Multiple physical
cues such as hierarchical microstructures, topography,
and stiffness influence cell fate during tissue regeneration. Yet,
introducing multiple physical cues to the same biomaterial remains
a challenge. Here, a synergistic cross-linking strategy was developed
to fabricate protein hydrogels with multiple physical cues based on
combinations of two types of silk nanofibers. β-sheet-rich silk
nanofibers (BSNFs) were blended with amorphous silk nanofibers (ASNFs)
to form composite nanofiber systems. The composites were transformed
into tough hydrogels through horseradish peroxidase (HRP) cross-linking
in an electric field, where ASNFs were cross-linked with HRP, while
BSNFs were aligned by the electrical field. Anisotropic morphologies
and higher stiffness of 120 kPa were achieved. These anisotropic hydrogels
induced osteogenic differentiation and the aligned aggregation of
stem cells in vitro while also exhibiting osteoinductive capacity
in vivo. Improved tissue outcomes with the hydrogels suggest promising
applications in bone tissue engineering, as the processing strategy
described here provides options to form hydrogels with multiple physical
cues.
Gradient biomaterials are considered as preferable matrices for tissue engineering due to better simulation of native tissues. The introduction of gradient cues usually needs special equipment and complex process but is only effective to limited biomaterials. Incorporation of multiple gradients in the hydrogels remains challenges. Here, betasheet rich silk nanofibers (BSNF) were used as building blocks to introduce multiple gradients into different hydrogel systems through the joint action of crosslinking and electric field. The blocks migrated to the anode along the electric field and gradually stagnated due to the solution-hydrogel transition of the systems, finally achieving gradient distribution of the blocks in the formed hydrogels. The gradient distribution of the blocks could be tuned easily through changing different factors such as solution viscosity, which resulted in highly tunable gradient of mechanical cues. The blocks were also aligned under the electric field, endowing orientation gradient simultaneously. Different cargos could be loaded on the blocks and form gradient cues through the same crosslinking-electric field strategy. The building blocks could be introduced to various hydrogels such as Gelatin and NIPAM, indicating the universality. Complex niches with multiple gradient cues could be achieved through the strategy. Silk-based hydrogels with suitable mechanical gradients were fabricated to control the osteogenesis and chondrogenesis. Chondrogenic-osteogenic gradient transition was obtained, which stimulated the ectopic osteochondral tissue regeneration in vivo. The versatility and highly controllability of the strategy as well as multifunction of the building blocks reveal the applicability in complex tissue engineering and various interfacial tissues.
Prostataplex may have short-term effects in improving symptoms and objective measures in Chinese men with lower urinary tract symptoms associated with benign prostatic hyperplasia.
Dexamethasone decreases pain scores within 48 h postoperatively and is associated with significantly reduced narcotic consumption. Dexamethasone as an analgesic therapy appears to be a safe in patients undergoing TKA.
Background: Bone marrow mesenchymal stem cells (BMMSCs) can be used for bone regeneration in the specified condition. Osteogenic differentiation of BMMSCs is controlled by microRNAs (miRNAs) and other factors. This study was aimed to identify the role and mechanism of miR-889 in regulating the osteogenic differentiation of BMMSCs. Methods: Osteoporosis patients and normal control bone tissues were collected and used PCR techniques to identify the change of miR-889 and WNT7A. Moreover, the dynamic change of miR-889 and WNT7A during osteogenic differentiation of BMMSCs was also measured. Bioinformatic analysis was performed to identify the target genes and potential pathways of miR-889. Then, we constructed miR-889 mimic and inhibitor, ALP staining, ARS, osteoblastic-related protein, and Wnt β-catenin signaling pathway-related protein were also measured. WNT7A siRNA was also used to verify the function of miR-889. Results: In the present study, we showed that miR-889 expression was upregulated in osteoporosis patients than healthy control. However, the miR-889 expression was downregulated during osteogenic differentiation. Bioinformatics analysis found that miR-889 targets 666 genes and mainly through Wnt β-catenin signaling pathway. Administrated miR-889 mimic, the ALP activity, and calcium deposition were decreased than the control group, while miR-889 inhibitor shown the opposite trend. And miR-889 could bind the 3′UTR of WNT7A. We further used WNT7A siRNA to explore the function of miR-889, and the results revealed that co-cultured with miR-889 inhibitor and WNT7A siRNA was associated with a reduction of ALP activity and calcium deposition and osteoblastic-related proteins than miR-889 inhibitor alone. Conclusion: Our results revealed that miR-889 plays a negative role in inducing osteogenic differentiation of BMSCs through Wnt β-catenin signaling pathway.
Metal ions provide multifunctional signals for cell and tissue functions, including regeneration. Inspired by metal−organic frameworks (MOFs), nanosized silk protein aggregates with a high negative charge density are used to form stable silk−magnesium ion complexes. Magnesium ions (Mg ions) are added directly to silk nanoparticle solutions, inducing gelation through the formation of silk‐Mg coordination complexes. The Mg ions are released slowly from the nanoparticles through diffusion, with sustained release via tuning the degradation or dissolution of the nanosized silk aggregates. Studies in vitro reveal a dose‐dependent influence of Mg ions on angiogenic and anti‐inflammatory functions. Silk‐Mg ion complexes in the form of hydrogels also stimulate tissue regeneration with a reduced formation of scar tissue in vivo, suggesting potential utility in tissue regeneration.
The results of this clinical observation further elaborated the efficacy and safety of SR oxycodone tablets in the treatment of moderate to severe painful diabetic peripheral neuropathy in China.
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