Restoration of cartilage defects using a superparamagnetic iron oxide-labeled adipose-derived mesenchymal stem cell and TGF-β3-loaded bilayer PLGA construct

A Contemporary Review of Trachea, Nose, and Ear Cartilage Bioengineering and Additive Manufacturing

The complex structure, chemical composition, and biomechanical properties of craniofacial cartilaginous structures make them challenging to reconstruct. Autologous grafts have limited tissue availability and can cause significant donor-site morbidity, homologous grafts often require immunosuppression, and alloplastic grafts may have high rates of infection or displacement. Furthermore, all these grafting techniques require a high level of surgical skill to ensure that the reconstruction matches the original structure. Current research indicates that additive manufacturing shows promise in overcoming these limitations. Autologous stem cells have been developed into cartilage when exposed to the appropriate growth factors and culture conditions, such as mechanical stress and oxygen deprivation. Additive manufacturing allows for increased precision when engineering scaffolds for stem cell cultures. Fine control over the porosity and structure of a material ensures adequate cell adhesion and fit between the graft and the defect. Several recent tissue engineering studies have focused on the trachea, nose, and ear, as these structures are often damaged by congenital conditions, trauma, and malignancy. This article reviews the limitations of current reconstructive techniques and the new developments in additive manufacturing for tracheal, nasal, and auricular cartilages.

miR-92a-3p-inspired shRNA exhibits pro-chondrogenic and chondrocyte protective effects in osteoarthritis treatment through targeting SMAD6/7

INTRODUCTION

Osteoarthritis (OA) compromises patients' quality of life and requires further study. Although miR-92a-3p was reported to possess chondroprotective effects, the underlying mechanism requires further clarification. The objectives of this study were to elucidate the mechanism by which miR-92a-3p alleviates OA and to examine the efficacy of shRNA-92a-3p, which was designed based on mature miR-92a-3p.

MATERIALS AND METHODS

TargetScan and luciferase reporter assay were used to predict the target of miR-92a-3p. Adipose-derived stem cells (ADSCs) were transfected with miR-92a-3p/miR-NC mimic for the analysis of chondrogenic biomarkers and SMAD proteins. ADSCs and osteoarthritic chondrocytes were transduced with shRNA-92a-3p for the analysis of chondrogenic biomarkers and SMAD proteins. OA was surgically induced in C57BL/6JJcl mice, and ADSCs with/without shRNA-92a-3p transduction were intra-articularly injected for the assessment of cartilage damage.

RESULTS

SMAD6 and SMAD7 were predicted as direct targets of miR-92a-3p by TargetScan and luciferase reporter assay. Transfection of the miR-92a-3p mimic resulted in a decrease in SMAD6 and SMAD7 levels and an increase in phospho-SMAD2/3, phospho-SMAD1/5/9, SOX9, collagen type II, and aggrecan levels in ADSCs. Furthermore, shRNA-92a-3p decreased SMAD6 and SMAD7 levels, and increased phospho-SMAD2/3, phospho-SMAD1/5/9, SOX9, collagen type II, and aggrecan levels in ADSCs and osteoarthritic chondrocytes. Additionally, ADSC-shRNA-92a-3p-EVs reduced the rate of decrease of SOX9, collagen type II, and aggrecan in osteoarthritic chondrocytes. In mice with surgically induced OA, shRNA-92a-3p-treated ADSCs alleviated cartilage damage more effectively than nontreated ADSCs.

CONCLUSIONS

miR-92a-3p and shRNA-92a-3p exhibit therapeutic effects in treating OA by targeting SMAD6 and SMAD7, thereby enhancing TGF-β signaling.

Cartilage 3D bioprinting for rhinoplasty using adipose-derived stem cells as seed cells: Review and recent advances

Nasal deformities due to various causes affect the aesthetics and use of the nose, in which case rhinoplasty is necessary. However, the lack of cartilage for grafting has been a major problem and tissue engineering seems to be a promising solution. 3D bioprinting has become one of the most advanced tissue engineering methods. To construct ideal cartilage, bio-ink, seed cells, growth factors and other methods to promote chondrogenesis should be considered and weighed carefully. With continuous progress in the field, bio-ink choices are becoming increasingly abundant, from a single hydrogel to a combination of hydrogels with various characteristics, and more 3D bioprinting methods are also emerging. Adipose-derived stem cells (ADSCs) have become one of the most popular seed cells in cartilage 3D bioprinting, owing to their abundance, excellent proliferative potential, minimal morbidity during harvest and lack of ethical considerations limitations. In addition, the co-culture of ADSCs and chondrocytes is commonly used to achieve better chondrogenesis. To promote chondrogenic differentiation of ADSCs and construct ideal highly bionic tissue-engineered cartilage, researchers have used a variety of methods, including adding appropriate growth factors, applying biomechanical stimuli and reducing oxygen tension. According to the process and sequence of cartilage 3D bioprinting, this review summarizes and discusses the selection of hydrogel and seed cells (centered on ADSCs), the design of printing, and methods for inducing the chondrogenesis of ADSCs.

Fabrication of Tissue-Engineered Cartilage Using Decellularized Scaffolds and Chondrocytes

In this paper, we aim to explore the application value of tissue engineering for the construction of artificial cartilage in vitro. Chondrocytes from healthy porcine articular cartilage tissue were seeded on articular cartilage extracellular matrix (ACECM) scaffolds and cultivated. Type II collagen immunofluorescent staining was used to assess secretion from the extracellular matrix. Chondrocytes, which were mainly polygonal and cobblestone-shaped, were inoculated on ACECM-oriented scaffolding for 7 days, and the neo-tissue showed translucent shape and toughness. Using inverted and fluorescence microscopy, we found that chondrocytes on the scaffolds performed well in terms of adhesion and growth, and they secreted collagen type II. Moreover, the porcine ACECM scaffolds had good biocompatibility. The inflammatory cell detection, cellular immune response assay and humoral immune response assay showed porcine ACECM scaffolds were used for xenotransplantation without significant immune inflammatory response. All these findings reveal that ACECM-oriented scaffold is an ideal natural biomaterial for cartilage tissue engineering.