Chondrogenic gene expression of SOX9, COL2A1, ACAN, and TGFB1 were analyzed by qRT-PCR and immunocytochemistry techniques.

Results

Our results showed that diacerein increased the expression of the following genes involved in chondrogenesis: SOX9 (2.9-fold, P < 0.00), COL2A1 (2.2-fold, P < 0.00), ACAN (2.7-fold, P < 0.00), and TGFB1 (2.6-fold, P < 0.00). Immunocytochemistry results also showed increased production of collagen type II as the main protein marker for chondrocytes.

Conclusions

We observed that diacerein alone could initiate and enhance chondrogenesis, and it can be used as a differentiation factor for stem cells to chondrocyte besides its ability to inhibit IL-1β. Knowing the actual function of diacerein, it could be a good candidate for the treatment of osteoarthritis.

Systematic review on spheroids from adipose‐derived stem cells: Spontaneous or artefact state?

Three-dimensional (3D) cell cultures represent the spontaneous state of stem cells with specific gene and protein molecular expression that are more alike the in vivo condition. In vitro two-dimensional (2D) cell adhesion cultures are still commonly employed for various cellular studies such as movement, proliferation and differentiation phenomena; this procedure is standardized and amply used in laboratories, however their representing the original tissue has recently been subject to questioning. Cell cultures in 2D require a support/substrate (flasks, multiwells, etc.) and use of fetal bovine serum as an adjuvant that stimulates adhesion that most likely leads to cellular aging. A 3D environment stimulates cells to grow in suspended aggregates that are defined as "spheroids." In particular, adipose stem cells (ASCs) are traditionally observed in adhesion conditions, but a recent and vast literature offers many strategies that obtain 3D cell spheroids. These cells seem to possess a greater ability in maintaining their stemness and differentiate towards all mesenchymal lineages, as demonstrated in in vitro and in vivo studies compared to adhesion cultures. To date, standardized procedures that form ASC spheroids have not yet been established. This systematic review carries out an in-depth analysis of the 76 articles produced over the past 10 years and discusses the similarities and differences in materials, techniques, and purposes to standardize the methods aimed at obtaining ASC spheroids as already described for 2D cultures.

Alendronate crosslinked chitosan/polycaprolactone scaffold for bone defects repairing

Here, we evaluated osteogenic differentiation in vitro and new bone formation in vivo using an alendronate-loaded chitosan/polycaprolactone scaffold (CS/PCL) in rats with a critical-sized calvarial defect. Through the action of genipin, which has a crosslinking function, alendronate (AL) was anchored throughout the CS/PCL composite scaffold (CS/PCL@AL) to form an AL sustained release system. We demonstrated that CS/PCL@AL scaffolds significantly enhanced the osteogenic differentiation of ectomesenchymal stem cells (EMSCs) in vitro. Additionally, we explored the possible molecular mechanism of CS/PCL@AL scaffolds in the osteogenic differentiation of EMSCs. This composite scaffold exerted two positive effects on EMSC osteogenic differentiation: 1) the CS/PCL@AL scaffold enhanced EMSC osteogenic differentiation by upregulating bone morphogenetic protein 2, interleukin 10 and laminin expression; and 2) the CS/PCL@AL scaffold promoted the osteogenic differentiation of EMSCs by activating the yes-associated protein (YAP) signaling pathway. YAP and its downstream target transglutaminase are crucial mediators in the osteogenic differentiation of EMSCs. Finally, micro-computed tomography analyses and histology results suggested that the CS/PCL@AL scaffold exhibited a superior capacity to accelerate new and mature bone formation in skull bone defects in Sprague-Dawley rats. This simple and low-cost technology may represent a promising strategy to construct an efficient delivery system to repair bone defects.

The effect of cartilage decellularized extracellular matrix-chitosan compound on treating knee osteoarthritis in rats

Knee osteoarthritis (KOA) refers to a common disease in orthopaedics, whereas effective treatments have been rarely developed. As indicated from existing studies, chondrocyte death, extracellular matrix degradation and subchondral bone injury are recognized as the pathological basis of KOA. The present study aimed to determine the therapeutic effect of decellularized extracellular matrix-chitosan (dECM-CS) compound on KOA. In this study, rat knee cartilage was decellularized, and a satisfactory decellularized extracellular matrix was developed. As suggested from the in vitro experiments, the rat chondrocytes co-cultured with allogeneic dECM grew effectively. According to the results of the alamar blue detection, dECM did not adversely affect the viability of rat chondrocytes, and dECM could up-regulate the genes related to the cartilage synthesis and metabolism. As reported from the animal experiments, dECM-CS compound could protect cartilage, alleviate knee joint pain in rats, significantly delay the progress of KOA in rats, and achieve high drug safety. In brief, dECM-CS compound shows a good therapeutic effect on KOA.

Mechanotransducive Biomimetic Systems for Chondrogenic Differentiation In Vitro

Osteoarthritis (OA) is a long-term chronic joint disease characterized by the deterioration of bones and cartilage, which results in rubbing of bones which causes joint stiffness, pain, and restriction of movement. Tissue engineering strategies for repairing damaged and diseased cartilage tissue have been widely studied with various types of stem cells, chondrocytes, and extracellular matrices being on the lead of new discoveries. The application of natural or synthetic compound-based scaffolds for the improvement of chondrogenic differentiation efficiency and cartilage tissue engineering is of great interest in regenerative medicine. However, the properties of such constructs under conditions of mechanical load, which is one of the most important factors for the successful cartilage regeneration and functioning in vivo is poorly understood. In this review, we have primarily focused on natural compounds, particularly extracellular matrix macromolecule-based scaffolds and their combinations for the chondrogenic differentiation of stem cells and chondrocytes. We also discuss different mechanical forces and compression models that are used for In Vitro studies to improve chondrogenic differentiation. Summary of provided mechanical stimulation models In Vitro reviews the current state of the cartilage tissue regeneration technologies and to the potential for more efficient application of cell- and scaffold-based technologies for osteoarthritis or other cartilage disorders.

Chondro-inductive hyaluronic acid/chitosan coacervate-based scaffolds for cartilage tissue engineering

Injuries related to articular cartilage are among the most challenging musculoskeletal problems because of poor repair capacity of this tissue. The lack of efficient treatments for chondral defects has stimulated research on cartilage tissue engineering applications combining porous biocompatible scaffolds with stem cells in the presence of external stimuli. This work presents the role of rat bone marrow mesenchymal stem cell (BMSC) encapsulated-novel three-dimensional (3D) coacervate scaffolds prepared through complex coacervation between different chitosan salts (CHI) and sodium hyaluronate (HA). The 3D architecture of BMSC encapsulated scaffolds (HA/CHI) was shown by scanning electron microscopy (SEM) to have an interconnected structure to allow cell-cell and cell-matrix interactions. Chondrogenic induction of encapsulated BMSCs within HA/CHI coacervates demonstrated remarkable cellular viability in addition to the elevated expression levels of chondrogenic markers such as sex determining region Y-box 9 protein (SOX9), aggrecan (ACAN), cartilage oligomeric matrix protein (COMP) and collagen type II (COL2A1) by immunofluorescence staining, qPCR and ELISA test. Collectively, HA/CHI coacervates are promising candidates for future use of these scaffolds in cartilage tissue engineering applications.

Characterization of Chitosan-Based Scaffolds Seeded with Sheep Nasal Chondrocytes for Cartilage Tissue Engineering

The treatment of cartilage defect remains a challenging issue in clinical practice. Chitosan-based materials have been recognized as a suitable microenvironment for chondrocyte adhesion, proliferation and differentiation forming articular cartilage. The use of nasal chondrocytes to culture articular cartilage on an appropriate scaffold emerged as a promising novel strategy for cartilage regeneration. Beside excellent properties, chitosan lacks in biological activity, such as RGD-sequences. In this work, we have prepared pure and protein-modified chitosan scaffolds of different deacetylation degree and molecular weight as platforms for the culture of sheep nasal chondrocytes. Fibronectin (FN) was chosen as an adhesive protein for the improvement of chitosan bioactivity. Prepared scaffolds were characterised in terms of microstructure, physical and biodegradation properties, while FN interactions with different chitosans were investigated through adsorption-desorption studies. The results indicated faster enzymatic degradation of chitosan scaffolds with lower deacetylation degree, while better FN interactions with material were achieved on chitosan with higher number of amine groups. Histological and immunohistochemical analysis of in vitro engineered cartilage grafts showed presence of hyaline cartilage produced by nasal chondrocytes.