Endogenous stimuli-responsive separating microneedles to inhibit hypertrophic scar through remodeling the pathological microenvironment.

Hypertrophic scar (HS) considerably affects the appearance and causes tissue dysfunction in patients. The low bioavailability of 5-fluorouracil poses a challenge for HS treatment. Here we show a separating microneedle (MN) consisting of photo-crosslinked GelMA and 5-FuA-Pep-MA prodrug in response to high reactive oxygen species (ROS) levels and overexpression of matrix metalloproteinases (MMPs) in the HS pathological microenvironment. In vivo experiments in female mice demonstrate that the retention of MN tips in the tissue provides a slowly sustained drug release manner. Importantly, drug-loaded MNs could remodel the pathological microenvironment of female rabbit ear HS tissues by ROS scavenging and MMPs consumption. Bulk and single cell RNA sequencing analyses confirm that drug-loaded MNs could reverse skin fibrosis through down-regulation of BCL-2-associated death promoter (BAD), insulin-like growth factor 1 receptor (IGF1R) pathways, simultaneously regulate inflammatory response and keratinocyte differentiation via up-regulation of toll-like receptors (TOLL), interleukin-1 receptor (IL1R) and keratinocyte pathways, and promote the interactions between fibroblasts and keratinocytes via ligand-receptor pair of proteoglycans 2 (HSPG2)-dystroglycan 1(DAG1). This study reveals the potential therapeutic mechanism of drug-loaded MNs in HS treatment and presents a broad prospect for clinical application.

Identification and validation of CCR5 linking keloid with atopic dermatitis through comprehensive bioinformatics analysis and machine learning.

There is sufficient evidence indicating that keloid is strongly associated with atopic dermatitis (AD) across ethnic groups. However, the molecular mechanism underlying the association is not fully understood. The aim of this study is to discover the underlying mechanism of the association between keloid and AD by integrating comprehensive bioinformatics techniques and machine learning methods. The gene expression profiles of keloid and AD were downloaded from the Gene Expression Omnibus (GEO) database. A total of 449 differentially expressed genes (DEGs) were found to be shared in keloid and AD using the training datasets of GEO (GSE158395 and GSE121212). The hub genes were identified using the protein-protein interaction network and Cytoscape software. 20 of the most significant hub genes were selected, which were mainly involved in the regulation of the inflammatory and immune response. Through two machine learning algorithms of LASSO and SVM-RFE, CCR5 was identified as the most important key gene. Subsequently, upregulated CCR5 gene expression was confirmed in validation GEO datasets (GSE188952 and GSE32924) and clinical samples of keloid and AD. Immune infiltration analysis showed that T helper (Th) 1, 2 and 17 cells were significantly enriched in the microenvironment of both keloid and AD. Positive correlations were found between CCR5 and Th1, Th2 and Th17 cells. Finally, two TFs of CCR5, NR3C2 and YY1, were identified, both of which were downregulated in keloid and AD tissues. Our study firstly reveals that keloid and AD shared common inflammatory and immune pathways. Moreover, CCR5 plays a key role in the pathogenesis association between keloid and AD. The common pathways and key genes may shed light on further mechanism research and targeted therapy, and may provide therapeutic interventions of keloid with AD.

Self-Adhesive Hyaluronic Acid/Antimicrobial Peptide Composite Hydrogel with Antioxidant Capability and Photothermal Activity for Infected Wound Healing.

Bacterial infection can delay wound healing, causing wounds to deteriorate and even threaten the patient's life. Recently, although many composite hydrogels as wound dressing have been developed, it is still highly desired to construct photothermal hydrogels with antimicrobial and antioxidant properties to accelerate the infected wound healing. In this work, a hyaluronic acid (HA)-based composite hydrogel consisting of a dopamine-substituted antimicrobial peptide (DAP) and Iron (III) ions is developed, which exhibits photothermal-assisted promotion and acceleration of healing process of bacteria-infected wounds. DAP, serving as both antimicrobial agent and ROS-scavenger, forms Schiff's base bonds with aldehyde hyaluronic acid (AHA) and iron-catechol coordination bonds to reinforce the composite hydrogel. The presence of Fe3+ can also promote covalent polymerization of dopamine, which endows the hydrogel with photothermal capacity. The in vitro and in vivo experiments prove that the composite hydrogel can effectively accelerate the infected wound healing process, including antibacterial, accelerated collagen deposition, and re-epithelization. This study suggests that the multifunctional composite hydrogel possesses remarkable potential for bacteria-infected wound healing by combining inherent antimicrobial activity, antioxidant capability, and photothermal effect.

Comparing the Accuracy of ABCD-10 and SCORTEN in Predicting the In-Hospital Mortality of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis: A Multi-Institutional Study from Central China.

BACKGROUND: The newly described ABCD-10 (age, bicarbonate, cancer, dialysis, 10% body surface area [BSA]) is a 5-item mortality prediction model for patients with Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN). It was developed in the United States, has at present been externally tested only in the United States, Spain, and Singapore, and remains to be validated in resource-restricted settings. We sought to compare the accuracy of ABCD-10 and Score of Toxic Epidermal Necrolysis (SCORTEN) in predicting in-hospital mortality in a cohort from central China. Due to disease progression affecting the accuracy of the prediction model during hospitalization, for example, higher predictive accuracy of SCORTEN based on parameters collected on day 3 of hospitalization, we also assessed the overall predictive value of ABCD-10 on days 1 and 3, respectively. METHODS: A retrospective study was performed over a 10-year period (2010-2020) from 3 medical institutions in Wuhan. The performance of predictive models was assessed by both discrimination and calibration. Receiver-operating characteristic (ROC) curves, Hosmer-Lemeshow goodness-of-fit tests and calibration plots were used to evaluate the model discrimination and calibration. RESULTS: Of 84 included patients, 11 (13.1%) did not survive. The discrimination power of ABCD-10 was not significantly different from that of SCORTEN (area under the curve: day 1, p > 0.05; day 3, p > 0.05). Although the calibration of ABCD-10 was good, it was inferior to SCORTEN as it underestimated total mortality (Hosmer-Lemeshow goodness-of-fit test: day 1, p = 0.17 vs. p = 0.63; day 3, p = 0.35 vs. p = 0.93). Besides, the performance of ABCD-10 was slightly better on day 3 relative to day 1. During hospitalization, bacteremia developed in 21 (25.0%) patients, which was associated with a higher risk of death in our cohort (odds ratio, 22.88; 95% CI, 4.38-119.40; p < 0.001). CONCLUSION: ABCD-10 showed acceptable overall performance, but revealed mortality underestimation and was inferior to the performance of SCORTEN. In consistence with SCORTEN, ABCD-10 was a better model when using values collected at day 3 of hospitalization relative to day 1.

Injectable and pH-Sensitive Hyaluronic Acid-Based Hydrogels with On-Demand Release of Antimicrobial Peptides for Infected Wound Healing.

Antibiotics' abuse in bacteria-infected wounds has threatened patients' lives and burdened medical systems. Hence, antibiotic-free hydrogel-based biomaterials, which exhibit biostability, on-demand release of antibacterial agents, and long-lasting antimicrobial activity, are highly desired for the treatment of chronic bacteria-infected wounds. Herein, we developed a hyaluronic acid (HA)-based composite hydrogel, with an antimicrobial peptide [AMP, KK(SLKL)3KK] as a cross-linking agent through Schiff's base formation, which exhibited an acidity-triggered release of AMP (pathological environment in bacteria-infected wounds, pH ∼ 5.5-5.6). During the self-assembly process, AMP adopted an antiparallel ß-sheet secondary structure due to the alternate arrangement of hydrophobic and hydrophilic residues of amino acids. Owing to Schiff's base formation between the primary amines derived from lysine residues and the aldehydes in oxidized HA, the AMP-HA composite hydrogel exhibited injectability, high biostability, and enhanced mechanical strength. Importantly, both AMP and the AMP-HA composite showed excellent broad-spectrum antibacterial activity in vitro and in vivo. Specifically, the AMP-HA composite hydrogel exhibited on-demand full thickness wound healing in an infected mice model. Therefore, this work provides an efficient strategy to fabricate antibiotic-free hydrogel-based biomaterials for the management of chronic bacteria-infected wounds.

Dopamine-Substituted Multidomain Peptide Hydrogel with Inherent Antimicrobial Activity and Antioxidant Capability for Infected Wound Healing.

Wound infection can cause a delay in wound healing or even wound deterioration, threatening patients' lives. The excessive accumulation of reactive oxygen species (ROS) in infected wounds activates a strong inflammatory response to delay wound healing. Therefore, it is highly desired to develop hydrogels with inherent antimicrobial activity and antioxidant capability for infected wound healing. Herein, a dopamine-substituted multidomain peptide (DAP) with inherent antimicrobial activity, strong skin adhesion, and ROS scavenging has been developed. DAP can form bilayer ß-sheets with dopamine residues on the surface of nanofibers. The enhanced rheological properties of DAP-based hydrogel can be achieved not only through UV irradiation but also by incorporation of multivalent ions (e.g., PO43-). Furthermore, the DAP hydrogel shows a broad spectrum of antimicrobial activity due to the high positive charges of lysine residues and the ß-sheet formation. When applied to full-thickness dermal wounds in mice, the DAP hydrogel results in a significantly shortened inflammatory stage of the healing process because of its remarkable antimicrobial activity and antioxidant capability. Accelerated wound closure with thick granulation tissue, uniform collagen arrangement, and dense vascularization can be achieved. This work suggests that the DAP hydrogel can serve as antimicrobial coating and ROS-scavenging wound dressing for bacterial-infected wound treatment.

Prognostic significance of tumor size for primary invasive cutaneous melanoma: A population-based study, 2004-2016.

BACKGROUND: This study aimed to assess the independent prognostic value of tumor size compared with other clinical and pathologic features of primary invasive cutaneous melanoma (CM). METHODS: This study included 28,593 patients with primary invasive CM in Surveillance, Epidemiology, and End Results Program database diagnosed from 2004 through 2016. Tumor size was divided into five subgroups (≤6, 7-12, 13-30, 31-42, and >42 mm). The primary endpoint was melanoma-specific survival (MSS). RESULTS: The relationship between tumor size and survival was piecewise. After adjusting for age, sex, primary site, histopathologic cell type, Breslow thickness, ulceration, mitotic rate, regional metastasis, and distant metastasis, the hazard ratio (HR) of MSS increased with increasing tumor size until a peak at 31-42 mm (HRs, 1.33, 1.59, 2.41, respectively; all P < .0001), and then decreased when tumor size was larger than 42 mm using tumor size ≤ 6 mm as the reference (HR, 2.11; 95% confidence interval [CI], 1.84 -2.42; P < .0001). This pattern mostly remained after stratification by T subcategories from T1 to T4 in localized primary CM except that tumor size >42 mm subgroup had the shortest MSS in T4. In addition, tumor size with a cutoff value of 12 mm showed stronger prognostic value for MSS (HR, 2.32; 95% CI, 1.80-2.98; P < .0001) than Breslow thickness and mitotic rate in primary CM with T1N0M0. CONCLUSIONS: Tumor size was an important independent prognostic factor for MSS in patients with primary invasive CM. Tumor size larger than 30 mm would provide additional and important prognostic information in each T subcategory of localized CM. Furthermore, tumor size with a cutoff value of 12 mm has great potential in improving the accuracy of melanoma T1 substaging.