Fabrication and characterization of hydrogel scaffold for epidermal skin layer

Abstract

An estimated 265,000 people die from burns annually. The large majorities are from low- and middle-income countries and approximately half are from the South-East Asia region. The survival of extensive burns incidents depends on immediate treatment of burn wounds followed by proper wound coverage to eliminate risk of infection. Traditional split-thickness autologous skin grafts are considered the gold standard for permanent wound treatment. However, there is limited availability of donor sites in the events of major burns. Fortunately, it is possible to harvest large amounts of cultured epithelium using cultured epithelial autograft (CEA) technique. Although confluent sheets of CEA have been widely used over the last two decades for treatment of third degree burn wounds, CEA has its limitations. A major disadvantage is the long cultivation period of 3 to 4 weeks to form fully stratified, functional cell sheets, which delays the treatment. Furthermore, CEA sheets are extremely fragile as each sheet is 2 to 8 cell layers thick or 40 to 160 µm in thickness. In addition, they do not give satisfactory healing outcomes and are highly susceptible to infection. Nevertheless, there are other techniques where cells are seeded on a scaffold with sufficient mechanical support to form a monolayer scaffold. However, epidermis is a multi-layered structure consisting of keratinocytes -with varying degrees of differentiation. To mimic the natural micro-environment of skin tissue, bioprinting would be a promising approach to fabricate intricate hydrogel scaffolds for cell seeding. Hence, there is a need to find a gel formulation to create a printable hydrogel scaffold. In this report, progressive series of experiments will be conducted to formulate a printable bio-ink followed by characterization and demonstration of the gel printability for building a multi-layered construct.