3D printed high-precision porous scaffolds prepared by fused deposition modeling induce macrophage polarization to promote bone regeneration.

Macrophage-mediated bone immune responses significantly influence the repair of bone defects when utilizing tissue-engineered scaffolds. Notably, the scaffolds' physical structure critically impacts macrophage polarization. The optimal pore size for facilitating bone repair remains a topic of debate due to the imprecision of traditional methods in controlling scaffold pore dimensions and spatial architecture. In this investigation, we utilized fused deposition modeling (FDM) technology to fabricate high-precision porous polycaprolactone (PCL) scaffolds, aiming to elucidate the impact of pore size on macrophage polarization. We assessed the scaffolds' mechanical attributes and biocompatibility. Real-time quantitative reverse transcription polymerase chain reaction was used to detect the expression levels of macrophage-related genes, and enzyme linked immunosorbent assay for cytokine secretion levels.In vitroosteogenic capacity was determined through alkaline phosphatase and alizarin red staining. Our findings indicated that macroporous scaffolds enhanced macrophage adhesion and drove their differentiation towards the M2 phenotype. This led to the increased production of anti-inflammatory factors and a reduction in pro-inflammatory agents, highlighting the scaffolds' immunomodulatory capabilities. Moreover, conditioned media from macrophages cultured on these macroporous scaffolds bolstered the osteogenic differentiation of bone marrow mesenchymal stem cells, exhibiting superior osteogenic differentiation potential. Consequently, FDM-fabricated PCL scaffolds, with precision-controlled pore sizes, present promising prospects as superior materials for bone tissue engineering, leveraging the regulation of macrophage polarization.

Effect of dietary patterns on dental caries among 12-15 years-old adolescents: a cross-sectional survey.

BACKGROUND: Several factors can influence the risk of dental caries, among which dietary factors have a significance impact on the occurrence of dental caries. The limitation of current studies is that they only focus on the influence of individual foods on the risk of dental caries. This study use cluster analysis to examine the relationship between dietary patterns and dental caries experience among adolescents aged 12-15. METHODS: Based on data from the first oral epidemic survey in Shanxi Province, a cross-sectional study was conducted among 11,351 adolescents aged 12-15 in Shanxi Province through oral examination and questionnaires. The questionnaire included the intake frequency of seven types of food. Descriptive statistics, cluster analysis, and multinomial logistic regression were used to analyze the association between dietary patterns and dental caries experience. RESULTS: The prevalence rate of caries was 44.57% and the mean DMFT score was 0.98 ± 1.49 in adolescents aged 12-15 in Shanxi Province. The caries rate was higher in females than males (X2 = 103.59, P < 0.001). Adolescents who grow up in one-child families have a lower caries risk than those who grow up in families with more than one child (OR:0.91; 95%CI:0.84-0.97). The dietary patterns of adolescents aged 12-15 can be divided into eight types, among which refreshments-rich diet (OR:1.47; 95%CI,1.22-1.77) can increase the risk of caries, while the coarse-grains-rich dietery pattern (OR:0.90; 95%CI, 0.79-0.97) has a lower caries risk. CONCLUSIONS: Social determinants of health such as sex, family size and dietary patterns influence the risk of dental caries. Certain dietary patterns could increase or decrease the risk of caries. The government, school canteens and news media should take dietary pattern factors seriously.

Preparation and characterization of a biocompatible glucose-sensitive electrospun nanofibers scaffolds containing dexamethasone with enhanced osteogenic propertiesin vitrohigh glucose environment.

Diabetes has made it challenging to repair alveolar bone defects. A successful method for bone repair utilizes a glucose-sensitive osteogenic drug delivery. This study created a new glucose-sensitive nanofiber scaffold with controlled dexamethasone (DEX) release. DEX-loaded polycaprolactone/chitosan nanofibers scaffolds were created using electrospinning. The nanofibers had high porosity (>90%) and proper drug loading efficiency (85.51 ± 1.21%). Then, glucose oxidase (GOD) was immobilized on the obtained scaffolds by a natural biological cross-linking agent, genipin (GnP), after soaking in the mixture solution containing GOD and GnP. The enzyme properties and glucose sensitivity of the nanofibers were investigated. The results showed that GOD was immobilized on the nanofibers and exhibited good enzyme activity and stability. Meanwhile, the nanofibers expanded gradually in response to the increase in glucose concentration, followed by the release of DEX increased. The phenomena indicated that the nanofibers could sense glucose fluctuation and possess favorable glucose sensitivity. In addition, the GnP nanofibers group showed lower cytotoxicity in the biocompatibility test compared with a traditional chemical cross-linking agent. Lastly, the associated osteogenesis evaluation found that the scaffolds effectively promoted MC3T3-E1 cells' osteogenic differentiation in high-glucose environments. As a result, the glucose-sensitive nanofibers scaffolds offer a viable treatment option for people with diabetes with alveolar bone defects.

Glucose-sensitive delivery of tannic acid by a photo-crosslinked chitosan hydrogel film for antibacterial and anti-inflammatory therapy.

A glucose-sensitive antibacterial and anti-inflammatory hydrogel film with controlled release of tannic acid (TA) was synthesized using chitosan (CS). Specifically, the photo-crosslinked CS hydrogel was first obtained and then immersed in TA solution to generate composite hydrogel film with enhanced mechanical properties. Subsequently, N-hydroxysuccinimide/1-ethyl-3-(3-dimethylaminopropyl) carbodiimide based coupling chemistry was used to covalently crosslink glucose oxidase (GOx) to CS to obtain glucose sensitivity. The physicochemical properties, including chemical composition, enzyme-related characteristics, glucose responsiveness, and mechanical strength, were thoroughly investigated, followed by the cytotoxicity, antibacterial and anti-inflammatory tests. The results showed that the GOx immobilized on the film surface by covalent bonding gave better stability than those that were physically adsorbed. In addition, it could quickly and correspondingly modify its inner pore structure in response to the glucose stimulus and then control the loaded TA release. Meanwhile, the TA addition could enhance the film's mechanical properties. The composite hydrogel film demonstrated adequate biocompatibility and can inhibit NO, IL-6, and TNF-α production in stimulated macrophages, as well as Porphyromonas gingivalis growth, demonstrating effective antibacterial and anti-inflammatory activity.

User-friendly microfluidic manufacturing of hydrogel microspheres with sharp needle.

Hydrogel microspheres are flexible microstructures with many fascinating functions, such as three-dimensional cell culture, injection therapy, drug delivery, organoids and microtissues construction. The traditional methods of manufacturing hydrogel microspheres more or less have some shortcomings, such as atomization/emulsion method with uneven sizes; piezoelectric-/thermal-/electric-assisted inkjet with high cell damage and unknown cell growth effects; microfluidic manufacturing with sophisticated microdevices etc, which lead to poor user experiences. Here, we designed a user-friendly microfluidic device to generate hydrogel microspheres with sharp needles that can be replaced at will. Specifically, a commercial tapered opening sharp needle was inserted into a transparent silicone tube with the tapered opening facing the upper wall of the silicone tube. Then, gelatin methacrylate (GelMA) solution and paraffin oil were pumped into the sharp needle and the silicone tube respectively. GelMA microdroplets were formed under the shear stress of the silicone tube and the oil phase, and after being photo-crosslinkedin situ, GelMA microspheres with uniform and adjustable sizes can be generated. Due to the simplicity of our original device, heterogeneous microspheres such as Janus, core-shell and hollow microspheres can be easily manufactured by simple modification of the device. In addition, we demonstrated the strong flexibility and maneuverability of the microspheres through macroscopic free assembly. Finally, we prepared different cell-laden GelMA microspheres, and the cells showed stretching behavior similar to thatin vivoafter a short period culture, which indicated the high bioactivity of GelMA microspheres. Meanwhile, we cultured the Janus cell-laden GelMA microspheres and the assembly of cell-laden GelMA microspheres, where the cells stretched and interacted, demonstrating the potential of GelMA microspheres for co-culture and fabrication of large-scale tissue constructs. In view of the above results, our user-friendly microfluidic manufacturing method of hydrogel microspheres with sharp needles will provide great convenience to relevant researchers.

Application of chronic disease management model in early childhood caries / 口腔疾病防治

@#Early childhood caries (ECC) is not only harmful to children's oral cavity and even the whole body, the government and relevant health departments pay more and more attention to the prevention and treatment of early childhood caries. However, at present, the primary treatment for ECC is the traditional filling therapy. The chronic disease management model can conduct regular testing of chronic non-communicable diseases and their risk factors, and provide long-term and effective professional management to patients by supervision and advice by doctors, nurses and pharmacists. This model has a good effect on slowing down the development of the disease, improving the quality of life of patients and saving public health resources. As a common chronic non-communicable disease, ECC is very suitable for prevention and treatment through chronic disease management. In recent years, chronic disease management models have also been increasingly used in the management of caries. The current common chronic disease management models include the chronic care model, innovative care for chronic condition, and British chronic disease management system models. And above models have certain applications in the management of ECC. How to establish the caries risk assessment system suitable for the diagnosis and treatment model of our country, and how to screen the children with high risk of caries by step-by-step prevention and control network for personalized prevention needed to be further studied in the future.

Ecological determinants of effect of a free pit and fissure sealant program in Shanxi, China, 2017-2018.

BACKGROUND: The aim of this study is to explore the spatial heterogeneity of the retention of PFS in children aged 7-9 years in Shanxi Province, North China and investigate the risk factors associated with PFS retention. METHODS: In this study, 937 children aged 7-9 years from Shanxi Province, China were randomly selected, all of whom had at least one first permanent tooth sealed with PFS in 2016. The children were surveyed after 12 months (in 2017) and 24 months (in 2018). The Geo-detector model was used to explore the spatial heterogeneity of the retention rate of PFS and analyze the influence and interactions of the ecological factors on PFS. RESULTS: 3299 teeth from 937 children were analyzed. The PFS full retention rates after 12 months (in 2017) and 24 months (in 2018) were 81.6% and 75.1%, respectively. The incidence of caries of the first molar was 2.1% after 12 months and 5.4% after 24 months. The spatial heterogeneity of the PFS retention rate after 24 months was significant, which was shown as the retention rate of PFS increased from north to south after 24 months. Remarkably, the natural environmental factors exerted greater influence than the socioeconomic and medical resources factors after 12 months, where the interaction of fluorine in water (FW) had the strongest explanatory power of 52% (P < 0.05). The medical resources were important ecological factors after 24 months, and the percentage of medical technicians (PMT) had the strongest explanatory power of 70% (P < 0.05). CONCLUSION: The natural environmental factors and medical resources factors are important ecological factors determining the spatial pattern. The government should strengthen medical and technician construction in North China, comprehensively control fluoride in water, optimize the allocation of medical resources, and promote the balanced development of regional medicine.

PEI-modified diatomite/chitosan composites as bone tissue engineering scaffold for sustained release of BMP-2.

The bone healing defects resulting from bone disease remain a significant clinical challenge. The bone tissue engineering scaffolds combined with osteoinductive compounds represent an effective approach to overcome this challenge. In this study, a novel chitosan-based scaffold was prepared by incorporating modified natural diatomite (DE) as filler and adsorption element. Specifically, modified-diatomite (MDE) was synthesized by grafting polyethyleneimine (PEI) on the surface of diatomite via hydroxyl groups. The physicochemical characteristics of MDE, including chemical composition, zeta potential, and adsorption behavior, were investigated successively. Further, the mechanical strength, drug release, cytotoxicity and osteogenic activity analyses were carried out for the scaffold material. The FTIR and zeta potential analyses exhibited that the amino groups (-NH2) were grafted on MDE, and the surface potential of diatomite altered from -24 mV to 55 mV. Subsequently, the protein adsorption capacity and cytocompatibility of MDE were observed to be improved as compared to DE. The compressive strength was observed to be enhanced due to the addition of MDE. Besides, the composite scaffold loaded with rhBMP-2 demonstrated a more positive impact on proliferation and osteogenic differentiation of the bone mesenchymal stem cells, thus, indicating an optimal bone regeneration capacity. The findings obtained in this study reveal that the MDE-rhBMP-2/CS composite scaffold can be potentially used to promote the bone tissue regeneration.