Electrospining Machine: Multifunctional Janus Nanofiber Membrane with unidirectional water transport and pH-responsive color-changing for wound dressing

Recently, Professor Xin Binjie and Associate Professor Ou Kangkang from Shanghai University of Engineering and Technology, together with Dr. Huang Yinjun from the First People's Hospital of Shanghai, published the latest research results in the journal "Journal of Colloid and Interface Science" titled "Multifunctional Janus nanofiber membrane with unidirectional water transport and pH responsive color changing for women dressing".

Method

Researchers have designed and prepared Janus structured nanofiber membrane wound dressings with unidirectional moisture conductivity, pH responsive color change, and wound healing promotion through layer by layer electrospinning technology. This dressing consists of a hydrophilic layer of polyacrylonitrile/sodium polyacrylate/anthocyanin (PAN/SPA/An) with antioxidant and pH responsive functions, as well as a hydrophobic layer of poly (3-hydroxybutyryl-co-3-hydroxyvalerate) (PHBV), which can achieve unidirectional drainage of wound exudate without reverse osmosis. The presence of anthocyanins in the dressing endows it with good pH responsive color change, antioxidant capacity, and cell compatibility, with a DPPH free radical scavenging rate of 98.5%. This dressing has excellent exudate management and biocompatibility effects. It was used in a full-thickness mouse skin defect model experiment and found that the Janus structure dressing can accelerate wound healing. This study provides new insights into the design and manufacture of multifunctional wound dressings, which have great potential in accelerating wound healing.

Research highlights

Janus structured dressings achieve unidirectional export of wound exudate: 

the thickness of the hydrophobic layer directly affects the unidirectional water transport properties of Janus nanofiber membranes, and the membrane thickness can be adjusted by changing the spinning time. The contact angle of the individual PHBV nanofiber membrane decreased from 116.27 ° to 111.96 ° within 300 seconds. In contrast, the contact angle of the outer layer of PAN/SPA alone decreased to 0 ° within 0.5 s, indicating that both layers exhibited good hydrophilicity and hydrophobicity, respectively. However, when the two layers are combined, it is known that as the PHBV spinning time increases, the initial contact angle on the hydrophobic side of the bilayer membrane gradually increases, and the time required to reduce it to 0° also increases. It indicates that when the thickness of the hydrophobic layer is appropriate, Janus membranes with a double-layer hydrophobic hydrophilic structure can exhibit unidirectional flow characteristics.

Real time monitoring of wound microenvironment using pH color changing dyes: 

The pH value of the wound is an important parameter for wound infection. When the wound is within the normal pH range, it helps promote angiogenesis and epithelialization while maintaining the presence of symbiotic bacteria. Affected by the metabolites produced by the increase in bacterial flora, the infected wound tends to be alkaline. Therefore, constructing pH responsive color changing dressings is an effective way to early identify potential wound deterioration and monitor the wound healing process without removing the dressing or interfering with the wound microenvironment. The synergy of unidirectional moisture wicking and color changing dyes can prevent dyes from escaping to the wound site, achieving real-time monitoring of the wound microenvironment while unidirectional moisture wicking. This article also provides a detailed analysis and explanation of the discoloration mechanism of anthocyanins; Explored the excellent color changing effect, sustained release effect, and outstanding stability of nanofiber membranes under different pH conditions. The application of this dressing in a mouse model of full-thickness skin defect wound healing revealed that its excellent unidirectional liquid transport properties and antioxidant capacity can promote wound healing.

Janus structured nanofiber dressings exhibit excellent breathability, moisture permeability, mechanical properties, cell compatibility, and antioxidant properties, while quickly responding to color changes in environments with different pH values. The mouse model of full-thickness skin defect healing shows that the dressing has excellent wound healing ability, providing certain technical guidance for the treatment of chronic wounds in clinical practice. In the future, this dressing is expected to be widely used in clinical practice, making important contributions to improving patients' quality of life and promoting wound healing.

Paper link:

https://doi.org/10.1016/j.jcis.2024.10.137