Peripheral Blood-Derived Stem Cells for the Treatment of Cartilage Injuries: A Systematic Review

Latest Advances in Chondrocyte-Based Cartilage Repair

Chondrocyte-based cell therapy has been used for more than 30 years and is still considered to be a promising method of cartilage repair despite some limitations. This review introduces the latest developments of four generations of autologous chondrocyte implantation and current autologous chondrocyte products. The regeneration of cartilage from adult chondrocytes is limited by culture-induced dedifferentiation and patient age. Cartibeads is an innovative three-step method to produce high-quality hyaline cartilage microtissues, and it is developed from adult dedifferentiated chondrocytes with a high number of cell passages. In addition, allogeneic chondrocyte therapies using the Quantum hollow-fiber bioreactor and several signaling pathways involved in chondrocyte-based cartilage repair are mentioned, such as WNT signaling, the BMP-2/WISP1 pathway, and the FGF19 pathway.

Identifying transcriptomic profiles of iron-quercetin complex treated peripheral blood mononuclear cells from healthy volunteers and diabetic patients

Peripheral blood is an alternative source of stem/progenitor cells for regenerative medicine owing to its ease of retrieval and blood bank storage. Previous in vitro studies indicated that the conditioned medium derived from peripheral blood mononuclear cells (PBMCs) treated with the iron-quercetin complex (IronQ) contains potent angiogenesis and wound-healing properties. This study aims to unveil the intricate regulatory mechanisms governing the effects of IronQ on the transcriptome profiles of human PBMCs from healthy volunteers and those with diabetes mellitus (DM) using RNA sequencing analysis. Our findings revealed 3741 and 2204 differentially expressed genes (DEGs) when treating healthy and DM PBMCs with IronQ, respectively. Functional enrichment analyses underscored the biological processes shared by the DEGs in both conditions, including inflammatory responses, cell migration, cellular stress responses, and angiogenesis. A comprehensive exploration of these molecular alterations exposed a network of 20 hub genes essential in response to stimuli, cell migration, immune processes, and the mitogen-activated protein kinase (MAPK) pathway. The activation of these pathways enabled PBMCs to potentiate angiogenesis and tissue repair. Corroborating this, quantitative real-time polymerase chain reaction (qRT-PCR) and cell phenotyping confirmed the upregulation of candidate genes associated with anti-inflammatory, pro-angiogenesis, and tissue repair processes in IronQ-treated PBMCs. In summary, combining IronQ and PBMCs brings about substantial shifts in gene expression profiles and activates pathways that are crucial for tissue repair and immune response, which is promising for the enhancement of the therapeutic potential of PBMCs, especially in diabetic wound healing.

Preclinical Animal Study and Pilot Clinical Trial of Using Enriched Peripheral Blood-Derived Mononuclear Cells for Intervertebral Disc Degeneration

Low back pain (LBP) is a leading cause of long-term disability globally. Intervertebral disk degeneration (IVDD) is mainly responsible for discogenic pain in LBP-affected young patients. There is no effective therapy to reverse disease severity and IVDD progression. This study investigates the effect of human peripheral blood-derived mononuclear cells (PBMCs) on pain relief and life quality improvement in IVDD patients. The enriched monocytes of the PBMCs could differentiate into CD14 and CD206 double-positive M2 macrophages in vitro. Preclinical evidence in rats showed that the transplanted PBMCs exhibited anti-inflammatory and moderate tissue-repair effects on controlling IVDD progress in the rat model. The PBMCs significantly steered the aggrecan and type II collagen expressions and attenuated the pro-inflammatory cytokines in the affected disk. Based on the animal results, 36 patients with chronic low back pain (CLBP) were included in clinical trials. The control group was conservative care only, and the experimental group was platelet-rich plasma (PRP) and PBMCs intradiscal injections. We first confirmed the single lumbar disk causing the discogenic pain by provocative discography or magnetic resonance imaging (MRI). Discogenic LBP participants received one intradiscal injection of autologous PBMCs and followed for 6 months. Our clinical trial showed that patients' LBP and disability were significantly ameliorated after the PBMCs transplantation rather than PRP. These preclinical and pilot clinical studies indicate that intradiscal injection of the enriched PBMCs might be a feasible and potential cell therapy to control pain and disability in IVDD patients.

Enriched Peripheral Blood-Derived Mononuclear Cells for Treating Knee Osteoarthritis

Osteoarthritis (OA) is a common chronic skeletal disease in the elderly. There is no effective therapy to reverse disease severity and knee OA (KOA) progression, particularly at the late stage. This study aims to examine the effect of peripheral blood-derived mononuclear cells (PBMNCs) on pain and motor function rescue in patients with Kellgren-Lawrence (KL) grade II to IV KOA. Participants received one intra-articular (IA) injection of autologous PBMNCs. The mononuclear cells were isolated from peripheral blood, enriched by a specialized medium (MoFi medium), and separated by Ficoll-Paque solution. The isolated and enriched PBMNCs could differentiate into M1 and M2 macrophages in vitro. The in vivo anti-inflammatory effect of the PBMNCs was similar to that of bone marrow mesenchymal stem cells, evaluated by complete Freund's adjuvant-induced arthritis in rodents. A single-arm and open-label pilot study showed that patients' knee pain and motor dysfunction were significantly attenuated after the cell transplantation, assessed by visual analogue scale (VAS) and Knee injury and Osteoarthritis Outcome Score (KOOS) at 6 and 12 months post-treatment. Notably, the therapeutic effect of the PBMNCs treatment can be stably maintained for 24 months, as revealed by the KOOS scores. These preclinical and pilot clinical data suggest that IA injection of MoFi-PBMNCs might serve as a novel medical technology to control the pain and the progress of KOA.