BACKGROUND:Based on the original advantages of silk fibroin, positive charged water-soluble chitosan modified silk fibroin is modified on surface and could improve celladhesion on the scaffolds. OBJECTIVE:To verify the biocompatibility of chitosan-modified silk fibroin with human adipose-derived stem cells (hADSCs), and feasibility of constructing tissue engineered adipose in vitro. METHODS:The hADSCs at passage 3 were seeded on chitosan-modified silk fibroin at the concentration of 1×107/L, as the experiment group;at the same cellconcentration, hADSCs were seeded in 96-wel plates as the control group. MTT tests were performed to evaluate the adhesion, growth and proliferation of hADSCs on chitosan-modified silk fibroin. Then hADSCs were implanted on the chitosan-modified silk fibroin scaffolds at the concentration of 1×109/L. The hADSCs seeded onto chitosan-modified silk fibroin complexes were respectively cultured with adipogenic differentiation medium and ordinary high-glucose DMEM. The complexes were stained with oil red O, and detected with RT-PCR after cultured 14 days. RESULTS AND CONCLUSION:The hADSCs adhered to and proliferated on the scaffolds. After cultured with adipogenic differentiation medium for 14 days, oil red O staining demonstrated that there were amount of mature adipocytes on the scaffold. The peroxisome proliferator activated receptorγ2 was positively expressed. The chitosan-modified silk fibroin possessed excellent biocompatibility in vitro. The co-cultured hADSCs could be induced to mature adipocytes successful y.

BACKGROUND:Low toxicity of Genipin has certain species and cellspecificity. Biocompatibility of Genipin cross-linked type I colagen with human adipose-derived stem cels is essential for construction of
tissue-engineered adipose.
OBJECTIVE:To investigate the bbiocompatibility of Genipin cross-linked type I colagen with human adipose-derived stem cels.
METHODS:Human adipose-derived stem cels were isolated and cultured to the third generation, and the cels were seeded on Genipin cross-linked type I colagen scaffold. MTT assay was used to evaluate the adhesion and proliferation of cels on the scaffold, and the toxic effects of Genipin cross-linked type I colagen on human
adipose-derived stem cels. Optical microscopy and scanning electron microscopy were utilized to observe the adhesion and growth process of human adipose-derived stem cels on the scaffold as wel as the morphological changes of cels.
RESULTS AND CONCLUSION:Human adipose-derived stem cels could adhere to the scaffold immediately
after seeded and increase gradualy on the scaffold, with the average adhesion rate of 86.5%. Optical microscopy and scanning electron microscopy showed that human adipose-derived stem cels adhered wel on the scaffold. The cels increased gradualy over time, and could migrate into the scaffold, and distribute evenly with the passage of time when observed with optical microscopy. The result showed Genipin possesses very low cytotoxicity to the cels, and the outstanding biocompatibility is found between the cels and scaffoldin vitro after cross-linked with Genipin.

Staphylococcus epidermidis is the most important member of the coagulase-negative staphylococci and one of the most abundant colonizers of human skin.S.epidermidis is a bacterial species that is commonly described as relatively innoc-uous,which is in part due to the notion that it lacks secreted toxins with limited capability of infection.S.epidermidis pro-duces a series of molecules that provide protection from host defenses,including many proteins and exopolymers.Further-more,recent research has identified a family of cytolytic peptidesin S.epidermidis,the phenolsoluble modulins (PSMs),and the notion that S.epidermidis is virtually toxin-free had to be somewhat revised.

BACKGROUND:Many scholars researched the biomechanics of middle clavicle fracture plate fixation, but little researched the plate position. OBJECTIVE:To observe the biomechanical characteristics ofanterior and superior plates for clavicle fracture with three-dimensional finite element models. METHODS:Three-dimensional finite element models of clavicle fracture with anterior and superior plates were established. The stress after anterior and superior plate fixation was analyzed. The maximum stress and displacement of plate fixation for clavicular fracture were observed under compression, torsion and three-point bending. RESULTS AND CONCLUSION:(1) In the compressed condition, the maximum stressand maximum fracture displacement were similar between the superior and anterior plate fixation (P> 0.05). (2) Under clockwise twist condition, the maximum stress and maximum fracture displacement were smaler in the superior plate fixation group than inthe anterior plate fixation group (P< 0.05). (3) Under counterclockwise twist condition, the maximum stress and maximum fracture displacement were similar between the anterior and superior plate fixation groups (P> 0.05). (4) Under three-point bending condition, the maximum stress was similar between the superior and anterior plate fixation groups (P> 0.05). The maximum fracture displacement was bigger in the superior plate fixation group than in the anterior plate fixation group (P< 0.05). (5) These findings suggest that superior fixation of clavicle fracture reconstruction plate has more advantages than the anterior plate fixation.

Objective To introduce a novel femoral distractor which is applied in close reduction and internal fixation (CRIF) with antegrade intramedullary nail for femoral shaft fractures.Methods From September 2010 to March 2015,85 patients with femoral shaft fracture were treated by CRIF with antegrade intramedullary nail in which our self-designed novel distractor was used.They were 64 males and 21 females,with an average age of 36.6 years.By AO classification,we had 32 cases of type 32-A,40 cases of type 32-B,and 13 cases of type 32-C.The intervals between injury and surgery averaged 7.5 days (range,from 1 to 16 days).The fracture was located at the upper shaft in 26 cases,at the middle shaft in 57 cases,at the middle shaft and ipsilateral neck in one,and at the lower shaft and ipsilateral intertrochanteric site in one.Their operation time,intraoperative blood loss,intra-and post-operative complications,and fracture union time were recorded and analyzed.Results Successful close reduction was achieved in all the 85 patients with no iatrogenic injury to major vessels or nerves.Operation time averaged 105.5 minutes;time for X-ray exposure averaged 25.8 seconds;intraoperative blood loss averaged 209.2 mL.The 85 patients received follow-ups from 8 to 24 months (mean,16.3 months).Fracture union was achieved in 83 cases after an average duration of 7.8 weeks (range,from 4 to 12 weeks),but nonunion occurred in 2 cases.One-year follow-ups revealed recovery of normal function of the affected knee in all,with no limb shortening ＞ 10 mm,rotational angulation ＞ 15°,or lateral or anteroposterior angulation ＞ 10°.No incision infection,deep vein thrombosis or pulmonary embolism happened during the entire follow-up.Conclusion Our self-designed novel distractor can facilitate CRIF with antegrade intramedullary nail for femoral shaft fractures,and avoid the complications and inconvenience associated with a traction table.

We studied cutinase production from short-chain organic acids by Thermobifida fusca WSH03-11 to evaluate the possibility of converting municipal sludge to high value-added products. The optimum organic acid (8.0 g/L) and nitrogen source (1.5 g/L) concentrations were determined by the single factor experiments with butyric acid, propionic acid and acetic acid as the carbon sources. When lactic acid was used as the carbon source, the optimum organic acid (3.0 g/L) and nitrogen source (1.0 g/L) concentrations were obtained. Cutinase production by T. fusca WSH03-11 was further improved with butyric acid (by 31.0%), propionic acid (by 13.3%), acetic acid (by 43.8%) and lactic acid (by 73.2%) as carbon source, respectively, with the optimized cutin concentrations. Among these four short-chain organic acids, the average specific consumption rate of acetic acid was the highest, higher than that of propionic acid 1.3-folds, butyric acid 2.0-folds and lactic acid 2.2-folds. The highest cutinase activity reached 52.4 u/mL with butyric acid (8 g/L) as the sole carbon source, higher than that of lactic acid (3 g/L) 1.7-folds, acetic acid (8 g/L) 2.5-folds and propionic acid (8 g/L) 3.2-folds. The yield of cutinase activity on lactic acid (12.70 u/mg) higher than that of butyric acid 1.4-folds, propionic acid 3.0-folds and acetic acid 3.8-folds. T. fusca WSH03-11 consumed acetic acid firstly in mixed acids carbon sources, and the consumption of butyric acid was inhibited. Further studies indicated that the consumption rate of butyrate was decreased by 66.7% in the presence of 0.5 g/L acetic acid in the mixed acids. This was the first report concerning the production of cutinase by T. fusca with mixed organic acids as the carbon sources. The results presented here provided a novel and efficient approach to produce high value-add products from municipal sludge, and also established a foundation for the industrial production of cutinase by T. fusca WSH03-11 with cheap carbon sources from the processing of municipal sludge.
Acetates ; metabolism ; Actinomycetales ; growth & development ; metabolism ; Butyric Acid ; metabolism ; Carboxylic Ester Hydrolases ; biosynthesis ; Fermentation ; Organic Chemicals ; metabolism ; Propionates ; metabolism

Objective To investigate the effect of periosteum deficiency on the treatment of segmental bone defect of lower extremity by Ilizarov bone transport Technique.Methods From April 2009 to April 2016,data of 54 cases with lower limb segmental bone defect who were treated by Ilizarov bone transport technique were retrospectively analyzed.According to intraoperative observation of the distribution of periosteum at the osteotomy site,all cases were divided into two groups.There were 10 cases in absent periosteum group,including 6 males and 4 females,aged from 23 to 57 years old (mean,38.20±9.90 years old).There were 3 cases locating at femur,and 7 cases at tibia.4 cases had non-infective bone defect,while the other 6 had infective bone defect.Segmental bone defect ranged from 4.0 to 14.0 cm (mean,6.85±2.87 cm).There were 44 cases in normal periosteum group,including 32 males and 12 females,aged from 22 to 65 years old (mean,38.90±10.10 years old).There were 9 cases locating at femur and 35 cases at tibia.12 cases had non-infective bone defect,while 32 cases had infective bone defect.Segmental bone defect ranged from 4.0 to 9.0 cm (mean,6.09±1.54 cm).Visual analogue scale (VAS) was used to estimate the pain during bone transport.The distraction index,bone healing index,external fixator index was collected to evaluate the distraction osteogenesis and mineralization.The Paley method was utilized to appraisal the function of proximal joints in bone transport.Results All the 54 cases were followed up for 24-48 months,with an average of 28.50±5.70 months.All skin and soft tissue defects were satisfied healed.All limbs were restored to their original lengths,and bone healing was eventually achieved.There were no statistically significant differences in the distraction index,bone healing index,external fixator index,VAS between absent periosteum group (12.29± 1.04 d/cm,39.00±3.96 d/cm,51.25±3.69 d/cm,3.30± 1.77 score) and normal periosteum group (11.67±0.96 d/cm,38.07±4.22 d/cm,49.74±4.25 d/cm,3.36± 1.66 score)(P ＞ 0.05).Paley adjacent joint function evaluation showed no statistically difference between absent periosteum group [good rate 100％(10/10)] and normal periosteum group [good rate 97.7％ (43/44)] (P=0.901).The overall incidence of complications was 20.0％ (2/10) in the absence of periosteum group,with 1 case of mild infection and 1 cases of tissue contracture incarcerated at the docking site.The overall incidence of complications was 27.3％ (12/44) in the normal of periosteum group,with 2 cases of mild infection,3 cases of poor limb strength alignment,6 cases of tissue contracture incarcerated at the docking site and 1 case of severe foot drop deformity.There was no statistically significant difference in the overall incidence of complications between the two groups (P=0.636).Conclusion The absence of periosteum at the epiphyseal osteotomy site hasno significant effect on Ilizarov bone transport technique in the treatment of segmental bone defects of lower limbs in bone regeneration and healing,mineralization and bone remodeling,and does not increase the incidence of complications.

Objective:To investigate the efficacy of treatment of Sanders Ⅱ & Ⅲ calcaneal fractures with an absorbable stick plus Kirschner wire through the tarsal sinus incision.Methods:From July 2017 to May 2020, 37 patients with 42 Sanders Ⅱ & Ⅲ calcaneal fractures were treated with an absorbable stick plus Kirschner wire through the tarsal sinus incision at The Third Ward of Department of Traumatic Orthopeadics, The Sixth Hospital of Ningbo. There were 25 males and 12 females, with an age of (48.2±5.6) years (from 20 to 69 years). The fractures were at the left side in 12 cases, at the right side in 20 and at bilateral sides in 5. By Sanders classification, 20 fractures were type Ⅱ and 22 ones type Ⅲ. Fracture union time and complications were recorded. Their B?hler and Gissane angles were compared between preoperation, postoperation and the last follow-up. The range of motion of the subtalar joint was evaluated by the Morrey method at 6 months postoperation. The functional recovery was evaluated by the American Society of Foot and Ankle Surgery (AOFAS) ankle-hindfoot score at 12 months postoperation.Results:The 37 patients were followed up for (15.2±2.7) months (from 13 to 18 months). There were no such complications as incision skin necrosis, Kirschner wire deformation, loss of fracture reduction or Kirschner wire infection. The anatomical morphology of the calcaneus was restored satisfactorily in the 37 patients. At preoperation, postoperation and the last follow-up, the B?hler angles were 13.3°±1.6°, 32.5°±5.5° and 32.7°±5.4° and the Gissane angles 78.3°±6.7°, 127.2°±6.7° and 128.0°±6.4°, respectively, showing significant differences between the preoperative and postoperative values ( P<0.05) but no significant differences between postoperation and the last follow-up ( P>0.05). The range of motion of the subtalar joint at 6 months postoperation was slightly limited in 25 cases and moderately limited in 12 cases, giving a rate of moderate and above limitation of 32.4% (12/37). By the AOFAS ankle-hindfoot score at 12 months postoperation, 12 cases were excellent, 21 ones good and 4 ones fair, giving a good to excellent rate of 89.2% (33/37). Conclusion:Treatment with an absorbable stick plus Kirschner wire through the tarsal sinus incision may lead to fine clinical efficacy for Sanders Ⅱ & Ⅲ calcaneal fractures.

Objective:To evaluate the efficacy and safety of total aortic arch replacement in elderly patients with Stanford type A aortic dissection(TAAD).Methods:In this retrospective study, a total of 481 TAAD patients treated with total arch replacement in our hospital from January 2016 to January 2020 were divided into three groups: aged≤59 years, 60-69 years and ≥70 years.The differences between three groups in surgical method, extracorporeal circulation time, blocking time, circulatory time, stopping time, surgical time, ventilator use time, ICU time, hospitalization time, treatment rate of continued renal replacement, fatality rate, and cause of death were statistically analyzed and compared.Results:There were statistically significant differences in the stopping time between any two groups of the three groups(all P<0.05). The older the age, the shorter the circulatory arrest time.The difference of ventilator time and ICU time between ≤59 and 60-69 years was statistically significant( P<0.01). Patients with continuous renal replacement(CRRT)were 19.0%(71/373)in ≤59 years, 23.1%(18/78)in 60~69 years, and 26.7%(8/30)over 70 years.In-hospital mortality was 35/373(9.4%)in the group of ≤59 years old, 11/78(14.1%)in the group of 60~69 years old, and 5/30(16.7%)in the group of ≥70 years old.There was no death in patients undergoing type Ⅱ hybrid surgery. Conclusions:Age is one of the important death factors after total aortic arch replacement in TAAD patients.Total aortic arch replacement is an acceptable surgical method for elderly patients with TAAD.Hybridization may reduce hospitalization death in elderly patients.