Previous studies have demonstrated that extracorporeal shock wave therapy (ESWT) could accelerate diabetic wound healing and that the inhibition of glycogen synthase kinase-3β (GSK-3β) is involved in epithelial differentiation during wound healing. This study investigated whether the enhancement of diabetic wound healing by ESWT is associated with the GSK-3β-mediated Wnt/β-catenin signaling pathway. A dorsal skin wounding defect model using streptozotocin-induced diabetic rodents was established. Rats were divided into 4 groups: group 1, normal controls without diabetes; group 2, diabetic controls without treatment; group 3, diabetic rats receiving ESWT; and group 4, rats receiving 6-bromoindirubin-3′oxime (BIO), a GSK-3β inhibitor, to trigger Wnt/β-catenin signaling. Tissue samples were collected and analyzed by immunohistochemical (IHC) staining and quantitative RT-PCR. The ESWT and BIO-treated groups both exhibited significant promotion of wound healing compared to the healing in controls without treatment. RT-PCR analysis of Wnt-1, -3a, -4, -5a, and -10 and β-catenin expression showed significantly increased expression in the ESWT group. The IHC staining showed that Wnt-3a and -5a and β-catenin levels were significantly increased in the ESWT and BIO treatment groups compared to the control groups. ESWT enhancement of diabetic wound healing is associated with modulation of the GSK-3β-mediated Wnt/β-catenin signaling pathway.

Large bone fractures with segmental defects are a vital phase to accelerate bone integration. The present study examined the role of supercritical carbon dioxide (scCO2) decellularized bone matrix (scDBM) seeded with allogeneic adipose-derived mesenchymal stem cells (ADSC) as bio-scaffold for bone regeneration. Bio-scaffold produced by seeding ADSC to scDBM was evaluated by scanning electron microscopy (SEM). Rat segmental femoral defect model was used as a non-union model to investigate the callus formation in vivo. Histological analysis and osteotomy gap closure in the defect area were analyzed at 12 and 24 weeks post-surgery. Immunohistochemical expression of Ki-67, BMP-2 and osteocalcin was evaluated to assess the ability of new bone formation scDBM. ADSC was found to attach firmly to scDBM bioscaffold as evidenced from SEM images in a dose-dependent manner. Callus formation was observed using X-ray bone imaging in the group with scDBM seeded with 2 × 106 and 5 × 106 ASCs group at the same time-periods. H&E staining revealed ASCs accelerated bone formation. IHC staining depicted the expression of Ki-67, BMP-2, and osteocalcin was elevated in scDBM seeded with 5 × 106 ASCs group at 12 weeks after surgery, relative to other experimental groups. To conclude, scDBM is an excellent scaffold that enhanced the attachment and recruitment of mesenchymal stem cells. scDBM seeded with ASCs accelerated new bone formation.

Far-infrared ray (FIR) therapy has been applied in the tissue regeneration field. Studies have revealed that FIR could enhance wound healing. However, the biological effects of FIR on diabetic wounds remain unclear. Our study aims to investigate whether FIR could accelerate diabetic wound healing and analyze the biomechanisms. A dorsal skin defect (area, 6 × 5 cm2) in a streptozotocin (STZ)-induced diabetes rodent model was designed. Thirty-two male Wistar rats were divided into 4 groups (n = 8 each subgroup). Group 1 consisted of sham, non-diabetic control; group 2, diabetic control without treatment; group 3, diabetic rats received 20 min FIR (FIR-20, 20 min per session, triplicate/weekly for 4 weeks) and group 4, diabetic rats received 40 min FIR (FIR-40, 40 min per session, triplicate in one week for 4 weeks). The wound healing was assessed clinically. Skin blood flow was measured by laser Doppler. The vascular endothelial growth factor (VEGF), 8-hydroxy-2-deoxyguanosine (8-OHdG), eNOS, and Ki-67, were analyzed with immunohistochemical (IHC) staining. Laser Doppler flowmetry analysis of the blood flow of wounding area revealed the blood flow was higher in diabetic rats who received 40 min FIR (FIR-40) as compared to that in FIR-20 group. The wounding area was significantly reduced in the FIR-40 group than in the diabetic control groups. Histological findings of peri-wounding tissue revealed a significant increase in the neo-vessels in the FIR-treated groups as compared to the controls. IHC staining of periwounding biopsy tissue showed significant increases in angiogenesis expressions (VEGF, eNOS, and EGF), cell proliferation (Ki-67), and suppressed inflammatory response and oxygen radicles (CD45, 8-OHdG) expressions in the FIR-treated groups as compared to that in controls. Treatment with the optimal dosage of FIR significantly facilitated diabetic wound healing and associated with suppressed pro-inflammatory response and increased neovascularization and tissue regeneration.