Long segmental repair of trachea stenosis is an intractable condition in the clinic. The reconstruction of an artificial substitute by tissue engineering is a promising approach to solve this unmet ...clinical need. 3D printing technology provides an infinite possibility for engineering a trachea. Here, we 3D printed a biodegradable reticular polycaprolactone (PCL) scaffold with similar morphology to the whole segment of rabbits' native trachea. The 3D-printed scaffold was suspended in culture with chondrocytes for 2 (Group I) or 4 (Group II) weeks, respectively. This in vitro suspension produced a more successful reconstruction of a tissue-engineered trachea (TET), which enhanced the overall support function of the replaced tracheal segment. After implantation of the chondrocyte-treated scaffold into the subcutaneous tissue of nude mice, the TET presented properties of mature cartilage tissue. To further evaluate the feasibility of repairing whole segment tracheal defects, replacement surgery of rabbits' native trachea by TET was performed. Following postoperative care, mean survival time in Group I was 14.38 ± 5.42 days, and in Group II was 22.58 ± 16.10 days, with the longest survival time being 10 weeks in Group II. In conclusion, we demonstrate the feasibility of repairing whole segment tracheal defects with 3D printed TET.
In the field of small-caliber vascular scaffold research, excellent vascular remodeling is the key to ensuring anticoagulant function. We prepared an off-the-shelf bi-layered vascular scaffold with a ...dense inner layer and a loose outer layer and evaluated its remodeling capabilities by in vivo transplantation.
Based on poly(L-lactide-co-ε-caprolactone) (PLCL), silk fibroin(SF), and heparin (Hep), PLCL/SF/Hep bi-layered scaffolds and PLCL/Hep bi-layered scaffolds were prepared by electrospinning. The inner layer was a PLCL/SF/Hep or PLCL/Hep nanofiber membrane, and the outer layer was PLCL/SF nano yarn. The in vitro tests included a hydrophilicity test, mechanical properties test, and blood and cell compatibility evaluation. The in vivo evaluation was conducted via single rabbit carotid artery replacement and subsequent examinations, including ultrasound imaging, immunoglobulin assays, and tissue section staining.
Compared to the PLCL/Hep nanofiber membrane, the hydrophilicity of the PLCL/SF/Hep nanofiber membrane was significantly improved. The mechanical strength met application requirements. Both the blood and cell compatibility were optimal. Most importantly, the PLCL/SF/Hep scaffolds maintained lumen patency for 3 months after carotid artery transplantation in live rabbits. At the same time, CD31 and α-SMA immunofluorescence staining confirmed bionic endothelial and smooth muscle layers remodeling.
Using this hybrid strategy, PLCL and SF were combined to manufacture bi-layered small-caliber vascular scaffolds; these PLCL/SF/Hep scaffolds showed satisfactory vascular remodeling.
Purpose: In the field of small-caliber vascular scaffold research, excellent vascular remodeling is the key to ensuring anticoagulant function. We prepared an off-the-shelf bi-layered vascular ...scaffold with a dense inner layer and a loose outer layer and evaluated its remodeling capabilities by in vivo transplantation. Materials and Methods: Based on poly(L-lactide-co-e-caprolactone) (PLCL), silk fibroin-(SF), and heparin (Hep), PLCL/SF/Hep bi-layered scaffolds and PLCL/Hep bi-layered scaffolds were prepared by electrospinning. The inner layer was a PLCL/SF/Hep or PLCL/Hep nanofiber membrane, and the outer layer was PLCL/SF nano yarn. The in vitro tests included a hydrophilicity test, mechanical properties test, and blood and cell compatibility evaluation. The in vivo evaluation was conducted via single rabbit carotid artery replacement and subsequent examinations, including ultrasound imaging, immunoglobulin assays, and tissue section staining. Results: Compared to the PLCL/Hep nanofiber membrane, the hydrophilicity of the PLCL/SF/Hep nanofiber membrane was significantly improved. The mechanical strength met application requirements. Both the blood and cell compatibility were optimal. Most importantly, the PLCL/SF/Hep scaffolds maintained lumen patency for 3 months after carotid artery transplantation in live rabbits. At the same time, CD31 and alpha-SMA immunofluorescence staining confirmed bionic endothelial and smooth muscle layers remodeling. Conclusion: Using this hybrid strategy, PLCL and SF were combined to manufacture bilayered small-caliber vascular scaffolds; these PLCL/SF/Hep scaffolds showed satisfactory vascular remodeling. Keywords: silk fibroin, small-caliber, vascular remodeling, hybrid strategy
Traditional treatment therapies for tracheal stenosis often cause severe post‐operative complications. To solve the current difficulties, novel and more suitable long‐term treatments are needed. A ...whole‐segment tissue‐engineered trachea (TET) representing the native goat trachea was 3D printed using a poly(caprolactone) (PCL) scaffold engineered with autologous auricular cartilage cells. The TET underwent mechanical analysis followed by in vivo implantations in order to evaluate the clinical feasibility and potential. The 3D‐printed scaffolds were successfully cellularized, as observed by scanning electron microscopy. Mechanical force compression studies revealed that both PCL scaffolds and TETs have a more robust compressive strength than does the native trachea. In vivo implantation of TETs in the experimental group resulted in significantly higher mean post‐operative survival times, 65.00 ± 24.01 days (n = 5), when compared with the control group, which received autologous trachea grafts, 17.60 ± 3.51 days (n = 5). Although tracheal narrowing was confirmed by bronchoscopy and computed tomography examination in the experimental group, tissue necrosis was only observed in the control group. Furthermore, an encouraging epithelial‐like tissue formation was observed in the TETs after transplantation. This large animal study provides potential preclinical evidence around the employment of an orthotopic transplantation of a whole 3D‐printed TET.
A suitable valve scaffold is necessary to replace the pulmonary artery in congenital heart disease (CHD) treatment, especially for children. For clinical and long-term success, biomechanics, ...biocompatibility, functionality and growth potential should be together taken into consideration to construct a tissue-engineered valve scaffold. In this study, a thermally induced phase separation (TIPS)-based strategy combining a three-dimensional (3D) printing mold was utilized to rapidly fabricate poly(
l
-lactic acid)/poly(
l
-lactide-
co
- -caprolactone) (PLLA/PLCL) valve integrated scaffolds with a bionic structure. The novel valve integrated scaffolds exhibited favorable mechanical properties, in comparison to the porcine physiological pulmonary artery. Moreover, it satisfied functional performance in fluid, as demonstrated by the computational fluid dynamics simulation results. H&E and Masson staining further confirmed its excellent biocompatibility and vascularization
in vivo
, and fiber morphology and collagen production indicated its abundant extracellular matrix (ECM) secretion as well. Hence, the overall results supported that this original strategy was an efficient method to fabricate valve integrated scaffolds with potential value for clinical application of complex CHD.
A tri-leaflet valve integrated tubular scaffold was obtained using a 3D printing mold by TIPS. After testing its valuvalar performance
via
computational fluid dynamics, the biocompatibility of resultant valve scaffold was evaluated
in vivo
.
The effective capture and release of circulating tumor cells (CTCs) is of significant importance in cancer prognose and treatment. Here we report a highly efficient method to capture and release ...human leukemic lymphoblasts (CCRF-CEM) using aptamers modified gold nanowire arrays (AuNWs). The gold nanowires, showing tunable morphologies from relatively random pillar deposit to relatively uniform arrays, were fabricated by electrochemical deposition using anodic aluminum oxide (AAO) as template. Upon simply being modified with aptamers by Au–S chemistry, the AuNWs exhibit higher specificity to target cells. Also compared to flat gold substrate, the AuNWs with nanostructure can capture target cells with much higher capture yield. Moreover, the captured CCRF-CEM cells can be released from AuNWs efficiently with little damage through an electrochemical desorption process. We predict that our strategy has great potential in providing a simple and economical platform for CTCs isolation, cancer diagnosis, and therapy.
Multiprotein bridging factor 1 (MBF1) is an ancient family of transcription coactivators that play a crucial role in the response of plants to abiotic stress. In this study, we analyzed the genomic ...data of five Solanaceae plants and identified a total of 21 MBF1 genes. The expansion of MBF1a and MBF1b subfamilies was attributed to whole-genome duplication (WGD), and the expansion of the MBF1c subfamily occurred through transposed duplication (TRD). Collinearity analysis within Solanaceae species revealed collinearity between members of the MBF1a and MBF1b subfamilies, whereas the MBF1c subfamily showed relative independence. The gene expression of SlER24 was induced by sodium chloride (NaCl), polyethylene glycol (PEG), ABA (abscisic acid), and ethrel treatments, with the highest expression observed under NaCl treatment. The overexpression of SlER24 significantly enhanced the salt tolerance of tomato, and the functional deficiency of SlER24 decreased the tolerance of tomato to salt stress. SlER24 enhanced antioxidant enzyme activity to reduce the accumulation of reactive oxygen species (ROS) and alleviated plasma membrane damage under salt stress. SlER24 upregulated the expression levels of salt stress-related genes to enhance salt tolerance in tomato. In conclusion, this study provides basic information for the study of the MBF1 family of Solanaceae under abiotic stress, as well as a reference for the study of other plants.
A Gγ protein regulates alkaline sensitivity in crops Zhang, Huili; Yu, Feifei; Xie, Peng ...
Science (American Association for the Advancement of Science),
03/2023, Letnik:
379, Številka:
6638
Journal Article
Recenzirano
The use of alkaline salt lands for crop production is hindered by a scarcity of knowledge and breeding efforts for plant alkaline tolerance. Through genome association analysis of sorghum, a ...naturally high-alkaline-tolerant crop, we detected a major locus,
(
), specifically related to alkaline-salinity sensitivity. An
allele with a carboxyl-terminal truncation increased sensitivity, whereas knockout of
increased tolerance to alkalinity in sorghum, millet, rice, and maize.
encodes an atypical G protein γ subunit that affects the phosphorylation of aquaporins to modulate the distribution of hydrogen peroxide (H
O
)
These processes appear to protect plants against oxidative stress by alkali. Designing knockouts of
homologs or selecting its natural nonfunctional alleles could improve crop productivity in sodic lands.
Toll-like receptors (TLRs) have crucial roles in innate immunity, functioning as pattern-recognition receptors. TLR13 recognizes a conserved sequence from bacterial 23S rRNA and then triggers an ...immune response. Here we report the crystal structure of the mouse TLR13 ectodomain bound by a 13-nt single-stranded (ss) RNA derived from 23S rRNA. The ssRNA induces TLR13 dimerization but assumes a stem-loop-like structure that is completely different from that in the bacterial ribosome but nevertheless is crucial for TLR13 recognition. Most of the RNA nucleotides are splayed out to make base-specific contacts with the concave surface of TLR13, and RNA-specific interactions are important to allow TLR13 to distinguish RNA from DNA. Interestingly, a viral-derived 16-nt ssRNA predicted to form a similar stem-loop-like structure also induces TLR13 activation. Together, our results reveal the structural mechanism of TLR13's sequence- and conformation-specific recognition of ssRNA.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SBMB, UILJ, UKNU, UL, UM, UPUK
Higher plants have evolved multiple RNA‐dependent RNA polymerases (RDRs), which work with Dicer‐like (DCL) proteins to produce different classes of small RNAs with specialized molecular functions. ...Here we report that OsRDR6, the rice (Oryza sativa L.) homolog of Arabidopsis RDR6, acts in the biogenesis of various types and sizes of small RNAs. We isolated a rice osrdr6‐1 mutant, which was temperature sensitive and showed spikelet defects. This mutant displays reduced accumulation of tasiR‐ARFs, the conserved trans‐acting siRNAs (tasiRNAs) derived from the TAS3 locus, and ectopic expression of tasiR‐ARF target genes, the Auxin Response Factors (including ARF2 and ARF3/ETTIN). The loss of tasiR‐mediated repression of ARFs in osrdr6‐1 can explain its morphological defects, as expression of two non‐targeted ARF3 gene constructs (ARF3muts) in a wild‐type background mimics the osrdr6 and osdcl4‐1 mutant phenotypes. Small RNA high‐throughput sequencing also reveals that besides tasiRNAs, 21‐nucleotide (nt) phased small RNAs are also largely dependent on OsRDR6. Unexpectedly, we found that osrdr6‐1 has a strong impact on the accumulation of 24‐nt phased small RNAs, but not on unphased ones. Our work uncovers the key roles of OsRDR6 in small RNA biogenesis and directly illustrates the crucial functions of tasiR‐ARFs in rice development.
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