ABSTRACT
Objective After hydrogen bonding between collagen ( COL) and silk fibroin ( SF ) at different concentrations, a composite scaffold with adjustable stiffness was prepared by combining with gel system, and its physical and chemical properties were characterized. Methods SF with different qualities was dissolved in sodium alginate (SA) solution, then COL solution at different concentration and calcium carbonate ( CaCO3 ) powder were added. The hydrogels of SC1, SC2, and SC3 groups were obtained by taking out the mixed solution and adding some gluconic acid lactone ( GDL) powder, and different SF scaffolds were obtained after freeze drying. Results The SF scaffolds with adjustable stiffness were successfully prepared. The compression moduli of SC1, SC2, and SC3 groups were (17. 31±2. 73), (24. 12±1. 81), (32. 54±1. 81) kPa, respectively. The innerstructure of the scaffolds was observed. From SC1 group to SC3 group, pores of the scaffolds were smaller and fewer, and hydrophilicity of the materials become better and better. Conclusions Three-dimensional ( 3D) porous scaffolds with different matrix stiffness can be prepared by changing the concentration of SF and COL solution. The concentration of SF and COL is proportional to the compression modulus, water absorption, water retention and swelling rate of SF scaffolds, while inversely proportional to porosity. The findings of this study are expected to provide theoretical guidance for construction of scaffolds with appropriate matrix stiffness for inducing osteogenic differentiation of mesenchymal stem cells
ABSTRACT
To determine the treatment result of Adhesive otitis media, 105 cases(129 cars) were analysed retrospectively. Of them, 70 ears( 54 %) had a small air - room at the tympanic opening of eustachian tube, 12 ears had obstructed eustachian tube. The classification of adhesive otitis media and selection of proper measures were discussed. Further improvement of hearing was still a puzzled problem.
ABSTRACT
Objective To explore and assess NiTi shape memory alloys stent intraeustachian tube placement prevent and treat adhesive otitis media. Methods The patients were divided into 3 groups (A:56 cases of adhesive otitis media, B:27 cases of otitis media with effusion, C:52 cases as control). In all cases of eustachian orifices were inspected by endoscope. 2 autopsy eustachian tubes were dissected. NiTi shape memory alloys stent intraeustachian tube plasment was perfomed in 8 cases to prevent and treat adhesions of middle ear with seld-designed . Results The eustachian orifice can be divided into three types: wide, narrow and fissure like instolle. In group A, wide, narrow, fissure like showed 20, 31, 5; respectively in group B: 9, 13, 5; in group C: 45, 7, 0. There was significant difference in three gorup (A,B, versus C ? 2=29.66,25.44 respectively, P0.05). Autopsy of eustachian tube: cartilage length was 30 mm, trapeziform, floor width was 11 mm, tip width was 4 mm. 4 cases of adhesive otitis media gained good ventilation as during valsalva method with audiometry promotion 15-30 dB after NiTi shape memory alloys stent placements. Two of 4 cases of otitis media with refractory effusion, gained A-B gap close, follow up over 12 months; the other was good at valslva's and gave up ventilation tube. Eight case had no patulous and any side-effect after NiTi shape memory alloys placement. Conclusions Adhesive otitis media can be prevented and treated by placing NiTi shape memory alloys stent with no patulous or other side-effect.