A low-cost, antimicrobial aloe-alginate hydrogel film containing Australian First Nations remedy ‘lemon myrtle oil’ (Backhousia citriodora) – Potential for incorporation into wound dressings
Dinuki M. Seneviratne,
Brooke Raphael,
Eliza J. Whiteside,
Louisa C.E. Windus,
Kate Kauter,
John D.W. Dearnaley,
Pratheep K. Annamalai,
Raelene Ward,
Pingan Song,
Paulomi (Polly) Burey
Affiliations
Dinuki M. Seneviratne
School of Health and Medical Sciences, University of Southern Queensland, Toowoomba, Queensland, Australia; Centre for Health Research, University of Southern Queensland, Toowoomba, Queensland, Australia; Centre for Future Materials, University of Southern Queensland, Toowoomba, Queensland, Australia; Corresponding author. UniSQ Toowoomba, 487-535 West Street, Darling Heights, QLD, 4350, Australia.
Brooke Raphael
School of Agriculture and Environmental Science, University of Southern Queensland, Toowoomba, Queensland, Australia
Eliza J. Whiteside
School of Health and Medical Sciences, University of Southern Queensland, Toowoomba, Queensland, Australia; Centre for Health Research, University of Southern Queensland, Toowoomba, Queensland, Australia; Centre for Future Materials, University of Southern Queensland, Toowoomba, Queensland, Australia; Institute for Resilient Regions, University of Southern Queensland, Toowoomba, Australia
Louisa C.E. Windus
School of Health and Medical Sciences, University of Southern Queensland, Toowoomba, Queensland, Australia; Centre for Future Materials, University of Southern Queensland, Toowoomba, Queensland, Australia
Kate Kauter
School of Health and Medical Sciences, University of Southern Queensland, Toowoomba, Queensland, Australia
John D.W. Dearnaley
School of Agriculture and Environmental Science, University of Southern Queensland, Toowoomba, Queensland, Australia
Pratheep K. Annamalai
Centre for Future Materials, University of Southern Queensland, Toowoomba, Queensland, Australia; School of Agriculture and Food Sustainability, The University of Queensland, Brisbane, Queensland, Australia
Raelene Ward
Centre for Health Research, University of Southern Queensland, Toowoomba, Queensland, Australia; Institute for Resilient Regions, University of Southern Queensland, Toowoomba, Australia; Kunja Traditional Owner, Cunnamulla, Queensland, Australia
Pingan Song
Centre for Future Materials, University of Southern Queensland, Toowoomba, Queensland, Australia; School of Agriculture and Environmental Science, University of Southern Queensland, Toowoomba, Queensland, Australia
Paulomi (Polly) Burey
Centre for Future Materials, University of Southern Queensland, Toowoomba, Queensland, Australia; School of Agriculture and Environmental Science, University of Southern Queensland, Toowoomba, Queensland, Australia
Chronic wounds pose a global public health challenge, particularly in remote settings where access to specialised wound care and dressings can be limited and cost-prohibitive. First Nations communities in Australia are at a significantly higher risk for developing chronic wounds and this risk further increases for people living in remote regions. There is an urgent need to develop inexpensive but effective wound dressings to improve wound outcomes. Over the past decade, sodium alginate (SA)-based hydrogel polymers have emerged as a cost-effective and biocompatible component in wound dressings, and many have been successfully commercialised. In this study, we have developed and evaluated various prototypes of SA-based hydrogels with the addition of another low-cost component, aloe vera (AV) to further tailor the physicochemical properties of the hydrogel. Since the presence of microbes is a major contributor to the pathophysiology of chronic wounds, we also evaluated the antimicrobial activity of lemon myrtle oil (LMO) (Backhousia citriodora) incorporated into the hydrogel, a remedy used traditionally by First Nations Australians. Novel formulations of AV-SA-LMO hydrogel prototypes in the absence and presence of lemon myrtle oil (at a concentration of 5 μg/mL) were assessed for their physicochemical and antimicrobial properties and compared to a commercially available hydrogel-based dressing. The addition of lemon myrtle oil imparted viscoelastic behaviour for improved processability of AV-SA-LMO hydrogel prototypes, while increasing protein adhesion, enhancing physical properties, and demonstrating antimicrobial activity against the common wound-infecting microbes Staphylococcus epidermidis and Candida albicans. Fourier transmission infrared (FTIR) spectra confirmed the molecular structures of the hydrogel prototypes as predicted. The prototypes also demonstrated biocompatibility with the HaCaT human keratinocyte cell line. This study has provided preliminary evidence that a 25:75 aloe vera:sodium alginate hydrogel with 5 μg/mL lemon myrtle oil has comparable physicochemical characteristics to a commercial hydrogel-based wound dressing and antimicrobial properties against S. epidermidis and C. albicans.
