A Study on the Use of Phase Transition Lysozyme-Loaded Minocycline Hydrochloride in the Local Treatment of Chronic Periodontitis.

Periodontitis is the most important oral disease causing human tooth loss. Although supragingival and subgingival scaling is the main strategy of periodontitis clinical treatments, drug treatment has an indispensable auxiliary role to some degree. Periodontitis medical treatment is divided into systemically administered treatments and local periodontally administered treatments. Compared with systemic administration, local administration can increase local drug concentrations, reduce dosages, and prolong action times while also improving patient compliance and avoiding possible adverse effects due to systemic administration responses. However, some studies show that minocycline ointment, a clinical local drug commonly used in periodontal pockets, has an unstable release rate; 80% of the drug is usually released within 2-3 days after pocket placement. This release is not conducive to controlling periodontal infection and may hinder the periodontal tissue repair and regeneration. Therefore, choosing a suitable carrier for minocycline hydrochloride is necessary to control its local release in periodontal tissue. Phase transition lysozyme (PTL) has been widely used in many studies and the development of macromolecular carrier material, and we selected PTL as the carrier for minocycline hydrochloride drugs because of its good biocompatibility, good drug-carrying capacity, and stable release. Due to its release characteristics and simple preparation, PTL is a promising carrier material.

Electrospun porous poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/lecithin scaffold for bone tissue engineering.

Bone tissue engineering has emerged as a promising restorative strategy for bone reconstruction and bone defect repair. It is challenging to establish an appropriate scaffold with an excellent porous microstructure for bone defects and thereby promote bone repair. In this study, electrospinning as a simple and efficient technology was employed to fabricate a porous poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) scaffold coated with lecithin. The morphology, phase composition, and physical properties of the electrospun P34HB/lec scaffold were characterized. Meanwhile, cellular behaviors of bone marrow mesenchymal stem cells (BMSCs), including proliferation, adhesion, migration, osteogenic differentiation, and related gene expression, were also investigated. Finally, a rat subcutaneous implant model and a calvarial defect model were used to evaluated the biocompatibility and effect of these scaffolds on bone repair, respectively. The in vitro results demonstrated that these electrospun fibers were interwoven with each other to form the porous P34HB/lec scaffold and the addition of lecithin improved the hydrophilicity of the pure P34HB scaffold, enhanced the efficiency of cell migration, and decreased inflammatory response. Furthermore, the in vivo results showed that P34HB/lec scaffold had excellent biocompatibility, improved the vascularization, and promoted the bone regeneration. All these results indicated that nanofibers of P34HB scaffolds in combination with the lecithin could exert a synergistic effect on promoting osteogenesis and regeneration of bone defects; thus, the P34HB scaffold with lecithin showed great application potential for bone tissue engineering.

Scientometric Analysis of Dental Implant Research over the Past 10 Years and Future Research Trends.

BACKGROUND: We conducted a bibliometrics analysis to explore the recent trends in dental implant research which could help researchers have a clear grasp of the relevant research hotspots and prospects. Material and Methods. Altogether, 15,770 articles on dental implants, from January 1, 2010, to October 31, 2019, were selected from the Web of Science Core Collection. We used BICOMB software to extract the high-frequency MeSH terms and construct binary and coword matrices. gCLUTO software was used for biclustering and visual analysis, Ucinet 6 software for social network analysis, SCIMAT software for strategic diagram building, Citespace 5.5 software to form timeline visualization, and VOSviewer software, eventually, for bibliometrics cocitation network. RESULTS: Altogether, 72 high-frequency keywords were extracted from the selected articles and 4 clusters and 7 subcategories were identified through biclustering analysis in the dental implant research field. The use of the strategic diagram also enabled us to find the research hotspot and development trends. CONCLUSIONS: The survival rate of dental implants and subsequent restoration have always been the core focus of research. Sinus floor elevation and guided bone regeneration are worthy of constant exploration owing to their reliability. With continuous improvement in technology, immediate loading could become a future research hot spot.

Radial P34HB Electrospun Fiber: A Scaffold for Bone Tissue Engineering.

Finding suitable scaffold material is always an enormous challenge in the study of bone tissue engineering. Designing and preparing bone scaffolds with biomimetic properties is also a difficult problem for bone reparation projects. This project intends to fabricate radial bio-plasticpoly-3-hydroxybutyrate-4-hydroxybutyrate (P34HB) electrospun fibers scaffold that mimic structural, compositional and stiffness properties via an electro spinning technique. The surface morphology, hydrophilicity of the radial fibers scaffold were tested, a contact angle meter and a universal material tester. Bone marrow mesenchymal stem cell (BMSC) morphologies on radial P34HB electrospun fibers scaffold were observed after cell culture under fluorescence microscopy. Tests of cell viability on radial P34HB electrospun fibers scaffold were conducted. We further tested the osteogenic differentiation ability of radial fibers scaffold. These results showed that radial P34HB electrospun fibers scaffold have good biosafety, biocompatibility and osteogenic induction. The radial structure of the scaffold also has a strong effect on the induction of bone formation. Moreover, the structure could also improve the bone contact area of the implant and increase the locking and fixation between the implant and the bone. We plan to apply this procedure to animal experiments for bone defect repair in further research.

P34HB electrospun fibres promote bone regeneration in vivo.

OBJECTIVE: Bone tissue engineering was introduced in 1995 and provides a new way to reconstruct bone and repair bone defects. However, the design and fabrication of suitable bionic bone scaffolds are still challenging, and the ideal scaffolds in bone tissue engineering should have a three-dimensional porous network, good biocompatibility, excellent biodegradability and so on. The purpose of our research was to investigate whether a bioplasticpoly3-hydroxybutyrate4-hydroxybutyrate (P34HB) electrospun fibre scaffold is conducive to the repair of bone defects, and whether it is a potential scaffold for bone tissue engineering. MATERIALS AND METHODS: The P34HB electrospun fibre scaffolds were prepared by electrospinning technology, and the surface morphology, hydrophilicity, mechanical properties and cytological behaviour of the scaffolds were tested. Furthermore, a calvarial defect model was created in rats, and through layer-by-layer paper-stacking technology, the P34HB electrospun fibre scaffolds were implanted into the calvarial defect area and their effect on bone repair was evaluated. RESULTS: The results showed that the P34HB electrospun fibre scaffolds are interwoven with several fibres and have good porosity, physical properties and chemical properties and can promote cell adhesion and proliferation with no cytotoxicity in vitro. In addition, the P34HB electrospun fibre scaffolds can promote the repair of calvarial defects in vivo. CONCLUSIONS: These results demonstrated that the P34HB electrospun fibre scaffold has a three-dimensional porous network with good biocompatibility, excellent biosafety and ability for bone regeneration and repair; thus, the P34HB electrospun fibre scaffold is a potential scaffold for bone tissue engineering.

Adipose-derived stem cells combined with inorganic bovine bone in calvarial bone healing in rats with type 2 diabetes.

BACKGROUND: Clinical studies have revealed that patients with type 2 diabetes mellitus (DM) have higher implant and bone grafting failure rates than the general population, likely owing to inferior bone healing. The authors sought to investigate whether adipose-derived stem cells (ASCs) combined with inorganic bovine bone improves bone repair in calvarial vertical critical-sized defects (CSDs) in rats with type 2 DM. METHODS: Bovine bone alone or seeded with 3 × 10(5), 3 × 10(6), or 3 × 10(7) ASCs/graft was randomly transplanted into calvarial CSDs in rats with DM induced by a high-fat diet with low-dose streptozotocin. Specimens were assayed using microcomputed tomography and histomorphometry at 4 and 8 weeks postimplantation. RESULTS: The histologic results showed an increase in new bone formation in the experimental groups compared with the control group. Both bone volume/total volume and trabecular thickness of newly formed bone within CSDs were the highest, and trabecular spacing was the lowest, in the 3 × 10(6) group at 8 weeks for the most favorable outcome. The results showed that the amount of new bone was greatest in the 3 × 10(6) group by 8 weeks. CONCLUSIONS: ASCs enhanced vertical bone regeneration in calvarial defects in rats with type 2 DM, when used in association with bovine bone scaffolds. The findings suggest that a combination of ASCs and bovine bone scaffolds could improve bone quantity in vertical bone defects.