Superselective Arterial Hyaluronidase Thrombolysis is an Effective Treatment for Hyaluronic Acid-Induced Retinal Artery Occlusion: Study in a Rabbit Model.

BACKGROUND: There are serious complications associated with hyaluronic acid (HA) facial injections, including vision impairment due to retinal artery ischemia. In this study, we put forth a clinically relevant model of retinal ischemia and reperfusion in rabbit. We used this to verify the efficacy of hyaluronidase intra-artery thrombolysis in the treatment of hyaluronic acid-induced retinal artery occlusion. METHODS: Retinal artery ischemia was induced by injecting HA into the ophthalmic artery (OA) of adult chinchilla rabbit, and reperfusion was achieved by intra-artery thrombolysis therapy with hyaluronidase following 60 min and 4 h of occlusion. Digital subtraction angiography (DSA) and fundus fluorescein angiography (FFA) were used to evaluate blood flow in the retina. Electroretinogram (ERG), hematoxylin and eosin staining and transmission electron microscope were used to evaluate the structure and function of the retina after ischemia and reperfusion following 60 min and 4 h of occlusion. RESULTS: DSA and FFA images confirmed occlusion of the ophthalmic and central retinal arteries, as well as reperfusion after hyaluronidase thrombolysis. ERG indicated retinal dysfunction following ischemia, and thrombolysis partially rescued its impairment following 4 h of occlusion. Hematoxylin and eosin staining and TUNEL staining revealed ischemia-induced histological damages in the retina at different time windows, and hyaluronidase thrombolysis partially mitigated these damages. CONCLUSIONS: We report a method to establish a HA-induced retinal artery occlusion animal model. Hyaluronidase intra-artery thrombolysis was used to recanalize the embolized OA at different time points. Using our method, we achieved retinal reperfusion, and an improvement was observed in the visual function of rabbits after hyaluronidase thrombolysis following 4 h of occlusion. We believe that hyaluronidase intra-artery thrombolysis is an effective method to treat HA-induced retinal artery occlusion in clinic. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Percutaneous Intra-arterial Hyaluronidase Injection for Hyaluronic Acid Filler Embolism Threatening Skin Barrier Integrity: Implementation of a Stepwise Treatment Protocol.

BACKGROUND: Hyaluronic acid (HA) filler-induced vascular embolism that threatens skin integrity is an urgent situation. There is increasing evidence that percutaneous intra-arterial hyaluronidase injection is an effective therapeutic technique for it. However, until now, there is a lack of a unifying protocol about the technique. OBJECTIVES: This study aims to provide a conclusion of percutaneous intra-arterial hyaluronidase injection along with adjunctive measures on the treatment of occlusions precipitated by HA-based filler and develop a stepwise treatment protocol. METHODS: We searched PubMed for peer-reviewed studies, consensus statements, case series, and case reports using a variety of keywords. RESULTS: High-dose, pulsed hyaluronidase is the mainstay for the treatment of HA filler-induced embolism, but percutaneous intra-arterial hyaluronidase injection is a more effective technique. Until now, hyaluronidase is injected into three arteries percutaneously, including facial artery, supratrochlear artery, and superficial temporal artery. Furthermore, the adjunctive measures that may optimize clearance of an occlusion and/or skin barrier repair such as the use of image guidance and CGF should be considered. CONCLUSION: Vascular occlusions that threaten skin integrity are an urgent matter which requires accurate diagnosis and effective intervention. Percutaneous intra-arterial hyaluronidase injection along with adjunctive measures performed in a stepwise manner is key to an optimal outcome. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Application of 3D-printed tissue-engineered skin substitute using innovative biomaterial loaded with human adipose-derived stem cells in wound healing.

Large-scale skin injuries are usually accompanied by impaired wound healing, resulting in scar formation, or significant morbidity and mortality. The aim of this study is to explore the in vivo application of 3D-printed tissue-engineered skin substitute using innovative biomaterial loaded with human adipose-derived stem cells (hADSCs) in wound healing. Adipose tissue was decellularized, and extracellular matrix components were lyophilized and solubilized to obtain adipose tissue decellularized extracellular matrix (dECM) pre-gel. The newly designed biomaterial is composed of adipose tissue dECM pre-gel, methacrylated gelatin (GelMA), and methacrylated hyaluronic acid (HAMA). Rheological measurement was performed to evaluate the phase-transition temperature and the storage and loss modulus at this temperature. Tissue-engineered skin substitute loaded with hADSCs was fabricated by 3D printing. We used nude mice to establish full-thickness skin wound healing model and divided them into four groups randomly: (A) Full-thickness skin graft treatment group, (B) 3D-bioprinted skin substitute treatment group as the experimental group, (C) microskin graft treatment group, and (D) control group. The amount of DNA in each milligram of dECM was 24.5 ± 7.1 ng, fulfilling the currently accepted decellularization criteria. The solubilized adipose tissue dECM was thermo-sensitive biomaterial and underwent a sol-gel phase transition when temperature rises. The dECM-GelMA-HAMA precursor undergoes a gel-sol phase transition at 17.5°C, where the storage and loss modulus of the precursor is about 8 Pa. The scanning electron microscope showed that the interior of crosslinked dECM-GelMA-HAMA hydrogel is 3D porous network structure with suitable porosity and pore size. The shape of the skin substitute is stable with regular grid-like scaffold structure. Wound healing in the experimented animals was accelerated after being treated with 3D-printed skin substitute, which attenuate inflammatory response, increase blood perfusion around the wound, as well as promote re-epithelialization, collagen deposition and alignment, and angiogenesis. In summary, 3D-printed dECM-GelMA-HAMA tissue-engineered skin substitute loaded with hADSCs, which can be fabricated by 3D printing, can accelerate wound healing and improve healing quality by promoting angiogenesis. The hADSCs and the stable 3D-printed stereoscopic grid-like scaffold structure play a critical role in promoting wound healing.

Splint-free line drawing model: An innovative method for excisional wound models.

The physiological phenomenon of wound contraction in mice cannot completely imitate the process of human skin regeneration, which is primarily attributed to reepithelialisation. As such, excisional wound models in mice are considered to be imperfect comparisons. This study aimed to enhance the correlation of mouse excisional wound models with that of humans, and to offer more practical and accurate ways to record and measure wound areas. We present evidence that simple excisional wounds produce a robust and stable wound model by comparing splint-free and splint groups. We monitored reepithelialisation and contraction in the C57BL/6J mouse excision wound model at different time points and prove that excisional wounds heal by both contraction and reepithelialisation. Some parameters were measured and a formula was used to calculate the area of wound reepithelialisation and contraction. In our results, reepithelialisation accounted for 46% of the wound closure of full-thickness excisional wounds. In conclusion, excisional wound models can be used as wound-healing models and a straightforward formula may be used to determine the process of reepithelialisation over a wound bed created by a simple excisional rodent wound model.

CCN1 secreted by human adipose-derived stem cells enhances wound healing and promotes angiogenesis through activating the AKT signalling pathway.

The study aimed to explore the role of cellular communication network factor 1 (CCN1) an extracellular matrix protein in hADSC-treated wound healing. Immunofluorescence and enzyme-linked immunosorbent assays (ELISA) were used to demonstrate the secretion of CCN1 by hADSCs, isolated from human fat tissue. We investigated the role of CCN1 in wound healing by knockdown of CCN1 expression in hADSCs using CCN1 siRNA. Conditioned medium of hADSCs or hADSCs with CCN1 knocked down (hADSC-CMCCN1↓ ) was collected. After treatment with plain DMEM/F12, hADSC-CM, hADSC-CMCCN1↓ , or recombinant human CCN1 (rhCCN1), the wound healing abilities of human umbilical vascular endothelial cells (HUVECs) were assayed, and the AKT, also known as protein kinase B (PKB), signalling pathway was detected using western blotting. Next, we created full-thickness skin wounds on the backs of the mice and different treatments were applied to the wound surface. Wound size was measured using a digital camera on days 0-10, and evaluated. H&E and immunohistochemical staining were performed, and laser Doppler perfusion imaging was used to evaluate blood perfusion. The wound model and wound-healing assay showed that the hADSCs-CM and rhCCN1 groups had enhanced wound healing compared to the hADSCs-CMCCN1↓ group. Further, CCN1 and hADSCs-CM promoted the proliferation and migration of HUVECs through the AKT signalling pathway. We concluded that CCN1 secreted by hADSCs enhances wound healing and promotes angiogenesis by activating the AKT signalling pathway. CCN1 plays a vital role in the regulation of hADSCs-CM during wound healing.

Fibrinogen improves liver function via promoting cell aggregation and fibronectin assembly in hepatic spheroids.

Many key functions performed by the liver depend on the interaction between parenchymal cells and the microenvironment comprised of neighboring cells and extracellular matrix. The biological macromolecules in the matrix, which are dynamically changing, participate in various physiological processes through interactions with cell surface receptors, antigens, and ion channels. We found the rat liver biomatrix scaffold (LBS) prepared from adult rats is more effective in enhancing the function of hepatic spheroids than those derived from newborn or senile rats. Combined with matrisome and bioinformatics analyses, we further found that the glycoproteins, fibronectin and fibrinogen may have special potential for improving hepatocyte function. Human primary hepatocyte organoids and HepaRG spheroids showed more mature hepatocyte phenotype after adding fibronectin and fibrinogen to the culture system. During the cultivation of hepatic spheroids, fibrinogen resulted in an increase in cell-cell junction by promoting cell aggregation and helping fibronectin to assemble on cell surface, which resulted in activation of Wnt/ß-catenin pathway. Fibronectin-integrin αVß1-Wnt/ß-catenin may be the axis of signal transduction in parenchymal cell microenvironment. Importantly, fibrinogen enhances the signal transduction. These results suggest that the addition of fibronectin and fibrinogen to the 3D culture system is a new strategy for inducing parenchymal cell functional maturation.

Comprehensive proteomic atlas of skin biomatrix scaffolds reveals a supportive microenvironment for epidermal development.

Biomaterial scaffolds are increasingly being used to drive tissue regeneration. The limited success so far in human tissues rebuilding and therapy application may be due to inadequacy of the functionality biomaterial scaffold. We developed a new decellularized method to obtain complete anatomical skin biomatrix scaffold in situ with extracellular matrix (ECM) architecture preserved, in this study. We described a skin scaffold map by integrated proteomics and systematically analyzed the interaction between ECM proteins and epidermal cells in skin microenvironment on this basis. They were used to quantify structure and function of the skin's Matrisome, comprised of core ECM components and ECM-associated soluble signals that are key regulators of epidermal development. We especially revealed that ECM played a role in determining the fate of epidermal stem cells through hemidesmosome components. These concepts not only bring us a new understanding of the role of the skin ECM niche, they also provide an attractive combinational strategy based on tissue engineering principles with skin biomatrix scaffold materials for the acceleration and enhancement of tissue regeneration.

ECMPride: prediction of human extracellular matrix proteins based on the ideal dataset using hybrid features with domain evidence.

Extracellular matrix (ECM) proteins play an essential role in various biological processes in multicellular organisms, and their abnormal regulation can lead to many diseases. For large-scale ECM protein identification, especially through proteomic-based techniques, a theoretical reference database of ECM proteins is required. In this study, based on the experimentally verified ECM datasets and by the integration of protein domain features and a machine learning model, we developed ECMPride, a flexible and scalable tool for predicting ECM proteins. ECMPride achieved excellent performance in predicting ECM proteins, with appropriate balanced accuracy and sensitivity, and the performance of ECMPride was shown to be superior to the previously developed tool. A new theoretical dataset of human ECM components was also established by applying ECMPride to all human entries in the SwissProt database, containing a significant number of putative ECM proteins as well as the abundant biological annotations. This dataset might serve as a valuable reference resource for ECM protein identification.

A systems biology approach for defining the potential molecular framework of idiopathic hypereosinophilic syndrome with cutaneous involvement.

Hypereosinophilic syndrome (HES) is a rare multisystem disease that predominantly includes skin with severe and persistent itching. A lack of understanding about the pathological condition and mechanism of dermatosis caused by HES hinders its treatment. In the present study, we applied a quantitative proteomics approach to characterize the cellular responses of skin tissue to idiopathic HES (IHES) at the proteome level. We identified hundreds of skin tissue proteins that were differentially expressed between IHES patients and healthy individuals. IHES patients display severely damaged microenvironment, including extracellular matrix (ECM) organization and disassembly, immune disorders, decreased metabolic capacity, and susceptibility to microbial infection. Moreover, there was abnormal proliferation of basal epidermal stem cells, which was closely related to high expression of the epigenetic regulator, histone deacetylase 2, providing mechanistic insight into the abnormal epidermal thickening of IHES skin tissues. Overall, our study provides a comprehensive framework for a system-level understanding of IHES-induced dermatosis (IHESiD) tissues at the protein and cell pathway levels. Our findings may facilitate a new approach to diagnosis and treatment to alleviate skin clinical symptoms, monitor the activity of IHES, and determine therapeutic effects.