Simvastatin Induces In Vitro Mineralization Effects of Primary Human Odontoblast-Like Cells

Simvastatin-Loaded Chitosan Microspheres as a Biomaterial for Dentin Tissue Engineering

In the present study, chitosan microspheres (MSCH) loaded with different concentrations of simvastatin (2%, 5%, and 10%) were synthesized as a biomaterial for dentin tissue engineering. The microspheres were prepared by emulsion crosslinking method, and simvastatin was incorporated during the process. The microspheres were then physicochemically and morphologically characterized. Scanning electron microscopy and infrared spectroscopy confirmed the spherical morphology of synthesized microspheres and the chemical incorporation of simvastatin into MSCH, respectively. UV-visible absorption confirmed the controlled and continuous release pattern of the drug. To mimic the clinical application in vitro, the microspheres were applied onto three-dimensional (3D) cultures of human dental pulp cells (HDPCs). Cell viability, proliferation, and in situ-mineralized matrix deposition were evaluated. The results indicated no cytotoxic effects for all 3D cultures for all tested biomaterials, with cells being able to proliferate significantly over time. HDPCs showed a significant increase in the deposition of mineralization nodules when 3D cultures were in direct contact with chitosan microspheres in comparison to control; nevertheless, the highest expression was observed for MSCH encapsulated with 5% and 10% simvastatin, which was significantly higher than plain MSCH. Therefore, chitosan microsphere systems loaded with 5%-10% simvastatin provided the development of a controlled release system in bioactive dosages for dentin tissue engineering.

Statins-Their Role in Bone Tissue Metabolism and Local Applications with Different Carriers

Statins, widely prescribed for lipid disorders, primarily target 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase competitively and reversibly, resulting in reduced low-density lipoprotein cholesterol (LDL-C). This mechanism proves effective in lowering the risk of lipid-related diseases such as ischemic cerebrovascular and coronary artery diseases. Beyond their established use, statins are under scrutiny for potential applications in treating bone diseases. The focus of research centers mainly on simvastatin, a lipophilic statin demonstrating efficacy in preventing osteoporosis and aiding in fracture and bone defect healing. Notably, these effects manifest at elevated doses (20 mg/kg/day) of statins, posing challenges for systematic administration due to their limited bone affinity. Current investigations explore intraosseous statin delivery facilitated by specialized carriers. This paper outlines various carrier types, characterizing their structures and underscoring various statins' potential as local treatments for bone diseases.

Cytotoxicity and induced apoptosis of a new bioceramic cement containing simvastatin on stem cells from human exfoliated deciduous teeth

BACKGROUND

This study aims to compare cytotoxicity and induced apoptosis of a new bioceramic cement containing different concentrations of simvastatin on stem cells from human exfoliated deciduous teeth (SHED).

MATERIALS AND METHODS

This research was an in vitro study. To evaluate the cytotoxicity and induced apoptosis of the bioceramic cement containing different concentrations of simvastatin, the SHED were exposed to the cement during 1, 3, and 7 days. Pure bioceramic cement and pure simvastatin with concentrations of 1, 0.1, and 0.01 μM were also tested to evaluate the possible synergic effect. Mineral trioxide aggregate (MTA) as the gold standard of pulp dressing materials was compared. MTT assay and Annexin V assay were used to evaluate cytotoxicity and induced apoptosis, respectively. The data were analyzed using ANOVA and Tukey post hoc tests at the significance level of 0.05.

RESULTS

During 7 days, MTA, bioceramic cement, simvastatin 0.1 and 0.01 μM, and bioceramic cement containing 0.1 and 0.01 μM simvastatin increased (P < 0.05) and simvastatin with concentration of 1 μM decreased the cell viability (P < 0.05). Except for MTA and bioceramic cement containing 0.1 and 0.01 μM simvastatin, all other compounds induced apoptosis within 7 days (P < 0.05).

CONCLUSION

After 7 days, the viability of the SHED in the presence of a new bioceramic cement containing 0.1 and 0.01 μM simvastatin was not compromised. Moreover, this cement showed superior results than MTA and provided an environment for cell proliferation. This finding appears to be due to the pharmacological effects of low concentrations of simvastatin.

Human Primary Odontoblast-like Cell Cultures—A Focused Review Regarding Cell Characterization

Cell cultures can provide useful in vitro models. Since odontoblasts are postmitotic cells, they cannot be expanded in cell cultures. Due to their extension into the dentin, injuries are inevitable during isolation. Therefore, “odontoblast-like” cell culture models have been established. Nowadays, there is no accepted definition of odontoblast-like cell cultures, i.e., isolation, induction, and characterization of cells are not standardized. Furthermore, no quality-control procedures are defined yet. Thus, the aim of this review was to evaluate both the methods used for establishment of cell cultures and the validity of molecular methods used for their characterization. An electronic search was performed in February 2022 using the Medline, Scopus, and Web of Science database identifying publications that used human primary odontoblast-like cell cultures as models and were published between 2016 and 2022. Data related to (I) cell culture conditions, (II) stem cell screening, (III) induction media, (IV) mineralization, and (V) cell characterization were analyzed. The included publications were not able to confirm an odontoblast-like nature of their cell cultures. For their characterization, not only a similarity to dentin but also a distinction from bone must be demonstrated. This is challenging, due to the developmental and evolutionary proximity of these two tissue types.

Pleiotropic effects on proliferation and mineralization of primary human adipose tissue-derived stromal cells induced by simvastatin

The circulating low-density lipoprotein concentration in blood can be reduced by the administration of statins. Frequently simvastatin (SV) is prescribed. Due to the reported pleiotropic effects of SV the aim of this study was to evaluate mineralization effects on human adipose tissue-derived stromal cells upon administration of SV. After informed consent human adipose tissue-derived stromal cells were obtained from tissue surplus of regular treatments of 14 individuals. According to established protocols after adding various SV concentrations (0.01 µM, 0.1 µM, 1.0 µM, 2.0 µM), alkaline phosphate (osteoblastic marker), mineralization capability and viability were determined at day 18, 21 and 28. The Kruskal-Wallis test was performed for statistical analysis. After adding SV a dose-dependent significant decreased viability and levels of alkaline phosphatase (p < 0.01) and a significantly increased mineralization (p < 0.01) of the primary cultures was recognized during the late mineralization stage. Mineralization of the human adipose tissue-derived stromal cells was induced by SV, possibly originated from alternative pathways than the alkaline phosphatase pathway. Further investigations should be performed regarding switching into the osteoblastic differentiation and as a possible source of cells that can be used as the basis for a potential bone graft substitute, which may allow an extension of the field of application.