Bioreactor design for the mechanical stimulation by compression of 3D cell cultures

Bioreactors with a controlled physiological environment are being developed to study various cell processes. The influences of mechanostimulation on bone cell cultures can be investigated using a compression bioreactor. The developed bioreactor system applies a cyclic compression force to the specimen via an eccentrically mounted push rod. The compression force is monitored by a force sensor to detect changes in the material properties of the specimen. Depending on the piston setting, a stroke of 0.28 - 2.50 mm can be applied to the specimen. The bioreactor system was tested with a trial run of 18 days. A sample was continuously stimulated with a loading frequency of 2 Hz and a stroke of 1.50 mm. The sterility in the cell chamber as well as the functionality of the realised bioreactor stimulation system could be successfully confirmed

Effects of Low Intensity Pulsed Ultrasound And Low Level Heat on Bone Cells

Both Low Intensity Pulsed UltraSound (LIPUS) and low level heat have separately been shown to improve mineralization in bone cell cultures (Unsworth et al 2007, Leon et al 1993). This study examines the effect of concurrent LIPUS and low level heat on MC3T3-E1 bone cell cultures. The treatment groups were: LIPUS, heat, LIPUS + heat, and control. The LIPUS intensity was ISATA=10 mW/cm2 at f=1.5 MHz, and heat was applied at 40ºC for 40 minutes each day over 15 days. The LIPUS + heat group received the treatments concurrently. The groups were compared using Alizarin Red staining to measure the degree of cell mineralization. All treatment groups showed statistically significantly improved mineralization over the control; however, there was no statistical difference between the LIPUS and the LIPUS + heat groups. Early results suggest that concurrent heat and LIPUS on MC3T3-E1 bone cells has no additive effect on mineralization.

Effects of Low Intensity Pulsed Ultrasound And Low Level Heat on Bone Cells

Both Low Intensity Pulsed UltraSound (LIPUS) and low level heat have separately been shown to improve mineralization in bone cell cultures (Unsworth et al 2007, Leon et al 1993). This study examines the effect of concurrent LIPUS and low level heat on MC3T3-E1 bone cell cultures. The treatment groups were: LIPUS, heat, LIPUS + heat, and control. The LIPUS intensity was ISATA=10 mW/cm2 at f=1.5 MHz, and heat was applied at 40ºC for 40 minutes each day over 15 days. The LIPUS + heat group received the treatments concurrently. The groups were compared using Alizarin Red staining to measure the degree of cell mineralization. All treatment groups showed statistically significantly improved mineralization over the control; however, there was no statistical difference between the LIPUS and the LIPUS + heat groups. Early results suggest that concurrent heat and LIPUS on MC3T3-E1 bone cells has no additive effect on mineralization.

Effect of hyaluronic acid on osteoblast function in vivo and on fracture healing in an experimental rabbit model

Background Fracture healing is regulated by endocrine hormones and biochemical and biophysical factors, including hyaluronic acid (HA), which is a component of the extracellular matrix. The prerequisites for biological responses that promote fracture healing, such as biomechanical conditions, and molecular factors, can be investigated in bone cell cultures. Methods In cell experiments, CCK-8 was used to detect the effect of different concentrations of HA on MC3T3-E1 cells after cell intervention. After 10% of HA interfered with MC3T3-E1 cells, they were cultured in induction medium and observed for their mineralization Impact. Total protein was extracted from cells to observe Runx2 and OCN protein expression. After successful modeling in animal experiments, X-rays of the fracture site were taken to determine bone density at the fracture end. After the fracture site was taken, histological examination was performed and the callus was analyzed quantitatively and qualitatively. Results In this study, HA promoted the formation of calcium nodules and the expression of runt-related transcription factor (Runx)2 and osteocalcin (OCN) proteins in MC3T3-E1 cells; In a rabbit tibial fracture model, HA promoted formation of larger calluses than those in control or sham-treated animals at 2, 4, 6, and 8 weeks ( P < 0.05). Osteophytes were larger in HA-treated than in control animals at 4 and 6 weeks ( P < 0.05). Bone mineral density was greater in HA-treated than in control animals at 4, 6, and 8 weeks ( P < 0.05). Conclusions The results showed that HA promoted the formation of calcified nodules in bone cell cultures and healing of rabbit tibial fractures.

Effect of hyaluronic acid on osteoblast function in vivo and on fracture healing in an experimental rabbit model

Background: Fracture healing is regulated by endocrine hormones and biochemical and biophysical factors, including hyaluronic acid (HA), which is a component of the extracellular matrix. The prerequisites for biological responses that promote fracture healing, such as biomechanical conditions, and molecular factors, can be investigated in bone cell cultures. Methods: In this study, HA promoted the formation of calcium nodules and the expression of runt-related transcription factor (Runx)2 and osteocalcin (OCN) proteins in MC3T3-E1 cells. Results: In a rabbit tibial fracture model, HA promoted formation of larger calluses than those in control or sham-treated animals at 2, 4, 6, and 8 weeks (P < 0.05). Osteophytes were larger in HA-treated than in control animals at 4 and 6 weeks (P < 0.05). Bone mineral density was greater in HA-treated than in control animals at 4, 6, and 8 weeks (P < 0.05). Conclusions: The results showed that HA promoted the formation of calcified nodules in bone cell cultures and healing of rabbit tibial fractures.