The skin is a “barrier organ” that protects our bodies. The outermost layer, the stratum corneum, acts as a shield in both directions, preventing harmful environmental agents (pathogenic microorganisms, allergens, chemical substances) from entering, while limiting the release of water from our bodies. To carry out this important protective barrier function, the stratum corneum must maintain the proper hydrolipidic balance, (water content of 10-35% and fats). When this balance is disrupted due to disease, allergies or intolerances, or simply changes in climate, the use of aggressive detergents or cosmetics or wearing clothes that do to respect the skin (insufficient breathability and/or limited ability to absorb and release moisture, etc.), the stratum corneum changes (due to dehydration or conversely hyperhidrosis/maceration) and is no longer able to perform its protective function. This can lead to irritation, itchiness, dryness, inflammation and, in more serious cases, bacterial and fungal infections.
Over the past ten years, the scientific world’s interest in fibroin has grown enormously, with a focus on researching its unique properties, (which make it an “ideal candidate for use in the field of tissue engineering and the study of controlled drug release systems” (Altman GH, Diaz F, Jakuba C, Calabro T, Horan RL, Chen J, Lu H, Richmond J, Kaplan DL. Silk-based biomaterials. Biomaterials 2003; 24: 401-416):
Sericin has always been used as an essential component in the cosmetics industry since it has a unique affinity with other human proteins, enabling it to effectively bond with the keratin in skin and hair. It can create a multi-functional, moisturizing protective film and an anti-wrinkle protective film, leaving the skin feeling silky and providing significant aesthetic benefits.
The moisturizing effect is due primarily to formation of a film, without blocking:
Fights asthma, rhinitis and allergies
Tightly woven fibres, like those that can be obtained with silk, are the first barrier against acari colonization. Equally important is the correlation between imperviousness to acari allergens and the breathability of the fabric and/or fill. Airflow is essential not only from the perspective of the thermophysiological comfort of the silk product, but also for the health of the user. The moisture released from the body (for example, approximately 250-300 ml is released during the night), must move freely to the exterior environment not only because it can cause unpleasant odours but also because it can lead to rapid deterioration and an exponential increase in the growth of various species of fungi and moulds, which are the primary cause of asthma and rhinitis symptoms and, in some cases, can also cause allergies. Antimicrobial and antiallergenic treatments that do not release substances increase the excellent natural properties of silk.
But that’s not all:
Scientists at the Beijing Institute of Technology have discovered that fibroin from silk is able to increase the lifespan of lithium batteries by five times and improve their performance over time. Fibroin regenerated from natural silk works at a high level of performance for more than 10,000 cycles and stores more than five times more energy than graphite, the most utilized material for lithium battery anodes.
A biocompatible, biodegradable biopolymer derived from silk that can act as an optical fibre has been created by a group of researchers from Tufts University and the University of Illinois. Silk offers new opportunities for the creation of sensors with the potential to transport light to the interior of living tissues. Immediate applications include in vivo monitoring of glucose and the detection of viruses or Alzheimer markers.
A collaboration between the University of Pavia and Tufts University in Massachusetts has led to the creation of a three-dimensional system of tissue with silk microtubes that can reproduce the complex structure and physiology of human marrow and generate platelets. This technology could lead to customized medical treatments and the production of materials that can be transfused to patients.
A group of scientists at Tufts University in the United States has used water and silk proteins to produce three-dimensional biomaterials that have the unique ability to be programmed to carry out biological functions or release drugs.
A mixture of silkworm silk and Australian spider silk has produced a material that is five times stronger than steel and has excellent structural and acoustic properties tested by luthiers in Cremona.
Research published in Scientific Reports has shown that silk has a unique crystal structure that makes it one of the strongest materials in nature. Fibroin, an insoluble, biocompatible and biodegradable protein, can stabilize and protect other materials with which it comes into contact, acting as a sort of “protective shield” to preserve fruit. Analyses demonstrated that the silk coating protects the fruit by making it less permeable to oxygen and carbon dioxide;
In addition to being thinner than a strand of hair, it has the unique feature of being composed primarily of the silk protein fibroin. This micro-needle, described in the journal Advanced Functional Materials, is so small that it is not detected by nerve tissue and therefore does not cause discomfort.
Research published in the Proceedings of the National Academy of Sciences of the United States has revealed that fibroin functions as a stabilizer, preserving the efficacy of both vaccines and drugs, including when they are exposed to temperatures above 60 degrees. This function of the protein results from chains of amino acids that fold in specific shapes and are composed of crystal sheets that have numerous small pockets that trap the biomolecules and protect them from moisture and high temperatures. In practice, they function like bubble wrap on a nanometric scale. The most important consequences could be for developing countries in which limited infrastructure makes it difficult to keep these drugs refrigerated as required.