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In vivo proof‐of‐concept of the efficacy of the fibro‐gel. a) Schematic of the mice excision skin model. A full‐thickness circle of skin with a 1 cm diameter was excised. In the control group, the mice were not dressed while in the commercial gel group (Hydrosorb Gel), the fibro‐gel without TC and EGF group, the fibro‐gel with TC and EGF group (A) (same Lfiber), and the fibro‐gel with TC and EGF group (B) (different Lfiber), the mice were dressed with the commercial gel and the corresponding fibro‐gel respectively. In the free TC and EGF group, the mice were treated with 0.85 mg TC and 42.5 ng EGF on day 0. b) Photographs of mice skin wound tissues for different groups on days 0, 4, 8, and 12, showing that the wound site of the fibro‐gel group with TC and EGF in different fiber lengths is substantially reduced. The inner diameter of the rubber ring is 1 cm. c) Measured wound healing rate of different groups for 4, 8, and 12 days, showing the fastest wound healing rates occur with the fibro‐gel with TC and EGF group (B). d) Hematoxylin and eosin (H&E) staining of skin tissue for the control group, the commercial gel group, the free TC and EGF group, the fibro‐gel without TC and EGF group, the fibro‐gel with TC and EGF group (A) on day 12 and the fibro‐gel with TC and EGF group (B) on day 8. In the fibro‐gel with TC and EGF group (B), the magnified images showed the complete epithelium and dermis structures, while in the control group, the free TC and EGF group, and the commercial gel group the regenerated skin tissues displayed the typical appearance of collagenous scar tissue. e) Epidermal thickness of skin tissue for different groups at the end of the experiment for the control group, the commercial gel group, the free TC and EGF group, the fibro‐gel without TC and EGF group, the fibro‐gel with TC and EGF group (A) on day 12 and the fibro‐gel with TC and EGF group (B) on day 8. f) Quantitative analysis of the regenerated tissue thickness for the control group, the commercial gel group, the free TC and EGF group, the fibro‐gel without TC and EGF group, the fibro‐gel with TC and EGF group (A) on day 12 and the fibro‐gel with TC and EGF group (B) on day 8. The recovery of regenerated tissue was evaluated by measuring the thickness of regenerated tissue. Paired t was calculated and values with a p‐value ≤ 0.05 are considered statistically significant. (NS, not significant, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001).
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Injectable hydrogels are valuable tools in tissue engineering and regenerative medicine due to the unique advantages of injectability with minimal invasiveness and usability for irregularly shaped sites. However, it remains challenging to achieve scalable manufacturing together with matching physicochemical properties and on-demand drug release for...
Citations
... [54,55] The remarkable photothermal performance of hydrogels and the inherent antibacterial activity of tannic acid have triggered the interest of the present research group in exploring their antibacterial efficacy. [56][57][58] In this study, two common pathogenic bacteria, Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), were employed to evaluate the antibacterial performance of the hydrogel. ...
The continuously growing utilization of wound healing materials and skin bioelectronics urges the development of flexible hydrogels for personal therapy and health management. Versatile conductive hydrogels prepared from natural biomass are ideal candidates as one of the promising solutions for chronic wound management. Here, the study proposes a kind of robust (strain: 1560.8%), adhesive, self‐healing, injectable, antibacterial (sterilization rate: 99%), near‐infrared (NIR) photothermal responsive, biocompatible, and conductive hydrogel (CPPFe@TA) composed of carboxymethyl cellulose and tannic acid/iron ion complex (TA@Fe³⁺), featuring rapid self‐assembly and tunable crosslinking time. TA@Fe³⁺ facilitated the self‐catalysis of the polymerization reaction, and the crosslinking time could be controlled by adjusting Fe³⁺ concentration. Under NIR irradiation, the hydrogel exhibited remarkable photothermal antibacterial performance. In the full‐thickness skin defect repair experiment on mice, the prepared hydrogel dressing significantly enhanced wound healing. After 14 days, the wound healing rate (95.49%) of CPPFe@TA3 hydrogel + NIR treatment greatly exceeded that of commercial dressings. Meanwhile, the hydrogels has good electrical conductivity and thermo‐responsiveness, making them promising for skin bioelectronics in physiological signal monitoring and rehabilitation exercise management. This work therefore offers a promising strategy for developing versatile biomass‐based hydrogels, which is expected to be applicable to integrated regenerative wound healing and skin bioelectronics.
... Reproduced with permission: Copyright 2015, John Wiley and Sons. [139] epidermal growth factor (EGF). [147] According to the results of the study, networks with different fiber lengths exhibited varying drug release conditions for both TC and EGF ( Figure 11(A,B)). To be specific, the longer the fiber length was, the slower the drug released and the longer the release time was required. ...
Microfibers from natural products are endowed with remarkable biocompatibility, biodegradability, sustainable utilization as well as environmental protection characteristics etc. Benefitting from these advantages, microfibers have demonstrated their prominent values in biomedical applications. This review comprehensively summarizes the relevant research progress of sustainable microfibers from natural products and their biomedical applications. To begin, common natural elements are introduced for the microfiber fabrication. After that, the focus is on the specific fabrication technology and process. Subsequently, biomedical applications of sustainable microfibers are discussed in detail. Last but not least, the main challenges during the development process are summarized, followed by a vision for future development opportunities.
... Hydrogel consists of a network of polymers permeable to water and has been extensively investigated in interdisciplinary fields. [1] They have been widely used in applications that require close interactions with biological organisms due to their excellent biocompatibility, chemical permeability, and mechanical compliance, [2,3] such as scaffolds for tissue-engineered, [4][5][6] medical implants [7][8][9] and bioresearch. [10][11][12] However, conventional hydrogels with loose cross-links, low solid contents, and homogeneous structures are often weak and friable compared to the natural loadbearing tissues that can maintain their robustness under cyclic mechanical loading, which greatly limits their application. ...
Hydrogels are widely used in tissue engineering, soft robotics and wearable electronics. However, it is difficult to achieve both the required toughness and stiffness, which severely hampers their application as load‐bearing materials. This study presents a strategy to develop a hard and tough composite hydrogel. Herein, flexible SiO2 nanofibers (SNF) are dispersed homogeneously in a polyvinyl alcohol (PVA) matrix using the synergistic effect of freeze‐drying and annealing through the phase separation, the modulation of macromolecular chain movement and the promotion of macromolecular crystallization. When the stress is applied, the strong molecular interaction between PVA and SNF effectively disperses the load damage to the substrate. Freeze‐dried and annealed‐flexible SiO2 nanofibers/polyvinyl alcohol (FDA‐SNF/PVA) reaches a preferred balance between enhanced stiffness (13.71 ± 0.28 MPa) and toughness (9.9 ± 0.4 MJ m⁻³). Besides, FDA‐SNF/PVA hydrogel has a high tensile strength of 7.84 ± 0.10 MPa, super elasticity (no plastic deformation under 100 cycles of stretching), fast deformation recovery ability and excellent mechanical properties that are superior to the other tough PVA hydrogels, providing an effective way to optimize the mechanical properties of hydrogels for potential applications in artificial tendons and ligaments.
... Diffusion time of the encapsulated drug is a critical parameter based on which the release rate from the hydrogel can be altered for the healing of wounds with varied pharmacological specifics. The prediction of the diffusion time is of paramount importance for the clinicians in order to determine the application period of a hydrogel wound dressing [13][14][15]. The drug release experiments require a large number of study samples and are extremely time-consuming [16]. ...
... [5][6][7][8][9][10] Among them, hydrogels pose remarkable advantages over other functional dressings by providing moist environments at the wound site, and they can also realize the sustainable release of the loaded drugs. [11][12][13][14][15] Although extensive attention has been attached to them and much progress has been achieved, the drug-loading hydrogels still have some limitations. Since most of the loaded drugs are inactive substances like antibiotics and other traditional drugs, the excessive dose would cause side effects to human organs and some others. ...
Wound healing, known as a fundamental healthcare issue worldwide, has been attracting great attention from researchers. Here, novel bioactive gellan gum microfibers loaded with antibacterial peptides (ABPs) and vascular endothelial growth factor (VEGF) are proposed for wound healing by using microfluidic spinning. Benefitting from the high controllability of microfluidics, bioactive microfibers with uniform morphologies are obtained. The loaded ABPs are demonstrated to effectively act on bacteria at the wound site, reducing the risk of bacterial infection. Besides, sustained release of VEGF from microfibers helps to accelerate angiogenesis and further promote wound healing. The practical value of woven bioactive microfibers is demonstrated via animal experiments, where the wound healing process is greatly facilitated because of the excellent circulation of air and nutritious substances. Featured with the above properties, it is believed that the novel bioactive gellan gum microfibers would have a remarkable effect in the field of biomedical application, especially in promoting wound healing.
Chronic wounds constitute an increasingly prevalent global healthcare issue, characterized by recurring bacterial infections, pronounced oxidative stress, compromised functionality of immune cells, unrelenting inflammatory reactions, and deficits in angiogenesis. In response to these multifaceted challenges, the study introduced a stimulus‐responsive glycopeptide hydrogel constructed by oxidized Bletilla striata polysaccharide (OBSP), gallic acid‐grafted ε‐Polylysine (PLY‐GA), and paeoniflorin‐loaded micelles (MIC@Pae), called OBPG&MP. The hydrogel emulates the structure of glycoprotein fibers of the extracellular matrix (ECM), exhibiting exceptional injectability, self‐healing, and biocompatibility. It adapts responsively to the inflammatory microenvironment of chronic wounds, sequentially releasing therapeutic agents to eradicate bacterial infection, neutralize reactive oxygen species (ROS), modulate macrophage polarization, suppress inflammation, and encourage vascular regeneration and ECM remodeling, playing a critical role across the inflammatory, proliferative, and remodeling phases of wound healing. Both in vitro and in vivo studies confirmed the efficacy of OBPG&MP hydrogel in regulating the wound microenvironment and enhancing the regeneration and remodeling of chronic wound skin tissue. This research supports the vast potential for herb‐derived multifunctional hydrogels in tissue engineering and regenerative medicine.
There are many fields where it is of interest to measure the elastic moduli of tiny fragile fibers, such as filamentous bacteria, actin filaments, DNA, carbon nanotubes, and functional microfibers. The elastic modulus is typically deduced from a sophisticated tensile test under a microscope, but the throughput is low and limited by the time-consuming and skill-intensive sample loading/unloading. Here, we demonstrate a simple microfluidic method enabling the high-throughput measurement of the elastic moduli of microfibers by rope coiling using a localized compression, where sample loading/unloading are not needed between consecutive measurements. The rope coiling phenomenon occurs spontaneously when a microfiber flows from a small channel into a wide channel. The elastic modulus is determined by measuring either the buckling length or the coiling radius. The throughput of this method, currently 3,300 fibers per hour, is a thousand times higher than that of a tensile tester. We demonstrate the feasibility of the method by testing a nonuniform fiber with axially varying elastic modulus. We also demonstrate its capability for in situ inline measurement in a microfluidic production line. We envisage that high-throughput measurements may facilitate potential applications such as screening or sorting by mechanical properties and real-time control during production of microfibers.
Robust hydrogels offer a candidate for artificial skin of bionic robots, yet few hydrogels have a comprehensive performance comparable to real human skin. Here, we present a general method to convert traditional elastomers into tough hydrogels via a unique radiation-induced penetrating polymerization method. The hydrogel is composed of the original hydrophobic crosslinking network from elastomers and grafted hydrophilic chains, which act as elastic collagen fibers and water-rich substances. Therefore, it successfully combines the advantages of both elastomers and hydrogels and provides similar Young’s modulus and friction coefficients to human skin, as well as better compression and puncture load capacities than double network and polyampholyte hydrogels. Additionally, responsive abilities can be introduced during the preparation process, granting the hybrid hydrogels shape adaptability. With these unique properties, the hybrid hydrogel can be a candidate for artificial skin, fluid flow controller, wound dressing layer and many other bionic application scenarios.
