Accidents and major injuries cost a lot of expenses medically and induce post-op healing primarily through administration of wound treatment. Researches have been trying to produce alternative and cost free methods to accelerate wound healing without the expense of acquiring contamination from infections outside a sterile environment.
Findings from the Oregon State University researchers and collaborators, as published in Nanomedicine, has confirmed the production of an antimicrobial substance through wound dressings made from nanofibers.
Surgical site injuries are some of the most common healthcare-associated infection and even produced results causing widespread human suffering including economic loss, according to a research obtained from Sciencedaily.
Researchers used electrospinning to prepare dressings made from bioactive vitamin D: 1,25-dihydroxyvitamin D3, or 1,25(OH)2D3.
"Electrospinning is a versatile, simple, cost-effective and reproducible technique for generating long fibers made with nanoscale diameters," said Adrian Gombart, co-author and professor of biochemistry and biophysics in OSU's College of Science.
These nanofibers provide advantageous functionality through scar free healing and are much more preferred than hydrogels or sponges.
The dressings the researchers created have proven capable of delivering vitamin D for over four weeks, and significantly induced the production of a peptide which kills microbes by disrupting their structural membranes. These dressings work by enhancing innate immune responses rather than by containing conventional, single-target antimicrobial compounds, which are less likely to contribute to drug resistance. The dressings were tested on human skin where they had collected from plastic surgery patients placed in a petri culture dish, as well as in vitro with keratinocyte and monocyte cell lines, and in vivo in a mouse model.
"This study was proof of principle," said by another co-author Arup Indra, and an associate professor of pharmacy at OSU. "It looks like we can induce these various genes in a model system and now we can start looking at healing and preventing infection."
Wound healing in burns and foot ulcers
As stated from the Hindu.com, scientific researchers from the Indian Institute of Technology (IIT) Guwahati have developed bioactive wound dressings and bio-artificial skin by using silkworm silk fibroin as matrix and a coating of substances made with recombinant spider silk proteins. If animal trials are also successful, then these wound dressings might help in treating chronic and severe wounds such as diabetic foot ulcers, while also including skin graft which might come handy for burn patients.
These wound dressings reduce bacterial population by nearly fourfold and showed good anti-biofilm properties, more so, the silk scaffolds seeded with human dermal and epidermal cells led to the development of bio-artificial skin.
The team which was led by Prof. Biman Mandal from the Department of Biosciences and Bioengineering also integrated functioning blood vessels into the bio-artificial skin by using human dermal microvascular endothelial cells.
Nanofibrous silk mat for wound dressing was prepared using silkworm fibroins as the matrix and was coated with 0.1 mg/ml of recombinant spider silk proteins containing antimicrobial peptides, and other cell binding proteins and growth factor peptide. Whereas the growth factor stimulates cell proliferation and recruits cells to the wound, joining together with the healing process is the cell binding protein which provides cell recruitment to the wound site and also in the cell migration process.
“The spider silk has high affinity towards silkworm silk and self-assembles as a thin coating on top of the matrix without the use of any chemicals. Since the interaction between spider and silkworm silk is strong, the coating remains stable,” says Dimple Chouhan from IIT Guwahati. Both mulberry and non-mulberry silk varieties were said to have been also suitable for producing the matrix, given that with the non-mulberry silk showing quicker and stronger self-assembly when added with spider silk.
The two cationic peptides — Magainin I and Lactoferricin — contained in the spider silk-coated silk mats showed good antibacterial activity against two common bacteria found in wounds — Pseudomonas aeruginosa and Staphylococcus epidermidis.
“The cationic peptides are non-specific which means any bacteria could be targeted. We tested these peptides against both Gram-positive and Gram-negative bacteria and the peptides reduced both populations and even stopped their growth,” says Prof. Mandal.
Since chronic wounds lack cell binding proteins and growth factor to recruit skin cells to the site, the healing gets delayed or obstructed. But the proteins and antimicrobials in the coated silk mat helped the team achieve “functionally active mats” for wound dressing.
In order to develop bio-artificial skin grafts, a scaffold made from silkworm silk protein was coated with recombinant spider silk protein containing RGD proteins that promote cell binding and proliferation. Under in vitro conditions, the scaffold was cultured with human dermal (fibroblasts) and epidermal (keratinocytes) skin cells. While the dermal and epidermal skin cells led to the creation of a bilayer skin graft, blood vessels were then developed in the skin graft by culturing the scaffold with human dermal microvascular endothelial cells.
“We could mimic both the epidermal and dermal layer of the skin and thus come up with an efficient and affordable way to form functionalized constructs for tissue engineering and drug screening applications”, says Chouhan.
“We are currently performing follow up studies using various animal models to examine the efficacy of bioactive constructs, to understand the healing properties, and study everyday cell-material interactions,” Prof. Mandal says.
Wound healing in diabetic foot
Most people with diabetes will have at least one foot ulcer at some point in their life. These could even lead to severe wound infections and other disease complications. If left untreated, it can result to amputation.
In an article written by British Jack Woodfield from Diabetes.co, a bandage that could speed up the healing process of diabetic foot sores has been developed. This bandage device, invented by researchers at Northwestern University in Illinois, uses the body's own healing ability without taking drugs or other pharmaceutical products. After being tested, it was found to heal diabetic wounds 33% faster as compared to regular bandages.
Study author Professor Guillermo Ameer said: "We identified a segment of a protein found in the skin that is important to wound healing, incorporated it, and made it into an antioxidant molecule that self-aggregates at body temperature to create a scaffold that facilitates the body's ability to regenerate tissue at the wound site.
A liquid form is applied like a bandage which then solidifies into a gel. As it develops through the wound, it closes and heals the injury site. Saline is required to remove the bandage without pulling the skin.
"Wounds often have irregular shapes and depths. Our liquid can fill any shape and then stay in place. Other bandages are mostly based on collagen films or sponges that can move around freely unintentionally and shift away from the wound site," added Prof Ameer.
Although this pioneering technology can be used for any wound, the research team focused their efforts on helping those diabetic patients who are at higher risk of obtaining foot wounds which can be difficult to treat. In addition, chronic wounds might also benefit from this bandage to provide advanced healing.
More research is set to be carried out for the bandages to gain official approval from the US Food and Drug Administration (FDA).