Induced mesenchymal stem cells generated from periodontal ligament fibroblast for regenerative therapy

Bone fractures and bone loss represent significant global health challenges, with their incidence rising due to an aging population. Despite autologous bone grafts remain the gold standard for treatment, challenges such as limited bone availability, immune reactions, and the risk of infectious disease transmission have driven the search for alternative cell-based therapies for bone regeneration. Stem cells derived from oral tissues and umbilical cord mesenchymal stem cells (MSCs) have shown potential in both preclinical and clinical studies for bone tissue regeneration. However, their limited differentiation capacity and wound healing abilities necessitate the exploration of alternative cell sources. In this study, we generated induced pluripotent stem cells (iPSCs) using a safe, nonviral and mRNA-based approach from human periodontal ligament fibroblasts (PDLF), an easily accessible cell source. These iPSCs were subsequently differentiated into MSCs, referred to as induced MSCs (iMSCs). The resulting iMSCs were homogeneous, highly proliferative, and possessed anti-inflammatory properties, suggesting their potential as a superior alternative to traditional MSCs for regenerative therapy. These iMSCs demonstrated trilineage differentiation potential, giving rise to osteocytes, chondrocytes, and adipocytes. The iMSC-derived osteocytes (iOSTs) were homogeneous, patient-specific and showed excellent attachment and growth on commercial collagen-based membranes, highlighting their suitability for bone tissue regeneration applications. Given their promising characteristics compared to traditional MSCs, PDLF-derived iMSCs are strong candidates for future clinical studies in bone regeneration and other regenerative dental therapies.

Functional Outcome Analysis of Autologous Stromal Vascular Fraction (SVF) (Sahaj Therapy®) Using Direct Sonication in Osteonecrosis of the Femoral Head (ONFH): A 6-Year Follow-Up Study

Introduction

We investigated the safety, efficacy, functional, and clinical outcomes of intra-osseous implantation of mechanically isolated, autologous stromal vascular fraction (SVF), an Australian patented direct ultrasonication technology (Sahaj Therapy®) in osteonecrosis of the femoral head (ONFH).

Materials and Methods

A total of 32 cases of ONFH were enrolled in the study after confirming with an MRI of the affected hip. All cases were treated with an intra-osseous autologous SVF implantation [4-5 cc with the cellular dosage of 8.0 × 107 cells with a viability of > 85% SVF cells] on the same surgical sitting. All the cases were followed up clinically, functionally, and radiologically at regular intervals. A comparison of mean HOOS scores at different follow-ups was done using Paired 't'-test. A P value of < 0.05 was considered significant.

Results

In our study, male preponderance was seen (53.1%). According to the modified Ficat and Arlet classification, the most common grade of ONFH was grade 2 [right: 25 hips and left: 25 hips]. There was a statistically significant improvement in the mean HOOS score of the right hip (n = 10) and left hip (n = 9) from preoperative time till 72 months (P < 0.05). The follow-up MRI of the affected hips shows improved osteogenesis without any further worsening of the contour of the femoral head. No adverse effects were seen in any of the study participants.

Conclusion

For individuals with ONFH, treated with intra-osseous autologous SVF implantation in the same surgical procedure is an innovative and promising treatment modality. Even after 6 years of follow-up, the study participants with ONFH have shown good clinical and functional outcomes with autologous SVF.

Chondrocyte Hypertrophy in Osteoarthritis: Mechanistic Studies and Models for the Identification of New Therapeutic Strategies

Articular cartilage shows limited self-healing ability owing to its low cellularity and avascularity. Untreated cartilage defects display an increased propensity to degenerate, leading to osteoarthritis (OA). During OA progression, articular chondrocytes are subjected to significant alterations in gene expression and phenotype, including a shift towards a hypertrophic-like state (with the expression of collagen type X, matrix metalloproteinases-13, and alkaline phosphatase) analogous to what eventuates during endochondral ossification. Present OA management strategies focus, however, exclusively on cartilage inflammation and degradation. A better understanding of the hypertrophic chondrocyte phenotype in OA might give new insights into its pathogenesis, suggesting potential disease-modifying therapeutic approaches. Recent developments in the field of cellular/molecular biology and tissue engineering proceeded in the direction of contrasting the onset of this hypertrophic phenotype, but knowledge gaps in the cause-effect of these processes are still present. In this review we will highlight the possible advantages and drawbacks of using this approach as a therapeutic strategy while focusing on the experimental models necessary for a better understanding of the phenomenon. Specifically, we will discuss in brief the cellular signaling pathways associated with the onset of a hypertrophic phenotype in chondrocytes during the progression of OA and will analyze in depth the advantages and disadvantages of various models that have been used to mimic it. Afterwards, we will present the strategies developed and proposed to impede chondrocyte hypertrophy and cartilage matrix mineralization/calcification. Finally, we will examine the future perspectives of OA therapeutic strategies.