Traditional surgical intervention and antibiotic treatment are poor and even invalid for chronic diseases including periodontitis induced by diverse oral pathogens, which often causes progressive destruction of tissues, even tooth loss, and systemic diseases. Herein, an ointment comprising atomic-layer Fe2O3-modified two-dimensional porphyrinic metal-organic framework (2D MOF) nanosheets is designed by incorporating a polyethylene glycol matrix. After the atomic layer deposition surface engineering, the enhanced photocatalytic activity of the 2D MOF heterointerface results from lower adsorption energy and more charge transfer amounts due to the synergistic effect of metal-linker bridging units, abundant active sites, and an excellent light-harvesting network. This biocompatible and biodegradable 2D MOF-based heterostructure exhibits broad-spectrum antimicrobial activity (99.87 ± 0.09%, 99.57 ± 0.21%, and 99.03 ± 0.24%) against diverse oral pathogens (Porphyromonas gingivalis, Fusobacterium nucleatum, and Staphylococcus aureus) by the synergistic effect of reactive oxygen species and released ions. This photodynamic ion therapy exhibits a superior therapeutic effect to the reported clinical periodontitis treatment owing to rapid antibacterial activity, alleviative inflammation, and improved angiogenesis.

2D MOF Periodontitis Photodynamic Ion Therapy.

The role of additive manufacturing for biomedical applications: A critical review

Bone defect and osteoporosis are common in clinic which are seriously harmful for public health. Bionic bone tissue engineering scaffolds are very important for bone tissue repair and reconstruction. In this study, different bionic bone tissue engineering scaffolds were constructed by computer-aided design and fabricated by selected laser melting. Novel porous structures were designed by using parameterization modeling. The accurate models with key characteristics such as porosity and the mechanical property of scaffolds were studied. Compared with the designed model, the error of the selective laser melting (SLM) printed scaffold porosity was less than 2.73%. The mechanical properties of the prepared scaffold can be calculated by finite element analysis of 3D models, and the mechanical properties of the 3D printed samples were consistent with the model design. Through the design, manufacture, characterization and evaluation of the scaffold porous structures, the parametric modeling of porous titanium bone tissue engineering scaffold with good mechanical and biological properties was realized. Optimized design and precisely manufactured implants are very important for bone tissue repair and reconstruction.

Bionic design and 3D printing of porous titanium alloy scaffolds for bone tissue repair

Ca2+-supplying black phosphorus-based scaffolds fabricated with microfluidic technology for osteogenesis.

Summary Smart contact lenses attract extensive interests due to their capability of directly monitoring physiological and ambient information. However, previous demonstrations usually lacked efficient sensor modalities, facile fabrication process, mechanical stability, or biocompatibility. Here, we demonstrate a flexible approach for fabrication of multifunctional smart contact lenses with an ultrathin MoS2 transistors-based serpentine mesh sensor system. The integrated sensor systems contain a photodetector for receiving optical information, a glucose sensor for monitoring glucose level directly from tear fluid, and a temperature sensor for diagnosing potential corneal disease. Unlike traditional sensors and circuit chips sandwiched in the lens substrate, this serpentine mesh sensor system can be directly mounted onto the lenses and maintain direct contact with tears, delivering high detection sensitivity, while being mechanically robust and not interfering with either blinking or vision. Furthermore, the in vitro cytotoxicity tests reveal good biocompatibility, thus holding promise as next-generation soft electronics for healthcare and medical applications.

Integrated contact lens sensor system based on multifunctional ultrathin MoS2 transistors.

Peri-implant infection is one of the biggest threats to the success of dental implant. Existing coatings on titanium surfaces exhibit rapid decrease in antibacterial efficacy, which is difficult to promisingly prevent peri-implant infection. Herein, we report an N-halamine polymeric coating on titanium surface that simultaneously has long-lasting renewable antibacterial efficacy with good stability and biocompatibility. Our coating is powerfully biocidal against both main pathogenic bacteria of peri-implant infection and complex bacteria from peri-implantitis patients. More importantly, its antibacterial efficacy can persist for a long term (e.g., 12~16 weeks) in vitro, in animal model, and even in human oral cavity, which generally covers the whole formation process of osseointegrated interface. Furthermore, after consumption, it can regain its antibacterial ability by facile rechlorination, highlighting a valuable concept of renewable antibacterial coating in dental implant. These findings indicate an appealing application prospect for prevention and treatment of peri-implant infection.

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Long-lasting renewable antibacterial porous polymeric coatings enable titanium biomaterials to prevent and treat peri-implant infection

In recent years, various composite scaffolds based on hydroxyapatite have been developed for bone tissue engineering. However, the poor cell survival micro-environment is still the major problem limiting their practical applications in bone repairing and regeneration. In this study, we fabricated a class of fluffy and porous three-dimensional composite fibrous scaffolds consisting of hydroxyapatite and polyacrylonitrile by employing an improved electrospinning technique combined with a bio-mineralization process. The fluffy structure of the hydroxyapatite/polyacrylonitrile composite scaffold ensured the cells would enter the interior of the scaffold and achieve a three-dimensional cell culture. Bone marrow mesenchymal stem cells were seeded into the scaffolds and cultured for 21 days in vitro to evaluate the response of cellular morphology and biochemical activities. The results indicated that the bone marrow mesenchymal stem cells showed higher degrees of growth, osteogenic differentiation and mineralization than those cultured on the two-dimensional hydroxyapatite/polyacrylonitrile composite membranes. The obtained results strongly supported the fact that the novel three-dimensional fluffy hydroxyapatite/polyacrylonitrile composite scaffold had potential application in the field of bone tissue engineering.

/pdf/a-three-dimensional-hydroxyapatite-polyacrylonitrile-3c5jcca02e.pdf

A three-dimensional hydroxyapatite/polyacrylonitrile composite scaffold designed for bone tissue engineering

Molybdenum disulphide (MoS2) exhibits unique properties that are useful for various biomedical applications. Owing to its distinct characteristics and osteogenic differentiation promotion effect, this material has been studied extensively. However, the effect of cell density on osteogenic differentiation between MoS2-based biomaterials and cells is still unknown. In this study, we used MoS2/polyacrylonitrile (PAN) composite nanofibres as substrates to evaluate the effect of cellular density on the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). We created different experimental groups with increasing cell seeding densities and investigated cellular behaviours, biocompatibility, proliferation and osteogenic properties. The results show that MoS2/PAN composite nanofibres can positively regulate osteogenic differentiation. More importantly, in the presence of standard culture conditions, 1.0 × 104 cells/cm2 is the most efficient and suitable cell seeding density for BMSCs osteogenic differentiation. Our findings suggest that the optimal cell density for osteogenesis is vital for the osteogenic differentiation of BMSCs when these cells are cultured onto MoS2-based biomaterials.

Osteogenic differentiation of BMSCs on MoS 2 composite nanofibers with different cell seeding densities

To compare stress distribution and failure probability in maxillary premolars restored by simple occlusal veneer (SOV) and buccal-occlusal veneer (BOV) with 3 different CAD/CAM materials. A maxillary premolar was digitized by a micro-CT scanner. Three-dimensional dynamic scan data were transformed, and finite element models of 2 different models (SOV and BOV restored teeth) were designed. Three different CAD/CAM materials, including lithium disilicate glass ceramic (LD) IPS e.max CAD, polymer-infiltrated ceramic-network (PICN) Vita Enamic, and resin nano-ceramic (RNC) Lava Ultimate, were designated to both veneers. Maximum principle stresses were determined by applying a 300-N axial load to the occlusal surface. Weibull analyses were performed to calculate the failure probability of the models. LD-restored teeth showed the highest stress in the veneer, lowest stress in substrate teeth, and lowest failure probability for the overall system; RNC-restored teeth showed the lowest stress in the veneer, highest stress in substrate teeth, and highest failure probability. No significant differences were found in the cement layer among the different models. No significant differences of stress and failure probability existed between SOV and BOV preparations. CAD/CAM composite resin occlusal veneers bear lower maximum stress than ceramic veneers. Teeth restored by composite veneers are more prone to failure than those restored by ceramic veneers. Additional reduction of the buccal surface did not increase the stress on the occlusal veneer under axial load. Both occlusal veneers could be used under physiological masticatory force. CAD/CAM glass ceramic was safer than composite resins.

Estimation of stress distribution and risk of failure for maxillary premolar restored by occlusal veneer with different CAD/CAM materials and preparation designs.

Leiyan Zou

Papers

Long-lasting renewable antibacterial porous polymeric coatings enable titanium biomaterials to prevent and treat peri-implant infection

A three-dimensional hydroxyapatite/polyacrylonitrile composite scaffold designed for bone tissue engineering

Osteogenic differentiation of BMSCs on MoS 2 composite nanofibers with different cell seeding densities

Estimation of stress distribution and risk of failure for maxillary premolar restored by occlusal veneer with different CAD/CAM materials and preparation designs.

Effect of preparation design on the fracture behavior of ceramic occlusal veneers in maxillary premolars.