Inflammation-Responsive Hydrogel Accelerates Diabetic Wound Healing through Immunoregulation and Enhanced Angiogenesis.

Angiogenesis is a prominent component during the highly regulated process of wound healing. The application of exogenous vascular endothelial growth factor (VEGF) has shown considerable potential in facilitating angiogenesis. However, its effectiveness is often curtailed due to chronic inflammation and severe oxidative stress in diabetic wounds. Herein, an inflammation-responsive hydrogel incorporating Prussian blue nanoparticles (PBNPs) is designed to augment the angiogenic efficacy of VEGF. Specifically, the rapid release of PBNPs from the hydrogel under inflammatory conditions effectively alleviates the oxidative stress of the wound, therefore reprogramming the immune microenvironment to preserve the bioactivity of VEGF for enhanced angiogenesis. In vitro and in vivo studies reveal that the PBNPs and VEGF co-loaded hydrogel is biocompatible and possesses effective anti-inflammatory properties, thereby facilitating angiogenesis to accelerate the wound healing process in a type 2 diabetic mouse model.

Models predicting mortality risk of patients with burns to ≥ 50% of the total body surface.

BACKGROUND: Several models predicting mortality risk of burn patients have been proposed. However, models that consider all such patients may not well predict the mortality of patients with extensive burns. METHOD: This retrospective multicentre study recruited patients with extensive burns (≥ 50% of the total body surface area [TBSA]) treated in three hospitals of Eastern China from 1 January 2016 to 30 June 2022. The performances of six predictive models were assessed by drawing receiver operating characteristic (ROC) and calibration curves. Potential predictors were sought via "least absolute shrinkage and selection operator" regression. Multivariate logistic regression was employed to construct a predictive model for patients with burns to ≥ 50% of the TBSA. A nomogram was prepared and the performance thereof assessed by reference to the ROC, calibration, and decision curves. RESULT: A total of 465 eligible patients with burns to ≥ 50% TBSA were included, of whom 139 (29.9%) died. The FLAMES model exhibited the largest area under the ROC curve (AUC) (0.875), followed by the models of Zhou et al. (0.853) and the ABSI model (0.802). The calibration curve of the Zhou et al. model fitted well; those of the other models significantly overestimated the mortality risk. The new nomogram includes four variables: age, the %TBSA burned, the area of full-thickness burns, and blood lactate. The AUCs (training set 0.889; internal validation set 0.934; external validation set 0.890) and calibration curves showed that the nomogram exhibited an excellent discriminative capacity and that the predictions were very accurate. CONCLUSION: For patients with burns to ≥ 50％of the TBSA, the Zhou et al. and FLAMES models demonstrate relatively high predictive ability for mortality. The new nomogram is sensitive, specific, and accurate, and will aid rapid clinical decision-making.

Ultra-restrictive red blood cell transfusion strategies in extensively burned patients.

In recent years, due to the shortage of blood products, some extensive burn patients were forced to adopt an "ultra-restrictive" transfusion strategy, in which the hemoglobin levels of RBC transfusion thresholds were < 7 g/dl or even < 6 g/dl. This study investigated the prognostic impacts of ultra-restrictive RBC transfusion in extensive burn patients. This retrospective multicenter cohort study recruited extensive burns (total body surface area ≥ 50%) from three hospitals in Eastern China between 1 January 2016 and 30 June 2022. Patients were divided into an ultra-restrictive transfusion group and a restrictive transfusion group depending on whether they received timely RBC transfusion at a hemoglobin level < 7 g/dl. 1:1 ratio propensity score matching (PSM) was performed to balance selection bias. Modified Poisson regression and linear regression were conducted for sensitive analysis. Subsequently, according to whether they received timely RBC transfusion at a hemoglobin level < 6 g/dl, patients in the ultra-restrictive transfusion group were divided into < 6 g/dl group and 6-7 g/dl group to further compare the prognostic outcomes. 271 eligible patients with extensive burns were included, of whom 107 patients were in the ultra-restrictive transfusion group and 164 patients were in the restrictive transfusion group. The ultra-restrictive transfusion group had a significantly lower RBC transfusion volume than the restrictive transfusion group (11.5 [5.5, 21.5] vs 17.3 [9.0, 32.5] units, p = 0.004). There were no significant differences between the two groups in terms of in-hospital mortality, risk of infection, hospital length of stay, and wound healing time after PSM or multivariate adjustment (p > 0.05). Among the ultra-restrictive transfusion group, patients with RBC transfusion threshold < 6 g/dl had a significantly higher hospital mortality than 6-7 g/dl (53.1% vs 21.3%, p = 0.001). For extensive burn patients, no significant adverse effects of ultra-restrictive RBC transfusion were found in this study. When the blood supply is tight, it is acceptable to adopt an RBC transfusion threshold of < 7 g/dL but not < 6 g/dL.

Nanosilver alleviates foreign body reaction and facilitates wound repair by regulating macrophage polarization. / 纳米银通过调控巨噬细胞极化以减轻异物反应并促进创面修复.

Foreign body reactions induced by macrophages often cause delay or failure of wound healing in the application of tissue engineering scaffolds. This study explores the application of nanosilver (NAg) to reduce foreign body reactions during scaffold transplantation. An NAg hybrid collagen-chitosan scaffold (NAg-CCS) was prepared using the freeze-drying method. The NAg-CCS was implanted on the back of rats to evaluate the effects on foreign body reactions. Skin tissue samples were collected for histological and immunological evaluation at variable intervals. Miniature pigs were used to assess the effects of NAg on skin wound healing. The wounds were photographed, and tissue samples were collected for molecular biological analysis at different time points post-transplantation. NAg-CCS has a porous structure and the results showed that it could release NAg constantly for two weeks. The NAg-CCS group rarely developed a foreign body reaction, while the blank-CCS group showed granulomas or necrosis in the subcutaneous grafting experiment. Both matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were reduced significantly in the NAg-CCS group. The NAg-CCS group had higher interleukin (IL)-10 and lower IL-6 than the blank CCS group. In the wound healing study, M1 macrophage activation and inflammatory-related proteins (inducible nitric oxide synthase (iNOS), IL-6, and interferon-|γ (IFN-|γ)) were inhibited by NAg. In contrast, M2 macrophage activation and proinflammatory proteins (arginase-1, major histocompatibility complex-II (MHC-II), and found in inflammatory zone-1 (FIZZ-1)) were promoted, and this was responsible for suppressing the foreign body responses and accelerating wound healing. In conclusion, dermal scaffolds containing NAg suppressed the foreign body reaction by regulating macrophages and the expression of inflammatory cytokines, thereby promoting wound healing.

Triage and Evaluation of Blast-Injured Patients in Wenling Liquefied Petroleum Gas Tanker Explosion.

On June 13, 2020, a liquefied petroleum gas tanker exploded in Wenling. Here, the authors describe the mass casualty emergency response to the explosion. The authors collected the medical records of 176 inpatients at 8 hospitals in Taizhou and Hangzhou. The 176 inpatients with blast injuries comprised 70 females and 106 males, with an average age of 45.48 ± 19.96 years, and more than half of the patients were farmers. They were transported to six hospitals distributed around the explosion site in Taizhou in the initial rescue period and were grouped according to their new injury severity score as having mild, moderate, severe, or extremely severe injuries. Most patients with severe and extremely severe injuries were admitted to a superior hospital for postsecondary triage. Forty-four patients experienced primary blast injuries, 137 experienced secondary blast injuries, 37 experienced tertiary blast injuries, and 40 patients experienced quaternary blast injuries. Multiple blast injuries were suffered by 62 patients. Most patients (95.45%) suffered external injuries, with the chest, extremities, and face as the main affected areas. Burns were diagnosed in 26 adults, of whom 15.38%, 19.23%, 7.70%, and 57.69% suffered mild, moderate, severe, and extremely severe cases. Sixteen burn patients suffered from burn-blast injuries. Upper limbs and the head/face/neck area, as exposed areas, were more likely to experience a burn injury. Inhalation was the main accompanying injury. Of the eight patients who died in the prehospital session, seven had burn injuries. This report on the accident and injury characteristics of an open-air LPG-related explosion will facilitate responses to subsequent catastrophes.

Use of the Braden Scale to Predict Injury Severity in Mass Burn Casualties.

BACKGROUND Mass burn casualties impose an enormous burden on triage systems. The triage capacity of the Braden Scale for detecting injury severity has not been evaluated in mass burn casualties. MATERIAL AND METHODS The New Injury Severity Score (NISS) was used to dichotomize the injury severity of patients. The Braden Scale and other potentially indicative measurement tools were evaluated using univariate analysis and multivariate logistic regression. The relationships between the Braden Scale and other continuous variables with injury severity were further explored by correlation analysis and fitted with regression models. Receiver operating characteristic (ROC) curve analysis was used to validate triage capacity and compare prognostic accuracy. RESULTS A total of 160 hospitalized patients were included in our study; 37 were severely injured, and 123 were not. Injury severity was independently associated with the Numerical Rating Scale (adjusted OR, 1.816; 95% CI, 1.035-3.187) and Braden Scale (adjusted OR, 0.693; 95% CI, 0.564-0.851). The ROC curve of the fitted quadratic model of the Braden Scale was 0.896 (0.840-0.953), and the cut-off value was 17. The sensitivity was 81.08% (64.29-91.44%) and the specificity was 82.93% (74.85-88.89%). Comparison of ROC curves demonstrated an infinitesimal difference between the Braden Scale and NISS for predicting 30-day hospital discharge (Z=0.291, P=0.771) and Intensive Care Unit admission (Z=2.016, P=0.044). CONCLUSIONS The Braden Scale is a suitable triage tool for predicting injury severity and forecasting disability-related outcomes in patients affected by mass burn casualty incidents.

Multi-Pitch Liquid Crystal Filters with Single Layer Polymer Template.

Multi-reflective peak and bandwidth scalable liquid crystal (LC) filters were investigated. By refilling a cholesteric LC (CLC) whose chiral pitch is different to the target template into a blue phase LC (BPLC) template, a multi-reflective peak single layer LC filter can be fabricated. With multiple templating and refilling processes, the number of reflective peaks can be further increased. Moreover, by refilling the CLCs of designed chiral pitch into a CLC template sequentially, a bandwidth scalable single layer CLC filter can be fabricated. The LC filters show great potential applications in optical communication, display, and LC lasing.

High SNR fingerprinting structure for LC displays.

An optical fingerprinting solution with a switchable backlight is demonstrated for liquid crystal displays (LCDs). In fingerprinting mode, the collimated infrared light is applied to improve the signal-noise ratio (SNR) between the valley and ridge of the fingerprint. Compared with the conventional backlight, the proposed structure can effectively improve the SNR. Furthermore, the fingerprinting mode and the display mode may work at the same time without interference because of the different wavelengths and light paths. It shows the great potential application of LCD-based optical fingerprints.

Pyridinium porphyrins and AuNPs mediated bionetworks as SPR signal amplification tags for the ultrasensitive assay of brain natriuretic peptide.

Extension of the self-assembled bionanonetworks into surface plasmon resonance (SPR) assay investigation provides an effective signal amplification approach. We fabricated a bionetwork by nucleic acids, organic compounds, and supramolecular gold nanoparticles for ultrasensitive SPR detection of B-type natriuretic peptide (BNP). The SPR method was developed by a sandwich-type format of aptamer-target-antibody, and the aptamer-modified bionanonetworks induced localized SPR and large refractive index for different concentrations of the target BNP. The linear concentration range and limit of detection were 1-10,000 pg/mL (R2 = 0.9852) and 0.3 pg/mL respectively. The detection recovery was in the range 92.13 to 108.69%. The approach embraces the following main advantages: (1) Cooperative double recognition was realized by calix[4]arenes for amino aptamers and pyridinium porphyrins. (2) The approach provided the specificity for supramolecular-based nanomaterials and a simple synthesis process via the ordered self-assembly under mild conditions. (3) The bionanonetworks endowed the SPR assay with signal amplification and stable determination for trace proteins. Therefore, it is expected that this study may offer a new SPR signal-amplified platform of organic-inorganic bionanonetworks to achieve sensitive, stable, and real-time determination. Graphical abstract Schematic of bionanonetwork based on porphyrin-mediated functionalized gold nanoparticles for SPR signal amplification to quantitatively detect BNP.

Inorganic and Metal-Organic Nanocomposites for Cascade-Responsive Imaging and Photochemical Synergistic Effects.

Porphyrins coordinated with platinum(II) chemotherapeutic drugs are attractive for the development of photosensitizers for photodynamic therapy (PDT) of cancer. In this paper, inorganic and metal-organic nanocomposites were synthesized with cascade-responsive imaging and photochemical synergistic effects. After endo/lysosomal escape, the outer metal-organic frameworks were degraded, leading to the release of an excellent photosensitizer (tetrapyridylporphyrin, PtTPyP). Subsequently, doxorubicin (DOX), inserted in the adenosine triphosphate (ATP) aptamer-functionalized gold nanoparticles, was released under the stimulation of endogenous ATP, synergistically enhancing cancer treatment. Fluorescence imaging allowed tracking of PtTPyP and DOX for real-time detection and on-demand therapy. This strategy endowed the nanocomposites with stability, responsiveness, effectiveness, and ease of synthesis, namely, sTREE strategy. Accordingly, our demonstration provided a promising and smart nanocarrier for imaging and drug delivery.

Cell membrane-coated gold nanoparticles for apoptosis imaging in living cells based on fluorescent determination.

A nanoprobe was developed to achieve apoptosis detection by cell membrane-functionalized gold nanoparticles (AuNP-pep@Mem). The fluorescence of the fluorescein isothiocyanate isomer I (FITC)-labeled caspase-3 substrates was quenched by the attachment to AuNPs. The fluorescence signal was recovered via the cleavage of caspase-3 under apoptotic conditions. It exhibited a low detection limit of 1.3 pg·mL-1 with a linear range from 3.2 to 100 pg·mL-1 for caspase-3 detection with excitation wavelength of 490 nm. After wrapped by the cell membrane, the nanoprobe was effectively delivered into cells with high cell permeability. AuNP-pep@Mem nanoprobe provided signal enhancement of 1.8 times in living cells compared to non-membrane-coated nanoparticles (AuNP-pep). In combination with its excellent stability, low LOD and good specificity, the AuNP-pep@Mem probe can be an ideal probe for fluorescence imaging of apoptosis. Graphical abstractSchematic representation of fluorescent determination for apoptosis in living cells based on cell membrane-coated gold nanoparticls.

[Experimental research on the compatibility of self-assembly nanofiber hydrogel from the amphipathic peptide containing IKVAV with olfactory ensheathing cells of rats].

The present research was aimed to explore the biocompatibility of IKVAV self-assembling peptide nanofiber scaffold with olfactory ensheathing cells (OECs) of rats. The OECs were seeded onto the surface of coverslips covered with IKVAV self-assembling peptide nanofiber scaffold hydrogel (2D culture system), and implanted within IKVAV self-assembling peptide nanofiber scaffold hydrogel (3D culture system), respectively. The adhesion, viability of OECs were observed with inverted microscope. Then the characteristics for survival and adhesion of cells by image processing were observed, and statistical analysis on the number of S-100 positive cell, the area of the cell bodies and the perimeter of the cell and MTT method were carried out. It was found that the OECs could survive and migrate in IKVAV self-assembling peptide nanofiber scaffold. The result of the cell MTT exam, of the shape and quantity of cells had no significant difference compared to those of the OECs cultured with poly-L-lysine (PLL). It has been proved that IKVAV self-assembling peptide nanofiber scaffold has good biocompatibility with rat OECs.