It is an effective way in bone tissue engineering to promote the mechanical and osteogenic capability of hydrogels by encapsulating mineral particles into polymer matrix. In this work, we reported novel kinds of nanocomposite scaffolds based on hydroxypropyl chitosan/ aldehyde dextran hydrogel (CDH) and strontium-nanohydroxyapatite (Sr-nHA) nanoparticles. The molar ratios of Sr/(Sr + Ca) at 0% (nHA), 50% (Sr50nHA), and 100% (Sr100nHA) were fabricated and subsequently incorporated into CDH. The characterization of Sr-nHA/CDH constructs and CDH alone was studied by Fourier transform infrared analysis, X-ray powder diffraction detection, and scanning electron microscopy. The physical properties of hydrogels were further detected by swelling studies, degradation behavior, rheological measurements, mechanical testing, and ion-release behavior. Cell biocompatibility on the scaffolds was determined in vitro, and bone formation in vivo was examined by a rat calvarium defect model. The results showed that either nHA or Sr-nHA nanoparticles incorporation into CDH would significantly improve the rheological and mechanical properties (P < 0.05). The Sr 2+ released from the Sr100nHA/CDH was in the range of optimal concentration for proosteogenesis. The addition of Sr-nHA significantly enhanced the cell proliferation and osteogenic differentiation of osteoblasts (P < 0.05). The Sr100nHA/CDH exerted the highest promotion on the polarization of macrophages toward the M2 phenotype. The new bone formation of Sr100nHA/CDH was 2.5-fold and 2-fold higher than that of CDH at 4 and 8 weeks, respectively (P < 0.05). HE staining, Masson's trichrome staining, and immunofluorescence staining of OCN results also confirmed that Sr100nHA/CDH had superior bone regeneration compared to other hydrogels in vivo. In conclusion, this novel in situ gelling hydrogel based on injectable and load-bearing 100% Sr-substituted nHA in CDH is expected to have wide orthopedic, dental, and craniofacial applications to enhance bone regeneration.

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Background Due to the rapid spread of coronavirus disease 2019 (COVID-19) around the world, the World Health Organization (WHO) declared it a global pandemic on March 11, 2020. This declaration had an unprecedented impact on health profession education, especially the clinical clerkship of nursing and medical students. The teaching hospitals had to suspend traditional bedside clinical teaching and switch to digital education. Objective To systematically synthesize the available literature on the application of digital education in undergraduate nursing and medical interns during the COVID-19 pandemic. Design A systematic review informed by PRISMA guidelines. Data sources Five electronic databases were systematically searched: PubMed, Embase, MEDLINE (OVID), CINAHL and the Cochrane Library. Review methods The retrieved articles were screened at the title, abstract, and full text stages. The Mixed-Methods Appraisal Tool (MMAT) was used to assess the quality of quantitative and mixed-method studies. Then, two reviewers extracted the quantitative data of the included studies. Results A total of 4596 studies were identified following a comprehensive search, and 16 studies were included after removing duplicates and screening, which focused on undergraduate nursing students (3 studies) and medical students (13 studies). We found that the standalone digital education modalities were as effective as conventional learning for knowledge and practice. Different educational technologies have different effects on the knowledge and practice of interns. Conclusion Digital education plays a significant role in distance training for nursing and medical interns both now and in the future. The overall risk of bias was high, and the quality of evidence was found to be variable. There is a need for further research designing more quasi-experimental studies to assess the effectiveness of standalone digital education interventions for the remote training of nursing or medical interns to be fully prepared for emergencies.

Guided tissue regeneration (GTR) is a promising treatment for periodontal tissue defects, which generally uses a membrane to build a mechanical barrier from the gingival epithelium and hold space for the periodontal regeneration especially the tooth-supporting bone. However, existing membranes possess insufficient mechanical properties and limited bioactivity for periodontal bone regenerate. Herein, fish collagen and polyvinyl alcohol (Col/PVA) dual-layer membrane were developed via a combined freezing/thawing and layer coating method. This dual-layer membrane had a clear but contact boundary line between collagen and PVA layers, which were both hydrophilic. The dual membrane had an elongation at break of 193 ± 27% and would undergo an in vitro degradation duration of more than 17 days. Further cell experiments showed that compared with the PVA layer, the collagen layer not only presented good cytocompatibility with rat bone marrow-derived mesenchymal stem cells (BMSCs), but also promoted the osteogenic genes (RUNX2, ALP, OCN, and COL1) and protein (ALP) expression of BMSCs. Hence, the currently developed dual-layer membranes could be used as a stable barrier with a stable degradation rate and selectively favor the bone tissue to repopulate the periodontal defect. The membranes could meet the challenges encountered by GTR for superior defect repair, demonstrating great potential in clinical applications.

A hydrogel with improved interfacial compatibility was formed to promote osteogenesis by establishing electrostatic bonds.

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Titanium (Ti) alloys are widely used in tissue engineering, but their applications are limited by low strength, bactericidal properties, and metal ion release. Beta Ti alloys are promising materials for load‐bearing orthopedic implants due to their excellent corrosion resistance and high biocompatibility. Herein, developed new beta‐Ti alloys including Ti–Nb–Zr–Sn (Ti–Sn) and Ti–Nb–Zr–Ta–Si (Ti–Si) to improve structural and biochemical features of the existing Ti alloys as orthopedic implants. The new Ti–Sn and Ti–Si alloys were fabricated using mechanical ball milling and spark plasma sintering techniques respectively and compared with commercially pure Ti alloys on hydrophilicity, surface characteristics and cytotoxicity, proliferative and osteogenic differentiation effects as well as biocompatibility in human bone osteosarcoma cell line (MG63). The new beta Ti alloys showed no significant differences in proliferation and cytotoxicity on the MG63 cells. Both Ti–Sn and Ti–Si alloys, compared to the commercial pure Ti, improved the biological profile and upregulated the expressions of runt‐related transcription factor 2, osterix, and collagen mRNA levels in the MG63 cells. The Ti–Si alloy showed greater cell proliferation and osteoblastic protein expression and a better biological profile compared to the Ti and Ti–Sn alloys. The novel beta Ti alloys exhibited promising potentials in orthopedic applications.

Titanium alloys are widely accepted as orthopedic or dental implant materials in the medical field. It is important to evaluate the biocompatibility of an implant material prior to use. A new β‐type ultrafine‐grained Ti–28Nb–2Zr–8Sn (TNZS) alloy with low Young's modulus of 31.6 GPa was fabricated. This study aims to evaluate the biocompatibility of TNZS alloy. In this study, we examined the microstructure, chemical composition and surface wettability of the TNZS alloy. The mouse embryonic osteoblast MC3T3‐E1 cells and human umbilical vein endothelial cells (HUVECs) were cultured to study the cytocompatibility of TNZS alloy. Also, we evaluated the proinflammatory response of TNZS alloy in vitro and in vivo. The results show that the TNZS did not cause cytotoxicity, genotoxicity to MC3T3‐E1 cells and HUVECs. Whereas, the TNZS alloy could significantly promote the cell proliferation, cell spreading and cell adhesion of MC3T3‐E1 cells and HUVECs, as well as facilitate the osteogenic differentiation of MC3T3‐E1 cells. Moreover, the TNZS alloy did not induce any remarkable proinflammatory response in vitro and in vivo. Thus, the novel TNZS alloy with an elasticity closer to that of human bone is biologically safe and could be a potential candidate for biomedical implant application. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1628–1639, 2019.