Wound closure is a critical step in postoperative wound recovery. Substantial advancements have been made in many different means of facilitating wound closure, including the use of tissue adhesives. ...Compared to conventional methods, such as suturing, tissue bioadhesives better accelerate wound closure. However, several existing tissue adhesives suffer from cytotoxicity, inadequate tissue adhesive strength, and high costs. In this study, a series of bioadhesives was produced using non-swellable spider silk-derived silk fibroin protein and an outer layer of swellable polyethylene glycol and tannic acid. The gelation time of the spider silk-derived silk fibroin protein bioadhesive is less than three minutes and thus can be used during rapid surgical wound closure. By adding polyethylene glycol (PEG) 2000 and tannic acid as co-crosslinking agents to the N-Hydroxysuccinimide (NHS), and 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) reaction, the adhesive strength of the bioadhesive became 2.5 times greater than that of conventional fibrin glue adhesives. Silk fibroin bioadhesives do not show significant cytotoxicity in vitro compared with other bioadhesives. In conclusion, silk fibroin bioadhesive is promising as a new medical tool for more effective and efficient surgical wound closure, particularly in bone fractures.
Abstract
We aimed to determine the effects of deep learning-based reconstruction (DLR) on radiomic features obtained from cardiac computed tomography (CT) by comparing with iterative reconstruction ...(IR), and filtered back projection (FBP). A total of 284 consecutive patients with 285 cardiac CT scans that were reconstructed with DLR, IR, and FBP, were retrospectively enrolled. Radiomic features were extracted from the left ventricular (LV) myocardium, and from the periprosthetic mass if patients had cardiac valve replacement. Radiomic features of LV myocardium from each reconstruction were compared using a fitting linear mixed model. Radiomics models were developed to diagnose periprosthetic abnormality, and the performance was evaluated using the area under the receiver characteristics curve (AUC). Most radiomic features of LV myocardium (73 of 88) were significantly different in pairwise comparisons between all three reconstruction methods (
P
< 0.05). The radiomics model on IR exhibited the best diagnostic performance (AUC 0.948, 95% CI 0.880–1), relative to DLR (AUC 0.873, 95% CI 0.735–1) and FBP (AUC 0.875, 95% CI 0.731–1), but these differences did not reach significance (
P
> 0.05). In conclusion, applying DLR to cardiac CT scans yields radiomic features distinct from those obtained with IR and FBP, implying that feature robustness is not guaranteed when applying DLR.
Artificial bone substitutes have been developed using various biomaterials for use in medicine. Silk fibroin (SF) displays excellent mechanical properties and cell compatibility. Nonetheless, the ...mechanical properties of silk fibroin scaffolds used in artificial bone substitutes are weaker than those of natural bone, and silk fibroin is deficient as an osteogenic agent. This limits their effectiveness in bone tissue engineering. We added nano-hydroxyapatite (nHAp) particles to an existing cell-based artificial bone substitute with a silk fibroin scaffold, which will improve its mechanical properties and osteogenic efficacy, leading to significant bone regeneration. The mechanical characters of silk fibroin modifying with nHAp were measured by Atomic Force Microscopy Analysis, dispersive x-ray spectroscopy, Porosity measurement, and Microcomputed Tomography. The proliferation and toxicity of a fibroin/dextran/collagen sponge (FDS) containing nHAp were evaluated
, and its osteogenic efficacy was evaluated using nude mouse and rabbit radius defect models. The defect area was repaired and showed callus formation of new bone in the rabbit radius defect models of the nHAp-FDS-treated group, whereas the defect area was unchanged in the FDS-treated group. The nHAp-FDS manufactured in this study showed significant bone regeneration owing to the synergistic effects of the components, such as those due to the broad range of pore sizes in the sponge and protein adsorbability of the nHAp, which could be suggested as a better supportive material for bone tissue engineering.
In various geological settings, alunite supergroup minerals, including the end members alunite KAl3(SO4)2(OH)6 and jarosite KFe3(SO4)2(OH)6, occur in extensive solid solution on the cation and anion ...sites, enabling them to accommodate a variety of elements. Jarosite is known for scavenging heavy metals on the K site (e.g., Pb in solid solution between jarosite and plumbojarosite) in acid mine drainage settings, while both jarosite and alunite can be important in controlling toxic anions such as selenate, chromate, or arsenate. However, there is no thermodynamic information on the solubility of these important cations and anions as a function of temperature, in part because this information is difficult to obtain experimentally. In this study, thermodynamic mixing properties of sulfate-chromate (S-Cr), sulfate-selenate (S-Se), and sulfate-phosphate-arsenate (S-P-As) solid solutions in alunite supergroup minerals are investigated based on quantum-mechanical modeling and statistical thermodynamic analysis.
S-Cr and S-Se solid solutions in alunite and jarosite are due to the mixing of anions with equivalent charges on the sulfate site. The enthalpy of mixing (ΔHmix) is lowest at 0 K (−273 °C) and increases with increasing temperature; it also depends on the arrangement of atoms on the sulfate site (i.e., atomic ordering). ΔHmix is almost constant at −70 °C and higher temperatures. These findings imply that S-Cr and S-Se solid solutions tend to be complete at room temperature and no ordering is acquired at or above ambient conditions. The Gibbs free energy of mixing (ΔGmix) indicates that jarosite is more flexible to accommodate chromate and selenate at the sulfate site than the alunite structure and that complete solid solution can be formed between jarosite and both Se- and Cr-analogues at temperatures above −80 °C. Our modeling results of solid solutions in jarosite and alunite demonstrate the critical role of alunite supergroup minerals in controlling toxic elements for long-term immobilization including the relatively favorable incorporation of uranyl (UO22+) into plumbojarosite.
The S-P-As solid solution is also explored between alunite family minerals DAl3(TO4)2(OH, H2O)6 (D is K+, Na+ or Ca2+; TO4 is SO42−, PO43− or AsO43−). The energetic barrier for mixing (reflected by the peak enthalpy of mixing) between ions with different charges (i.e., S-P and As-S solid solution; ∼2–3 kJ/mol of exchangeable atoms) is higher by a factor of two or three compared to anions with the equal charge (P-As solid solution; 1–1.5 kJ/mol of exchangeable atoms). Below 700 °C, ternary S-P-As mixing over a range of compositions in ternary space having alunite, crandallite CaAl3(PO4)6(OH)5(H2O), and arsenocrandallite CaAl3(AsO4)6(OH)5(H2O) as end members shows large miscibility gaps at compositions close to the ratio of S:P:As = 4:1:1 and 1:1:1 at the TO4 site. Ternary S-P-As mixing between woodhouseite, arsenowoodhouseite, and either alunite or natroalunite shows that arsenate is more compatible with sulfate in natroalunite than sulfate in alunite, whereas substitution of sulfate with phosphate is energetically more favorable in alunite than natroalunite. Our computed phase diagrams of S-P-As mixing suggest that binary solid solutions between pairs of sulfate, phosphate and arsenate in alunite family minerals scarcely occur below 100 °C, is limited at temperatures from 100 to 300 °C and become extensive or complete above 300 °C.
