Silk biomaterials with tunable mechanical properties and biological properties are of special importance for tissue engineering. Here, we fabricated silk fibroin (SF, from Bombyx mori silk) scaffolds from cryogelation under controlled temperature and catalytic cross-linking conditions. Structurally, the cryogelled scaffolds demonstrated a greater β-sheet content but significantly smaller β-sheet domains compared to that without chemical cross-linking and catalyst. Mechanically, the cryogelled scaffolds were softer and highly elastic under tension and compression. The 120% tensile elongation and >85% recoverable compressive strain were among the best properties reported for SF scaffolds. Cyclic compression tests proved the robustness of such scaffolds to resist fatigue. The mechanical properties, as well as the degradation rate of the scaffolds, can be fine-tuned by varying the concentrations of the catalyst and the cross-linker. For biological responses, in vitro rat bone mesenchymal stem cell (rBMSC) culture studies demonstrated that cryogelled SF scaffolds supported better cell attachment and proliferation than the routine freeze-thawed scaffolds. The in vivo subcutaneous implantation results showed excellent histocompatibility and tissue ingrowth for the cryogelled SF scaffolds. This straightforward approach of enhanced elasticity of SF scaffolds and fine-tunability in mechanical performances, suggests a promising strategy to develop novel SF biomaterials for soft tissue engineering and regenerative medicine.

Background Transitioning from theoretical medicine to clinical practice is both an important and difficult process in dental education. Thus, there is an urgent need for teaching methods that can improve the ability of dental students to integrate dental theory with clinical practice. Methods First, we conducted training for problem-based learning based on real clinical cases for dental students. The students were then assigned to dentist/patient roles to rehearse and perform simulated clinical scenarios. Finally, questionnaires, clinical patient care scores, and performance assessments were utilized to evaluate and compare the effectiveness of this training with that of traditional teaching methods. Results Students’ abilities to treat and communicate with patients markedly improved after using this reformed teaching method. Among the 30 enrolled students, 29 liked the method, found it time-efficient, and believed that it could help enhance their problem-solving confidence and interest in prosthodontics. They also believed that this teaching method could help them gain a good understanding of related theoretical material, generally thought that the reformed teaching method was more valuable than the traditional approach, and would like to introduce it to others. Conclusion After the reformed teaching method was implemented, the students not only achieved better scholastically, but also demonstrated greater accuracy in diagnosing the conditions of patients and formulating treatment plans. They were also more frequently acknowledged by patients, indicating that this method is effective for dental students.

The SF layer-by-layer surface functionalized SIS membrane exhibits tunable mechanical properties and degradation rate, satisfactory biocompatibility and good bioactivity.

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Objectives This study aims to evaluate the changes of development trends and research hotspots of biomaterials research from 2013 to 2017, which can identify the general information of papers and explore the changes of research content, thus providing perspectives for the development of biomaterials in China and other countries. Methods Data of the paper were retrieved from the Web of Science Core Collection, and then analyzed by the bibliometric and CiteSpace visualization analysis. Results It was found that a total of 3,839 related papers had been published from the year 2013 to 2017. The analysis of the articles showed that the annual quantity and quality of the articles in the biomaterials research have been increasing since 2013, and the Wang L / Chinese Academy of Sciences were the most productive author/institution. Meanwhile, the keywords “in vitro”, “scaffold”, “nanoparticle” , “mechanical property”, and “biocompatibility” have the relatively higher frequency, and the keywords “apatite”, “deposition”, and “surface modification” have the strongest burst citation. Conclusions After statistics and analysis, we found that biomaterials is a promising research field. The study may be helpful in understanding research trends in this field.

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Background. Human umbilical cord mesenchymal stem cells- (HuMSCs-) based therapy has shown promising results in the treatment of intrauterine adhesions (IUA). In this study, we aimed to construct a HuMSCs-seeded silk fibroin small-intestinal submucosa (SF-SIS) scaffold and evaluate its ability to repair the damaged endometrium in an IUA mouse model. Methods. To identify the functional effect of HuMSCs-SF-SIS scaffolds on the repair of damaged endometrium, a mouse IUA model was established. Uterine morphology and fibrosis were evaluated by hematoxylin-eosin staining and Masson staining. CircRNA sequencing, real-time PCR, and RNA fluorescence in situ hybridization were used to screen and verify the potential circRNAs involved in the repair of damaged endometrium by HuMSCs. Real-time integrated cellular measurement of oxygen consumption rate was performed using the Seahorse XF24 Extracellular Flux Analyzer. The potential downstream miRNAs and proteins of circRNAs were analyzed by dual-luciferase reporter assay and western blot. Results. HuMSCs-SF-SIS not only increased the number of glands but also reduced the ulcer area in the IUA model. circPTP4A2 was elevated in the HuMSCs seeded on the SF-SIS scaffolds and was targeted by miR-330-5p-PDK2. It also stabilized the mitochondrial metabolism of HuMSCs. Moreover, miR-330-5p was found to inhibit PDK2 expression through the 3 ′ UTR target region. A rescue experiment further showed that circPTP4A2-miR-330-5p-PDK2 signaling was critical to HuMSCs-SF-SIS in decreasing the fibrosis area and increasing the number of glands in the IUA model. Conclusion. We demonstrated that circPTP4A2 was elevated in HuMSCs-seeded on SF-SIS scaffolds and stabilized the mitochondrial metabolism through miR-330-5p-PDK2 signaling, which contributes to endometrial repair progression. These findings demonstrate that HuMSCs-seeded SF-SIS scaffolds have potential for the treatment of IUA.