Is platelet-rich plasma an ideal biomaterial for arthroscopic rotator cuff repair? A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Recently, many authors have reported the effects of platelet-rich plasma (PRP) on rotator cuff repair. Whether PRP treatment during arthroscopic rotator cuff repair improves tendon healing rates or restores full function remains unknown. The purpose of this meta-analysis was to evaluate the clinical improvement and radiological outcomes of PRP treatment in patients undergoing arthroscopic rotator cuff repair. METHODS: PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were searched. The study included only level 1 or 2 randomized controlled trials (RCTs) that compared the injection of platelet-rich plasma or platelet-rich fibrin matrix. The methodological quality of the trials was assessed using the Cochrane Handbook for Systematic Reviews of Interventions, 5.3. Continuous variables were analysed using the weighted mean difference, and categorical variables were assessed using relative risks. P < 0.05 was considered statistically significant. RESULTS: The meta-analysis revealed a lower retear rate following PRP treatment than that following the control method (mean difference, 1.10; 95% CI, 1.03 to 1.18; P = 0.004). Constant shoulder scores improved with PRP (mean difference, 2.31; 95% CI, 1.02 to 3.61; P = 0.0005). PRP treatment also resulted in higher UCLA scores (mean difference, 0.98; 95% CI, 0.27 to 1.69; P = 0.007), and simple shoulder test scores were improved (mean difference, 0.43; 95% CI, 0.11 to 0.75; P = 0.008). Finally, lower visual analogue scale scores were observed with PRP augmentation (mean difference, - 0.35; 95% CI, - 0.57 to - 0.13; P = 0.002). CONCLUSIONS: The current systematic review and meta-analysis reveals that PRP treatment with arthroscopic repair of rotator cuff tears decreases the retear rate and improves the clinical outcomes. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42016048416.

The effective mode of growth and differentiation factor-5 in promoting the chondrogenic differentiation of adipose-derived stromal cells.

Our study aimed to find out the most effective mode for chondrogenic differentiation based on time, dose and culture method. ADSCs were cultured and identified by CD44, CD49d, and CD106 immumohistochemical staining method, and their differentiation potential to chondrocyte were detected by Alizarin red staining. ADSCs induced by different concentrations of GDF-5 for chondrogenic differentiation were detected by blue and toluidine blue staining and collagen type II and X immumohistochemical staining. The expression of collagen I, II, X and aggrecan gene in GDF-induced ADSCs cultured in 2- and 3-dimension was identified by real-time PCR. Cell microstructure and proliferation in three-dimensional scaffolds at day 7, 14, 21 and 28 were analyzed by scanning electron microscopy and MTS assay. The ADSCs were successfully identified by CD44 and CD49d, and their differentiation potential was detected by Alizarin red staining. Real-time PCR showed that collagen and aggrecan were expressed at high levels in 100 or 200 ng/mL GDF-5 treated cells. The collagen types (I, II) and aggrecan genes were higher expressed in GDF-5 induced scaffold group than that in monolayer group. MTS showed that the cell counts were not significantly different among different treated time. Both collagen type II and aggrecan gene were highly expressed at day 14, while collagen types I and X gene expressions peaked at day 21 and 28. The 100 ng/mL GDF-5 is effective and cost-effective for chondrogenic differentiation when cultured at day 14 in vitro under three-dimensional culture conditions.

Identification of genes associated with the differentiation potential of adipose-derived stem cells to osteocytes or myocytes.

Adipose-derived stem cells (ADSCs) have been considered as the optimal cells for regenerative medicine because ADSCs have the potential of multi-directional differentiation. To study the mechanisms of ADSCs differentiation, we analyzed microarray of GSE37329. GSE37329 was downloaded from Gene Expression Omnibus including 3 ADSCs, 2 ADSCs-derived osteocytes, and 2 ADSCs-derived myocytes samples. The differentially expressed genes (DEGs) were screened using limma package. Their underlying functions were predicted by gene ontology and pathway enrichment analyses. Besides, the interaction relationships of the proteins encoded by DEGs were obtained from STRING database, and protein-protein interaction (PPI) network was constructed using Cytoscape. Furthermore, modules analysis of PPI network was performed using MCODE in Cytoscape. We screened 662 and 484 DEG separately for the ADSCs-derived osteocytes and myocytes compared with ADSCs. There were 205 common up-regulated and 128 common down-regulated DEGs between the two groups. Function enrichment indicated that these common DEGs, especially, VEGFA, FGF2, and EGR1 may be related to cell differentiation. PPI network for common DEGs also suggested that VEGFA (degree = 29), FGF2 (degree = 17), and EGR1 (degree = 12) might be more important because they had higher connectivity degrees, and they might be involved in cell differentiation by interacting with other genes in module A (e.g., EGR1-NGF and EGR1-LEP), and B (e.g., VEGFA-PDGFD). Additionally, the IGF1 and BTG1 may be, respectively, specific for osteocytes and myocytes differentiation. VEGFA, PDGFD, FGF2, EGR1, NGF, LEP, IGF1, and BTG1 might serve as target genes in regulating ADSCs differentiation.