Co-culture of STRO1 + human gingival mesenchymal stem cells and human umbilical vein endothelial cells in 3D spheroids: enhanced in vitro osteogenic and angiogenic capacities.

Stem cell spheroid is a promising graft substitute for bone tissue engineering. Spheroids obtained by 3D culture of STRO1+ Gingival Mesenchymal Stem Cells (sGMSCs) (sGMSC spheroids, GS) seldom express angiogenic factors, limiting their angiogenic differentiation in vivo. This study introduced a novel stem cell spheroid with osteogenic and angiogenic potential through 3D co-culture of sGMSCs and Human Umbilical Vein Endothelial Cells (HUVECs) (sGMSC/HUVEC spheroids, GHS). GHS with varying seeding ratios of sGMSCs to HUVECs (GHR) were developed. Cell fusion within the GHS system was observed via immunofluorescence. Calcein-AM/PI staining and chemiluminescence assay indicated cellular viability within the GHS. Furthermore, osteogenic and angiogenic markers, including ALP, OCN, RUNX2, CD31, and VEGFA, were quantified and compared with the control group comprising solely of sGMSCs (GS). Incorporating HUVECs into GHS extended cell viability and stability, initiated the expression of angiogenic factors CD31 and VEGFA, and upregulated the expression of osteogenic factors ALP, OCN, and RUNX2, especially when GHS with a GHR of 1:1. Taken together, GHS, derived from the 3D co-culture of sGMSCs and HUVECs, enhanced osteogenic and angiogenic capacities in vitro, extending the application of cell therapy in bone tissue engineering.

Biomimetic MDSCs membrane coated black phosphorus nanosheets system for photothermal therapy/photodynamic therapy synergized chemotherapy of cancer.

Photothermal therapy is favored by cancer researchers due to its advantages such as controllable initiation, direct killing and immune promotion. However, the low enrichment efficiency of photosensitizer in tumor site and the limited effect of single use limits the further development of photothermal therapy. Herein, a photo-responsive multifunctional nanosystem was designed for cancer therapy, in which myeloid-derived suppressor cell (MDSC) membrane vesicle encapsulated decitabine-loaded black phosphorous (BP) nanosheets (BP@ Decitabine @MDSCs, named BDM). The BDM demonstrated excellent biosafety and biochemical characteristics, providing a suitable microenvironment for cancer cell killing. First, the BDM achieves the ability to be highly enriched at tumor sites by inheriting the ability of MDSCs to actively target tumor microenvironment. And then, BP nanosheets achieves hyperthermia and induces mitochondrial damage by its photothermal and photodynamic properties, which enhancing anti-tumor immunity mediated by immunogenic cell death (ICD). Meanwhile, intra-tumoral release of decitabine induced G2/M cell cycle arrest, further promoting tumor cell apoptosis. In vivo, the BMD showed significant inhibition of tumor growth with down-regulation of PCNA expression and increased expression of high mobility group B1 (HMGB1), calreticulin (CRT) and caspase 3. Flow cytometry revealed significantly decreased infiltration of MDSCs and M2-macrophages along with an increased proportion of CD4+, CD8+ T cells as well as CD103+ DCs, suggesting a potentiated anti-tumor immune response. In summary, BDM realizes photothermal therapy/photodynamic therapy synergized chemotherapy for cancer.

The clinical significance and application of the peri-implant phenotype in dental implant surgery: a narrative review.

Background and Objective: In recent years, the concept of the peri-implant phenotype has become a new standard for the clinical evaluation of the soft and hard tissues surrounding dental implants. Improving this phenotype enhances the likelihood of achieving long-term favorable results and is a necessary consideration during implant planning. Stable peri-implant tissue support is also crucial for the functional and aesthetic value of implant restoration. Herein, the authors review the clinical significance of the peri-implant phenotype and assess the timing of treatment strategies for improving peri-implant phenotype elements. Methods: A literature search was performed to retrieve papers on peri-implant tissue management and clinical outcomes published up to November 24th, 2022 in PubMed, Web of Science, EMBASE, and Scopus. Key Content and Findings: The optimal time to improve peri-implant bone thickness (PBT) is with augmentation procedures before implant surgery or at the same time as first-stage surgery. Similarly, issues associated with keratinized mucosa width (KMW) and mucosal thickness (MT) should be addressed before final restoration. The establishment of supracrestal tissue height (STH) depends on the MT and implant depth of the patient. Furthermore, special attention should be paid to the effect of the peri-implant phenotype on the prognosis of immediate implant placement in the aesthetic zone. Conclusions: The long-term success of implant restoration depends on careful planning that considers appropriate interventions for improving the peri-implant phenotype at different stages of treatment to reduce iatrogenic variables.

Temperature Changes in Oral All-Ceramic Materials with Different Optical Properties under Er:YAG Laser Irradiation.

Objectives: This in vitro study is aimed at assessing the oral all-ceramic materials energy transmission and temperature changes after Er:YAG laser irradiation of monolithic zirconia all-ceramic materials with varying optical properties. Materials and Methods: Two monolithic zirconia materials, Zenostar T and X-CERA TT (monolithic Zirconia), were studied. Specimens were divided into four groups, with a thickness of 1.0, 1.5, 2.0, and 2.5 mm, respectively. The chemical elemental composition of the two materials was determined using X-ray spectroscopy and Fourier transform infrared spectroscopy. The light transmittance of specimens with different thicknesses was measured using a spectrophotometer at three wavelength ranges: 200-380, 380-780, and 780-2500 nm. Irradiation with Er:YAG laser was performed, and the resultant temperature changes were measured using a thermocouple thermometer. Results: Compositional analysis indicated that Si content in X-CERA TT was higher than that in Zenostar T. The light transmittance of both materials decreased as specimen thickness increased. Er:YAG laser irradiation led to temperature increase at both Zenostar T (26.4°C-81.7°C) and X-CERA TT (23.9°C-53.5°C) specimens. Both optical transmittance and temperature changes after Er:YAG laser irradiation were consistent with exponential distribution against different thickness levels. Conclusion: Er:YAG laser penetration energy and resultant temperature changes were mainly determined by the thickness and composition of the examined monolithic zirconia materials.

Impact of High-Altitude Hypoxia on Early Osseointegration With Bioactive Titanium.

Nowadays, the bone osseointegration in different environments is comparable, but the mechanism is unclear. This study aimed to investigate the osseointegration of different bioactive titanium surfaces under normoxic or high-altitude hypoxic environments. Titanium implants were subjected to one of two surface treatments: (1) sanding, blasting, and acid etching to obtain a rough surface, or (2) extensive polishing to obtain a smooth surface. Changes in the morphology, proliferation, and protein expression of osteoblasts on the rough and smooth surfaces were examined, and bone formation was studied through western blotting and animal-based experiments. Our findings found that a hypoxic environment and rough titanium implant surface promoted the osteogenic differentiation of osteoblasts and activated the JAK1/STAT1/HIF-1α pathway in vitro. The animal study revealed that following implant insertion in tibia of rabbit, bone repair at high altitudes was slower than that at low altitudes (i.e., in plains) after 2weeks; however, bone formation did not differ significantly after 4weeks. The results of our study showed that: (1) The altitude hypoxia environment would affect the early osseointegration of titanium implants while titanium implants with rough surfaces can mitigate the effects of this hypoxic environment on osseointegration, (2) the mechanism may be related to the activation of JAK1/STAT1/HIF-1α pathway, and (3) our results suggest the osteogenesis of titanium implants, such as oral implants, is closely related to the oxygen environment. Clinical doctors, especially dentists, should pay attention to the influence of hypoxia on early osseointegration in patients with high altitude. For example, it is better to choose an implant system with rough implant surface in the oral cavity of patients with tooth loss at high altitude.

Inhibition of Cathepsin K Alleviates Autophagy-Related Inflammation in Periodontitis-Aggravating Arthritis.

Rheumatoid arthritis (RA) and periodontitis share many epidemiological and pathological features, with emerging studies reporting a relationship between the two diseases. Recently, RA and periodontitis have been associated with autophagy. In the present study, we investigated the effects of cathepsin K (CtsK) inhibition on RA with periodontitis in a mouse model and its immunological function affecting autophagy. To topically inhibit CtsK periodontitis with arthritis in the animal model, adeno-associated virus (AAV) transfection was performed in periodontal and knee joint regions. Transfection of small interfering RNA (siRNA) was performed to inhibit CtsK in RAW264.7 cells. The effects of CtsK inhibition on the autophagy pathway were then evaluated in both in vivo and in vitro experiments. RA and periodontitis aggravated destruction and inflammation in their respective lesion areas. Inhibition of CtsK had multiple effects: (i) reduced destruction of alveolar bone and articular tissue, (ii) decreased macrophage numbers and inflammatory cytokine expression in the synovium, and (iii) alleviated expression of the autophagy-related transcription factor EB (TFEB) and microtubule-associated protein 1A/1B-light chain 3 (LC3) at the protein level in knee joints. Inhibition of CtsK in vitro reduced the expression of autophagy-related proteins and related inflammatory factors. Our data revealed that the inhibition of CtsK resisted the destruction of articular tissues and relieved inflammation from RA with periodontitis. Furthermore, CtsK was implicated as an imperative regulator of the autophagy pathway in RA and macrophages.

Inhibition of Ctsk modulates periodontitis with arthritis via downregulation of TLR9 and autophagy.

OBJECTIVES: The mechanisms underlying the effects of Toll-like receptor 9 (TLR9) and autophagy on rheumatoid arthritis (RA)-aggravated periodontitis are unclear. We aimed to explore a novel target, cathepsin K (Ctsk)-mediated TLR9-related autophagy, during the progress of periodontitis with RA. MATERIALS AND METHODS: DBA/J1 mouse model of periodontitis with RA was created by local colonization of Porphyromonas gingivalis (Pg) and injection of collagen. The expression of Ctsk was inhibited by adeno-associated virus (AAV). Micro-CT, immunohistochemistry (IHC), Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect the expression of TLR9-related autophagy in periodontitis with RA. Small interfering RNA (siRNA) and CpG oligodeoxynucleotides (CpG ODN) were applied in macrophages. Western blot, immunofluorescence (IF) and qRT-PCR were used to verify the in vivo results. RESULTS: RA can promote periodontitis bone destruction in the lesion area, while inhibiting Ctsk could effectively alleviate this effect. The infiltration of macrophages, TLR9, autophagy proteins (TFEB and LC3) and inflammatory cytokines increased in the periodontitis-with-RA group and was reduced by the inhibition of Ctsk in the periodontal region. Macrophage stimulation confirmed the in vivo results. With the activation of TLR9 by CpG ODN, inhibition of Ctsk could suppress both TLR9 downstream signalling proteins and autophagy-related proteins. CONCLUSIONS: This study advanced a novel role for Ctsk in TLR9 and autophagy to explain the interaction between periodontitis and RA.

Inhibition of Ctsk alleviates periodontitis and comorbid rheumatoid arthritis via downregulation of the TLR9 signalling pathway.

AIM: In this study, we investigate the mechanistic link between rheumatoid arthritis (RA) and periodontitis to identify a novel target (cathepsin K; Ctsk) for the treatment of comorbid periodontitis and RA. METHODS: An experimental model of periodontitis with arthritis was established in DBA/1 mice. We then tested the effect of BML-244, a specific inhibitor of Ctsk, by quantifying several inflammatory markers of TLR9 signalling both in vivo and in vitro. RESULTS: Our results showed that periodontitis-rheumatoid arthritis comorbidity causes severer periodontal bone and joint cartilage destruction than either disease alone. Inhibition of Ctsk reduced infiltration by dendritic cells and T cells and inflammatory cytokine production; these improvements alleviated the hard-tissue erosion in periodontitis and RA as measured by bone erosion in periodontal lesions and cartilage destruction in knee joints. Inhibition of Ctsk also decreased the expression of TLR4 and TLR9 in vivo, whereas in vitro experiments indicated that Ctsk is involved specifically in the production of cytokines in response to TLR9 engagement. CONCLUSION: Our data reveal that periodontitis and RA may have additive pathological effects through dysregulation of the TLR9 pathway and that Ctsk is a critical mediator of this pathway and contributes to the pathogenesis of RA and periodontitis.