Spheroid Coculture of Human Gingiva-Derived Progenitor Cells With Endothelial Cells in Modified Platelet Lysate Hydrogels

Mitochondrial ROS participates in Porphyromonas gingivalis-induced pyroptosis in cementoblasts

This study aimed to investigate correlation between mitochondrial reactive oxygen species and Porphyromonas gingivalis in the process of cementoblast pyroptosis. Lactate dehydrogenase activity assay, enzyme-linked immunosorbent assay, western blotting and flow cytometry analysis were utilized to explore whether Porphyromonas gingivalis triggered pyroptosis in cementoblasts. Reactive oxygen species and mitochondrial reactive oxygen species were detected using flow cytometry and fluorescence staining. The effect of mitochondrial reactive oxygen species on the Porphyromonas gingivalis-induced pyroptosis of cementoblasts was assessed by Mito-Tempo, mitochondrion-targeted superoxide dismutase mimetic. Phosphorylation levels of p65 were measured by western blotting. SC75741, a nuclear factor-kappa B inhibitor, was added to block the nuclear factor-kappa B in the Porphyromonas gingivalis-infected cementoblasts. Porphyromonas gingivalis triggered pyroptosis of cementoblasts, and an elevation in reactive oxygen species generation in the mitochondria was observed. Inhibition of mitochondrial reactive oxygen species reduced pyroptosis and nuclear factor-kappa B signaling pathway mediated the pyroptotic cell death in Porphyromonas gingivalis-infected cementoblasts. Together, our findings demonstrate that mitochondrial reactive oxygen species increased by Porphyromonas gingivalis participated in the pyroptosis of cementoblasts. Targeting mitochondrial reactive oxygen species may offer therapeutic strategies for root surface remodeling or periodontal regeneration.

Engineering pre-vascularized 3D tissue and rapid vascular integration with host blood vessels via co-cultured spheroids-laden hydrogel

Recent advances in regenerative medicine and tissue engineering have enabled the biofabrication of three-dimensional (3D) tissue analogues with the potential for use in transplants and disease modeling. However, the practical use of these biomimetic tissues has been hindered by the challenge posed by reconstructing anatomical-scale micro-vasculature tissues. In this study, we suggest that co-cultured spheroids within hydrogels hold promise for regenerating highly vascularized and innervated tissues, bothin vitroandin vivo. Human adipose-derived stem cells (hADSCs) and human umbilical vein cells (HUVECs) were prepared as spheroids, which were encapsulated in gelatin methacryloyl hydrogels to fabricate a 3D pre-vascularized tissue. The vasculogenic responses, extracellular matrix production, and remodeling depending on parameters like co-culture ratio, hydrogel strength, and pre-vascularization time forin vivointegration with native vessels were then delicately characterized. The co-cultured spheroids with 3:1 ratio (hADSCs/HUVECs) within the hydrogel and with a pliable storage modulus showed the greatest vasculogenic potential, and ultimately formedin vitroarteriole-scale vasculature with a longitudinal lumen structure and a complex vascular network after long-term culturing. Importantly, the pre-vascularized tissue also showed anastomotic vascular integration with host blood vessels after transplantation, and successful vascularization that was positive for both CD31 and alpha-smooth muscle actin covering 18.6 ± 3.6μm2of the luminal area. The described co-cultured spheroids-laden hydrogel can therefore serve as effective platform for engineering 3D vascularized complex tissues.

Chroogomphus rutilus Regulates Bone Metabolism to Prevent Periodontal Bone Loss during Orthodontic Tooth Movement in Osteoporotic Rats

Osteoporosis (OP) leads to the acceleration of tooth movement and aggravation of periodontal bone loss during orthodontic treatment. Chroogomphus rutilus (CR) is abundant in nutrients and demonstrates remarkable antioxidant and anti-inflammatory properties. In the present study, the components of CR, including 35.00% total sugar, 0.69% reducing sugar, 14.40% crude protein, 7.30% total ash, 6.10% crude fat, 0.51% total flavonoids, 1.94% total triterpenoids, 0.32% total sterol, 1.30% total saponins, 1.69% total alkaloids, and 1.02% total phenol, were first systematically examined, followed by an investigation into its regulatory effects on bone metabolism in order to mitigate bone loss during orthodontic tooth movement in osteoporotic rats. The results of the imaging tests revealed that CR treatment reduced periodontal bone loss and normalized tooth movement in the OP. In conjunction with analyses of intestinal flora and metabolomics, CR enhances the prevalence of anti-inflammatory genera while reducing the production of inflammatory metabolites. Meanwhile, CR reduced the levels of periodontal inflammatory factors, including TNF-α, IL-1β, and IL-6, by activating Wnt/β-catenin signaling, and promoted periodontal bone formation. These findings imply that CR is a potent supplementary therapy for controlling periodontal bone remodeling in patients with OP undergoing orthodontic treatment.

Calvaria defect regeneration via human periodontal ligament stem cells and prevascularized scaffolds in athymic rats

BACKGROUND

Vascularization plays an important role in dental and craniofacial regenerations. Human periodontal ligament stem cells (hPDLSCs) are a promising cell source and, when co-cultured with human umbilical vein endothelial cells (hUVECs), could promote vascularization. The objectives of this study were to develop a novel prevascularized hPDLSC-hUVEC-calcium phosphate construct, and investigate the osteogenic and angiogenic efficacy of this construct with human platelet lysate (hPL) in cranial defects in rats for the first time.

METHODS

hPDLSCs and hUVECs were co-cultured on calcium phosphate cement (CPC) scaffolds with hPL. Cell proliferation, angiogenic gene expression, angiogenesis, alkaline phosphatase activity, and cell-synthesized minerals were determined. Bone and vascular regenerations were investigated in rat critical-sized cranial defects in vivo.

RESULTS

hPDLSC-hUVEC-CPC-hPL group had 2-fold greater angiogenic expressions and cell-synthesized mineral synthesis than hPDLSC-hUVEC-CPC group (p < 0.05). Microcapillary-like structures were formed on scaffolds in vitro. hPDLSC-hUVEC-CPC-hPL group had more vessels than hPDLSC-hUVEC-CPC group (p < 0.05). In cranial defects in rats, hPDLSC-hUVEC-CPC-hPL group regenerated new bone amount that was 2.1 folds and 4.0 folds, respectively, that of hPDLSC-hUVEC-CPC group and CPC control (p < 0.05). New blood vessel density of hPDLSC-hUVEC-CPC-hPL group was 2 folds and 7.9 folds, respectively, that of hPDLSC-hUVEC-CPC group and CPC control (p < 0.05).

CONCLUSION

The hPL pre-culture method is promising to enhance bone regeneration via prevascularized CPC. Novel hPDLSC-hUVEC-CPC-hPL prevascularized construct increased new bone formation and blood vessel density by 4-8 folds over CPC control.

CLINICAL SIGNIFICANCE

Novel hPDLSC-hUVEC-hPL-CPC prevascularized construct greatly increased bone and vascular regeneration in vivo and hence is promising for a wide range of craniofacial applications.

Fabrication of hydroxyapatite reinforced polymeric hydrogel membrane for regeneration

Background

The regeneration of lost/damaged support tissue in the periodontium, including the alveolar bone, periodontal ligament, and cementum, is an ambitious purpose of periodontal regenerative therapy and might effectively reduce periodontitis-caused tooth loss. Guided tissue regeneration (GTR) is a technique currently used in dentistry for periodontal surgery, which allows osseous regeneration prior to soft tissue migration into the area of interest. Calcium phosphate-based bone grafts (mostly Tricalcium Phosphate or Hydroxyapatite) are bio ceramics that show the greatest similarity to the mineral found in the bone. Thereby, giving calcium-phosphate excellent biocompatibility, biodegradability and osteoconductivity. The aim of the study is to fabricate hydroxyapatite reinforced polymeric hydrogel membrane for regeneration.

Materials and Method

Pure alginate fabrication was done by cross linking sodium alginate with calcium chloride. Hydroxyapatite (HAP) alginate (Alg) was formulated by adding nanoparticles to the alginate mixture, which was then cross-linked with calcium chloride to formulate a HAP alginate polymeric membrane. The Fourier-transform infrared spectroscopy (FT-IR), Scanning Electron Microscope (SEM), and biocompatibility tests were performed to analyse the membrane characteristics.

Results

Fabricated Hydroxyapatite- alginate (Hap- Alg) membrane has longer durability, because of strong crystal structure which in turn might take a longer time to regenerate. The membrane was found to be biocompatible and HAp induces faster mineralisation which in turn will increase the tissue regeneration rate of the membrane.

Conclusion

The findings of our study suggests that the HAP-Alg hydro gel membrane is highly durable and hemocompatible and it has faster mineralisation capability thus making it superior from the clinically available membranes for GTR. Further analyses needs to be conducted to evaluate the potential of this membrane to be used for regeneration.

Hydrogel supplemented with human platelet lysate enhances multi-lineage differentiation of mesenchymal stem cells

Stem cells from human exfoliated deciduous teeth (SHED) can be used as a potential clinical material. But the use of xenogeneic ingredients will increase the risk of zoonotic disease transmission. Human platelet lysate (HPL) is a potential surrogate and used in human cell expansion with reliability in clinical applications. In this study, we synthesized chitosan/gelatin/gellan gum hydrogel supplemented with HPL and investigated the effect of 3D culture for SHED. TMT-tagged proteomics was used to decipher the secretome protein profiles of SHEDs and a total of 3209 proteins were identified, of which 23 were up-regulated and 192 were down-regulated. The results showed that hydrogel supplemented with HPL promoted SHED proliferation. After induction, the hydrogel coating contributed to osteogenic differentiation, adipogenic differentiation and differentiation into neural-like cells of SHED. SHED encapsulated in a hydrogel promotes migration and angiogenesis of HUVEC. In conclusion, our research found that hydrogel supplemented with HPL can be used as a method for SHED in standardized production and can contribute to the clinical application of SHED in cell therapy.

Heterotypic Multicellular Spheroids as Experimental and Preclinical Models of Sprouting Angiogenesis

Sprouting angiogenesis is the common response of live tissues to physiological and pathological angiogenic stimuli. Its accurate evaluation is of utmost importance for basic research and practical medicine and pharmacology and requires adequate experimental models. A variety of assays for angiogenesis were developed, none of them perfect. In vitro approaches are generally less physiologically relevant due to the omission of essential components regulating the process. However, only in vitro models can be entirely non-xenogeneic. The limitations of the in vitro angiogenesis assays can be partially overcome using 3D models mimicking tissue O2 and nutrient gradients, the influence of the extracellular matrix (ECM), and enabling cell-cell interactions. Here we present a review of the existing models of sprouting angiogenesis that are based on the use of endothelial cells (ECs) co-cultured with perivascular or other stromal cells. This approach provides an excellent in vitro platform for further decoding of the cellular and molecular mechanisms of sprouting angiogenesis under conditions close to the in vivo conditions, as well as for preclinical drug testing and preclinical research in tissue engineering and regenerative medicine.