Waardenburg syndrome is a rare genetic disease of auditory pigmentation. The main symptom is sensorineural hearing loss. Pigment disorders and other developmental defects in skin, hair, iris, fundus and other parts are specifically divided into four different subtypes, each of which corresponds to different pathogenic genes, which encode transcription factors and signaling molecules that play a key role in the development process of neural crest cells into melanocytes. Because there are multiple subtypes of Waardenburg syndrome, different subtypes exhibit different symptoms, signs and ocular manifestations. Patients with Waardenburg syndrome are often first treated in ENT head and neck surgery due to hearing loss. Lack of theoretical knowledge related to Waardenburg syndrome by ophthalmologists may lead to misdiagnosis or missed diagnosis. Although there are currently limited treatments for the disease, with the continuous development of gene therapy and hearing management methods, the future treatment prospects will be broader.
The rutile structure titanium oxide (Ti-O) film was prepared on the pure titanium material TA2 (99.999%) surface by the magnetic filter high vacuum arc deposition sputtering source. The method can not only maintain the material mechanical properties, but also improve the surface properties for better biocompatibility to accommodate the physiological environment. The preparation process of the Ti-O film was as follows. Firstly, argon ions sputtered to the TA2 substrate surface to remove the excess impurities. Secondly, a metal ion source generated Ti ions and oxygen ions by the RF discharge. Meanwhile a certain negative bias was imposed on the sample. There a certain composition of Ti-O film was obtained under a certain pressure of oxygen in the vacuum chamber. Finally, X-ray diffraction was used to research the structure and composition of the film. The results showed that the Ti-O film of the rutile crystal structure was formed under the 0.18 Pa oxygen partial pressure. A Nano scratch experiment was used to test the coating adhesion property, which demonstrated that the film was stable and durable. The contact angle experiment and the platelet clotting experiment proved that the modified surface method had improved platelet adhesion performance, and, therefore, the material possessed better biocompatibility. On the whole, the evaluations proved the modified material had excellent performance.
Three-dimensional (3D) printing is a low-cost, high-efficiency production method, which can reduce the current cost and increase the profitability of skin repair material industry nowadays, and develop products with better performance. The 3D printing technology commonly used in the preparation of skin repair materials includes fused deposition molding technology and 3D bioprinting technology. Fused deposition molding technology has the advantages of simple and light equipment, but insufficient material selection. 3D bioprinting technology has more materials to choose from, but the equipment is cumbersome and expensive. In recent years, research on both technologies has focused on the development and application of materials. This article details the principles of fused deposition modeling and 3D bioprinting, research advances in wound dressings and tissue engineering skin production, and future developments in 3D printing on skin tissue repair, including cosmetic restoration and biomimetic tissue engineering. Also, this review prospects the development of 3D printing technology in skin tissue repairment.
Research on the deposition of inhaled particles in human pulmonary acinus region is important to the pathogenesis investigation, prevention and treatment of lung diseases. Most of the current research focus on the final deposition fraction of inhaled particles in human acinar region, but little is involved in their dynamic deposition characteristics. In this paper, five multi-alveolar models, G3−G7, were built. The evaluation parameter 1/4 deposition time was introduced to study the particle deposition speed. The deposition characteristics of particles in the diameter ranging 0.1−5 μm were numerically simulated and summarized under the influence of factors such as the generation and structure of model, particle diameter and respiratory mode, shedding some new light on the further research of transport of inhaled particles. The results showed that the generation and structure of model had a significance effect on the deposition of particles. 0.1 μm particles were dominated by Brownian diffusion, which experienced a high deposition fraction, a fast deposition speed and a logarithmic deposition curve, while 5 μm particles were dominated by gravitational sedimentation, with a high deposition fraction, a fast deposition speed and an S-shaped deposition curve. The deposition of 0.3−1 μm particles were influenced greatly by convention and varied with the change of respiratory mode. The research methods and results in this paper can provide theoretical basis and data support for the further exploration of the mechanism, prevention and treatment of lung diseases.
【Abstract】 Objective The present study employed both static and dynamic imaging modal ities to study bothintra- and extravascular events attributing to steroid-associated osteonecrosis (ON) using an experimental protocol with a single low-dose l i ppolysaccharide (LPS) injection and subsequently three injections of high-dose methylprednisolone (MPS). Methods Fourteen 28-week-old male New Zealand white rabbits received one intravenous injection of LPS (10 μg/ kg). After 24 hours, three injections of 20 mg/kg of MPS were given intramuscularly at a time interval of 24 hours. Additional 6 rabbits were used as controls. Dynamic MRI was performed on bilateral femora for local intraosseous perfusion before and after LPS injection. Blood samples were collected for haematological examinations before and after LPS injection. Bilateral femora were dissected and decalcified for microCT-based microangiography. ON lesion, intravascular thrombus and extravascular marrow fat cell size were examined histopathologically. Results Intravascular thrombus was observed in all ON rabbits. Extravascular marrow fat cell size was significantly increased in ON rabbits than that of the controls (P lt; 0.05). Compared to basel ine, a significant decrease in ratio of tissue-type-plasminogen-activator/plasminogen-activator inhibitor 1,activated-partial- thromboplatin-time, and a significant increase in ratio of low-density-l ipoprotein/high-density-l ipoprotein were only found in ON rabbits (P lt; 0.05). Dynamic MRI showed a significant decrease in the perfusion index ‘maximum enhancement’ in the ON rabbits (P lt; 0.05) and microCT-based microangiography showed blocked stem vessels in ON samples.Overall, 93% of the rabbits (13/14) developed ON and no rabbits died throughout the experiment period. Conclusion Bothintra- and extravascular events were found attributing to the steroid- associated ON based on our experimental protocol with a single low-dose LPS injection and subsequent three injections of high-dose MPS. Both high ON incidence and no mortal ity in rabbits treated with this inductive protocol suggested its effectiveness for future studies on evaluation of therapeutic efficacy of interventions developed for prevention of steroid-associated ON.
The inhalation and deposition of particles in human pulmonary acinus region can cause lung diseases. Numerical simulation of the deposition of inhaled particles in the pulmonary acinus region has offered an effective gateway to the prevention and clinical treatment of these diseases. Based on some important affecting factors such as pulmonary acinar models, model motion, breathing patterns, particulate characteristics, lung diseases and ages, the present research results of numerical simulation in human pulmonary acinus region were summarized and analyzed, and the future development directions were put forward in this paper, providing new insights into the further research and application of the numerical simulation in the pulmonary acinus region.
ObjectiveTo manufacture a polycaprolactone (PCL)/type Ⅰ collagen (COL Ⅰ) tissue engineered meniscus scaffold (hereinafter referred to as PCL/COL Ⅰ meniscus scaffold) by three-dimensional (3D) printing with low temperature deposition technique and to study its physicochemical properties.MethodsFirst, the 15% PCL/4% COLⅠ composite solution and 15% PCL simple solution were prepared. Then, 15% PCL/4% COL Ⅰmeniscus scaffold and 15% PCL meniscal scaffold were prepared by using 3D printing with low temperature deposition techniques. The morphology and microstructure of the scaffolds were observed by gross observation and scanning electron microscope. The compression modulus and tensile modulus of the scaffolds were measured by biomechanical test. The components of the scaffolds were analyzed by Fourier transform infrared spectroscopy (FTIR). The contact angle of the scaffold surface was measured. The meniscus cells of rabbits were cultured with the two scaffold extracts and scaffolds, respectively. After cultured, the cell proliferations were detected by cell counting kit 8 (CCK-8), and the normal cultured cells were used as controls. Cell adhesion and growth of scaffold-cell complex were observed by scanning electron microscope.ResultsAccording to the gross and scanning electron microscope observations, two scaffolds had orientated 3D microstructures and pores, but the surface of the PCL/COLⅠ meniscus scaffold was rougher than the PCL meniscus scaffold. Biomechanical analysis showed that the tensile modulus and compression modulus of the PCL/COL Ⅰ meniscus scaffold were not significantly different from those of the PCL meniscus scaffold (P>0.05). FTIR analysis results showed that COL Ⅰ and PCL were successful mixed in PCL/ COL Ⅰ meniscus scaffolds. The contact angle of PCL/COLⅠ meniscus scaffold [(83.19±7.49)°] was significantly lower than that of PCL meniscus scaffold [(111.13±5.70)°] (t=6.638, P=0.000). The results of the CCK-8 assay indicated that with time, the number of cells cultured in two scaffold extracts showed an increasing trend, and there was no significant difference when compared with the control group (P>0.05). Scanning electron microscope observation showed that the cells attached on the PCL/ COL Ⅰ meniscus scaffold more than that on the PCL scaffold.ConclusionPCL/COLⅠmeniscus scaffolds are prepared by 3D printing with low temperature deposition technique, which has excellent physicochemical properties without cytotoxicity. PCL/COLⅠmeniscus scaffold is expected to be used as the material for meniscus tissue engineering.
Objective To investigate the influence of airflow limitation upon lung deposition of inhaled corticosteroids in patients with chronic obstructive pulmonary disease ( COPD) . Methods The radionuclide 99mTc was used to lable budesonide which was inhaled through compressor nebulizer. Lung deposition was evaluated by nuclear medicine pulmonary ventilation scintigraphy. Peripheral to central ratio of lung deposition ( P/C% ) was calculated by region of interest ( ROI) metod. Results Forty-threepatients with stable COPD were enrolled in the study, of whom 41 patients completed the trial. The median age was 68 years ( range, 48 to 79 years) and the median FEV1 was 44. 9% predicted. The P/C% was ( 47. 96 ±6. 08) % . The patients with P/C% more than 50% had a higher FEV1% pred and FEV1 /FVC than those with P/C% less than 50% [ FEV1% pred: ( 51. 85 ±18. 20) % vs. ( 40. 52 ±12. 99) % .FEV1 /FVC: ( 59. 95 ±11. 87) % vs. ( 51. 73 ±9. 28) % ] . There was a positive correlation between P/C% and FEV1% pred ( r = 0. 391, P = 0. 024) and FEV1 /FVC ratio ( r = 0. 517, P = 0. 002) . Conclusion Lung peripheral airway deposition of inhaled corticosteroids was limited by airflow obstruction.
Inhalable particles deposition in the human respiratory system is the main cause of many respiratory and cardiovascular diseases. It plays an important role in related disease prevention and treatment through establishing computer or external entity models to study rules of particle deposition. The paper summarized and analyzed the present research results of various inhalable particle deposition models of upper respiratory tract and pulmonary area, and expounded the application in the areas of disease inducement analysis, drug inhale treatment etc. Based on the review, the paper puts forward the problems and application limitations of present research, especially pointing out future emphasis in development directions. It will have a value of reference guidance for further systematic and in-depth study on the inhalable particle deposition simulation, experiment and application.
Objective To investigate the construction of a novel tissue engineered meniscus scaffold based on low temperature deposition three-dimenisonal (3D) printing technology and evaluate its biocompatibility. Methods The fresh pig meniscus was decellularized by improved physicochemical method to obtain decellularized meniscus matrix homogenate. Gross observation, HE staining, and DAPI staining were used to observe the decellularization effect. Toluidine blue staining, safranin O staining, and sirius red staining were used to evaluate the retention of mucopolysaccharide and collagen. Then, the decellularized meniscus matrix bioink was prepared, and the new tissue engineered meniscus scaffold was prepared by low temperature deposition 3D printing technology. Scanning electron microscopy was used to observe the microstructure. After co-culture with adipose-derived stem cells, the cell compatibility of the scaffolds was observed by cell counting kit 8 (CCK-8), and the cell activity and morphology were observed by dead/live cell staining and cytoskeleton staining. The inflammatory cell infiltration and degradation of the scaffolds were evaluated by subcutaneous experiment in rats. Results The decellularized meniscus matrix homogenate appeared as a transparent gel. DAPI and histological staining showed that the immunogenic nucleic acids were effectively removed and the active components of mucopolysaccharide and collagen were remained. The new tissue engineered meniscus scaffolds was constructed by low temperature deposition 3D printing technology and it had macroporous-microporous microstructures under scanning electron microscopy. CCK-8 test showed that the scaffolds had good cell compatibility. Dead/live cell staining showed that the scaffold could effectively maintain cell viability (>90%). Cytoskeleton staining showed that the scaffolds were benefit for cell adhesion and spreading. After 1 week of subcutaneous implantation of the scaffolds in rats, there was a mild inflammatory response, but no significant inflammatory response was observed after 3 weeks, and the scaffolds gradually degraded. Conclusion The novel tissue engineered meniscus scaffold constructed by low temperature deposition 3D printing technology has a graded macroporous-microporous microstructure and good cytocompatibility, which is conducive to cell adhesion and growth, laying the foundation for the in vivo research of tissue engineered meniscus scaffolds in the next step.