Evaluation of osteochondral-like tissues using human freeze-dried cancellous bone and chondrocyte sheets to treat osteochondral defects in rabbits

Translational application of human keratinocyte-fibroblast cell sheets for accelerated wound healing in a clinically relevant type 2 diabetic rat model

BACKGROUND AIMS

Despite advancements in wound care, wound healing remains a challenge, especially in individuals with type 2 diabetes. Cell sheet technology has emerged as an efficient and promising therapy for tissue regeneration and wound repair. Among these, bilayered human keratinocyte-fibroblast cell sheets constructed using temperature-responsive culture surfaces have been shown to mimic a normal tissue-like structure and secrete essential cytokines and growth factors that regulate the wound healing process.

METHODS

This study aimed to evaluate the safety and therapeutic potential of human skin cell sheets to treat full-thickness skin defects in a rat model of type 2 diabetes.

RESULTS

Our findings demonstrate that diabetic wounds transplanted with bilayered cell sheets resulted in accelerated re-epithelialization, increased angiogenesis, enhanced macrophage polarization and regeneration of tissue that closely resembled healthy skin. In contrast, the control group that did not receive cell sheet transplantation presented characteristic symptoms of impaired and delayed wound healing associated with type 2 diabetes.

CONCLUSIONS

The secretory cytokines and the upregulation of Nrf2 expression in response to cell sheet transplantation are believed to have played a key role in the improved wound healing observed in diabetic rats. Our study suggests that human keratinocyte-fibroblast cell sheets hold great potential as a therapeutic alternative for diabetic ulcers.

Decreased FoxO1 expression contributes to facet joint osteoarthritis pathogenesis by impairing chondrocyte migration and extracellular matrix synthesis

Facet joint osteoarthritis (FJOA), a condition commonly observed in individuals of middle to old age, has been relatively under-researched compared to other subtypes of osteoarthritis (OA). This study investigated the role of transcription factor FoxO1 in FJOA using a Col2a1-creERT knock-in mouse model. It was found that FoxO1 deletion led to severe osteoarthritic changes, indicating that FoxO1 played a critical role in cartilage homeostasis. Transcriptome sequencing was performed on degenerated cartilage from FoxO1-deleted mice. This process identified differentially expressed genes (DEGs), offering insights into the molecular mechanisms underlying FJOA. Bioinformatics analysis, including Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Set Enrichment Analysis (GSEA) and protein-protein interaction (PPI) network analysis, identified Itgb3, Itga1, Itga6, Itga7, Itga8, Itga10, Col1a1, and Il6, as potential key contributors to FJOA after FoxO1 deletion. Importantly, overexpression of Itgb3 and inhibition of Il6 counteracted FoxO1 knockdown-induced impairments in chondrocyte migration and extracellular matrix synthesis, respectively. This study discovered FoxO1 as a key regulator of the pathogenesis of FJOA, helped unravel the complex molecular mechanisms underlying FJOA, and contributed to the development of promising therapeutic avenues toward FJOA.

Recent Biomimetic Approaches for Articular Cartilage Tissue Engineering and Their Clinical Applications: Narrative Review of the Literature

Since articular cartilage is lacking blood vessels and nerves, its capacity to heal is extremely limited. This means that ruptured cartilage affects the joint as a whole. A health issue known as osteoarthritis can develop as a result of injury and deterioration. Osteoarthritis development can be speeded up by the widespread deterioration of articular cartilage, which ranks third on the list of musculoskeletal disorders requiring rehabilitation, behind only low back pain and broken bones. The current treatments for cartilage repair are ineffective and rarely restore full function or tissue normalcy. A promising new technology in tissue engineering may help create functional cartilage tissue substitutes. Ensuring that the cell source is loaded with bioactive molecules that promote cellular differentiation and/or maturation is the general approach. This review summarizes recent advances in cartilage tissue engineering, and recent clinical trials have been conducted to provide a comprehensive overview of the most recent research developments and clinical applications in the framework of degenerated articular cartilage and osteoarthritis.

Current Advances in the Regeneration of Degenerated Articular Cartilage: A Literature Review on Tissue Engineering and Its Recent Clinical Translation

Functional ability is the basis of healthy aging. Articular cartilage degeneration is amongst the most prevalent degenerative conditions that cause adverse impacts on the quality of life; moreover, it represents a key predisposing factor to osteoarthritis (OA). Both the poor capacity of articular cartilage for self-repair and the unsatisfactory outcomes of available clinical interventions make innovative tissue engineering a promising therapeutic strategy for articular cartilage repair. Significant progress was made in this field; however, a marked heterogeneity in the applied biomaterials, biofabrication, and assessments is nowadays evident by the huge number of research studies published to date. Accordingly, this literature review assimilates the most recent advances in cell-based and cell-free tissue engineering of articular cartilage and also focuses on the assessments performed via various in vitro studies, ex vivo models, preclinical in vivo animal models, and clinical studies in order to provide a broad overview of the latest findings and clinical translation in the context of degenerated articular cartilage and OA.

Integrins, cadherins and channels in cartilage mechanotransduction: perspectives for future regeneration strategies

Articular cartilage consists of hyaline cartilage, is a major constituent of the human musculoskeletal system and has critical functions in frictionless joint movement and articular homoeostasis. Osteoarthritis (OA) is an inflammatory disease of articular cartilage, which promotes joint degeneration. Although it affects millions of people, there are no satisfying therapies that address this disease at the molecular level. Therefore, tissue regeneration approaches aim at modifying chondrocyte biology to mitigate the consequences of OA. This requires appropriate biochemical and biophysical stimulation of cells. Regarding the latter, mechanotransduction of chondrocytes and their precursor cells has become increasingly important over the last few decades. Mechanotransduction is the transformation of external biophysical stimuli into intracellular biochemical signals, involving sensor molecules at the cell surface and intracellular signalling molecules, so-called mechano-sensors and -transducers. These signalling events determine cell behaviour. Mechanotransducing ion channels and gap junctions additionally govern chondrocyte physiology. It is of great scientific and medical interest to induce a specific cell behaviour by controlling these mechanotransduction pathways and to translate this knowledge into regenerative clinical therapies. This review therefore focuses on the mechanotransduction properties of integrins, cadherins and ion channels in cartilaginous tissues to provide perspectives for cartilage regeneration.