Preparation and evaluation of a silk fibroin-polycaprolactone biodegradable biomimetic tracheal scaffold.

In tracheal tissue engineering, the construction of tracheal scaffolds with adequate biodegradable mechanical capacity and biological functions that mimic the structure of a natural trachea is challenging. To explore the feasibility of preparing biomimetic degradable scaffolds with C-type cartilage rings and an inner tracheal wall of polycaprolactone and silk fibroin. A mold was made according to the diameter of a rabbit trachea, and a silk fibroin tube and polycaprolactone ring attached to the tube were obtained by solution casting. The ring was fixed to the tube at a specific spacing using electrostatic spinning technology to construct a biomimetic tracheal scaffold; its porous structure was observed by scanning electron microscopy, its degradation properties were determined by in vitro enzymatic hydrolysis and its mechanical properties were obtained by pressure testing. The composite scaffold was transplanted subcutaneously into a rabbit model, and the scaffold was taken at 1, 2, and 4 weeks after surgery for sectioning to observe pre-vascularization. The Medical Ethics Committee of Guangdong Provincial People's Hospital approved the study. The general view of the biomimetic scaffold: the polycaprolactone ring was fixed firmly on the outer wall of the silk fibroin tube; the two corresponded in size, and they fitted closely. The surface of the polycaprolactone ring was smooth and dense, while the surface of the silk fibroin tube could be seen as a uniform porous structure. Scanning electron microscopy showed that the surface and profile of the fibroin tube had a uniform pore size and distribution. The pores were connected to form a network. In vitro, enzymatic hydrolysis experiments confirmed that the fibroin was degraded easily, with most being degraded at the end of week 1. The degradation slowed at 2, 3, and 4 weeks, while the degradation of polycaprolactone was extremely slow. A compression test showed that the compressive resistance of the silk fibroin-polycaprolactone biomimetic scaffolds was much better than that of the rabbit trachea at close thickness. In the tissue staining experiments, as the material degraded, fibrous tissues and blood vessels grew to replace the material, allowing the scaffold to obtain a blood supply and better mechanical properties. A quantitative analysis of CD31 showed that the results for the vascularization of the scaffold were better at 4 weeks than at 2 weeks following subcutaneous grafting (P < .05). The results confirmed that it is feasible to prepare porous, degradable silk fibroin-polycaprolactone biomimetic scaffolds with good mechanical properties and epithelial biological functions by mold casting.

The implications of an integrated management model of prenatal diagnosis/postnatal treatment for premature infants with critical congenital heart disease-a case-control study.

Background: The high death rate and medical costs of critical congenital heart disease (CCHD) in preterm infants has resulted in significant burdens on both countries and individuals. It is unclear how this affects the mortality of the integrated management model of prenatal diagnosis/postnatal treatment. This study explored the effects of the delivery classification scale for fetal heart and postnatal infants' CCHD on prenatal and postnatal integrated treatment strategies to improve the effectiveness of disease management in CCHD. Methods: This study was a case-control study, which retrospectively analyzed the clinical data of 79 preterm infants (<37 weeks) who underwent prenatal diagnosis and postpartum treatment in Guangdong Provincial People' s Hospital (China) from June 2017 to June 2019. According to the diagnostic and exclusion criteria, the subjects were divided into prenatal and postpartum diagnostic groups. The clinical characteristics and survival outcomes of patients were collected and compared. The delivery classification scale was used for risk stratification and patient management. Results: Among the 79 patients included in this study, 48 (60.76%) were diagnosed prenatally, and 31 (39.24%) were diagnosed postpartum. The prenatal diagnosis group was born slightly earlier during the gestation period [35.00 (33.29-35.86) vs. 35.57 (34.14-36.71) weeks, P<0.05], and their mothers were older (33.23±5.22 vs. 30.43±6.37 years, P<0.05). The difference in the admission age between the groups was statistically significant [0 (0-5.5) vs. 7 (5-16) days, P<0.001]. The median survival time of the prenatal diagnosis group was higher than the postnatal diagnosis group [48 months (95% CI: 40.78-57.29) vs. 39 months (95% CI: 34.41-44.32), P<0.05]. The 3-year survival rates of the classes I, II, and III were 92.31% (12/13), 59.09% (13/22), and 38.46% (5/13), respectively. The survival of class I as denoted in the delivery classification scale was better than classes II or III (class I vs. II, P<0.05; class I vs. III, P<0.05). Unexpectedly, the hospitalisation costs were lower and total in-hospital days were shorter in the postnatal diagnosis group. Conclusions: The results indicated that the integrated management of a prenatal diagnosis/postnatal treatment approach in premature infants may be effective. Furthermore, the delivery classification scale has a particular prognostic value for CCHD. The authors anticipate that their management model will be able to contribute to the shift from a reactive monodisciplinary system to a proactive, multidisciplinary and dynamic management paradigm in premature infants with CCHD in the near future.

The high-risk factors of different severities of bronchopulmonary dysplasia (BPD) based on the national institute of child health and human development (NICHD) diagnosis criteria in 2018.

OBJECTIVE: To investigate the clinical characteristics of preterm infants with different severities of bronchopulmonary dysplasia (BPD) and disclose the high-risk factors of exacerbating BPD. METHODS: Collection of clinical data of 91 preterm infants admitted to the NICU and diagnosed with BPD, categorized in groups according to the disease severity: 41 mild cases,, 24 moderate cases, and 26 severe cases. Comparison and analysis of perinatal risk factors, treatment, complications and prognosis of the infants with different severity degrees. RESULTS: The severe group had a higher proportion of infants with congenital heart disease (CHD) higher than the moderate group (P < 0.05), and a higher ratio of pneumonia and mechanical ventilation (MV) ≥ seven days than the mild group (P < 0.05). The severe group also presented higher reintubation incidence than both the mild and moderate groups (P < 0.05). The groups presented different (P < 0.05) incidence rates of hemodynamically significant patent ductus arteriosus (hsPDA) . Ridit analysis suggested that the premature infants (PIs) with hsPDA, multiple microbial pulmonary infections, or Klebsiella pneumoniae pneumonia had more severe illness. CONCLUSION: CHD, hsPDA, MV ≥ seven days, reintubation, pneumonia, especially multiple microbial pulmonary infections, and Klebsiella pneumoniae pneumonia are correlated with the severity of BPD and can be used as BPD progression predictor.

The significance of an integrated management mode of prenatal diagnosis-postnatal treatment for critical congenital heart disease in newborns.

BACKGROUND: Congenital heart disease (CHD) is the most common congenital defect in human beings. The purpose of this article is to investigate impact of an integrated management mode of 'prenatal diagnosis-postnatal treatment' on birth, surgery, prognosis and complications associated with critical CHD (CCHD) in newborns. METHODS: A retrospective analysis of the medical records of newborns diagnosed with CCHD were divided into two groups: prenatal diagnosis and postnatal diagnosis. The demographics, clinical characteristics, surgical status, prognosis and complications of the two groups were compared and the differences identified. RESULTS: Among the 290 newborns with CCHD, 97 (33.4%) were prenatally diagnosed and 193 (66.6%) were postnatally diagnosed. Newborns in the prenatal diagnostic group were hospitalized immediately after birth, whereas the median age of admission was 6.00 (3.00-12.00) days in postnatal diagnostic group, P=0.000. In terms of postnatal symptoms and signs, the incidence of anhelation, cyanosis and cardiac murmur was higher in the postnatal diagnostic group. The rates of preoperative intubation, postoperative open chest exploration and treatment abandonment were higher in the postnatal diagnostic group. The postnatal diagnostic group was more prone to postoperative complications, such as pneumonia and hypoxic-ischemic brain damage. The preoperative mortality [0 (0.0%) vs. 12 (6.2%), P=0.028] in the prenatal diagnostic group was lower than that in the postnatal diagnostic group. And the one-year survival rate of the prenatal diagnostic group was higher (log-rank test P=0.034). CONCLUSIONS: The integrated management mode of prenatal diagnosis-postnatal treatment can improve postnatal symptoms, reduces complications, reduces preoperative mortality and increases one-year survival rates in newborns with CCHD.

The Application of a Bone Marrow Mesenchymal Stem Cell Membrane in the Vascularization of a Decellularized Tracheal Scaffold.

Airway stenosis is a common problem in the neonatal intensive care unit (NICU) and pediatric intensive care unit (PICU). A tissue-engineered trachea is a new therapeutic method and a research hotspot. Successful vascularization is the key to the application of a tissue-engineered trachea. However, successful vascularization studies lack a complete description. In this study, it was assumed that rabbit bone marrow mesenchymal stem cells were obtained and induced by ascorbic acid to detect the tissue structure, ultrastructure, and gene expression of the extracellular matrix. A vascular endothelial cell culture medium was added in vitro to induce the vascularization of the stem cell sheet (SCS), and the immunohistochemistry and gene expression of vascular endothelial cell markers were detected. At the same time, vascular growth-related factors were added and detected during SCS construction. After the SCS and decellularized tracheal (DT) were constructed, a tetrandrine allograft was performed to observe its vascularization potential. We established the architecture and identified rabbit bone marrow mesenchymal stem cell membranes by 14 days of ascorbic acid, studied the role of a vascularized membrane in inducing bone marrow mesenchymal stem cells by in vitro ascorbic acid, and assessed the role of combining the stem cell membranes and noncellular tracheal scaffolds in vivo. Fourteen experiments confirmed that cell membranes promote angiogenesis at gene level. The results of 21-day in vitro experiments showed that the composite tissue-engineered trachea had strong angiogenesis. In vivo experiments show that a composite tissue-engineered trachea has strong potential for angiogenesis. It promotes the understanding of diseases of airway stenosis and tissue-engineered tracheal regeneration in newborns and small infants.

The high-risk factors of different severities of bronchopulmonary dysplasia (BPD) based on the national institute of child health and human development (NICHD) diagnosis criteria in 2018 / Os fatores de alto risco de diferentes gravidades de displasia broncopulmonar (DBP) com base no instituto nacional de saúde infantil e desenvolvimento humano (NICHD): critérios de diagnóstico em 2018

ABSTRACT Objective To investigate the clinical characteristics of preterm infants with different severities of bronchopulmonary dysplasia (BPD) and disclose the high-risk factors of exacerbating BPD. Methods Collection of clinical data of 91 preterm infants admitted to the NICU and diagnosed with BPD, categorized in groups according to the disease severity: 41 mild cases,, 24 moderate cases, and 26 severe cases. Comparison and analysis of perinatal risk factors, treatment, complications and prognosis of the infants with different severity degrees. Results The severe group had a higher proportion of infants with congenital heart disease (CHD) higher than the moderate group (P < 0.05), and a higher ratio of pneumonia and mechanical ventilation (MV) ≥ seven days than the mild group (P < 0.05). The severe group also presented higher reintubation incidence than both the mild and moderate groups (P < 0.05). The groups presented different (P < 0.05) incidence rates of hemodynamically significant patent ductus arteriosus (hsPDA) . Ridit analysis suggested that the premature infants (PIs) with hsPDA, multiple microbial pulmonary infections, or Klebsiella pneumoniae pneumonia had more severe illness. Conclusion CHD, hsPDA, MV ≥ seven days, reintubation, pneumonia, especially multiple microbial pulmonary infections, and Klebsiella pneumoniae pneumonia are correlated with the severity of BPD and can be used as BPD progression predictor.

RESUMO Objetivo Investigar as características clínicas de prematuros com diferentes gravidades de displasia broncopulmonar (DBP) e divulgar os fatores de alto risco para a DBP. Métodos Coleta de dados clínicos de 91 prematuros internados em UTIN com diagnóstico de DBP, categorizados em grupos de acordo com a gravidade da doença: 41 casos leves, 24 casos moderados e 26 casos graves. Foram feitas a comparação e a análise de fatores de risco perinatais, tratamento, complicações e prognóstico de lactentes com diferentes graus de gravidade. Resultados O grupo grave teve uma proporção maior de bebês com doença cardíaca congênita (DCC) do que o grupo moderado (p < 0,05) e com pneumonia e ventilação mecânica (VM) ≥ 7 dias do que o grupo leve (p < 0,05). O grupo grave também apresentou maior incidência de reintubação do que os grupos leve e moderado (p < 0,05). Os grupos apresentaram diferentes (p < 0,05) taxas de incidência de persistência do canal arterial hemodinamicamente significativa (PCAhs). A análise de ridit sugeriu que os bebês prematuros (BPs) com PCAhs, infecções pulmonares microbianas múltiplas ou pneumonia por Klebsiella pneumoniae tinham doenças mais graves. Conclusão DCC, PCAhs, VM ≥ 7 dias, reintubação, pneumonia, principalmente infecções pulmonares microbianas múltiplas, e pneumonia por Klebsiella pneumoniae estão correlacionadas com a gravidade da DBP e podem ser usadas como preditoras de progressão da DBP.

The interactions of spore-coat morphogenetic proteins studied by single-molecule recognition force spectroscopy.

Bacillus subtilis can form a spore, which is a dormant type of cell, when its external environment becomes unsuitable for vegetative growth. The spore is surrounded by a multilayered proteinaceous shell called a spore coat, which plays a crucial role in dormancy and germination. Of the over 70 proteins that form the spore coat, only a small subset of them affect its morphogenesis; they are referred to as morphogenetic proteins. How these morphogenetic proteins interact, and furthermore, how they build the ordered, functional coat layers is not well understood. Elucidating the self-assembly mechanism of individual proteins into such a complex structure may contribute to its potential use in nano-biotechnology applications for preparing highly organized, robust, and resistant proteinaceous layers. Herein, direct, noncovalent, low-affinity interactions between the spore-coat morphogenetic proteins SpoIVA, SpoVID, and SafA were studied by using single-molecule recognition force spectroscopy in vitro for the first time. Based on the real-time examination of interactions between these three proteins, a series of dynamic kinetic data were obtained. It was also observed that the SafA-SpoVID interaction was stronger than that of SafA-SpoIVA.