RESUMO
【Objective】 To discuss the repair effect of lyophilized platelet lysate (PL) products on articular cartilage injury model of rats. 【Methods】 A total of 25 SD rats were injected with typeⅡcollagenase at the right knuckle articular cavity respectively on day 1, 3 and 5 of experiment, and the modeling conditions were observed 14 days after the last injection of collagenase. The SD rats with successful modeling were randomly divided into three groups, and were injected with lyophilized PL [Group A, 1 mL/(mouse·time)], PL [Group B, 1 mL/(mouse·time)], and normal saline[Group C, 1 mL/(mouse·time)]. The above three substances were injected with corresponding drugs on day 0, 7, 14 and 21 of experiment based on the grouping conditions, and the changes of knee joint diameters of the rats from the three groups were observed and compared. On day 14 and 28, one rat in each group was randomly killed and two knuckle articular cavities of each were taken for tissue sampling, using hematoxylin-eosin staining (HE) and immunohistochemistry. 【Results】 After 14 days of modeling by injection of type Ⅱ collagenase, the proportion of successful modeling in rats was 84% (21/25), with the knee joint diameter (mm) before and after modeling at 12.84±1.14 vs 14.11±1.17(P<0.01). On day 14, 21 and 28, groups A and B were superior to group C in the knee joint diameter and activity improvement (P<0.05), with 13.33±1.16 vs 13.37±1.08 vs 14.21±1.08, 13.10±1.09 vs 13.01±1.04 vs 14.09±1.09 and 12.38±1.08 vs 12.51±1.03 vs 14.01±1.07, respectively. Histological observation showed that group A and B were superior to group C in the production and arrangement of chondrocytes and the positive expression of type Ⅱ collagen, and there was no significant difference between group A and group B. 【Conclusion】 The lyophilized PL has similar therapeutic effect to PL in the treatment and repair of articular cartilage injury, and is worthy of clinical application.
RESUMO
Objective: To summarize the effect of cartilage progenitor cells (CPCs) and microRNA-140 (miR-140) on the repair of osteoarthritic cartilage injury, and analyze their clinical prospects. Methods: The recent researches regarding the CPCs, miR-140, and repair of cartilage in osteoarthritis (OA) disease were extensively reviewed and summarized. Results: CPCs possess the characteristics of self-proliferation, expression of stem cell markers, and multi-lineage differentiation potential, and their chondrogenic ability is superior to other tissues-derived mesenchymal stem cells. CPCs are closely related to the development of OA, but the autonomic activation and chondrogenic ability of CPCs around the osteoarthritic cartilage lesion cannot meet the requirements of complete cartilage repair. miR-140 specifically express in cartilage, and has the potential to activate CPCs by inhibiting key molecules of Notch signaling pathway and enhance its chondrogenic ability, thus promoting the repair of osteoarthritic cartilage injury. Intra-articular delivery of drugs is one of the main methods of OA treatment, although intra-articular injection of miR-140 has a significant inhibitory effect on cartilage degeneration in rats, it also exhibit some limitations such as non-targeted aggregation, low bioavailability, and rapid clearance. So it is a good application prospect to construct a carrier with good safety, cartilage targeting, and high-efficiency for miR-140 based on articular cartilage characteristics. In addition, CPCs are mainly dispersed in the cartilage surface, while OA cartilage injury also begins from this layer, it is therefore essential to emphasize early intervention of OA. Conclusion: miR-140 has the potential to activate CPCs and promote the repair of cartilage injury in early OA, and it is of great clinical significance to further explore the role of miR-140 in OA etiology and to develop new OA treatment strategies based on miR-140.