Multifunctional Gelatin/Chitosan Electrospun Wound Dressing Dopped with Undaria pinnatifida Phlorotannin-Enriched Extract for Skin Regeneration

The similarities of electrospun fibers with the skin extracellular matrix (ECM) make them promising structures for advanced wound dressings. Moreover, infection and resistance in wounds are a major health concern that may be reduced with antibacterial wound dressings. In this work, a multifunctional wound dressing was developed based on gelatin/chitosan hybrid fibers dopped with phlorotannin-enrich extract from the seaweed Undaria pinnatifida. The intrinsic electrospun structure properties combined with the antimicrobial and anti-inflammatory properties of phlorotannin-enrich extract will enhance the wound healing process. Electrospun meshes were produced by incorporating 1 or 2 wt% of extract, and the structure without extract was used as a control. Physico-chemical, mechanical, and biological properties were evaluated for all conditions. Results demonstrated that all developed samples presented a homogenous fiber deposition with the average diameters closer to the native ECM fibrils, and high porosities (~90%) that will be crucial to control the wound moist environment. According to the tensile test assays, the incorporation of phlorotannin-enriched extract enhances the elastic performance of the samples. Additionally, the extract incorporation made the structure stable over time since its in vitro degradation rates decreased under enzymatic medium. Extract release profile demonstrated a longstanding delivery (up to 160 days), reaching a maximum value of ~98% over time. Moreover, the preliminary antimicrobial results confirm the mesh’s antimicrobial activity against Pseudomonas aeruginosa and Staphylococcus aureus. In terms of biological characterization, no condition presented cytotoxicity effects on hDNF cells, allowing their adhesion and proliferation over 14 days, except the condition of 2 wt% after 7 days. Overall, the electrospun structure comprising phlorotannins-enriched extract is a promising bioactive structure with potential to be used as a drug delivery system for skin regeneration by reducing the bacterial infection in the wound bed.

Sulfated Polysaccharide From Undaria Pinnatifida Induces Apoptosis and Inhibits Proliferation, Migration, and Invasion in Ovarian Cancer via Suppressing the Hedgehog Signaling Pathway

Objective: To investigate the effects of sulfured polysaccharide from Undaria pinnatifida (SPUP) on the biological behaviors of ovarian cancer (OC) cells and its potential mechanism.Methods: Sulfated polysaccharide from Undaria pinnatifida (SPUP) was extracted and characterized through a combination of chemical analysis, IR spectra, UV-Vis, gas chromatography, and high-performance gel permeation chromatography. OC and human ovarian surface epithelial cells were used as working model in vitro for evaluation of SPUP’s therapeutic effects. A combination of CCK-8, Transwell, and flow cytometry assay was used to measure the proliferation, migration, invasion, and apoptosis of OC cells, respectively. In addition, the protein expression levels of cells were also measured by Western blot.Results: SPUP suppressed OC development from three different perspectives: 1) SPUP treatment significantly inhibited the proliferation of OC in a dosage-dependent manner (p < 0.05); 2) SPUP inhibited the migration and invasion of OC cells confirmed by scratch and Transwell experiments (p < 0.05); 3) SPUP induced apoptosis in OC cells and thus further inhibited the growth of OC cells evaluated using flow cytometry (p < 0.05). The underlying mechanism of the suppressing effects of SPUP might be related to the inhibition of the hedgehog (Hh) signaling pathway in OC cells after SPUP treatment. With additional suppression of the Hh signaling pathway, the anticancer effects of SPUP were enhanced (p < 0.05).Conclusion: Taken together, SPUP could inhibit the proliferation, migration, and invasion and induce apoptosis of OC cells by inhibiting the activation of the Hh signaling pathway, which proposes SPUP as a novel drug to treat OC clinically.

Localised population collapse of the invasive brown alga, Undaria pinnatifida: Twenty years of monitoring on Wellington's south coast

<p>Invasive species pose a significant threat to marine environments around the world. Monitoring and research of invasive species is needed to provide direction for management programmes. This thesis is a continuation of research conducted on the invasive alga Undaria pinnatifida following its discovery on Wellington’s south coast in 1997. By compiling the results from previous monitoring surveys (1997-2000 and 2008) and carrying out additional seasonal surveys in 2018, I investigate the distribution and spread of U. pinnatifida on Wellington’s south coast, how this may have changed over time and what impacts it may have had on native macroalgal and invertebrate grazer communities. Intertidal macroalgal composition and U. pinnatifida abundance was recorded on fifteen occasions between 1997 and 2018 at two sites at Island Bay and two sites at Owhiro Bay. In addition, the subtidal abundance of six invertebrate grazers was recorded eight times within the same sampling period. Microtopography was also measured at each site to determine if topography had an influence on macroalgal composition. From 1997 to 2000 U. pinnatifida abundance gradually increased per year, but its spread remained localised to Island Bay. In 2008 U. pinnatifida had spread westward to Owhiro Bay where it was highly abundant. However, in 2018 no U. pinnatifida was recorded at any of the sites indicating a collapse of the invasion front. Further investigation revealed that U. pinnatifida was still present along the south coast with the nearest population only 500 m away from the nearest study site. The cause of the U. pinnatifida collapse is not known for certain, but it is unlikely that biotic resistance in the form of competitive exclusion or grazing or a change in environmental parameters such as temperature or nutrient concentration were contributing factors. It is speculated that the collapse arose from a multitude of confounding effects of which further research is needed to identify the exact cause. U. pinnatifida had no impact on macroalgal or grazer community composition. Additionally, microtopography also had no significant impact on macroalgal composition. This study reports the first ever invasion front collapse of U. pinnatifida in the world, and as a result, provides a new insight on U. pinnatifida distribution and invasion ecology. These findings can assist in predicting the future spread of U. pinnatifida populations as well as aid in formulation of new management strategies.</p>

Localised population collapse of the invasive brown alga, Undaria pinnatifida: Twenty years of monitoring on Wellington's south coast

<p>Invasive species pose a significant threat to marine environments around the world. Monitoring and research of invasive species is needed to provide direction for management programmes. This thesis is a continuation of research conducted on the invasive alga Undaria pinnatifida following its discovery on Wellington’s south coast in 1997. By compiling the results from previous monitoring surveys (1997-2000 and 2008) and carrying out additional seasonal surveys in 2018, I investigate the distribution and spread of U. pinnatifida on Wellington’s south coast, how this may have changed over time and what impacts it may have had on native macroalgal and invertebrate grazer communities. Intertidal macroalgal composition and U. pinnatifida abundance was recorded on fifteen occasions between 1997 and 2018 at two sites at Island Bay and two sites at Owhiro Bay. In addition, the subtidal abundance of six invertebrate grazers was recorded eight times within the same sampling period. Microtopography was also measured at each site to determine if topography had an influence on macroalgal composition. From 1997 to 2000 U. pinnatifida abundance gradually increased per year, but its spread remained localised to Island Bay. In 2008 U. pinnatifida had spread westward to Owhiro Bay where it was highly abundant. However, in 2018 no U. pinnatifida was recorded at any of the sites indicating a collapse of the invasion front. Further investigation revealed that U. pinnatifida was still present along the south coast with the nearest population only 500 m away from the nearest study site. The cause of the U. pinnatifida collapse is not known for certain, but it is unlikely that biotic resistance in the form of competitive exclusion or grazing or a change in environmental parameters such as temperature or nutrient concentration were contributing factors. It is speculated that the collapse arose from a multitude of confounding effects of which further research is needed to identify the exact cause. U. pinnatifida had no impact on macroalgal or grazer community composition. Additionally, microtopography also had no significant impact on macroalgal composition. This study reports the first ever invasion front collapse of U. pinnatifida in the world, and as a result, provides a new insight on U. pinnatifida distribution and invasion ecology. These findings can assist in predicting the future spread of U. pinnatifida populations as well as aid in formulation of new management strategies.</p>

Extending the Cultivation Period of Undaria pinnatifida by Using Regional Strains with Phenotypic Differentiation along the Sanriku Coast in Northern Japan

The Sanriku district is one of the largest Undaria pinnatifida (Wakame) cultivation areas in Japan. However, the production has steadily declined in recent years due to the high retirement rate among fishers. Extending the cultivation period is a potential way to improve productivity by decentralizing the workforce through the production process. We aimed to investigate the phenotypic differentiation between regional strains of U. pinnatifida collected from Matsushima Bay (MAT) and Hirota Bay (HRT) in the Sanriku district through a cultivation trial to verify the application for the purpose of extending the cultivation period. The growth of MAT was better than that of HRT when the cultivation started earlier (i.e., 9 and 19 October 2014); in contrast, HRT outperformed MAT when the cultivation started later (6 November and 12 December 2014). The yield of MAT reached over the standard amount in the Sanriku district in February. On the other hand, the yield of HRT reached over this value in April. Furthermore, the photosynthetic performance and nutrient uptake rates differed between MAT and HRT, indicating that the differences may result in maturation characteristics. According to these results, the combined use of MAT and HRT would be a valuable strategy by which to extend the cultivation period.

Breeding in the Economically Important Brown Alga Undaria pinnatifida: A Concise Review and Future Prospects

Undaria pinnatifida is the commercially second most important brown alga in the world. Its global annual yield has been more than two million tonnes since 2012. It is extensively cultivated in East Asia, mainly consumed as food but also used as feed for aquacultural animals and raw materials for extraction of chemicals applicable in pharmaceutics and cosmetics. Cultivar breeding, which is conducted on the basis of characteristics of the life history, plays a pivotal role in seaweed farming industry. The common basic life history shared by kelps determines that their cultivar breeding strategies are similar. Cultivar breeding and cultivation methods of U. pinnatifida have usually been learned or directly transferred from those of Saccharina japonica. However, recent studies have revealed certain peculiarity in the life history of U. pinnatifida. In this article, we review the studies relevant to cultivar breeding in this alga, including the peculiar component of the life history, and the genetics, transcriptomics and genomics tools available, as well as the main cultivar breeding methods. Then we discuss the prospects of cultivar breeding based on our understanding of this kelp and what we can learn from the model brown alga and land crops.