A Comprehensive Review of Natural Compounds for Wound Healing: Targeting Bioactivity Perspective.

Wound healing is a recovering process of damaged tissues by replacing dysfunctional injured cellular structures. Natural compounds for wound treatment have been widely used for centuries. Numerous published works provided reviews of natural compounds for wound healing applications, which separated the approaches based on different categories such as characteristics, bioactivities, and modes of action. However, current studies provide reviews of natural compounds that originated from only plants or animals. In this work, we provide a comprehensive review of natural compounds sourced from both plants and animals that target the different bioactivities of healing to promote wound resolution. The compounds were classified into four main groups (i.e., anti-inflammation, anti-oxidant, anti-bacterial, and collagen promotion), mostly studied in current literature from 1992 to 2022. Those compounds are listed in tables for readers to search for their origin, bioactivity, and targeting phases in wound healing. We also reviewed the trend in using natural compounds for wound healing.

Supercritical Carbon Dioxide Decellularization of Porcine Nerve Matrix for Regenerative Medicine.

Tissue engineering scaffolds are often made from the decellularization of tissues. The decellularization of tissues caused by prolonged contact with aqueous detergents might harm the microstructure and leave cytotoxic residues. In this research, we developed a new technique to use supercritical carbon dioxide (Sc-CO2)-based decellularization for porcine nerve tissue. The effect of decellularization was analyzed by histological examination, including Hematoxylin and Eosin, Masson's Trichrome staining, and 4',6-diamidino-2-phenylindole staining. Moreover, biochemical analysis of the decellularized tissues was also performed by measuring DNA content, amount of collagen, and glycosaminoglycans (GAGs) after decellularization. The results showed that the tissue structure was preserved, cells were removed, and the essential components of extracellular matrix, such as collagen fibers, elastin fibers, and GAG fibers, remained after decellularization. In addition, the DNA content was decreased compared with native tissue, and the concentration of collagen and GAGs in the decellularized nerve tissue was the same as in native tissue. The in vivo experiment in the rat model showed that after 6 months of decellularized nerve implantation, the sciatic function index was confirmed to recover in decellularized nerve. Morphological analysis displayed a range of infiltrated cells in the decellularized nerve, similar to that in native tissue, and the number of Schwann cells that play essential for motor function and sensory in the decellularized nerve was confirmed. These findings indicate that tissue decellularization using Sc-CO2 has been successfully used in tissue engineering.

Zirconium-Based Metal-Organic Framework Capable of Binding Proinflammatory Mediators in Hydrogel Form Promotes Wound Healing Process through a Multiscale Adsorption Mechanism.

The regulation of proinflammatory mediators has been explored to promote natural healing without abnormal inflammation or autoimmune response induced by their overproduction. However, most efforts to control these mediators have relied on pharmacological substances that are directly engaged in biological cycles. It is believed that functional porous materials removing target mediators provide a new way to promote the healing process using their adsorption mechanisms. In this study, the Zr-based metal-organic frameworks (MOF)-808 (Zr6 O4 (OH)4 (BTC)2 (HCOO)6 ) crystals are found to be effective at removing proinflammatory mediators, such as nitric oxide (NO), cytokines, and reactive oxygen species (ROS) in vitro and in vivo, because of their porous structure and surface affinity. The MOF-808 crystals are applied to an in vivo skin wound model as a hydrogel dispersion. Hydrogel containing 0.2 wt% MOF-808 crystals shows significant improvement in terms of wound healing efficacy and quality over the corresponding control. It is also proven that the mode of action is to remove the proinflammatory mediators in vivo. Moreover, the application of MOF-808-containing hydrogels promotes cell activation, proliferation and inhibits chronic inflammation, leading to increased wound healing quality. These findings suggest that Zr-based MOFs may be a promising drug-free solution for skin problems related to proinflammatory mediators.

Development of predictive models for lymphedema by using blood tests and therapy data.

Lymphedema is a disease that refers to tissue swelling caused by an accumulation of protein-rich fluid that is usually drained through the lymphatic system. Detection of lymphedema is often based on expensive diagnoses such as bioimpedance spectroscopy, shear wave elastography, computed tomography, etc. In current machine learning models for lymphedema prediction, reliance on observable symptoms reported by patients introduces the possibility of errors in patient-input data. Moreover, these symptoms are often absent during the initial stages of lymphedema, creating challenges in its early detection. Identifying lymphedema before these observable symptoms manifest would greatly benefit patients by potentially minimizing the discomfort caused by these symptoms. In this study, we propose to use new data, such as complete blood count, serum, and therapy data, to develop predictive models for lymphedema. This approach aims to compensate for the limitations of using only observable symptoms data. We collected data from 2137 patients, including 356 patients with lymphedema and 1781 patients without lymphedema, with the lymphedema status of each patient confirmed by clinicians. The data for each patient included: (1) a complete blood count (CBC) test, (2) a serum test, and (3) therapy information. We used various machine learning algorithms (i.e. random forest, gradient boosting, decision tree, logistic regression, and artificial neural network) to develop predictive models on the training dataset (i.e. 80% of the data) and evaluated the models on the external validation dataset (i.e. 20% of the data). After selecting the best predictive models, we created a web application to aid medical doctors and clinicians in the rapid screening of lymphedema patients. A dataset of 2137 patients was assembled from Seoul National University Bundang Hospital. Predictive models based on the random forest algorithm exhibited satisfactory performance (balanced accuracy = 87.0 ± 0.7%, sensitivity = 84.3 ± 0.6%, specificity = 89.1 ± 1.5%, precision = 97.4 ± 0.7%, F1 score = 90.4 ± 0.4%, and AUC = 0.931 ± 0.007). We developed a web application to facilitate the swift screening of lymphedema among medical practitioners: https://snubhtxt.shinyapps.io/SNUBH_Lymphedema . Our study introduces a novel tool for the early detection of lymphedema and establishes the foundation for future investigations into predicting different stages of the condition.

Enhancement of Wound Healing Efficacy by Chitosan-based Hydrocolloid on Sprague Dawley Rats.

BACKGROUND/AIM: Chitosan-based functional materials have attracted considerable attention worldwide for applications in wound healing, especially in skin wound healing, due to their efficiency in hemostasis, anti-bacterial, and skin regeneration. Various chitosan-based products have been developed for skin wound healing applications, but most of these face limitations in either efficacy or cost-effectiveness. Therefore, there is a need to develop a unique material that can handle all of these concerns and be utilized for acute and chronic wounds. This study investigated mechanisms of new chitosan-based hydrocolloid patches in inflammatory reduction and skin formation by using wound-induced Sprague Dawley Rats. MATERIALS AND METHODS: Our study combined a hydrocolloid patch with chitosan to achieve a practical and accessible medical patch that would enhance skin wound healing. Our chitosan-embedded patch has shown a significant influence by preventing wound expansion and inflammation increment on Sprague Dawley rat models. RESULTS: The chitosan patch significantly increased the wound healing rate and accelerated the inflammatory stage by suppressing pro-inflammatory cytokines activity (e.g., TNF-α, IL-6, MCP-1, and IL-1ß). Moreover, the product was effective in promoting skin regeneration, demonstrated by the increase in the number of fibroblasts through specific biomarkers (e.g., vimentin, α-SMA, Ki-67, collagen I, and TGF-ß1). CONCLUSION: Our study on the chitosan-based hydrocolloid patches not only elucidated mechanisms of reducing inflammation and enhancing proliferation, but also provided a cost-effective method for skin wound dressing.

Comparison of Formation of Capsule Among Different Breast Silicone Implants.

BACKGROUND/AIM: Silicone implants are widely used biomaterials in surgeries owing to their physiological inertness and low toxicity. However, capsular contracture is a severe complication caused by the insertion of breast implants, which can endanger the health of patients. In this study, twelve different silicone breast implants were tested to determine which could lead to a lower incidence of capsular contracture. MATERIALS AND METHODS: For in vivo experiments, these silicone implants were implanted into 60 rats (i.e., five implants per rat). The implants were explanted eight weeks after the operation. Samples were analyzed and measured by using hematoxylin and eosin staining, Masson's trichrome staining, and immunofluorescence staining methods. We compared twelve samples for their differences in the thickness of capsular formation, number of inflammatory cells, collagen expression, fibroblast intensity (i.e., Vimentin and α-SMA), and inflammatory cytokines (i.e., IL-8, CD68, MCP-1, and F4/80). RESULTS: Different surface textures of breast implants gave different effects on capsular thickness, collagen formation, fibroblast formation, and potential inflammation. Samples that had smooth textures such as SEBBIN, HANS, and Mentor showed higher collagen formation than other samples. SEBBIN Texture, Motiva Micro, HANS Smooth I, and HANS Micro exhibited higher fibroblast formation (i.e., α-SMA, Vimentin). SEBBIN Smooth and samples in HANS group displayed lower expression of inflammation cytokines (IL-8, CD68, MCP-1, and F4/80). CONCLUSION: These findings provide preliminary reports on the surface texture effect and support a selection of breast silicone implants in breast reconstruction to avoid the formation of capsular contracture after implantation.

Effective decellularization of human skin tissue for regenerative medicine by supercritical carbon dioxide technique.

Allotransplantation, performed using an acellular dermal matrix (ADM), plays a significant role in the cultivation of constituted and damaged organs in clinical. Herein, we fabricated an innovative ADM for allografting derived from decellularized human skin by utilizing the supercritical fluid of carbon dioxide to eliminate immunogenic components. By using histological staining, the ADM product demonstrated the successful removal of cellular constituents without exerting any harmful influence on the extracellular matrix. The results from DNA electrophoresis also supported this phenomenon by showing the complete DNA removal in the product, accompanied by the absence of Major Histocompatibility Complex 1, which suggested the supercritical fluid is an effective method for cellular withdrawal. Moreover, the mechanical property of the ADM products, which showed similarity to that of native skin, displayed great compatibility for using our human-derived ADM as an allograft in clinical treatment. Specifically, the cell viability demonstrated the remarkable biocompatibility of the product to human bio-cellular environment which was noticeably higher than that of other products. Additionally, the significant increase in the level of growth factors such as vascular endothelial growth factor, urokinase-type plasminogen activator receptor, granulocyte-macrophage colony-stimulating factor suggested the ability to stimulate cellular processes, proving the products to be innovative in the field of regeneration when applied to clinical in the future. This study provides a thoroughly extensive analysis of the new ADM products, enabling them to be applied in industrial and clinical treatment.