Frog nest foams exhibit pharmaceutical foam-like properties.

Foams have frequently been used as systems for the delivery of cosmetic and therapeutic molecules; however, there is high variability in the foamability and long-term stability of synthetic foams. The development of pharmaceutical foams that exhibit desirable foaming properties, delivering appropriate amounts of the active pharmaceutical ingredient (API) and that have excellent biocompatibility is of great interest. The production of stable foams is rare in the natural world; however, certain species of frogs have adopted foam production as a means of providing a protective environment for their eggs and larvae from predators and parasites, to prevent desiccation, to control gaseous exchange, to buffer temperature extremes, and to reduce UV damage. These foams show great stability (up to 10 days in tropical environments) and are highly biocompatible due to the sensitive nature of amphibian skin. This work demonstrates for the first time that nests of the túngara frog (Engystomops pustulosus) are stable ex situ with useful physiochemical and biocompatible properties and are capable of encapsulating a range of compounds, including antibiotics. These protein foam mixtures share some properties with pharmaceutical foams and may find utility in a range of pharmaceutical applications such as topical drug delivery systems.

Awakening ancient polar Actinobacteria: diversity, evolution and specialized metabolite potential.

Polar and subpolar ecosystems are highly vulnerable to global climate change with consequences for biodiversity and community composition. Bacteria are directly impacted by future environmental change and it is therefore essential to have a better understanding of microbial communities in fluctuating ecosystems. Exploration of Polar environments, specifically sediments, represents an exciting opportunity to uncover bacterial and chemical diversity and link this to ecosystem and evolutionary parameters. In terms of specialized metabolite production, the bacterial order Actinomycetales, within the phylum Actinobacteria are unsurpassed, producing 10 000 specialized metabolites accounting for over 45 % of all bioactive microbial metabolites. A selective isolation approach focused on spore-forming Actinobacteria of 12 sediment cores from the Antarctic and sub-Arctic generated a culture collection of 50 strains. This consisted of 39 strains belonging to rare Actinomycetales genera including Microbacterium, Rhodococcus and Pseudonocardia. This study used a combination of nanopore sequencing and molecular networking to explore the community composition, culturable bacterial diversity, evolutionary relatedness and specialized metabolite potential of these strains. Metagenomic analyses using MinION sequencing was able to detect the phylum Actinobacteria across polar sediment cores at an average of 13 % of the total bacterial reads. The resulting molecular network consisted of 1652 parent ions and the lack of known metabolite identification supports the argument that Polar bacteria are likely to produce previously unreported chemistry.

Electrospun collagen-based nanofibres: A sustainable material for improved antibiotic utilisation in tissue engineering applications.

For the creation of scaffolds in tissue engineering applications, it is essential to control the physical morphology of fibres and to choose compositions which do not disturb normal physiological function. Collagen, the most abundant protein in the human body, is a well-established biopolymer used in electrospinning compositions. It shows high in-vivo stability and is able to maintain a high biomechanical strength over time. In this study, the effects of collagen type I in polylactic acid-drug electrospun scaffolds for tissue engineering applications are examined. The samples produced were subsequently characterised using a range of techniques. Scanning electron microscopy analysis shows that the fibre morphologies varied across PLA-drug and PLA-collagen-drug samples - the addition of collagen caused a decrease in average fibre diameter by nearly half, and produced nanofibres. Atomic force microscopy imaging revealed collagen-banding patterns which show the successful integration of collagen with PLA. Solid-state characterisation suggested a chemical interaction between PLA and drug compounds, irgasan and levofloxacin, and the collagen increased the amorphous regions within the samples. Surface energy analysis of drug powders showed a higher dispersive surface energy of levofloxacin compared with irgasan, and contact angle goniometry showed an increase in hydrophobicity in PLA-collagen-drug samples. The antibacterial studies showed a high efficacy of resistance against the growth of both E. coli and S. Aureus, except with PLA-collagen-LEVO which showed a regrowth of bacteria after 48h. This can be attributed to the low drug release percentage incorporated into the nanofibre during the in vitro release study. However, the studies did show that collagen helped shift both drugs into sustained release behaviour. These ideal modifications to electrospun scaffolds may prove useful in further research regarding the acceptance of human tissue by inhibiting the potential for bacterial infection.

Draft Genome Sequence of Plant Growth-Promoting Endophytic Streptomyces sp. GKU 895 Isolated from the Roots of Sugarcane.

Streptomyces sp. GKU 895 is an endophytic actinomycete isolated from the roots of sugarcane. GKU 895 has a genome of 8.3 Mbp and the genome exhibits adaptations related to plant growth-promoting activity. It also has extensive specialized metabolite biosynthetic gene clusters apparent in its genome.

Development and Application of an eDNA Method to Detect the Critically Endangered Trinidad Golden Tree Frog (Phytotriades auratus) in Bromeliad Phytotelmata.

The use of environmental DNA (eDNA) to monitor rare and elusive species has great potential for conservation biology. Traditional surveying methods can be time-consuming, labour-intensive, subject to error or can be invasive and potentially damaging to habitat. The Trinidad golden treefrog (Phytotriades auratus) is one such species that would benefit from such an approach. This species inhabits the giant bromeliad (Glomeropitcairnia erectiflora) on two peaks on the Caribbean island of Trinidad. Traditional survey methods for this species have required the destruction of the giant bromeliad, which is the only known habitat of this frog. Here we described the development of an eDNA PCR-based assay that uses water drawn from the water-filled phytotelmata of the giant bromeliad along with the use of a synthetic DNA positive control that can be easily amplified in the bacterium Escherichia coli. The assay can detect to a DNA concentration of 1.4ng. Sampling of 142 bromeliads using this method revealed 9% were positive for P. auratus DNA. These data suggest that eDNA methods also have great potential for revealing the presence of elusive species in arboreal habitats.

Fabrication and characterisation of drug-loaded electrospun polymeric nanofibers for controlled release in hernia repair.

The chemical distribution and mechanical effects of drug compounds in loaded electrospun scaffolds, a potential material for hernia repair mesh, were characterised and the efficacy of the material was evaluated. Polycaprolactone electrospun fibres were loaded with either the antibacterial agent, irgasan, or the broad-spectrum antibiotic, levofloxacin. The samples were subsequently characterised by rheological studies, scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle goniometry (CAG), in vitro drug release studies, antibacterial studies and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Increased linear viscoelastic regions observed in the rheometry studies suggest that both irgasan and levofloxacin alter the internal structure of the native polymeric matrix. In vitro drug release studies from the loaded polymeric matrix showed significant differences in release rates for the two drug compounds under investigation. Irgasan showed sustained release, most likely driven by molecular diffusion through the scaffold. Conversely, levofloxacin exhibited a burst release profile indicative of phase separation at the edge of the fibres. Two scaffold types successfully inhibited bacterial growth when tested with strains of E. coli and S. aureus. Electrospinning drug-loaded polyester fibres is an alternative, feasible and effective method for fabricating non-woven fibrous meshes for controlled release in hernia repair.