Abstract
The development of new, innovative, and sustainable biomaterials to be used for
wound dressing application is a current field of research gaining a lot of attention
in the biomedical (healthcare) industry. The current global market cap for topical
wound dressings as of 2020 is USD $11.4 billion dollars with an annual growth
rate of 4.4% since 2015. With the world population swelling to all-time highs year
after year, a push for natural, sustainable materials to be used in wound dressings
is necessary. Sheep’s wool is a 100% natural, biodegradable, and biocompatible
fibre composed mostly of keratin protein, the same physical structure as collagen
(protein) and largely forms the outer layer of human skin. Currently in New
Zealand, coarse wool fibre produced from sheep is largely considered for carpet
and fabrics. Some coarse wool is difficult to process into textiles as its fibre
diameter is too large and fibre length is too short for the use in carpet or textile
(garment) production and so is considered a waste product. These detrimental
issues create an opportunity for this study to be conducted. Fundamentally, this
study outlines a novel method to improve hydrophilic properties of
hydroentangled wool fibre fabrics. This was achieved by combining chemical
exposure and microwave (MW) irradiation techniques to produce a super
hydrophilic biomaterial for the intended end-use as the middle absorbent layer of
a composite wound dressing. A process of elimination was used to determine the
most effective chemical solution concentration for best results. Wool fabric
specimens were treated with a range of different concentrations of potassium
hydroxide (KOH) only and potassium hydroxide/hydrogen peroxide (KOH/H202)
treatments for different time periods. Characterisation of these specimens
showed 2% KOH/2% H202 treatments were best. Further optimisation was
conducted by adjusting irradiation settings of MW to find the optimum
treatment. Optimised wool fabric characterisation testing protocols included
Fourier-transform infrared spectroscopy (FTIR), water droplet contact angle,
dye droplet surface area absorption test, a visual examination of wool fibre
surface via scanning electron microscopy (SEM), water absorption capacity, and
keratinocyte cell biocompatibility tests (viability and proliferation). The
characterisation tests of all 2% KOH/2% H2O2 + MW irradiation treatments were
promising and can be considered successful to some degree. However, 2%
KOH/2% H2O2 + MW irradiation for 2 minutes at 40oC was considered the most
effective treatment for producing a super hydrophilic hydroentangled wool
material.