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.

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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.

Objectives: To identify factors associated with positive margins following surgical management of sinonasal squamous cell carcinoma (SNSCC), especially with regard to endoscopic treatment.Methods: In a retrospective analysis of adult patients with clinically staged tumor (T)1 to T4a SNSCC within the National Cancer Database (NCDB) from 2004 to 2014, factors were associated with positive margins using multivariable binary logistic regression. Cases from 2010 to 2014 had surgical approach (open vs. endoscopic) available and were analyzed in a subgroup to assess the association of surgical approach with margin status. The association of margin status with overall survival (OS) and additional therapy administration was also assessed.Results: We identified 2,968 cases, of which 807 (27.2%) had positive margins. On multivariable analysis, factors associated with positive margins included higher T stage (T4a vs. T1: odds ratio [OR] 2.768 [95% CI 2.143-3.577]), less differentiated tumors (poorly differentiated vs. well differentiated: OR 1.403 [95% CI 1.060-1.856]), and tumors in the ethmoid sinus (vs. nasal cavity; OR 1.889 [95% CI 1.305-2.734]). Cases treated at higher volume facilities (HVFs) were associated with a lower likelihood of positive margins (OR 0.716 [95% CI 0.582-0.881]). Positive margins were associated with decreased OS (hazard ratio 1.672 [95% CI 1.464-1.908]) and an increased rate of additional therapy (OR 1.966 [95% confidence interval 1.597-2.421]). An endoscopic approach was not associated with an increased likelihood of obtaining positive margins (vs. open; OR 1.151 [0.903-1.651]).Conclusion: Positive margins were less likely when performed at HVFs and more likely in the ethmoid sinus than other subsites. Importantly, there was no association between positive margins and surgical approach. Endoscopic surgery may offer a safe, less invasive alternative to open surgery for select patients.

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Hydrocolloid dressings have been developed for many types of wound healing. In particular, dressing is a critical component in the successful recover of burn injuries, which causes a great number of people to not only suffer from physical but also psychological and economic anguish each year. Additionally, silk fibroin is the safest material for tissue engineering due to biocompatibility. In this study, we fabricated hydrocolloid dressings incorporating silk fibroin nanoparticles to enhance the efficacy of hydrocolloid dressing and then use this silk fibroin nanoparticle hydrocolloid dressing (SFNHD) in animal models to treat burn wounds. The structures and properties of SFN-HD were characterized using tensile strength and Cell Counting Kit-8 assay. The results indicated the structural stability and the cellular biocompatibility of the hydrocolloid dressing suggesting that SFNHD can be applied to the treatment of wounds. To demonstrate the capacity of a silk fibroin hydrocolloid dressing to treat burn wounds, we compared SFNHD to gauze and Neoderm ® , a commercially available dressing. This study clearly demonstrated accelerated wound healing with greater wound structural integrity and minimal wound size after treatment with SFNHD. These observations indicate that SFNHD may be an improvement upon current standard dressings such as Gauze and Neoderm ® for burn wounds.

Background Recessive mutations of coding regions and splice sites of the SLC26A4 gene cause hearing loss with enlargement of the vestibular aqueduct (EVA). Some patients also have a thyroid iodination defect that can lead to multinodular goiter as part of Pendred syndrome. A haplotype of variants upstream of SLC26A4 , called CEVA, acts as a pathogenic recessive allele in trans to mutations affecting the coding regions or splice sites of SLC26A4 . Our first hypothesis is that CEVA, acting as a pathogenic recessive allele, is correlated with a less severe phenotype than mutations affecting the coding regions and splice sites of SLC26A4 . Our second hypothesis is that CEVA acts as a modifier of the phenotype in patients with EVA caused by mutations affecting the coding regions or splice sites of both alleles of SLC26A4 or EVA caused by other factors. Methods This was a prospective cohort study of 114 individuals and 202 ears with EVA . To test our first hypothesis, we compared the thyroid and auditory phenotypes of subjects with mutations affecting coding regions of both alleles of SLC26A4 with those of subjects carrying CEVA in trans to mutations affecting the coding regions. To test our second hypothesis, we compared the phenotypes associated with the presence versus absence of CEVA among subjects with no coding region mutations, as well as among subjects with mutations affecting coding regions of both alleles. Results Subjects carrying CEVA in trans to a mutation of SLC26A4 have a normal thyroid phenotype and less severe hearing loss in comparison to individuals with mutations affecting coding regions of both alleles of SLC26A4 . In subjects with no mutant alleles of SLC26A4 , hearing loss was more severe in subjects who carry the CEVA haplotype in comparison to non-carriers. There was no correlation of CEVA with the phenotype of subjects with mutations affecting coding regions of both alleles. Conclusions CEVA, acting as a likely pathogenic recessive allele, is associated with a less severe phenotype than alleles with a mutation affecting the coding regions or splice sites of SLC26A4 . CEVA may act as a genetic modifier in patients with EVA caused by other factors.

The original version of this Article contained errors in Figs. 5 and 6. In Fig. 5b, the second panel on the bottom row was stretched out of proportion. In Fig. 6d, the first panel was also stretched out of proportion. In Fig. 6f, the fifth panel inadvertently repeated the fourth. This has been corrected in both the PDF and HTML versions of the Article.