11 research outputs found
Physicochemical and Biochemical Characterization of Collagen from <i>Stichopus</i> cf. <i>horrens</i> Tissues for Use as Stimuli-Responsive Thin Films
The mutable collagenous tissue (MCT) of sea cucumber,
with its
ability to rapidly change its stiffness and extensibility in response
to different environmental stress conditions, serves as inspiration
for the design of new smart functional biomaterials. Collagen, extracted
from the body wall of Stichopus cf. horrens, a species commonly found in the Philippines, was characterized
for its suitability as stimuli-responsive films. Protein BLAST search
showed the presence of sequences commonly found in type VII and IX
collagen, suggesting that Stichopus horrens collagen is heterotypic. The maximum transition temperature recorded
was 56.0 ± 2 °C, which is higher than those of other known
sources of marine collagen. This suggests that S. horrens collagen has better thermal stability and durability. Collagen-based
thin films were then prepared, and atomic force microscopy (AFM) imaging
showed the visible collagen network comprising the films. The thin
films were subjected to thermomechanical analysis with degradation
starting at >175 °C. At 100–150 °C, the collagen-based
films apparently lose their translucency due to the removal of moisture.
Upon exposure to ambient temperature, instead of degrading, the films
were able to revert to the original state due to the readsorption
of moisture. This study is a demonstration of a smart biomaterial
developed from S. cf. horrens collagen
with potential applications in food, pharmaceutical, biomedical, and
other collagen-based research
Molecular interactions driving the layer-by-layer assembly of multilayers
This article presents an overview of the different types of intermolecular interactions behind the fabrication of multilayer assemblies using the layer-by-layer (LbL) assembly approach. It comments on the potential impact of each type of intermolecular interaction and materials assembled through them on the development of advanced functional systems or devices for several emerging applications. The discussion begins with a brief overview of the most commonly used bottom-up methods to modify surfaces and fabricate functional multilayer thin films, with a special focus on their main advantages and disadvantages.This work received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. REGPOT-CT2012-316331-POLARIS. The work was also funded by FEDER through the Competitive Factors Operational Program (COMPETE) and by National funds through the Portuguese Foundation for Science and Technology (FCT) in the scope of the projects PTDC/FIS/115048/2009 and PTDC/CTM-BIO/1814/2012. The authors gratefully acknowledge Dr. Luca Gasperini (3B's Research Group, University of Minho, Portugal) for his help with the figures