Bone Regenerative Effect of Injectable Hypoxia Preconditioned Serum-Fibrin (HPS-F) in an Ex Vivo Bone Defect Model.

Biofunctionalized hydrogels are widely used in tissue engineering for bone repair. This study examines the bone regenerative effect of the blood-derived growth factor preparation of Hypoxia Preconditioned Serum (HPS) and its fibrin-hydrogel formulation (HPS-F) on drilled defects in embryonic day 19 chick femurs. Measurements of bone-related growth factors in HPS reveal significant elevations of Osteopontin, Osteoprotegerin, and soluble-RANKL compared with normal serum (NS) but no detection of BMP-2/7 or Osteocalcin. Growth factor releases from HPS-F are measurable for at least 7 days. Culturing drilled femurs organotypically on a liquid/gas interface with HPS media supplementation for 10 days demonstrates a 34.6% increase in bone volume and a 52.02% increase in bone mineral density (BMD) within the defect area, which are significantly higher than NS and a basal-media-control, as determined by microcomputed tomography. HPS-F-injected femur defects implanted on a chorioallantoic membrane (CAM) for 7 days exhibit an increase in bone mass of 123.5% and an increase in BMD of 215.2%, which are significantly higher than normal-serum-fibrin (NS-F) and no treatment. Histology reveals calcification, proteoglycan, and collagen fiber deposition in the defect area of HPS-F-treated femurs. Therefore, HPS-F may offer a promising and accessible therapeutic approach to accelerating bone regeneration by a single injection into the bone defect site.

Hypoxia Preconditioned Serum (HPS) Promotes Proliferation and Chondrogenic Phenotype of Chondrocytes In Vitro.

Autologous chondrocyte implantation (ACI) for the treatment of articular cartilage defects remains challenging in terms of maintaining chondrogenic phenotype during in vitro chondrocyte expansion. Growth factor supplementation has been found supportive in improving ACI outcomes by promoting chondrocyte redifferentiation. Here, we analysed the chondrogenic growth factor concentrations in the human blood-derived secretome of Hypoxia Preconditioned Serum (HPS) and assessed the effect of HPS-10% and HPS-40% on human articular chondrocytes from osteoarthritic cartilage at different time points compared to normal fresh serum (NS-10% and NS-40%) and FCS-10% culture conditions. In HPS, the concentrations of TGF-beta1, IGF-1, bFGF, PDGF-BB and G-CSF were found to be higher than in NS. Chondrocyte proliferation was promoted with higher doses of HPS (HPS-40% vs. HPS-10%) and longer stimulation (4 vs. 2 days) compared to FCS-10%. On day 4, immunostaining of the HPS-10%-treated chondrocytes showed increased levels of collagen type II compared to the other conditions. The promotion of the chondrogenic phenotype was validated with quantitative real-time PCR for the expression of collagen type II (COL2A1), collagen type I (COL1A1), SOX9 and matrix metalloproteinase 13 (MMP13). We demonstrated the highest differentiation index (COL2A1/COL1A1) in HPS-10%-treated chondrocytes on day 4. In parallel, the expression of differentiation marker SOX9 was elevated on day 4, with HPS-10% higher than NS-10/40% and FCS-10%. The expression of the cartilage remodelling marker MMP13 was comparable across all culture conditions. These findings implicate the potential of HPS-10% to improve conventional FCS-based ACI culture protocols by promoting the proliferation and chondrogenic phenotype of chondrocytes during in vitro expansion.

In Vitro Comparison of Lymphangiogenic Potential of Hypoxia Preconditioned Serum (HPS) and Platelet-Rich Plasma (PRP).

Strategies for therapeutic lymphangiogenesis are gradually directed toward the use of growth factor preparations. In particular, blood-derived growth factor products, including Hypoxia Preconditioned Serum (HPS) and Platelet-rich Plasma (PRP), are both clinically employed for accelerating tissue repair and have received considerable attention in the field of regenerative medicine research. In this study, a comparative analysis of HPS and PRP was conducted to explore their lymphangiogenic potential. We found higher pro-lymphangiogenic growth factor concentrations of VEGF-C, PDGF-BB, and bFGF in HPS in comparison to normal serum (NS) and PRP. The proliferation and migration of lymphatic endothelial cells (LECs) were promoted considerably with both HPS and PRP, but the strongest effect was achieved with HPS-40% dilution. Tube formation of LECs showed the highest number of tubes, branching points, greater tube length, and cell-covered area with HPS-10%. Finally, the effects were double-validated using an ex vivo lymphatic ring assay, in which the highest number of sprouts and the greatest sprout length were achieved with HPS-10%. Our findings demonstrate the superior lymphangiogenic potential of a new generation blood-derived secretome obtained by hypoxic preconditioning of peripheral blood cells-a method that offers a novel alternative to PRP.

Management of foot degloving injury with bilateral anterolateral thigh flaps.

Foot degloving injuries are frequently encountered by reconstructive surgeons as there are more and more vehicles on the road. The separation between the deep facia and the superficial skin often damage the blood supply of the cutaneous tissue, resulting skin defect and digit necrosis. In order to manage these challenging situations, reconstructive surgeons have explored various types of techniques. Our team have managed to cure one such patient through bilateral anterolateral thigh flaps, in which the two flaps cover the dorsal and plantar side respectively. The flaps survived uneventfully and second stage operation of defatting was consequently arranged. The patient obtained protective sensation and felt satisfied with the cosmetic outcome. With the development of microsurgery, bilateral anterolateral thigh flaps could be effectively adopted to manage foot degloving injuries.

The mini-incision technique for carpal tunnel release using nasal instruments in Chinese patients.

Treatment of carpal tunnel syndrome (CTS) remains a challenge for hand surgeons. Carpal tunnel release (CTR) using nasal instruments has the advantages of both endoscopy and open surgery. In this study we aimed to explore the effectiveness of CTR using nasal instruments in Chinese patients.We present a case series of 49 cases of idiopathic CTS treated with the mini-incision technique using nasal instruments. The average recovery days before return to normal work and complications were recorded. The mean grip strength, pinch strength, and sensation were evaluated. Subjective results were evaluated using the visual analogue scale (VAS), Levine Carpal Tunnel Syndrome Questionnaire (LCTSQ), Disabilities of the Arm, Shoulder, and Hand (DASH), and Medical Outcomes Study (MOS) 36-item short-form health survey (SF-36).The mean follow-up was 13 months. No return of symptoms or blood vessel injury occurred. The incidence of scar tenderness was only 8.1%, later pillar pain (after 4 weeks) was 18.4%, and average recovery time to return to normal work was 23.7 days. The mean grip strength, pinch strength, and sensation were significantly improved (P < .001). The VAS, LCTSQ, and DASH survey postoperative mean scores were lower than the preoperative scores (P < .001). SF-36 scores were significantly increased following surgery (P < .001).We conclude that the mini-incision technique for CTR using nasal instruments in Chinese patients is safe, effective, and low cost. It is worthwhile for the technique to be promoted and used.

Chronic sciatic nerve compression induces fibrosis in dorsal root ganglia.

In the present study, pathological alterations in neurons of the dorsal root ganglia (DRG) were investigated in a rat model of chronic sciatic nerve compression. The rat model of chronic sciatic nerve compression was established by placing a 1 cm Silastic tube around the right sciatic nerve. Histological examination was performed via Masson's trichrome staining. DRG injury was assessed using Fluoro Ruby (FR) or Fluoro Gold (FG). The expression levels of target genes were examined using reverse transcription­quantitative polymerase chain reaction, western blot and immunohistochemical analyses. At 3 weeks post­compression, collagen fiber accumulation was observed in the ipsilateral area and, at 8 weeks, excessive collagen formation with muscle atrophy was observed. The collagen volume fraction gradually and significantly increased following sciatic nerve compression. In the model rats, the numbers of FR­labeled DRG neurons were significantly higher, relative to the sham­operated group, however, the numbers of FG­labeled neurons were similar. In the ipsilateral DRG neurons of the model group, the levels of transforming growth factor­ß1 (TGF­ß1) and connective tissue growth factor (CTGF) were elevated and, surrounding the neurons, the levels of collagen type I were increased, compared with those in the contralateral DRG. In the ipsilateral DRG, chronic nerve compression was associated with significantly higher levels of phosphorylated (p)­extracellular signal­regulated kinase 1/2, and significantly lower levels of p­c­Jun N­terminal kinase and p­p38, compared with those in the contralateral DRGs. Chronic sciatic nerve compression likely induced DRG pathology by upregulating the expression levels of TGF­ß1, CTGF and collagen type I, with involvement of the mitogen­activated protein kinase signaling pathway.

[Clinical application of perforator propeller flaps with anastomosis of superficial veins].

OBJECTIVE: To investigate the clinical effect of anastomosis of superficial veins for improving the drainage of perforator propeller flaps. METHODS: From Sept. 2011 to Dec. 2012, 11 cases with soft tissue defects and chronic ulcer wound at extremities were treated with adjacent perforator propeller flaps, which were pedicled by the peroneal artery(5 cases), or the lateral supramalleolar artery(3 cases), or the ulnar artery (2 cases), or the posterior interrosseous artery (1 case). The wound size ranged from from 3.0 cm x 2. 5 cm to 11. 0 cm x 4. 0 cm, and the falps size ranged from 6 cm x 3 cm to 21 em x 5 cm. One superficial vein in all the flaps was anastomosed with superficial vein in the recipient area. The blood supply of the flaps were recorded after operation 1 - 3 months after operation, the fluency of anastomosed vein was detected by color Doppler ultrasound. Flap swelling evaluations were performed in early 3 months and later 3 - 6 months, and the results were classified into 4 grading degrees. 6 months later, Questionnaire of the flap aesthetic satisfactory was performed for seven patients during follow-up period. RESULTS: 9 flaps survived completely, two flaps had partial marginal skin necrosis in the distal end, which were both managed with surgical debridement, and both wounds healed in two months. 9 cases were followed up for more than 12 - 19 months. The early rsults of flap swelling evaluations were: I degree 0 case, II degree 8 cases, III degree 3 cases, IV degree 0 case, and the later results were: I degree 7 cases, II degree 4 cases, III degree 0 case, IV degree 0 case. The flaps had ideal appearance, good contour, and high aesthetic satisfactory (100%). The mean flap survival area rate of veins anastomosed was (98. 6 ± 9. 7) %. CONCLUSIONS: Perforator propeller flaps with anastomosis of superficial veins can improve the flap venous drainage, avoid transient venous venous congestion, so as to increase the flap survival. It is an effective way for improving the vein drainage.

Acetyl-L-carnitine attenuates okadaic acid induced tau hyperphosphorylation and spatial memory impairment in rats.

Tau hyperphosphorylation and memory deficit are characteristic alterations of Alzheimer's disease (AD). Protein phosphatases (PP) 2A plays a crucial role in AD-like lesions. Inhibition of PP2A through hippocampal injection of okadaic acid (OA) induces tau hyperphosphorylation and memory impairment of rats. By using this model, we explored in the present study the effects of acetyl-L-carnitine (ALCAR), a constituent of the inner mitochondrial membrane, on the memory retention, tau phosphorylation, and oxidative stress in rats. We found that pre-treatment of ALCAR (50 mg/d . rat, per os) for two weeks efficiently improved the OA-induced spatial memory retention impairment of the rats. ALCAR antagonized tau hyperphosphorylation at multiple AD sites and it abated the OA-induced PP2A inhibition and oxidative stress. Our study provides the first in vivo evidence that ALCAR can attenuate AD-like PP2A inhibition, tau hyperphosphorylation, and spatial memory deficit of the rats. It suggests that ALCAR may hold potential in AD treatment.