In cases where a tracheal injury exceeds half the length of the adult trachea or one-third of the length of the child trachea, it becomes difficult to perform end-to-end anastomosis after tracheal resection due to excessive tension at the anastomosis site. In such cases, tracheal replacement therapy is required. Advances in tissue engineering technology have led to the development of tissue engineering tracheal substitutes, which have promising applications. Hydrogels, which are highly hydrated and possess a good three-dimensional network structure, biocompatibility, low immunogenicity, biodegradability, and modifiability, have had wide applications in the field of tissue engineering. This article provides a review of the characteristics, advantages, disadvantages, and effects of various hydrogels commonly used in tissue engineering trachea in recent years. Additionally, the article discusses and offers prospects for the future application of hydrogels in the field of tissue engineering trachea.

BACKGROUND:For the replacement treatment of long-segment tracheal defects,although tissue engineering research has made some progress in recent years,it is still not perfect,and one of the biggest difficulties is that the hemodynamic reconstruction of the tracheal replacement cannot be achieved rapidly. OBJECTIVE:To preliminarily explore the potential of polycaprolactone scaffolds modified with exosome-loaded hydrogels to construct a rapidly vascularized tracheal substitute. METHODS:Exosomes were extracted from bone marrow mesenchymal stem cells of SD rats.After preparation of hyaluronic acid methacrylate solution,the exosome solution was mixed with hyaluronic acid methacrylate solution at a volume ratio of 1:1.Hyaluronic acid methacrylate hydrogels loaded with exosomes were prepared under ultraviolet irradiation for 5 minutes.The degradation of exosome-unloaded hydrogels and the controlled release of exosome-loaded hydrogels were detected.Polycaprolactone scaffolds were prepared by 3D printing.The pure hyaluronic acid methacrylate solution and the exosome-loaded hyaluronic acid methacrylate solution were respectively added to the surface of the scaffold.Hydrogel-modified scaffolds and exosome-modified scaffolds were obtained after ultraviolet irradiation.Thirty SD rats were randomly divided into three groups with 10 rats in each group and subcutaneously implanted with simple scaffolds,hydrogel-modified scaffolds and exosome-modified scaffolds,respectively.At 30 days after surgery,the scaffolds and surrounding tissues of each group were removed.Neovascularization was observed by hematoxylin-eosin staining and Masson staining and the expression of CD31 was detected by immunofluorescence. RESULTS AND CONCLUSION:(1)As time went by,the hydrogel degraded gradually,and the exosomes enclosed in the hydrogel were gradually released,which could be sustained for more than 30 days.The exosome release rate was faster than the degradation rate of the hydrogel itself,and nearly 20%of the exosomes were still not released after 30 days of soaking.(2)Under a scanning electron microscope,the surface of the simple polycaprolactone scaffold was rough.After hydrogel modification,a layer of gel was covered between the pores of the scaffold,and the scaffold surface became smooth and dense.(3)After 30 days of subcutaneous embedding,hematoxylin-eosin staining and Masson staining showed that more neovascularization was observed inside the scaffolds of the exosome-modified scaffold group compared with the hydrogel-modified scaffold group.The hydrogels on the scaffolds of the two groups were not completely degraded.Immunofluorescence staining showed that CD31 expression in the exosome-modified scaffold group was higher than that in the hydrogel-modified scaffold group(P<0.000 1).(4)These results indicate that hyaluronic acid methacrylate hydrogels can be used as controlled-release carriers for exosomes.The 3D-printed polycaprolactone scaffold modified by hyaluronic acid methacrylate hydrogel loaded with exosomes has good biocompatibility and has the potential to promote the formation of neovascularization.

Shear thinning is an ideal feature of bioink because it can reduce the chance of blocking. For extrusion based biological printing, bioink will experience shear force when passing through the biological printer. The shear rate will increase with the increase of extrusion rate, and the apparent viscosity of shear-thinning bioink will decrease, which makes it easier to block, thus achieving the structural fidelity of 3D printing tissue. The manufacturing of complex functional structures in tissue trachea requires the precise placement and coagulation of bioink layer by layer, and the shear-thinning bioink may well meet this requirement. This review focuses on the importance of mechanical properties, classification and preparation methods of shear-thinning bioink, and lists its current application status in 3D printing tissue trachea to discuss the more possibilities and prospects of this biological material in tissue trachea.

The treatment of patients with advanced lung cancer has been revolutionized with the advent of immunotherapy. However, not all patients can benefit equally from immunotherapy. In recent years, the relationship between intestinal flora and the efficacy of immunotherapy has gradually attracted scholars' attention. During the treatment of immune checkpoint inhibitors, the use of antibiotics, proton pump inhibitors and other drugs will affect the patient's intestinal flora, thus affecting the efficacy of immune checkpoint inhibitors, leading to poor prognosis of patients. This review will discuss that antibiotics and proton pump inhibitors reduce the efficacy of immunotherapy by affecting the diversity of intestinal flora, in order to facilitate the rational use of related drugs in clinical practice and improve the patient's outcomes.

Objective To analyze the current development of researches on biomarkers for predicting the efficacy of immunotherapy in non-small cell lung cancer and to provide reference for subsequent studies. Methods Studies on biomarkers for predicting the efficacy of immunotherapy for non-small cell lung cancer indexed in the Web of Science Core Collection from 2017 to 2021 were searched by computer. The annual distribution, journals, authors, countries, institutions, and keywords of studies were visualized and analyzed by CiteSpace. Results A total of 426 studies were collected, including 298 articles and 128 reviews. The average number of published studies was about 85, and increased year by year. PD-L1 expression, tumor mutational burden, tumor microenvironment and liquid biopsy were hot keywords in this field. Conclusion In the future, combination of biomarkers in the liquid biopsy and tumor microenvironment with radiomics analysis will be the research hotspot and frontier in this field for more accurate assessment with tumor-related signatures such as lymphocytic immune status and characteristics of tumor lesions in non-small cell lung cancer patients.

Objective To analyze the current research application status and hotspots of nanoparticles in the treatment of non-small cell lung cancer (NSCLC) and predict the future development trend. Methods The Web of Science database was searched for literatures on nanoparticles use in the treatment of NSCLC from inception to November 2022. CiteSpace, VOSviewer and literature measurement analysis online platform (https://bibliometric.com/) were used for the visual analysis of the number of documents, source journals, authors, organizations, countries and keywords. Results A total of 742 English literatures were included. The results showed that the number of published literatures increased year by year from 2011 and reached the peak in 2020. Researches on nanoparticles and NSCLC treatment were mainly concentrated in China, the United States, India and Japan. China is a major research country in this field, but it lacked cooperation with other countries and related institutions. Among numerous research institutions, the Chinese Academy of Sciences was the authoritative and backbone force in this research field, with the number of published literatures ranking first and the research achievements outstanding. The keyword analysis found that "poly lactic-co-glycolic acid nanoparticles (PLGA NPs)" and "photothermal therapy" had become the latest breakout words since 2018. Moreover, the occurrence frequency of related keywords such as "drug delivery" increased significantly, indicating that the application of PLGA NPs in photothermal therapy might be the current research hotspot and future development trend of NSCLC treatment. Conclusion Currently, the domestic research on the treatment of nanoparticles and NSCLC is in a leading position in the world. The organic combination of nanoparticles with different materials and other NSCLC therapies is expected to improve the prognosis of NSCLC patients. In the future, attempts to develop nanoparticles with different sources and structures and combined with photothermal therapy for the treatment of NSCLC may become a research hotspot of nanoparticles in the treatment of NSCLC.

Objective    To investigate the clinical effect of thoracoscopic lobectomy versus segmentectomy in the treatment of T1bN0M0 non-small cell lung cancer (NSCLC). Methods    Clinical data of 181 patients with T1bN0M0 NSCLC admitted to our hospital from 2012 to 2015 were retrospectively analyzed. They were divided into a lobectomy group and a segmentectomy group according to surgical methods. There were 117 patients in the lobectomy group (46 males and 71 females aged 61.32±8.94 years) and 64 patients in the segmentectomy group (20 males and 44 females aged 58.55±12.57 years). Perioperative indicators and prognosis were compared between the two groups. Results    The segmentectomy group had longer operation time, less intraoperative blood loss, shorter postoperative hospital stay and more preservation of lung function compared with the lobectomy group (P<0.05). The lobectomy group had higher consolidation tumor ratio, bigger tumor diameter, and more lymph node sampling compared with the segmentectomy group (P<0.05). There was no statistical difference in 5-year overall survival or recurrence-free survival between the two groups (P<0.05). Conclusion    For patients with T1bN0M0 NSCLC, thoracoscopic segmentectomy and lobectomy have similar prognosis, but segmentectomy has advantages with less injury and faster recovery over lobectomy.

Objective: To establish an experimental model of Turner′s tooth caused by trauma in SD rats and observe its surface by scanning electronic microscopes(SEM) and energy dispersive spectrometry(EDS) was performed. Methods: 40 SD rats aged one day were randomly divided into four groups(n=10). The control group did nothing, The experimental group was exerted different perpendicular forces(per 5 mm2) on the mandibular anterior alveolar process, which was divided into 5 N force group, 10 N force group and 15 N force group. The SD rats were killed at 30 days old to observe the enamel development of their mandibular central incisors. Meanwhile, SEM and EDS were used to observe normal enamel area and enamel hypoplasia area. Results: The control group: all teeth erupted; all enamels developed well. 5 N force group: all teeth erupted; the occurrence rate of enamel hypoplasia was 10%(2 teeth had enamel discoloration). 10 N force group: 1 tooth unerupted; the occurrence rate of enamel hypoplasia was 80%(12 teeth had enamel discoloration and 4 had enamel defects). 15 N force group: 7 teeth unerupted, the occurrence rate of enamel hypoplasia was 60%(3 teeth had enamel discoloration and 9 had enamel defects). There was a statistic difference in the number of unerupted teeth between group 10 N force group and 15 N force group(P<0.05). Under SEM, cracks and rough appeared on the surface of enamel. EDS showed that the Ca and P content in enamel hypoplasia was lower than that in the normal enamel area(P<0.05). Conclusion Tooth trauma can lead to enamel hypoplasia and unerupted teeth. The force of 10 N per 5 mm2is better to establish an experimental model of Turner′s tooth caused by trauma in SD rats. The surface enamel of Turner′s tooth caused by trauma is rough, uneven and the content of calcium and phosphorus decreases.

Objective:To establish a dental fluorosis model of SD rats with various degrees, to observe the microstructures of enamel samples under scanning electron microscope and to clarify the changes of enamel microstructures with various degrees of dental fluorosis, so as to provide clinical reference for the treatment of patients with moderate and severe dental fluorosis.Methods:Thirty male SD rats (6 weeks of age) were randomly divided into 3 groups with 10 rats in each group. The control group was fed with deionized water without fluoride, the low fluoride group was fed with 50 mg/L NaF deionized water and the high fluoride group was fed with 100 mg/L NaF deionized water in order to establish the dental fluorosis model of rats. After feeding for 6 weeks, the rats were sacrificed and the mandibular incisor teeth were collected and recorded. The surface and sagittal plane of each tooth were observed by scanning electron microscopy and the enamel thickness was measured.Results:In the control group, the enamel color was brown yellow. Enamel color discoloration occurred both in low-fluoride group and high-fluoride group. The enamel color in low-fluoride group was mostly yellow and white striped while in high-fluoride group was mostly chalky white. Under electronic microscope, the enamel rods were alternately arranged and their structure was clear and plump in the control group. The enamel rods of moderate fluorosis were arranged in a straight orientation like tips of bamboo shoots. The enamel rods of severe fluorosis, however, became thinner and the tips of rods were broken. In the control group, sagittal images of enamel turned out to be a dense outer structure with clear boundaries among the inner. The structure of the middle layer was reticulated showing a clear boundary with middle and outer layers. The structure of enamel rods in the inner layers was arranged vertically and horizontally. In the moderate fluorosis group, the outer layer of the enamel became thinner and the middle layer disappeared although the boundary between the outer and middle layers was still clear. In the inner layer, the vertically arranged enamel rods seemed still clear, however the horizontal enamel rods disappeared. In the severe fluorosis group, the outer layer could not be traced. The middle layer was exposed to the air and the inner enamel rods contracted. The inner layers of the enamel had gradually become thinner with the development of the dental fluorosis. The thicknesses of inner layers in control, moderate and the severe groups were (180.71 ±7.01), (157.10 ±11.04) and (121.10 ±12.56) μm respectively. As for the thicknesses of the full layers in the above mentioned three groups, the same trend was observed. The thicknesses, in order of the severity of dental fluorosis, were (241.54 ±7.76), (207.42 ±14.36) and (143.79 ±14.60) μm. Conclusions:With the development of dental fluorosis, the outer enamel layers became thinner or disappeared and the inner enamel layers became thinner or lost its normal structure as well. It is highly recommended that the resin penetration could be used for the proper treatment of moderate and severe dental fluorosis and the strong bleaching and the micro-grinding should be used cautiously.

The morbidity and mortality of lung cancer were the highest in malignant tumors. In recent years, with the update of clinical assistant examination technology and the popularization of physical examination, especially the development of CT examination, more and more lung cancer in early stage are found in the form of pulmonary nodules. Surgery treatment should be considering as the first choice for early lung cancer. At present, various 3D technologies have been widely used in the field of medicine, leading the thoracic surgery to the direction of minimal invasion and precision. This review focuses on the current application of 3D technology in the perioperative period of early lung cancer.