Although three-dimensional (3D) bioprinting technology has gained much attention in the field of tissue engineering, there are still several significant engineering challenges to overcome, including ...lack of bioink with biocompatibility and printability. Here, we show a bioink created from silk fibroin (SF) for digital light processing (DLP) 3D bioprinting in tissue engineering applications. The SF-based bioink (Sil-MA) was produced by a methacrylation process using glycidyl methacrylate (GMA) during the fabrication of SF solution. The mechanical and rheological properties of Sil-MA hydrogel proved to be outstanding in experimental testing and can be modulated by varying the Sil-MA contents. This Sil-MA bioink allowed us to build highly complex organ structures, including the heart, vessel, brain, trachea and ear with excellent structural stability and reliable biocompatibility. Sil-MA bioink is well-suited for use in DLP printing process and could be applied to tissue and organ engineering depending on the specific biological requirements.
The development of biocompatible and precisely printable bioink addresses the growing demand for three-dimensional (3D) bioprinting applications in the field of tissue engineering. We developed a ...methacrylated photocurable silk fibroin (SF) bioink for digital light processing 3D bioprinting to generate structures with high mechanical stability and biocompatibility for tissue engineering applications. Procedure 1 describes the synthesis of photocurable methacrylated SF bioink, which takes 2 weeks to complete. Digital light processing is used to fabricate 3D hydrogels using the bioink (1.5 h), which are characterized in terms of methacrylation, printability, mechanical and rheological properties, and biocompatibility. The physicochemical properties of the bioink can be modulated by varying photopolymerization conditions such as the degree of methacrylation, light intensity, and concentration of the photoinitiator and bioink. The versatile bioink can be used broadly in a range of applications, including nerve tissue engineering through co-polymerization of the bioink with graphene oxide, and for wound healing as a sealant. Procedure 2 outlines how to apply 3D-printed SF hydrogels embedded with chondrocytes and turbinate-derived mesenchymal stem cells in one specific in vivo application, trachea tissue engineering, which takes 2-9 weeks.
Several methods for auricular cartilage engineering use tissue engineering techniques. However, an ideal method for engineering auricular cartilage has not been reported. To address this issue, we ...developed a strategy to engineer auricular cartilage using silk fibroin (SF) and polyvinyl alcohol (PVA) hydrogel. We constructed different hydrogels with various ratios of SF and PVA by using salt leaching, silicone mold casting, and freeze-thawing methods. We characterized each of the hydrogels in terms of the swelling ratio, tensile strength, pore size, thermal properties, morphologies, and chemical properties. Based on the cell viability results, we found a blended hydrogel composed of 50% PVA and 50% SF (P50/S50) to be the best hydrogel among the fabricated hydrogels. An intact 3D ear-shaped auricular cartilage formed six weeks after the subcutaneous implantation of a chondrocyte-seeded 3D ear-shaped P50/S50 hydrogel in rats. We observed mature cartilage with a typical lacunar structure both in vitro and in vivo via histological analysis. This study may have potential applications in auricular tissue engineering with a human ear-shaped hydrogel.
Three-dimensional printing with Digital Lighting Processing (DLP) printer has come into the new wave in the tissue engineering for regenerative medicine. Especially for the clinical application, it ...needs to develop of bio-ink with biocompatibility, biodegradability and printability. Therefore, we demonstrated that Silk fibroin as a natural polymer fabricated with glycidyl-methacrylate (Silk-GMA) for DLP 3D printing. The ability of chondrogenesis with chondrocyte-laden Silk-GMA evaluated in vitro culture system and applied in vivo. DLP 3D printing system provided 3D product with even cell distribution due to rapid printing speed and photopolymerization of DLP 3D printer. Up to 4 weeks in vitro cultivation of Silk-GMA hydrogel allows to ensure of viability, proliferation and differentiation to chondrogenesis of encapsulated cells. Moreover, in vivo experiments against partially defected trachea rabbit model demonstrated that new cartilage like tissue and epithelium found surrounding transplanted Silk-GMA hydrogel. This study promises the fabricated Silk GMA hydrogel using DLP 3D printer could be applied to the fields of tissue engineering needing mechanical properties like cartilage regeneration.
Recently, four-dimensional (4D) printing is emerging as the next-generation biofabrication technology. However, current 4D bioprinting lacks biocompatibility or multi-component printability. In ...addition, suitable implantable targets capable of applying 4D bioprinted products have not yet been established, except theoretical and in vitro study. Herein, we describe a cell-friendly and biocompatible 4D bioprinting system including more than two cell types based on digital light processing (DLP) and photocurable silk fibroin (Sil-MA) hydrogel. The shape changes of 3D printed bilayered Sil-MA hydrogels were controlled by modulating their interior or exterior properties in physiological conditions. We used finite element analysis (FEA) simulations to explore the possible changes in the complex structure. Finally, we made trachea mimetic tissue with two cell types using this 4D bioprinting system and implanted it into a damaged trachea of rabbit for 8 weeks. The implants were integrated with the host trachea naturally, and both epithelium and cartilage were formed at the predicted sites. These findings demonstrate that 4D bioprinting system could make tissue mimetic scaffold biologically and suggest the potential value of the 4D bioprinting system for tissue engineering and the clinical application.
Reduced graphene oxide (rGO) has wide application as a nanofiller in the fabrication of electroconductive biocomposites due to its exceptional properties. However, the hydrophobicity and chemical ...stability of rGO limit its ability to be incorporated into precursor polymers for physical mixing during biocomposite fabrication. Moreover, until now, no suitable rGO-combining biomaterials that are stable, soluble, biocompatible, and 3D printable have been developed. In this study, we fabricated digital light processing (DLP) printable bioink (SGOB1), through covalent reduction of graphene oxide (GO) by glycidyl methacrylated silk fibroin (SB). Compositional analyses showed that SGOB1 contains approximately 8.42% GO in its reduced state. Our results also showed that the rGO content of SGOB1 became more thermally stable and highly soluble. SGOB1 hydrogels demonstrated superior mechanical, electroconductive, and neurogenic properties than (SB). Furthermore, the photocurable bioink supported Neuro2a cell proliferation and viability. Therefore, SGOB1 could be a suitable biocomposite for neural tissue engineering.
Three-dimensional (3D) bioprinting has been developed as a viable method for fabricating functional tissues and organs by precisely spatially arranging biomaterials, cells, and biochemical components ...in a layer-by-layer fashion. Among the various bioprinting strategies, digital light-processing (DLP) printing has gained enormous attention due to its applications in tissue engineering and biomedical fields. It allows for high spatial resolution and the rapid printing of complex structures. Although bio-ink is a critical aspect of 3D bioprinting, only a few bio-inks have been used for DLP bioprinting in contrast to the number of bio-inks employed for other bioprinters. Recently, silk fibroin (SF), as a natural bio-ink material used for DLP 3D bioprinting, has gained extensive attention with respect to biomedical applications due to its biocompatibility and mechanical properties. This review introduces DLP-based 3D bioprinting, its related technology, and the fabrication process of silk fibroin-based bio-ink. Then, we summarize the applications of DLP 3D bioprinting based on SF-based bio-ink in the tissue engineering and biomedical fields. We also discuss the current limitations and future perspectives of DLP 3D bioprinting using SF-based bio-ink.
Silk Fibroin in Wound Healing Process Sultan, Md Tipu; Lee, Ok Joo; Kim, Soon Hee ...
Advances in experimental medicine and biology,
2018, Letnik:
1077
Journal Article
Recenzirano
Silk fibroin (SF), a natural bioproduct, has been extensively used in biological and biomedical fields including wound healing due to its robust biocompatibility, less immunogenic, non-toxic, ...non-carcinogenic, and biodegradable properties. SF in different morphologic forms, such as hydrogels, sponges, films, electrospun nanofiber mats, and hydrocolloid dressings, have been successfully used for therapeutic use as wound dressings to induce the healing process. SF has also been known to promote wound healing by increasing the cell growth, proliferation, and migration of different cells types involved in the different phase of wound healing process. In this review, we summarize the different morphologic forms of SF that have been used in the treatment of various wound healing process. We also discuss the effect of SF on various cells types during the SF-induced healing process. Furthermore, we highlight molecular signaling aspects of the SF-induced healing process.
Hemostasis plays an essential role in all surgical procedures. Uncontrolled hemorrhage is the primary cause of death during surgeries, and effective blood loss control can significantly reduce ...mortality. For modern surgeons to select the right agent at the right time, they must understand the mechanisms of action, the effectiveness, and the possible adverse effects of each agent. Over the past decade, various hemostatic agents have grown intensely. These agents vary from absorbable topical hemostats, including collagen, gelatins, microfibrillar, and regenerated oxidized cellulose, to biologically active topical hemostats such as thrombin, biological adhesives, and other combined agents. Commercially available products have since expanded to include topical hemostats, surgical sealants, and adhesives. Silk is a natural protein consisting of fibroin and sericin. Silk fibroin (SF), derived from silkworm
, is a fibrous protein that has been used mostly in fashion textiles and surgical sutures. Additionally, SF has been widely applied as a potential biomaterial in several biomedical and biotechnological fields. Furthermore, SF has been employed as a hemostatic agent in several studies. In this review, we summarize the several morphologic forms of SF and the latest technological advances on the use of SF-based hemostatic agents.
Sealants are useful as agents that can prevent the leakage of gas or nonclotting fluids from damaged tissues and of blood from the vascular system following injury or repair. Various formulations for ...sealants have been developed and applied clinically, but problems still remain in terms of biocompatibility issues, long crosslinking times and low adhesive properties. Herein, to address these issues, we report a methacrylated silk fibroin sealant (Sil-MAS) with rapidly crosslinkable, highly adhesive and biocompatible properties and demonstrate its versatility as a medical glue. The excellent physical properties of Sil-MAS are revealed via in vitro mechanical tests and ex vivo aorta pressure tests. In addition, in in vivo biological tests on the skin, liver, and blood vessels of rats, Sil-MAS showed a superb hemostatic and adhesive ability, with high biocompatibility. Specifically, Sil-MAS strongly contributed to faster wound healing than commercially available materials. Furthermore, we showed a successful proof of concept that Sil-MAS could serve as an ideal photocuring laparoscopic medical glue in a laceration rabbit model of liver and stomach serosa using a homemade endoscopic device. These findings on the applicability of rapidly photocurable silk fibroin indicate that Sil-MAS is a suitable material to supplant existing sealants, adhesives, or hemostatic agents.Biomaterials: Medical glue from a silk proteinAn efficient, fast-acting and biocompatible glue for sealing damaged body tissue has been developed by scientists in South Korea and the USA. The ability to stop bleeding is crucial in surgery. One solution is to use medical glues that can seal tissue and blood vessels. These glues need to be biocompatible, fast-acting, long-lasting and low cost. Many such sealants are now clinically available, but most do not meet all these requirements. Chan Hum Park from Hallym University in Chuncheon, South Korea, and co-workers developed a fast-acting, highly adhesive and biocompatible medical glue using a material derived from a silk protein. The team tested their methacrylated silk fibroin sealant on rat skin, liver and blood vessels and observed faster wound healing than that obtained using commercially available materials.
PDF
