Surgical site infection is one of the most common infections affecting nearly 300,000 patients in the U.S. within 30 days of their operation each year. It is estimated that about $10 billion is spent on added healthcare costs and more than 13,000 of those infected patients die. Postsurgical infections may increase the length of postoperative hospital stays by at least seven to ten days, and rates of readmission to the hospital, cost, and rates of death. Thus, SSIs result in widespread suffering of patients and economic loss.
Researchers used electrospinning to prepare dressings as it is a versatile, simple, cost-effective, and reproducible technique with the bioactive form of vitamin D: 1,25-dihydroxyvitamin D3. Electrospun nanofiber wound dressing can be used over hydrogels or sponges for local drug delivery; they also provide scar-free healing property.
To kill the microbes, the researchers created the dressing capable of delivering vitamin D on a sustained basis over four weeks. This significantly produced a peptide, hCAP18/LL37, that kills microbes by disrupting their membranes.
According to Jingwei Xie, assistant professor at the University of Nebraska Medical Center, the nanofiber-based structures contain the inactive form of vitamin D which is 25-hydroxyvitamin D3- and a toll-like receptor ligand that was to activate cells converting 25D3 to the bioactive form, 1,25D3. The dressing released it and converted in vitamin D target genes, which produces LL37 peptide.
As the dressings work by enhancing innate immune responses, the single-target antimicrobial compounds are less likely to give to drug resistance. The dressings were examined on human skin which was collected from plastic surgery patients, were kept in a culture dish, in-vitro with keratinocyte and monocyte cell lines, and in vivo in a model of mouse. There was a hope of inducing the genes in a model system, and now, it may be possible to heal the infections. 1,25D3-induced expression of hCAP18 by these nanofiber dressings is indeed a step toward better wound healing.