Mindaugas Pranskunas

Polycaprolactone (PCL) and bioactive glass 45S5 (BG) are widely employed within bone tissue engineering due to their mutually complementary properties: PCL contributes structural integrity and biodegradability, whereas BG imparts osteoinductive properties to the composite. While patient-specific bulk scaffolds can restore structural defects, their fabrication requires individualized imaging, design, and manufacturing, increasing both time and cost. Hydrogels offer better conformity to irregular geometries but often lack sufficient mechanical stability and usually degrade rapidly. Microparticle-based systems represent a shape-adaptive alternative that can conform to complex defect geometries without customization, while maintaining structural integrity. In this study, PCL/BG microparticles (MPs) were fabricated using the emulsion solvent evaporation method and evaluated in vitro . The microparticles supported adhesion and spreading, maintaining cell-cell and cell-particle interactions for over a month. Periosteum mesenchymal stem cells cultured on the MPs were responsive to adipogenic and osteogenic induction, as evidenced by increased expression of lineage-specific genes under both conditions. Overall, these findings suggest that PCL/BG microparticles are biocompatible and capable of guiding stem cell differentiation, supporting their potential use in bone regeneration strategies.

Objectives: Millions of people worldwide are affected by diseases or injuries which lead to bone/tooth loss and defects. While such clinical situations are daily practice in most of the hospitals, the widely used treatment methods still have disadvantages. Therefore, this field of medicine is actively searching new tissue regeneration techniques, one of which could be stem cell secretome. Thus, the purpose of this research study was to perform the detail proteomic analysis of periosteum-derived mesenchymal stem cells secretome in order to evaluate if it is capable to induce osteo-regenerative process. Material and Methods: Periosteum-derived mesenchymal stem cells (PMSCs) were extracted from adult male New Zealand White rabbits. Cells were characterised by evaluating their differentiation potential. After characterisation PMSCs secretomes were collected and their proteomic analysis was performed. Results: PMSCs were extracted from adult male New Zealand White rabbits. In order to characterise the extracted PMSCs, they were differentiated in the directions which mainly describes MSC multipotency - osteogenic, myogenic and adipogenic. A total of 146 proteins were detected. After characterisation PMSCs secretomes were collected and their proteomic analysis was performed. The resulting protein composition indicates the ability to promote bone regeneration to fully mature bone. Conclusions: Bioactive molecules detected in periosteum-derived mesenchymal stem cells secretome initiates the processes required for the formation of a fully functional bone.

The mesenchymal stem cell (MSC) secretome has been considered an innovative therapeutic biological approach, able to modulate cellular crosstalk and functionality for enhanced tissue repair and regeneration. This study aims to evaluate the functionality of the secretome isolated from periosteum-derived MSCs, from either basal or osteogenic-induced conditions, in the healing of a critical size calvarial bone defect in the rabbit model. A bioceramic xenograft was used as the vehicle for secretome delivery, and the biological response to the established biocomposite system was assessed by clinical, histological, histomorphometric, and microtomographic analysis. A comparative analysis revealed that the osteogenic-induced secretome presented an increased diversity of proteins, with emphasis on those related to osteogenesis. Microtomographic and histological morphometric analysis revealed that bioceramic xenografts implanted with secretomes enhanced the new bone formation process, with the osteogenic-induced secretome inducing the highest bone tissue formation. The application of the MSC secretome, particularly from osteogenic-induced populations, may be regarded as an effective therapeutic approach to enhance bone tissue healing and regeneration.

To evaluate the reported literature on the use of stem cells or growth factors for post extraction treatment of the alveolar bone.

To systematically examine influence of soft tissue condition and plaque accumulation around dental implants on peri-implantitis development. An electronic literature search was conducted of two databases - MEDLINE (Ovid) and EMBASE from 2011 to 2016. Sequential screenings at the title, abstract, and full-text levels were performed. Clinical human studies in the English language that had reported soft tissue condition or plaque accumulation influence on peri-implantitis development were included. The resulting articles were independently subjected to clear inclusion and exclusion criteria by two reviewers as follows. The search resulted in 8 articles meeting the inclusion criteria. These studies reported gingival index, plaque index, pocket depth, bleeding on probing/modified bleeding index for sites with "adequate" (≥ 2 mm) and "inadequate" (< 2 mm) width of keratinized mucosa. Results demonstrated that the amount of keratinized mucosa has little influence on soft-tissue inflammation in the presence of good oral hygiene. However, suboptimal oral hygiene due to difficulty in access for plaque control in the areas of minimal keratinized mucosa may lead to greater tissue damage. In cases with insufficient keratinized gingiva in the vicinity of implants, the insufficiency does not necessarily mediate adverse effects on the hygiene management and soft tissue health condition. Nonetheless, the risk of the increase of gingival index, plaque index, pocket depth, bleeding on probing/modified bleeding index is present. Therefore, the presence of an appropriate amount of keratinized gingiva is required.