Application of Bio-Active Elastin-like Polypeptide on Regulation of Human Mesenchymal Stem Cell Behavior

Regenerative medicine using stem cells offers promising strategies for treating a variety of degenerative diseases. Regulation of stem cell behavior and rejuvenate senescence are required for stem cells to be clinically effective. The extracellular matrix (ECM) components have a significant impact on the stem cell’s function and fate mimicking the local environment to maintain cells or generate a distinct phenotype. Here, human elastin-like polypeptide-based ECM-mimic biopolymer was designed by incorporating various cell-adhesion ligands, such as RGD and YIGSR. The significant effects of bioactive fusion ELPs named R-ELP, Y-ELP, and RY-ELP were analyzed for human bone-marrow-derived stem cell adhesion, proliferation, maintenance of stemness properties, and differentiation. Multivalent presentation of variable cell-adhesive ligands on RY-ELP polymers indeed promote efficient cell attachment and proliferation of human fibroblast cells dose-dependently. Similarly, surface modified with RY-ELP promoted strong mesenchymal stem cell (MSCs) attachment with greater focal adhesion (FA) complex formation at 6 h post-incubation. The rate of cell proliferation, migration, population doubling time, and collagen I deposition were significantly enhanced in the presence of RY-ELP compared with other fusion ELPs. Together, the expression of multipotent markers and differentiation capacity of MSCs remained unaffected, clearly demonstrating that stemness properties of MSCs were well preserved when cultured on a RY-ELP-modified surface. Hence, bioactive RY-ELP offers an anchorage support system and effectively induces stimulatory response to support stem cell proliferation.

Intra-Articular Bone Marrow Aspirate Concentrate Injection in Patients with Knee Osteoarthritis

We aimed to evaluate the 5-year follow-up outcomes of an intra-articular bone marrow aspirate concentrate (BMAC) injection in patients with knee osteoarthritis. This is the first study to report the outcomes following BMAC injections over a 5-year follow-up period. Seventy knees of 37 patients, including 33 bilateral knees, were investigated. The primary outcome was the visual analogue scale (VAS) score for pain in the knee joint, and the secondary outcomes were the International Knee Documentation Committee score, the 36-Item Short Form Health Survey score, the Knee injury Osteoarthritis Outcome Score, Lysholm Knee Questionnaire/Tegner activity scale, BMAC injection-induced complications, and 5-year treatment success rate. The 5-year post-injection VAS scores (4.7 ± 0.5) were significantly lower than the preoperative scores (8.3 ± 1.2) (p = 0.01). Improvement in VAS scores was significantly greater in patients with Kellgren–Lawrence (K-L) Grade I or II than those in those with K-L Grade III or IV. Improvement in other clinical parameters and success rates were significantly low and the rates of secondary operation and failure were significantly higher in patients with K-L Grades III or IV. Intra-articular BMAC injections could be useful for managing patients with K-L Grades I or II osteoarthritis.