Construction of Ang2-siRNA chitosan magnetic nanoparticles and the effect on Ang2 gene expression in human malignant melanoma cells.

The aim of the present study was to construct angiopoietin-2 (Ang2)-small interfering (si)RNA chitosan magnetic nanoparticles and to observe the interference effects of the nanoparticles on the expression of the Ang2 gene in human malignant melanoma cells. Ang2-siRNA chitosan magnetic nanoparticles were constructed and transfected into human malignant melanoma cells in vitro. Red fluorescent protein expression was observed, and the transfection efficiency was analyzed. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to assess the inhibition efficiency of Ang2 gene expression. Ang2-siRNA chitosan magnetic nanoparticles were successfully constructed, and at a mass ratio of plasmid to magnetic chitosan nanoparticles of 1:100, the transfection efficiency into human malignant melanoma cells was the highest of the ratios assessed, reaching 61.17%. RT-qPCR analysis showed that the magnetic chitosan nanoparticles effectively inhibited Ang2 gene expression in cells, and the inhibition efficiency reached 59.56% (P<0.05). Ang2-siRNA chitosan magnetic nanoparticles were successfully constructed. The in vitro studies showed that the nanoparticles inhibited Ang2 gene expression in human malignant melanoma tumor cells, which laid the foundation and provided experimental evidence for additional future in vivo studies of intervention targeting malignant melanoma tumor growth in nude mice.

[Anatomic study and application of TRAM flap with partial preservation of abdominal rectus muscle in the breast reconstruction].

OBJECTIVE: To investigate the feasibility and effectiveness of transverse rectus abdominis musculocutaneous (TRAM) flap with partial preservation of abdominal rectus muscle based on the anatomic study in cadavers. METHODS: 5 adult female cadavers which provided by department of anatomy of Fujian Medical University were dissected after injection with medical red latex from the starting point of the inferior epigastric artery and superior epigastric artery. The TRAM flap with partial preservation of lateral abdominal rectus muscle were dissected for breast reconstruction. The location, route, branches and anastomosis of inferior and superior epigastric arteries were observed. Based on the anatomic study, breast reconstruction were performed in 8 cases with muscle-sparing TRAM flaps. RESULTS: The inferior epigastric artery arises from external iliac artery (9/10, 90%) or femoral artery (1/10, 10%) at the joint point between the internal third and lateral two third. There are extensive anastomoses between superior and inferior epigastric arteries above the umbilicus, mostly between the 2cm below the first tendinous intersection and umbilical level. From Sept. 2009 to Sept. 2010, 8 cases received breast reconstruction with muscle-sparing TRAM flap. The patients were followed up for 3 months to one year. Fibrosis happened in subcutaneous fat at flap IV zone in 2 cases, borderline necrosis and subcutaneous fat liquefaction occurred in some areas of flap IV zone in 2 cases, which healed after debridement. The other 4 cases healed with no complication. Except for unsatisfied shape in one case, good result achieved in 7 cases. There was no abdominal weakness, hemia or other complication. CONCLUSIONS: It is an effective and safe method in breast reconstruction with muscle-sparing TRAM flap. It is practical with comparatively short operation time and less morbidity in donor site.

[Auricular reconstruction for concha-type microtia].

OBJECTIVE: To investigate the method of auricular reconstruction for concha-type microtia. METHODS: Two-staged auricular reconstruction was applied in 13 cases (14 ears) with concha-type microtia. The cartilage auricular framework was fabricated and implanted in the first stage, followed by ear elevation and cranio-auricle angle formation at the second stage. RESULTS: The patients were followed up for 2 months to 2 years with satisfactory aesthetic result. The reconstructed ears had a good appearance and position, and were symmetric to the healthy ears. CONCLUSIONS: The two-staged auricular reconstruction with autologous cartilage framework is ideal for concha-type microtia.

[Construction of recombinant lentiviral vector of Tie2-RNAi and its influence on malignant melanoma cells in vitro].

OBJECTIVE: To construct lentivector carrying Tie2-Small interfering RNA (SiRNA), so as to study its influence on malignant melanoma cells. METHODS: Recombinant plasmid pSilencer 1.0-U6-Tie2-siRNA and plasmid pNL-EGFP were digested with XbaI, ligated a target lentiviral transfer plasmid of pNL-EGFP-U6-Tie2-I or pNL-EGFP-U6-Tie2-II, and then the electrophoresis clones was sequenced. Plasmids of pNL-EGFP-U6-Tie2-I and pNL-EGFP-U6-Tie2-II were constructed and combined with pVSVG and pHelper, respectively, to constitute lentiviral vector system of three plasmids. The Lentiviral vector system was transfected into 293T cell to produce pNL-EGFP-U6-Tie2- I and pNL-EGFP-U6-Tie2-II lentivirus. Then the supernatant was collected to determine the titer. Malignant melanoma cells were infected by both lentiviruses and identified by Realtime RT-PCR to assess inhibitory efficiency. RESULTS: The recombinant lentiviral vectors of Tie2-RNAi were constructed successfully which were analyzed with restriction enzyme digestion and identified by sequencing. And the titer of lentiviral vector was 8.8 x 10(3)/ml, which was determined by 293T cell. The results of Realtime RT-PCR demonstrated that the lentiviral vectors of Tie2-RNAi could infect malignant melanoma cells and inhibit the expression of Tie2 genes in malignant melanoma cells (P<0.01). There was no significant difference in the expression level (P>0.05) between the two lentiviral vectors of Tie2-RNAi. CONCLUSIONS: Lentivector carrying Tie2-SiRNA can be constructed successfully and inhibit the expression of Tie2 gene in vitro significantly. The study will supply the theory basis for the further research on the inhibition of tumor growth in vivo.

[Experimental study of repairing skull defect with autogenous cranial bone dust].

OBJECTIVE: To build animal model of skull defect for the basic research of skull defects reconstruction with autogenous cranial bone dust and its relevance to the clinical application. METHODS: Three full-thickness parietal skull defects (A, B and C) were created in 30 New Zealand white rabbits. The size of all the defects was 1 cm in diameter. The defect A was left untreated as control. Defects B and C were reconstructed with autogenous cranial bone dust. Two pieces of pyroxylin membrane were placed on the top and bottom of the defect B. every 10 rabbits were killed for analysis at 4, 8, 12 weeks after operation. RESULTS: Defect A was largely repaired with connective tissue. Defect B was repaired rapidly with newly formed cancellous bone in the early period, but the following process of the growth, remodeling and maturing of the newly-formed cancellous bone was slowly. The bone ingrowth in defect C was more mature, but could not repair the defect completely, especially in the central zone. The grafted bone dust was absorbed gradually. Active angiogenesis could be observed in the newly formed bone. For the same defect, new bone had a greater amount of calcium at 12 weeks than at 4 and 8 weeks after operation (P < 0.05). And the calcium content of new bone was higher in defect C than in defect B at 8, 12 weeks after operation (P < 0.05). CONCLUSIONS: The osteogenesis and angiogenesis are closely related to the time and location. The pyroxylin membrane can significantly promote the formation of cancellous bone in defect with autogenous bone dust graft during the early period.

[The reconstruction of funnel chest deformity with the reversed transplantation of sternum-costicartilage flap carried by the abdominal rectus pedicle].

OBJECTIVE: To investigate the reconstructive operative procedures of funnel chest with "sternum-costicartilage" flap carried by the abdominal rectus pedicle. METHODS: (1) In accordance with the lesioned area of funnel-like depressed deformity of anterior thoracic wall, a perpendicular median incision was designed and made; (2) The "sternum-costicartilage" flap carrying the abdominal rectus pedicle was used and reversed and transplanted to reconstruct severe funnel chest deformity. RESULTS: The procedure was used in 7 cases from 1999 to 2005. The results of surgery were satisfactory. There were no recurrence after operation. CONCLUSIONS: The procedure reported here is rather safe, solid and sound with good therapeutic results, and is of great value in clinical practice.