Based on the self-assembly process occurring in the human body all the time, self-assembled nanomaterials were designed by the researchers. The self-assembled nanomaterials have controllability, biocompatibility and functional advantages in vivo. The self-assembled nanomaterials constructed in situ under a physiological environment display various biological characteristics which can be used for imaging, therapy, and broad clinical applications. In situ self-assembled nanomaterials can boost drug function, reduce toxic and side effects, prolong imaging time and enlarge signal-to-noise ratio. By using pathological conditions to trigger specific responses in vivo, well-ordered nanoaggregates can be spontaneously formed by multiple weak bonding interactions. The assembly shows higher accumulation and longer retention in situ. Endogenous triggers for in situ assembly, such as enzymes, pH, reactive oxygen species and ligand receptor interaction, can be used to transform the materials into a variety of controllable nanostructures including nanoparticles, nanofibers and gels through bioactivated in vivo assembly (BIVA) strategies. BIVA strategies can be applied for treatment, imaging or participate in the physiological activities of cells at the lesion site. This review summarized and prospected the design of self-assembled peptide materials based on BIVA technology and their biomedical applications. The nanostructures of the self-assembly enable some beneficial biological effects, such as assembly induced retention (AIR) effect, enhanced targeting effect, multivalent bond effect, and membrane disturbance. Thus, the BIVA nanotechnology is promising for efficient drug delivery, enhancement of targeting and treatment, as well as optimization of the biological distribution of drugs.
Drug Delivery Systems ; Humans ; Nanofibers/chemistry* ; Nanoparticles ; Nanostructures/chemistry* ; Peptides

Objective:To evaluate the clinical efficacy of the bridge pedicled transplantation of medial leg fascial flap combined with medial hemisoleus muscle flap for contralateral leg soft tissue defect.Methods:Between January of 2012 and January of 2018, 12 patients with soft tissue defect of the leg were treated with bridge pedicled transplantation of contralateral medial leg fascial flap combined with medial hemisoleus muscle flap by posterior tibial artery. There were 9 males and 3 female, aged from 19 to 53 years (mean, 35 years). The size of the soft-tissue defects ranged from 12 cm×8 cm to 18 cm×9 cm. The immediate coverage of the fascial and muscle flaps and vessel pedicle were repaired by a meshed split-thickness skin graft. The donor site was closed directly. After the transplantation of the one pedicle and two flaps survived, vascular pedicle was cut off.Results:All the fascial and muscle flaps survived completely. No clinical vascular deficiency was found on the fascial and muscle flaps postoperatively. One case developed distal muscle flap small skin graft necrosis, and spontaneous healed after 2 weeks of dressing change. Follow-up period ranged from 2.5 to 4.5 years (mean 3.8 years). A good contour was confirmed both at the recipient and donor sites. Satisfactory clinical results were obtained in this series.Conclusion:This method is suitable for the treatment of soft tissue defects of the leg with only one major blood vessel, which reduces the damage to the donor site.

Objective:To evaluate the efficacy of the repairing anterior tibial adjacent double wounds by transposition with single-pedicle two flaps of the medial head of gastrocnemius.Methods:Between January of 2012 and January of 2018, 10 patients with the anterior tibial adjacent double wounds (7 males and 3 female, aged from 21 to 45 years) were treated by transposition with single-pedicle two flaps of the medial head of gastrocnemius. The size of the soft-tissue defects ranged from 2.0 cm×2.5 cm to 4.5 cm×4.0 cm. The medial head of the gastrocnemius was divided into two flaps with a single pedicle to repair two adjacent wounds of the anterior tibial. The muscle flaps were immediately covered by a meshed split-thickness skin graft, and the wound in donor site was closed directly.Results:All the muscle flaps survived completely. No clinical vascular deficiency was found on the muscle flaps postoperatively. Small wound dehiscence was developed in one patient and spontaneously healed 2 weeks after dressing change. Patients were followed up for 2.0 to 4.5 years. A good contour was confirmed at the recipient and donor sites. Satisfactory clinical results were obtained in this series.Conclusion:This method is suitable for the repair of two adjacent small wounds of the anterior tibial which can reduce the damage to the donor site.

Objective　To confirm the effect of the pandemic on the health seeking behavior of patients by analyzing the changes of onset to door time（ODT） of patients with acute ischemic stroke（AIS） before and after the pandemic of COVID-19.Methods　Consecutive cases of hospitalized patients with AIS who visited the University of Hong Kong-Shenzhen Hospital in the same time span and at different periods were collected，including 100 cases in the pre-pandemic group（pre-PG），64 cases in the post-pandemic group（post-PG），and 86 cases in the Spring Festival group（SFG-19） in 2019.The chi-square test or t-test were used to analyze changes of ODT；Patients whose ODT more than 12 hours in post-PG were followed up，and descriptive statistics were performed on the reasons for delay of arrival. Results　The ODT of the post-PG was significantly prolonged compared with the pre-PG ［（38.8±69.9） hours vs （17.9±26.7） hours，P<0.05］，and the SFG-19 ［（38.8±69.9） hours vs （20.0±27.6）hours，P<0.05］. The proportion of ODT within 4.5 hours （28.1% vs 44%，P<0.05），6 hours （31.2% vs 48%，P<0.05），and 24 hours （62.5% vs 79%，P<0.05） in the post-PG was significantly less than the pre-PG. The proportion of ODT within 4.5 hours （28.1% vs 44.2%，P<0.05） and 6 hours （31.2% vs 48.8%，P<0.05） in the post-PG was significantly less than the SFG-19，but there was no significant difference in 24 hours （62.5% vs 74.4%，P>0.05）. The follow-up questionnaire found that the main reason for the delay of ODT as below：fear of infection with the virus，lack of knowledge about stroke，and insufficient attention，accounting for 66%，40%，and 37% of the respondents，respectively. Conclusion　The pandemic of COVID-19 significantly delay the ODT of patients with AIS and adversely affect its treatment.

Objective:To compare the efficacy and safety of domestic 16-row and imported 8-row mobile CT in clinics.Methods:A total of 1469 patients accepted domestic 16-row mobile CT head scans (1604 times) from March 2017 to August 2018 in Bayi Brain Hospital Affiliated to 7 th Medical Center of General Hospital of People's Liberation Army and Langfang Aidebao Hospital; and 15510 patients accepted imported 8-row mobile CT head scans (24994 times) from January 2016 to August 2018 in Bayi Brain Hospital Affiliated to 7 th Medical Center of General Hospital of People's Liberation Army. All patients underwent horizontal plain and enhanced head scans, cerebral CT angiography (CTA), and helical 3D imaging; and the imaging quality, operating power consumption, computed tomography dose index volume (CTDIvol) and stability within scanning volume ranges under different scanning modes of the two CT scans were compared. Results:(1) Imaging quality: the horizontal scanning of domestic 16-row mobile CT could clearly display low-density tissues such as the eyeball, optic nerve, brain stem, sulcus and cerebral gyrus; the imaging quality of both CT scans in patients with traumatic subdural hematoma and ischemic stroke completely met the clinical diagnosis and treatment standards. (2) Operating power consumption: the per-hour operating power consumption of domestic 16-row mobile CT ([0.286±0.018] kW·h) was obviously lower than that of imported 8-row mobile CT ([0.485±0.028] kW·h). (3) Radiological hazard: the CTDIvol of the horizontal scanning volume range in domestic 16-row mobile CT ([36.270±0.281] mGy) was significantly lower than that in the imported 8-row mobile CT ([82.520±0.441] mGy, P<0.05); the CTDIvol of enhanced axis scan volume range in the domestic 16-row mobile CT ([36.270±0.335] mGy) was significantly lower than that in the imported 8-row mobile CT ([70.728±0.424] mGy, P<0.05); the CTDIvol in the volume of CTA imaging of domestic 16-row mobile CT ([20.600±0.087] mGy) was significantly lower than that in the imported 8-row mobile CT ([29.300±0.335] mGy, P<0.05). The domestic 16-row mobile CT was designed with shock absorbers and guides; domestic 16-row mobile CT had small load, a low center of gravity, and good stability as compared with imported 8-row mobile CT. Conclusion:In terms of head scanning applications, the imaging quality of domestic 16-row mobile CT and imported 8-row mobile CT is in full compliance with clinical diagnostic standards, but the energy consumption and radiation risk of domestic 16-row mobile CT is significantly lower than imported 8-row mobile CT, enjoying good stability as compared with imported 8-row mobile CT.

Objective To discuss the application of self-developed novel 16-slice mobile CT head scan.Methods A total of 391 patients were performed 16-slice mobile CT scan:145 were scanned in the emergency department,156 in the neurosurgical ICU,55 in the operated room,and 35 in the ambulance vehicle.Sixty-eight patients were with brain injury,122 were with cerebral hemorrhage,120 were with cerebral infarction,59 were with brain tumors,and 22 were with hemifacial spasm.Thirty-five patients were randomly selected from 391 patients and 8-slice mobile CT head scan was performed on them,which included 12 with brain injury,6 with cerebral hemorrhage,12 with cerebral infarction,3 with brain tumors and 2 with hemifacial spasm.The resolution,imaging quality,radiation doses,power consumption and performance stability of novel 16-slice mobile CT and 8-slice mobile CT head scan were compared.Results The resolution line pairs of brain tissues were 91 p/cm by 16-slice mobile CT and 71 p/cm by 8-slice mobile CT,respectively.The imaging quality of the two kinds of mobile CT head scans was high level to the clinic diagnostic criteria.The radiation dose of 16-slice mobile CT were 40.43 mGy,which decreased by 51.01％ as compared with that of 8-slice mobile CT (82.52 mGy).The personal power consumption of 16-silce mobile CT (0.29 kW· h) decreased by 38.30％ as compared with those of 8-layer mobile CT (0.47 kW· h).The 16-slice mobile CT kept regularly,while 8-slicer mobile CT stopped to work twice during clinical trial.Conclusion The 16-slice mobile CT scan has high resolution,fine imaging quality,low radiation dose,small power consumption and stable working performance.

Objective To explore the effect of R-spondin3 on the proliferation of neural stem cells (NSCs) and its mechanism in mice.Methods The mouse NSCs derived from the subventricular zone of E 14-15d CD 1 mice were confirmed by immunofluorescence assay.The NSCs after 3 passages of culture were chosen and randomly divided into 2 groups (V=1 mL).In the experimental group,0.8 μL of R-spondin3 with an initial concentration of 50 μg/mL was added (final concentration:40 ng/mL) while in the control group an equal amount of culture fluid was added.The proliferation of the cells in the 2 groups was detected by 5-Bromo-2-deoxy Uridine (BrdU) kits after the cells were treated by R-spondin3 for 6 hours.The protein expression of [β-catenin was measured by western blotting after the cells were treated by R-spondin3 for 4 and 8 hours.Results Under optical microscopy,the round and bright cells grew in culture medium and easily accumulated to become neurospheres.Immunofluorescence assay showed that over 90％ of the cells expressed Nestin and SOX2 and that some of them expressed NeuN or GFAP after induced differentiation.Brdu proliferation test showed that the proliferation rate of Brdu+/DAPI+ for the experimental group (1.56±0.03) was significantly higher than that for the control group (1.04±0.04) (P＜0.05).Western blotting showed that the expression levels of [β-catenin were increased at both 4h and 8h after treatment for the experimental group (1.09±0.10 and 1.20±0.13),significantly higher than those for the control group (0.56±0.05 and 0.83±0.04) (P＜0.05).Conclusions R-spondin3 can promote in vitro proliferation of NSCs in mice,which may be associated with activated Wnt/β-catenin signal pathways.

Objective To explore the association,consistency and complications prognostic value of thromboelastography and conventional coagulation tests in detecting coagulation function of antiplatelet after endovascular treatments in patients with acute ischemic stroke.Methods A retrospective cohort survey of 240 patients,admitted to our hospital from September 2012 to December 2017,was performed.All acute ischemic stroke patients accepted coagulation function monitoring 5 d after aspirin and clopidogrel and endovascular treatments by thromboelastography (R time,K time,α angle,maximum amplitude [MA]) and routine coagulation tests (prothrombin time [PT],activated partial thromboplastin time [APTT],fibrinogen [FIB],international normalized ratio [INR],blood platelet count).The association,consistency,and sensitivity,specificity,positive predictive value,negative predictive value of complications prognostic value of thromboelastography and conventional coagulation tests were analyzed.Results (1) R time and APTT,K time and APTT,α angle and FIB,and α angle and PLT were positively correlated;K time and FIB,R time and PLT,and α angle and APTT were negatively correlated.(2) R time and APTT (κ=0.266,P=0.000),K time and APTT (κ=0.134,P=0.024),and α angle and FIB (κ=0.162,P=0.007) had agreement in identifying hypercoagulability;R time and APTT (κ=0.211,P=0.001),K time and APTT (κ=0.198,P=0.002),and blood platelet count and K (κ=0.388,P=0.000),and α angle and PLT (κ=0.099,P=0.041) had agreement in identifying hypocoagulability.(3) The sensitivity of thromboelastography and routine coagulation tests in identifying early neurological deterioration was 17.65％ and 58.82％,and the sensitivity in identifying symptomatic hemorrhages by thromboelastography and routine coagulation tests was 73.68％ and 47.39％.Conclusions Some parameters has correlations in peroperative period,and has agreement in identifying hypercoagulability and hypocoagulability.Accordingly,routine coagulation tests might be superior in evaluating early neurological deterioration,and thromboelastography might be superior in evaluating symptomatic hemorrhages in patients with acute ischemic stroke.

Objective To investigate the effect of galangin on proliferation and apoptosis of glioma cells in vitro.Methods (1) The glioma cells U87 and U25 1were divided into blank control group,DMSO group,100,200,300 and 400 μmol/L galangin treatment groups.MTT was used to study the effects of drugs on the proliferation of U251 and U87 cells.(2) Hoechest staining was used to observe cell apoptosis in the presence of different concentrations of galangin (0,100 and 200 μmol/L).(3) Flow cytometry was employed to detect the apoptosis of U251 and U87 cells in the presence of different concentrations of galangin (1 00 and 200 μmol/L).(4) Western blotting was employed to detect the expressions of apoptosis-related protein 3-Catenin,B-cell lymphoma-2 (Bcl-2),Bcl-2 related protein gene (Bax),cleaved-caspase-3,cleaved-caspase-9 and poly (ADP-ribose) polymerase (PARP) in the presence of different concentrations of galangin.Results (1) The proliferation of U251 and U87 cells was obviously inhibited atter 100,200,300 and 400 μmol/L galangin treatments,and dose-effect relation was noted.The concentrations of galangin at half rate of inhibition (IC50) were 281,321,276 and 229 μmol/L in U251 cells,and 289.4,261.1,247.4 and 225.3 μ mol/L in the U87 cells after 100,200,300 and 400μmol/L galangin treatments for 24 h.(2) Under the action of galangin,corresponding increase in apoptosis rates of U251 and U87 cells was noted following the increase of galangin concentrations (0,100 and 200 μmol/L),with significant differences (P＜0.05).(3) The detection of cell apoptosis by flow cytometry found similar changes.(4) Western blotting results indicated that galangin at the concentration of 0,100 and 200 μmol/L could significantly decrease the expressions of apoptosis-related protein 3-Catenin and Bcl-2,and increase the Bax,cleaved-caspase-3 and cleaved-caspase-9,and cleaved-PARP expressions;significant differences were noted between each two concentrations (P＜0.05).Conclusion Galangin can inhibit proliferation of glioma cells U251 and U87,and induce mitochondrial pathway of apoptosis via Wnt/β-Catenin signaling.

OBJECTIVETo evaluate the efficacy and safety of mechanical thrombectomy with the Solitaire AB device in recanalization of patients with acute ischemic stroke of posterior circulation.

METHODSThe clinical data of 17 consecutive patients with acute ischemic stroke of posterior circulation, treated with the Solitaire AB device from August 2011 to August 2015 in Department of Neurosurgery, the Military General Hospital of Beijing People's Liberation Army, were extracted and then retrospectively analyzed. There were 12 male and 5 female patients with a median age of 60 years (ranging from 44 to 75 years). Among them, 8 cases occluded in basilar artery, 4 cases occluded in vertebral artery and 5 cases occluded in vertebral plus basilar artery. Recanalization rate as well as complications after treatment were analysized. Also, neurological functions of the patients before and after treatment, measured by National Institute of Health stroke scale (NIHSS) score, were compared via t test and the clinical outcomes were assessed by modified Rankin score (mRS) at 90 days after treatment.

RESULTSFifteen patients resulted in successfully recanalization, and 2 cases failed both of whose onset to sheath time were above 7.5 hours. The NIHSS score at 7 days was 11±10, which was significantly decreased compared to the admission NIHSS score 17±5 (t=2.949, P=0.009). No symptomatic intracranial hemorrhage case was found after thrombectomy. At 90 days, one patient died(mRS 6), one patient seriously disabled (mRS 5), two patients moderately seriously disabled (mRS 4), four patients resulted in moderate outcome (mRS 3) and the other 9 patients achieved good outcome (mRS 0 to 2). The dead and seriously disabled cases were both due to failure in recanalization. Two moderately seriously disabled cases were probably attributed to their severe admission condition (NIHSS >20) and prolonged time (onset to sheath time >6 hours).

CONCLUSIONMechanical thrombectomy with the Solitaire AB device contributes to a high rate of recanalization with a low probability of complication and improves functional outcome in patients with acute ischemic stroke of posterior circulation.

Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Stents ; Stroke ; surgery ; Thrombectomy ; Treatment Outcome