[Objective]To sturdy the biological responses of osteoblast-like cells in different maturation stages under shear flow.[Method]Flow chamber system was used to apply shear flow stimulation of 4.62dyn?s/cm~2 for 2 hours on osteoblast-like cell MC3T3-E1 of different maturation stage induced by osteogenic media,and then samples for dsDNA content and ALP activity analysis were collected.[Result]On 24 hours after simulation,there was not obvious change of ALP activity with non-osteogenic inducing group,an increase was observed in the group of 4 days of differentiation,while an decrease in the group of 8 days of differentiation.[Conclusion]Biological responses of osteoblast-like cells in different maturation stages under shear flow is quite different,and this may be an important role in bone growth and reconstruction.

Objective To explore the feasibility and clinic outcome of the modified latissimus dorsi flap when it is used to repair huge soft tissue defects in lower limbs.Methods The latissimus dorsi muscle is rich blood supply and available for harvest huge areas.According to these characteristics the modified latissimus dorsi flap was designed:a limited latissimus dorsi skin flap with a large area of latissimus dorsi muscle flap,skin graft area was transferred from donor-site to recipient-site.From April 2009 to August 2011,ten patients with large soft tissue defects in lower limbs were treated with modified latissimus dorsi flap.The size of skin and soft tissue defects range from 19 cm × 10 cm to 32 cm × 16 cm.Ten modified latissimus dorsi flaps had been used for coverage of these wounds,which were amplified 1-2 cm compared with the corresponding wounds.The size of skin flap was 20 cm × 6 cm-33 cm × 10 cm which was allowable to get direct closure of donor-site wounds.Results All the flaps and skin graft survived completely with no complication.Donor-site and recipient-site were primary closed and healing in all patients.All of the patients had got follow-up from 6 months to 36 months.All flaps survived with excellent color and quality,and no extremely fat contour.The results in donor site were satisfying and only left liner scar.It has no effect in the shoulder function.Conclusion The modified latissimus doris flap can provide with a huge amount of skin and soft tissue and be designed in various ways.It is a safe and reliable way to reconstruct huge skin and soft tissue defect in lower limbs.

[Abstract ] Objective At present, the majority of injectable tissue engineering bones or carrier stents are gel , whose surface area , intensity, and hardness cannot satisfy the requirements of the repair of complex and varied bone and cartilage defects .This paper evaluated the new injectable microspherical porous chitosan/biological properties of the hydroxyapatite ceramic scaffold . Methods Injectable porous chitosan /hydroxyapatite composite microspheres with mass fractions of 30%, 50%, and 70% were prepared respectively . The hydroxyapatite ceramic ball was obtained by sintering with liquid nitrogen freezing ( liquid nitrogen group ) or without liquid nitrogen pro-cessing ( non-liquid nitrogen group ) as a new carrier of bone tissue engineering scaffold material .The microstructure of the scaffold was observed and the porosity measured under the scanning electron microscope .The mechanical properties were determined through biome-chanical experiments.Human umbilical vein endothelial cells (HUVECs) were grown in the porous chitosan/hydroxyapatite ceramic scaf-fold followed by observation of the growth of the cells and validation of the biological fusion of the scaffold . Results No difference was observed with the naked eye in the ceramic scaffold of different mass fractions in the liquid nitrogen and non -liquid nitrogen groups . Scanning electron microscopy exhibited spherical shape , uniform size, and regular morphology of the ceramic scaffolds in both groups .A large number of irregular pores were seen in the surface of the microspherical ceramic scaffolds treated with liquid nitrogen but not in the surface of those not treated .With increased mass percentage of chitosan/hydroxyapatite , the internal pores were reduced and the interior structure compacted.In the liquid nitrogen group, the scaffold of 50%mass fraction had a significantly larger diameter ([0.48 ±0.11] mm), higher compression intensity ([1.75 ±0.14] MPa), and lower porosity ([79 ±2]%) than that of 30%mass fraction ([0.40 ± 0.08] mm, [1.21 ±0.12] MPa, and [87 ±1]%) (all P<0.05).Electron microscope scanning revealed well -grown HUVECs with multiple synapses in the porous tricalcium phosphate scaffold. C onclusion The porous chitosan /hydroxyapatite ceramic scaffold of 50%mass fraction treated with liquid nitrogen , with its strong mechanical intensity and high biological fusibility , can be used as a new carrier of bone tissue engineering scaffolds .

Objective:To explore the feasibility and clinical effects of using free thinned deep inferior epigastric artery perforator flap to repair extensive soft tissue defects in extremities.Methods:From April 2010 to January 2014, 12 patients with extensive soft tissue defect in extremities after trauma, including 10 males and 2 females, aged 21 to 48 years, 6 patients with defect in the back of wrist and 6 patients with defect in ankle were admitted to the Department of Bone Microsurgery of Xi′an Honghui hospital. After debridement, the size of soft tissue defect ranged from 15.0 cm×4.5 cm to 28.0 cm×11.0 cm. The free thinned deep inferior epigastric artery perforator flap was designed, cut and transferred for reconstruction, with size of 15.0 cm×5.0 cm to 29.0 cm×12.0 cm. The flap thickness ranged from 4.0 to 6.5 cm before defatting, and was 0.6 to 0.9 cm after defatting. All the donor sites of flaps were closed directly by suturing. The flap survival and the appearance and function of flap and donor site were observed during follow-up.Results:All the flaps survived smoothly after surgery. During follow-up of 10 to 42 months, the flaps showed no bloat in appearance, no further flap revision or defatting procedures were required, the distance of static 2-point discrimination was 11 to 17 mm (14.5 mm on average). The abdominal function of patients was not affected, and no postoperative abdomen hernia or ulceration was noted.Conclusions:The free thinned deep inferior epigastric artery perforator flap is thin and suitable for repairing extensive soft tissue defects in extremities with very good outcomes.