Bioinspired, Anticoagulative, 19 F MRI-Visualizable Bilayer Hydrogel Tubes as High Patency Small-Diameter Vascular Grafts.

The clinical patency of small-diameter vascular grafts (SDVGs) (ID < 6 mm) is limited, with the formation of mural thrombi being a major threat of this limitation. Herein, a bilayered hydrogel tube based on the essential structure of native blood vessels is developed by optimizing the relation between vascular functions and the molecular structure of hydrogels. The inner layer of the SDVGs comprises a zwitterionic fluorinated hydrogel, avoiding the formation of thromboinflammation-induced mural thrombi. Furthermore, the position and morphology of the SDVGs can be visualized via 19 F/1 H magnetic resonance imaging. The outer poly(N-acryloyl glycinamide) hydrogel layer of SDVGs provides matched mechanical properties with native blood vessels through the multiple and controllable intermolecular hydrogen-bond interactions, which can withstand the accelerated fatigue test under pulsatile radial pressure for 380 million cycles (equal to a service life of 10 years in vivo). Consequently, the SDVGs exhibit higher patency (100%) and more stable morphology following porcine carotid artery transplantation for 9 months and rabbit carotid artery transplantation for 3 months. Therefore, such a bioinspired, antithrombotic, and visualizable SDVG presents a promising design approach for long-term patency products and great potential of helping patients with cardiovascular diseases.

Safety and Effectiveness of Diode Laser Used in Stapes Surgery.

Objective: We comprehensively assessed the safety and effectiveness of a 980-nm diode laser with fiberoptic delivery in stapes surgery by laser energy use, complications, and audiometric outcomes. Materials and methods: We retrospectively reviewed 116 primary stapes surgery cases. A high-power (30-40 W), short-pulse (60 msec), 980-nm diode laser was used for superstructure removal and footplate fenestration in the diode laser group (DLG) and, the hook and drill method in the conventional technique group (CTG). Data on complications and surgical diode laser use were collected; audiometric results within 6 months postoperatively were included in the analysis. Results: In DLG, the median fenestration and superstructure resection energy were 4.80 and 18.23 J, respectively. Footplate floating occurred in two ears (2/128, 1.56%) with manual fenestration, although none in the DLG (p = 0.07). Six CTG patients (6/26, 23.08%) underwent inevitable stapedectomy owing to footplate dislocation, which was higher than that in the DLG (2.11%, p < 0.01). No patients in the DLG experienced sensorineural hearing loss, and bone conduction (BC) improved at 1 (preoperative and postoperative means: 23.69 and 20.93 dB, respectively; p = 0.003) and 2 kHz (preoperative and postoperative means: 35.28 and 31.40 dB, respectively; p < 0.001), whereas changes in BC at 0.5 and 3 kHz were stable (p > 0.05). Four DLG patients (4/107, 3.74%) experienced transient facial nerve palsy postoperatively. Laser energy analysis showed shorter superstructure vaporization intervals in patients with transient facial nerve palsy (mean, 11.65 sec; median of control, 24.57 sec; p = 0.037). Conclusions: High-power, short-pulse, 980-nm diode laser is safe and effective in stapes surgery.

Analysis of the clinical and genetic characteristics of a Chinese family with osteogenesis imperfecta type I.

BACKGROUND: Osteogenesis imperfecta type I (OI-I) is a rare genetic disorder characterized by skeletal deformity, bone fragility, blue sclerae, dentinogenesis imperfecta, and hearing loss. The current study aimed to confirm the clinical diagnosis and genetic cause of OI-I in a four-generation Chinese family. METHODS: Clinical investigation and pedigree analysis were conducted to characterize the phenotypic manifestations of a Chinese family with OI-I. Follow-up audiometry and imaging tests were used to evaluate the postoperative outcomes of stapes surgery in the proband with otosclerosis. Whole-exome sequencing (WES) and Sanger sequencing were used to identify the pathogenic gene variants and for cosegregating analysis. RESULTS: We described in detail the clinical features of the collected family with autosomal dominant OI-I, and firstly identified a pathogenic splicing variant (c.2344-1G>T) in intron 33 of COL1A1 in a Chinese family. The molecular analysis suggested that the mutation might cause splice site changes that result in a loss of gene function. The proband, who suffered from otosclerosis and presented two-side middle-severe conductive hearing loss, benefitted significantly from successive bilateral middle ear surgery. CONCLUSIONS: The diagnosis of OI-I in a Chinese family was established by clinical and genetic investigation. A heterozygous pathogenic splicing variant in COL1A1 was directly responsible for the bone fragility and hearing loss of this family. Otosclerosis surgery should be suggested to rehabilitate conductive hearing impairment in OI patients.

[Value of cone-beam computer tomography in the middle and inner ear observation].

Objective:To identified the feasibility and normal range of cone beam computer tomography（CBCT） in the measurement of temporal bone. Methods:15 formalin fixed human cadaver head specimens were scanned by CBCT, high resolution CT, and Micro CT, respectively. Morphological parameter measurements of the middle and inner ear structures including ossicular chain, cochlea, semicircular canal and facial nerve were performed, and the results measured by the three scanning methods were compared. Results:None of the parameters measured by the three scanning methods were statistically significant except the thickness of stapes footplate（P<0.01） and the diameter of cochlear basal turn（P<0.01）. CBCT was superior in detecting facial nerve bony canal dehiscence. Conclusion:CBCT has the advantages of short scanning time, low radiation dose and high resolution. It can accurately display the morphological characteristics of the temporal bone structures, and is a reliable evaluation method for otological surgery.

Fluorescent DNA-templated silver nanoclusters for highly sensitive detection of D-penicillamine.

Herein, fluorescent DNA-templated silver nanoclusters (DNA-AgNCs) with red emission were synthesized and utilized as novel probe to detect D-penicillamine (D-Pen) for the first time. D-Pen molecules contain a thiol which can combine with Ag to form a non-fluorescent ground state complex, inducing the aggregation of DNA-AgNCs followed by the fluorescence quenching. The quenching mechanism is well-studied and found to be a static quenching process. This method can detect D-Pen in the range of 0.025-0.7 µM with the detection limit as low as 8 nM, which is 1-3 orders of magnitude more sensitive than those based on other fluorescent nanoprobes. More importantly, the preparation procedure for DNA-AgNCs is fast and without the requirement of heavy metal ions. Thus, this detection strategy is time-saving and eco-friendly. Satisfactory recoveries have been acquired for monitoring D-Pen in human serum samples and pharmaceutical samples owing to the high sensitivity.

A ratiometric fluorescence assay for bleomycin based on dual-emissive chameleon DNA-templated silver nanoclusters.

The authors design dual-emissive DNA-templated silver nanoclusters (DNA-AgNCs) for ratiometric fluorescence sensing bleomycin (BLM) for the first time. A hairpin probe containing two different C-rich DNA templates at two terminals is used to synthesize chameleon DNA-AgNCs, which possess two emission peaks when they are in close proximity. A strong emission is founded at 622 nm (λex = 570 nm) while a weak one is located at 572 nm (λex = 504 nm). Meanwhile, the loop of this probe contains the scission site (5'-GC-3') of BLM. The loop can be cleaved into two parts by BLM-Fe(II) complex, inducing the two DNA-AgNCs away from each other. The fluorescence intensity at 572 nm and 622 nm increases and decreases, respectively. Such chameleon DNA-AgNCs exhibit an obvious fluorescence discoloration from orange to yellow. Therefore, a sensitive ratiometric fluorescent strategy for BLM detection has been proposed with the detection limit of 67 pM. Finally, this ratiometric method is used to detect BLM in serum samples.

Colorimetric determination of the activities of tyrosinase and catalase via substrate-triggered decomposition of MnO2 nanosheets.

The authors describe novel colorimetric assays for tyrosinase (TYR) and catalase (CAT) based on the substrate-triggered decomposition of MnO2 nanosheets (NSs). The MnO2 NSs can act as oxidase mimics that catalyze the oxidation of the substrate tetramethylbenzidine (TMB) to form a blue dye with an absorption maximum at 652 nm. The oxidase-mimicking activity of the MnO2 NSs is inhibited by dopamine (DA)/hydrogen peroxide (H2O2) due to their decomposition of the MnO2 NSs. TYR catalyzes the oxidation of DA while CAT can decompose H2O2 into water and oxygen. Therefore, the oxidase-mimicking activity of MnO2 NSs is restored in the presence of both enzymes and their substrates. Based on the competitive consumption of substrates between enzymes and MnO2 NSs, a colorimetric method for determination of enzyme activity and its substrate is developed. The detection limits for TYR and CAT are 6 mU·mL-1 and 33 mU·mL-1, respectively. Graphical abstractA colorimetric method for monitoring enzyme activity and its substrate is described. It is based on the substrate-inhibited oxidase-mimicking activity of MnO2 nanosheets.