Electrospinner: Strong ultra-fine hydrogel fibers: Water vortex stretching method, fiber-coated drug delivery is more amazing!

Background

Hydrogel fibers have the performance characteristics of hydrogels and the structural advantages of fibers. They have attracted extensive attention from researchers due to their unique biological/engineering manufacturing advantages. Hydrogel fibers that are compatible with traditional weaving, spinning, stacking and other processing strategies can effectively construct one-dimensional, two-dimensional and three-dimensional products, and have great application prospects in the biomedical field. At present, the preparation methods of hydrogel fibers mainly include template method, pregel drawing method, electrospinning/solution jet spinning, microfluidic spinning method and wet spinning method. However, due to the three-dimensional network structure characteristics and weak mechanical properties of hydrogels, it is impossible to prepare small-diameter hydrogel fibers by mechanical drawing, which greatly limits the application research of hydrogel fibers. Therefore, it is urgent to develop an efficient and widely adaptable method for the large-scale preparation of hydrogel fibers with controllable diameter and excellent mechanical properties.

Recently, Associate Researcher Li Dawei of Jiangnan University and Professor Chen Chang and Dr. Sun Weiyan of Shanghai Pulmonary Hospital published a research result entitled "Vortex-inspired Hydrodynamic Drafting Spinning Platform for Large-scale Preparation of Hydrogel Fibers" in Advanced Fiber Materials. In this work, a hydrodynamic stretch spinning platform (HDSP) was designed for the large-scale preparation of hydrogel fibers with controllable diameters. By adjusting the speed difference between the fiber and the fluid vortex, HDSP can process different hydrogel systems into hydrogel fibers with controllable diameters, and the fineness can be flexibly adjusted between 15 and 500 μm. The experimental results show that the spinning platform has industrial production potential, efficient stretching capacity, significant drug loading activity, and good compatibility with subsequent product processing.

The main point of this paper

In nature, water vortices can cause objects to rotate in a specific direction, which is related to the drag between the object and the water flow. Therefore, by adjusting the speed difference between the fluid vortex and the fiber, the drag between the two is changed, thereby effectively regulating the diameter of the hydrogel fiber (Figure 1a-e). HDSP can continuously prepare hydrogels with uniform diameters. HDSP equipped with a multi-channel spinning device provides a feasible solution for the industrial production of hydrogel fibers (Figure 1f). Based on the molding mechanism and microstructure of hydrogel fibers, hydrophobic and hydrophilic drugs can be effectively loaded (Figure 1g-i).

In order to verify the wide adaptability of HDSP, fibers of three systems of calcium alginate, chitosan and polyacrylonitrile were prepared respectively. The results show that the soft and efficient drawing force of HDSP can significantly reduce the fiber diameter (Figure 2a-b); in addition, hydrogel yarns, fiber bundles, nonwoven fabrics, woven fabrics and fiber scaffolds can also be constructed (Figure 2c-d). The diameter of the hydrogel fiber determines the microstructure of the subsequent product. As the fiber diameter increases, the pore size of the hydrogel nonwoven fabric increases, and the fibers become loosely bonded (Figure 2e)

Next, the hydrogel-based nonwoven material (HNs) wound dressing was constructed by combining the efficient and simple HDSP and wet-laid web forming technology (Figure 3a-c). The mechanical properties of HNs were enhanced by the silk protein network welding mechanism (Figure 3d-e). In addition, HNs exhibited excellent moisture management and bacterial barrier properties (Figure 3f-l)

The excellent hydrophilicity and rich calcium ions of HNs give them excellent hemostatic ability (Figure 4), which is due to the hydrophilicity that can quickly adsorb and aggregate blood cells, activate platelets, and promote the activation of coagulation factors; calcium ions participate in both intrinsic and exogenous coagulation pathways to achieve rapid hemostasis.

The antioxidant activity of HNs was further evaluated by stimulating cells to produce oxidative stress through H2O2. The experimental results showed that HNs can effectively regulate wound oxidative stress by removing reactive oxygen species (Figure 5a-h); in addition, HNs can regulate macrophage phenotype to improve wound microenvironment and promote wound healing (Figure 5i-k)

The mouse full-thickness skin defect model verified the significant effect of HNs as wound dressings in regulating oxidative stress, preventing wound inflammation and promoting wound healing (Figure 6). The experimental results showed that the regeneration rate of skin tissue in the HNs treatment group with both quercetin and silk fibroin was significantly faster than that in other treatment groups

Electrospinning Nanofibers Article Source:

https://link.springer.com/article/10.1007/s42765-024-00466-w