Polymer Materials for Oral and Craniofacial Tissue Engineering
Vincenzo Guarino, Marco Antonio Alvarez-Pérez in Current Advances in Oral and Craniofacial Tissue Engineering, 2020
Silk fibroin is a natural fiber protein that has gained attention for biomedical applications requiring an improvement of mechanical properties (i.e., flexibility and high tensile strength). Silk fibers extracted from domesticated silkworm Bombix mori (B. mori) are the best characterized. The amino acid composition of silk consists of glycine, alanine, serine (Vepari and Kaplan 2007; Ma et al. 2018). Silk is composed of a filament core coated with sericin, a hydrophilic protein. Sericin is degummed during the silk purification process leaving the core fibers corresponding to silk. For tissue engineering applications, silk fibroin has shown to have better mechanical properties than other natural polymers, excellent biocompatibility and its degradation products are non-toxic (Bai et al. 2015).
Degradable, biodegradable, and bioresorbable polymers for time-limited therapy
Yoshinobu Onuma, Patrick W.J.C. Serruys in Bioresorbable Scaffolds, 2017
Silks are fibrous proteins composed of glycine, serine, and alanine. Their molecular structures are rather complex and depend on their origin. The outstanding strength of silk fibers comes from the presence of a number of crystalline domains separated by disordered ones. In practice, silk fibroin is purified from sericin. As most of polymeric compounds derived from biopolymers, silks can be processed to gels, films, sponges, and also chemically modified. Silk proteins degrade via the action of proteases, like any protein. The degradation by-products of silk are peptides and amino acids. The rate of silk fibroin degradation depends on structure, morphology, and mechanical and biological conditions at the location of implantation. The degradation of silk-based polymeric compounds by enzymes is well documented in vitro where degradation is rather fast. Much less information is available for in vivo degradation where fibroin-based materials seem to fragment with variable fragmentation times. Many applications are proposed [30].
Natural Products and Stem Cells and Their Commercial Aspects in Cosmetics
Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters in Cosmetic Formulation, 2019
Silk is an ingredient that was discovered in China and has been used in various industries for thousands of years. Silk is a filament secreted by silkworms of Bombyx mori silk moths. Silk is comprised of about 25–30% sericin, a sticky material that surrounds the fibroin protein that is found in the center of silk. Traditionally, sericin had been degummed from silk, and its disposal caused environmental concerns, particularly water pollution. Sericin is primarily composed of the amino acid serine, and the protein has antibacterial, antioxidant, irritation-reducing and moisturizing properties (Barel et al., 2014). Ground silk proteins can be used in facial powders and foundations, and can also improve hair texture and shine (Corbeil et al., 2000).
Response surface optimization of enzymatic hydrolysis and ROS scavenging activity of silk sericin hydrolysates
Published in Pharmaceutical Biology, 2022
Keerati Joyjamras, Chatchai Chaotham, Pithi Chanvorachote
The rapid expansion of industries to supply consumable products globally unavoidably causes ecological problems (Zhu et al. 2019). Without proper management, sericin protein present in the degumming water used in silk processing results in a high level of chemical oxygen demand (COD), which contributes to water pollution (Pakdel et al. 2016). In seeking to recycle the wastewater from silk production, several researchers have discovered the potential benefits of silk sericin (Kunz et al. 2016; Cao and Zhang 2017; Liu et al. 2020). Silk protein, which is produced from Bombyx mori Linnaeus (Bombycidae) comprises 25–30% sericin protein wrapped around fibroin fibre (Jena et al. 2018). The globular structure of water-soluble sericin consists of diverse amino acids, among which serine, histidine, glycine, threonine, tyrosine, aspartate and glutamine are predominant (Kunz et al. 2016). Recently, several biological functions of sericin have been reported, including antioxidant activity (Ersel et al. 2016; Ampawong et al. 2017; Manesa et al. 2020).
Enhanced transdermal insulin basal release from silk fibroin (SF) hydrogels via iontophoresis
Published in Drug Delivery, 2022
Phimchanok Sakunpongpitiporn, Witthawat Naeowong, Anuvat Sirivat
To remove sericin, 2 g silk cocoon was boiled in a 0.5 g Na2CO3 solution for 30 min and then the solution was rinsed with distilled water (Hu et al., 2012). The process was repeated three times. After that, the degummed silk was dried at room temperature (27 ± 1 °C) to obtain a silk fibroin (SF) fiber. The 20 g degummed silk fiber was slowly added (1 g at a time) and it was dissolved in a ternary solvent of the CaCl2: H2O: C2H5OH 1: 8: 2 mole ratio at 80 °C for 4 hours (Kim & Park, 2016). The solution was dialyzed in distilled water with a snakeskin dialysis tubing for 3 days. The solution was centrifuged at 8000 rpm to remove impurities (Kuang et al., 2018) to obtain the SF solution. The degumming process (removal of sericin) was confirmed by the FTIR technique.
Sericin-mediated improvement of dysmorphic cardiac mitochondria from hypercholesterolaemia is associated with maintaining mitochondrial dynamics, energy production, and mitochondrial structure
Published in Pharmaceutical Biology, 2022
Kitiya Rujimongkon, Sumate Ampawong, Duangnate Isarangkul, Onrapak Reamtong, Pornanong Aramwit
Sericin is a natural molecule found in the silkworm Bombyx mori Linnaeus (Bombycidae) cocoon and possesses various biochemical properties, including antityrosinase, anti-lipid peroxidation, and antioxidant activities (Kato et al. 1998; Dash et al. 2008; Aramwit et al. 2010a, 2010b; Takechi et al. 2014). Several methods, including urea, citric acid, sodium carbonate, and high temperature coupled with high-pressure extraction, have been used to characterise the amino acid content, structure, and biochemical properties of sericin (Aramwit et al. 2010a). Sericin has been used in several biomedical applications, such as for wound healing and as a biomaterial essential for tissue engineering (Aramwit and Sangcakul 2007; Aramwit et al. 2013; Lamboni et al. 2015). Sericin extracted using high-temperature and high-pressure methods have been used as a food supplement and have been shown to be able to significantly reduce serum cholesterol in a hypercholesterolemic rat model (Ampawong et al. 2017a, 2017b).