A main challenge for use of scaffolds in bone engineering involves non-invasive monitoring in vivo and enhanced bone regeneration. The tissue repair effect of superparamagnetic iron oxide nanoparticles (SPIONs) was demonstrated previously by our group. However, testing in vivo is needed to confirm in vitro results. Here, SPIONs loaded gelatin sponge (GS) was used as a scaffold (SPIONs-GS) and implanted in the incisor sockets of Sprague-Dawley rats. Incisor sockets filled with nothing and filled with GS served as controls. Rats were sacrificed at 2 and 4 weeks. A significant decrease in the signal intensity of T2-weighted magnetic resonance imaging (MRI) in the SPIONs-GS group was noted. Changes in image intensity of scaffolds (indicating scaffold degradation and interaction with host tissues) could be visually monitored over time. Microcomputed tomography showed that the SPIONs-GS group had more newly formed bone (64.44 ± 10.92 vs. 28.1 ± 4.49, p < .0001) and a better preserved alveolar ridge than blank control group at 4 weeks (0.962 ± 0.01 vs. 0.92 ± 0.01, p < .0001). Histology confirmed imaging results, showing good consistency in new bone formation and scaffold degradation. The number of SPIONs decreased rapidly with time due to quick degradation of GS, whereas the number of endocytic SPIONs in cells increased with time. These residual SPIONs, together with newly formed bone, could be detected by MRI at 4 weeks. Therefore, it was clear that SPIONs induced active osteogenesis. In conclusion, good visibility on MRI and enhanced regeneration of bone can be obtained by implanting SPIONs-GS in vivo without using an external magnetic field.

IntroductionScaffold structure plays a vital role in cell behaviors. Compared with two-dimensional structure, 3D scaffolds can mimic natural extracellular matrix (ECM) and promote cell–cell and cell–matrix interactions. The combination of osteoconductive scaffolds and osteoinductive growth factors is considered to have synergistic effects on bone regeneration.Materials and methodsIn this study, core–shell poly(lactide-co-glycolide) (PLGA)/polycaprolactone (PCL)–BMP-2 (PP–B) fibrous scaffolds were prepared through coaxial electrospinning. Next, we fabricated 3D scaffolds based on PP–B fibers with thermally induced self-agglomeration (TISA) method and compared with conventional PLGA/PCL scaffolds in terms of scaffold morphology and BMP-2 release behaviors. Then, rat adipose-derived stem cells (rADSCs) were seeded on the scaffolds, and the effects on cell proliferation, cell morphology, and osteogenic differentiation of rADSCs were detected.ResultsThe results demonstrated that 3D scaffold incorporated with BMP-2 significantly increased proliferation and osteogenic differentiation of rADSCs, followed by PP–B group.ConclusionOur findings indicate that scaffolds with 3D structure and osteoinductive growth factors have great potential in bone tissue engineering.

Vaccination with ultraviolet-attenuated cercariae of Schistosoma japonicum induced protective immunity against challenge infection in experimental animal models. Our preliminary study on the transcription levels of IFN-gamma and IL-4 in splenic CD4+ T cells revealed that attenuated cercariae elicited predominantly a Th1 response in mice at the early stage, whereas normal cercariae stimulated primarily Th2-dependent responses. Further analysis on the gene profile of the skin-draining lymph nodes demonstrated that the levels of IFN-gamma were significantly higher in vaccinated mice than those in infected mice at day 4, 7 and 14 post-vaccination or post-infection. However, for IL-12 and IL-4, the potent inducers of Th1 and Th2 responses, respectively, as well as IL-10, there were no differences over the course of the experiment between the infected and vaccinated mice. To explore the underlying factors that may potentially contribute to elevated IFN-gamma in vaccinated mice, the mRNA profiles of the skin-draining lymph nodes at day 4 post-exposure were compared using oligonucleotide microarrays. Within the 847 probe sets with increased signal values, we focused on chemokines, cytokines and relevant receptors, which were validated by semi-quantitative RT-PCR. A comprehensive understanding of the immune mechanisms of attenuated cercariae-induced protection may contribute to developing efficient vaccination strategies against S. japonicum, especially during the early stage of infection.

Core–shell electrospun scaffolds with γ-Fe2O3 encapsulation were first fabricated with enhanced physical and mechanical properties, and could promote osteogenic differentiation of rADSCs and in vivo bone regeneration.

Although nosocomial infection incidence is relatively low in this eye hospital, our data suggest that different subgroups of patients are prone to certain types of infection. Specific preventive strategies targeting different subgroups of inpatients may further reduce the infection incidence.

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Owing to the ongoing coronavirus disease 2019 (COVID-19) pandemic, we need to pay a particular focus on the impact of coronavirus infection on breast cancer patients. Approximately 70% of breast cancer patients express estrogen receptor (ER), and intervention therapy for ER has been the primary treatment strategy to prevent the development and metastasis of breast cancer. Recent studies have suggested that selective estrogen receptor modulators (SERMs) are a potential therapeutic strategy for COVID-19. With its anti-ER and anti-viral combined functions, SERMs may be an effective treatment for COVID-19 in patients with breast cancer. In this review, we explore the latent effect of SERMs, especially tamoxifen, and the mechanism between ER and virus susceptibility.

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