Scientists have successfully restored erectile function in pigs with damaged penises using artificial tissue.
“We were surprised by the results of animal studies that the penis quickly regained normal erection,” said Xuetao Shi, a tissue engineer at China Southern University of Technology.
About half of people with a penis have some form of erectile dysfunction between the ages of 40 and 70. Some people have Peyronie’s disease, where scar tissue from past injuries causes pain and disability.
Treatment usually involves transplanting tissue from another part of the body into the penis to replace the damaged area. However, our immune system is good at rejecting the insertion of biological material, and even successful grafts can cause problems such as shortening of the penis due to differences in tissue types.
So Muyuan Chai, a tissue engineer at South China University of Technology, and his colleagues turned to synthetic tissue as a potential alternative.
Mammalian spongy erectile tissue is composed of parallel, wavy fibers of collagen (with a small amount of elastin) stacked together called tunica albuginea (TA). As the spongy tissue swells with blood, the fibers take up space while simultaneously straightening and supporting everything.
In addition, when the AT fibers are fully stretched, they create stiffness, control and limit shape change, and function as a hydrostatic framework that resists external deformation.
Researchers made synthetic fibers that mimic these fibers by testing different compositions in a balloon model. When isotropic polyvinyl alcohol gel is stretched and cross-linked to arrange the fibers in parallel, it expands and contracts in the same direction as TA, and the entire erectile tissue changes from soft to hard.
Chai et al. named this bionic creation “artificial media” (ATA). It can withstand fatigue, maintain toughness, and withstand needle sticks during suturing while repeating relaxation and stretching.
The synthetic fibers were then tested in pigs with AT lesions.
“One month after the intervention, the ATA group had good but not perfect repair,” says Shi.
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