Nutritional deprivation and LPS exposure as feasible methods for induction of cellular - A methodology to validate for vitro photobiomodulation studies

Cost-effective production of meaty aroma from porcine cells for hybrid cultivated meat

Cultivated meats are typically hybrids of animal cells and plant proteins, but their high production costs limit their scalability. This study explores a cost-effective alternative by hypothesizing that controlling the Maillard and lipid thermal degradation reactions in pure cells can create a meaty aroma that could be extracted from minimal cell quantities. Using spontaneously immortalized porcine myoblasts and fibroblasts adapted to suspension culture with a 1 % serum concentration, we developed a method to isolate flavor precursors via freeze-thawing. Thermal reaction conditions were optimized to enhance aroma compound production. Chemical profiling demonstrates that myoblasts produce an aroma profile closer to pork meat than fibroblasts, although serum reduction decreased aroma yield. Sensory analysis supported these findings. Incorporating the optimized aroma extract - derived from just 1.2 % (w/w) cells - into plant proteins resulted in a hybrid cultivated meat with 78.5 % sensory similarity to pork meat, but with a significant 80 % reduction in production costs.

A Biomimetic Approach to Diode Laser Use in Endodontic Treatment of Immature Teeth: Thermal, Structural, and Biological Analysis

The root walls of immature permanent teeth are often weak, thin, and short, making regenerative endodontic treatment (RET) necessary. The goal of RET is to create a favorable environment for further root development. A biomimetic approach is essential for thorough disinfection, followed by the preservation and potential stimulation of stem cells from surrounding tissue to enable root regeneration and continued development. The objective of this study was to assess temperature changes on the external root surface, structural alterations in the internal root walls following irradiation with a 940 nm diode laser, and the biocompatibility of stem cells from the apical papilla (SCAPs). Irradiation was performed with varying output powers (0.5 W, 1 W, 1.5 W, and 2 W) in continuous mode for 5 s over four consecutive cycles. Thermographic measurements during irradiation, the micro-CT analysis of root samples, and mitochondrial activity of SCAPs were evaluated. The heating effect correlated directly with a higher output power and thinner root walls. A 1 W output power was found to be safe for immature teeth, particularly in the apical third of the root, while 1.5 W could be safely used for mature mandibular incisors. Diode laser irradiation at 1 W and 1.5 W significantly stimulated SCAPs' mitochondrial activity within 24 h post-irradiation, indicating a potential photobiostimulatory effect. However, no significant changes were observed at lower (0.5 W) and higher (2 W) output powers. The area of open tubular space inside the root canal was significantly reduced after irradiation, regardless of the applied power. Additionally, irradiation contributed to the demineralization of the dentin on the inner root walls. Future studies should explore the impact of irrigants used between irradiation cycles, the potential benefits of conical laser tips for more even energy distribution, and a thorough analysis of how disinfection protocols affect both the dentin structure and stem cell viability.

"Metabolism of Odontoblast-like cells submitted to transdentinal irradiation with blue and red LED"

OBJECTIVES

The present study evaluated the trans-dentinal effect of light emitting diodes (LEDs) irradiation on the metabolism of odontoblast-like cells.

METHODS

Seventy-two dentin discs (0.2mm thick) were obtained from human molar teeth. MDPC-23 cells (20,000 cells/disc) were seeded on the pulpal side of the discs using DMEM, supplemented with 10% fetal bovine serum (FBS). After 12h, the culture medium was replaced with DMEM containing 0.5% FBS. After additional 12h, blue (455±10nm) or red (630±10nm) LEDs were used at irradiances of 80 and 40mW/cm², respectively, to irradiate the occlusal side of the discs. The energy doses were fixed at 2 or 4J/cm². Cell viability, alkaline phosphatase activity (ALP), total protein production and collagen synthesis were evaluated 72h after irradiation. Data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05).

RESULTS

Red light promoted proliferative effects at the energy dose of 4J/cm²_. Conversely, cell cultures irradiated with 2J/cm² emitted by the blue light showed reduced viability. ALP production was stimulated by red light in comparison with blue light at 4J/cm². Total protein production was reduced after exposure to blue light at 4J/cm², while no effect was observed on collagen production.

CONCLUSIONS

Irradiation with red LED at 4J/cm² bio-stimulated the viability of odontoblast-like cells, whilst blue light had unfavorable effects on the cellular metabolism.

Investigation of photobiomodulation potentiality by 635 and 809 nm lasers on human osteoblasts

Photobiomodulation (PBM) describes light-induced photochemical reactions achieved by the application of red or near infrared lasers/LED light with low energy densities. This noninvasive and painless method has been used in some clinical areas but controversial outcomes demand a skeptical look for its promising and potential effects. In this detailed in vitro study, the osteoblast cells were irradiated with 635 and 809 nm diode lasers at energy densities of 0.5, 1, and 2 J/cm². Cell viability, proliferation, bone formation, and osteoblast differentiation were evaluated by methylthiazole tetrazolium (MTT) assay, Alamar Blue assay, acridine orange/propidium iodide staining, alkaline phosphatase (ALP) activity, Alizarin red staining, and reverse-transcription polymerase chain reaction (RT-PCR) to test the expression of collagen type I, ALPL, and osteocalcin. The results indicate that studied energy doses have a transient effect (48 h after laser irradiation) on the osteoblast viability and proliferation. Similarly, laser irradiation did not appear to have any effect on ALP activity. These results were confirmed by RT-PCR analysis of osteoblast markers. This study suggests that several irradiation parameters and variations in the methods should be clearly established in the laboratory before laser treatment becomes a postulated application for bone tissue regeneration in clinical level.