Potential effects of biomaterials on macrophage function and their signalling pathways.

The use of biomaterials in biomedicine and healthcare has increased in recent years. Macrophages are the primary immune cells that induce inflammation and tissue repair after implantation of biomaterials. Given that macrophages exhibit high heterogeneity and plasticity, the influence of biomaterials on macrophage phenotype should be considered a crucial evaluation criterion during the development of novel biomaterials. This review provides a comprehensive summary of the physicochemical, biological, and dynamic characteristics of biomaterials that drive the regulation of immune responses in macrophages. The mechanisms involved in the interaction between macrophages and biomaterials, including endocytosis, receptors, signalling pathways, integrins, inflammasomes and long non-coding RNAs, are summarised in this review. In addition, research prospects of the interaction between macrophages and biomaterials are discussed. An in-depth understanding of mechanisms underlying the spatiotemporal changes in macrophage phenotype induced by biomaterials and their impact on macrophage polarization can facilitate the identification and development of novel biomaterials with superior performance. These biomaterials may be used for tissue repair and regeneration, vaccine or drug delivery and immunotherapy.

Acute Respiratory Distress Syndrome Induced by White Smoke Inhalation: a Potential Animal Model For Evaluating Pathological Changes and Underlying Mechanisms.

BACKGROUND/AIMS: White smoke inhalation (WSI) is an uncommon but potentially deadly cause of acute respiratory distress syndrome (ARDS). However, no clinical treatment protocol has been established for the treatment of WSI-induced ARDS. Therefore, it is necessary to investigate the effects of WSI in ARDS and the mechanisms underlying the effects of WSI to determine a novel therapeutic target. METHODS: On the basis of the duration of continued inhalation of white smoke (3 min, 5 min, and 7 min), rats were divided into three groups (WSI-3 min, WSI-5 min, and WSI-7 min). The survival rate, pathological change, and computed tomography (CT) score were evaluated to determine the modeling conditions. In the established WSI-5 min models, evaluations were performed to evaluate the following: arterial blood gas levels, lung wet/dry weight ratio, the expression of inflammatory cytokines, and the effect of NF-κB signaling pathway. RESULTS: The survival rate of rats at 72 h post-WSI in the WSI-3 min, WSI-5 min, and WSI-7 min groups was 83.33%, 75%, and 25%, respectively. Results from evaluation of H&E staining, CT scan, arterial blood gas levels, and lung wet/dry weight ratio suggest that the pathological changes in the rat in the WSI-5 min and WSI-7 min groups are very similar to those in patients with ARDS induced by WSI. Additionally, the expression of INF-γ, TGF-ß1, TNF-α, and IL-1ß were increased, and the NF-κB signaling pathway was activated in the WSI-5 min group. CONCLUSION: The rat model of WSI-5 min can be used as a WSI-induced ALI model for further experiments. The NF-κB signaling pathway may be a potential therapeutic target for the treatment of WSI- induced ARDS.

[The preventive and therapeutic effect of advanced airway management on pulmonary infection in patients with inhalation injury after tracheotomy].

OBJECTIVE: To observe the preventive and therapeutic effect of advanced airway management on pulmonary infection in patients with inhalation injury after tracheotomy. METHODS: fourteen burn patients with inhalation injury admitted to our hospital from January 2001 to December 2004 were enrolled as control (C) group, and they were treated with conventional systemic therapy and management of airway. Twenty-seven burn patients with inhalation injury admitted to our hospital from January 2005 to October 2009 were enrolled as advanced (A) group, and they were treated with conventional systemic therapy and advanced airway management, including bedside isolation of airway, fixation of both oxygen supply tube and humidifying tube, humidification in specific body position, thinning of sputum, lavement of airway and procedural sputum elimination, steam inhalation combined with medicine, and suction of sputum with interrupted negative pressure. Result of bacterial culture of sputum (the 7th day after tracheotomy) and chest X-ray (at admission and the 7th day after tracheotomy), pulmonary infection, change in blood gas analysis index and oxygen saturation (SO(2)), (within 7 days after tracheotomy), and the number of patients curd in 2 groups were observed and compared. RESULTS: (1) Positive result of bacterial culture of sputum was observed in 11 (78.6%) patients in C group and 12 (44.4%) patients in A group. The difference between them was statistically significant (chi(2) = 4.36, P < 0.05). The main bacterium detected was Pseudomonas aeruginosa. (2) Pneumonia was suspected in 7 patients (25.9%) in A group by chest X-ray, which was obviously fewer than that in C group (8 Cases, 57.1%, chi(2) = 3.87, P < 0.05). The result was in accordance with the diagnosis of pulmonary infection. (3) No CO(2) retention, SO(2) and PaCO(2) abnormality caused by asphyxia was observed in 2 groups, PaCO(2) value in A group was close to that in C group (t = 0.89, P > 0.05). (4) In C group, 9 (64.3%) patients were cured, 5 patients died of pneumonia, wound sepsis, and MODS. In A group, 25 (92.6%) patients were cured, 2 patients died of MODS. Number of cure was obviously larger in A group than in C group (chi(2)= 5.22, P < 0.05). CONCLUSIONS: The advanced airway management has better effects on isolation and humidification of airway, and thinning, drainage, and elimination of sputum. And it can decrease the probability of blind suction and injury to airway, and it prevents pulmonary infection following tracheotomy.