BACKGROUND: The growth behaviors of cells on the biomaterials scaffold may be affected by the topography, pore size, wettability, porosity and other factors.OBJECTIVE: This research is aimed to observe the growth and proliferation of Schwann cells in silk fibroin scaffolds with different pore sizes. METHODS: Two kinds of silk fibroin scaffolds with different pore sizes were prepared, including a large pore size scaffold (pore size 50-60 μm) and a small pore size scaffold (pore size 10-20 μm). Schwann cells (R3 [33-10ras3]) served as seed cells and incubated in 37 ℃, 5% CO2 incubation box. When cells filled up the culture bottle bottom and formed a dense monolayer, they were digested and the cell concentration adjusted, then Schwann cells were seeded onto the surface of the porous silk fibroin scaffolds with different pore sizes. After seven days of co-culture, the growth and proliferation of Schwann cells were observed under scanning electron microscope.RESULTS AND CONCLUSION: The growth of Schwann cells on the surface of silk fibroin scaffolds with different pore sizes was varied. On the surface of small pore size scaffold (10-20 μm), the cell density was low, while the phenotype of cells was bipolar, cells arranged in parallel or linked as the cell chains. On the surface of large pore size scaffold (50-60 μm), more cells could be seen, but most of the cells were in the shape of single sphere, cells clustered on the surface of the porous scaffold or aggregated as a bunch of grape at the bottom of pores. Only few cells were bipolar and lied on the ridge between the pores. The result showed that the pore size of porous silk fibroin scaffolds is an influential factor for the growth and adhesion of Schwann cells. Schwann cells are conducive to grow on the scaffolds with pore size larger than cell body diameter.

Objective: To summarize the measures and experience of treatment in mass extremely severe burn patients. Methods: The clinical data and treatment of 8 extremely severe burn patients in August 2 Kunshan factory aluminum dust explosion accident who were admitted in the 100th Hospital of PLA on August 2nd, 2014, were retrospectively analyzed. There were 4 males and 4 females, aging 22-45 (34±7) years, with total burn area of 55%-98% [(89±15)%] total body surface area (TBSA) and full-thickness burn area of 45%-97% [(80±21)%] TBSA. All the 8 patients were accompanied with severe shock, inhalation injury, and blast injury. According to the requirements of former PLA General Logistics Department and Nanjing Military Command, a treatment team was set up including a special medical unit and a special care unit, with Chai Jiake from the First Affiliated Hospital of PLA General Hospital as the team leader, Zheng Qingyi from the 175th Hospital of PLA (the Affiliated Dongnan Hospital of Xiamen University) as the deputy leader, the 100th Hospital of PLA as the treatment base, and burn care, respiratory, nephrology, nursing specialists from the First Affiliated Hospital of PLA General Hospital, and the burn care experts and nursing staff from the 180th Hospital of PLA, 118th Hospital of PLA, 98th Hospital of PLA, and 175th Hospital of PLA, and nurses from the 85th Hospital of PLA, 455th Hospital of PLA, 101th Hospital of PLA, 113th Hospital of PLA as team members. Treatment strategies were adopted as unified coordination by the superior, unified responsibility of team leader, division of labor and cooperation between team members, and multidisciplinary cooperation led by department of burns. With exception of one patient who received deep vein catheterization before admission, the other 7 patients were treated with deep vein catheterization 0.5 to 3.0 hours after admission to correct hypovolemic shock as soon as possible. Eight patients received tracheotomy, and 7 patients were treated with mechanical ventilation by ventilator in protective ventilation strategy with low tide volume and low volume pressure to assist breathing. Fiberoptic bronchoscopy was done one to three times for all the 8 patients to confirm airway injuries and healing status. Escharectomy and Meek dermatoplasty in the extremities of all the 8 patients were performed 3 to 6 days after injury for the first time. Escharectomy, microskin grafting, and covering of large pieces of allogeneic skin on the trunks of 4 patients were performed 11 to 16 days after injury for the second time. The broad-spectrum antibiotics were uniformly used at first time of anti-infective therapy, and then the antibiotics species were adjusted in time. The balance of internal environment was maintained and the visceral functions were protected. One special care unit was on responsibility of only one patient. Psychological intervention was performed on admission. The rehabilitative treatment was started at early stage and in company with the whole treatment. Results: Acute renal injury occurred in 5 patients within 36 hours after injury and their renal function was restored to normal 4 days after injury due to active adjustment of fluid resuscitation program. No pulmonary complications, such as severe pulmonary infection and ventilator-associated pneumonia, occurred in the survived patients. One of the 8 patients died, and the other 7 patients were cured successfully. The wounds were basically healed in 2 patients in 26 or 27 days by 2 or 3 times of operation, and in 5 patients by 4 or 5 times of operation. The basic wound healing time was 26-64 (48±15) days for all the 7 patients. Conclusions Treatment strategies of unified coordination by the superior, unified responsibility of team leader, division of labor and cooperation between team members, and multidisciplinary cooperation led by department of burns are the bases to successful treatment. Correcting shock as soon as possible is the prerequisite and closing wound as soon as possible is the key to successful treatment. Comprehensive treatment measures, such as maintaining and regulating the function of viscera, improving the body immunity, and preventing and treating the complications, are the important components to successful treatment. It is emphasized that in the treatment of mass extremely severe burn patients, specialist burn treatment should always be in the dominant position, and other related disciplines may play a part in auxiliary function.