A new bioadhesive patch joined tissues inside the body
Korean researchers have developed bioadhesive patches based on mussel proteins that can adhere to wet surfaces. Tests have shown the development's biocompatibility and lack of cytotoxicity. In addition, for a stronger connection of different organs and tissues medics can change the composition of the substance.
The effect of adhesion - when molecules of dissimilar materials stick to each other - is used in medicine to heal wounds. But often adhesive patches heal external surfaces. Difficulties arise when it is necessary to bind internal organs, because water molecules interfere with the strong connection of surfaces. And because of the different mobility of the organs, different bonding forces are needed. In addition, such patches must be biocompatible and decompose without toxic emissions.
Korean medical researchers have developed a customizable bioadhesive wet patch (CUBAP) based on mussel proteins that can bond to wet surfaces. The article about it was published in the journal Advanced Materials. According to experts, the development has controlled biodegradability and stretchability.
The new patch was created from a mixture of acrylic, polyacrylic, polymethacrylic acids and mussel adhesive proteins, which bond well with surfaces even in water conditions. In the dry state, CUBAP had no adhesive properties, but when the researchers added water to the samples, the surface energy of the substance increased.
Changing the proportion of methacrylic acid in CUBAP affected its hydrophobicity - this, as the authors of the paper noted, can increase the duration of patch degradation in a wet environment. Also, different ratios of acids in the substance affected its extensibility and maximum tensile stress - adhesive strength increased with increasing acrylic acid content. As water was added to the CUBAP samples, their flexibility and shear stiffness changed. The researchers said adjusting the composition in the substance could allow the stretchability and other properties of the patch to be varied for different tissues and organs.
The medics tested CUBAP on skin, muscle, heart, liver and other organs: they found that the highest adhesion strength was on skin and slightly less on muscle. On the pig's wet organs - heart, lungs and liver - the substance held for three days. In addition, CUBAP has bilateral adhesion and can be attached to various sensors and implants.
In addition, the different composition of CUBAP also influenced its biodegradability. Tests showed that a high proportion of methacrylic acid slowed down the degradation of the substance in vivo. Other assays showed no cytotoxicity of CUBAP, and biocompatibility tests on mice showed no inflammation. The patch, the researchers say, could be used, for example, to treat bladder perforations or atrial septal defects.
"This study paves the way for personalized medical applications. We plan to improve and refine this process during follow-up studies for effective applications in various biomedical fields," said co-author Hyung Joon Cha, who co-authored the paper.