Biomineralized tetramethylpyrazine-loaded PCL/gelatin nanofibrous membrane promotes vascularization and bone regeneration of rat cranium defects.

Conventional electrospinning produces nanofibers with smooth surfaces that limit biomineralization ability. To overcome this disadvantage, we fabricated a tetramethylpyrazine (TMP)-loaded matrix-mimicking biomineralization in PCL/Gelatin composite electrospun membranes with bubble-shaped nanofibrous structures. PCL/Gelatin membranes (PG), PCL/Gelatin membranes containing biomineralized hydroxyapatite (HA) (PGH), and PCL/Gelatin membranes containing biomineralized HA and loaded TMP (PGHT) were tested. In vitro results indicated that the bubble-shaped nanofibrous surface increased the surface roughness of the nanofibers and promoted mineralization. Furthermore, sustained-release TMP had an excellent drug release efficiency. Initially released vigorously, it reached stabilization at day 7, and the slow-release rate stabilized at 61.0 ± 1.8% at 28 days. All membranes revealed an intact cytoskeleton, cell viability, and superior adhesion and proliferation when stained with Ghost Pen Cyclic Peptide, CCK-8, cell adhesion, and EdU. In PGHT membranes, the osteogenic and vascularized gene expression of BMSCs and human vascular endothelial cells was significantly upregulated compared with that in other groups, indicating the PGHT membranes exhibited an effective vascularization role. Subsequently, the membranes were implanted in a rat cranium defect model for 4 and 8 weeks. Micro-CT and histological analysis results showed that the PGHT membranes had better bone regenerative patterns. Additionally, the levels of CD31 and VEGF significantly increased in the PGHT membrane compared with those in other membranes. Thus, PGHT membranes could accelerate the repair of cranium defects in vivo via HA and TMP synergistic effects.

[Clinical application of veno-arteriolization of finger lateral vein for repairing severed finger tips].

OBJECTIVE: To investigate effect of veno-arteriolization of finger lateral vein for repairing severed finger tips. METHODS: From March 2007 to April 2012, 20 patients with severed finger tips were treated with veno-arteriolization of finger lateral vein after failure in anastomosing artery of finger over times. During operation, the dominant digital artery at proximal end and the dominant finger lateral vein at distal end was anastomosed as the blood supply, the non-superiorty finger lateral vein was anastomosed as the blood drainage. RESULTS: All flaps survived completely and achieved primary healing. 18 patients were successfully followed up for 6 to 12 months with satisfactory appearance and nail growth. Finger pulp was plump with good flexibility. The average length of nail was (15.6 +/- 2.7) mm and the average motion of DIP joint was (62 +/- 4) degrees. The average two point discrimination was (4.6 +/- 0.3) mm and the average sensation measurement was S3+. CONCLUSION: The veno-arteriolization of finger lateral vein is a valuable method for repairing severed finger tips, which can promote nail growth, and restore fingers motion and sensation.

[Repairing degloving injury of distal phalanx with homodigital bilobed flaps tiled].

OBJECTIVE: To study the methods and effectiveness of repairing degloving injury of the distal phalanx with homodigital bilobed flaps tiled. METHODS: Between April 2008 and June 2011, 40 patients (40 fingers) with degloving injury of the distal phalanx were treated, which were caused by machine. There were 30 males and 10 females, aged from 18 to 56 years (mean, 30 years). The time from injury to operation was 1-5 hours (mean, 2.5 hours). Affected fingers included index in 13 cases, middle finger in 11 cases, ring finger in 9 cases, and little finger in 7 cases. The defect area ranged from 3.0 cm x 2.0 cm to 5.5 cm x 3.8 cm. All cases complicated by pollution and exposure of tendon and phalanx, 5 cases by phalangeal fractures, and tendon insertion had no rupture. The end dorsal branches of digital artery island flaps and digital arterial island flaps were used in 14 cases, the end dorsal branches of digital artery island flaps and near dorsal branches of digital artery island flaps in 18 cases, and the end dorsal branches of digital artery island flaps and superficial palmar digital veins arterilization island flaps in 8 cases. The area of the upper flaps ranged from 2.0 cm x 1.5 cm to 2.6 cm x 2.2 cm and the area of the next leaf flaps ranged from 2.5 cm x 2.0 cm to 3.5 cm x 2.5 cm. The donor sites were covered with free flaps. RESULTS: Flap blister occurred in 13 cases and vascular crisis in 3 cases. The flaps survived in 40 cases, wound healing by first intention was achieved in 38 cases, and by second intention in 2 cases. The donor skin-grafting was survival. After operation, 30 patients were followed up 8 to 20 months with an average of 10.6 months. The flaps had satisfactory appearance and soft texture, and the finger tip had no touch pain. The sensory function of the flaps was restored at 4-6 weeks after operation; two-point discrimination was 6.0 to 10.0 mm in 24 flaps at 12-15 months. According to the total active movement (TAM) evaluation system introduced by the American Society for Surgery of the Hand in 1975, the results were excellent in 27 cases, good in 2 cases, and fair in 1 case, and the excellent and good rate was 96.7%. CONCLUSION: The homodigital bilobed flaps tiled for degloving injury of the distal phalanx is simple and easy-to-operate with less injury.