Treatment of Coral Wounds by Combining an Antiseptic Bilayer Film and an Injectable Antioxidant Biopolymer

Abstract

coral reefs are vital for the marine ecosystem and their potential disappearance can have unequivocal consequences on our environment. Aside from pollution-related threats (changes in water temperature, plastics, and acidity), corals can be injured by diseases, predators, humans and other invasive species. Diseases play an important role in this decline, but so far very few mitigation strategies have been proposed and developed to control this threat. in this work, we demonstrate that recently developed bi-layer human skin wound treatment patches containing antiseptics and natural antioxidants with controlled-release capacity can be adapted to treat scleractinian coral wounds effectively. A hydrophilic bilayer film based on polyvinylpyrrolidone (PVP) and hyaluronic acid was used to cover the open wounds while delivering the antiseptics for rapid action. Afterwards, the hydrophilic bi-layer covered wound was sealed with an antioxidant and hydrophobic ε-caprolactone-p-coumaric acid copolymer by melt injection at low temperatures. treated coral injuries were monitored both in aquaria system and in natural environment in Maldives for over 4 months to reduce the number of entry points for organisms that could lead to diseases. the corals well-tolerated both biomaterials as well as the antiseptics incorporated in these materials. the treatments displayed self-adhering properties, tuneable dissolution time, and biocompatibility and stimulated regeneration properties within the coral wound. As such, this work demonstrates that certain human skin wound treatment materials can be successfully adapted to the curing of coral wounds and delivery of specific drugs to slow down, reduce or even stop the spread of diseases in scleractinian corals as well as in all other benthic organisms affected by uncontrolled pathologies.

Effectiveness of topical antibiotics in treating corals affected by Stony Coral Tissue Loss Disease

“…Past uses of antibiotics on diseased corals have included utilization as a diagnostic tool to help identify bacteria as a presumptive pathogen in white band disease (Kline & Vollmer, 2011;Sweet, Croquer & Bythell, 2014) as well as water dosing to halt SCTLD lesion 2018-2020, personal communication). The use of skin wound treatment patches containing antiseptics, antioxidants and/or antibiotics have also shown promise in helping mechanically damaged corals to heal (Contardi et al, 2020). However, the results presented here represent the first known use of topical antibiotics as a disease treatment tool to preserve wild populations.…”

Does Predation Exacerbate the Risk of Endosymbiont Loss in Heat Stressed Hermatypic Corals? Molecular Cues Provide Insights Into Species-Specific Health Outcomes in a Multi-Stressor Ocean

“…If we transpose these results into a real-word, multi-stressor scenario, in which there are repeated events of thermal stress as well as corallivory, recurrent bleaching, variable wound sizes (in-depth, perimeter, and location), and multiple wounds occurring simultaneously which need longer healing times ( Cróquer et al, 2002 ); then, coral condition and organism ability to respond to multiple interacting stressors may be significantly affected, to the point of becoming compromised ( Henry and Hart, 2005 ). Moreover, coral wounds can be the starting point for disease, especially in thermally stressful environments, during which disease outbreaks increase ( Tracy et al, 2019 ), such as black-band disease or white-band disease ( Mayer and Donnelly, 2013 ; Contardi et al, 2020 ). Therefore, the combination of these stressors could facilitate the spread of disease vectors ( Porter and Tougas, 2001 ).…”

Exploring the performance of mid‐water lagoon nurseries for coral restoration in the Maldives

“…On Athuruga, the disease spread despite the timely removal of diseased tissue, which has also been observed in other studies (Miller et al 2014). Since diseases emerge as an increasing threat to coral restoration, a monitoring framework has lately been suggested and a new tool for treating coral injuries from fragmentation has been tested in the Maldives (Contardi et al 2020; Moriarty et al 2020).…”