Copyright © 2022 Foshan MBRT Nanofiberlabs Technology Co., Ltd All rights reserved.Site Map
In the past, people used traditional dressings to treat wounds; their purpose was to keep the wound dry and prevent the entry of harmful bacteria. Today, we know that a moist and warm environment around the wound allows for faster healing, as it favors the regeneration of cells and tissues. Dressings can be differentiated based on their function (antimicrobial, occlusive, debridement, absorption), the materials used, or the physical form in which they occur (ointment, film, foam, gel). Further classification can be divided into traditional, modern, and advanced dressings.
Traditional dressings need to be changed frequently to avoid maceration of healthy tissue; in addition, they may have other disadvantages, such as adhesion due to excessive drainage. Modern dressings are manufactured to enhance the healing function of the wound, rather than simply covering it and isolating it from the external environment. Advanced dressings refer to skin replacement through tissue engineering. In fact, neither traditional nor modern dressings can replace lost tissue and promote wound healing. From this point of view, it is important to choose the right dressing; this depends on the purpose of the dressing, the wound condition, the activity level, and the needs of the patient/individual. Therefore, the dressing should protect the wound from additional trauma, ensure environmental humidity, absorb or remove excess exudate, prevent contamination, and provide an environment that is conducive to the body's natural defense mechanisms.
The main point of this paper
Challenges in wound care:
Traditional treatments are inadequate or ineffective, and new pharmacological approaches are needed.
Application of transdermal patches:
As one of the local drug delivery methods, it is used to locally provide a predefined dose of active ingredients with a controlled release rate.
Advantages of electrospun fiber systems:
Systems based on electrospun fibers have attracted scientific interest in multiple fields due to their unique properties, including wound dressings and drug delivery.
Application of nanofiber membranes in wound healing:
Electrospun fibers are conducive to liquid evaporation and prevent bacterial contamination due to their pore structure and oxygen permeability, and drugs and other healing promoters can be added.
Supercritical impregnation process:
It is used to impregnate drugs into nanofibers to achieve sustained release of drugs and promote wound healing.
Combination of active compounds:
Mesopolysaccharide (MSG) and lactoferrin (LF) are used as synergistic compounds to improve wound healing.
Properties of polyurethane (PU):
As a good polymer candidate, it has good mechanical flexibility, biodegradability and diverse physicochemical properties.
Design of double-layer transdermal patch:
Combining electrospinning and supercritical impregnation technology, a new double-layer transdermal patch is designed to load MSG and LF into PU fibers
Bilayer system design:
Three different bilayer systems for skin wound healing were designed, each with a different drug loading method.
Morphology and distribution:
SEM analysis showed uniform drug distribution on the microfibers.
Drug loading:
The highest loading of mesoglossic acid and lactoferrin was 0.062 g/g and 0.013 g/g, respectively.
Hydrophilicity and fluid retention:
Hydrophilicity and fluid retention analysis were performed to evaluate the potential as an active patch.
In vitro release kinetics:
In vitro assays performed by Franz diffusion cells showed that drug release followed a two-step release mechanism and reached equilibrium after about 30 hours.
Cytotoxicity evaluation:
No cytotoxic events were observed when the electrospun membranes were in contact with HUVEC, HaCaT, and BJ cell lines.
Healing promoting ability:
The most promising systems were evaluated for their ability to promote the healing process by HaCaT cell scratch test.
Single and double-layer PU films charged with MSG and LF were prepared for wound dressings by electrospinning and supercritical CO2-assisted impregnation. The three devices combined the two technologies in different ways. Supercritical impregnation tests were carried out at P = 200 bar, T = 40 °C. SEM analysis of the samples showed that the chosen process conditions had no effect on the fibers. In fact, they maintained their initial size and orientation. The results report the loading of the two active ingredients after 24 h of treatment: in the case of electrospun MSG, the loading of MSG was 6.2%.
Lactoferrin was the most promising sample to achieve the loading rate, as it could reach around 1.3% compared to the MSG electrospun samples. Release tests demonstrated the benefits of fiber impregnation; in fact, the comparison of the three samples showed that the sample with electrospun MSG, unlike the other two, released more slowly and more uniformly.
