Skin Scaffolds Research Articles

Evaluation of 3D bioprinted skin scaffolds in mice along with gold nanoparticles exposure

Evaluation of 3D bioprinted skin scaffolds in mice along with gold nanoparticles exposure

Dual optical elastography detects -induced alterations in the biomechanical properties of skin scaffolds.

The skin's mechanical properties are tightly regulated. Various pathologies can affect skin stiffness, and understanding these changes is a focus in tissue engineering. Ex vivo skin scaffolds are a robust platform for evaluating the effects of various genetic and molecular interactions on the skin. Transforming growth factor-beta ( ) is a critical signaling molecule in the skin that can regulate the amount of collagen and elastin in the skin and, consequently, its mechanical properties. This study investigates the biomechanical properties of bio-engineered skin scaffolds, focusing on the influence of , a signaling molecule with diverse cellular functions. The receptor I inhibitor, galunisertib, was employed to assess the mechanical changes resulting from dysregulation of . Skin scaffold samples, grouped into three categories (control, -treated, and + galunisertib-treated), were prepared in two distinct culture media-one with aprotinin (AP) and another without. Two optical elastography techniques, namely wave-based optical coherence elastography (OCE) and Brillouin microscopy, were utilized to quantify the biomechanical properties of the tissues. Results showed significantly higher wave speed (with AP, ; without AP, ) and Brillouin frequency shift (with AP, ; without AP, ) in -treated group compared with the control group. The difference in wave speed between the control and + galunisertib with ( ) and without AP ( ) was not significant. Moreover, the + galunisertib-treated group exhibited lower wave speed without and with AP and reduced Brillouin frequency shift than the -treated group without AP, further strengthening the potential role of in regulating the mechanical properties of the samples. These findings offer valuable insights into -induced biomechanical alterations in bio-engineered skin scaffolds, highlighting the potential of OCE and Brillouin microscopy in the development of targeted therapies in conditions involving abnormal tissue remodeling and fibrosis.

Bioinspired Collagen Scaffold Loaded with bFGF-Overexpressing Human Mesenchymal Stromal Cells Accelerating Diabetic Skin Wound Healing via HIF-1 Signal Pathway Regulated Neovascularization.

The healing of severe chronic skin wounds in chronic diabetic patients is still a huge clinical challenge due to complex regeneration processes and control signals. Therefore, a single approach is difficult in obtaining satisfactory therapeutic efficacy for severe diabetic skin wounds. In this study, we adopted a composite strategy for diabetic skin wound healing. First, we fabricated a collagen-based biomimetic skin scaffold. The human basic fibroblast growth factor (bFGF) gene was electrically transduced into human umbilical cord mesenchymal stromal cells (UC-MSCs), and the stable bFGF-overexpressing UC-MSCs (bFGF-MSCs) clones were screened out. Then, an inspired collagen scaffold loaded with bFGF-MSCs was applied to treat full-thickness skin incision wounds in a streptozotocin-induced diabetic rat model. The mechanism of skin damage repair in diabetes mellitus was investigated using RNA-Seq and Western blot assays. The bioinspired collagen scaffold demonstrated good biocompatibility for skin-regeneration-associated cells such as human fibroblast (HFs) and endothelial cells (ECs). The bioinspired collagen scaffold loaded with bFGF-MSCs accelerated the diabetic full-thickness incision wound healing including cell proliferation enhancement, collagen deposition, and re-epithelialization, compared with other treatments. We also showed that the inspired skin scaffold could enhance the in vitro tube formation of ECs and the early angiogenesis process of the wound tissue in vivo. Further findings revealed enhanced angiogenic potential in ECs stimulated by bFGF-MSCs, evidenced by increased AKT phosphorylation and elevated HIF-1α and HIF-1β levels, indicating the activation of HIF-1 pathways in diabetic wound healing. Based on the superior biocompatibility and bioactivity, the novel bioinspired skin healing materials composed of the collagen scaffold and bFGF-MSCs will be promising for healing diabetic skin wounds and even other refractory tissue regenerations. The bioinspired collagen scaffold loaded with bFGF-MSCs could accelerate diabetic wound healing via neovascularization by activating HIF-1 pathways.

Advances in veterinary ophthalmology: Acellular protein matrix from tilapia skin (Oreochromis Niloticus) in the recovery of corneal ulcers in dogs and cats

The acellular protein matrix from tilapia skin has excellent biomechanical properties, lack of immunogenicity and high biocompatibility in vitro and in vivo. Therefore, it provides an environment conducive to cell regeneration, specifically in more invasive and delicate applications, such as the recovery of corneal ulcers in dogs and cats. The objective of this literature review is to present the use of the scaffold as a new approach in veterinary ophthalmology in the treatment of corneal injuries in relation to conventional methods. When applied to corneal ulcers, the biomaterial acts as a tissue scaffold, facilitating cell migration, promoting angiogenesis and minimizing the inflammatory response; thus, significantly accelerating the healing process. It also improves corneal transparency, reduces recovery time and reduces post-treatment complications. Clinical trials involving dogs and cats have had significant success, demonstrating the applicability and effectiveness of this innovation in the context of veterinary ophthalmology. This study highlights both the effectiveness of the tilapia skin scaffold and emphasizes its potential to transform clinical practice by providing a sustainable, affordable and pioneering approach to treating corneal ulcers in small animals.

Preparation of silk fibroin-derived hydrogels and applications in skin regeneration.

To compare different methods of preparing silk fibroin hydrogels, then summarize the applications of silk fibroin hydrogel-based scaffolds in skin regeneration and finally discuss about future prospects to inspire people interested in this field. A narrative review of the relevant papers was conducted. Notably, for applications in skin regeneration, this review provides a categorized summary and discussion of studies from the past decade. Silk fibroin is a naturally occurring, biocompatible biomaterial that is easily producible. Thanks to its exceptional processability, silk fibroin has found diverse applications in skin regeneration. These applications encompass sponges, fiber fabrics, thin films, and hydrogels. Hydrogels, in particular, are noteworthy due to their water-containing network structure, closely resembling natural tissues. They provide a biomimetic three-dimensional growth environment for cells and have the capacity to incorporate growth factors. Consequently, there are abundant studies of silk fibroin hydrogel-based scaffolds in skin regeneration. Besides, some commercialized medical devices are also made of silk fibroin. Silk fibroin hydrogel could be prepared with multiple methods and it is widely used in constructing scaffolds for efficient skin regeneration. In the future, silk fibroin hydrogel-based skin scaffolds could be more biomimetic and smart.

Multi-variate multi-objective optimization of production conditions for electro-spun skin scaffold using RSM and investigation of gamma irradiation effects on the properties of the optimized sample

Developing electro-spun scaffolds with ideal mechanical properties for skin purposes can profit from using the Response Surface Methodology technique to define and optimize the outcome quality and required sterilization for use in vivo. This study investigated the effects of four main independent electrospinning variables for polycaprolactone nanofibers scaffold using multi-variable and multi-objective optimization. It was done to determine significant parameters on responses and find optimal conditions to reach the preferred properties. Young's modulus, elongation-at-break, and tensile strength were the responses. After obtaining appropriate models, the impact share of variables on the responses was determined using Sobol sensitivity analysis. The results showed that flow rate is the most significant parameter of elastic modulus and tensile strength responses, with 76.45 % and 41.27 % impact shares, respectively. The polymer concentration is the following significant parameter on elongation at break, tensile strength and, Young's modulus responses with 64.35 %, 39.485 and, 14.28 % impact share, respectively. Based on the optimized results, a skin scaffold with desired mechanical properties was achieved (under solution concentration of 10 % w/v, flow rate of 2 mL/h, nuzzle-collector distance of 15 cm, and applied voltage of 20 kV). Then it was sterilized with gamma radiation of various doses (25, 40, and 55 kGy) to use in vivo. The SEM analysis indicated no significant change in fibrous morphology due to gamma irradiation at any dosage. FTIR analysis demonstrated the breakup of ester bonds due to gamma irradiation. For samples irradiated by 25 kGy, the crystallinity percentage decreased and chains crosslinking without losing the mechanical stability was dominant. The studies demonstrated that 25 kGy of gamma irradiation could improve the mechanical properties of the optimized PCL skin scaffold, which is very promising for wound healing.

Porous gradient hydrogel promotes skin regeneration by angiogenesis

The skin has a multilayered structure, and deep-seated injuries are exposed to external microbial invasion and in vivo microenvironmental destabilization. Here, a bilayer bionic skin scaffold (Bilayer SF) was developed based on methacrylated sericin protein to mimic the skin’s multilayered structure and corresponding functions. The outer layer (SF@TA), which mimics the epidermal layer, was endowed with the function of resisting external bacterial and microbial invasion using a small pore structure and bio-crosslinking with tannic acid (TA). The inner layer (SF@DA@Gel), which mimics the dermal layer, was used to promote cellular growth using a large pore structure and introducing dopamine (DA) to regulate the wound microenvironment. This Bilayer SF showed good mechanical properties and structural stability, satisfactory antioxidant and promote cell proliferation and migration abilities. In vitro studies confirmed the antimicrobial properties of the outer layer and the pro-angiogenic ability of the inner layer. In vivo animal studies demonstrated that the bilayer scaffolds promoted collagen deposition, neovascularization, and marginal hair follicle formation, which might be a promising new bionic skin scaffold.

Developing a gel-col heterogeneous network hydrogel scaffold for tissue-engineered skin with enhanced basement membrane formation

Tissue-engineered skin is constructed utilizing biocompatible matrix materials as scaffolds, and incorporating human epidermal keratinocytes (HEKs), dermal fibroblasts (HDFs), and bioactive molecules, addressing clinical issues such as skin graft rejection and donor scarcity. Conventional fabrication methods of tissue-engineered skin typically rely on homogeneous single-network scaffolds, which may not adequately address the distinct requirements of epidermal and dermal cells or the critical formation of the basement membrane, potentially impacting the development and functional integrity of the skin tissue. Cell culture studies employing GelMA hydrogels of varied concentrations have elucidated that epidermal cells exhibit increased viability on scaffolds with higher concentrations (15 %), whereas fibroblasts show increased proliferation within scaffolds of lower concentrations (5 %). Consequently, we have engineered a GelMA-collagen (Gel-Col) hydrogel scaffold with a heterogeneous network of dense and sparse matrices, conducive to the growth of both fibroblasts and epidermal cells. Culturing epidermal cells on this innovative scaffold, coupled with histological section staining, RT-PCR, and Western blot analyses, has demonstrated that the scaffold significantly enhances cellular adhesion and promotes the development of the epidermal basement membrane compared to single-network hydrogels. Mouse wound transplantation experiments have further confirmed the scaffold’s effectiveness in accelerating wound repair, supporting the development of the basement membrane, and enhancing epidermal regeneration. This research provides a reference for constructing tissue-engineered skin that more precisely emulates the intricate architecture and cellular dynamics of natural skin, propelling the advancement of tissue-engineered skin grafts in the clinical treatment of skin injuries.

Fibroblasts/three-dimensional scaffolds complexes promote wound healing in rats with skin defects

ABSTRACT We aim to construct a three-dimensional nano-skin scaffold material in vitro and study its promoting effect on wound healing in vivo. In this study, hybrid constructs of three-dimensional (3D) scaffolds were successfully fabricated by combination of type I collagen (COL-1) and polylactic-glycolic acid (PLGA). Fibroblasts and human umbilical cord mesenchymal stem cells (hUCMSCs) were used to implanted into 3D scaffolds and constructed into SD skin scaffolds in vitro. Finally, the fibroblasts/scaffolds complexes were inoculated on the surface of rat wound skin to study the promoting effect of the complex on wound healing. In our study, we successfully built a 3D scaffold, which had a certain porosity. Meanwhile, the content of COL-1 in the cell supernatant of fibroblast/scaffold complexes was increased. Furthermore, the expression of F-actin, CD105, integrin β, VEGF, and COL-1 was up-regulated in hUCMSC/scaffold complexes compared with the control group. In vivo, fibroblast/scaffold complexes promoted wound healing in rats. Our data suggested that the collagen Ⅳ and vimentin were elevated and collagen fibers were neatly arranged in the fibroblast/scaffold complex group was significantly higher than that in the scaffold group. Taken together, fibroblast/scaffold complexes were expected to be novel materials for treating skin defects.

Carboxymethyl cellulose-agarose hydrogel in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nanofibers: A novel tissue engineered skin graft

Healing chronic and critical-sized full-thickness wounds is a major challenge in the healthcare sector. Scaffolds prepared using electrospinning and hydrogels serve as effective treatment options for wound healing by mimicking the native skin microenvironment. Combining synthetic nanofibers with tunable hydrogel properties can effectively overcome limitations in skin scaffolds made only with nanofibers or hydrogels. In this study, a biocompatible hybrid scaffold was developed for wound healing applications using poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers embedded with hydrogel made of 2 % carboxymethyl cellulose (CMC) blended with 1 % agarose. Hybrid scaffolds, characterized for surface morphology, swellability, porosity, and degradation, were found to be suitable for wound healing. Furthermore, the incorporation of CMC-agarose hydrogel into nanofibers significantly enhanced their mechanical strength compared to PHBV nanofibers alone (p < 0.05). Extract cytotoxicity and direct cytotoxicity tests showed that the hybrid scaffolds developed in this study are cytocompatible (>75 % viability). Furthermore, human adult dermal fibroblasts (HDFa) and human adult immortalized keratinocytes (HaCaT) adhesion, viability, and proliferation studies revealed that the hybrid scaffolds exhibited a significant increase in cell proliferation over time, similar to PHBV nanofibers. Finally, the developed hybrid scaffolds were evaluated in rat full-thickness wounds, demonstrating their ability to promote full-thickness wound healing with reepithelialization and epidermis closure.

Enhancement of Wound Healing and Angiogenesis Using Mouse Embryo Fibroblasts Loaded in Decellularized Skin Scaffold.

Synthetic and natural polymer scaffolds can be used to design wound dressing for repairing the damaged skin tissue. This study investigated acute wound healing process using a decellularized skin scaffold and mouse embryo fibroblast (MEF). Mouse skin fragments were decellularized and evaluated by DNA content, toxicity, H&E staining, Raman confocal microscopy, Masson’s trichrome staining, SEM, and biodegradation assays. The fragments were recellularized by the MEFs, and cell attachment and penetration were studied. De- and decellularized scaffolds were used wound dressings in mouse acute wound models as two experimental groups. Using morphological and immunohistochemical assessments, wound healing was evaluated and compared among the experimental and control groups. DNA content of the decellularized tissue significantly reduced compared to the native control group (7% vs. 100%; p < 0.05). extracellular matrix components, e.g. collagen types I, III, and IV, elastin, and glycosaminoglycan, were well preserved in the decellularized group. The porosity and fiber arrangement in the stroma had a structure similar to normal skin tissue. A significant reduction in healing time was observed in the group treated with a decellularized scaffold. A thicker epidermis layer was observed in the recovered tissue in both experimental groups compared to the control group. Immunostaining showed a positive reaction for CD31 as an endothelial marker in both experimental groups, confirming new vascularization in these groups. Using MEFs with decellularized skin as a wound dressing increases the rate of wound healing and also the formation of new capillaries. This system could be beneficial for clinical applications in the field of tissue engineering.

Versatile Bioactive Glass/Zeolitic Imidazolate Framework-8-Based Skin Scaffolds toward High-Performance Wound Healing.

Designing a novel biomaterial for wound healing is based on biocompatibility and excellent mechanical strength. In this study, bioactive glass (BG) and zeolitic imidazolate framework-8 (ZIF-8) have been incorporated into poly(ε-caprolactone)/poly(vinyl alcohol) (PCL/PVA) composite skin scaffolds via microfluidic electrospinning. Interestingly, the addition of ZIF-8 further strengthens the BG stability and demonstrates better antibacterial effects. Utilizing the slow release of Zn, Ca, and Si ions, it also significantly promotes growth factor expression and skin regeneration. In addition, it is further demonstrated by in vitro and in vivo studies that the prepared composite skin scaffolds possess excellent biocompatibility, antibacterial capabilities, and mechanical properties. The prepared BG/ZIF-8-loaded scaffold possesses high tensile strength (26 MPa) and excellent antibacterial properties (achieves 89.64 and 78.8% inhibition of E. coli and S. aureus, respectively), and cell viability increased by 51.2%. More importantly, the wound shrinkage of the BG/ZIF-8-loaded scaffold is better than that of an unloaded scaffold, and the shrinkage rates of PCL/PVA@BG/ZIF-8(1 wt %) group is 95% with 2.2 mm granulation growth thickness within 12 days. Thus, the composite skin scaffold loaded with BG/ZIF-8 prepared by microfluidic electrospinning provides a new perspective for accelerating wound healing and is a potential novel therapeutic strategy for efficient wound healing.

3D bioprinting of Salvianolic acid B-sodium alginate-gelatin skin scaffolds promotes diabetic wound repair via antioxidant, anti-inflammatory, and proangiogenic effects

In patients with diabetic wounds, wound healing is impaired due to the presence of persistent oxidative stress, an altered inflammatory response, and impaired angiogenesis and epithelization. Salvianolic acid B (SAB), which is derived from the Chinese medicinal plant Salvia miltiorrhiza, has been found to exhibit antioxidant, anti-inflammatory, and proangiogenic effects. Previous studies have used 3D bioprinting technology incorporating sodium alginate (SA) and gelatin (Gel) as basic biomaterials to successfully produce artificial skin. In the current study, 3D bioprinting technology was used to incorporate SAB into SA-Gel to form a novel SAB-SA-Gel composite porous scaffold. The morphological characteristics, physicochemical characteristics, biocompatibility, and SAB release profile of the SAB-SA-Gel scaffolds were evaluated in vitro. In addition, the antioxidant, anti-inflammatory, and proangiogenic abilities of the SAB-SA-Gel scaffolds were evaluated in cells and in a rat model. Analysis demonstrated that 1.0 wt% (the percentage of SAB in the total weight of the solution containing SA and Gel) SAB-SA-Gel scaffolds had strong antioxidant, anti-inflammatory, and proangiogenic properties both in cells and in the rat model. The 1.0% SAB-SA-Gel scaffold reduced the expression of tumor necrosis factor-α, interleukin-6, and interluekin-1β and increased the expression of transforming growth factor-β. In addition, this scaffold removed excessive reactive oxygen species by increasing the expression of superoxide dismutase, thereby protecting fibroblasts from injury. The scaffold increased the expression of vascular endothelial growth factor and platelet/endothelial cell adhesion molecule-1, accelerated granulation tissue regeneration and collagen deposition, and promoted wound healing. These findings suggest that this innovative scaffold may have promise as a simple and efficient approach to managing diabetic wound repair.

A decellularized matrix enriched collagen microscaffold for a 3D in vitro liver model.

The development of liver scaffolds retaining their three-dimensional (3D) structure and extra-cellular matrix (ECM) composition is essential for the advancement of liver tissue engineering. We report the design and validation of an alginate-based platform using a combination of decellularized matrices and collagen to preserve the functionality of liver cells. The scaffolds were characterized using SEM and fluorescence microscopy techniques. The proliferation and functional behaviours of hepatocellular carcinoma HuH7 cells were observed. It was found that the decellularized skin scaffold with collagen was better for maintaining the growth of cells in comparison to other decellularized matrices. In addition, we observed a significant increase in the functional profile once exogenous collagen was added to the liver matrix. Our study also suggests that a cirrhotic liver model should have a different matrix composition as compared to a healthy liver model. When primary rat hepatocytes were used for developing a healthy liver model, the proliferation studies with hepatocytes showed a decellularized skin matrix as the better option, but the functionality was only maintained in a decellularized liver matrix with addition of exogenous collagen. We further checked if these platforms can be used for studying drug induced toxicity observed in the liver by studying the activation of cytochrome P450 upon drug exposure of the cells growing in our model. We observed a significant induction of the CYP1A1 gene on administering the drugs for 6 days. Thus, this platform could be used for drug-toxicity screening studies using primary hepatocytes in a short span of time. Being a microscaffold based system, this platform offers some advantages, such as smaller volumes of samples, analysing multiple samples simultaneously and a minimal amount of decellularized matrix in the matrix composition, making it an economical option compared to a completely dECM based platform.

Preparation, design, and characterization of an electrospun polyurethane/calcium chloride nanocomposite scaffold with improved properties for skin tissue regeneration

The present research paper explores the potential of electrospun nanofibers in the promising field of skin tissue engineering. Specifically, we propose an advanced preparation and characterization of an electrospun Polyurethane/Calcium Chloride (PU/CaCl2) nanocomposite scaffold, devised to boost the scaffold’s physicochemical and biological properties for skin tissue regeneration. By incorporating CaCl2 into the PU matrix using an electrospinning process, we were able to fabricate a novel nanocomposite scaffold. The morphological examination through Field Emission Scanning Electron Microscope (FESEM) revealed that the fiber diameter of the PU/CaCl2 (563 ± 147 nm) scaffold was notably smaller compared to the control (784 ± 149 nm). The presence of CaCl2 in the PU matrix was corroborated by Fourier-Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). Furthermore, the PU/CaCl2 scaffold exhibited superior tensile strength (10.81 MPa) over pristine PU (Tensile −6.16 MPa, Contact angle - 109° ± 1° and Roughness - 854 ± 32 nm) and revealed enhanced wettability (72° ± 2°) and reduced surface roughness (274 ± 104 nm), as verified by Contact angle and Atomic Force Microscopy. The developed scaffold demonstrated improved anticoagulant properties, indicating its potential for successful integration within a biological environment. The improved properties of the PU/CaCl2 nanocomposite scaffold present a significant advancement in electrospun polymer nanofibers, offering a potential breakthrough in skin tissue engineering. However, additional studies are required to thoroughly evaluate the scaffold’s effectiveness in promoting cell adhesion, proliferation, and differentiation. We aim to catalyze significant advancements in the field by revealing the creation of a potent skin scaffold leveraging electrospun nanofibers. Encouraging deeper exploration into this innovative electrospun composite scaffold for skin tissue engineering, the PU/CaCl2 scaffold stands as a promising foundation for pioneering more innovative, efficient, and sustainable solutions in biomedical applications.

Enzymatic functionalization of decellularized tilapia skin scaffolds with enhanced skin regeneration.

The decellularized tilapia skin (dTS) has gained significant attention as a promising material for tissue regeneration due to its ability to provide unique structural and functional components that support cell growth, adhesion, and proliferation. However, the clinical application of dTS is limited by its low mechanical strength and rapid biodegradability. Herein, we prepare a novel RGD (arginine-glycine-aspartic acid) functionalized dTS scaffold (dTS/RGD) by using transglutaminase (TGase) crosslinking. The developed dTS/RGD scaffold possesses excellent properties, including a medium porosity of ∼59.2%, a suitable degradation rate of approximately 80% over a period of two weeks, and appropriate mechanical strength with a maximum tensile stress of ∼46.36 MPa which is much higher than that of dTS (∼32.23 MPa). These properties make the dTS/RGD scaffold ideal for promoting cell adhesion and proliferation, thereby accelerating skin wound healing in a full-thickness skin defect model. Such an enzymatic cross-linking strategy provides a favorable microenvironment for wound healing and holds great potential for application in skin regeneration engineering.

Flexible Accelerated-Wound-Healing Antibacterial Hydrogel-Nanofiber Scaffold for Intelligent Wearable Health Monitoring.

Flexible epidermal sensors hold significant potential in personalized healthcare and multifunctional electronic skins. Nonetheless, achieving both robust sensing performance and efficient antibacterial protection, especially in medical paradigms involving electrophysiological signals for wound healing and intelligent health monitoring, remains a substantial challenge. Herein, we introduce a novel flexible accelerated-wound-healing biomaterial based on a hydrogel-nanofiber scaffold (HNFS) via electrostatic spinning and gel cross-linking. We effectively engineer a multifunctional tissue nanoengineered skin scaffold for wound treatment and health monitoring. Key features of HNFS include high tensile strength (24.06 MPa) and elasticity (214.67%), flexibility, biodegradability, and antibacterial properties, enabling assembly into versatile sensors for monitoring human motion and electrophysiological signals. Moreover, in vitro and in vivo experiments demonstrate that HNFS significantly enhances cell proliferation and skin wound healing, provide a comprehensive therapeutic strategy for smart sensing and tissue repair, and guide the development of high-performance "wound healing-health monitoring" bioelectronic skin scaffolds. Therefore, this study provides insights into crafting flexible and repairable skin sensors, holding potential for multifunctional health diagnostics and intelligent medical applications in intelligent wearable health monitoring and next-generation artificial skin fields.

Progress in Research and Application of Modified Silk Fibroin Fibers

AbstractSilk fibroin (SF) is a biodegradable protein and possesses superior skin‐friendliness, biocompatibility, low immunogenicity, and non‐toxicity. However, SF has a series of drawbacks. For example, the application of SF in water filtration is limited by its inadequate ability to adsorb heavy metal ions. It is not inherently antibacterial, making SF ineffective as a filter to eliminate airborne bacteria. SF without conductivity is not suitable for use in sensors and triboelectric nanogenerators. In tissue engineering, deficient mechanical and anti‐inflammatory properties also have an influence on the rate of wound recovery. While physical and chemical modifications will improve its application properties as well as broaden its application areas. This review describes the modification of SF by filling, blending, structural adjustment, post treatment, crosslinking, grafting, and in situ polymerization to provide it with other functional properties. Modified SF fibers prepared by various methods (e.g., wet/dry/microfluidic spinning, electrospinning) are discussed, and they can be used in water/air filtration, chemical/pressure/strain sensors, triboelectric nanogenerators, artificial skin, wound dressings, and tissue scaffolds. Finally, the development trend of the modified SF fibers is prospected. This review has a reference significance on how to use modified SF fibers to improve filtration efficiency, sensor performance, and wound recovery.

Development of a Skin Scaffold for Wound Healing Using a Polymer Blend

Native skin consists mainly of epidermal and dermal layers. Here in this work, we have constructed an artificial skin scaffold mimicking the bilayered structure of the native skin using electrospinning technique for wound healing. Polyurethane (PU) and Gelatin (Ge) were used for developing the epidermal layer and the dermal layer respectively. Ciprofloxacin HCl (Cip. HCl) a fluoroquinolone antibiotic was incorporated in both the layers for rapid wound healing. Morphology of the skin scaffold was studied using scanning electron microscopy (SEM) analysis and the chemical characterization was performed using FTIR spectroscopy. Water vapor transmission rate test and oxygen transmission rate test was conducted to evaluate the barrier properties of the scaffold. Thermal stability of the skin scaffold was evaluated using DSC and TGA while an understanding of the exudate absorbing capacity and degradation behavior of the scaffold was obtained from water absorption studies and in vitro degradation studies respectively. In vitro drug release study and drug release kinetics was explored to understand the release mechanism of Cip. HCl from the scaffold. Both the layers showed nano and micropores when analyzed using SEM. The dermal layer showed comparatively more water absorption capacity and degradation, hence providing a moist environment for the wound. The skin scaffold was permeable to water vapor and oxygen, and hence will speed up the process of wound healing. In vitro release for Cip. HCl showed a non-Fickian swelling type release with zero-order kinetics. Disk diffusion test conducted on the bilayers proved the antibacterial activity of the membrane. Hence the electrospun PU-Ge skin scaffold containing Cip. HCl is a promising candidate among modern day wound healing materials.

Current Status of Auricular Reconstruction Strategy Development.

Microtia has severe physical and psychological impacts on patients, and auricular reconstruction offers improved esthetics and function, alleviating psychological issues. Microtia is a congenital disease caused by a multifactorial interaction of environmental and genetic factors, with complex clinical manifestations. Classification assessment aids in determining treatment strategies. Auricular reconstruction is the primary treatment for severe microtia, focusing on the selection of auricular scaffold materials, the construction of auricular morphology, and skin and soft tissue scaffold coverage. Autologous rib cartilage and synthetic materials are both used as scaffold materials for auricular reconstruction, each with advantages and disadvantages. Methods for achieving skin and soft tissue scaffold coverage have been developed to include nonexpansion and expansion techniques. In recent years, the application of digital auxiliary technology such as finite element analysis has helped optimize surgical outcomes and reduce complications. Tissue-engineered cartilage scaffolds and 3-dimensional bioprinting technology have rapidly advanced in the field of ear reconstruction. This article discusses the prevalence and classification of microtia, the selection of auricular scaffolds, the evolution of surgical methods, and the current applications of digital auxiliary technology in ear reconstruction, with the aim of providing clinical physicians with a reference for individualized ear reconstruction surgery. The focus of this work is on the current applications and challenges of tissue engineering and 3-dimensional bioprinting technology in the field of ear reconstruction, as well as future prospects.