Purpose: To assess the effect of external mechanical microstimuli of controlled magnitude on the microarchitecture of the peri-implant bone beds in rat tibiae.
Materials And Methods: Tibiae of forty rats were fitted with two transcutaneous titanium cylinders. After healing, the implants were loaded to 1 to 3 N, five days/week for four weeks. These force levels translated into intraosseous strains of 700 ± 200 με, 1400 ± 400 με, and 2100 ± 600 με. After sacrifice, the implants' pullout strength was assessed. Second, the bone's microarchitecture was analyzed by microcomputed tomography (μCT) in three discrete regions of interest (ROIs). Third, the effect of loading on bone material properties was determined by nanoindentation.
Results: The trabecular BV/TV significantly increased in an ROI of 0.98 mm away from the test implant in the 1 N versus the 3 N group with an opposite trend for cortical thickness. Pull-out strength significantly increased in the 2 N relatively to the nonstimulated group. Higher values of E-modulus and hardness were observed in the trabecular bone of the 2 N group.
Conclusion: The in vivo mechanical loading of implants induces load-dependent modifications in bone microarchitecture and bone material properties in rat tibiae. In pull-out strength measurements, implant osseointegration was maximized at 2 N (1400 ± 400 με).
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3866820 | PMC |
http://dx.doi.org/10.1155/2013/234093 | DOI Listing |
Soft Matter
January 2025
Department of Applied Mechanics and Biomedical Engineering, Indian Institute of Technology Madras, Chennai, 600036, Tamil Nadu, India.
Bioinspired shape-morphing soft magnetic actuators have potential applications in medicine, robotics, and engineering due to their soft body, untethered control, and infinite degrees of freedom. The shape programming of the soft magnetic actuators (consisting of soft ferromagnetic CI particles in a soft matrix) is an involved task, as it requires a moulding process severely limiting the capability to program complex shapes. The current study explores a shape programming technique that architects the particle pattern configuration in the actuator, mimicking the pattern found in the mould-programmed actuator, thereby eliminating the need for a mould and providing a greater capability of programming complex shapes.
View Article and Find Full Text PDFJ Biomed Mater Res A
January 2025
Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, USA.
In the human body, bioelectric cues are crucial for tissue stimulation and regeneration. Electrical stimulation (ES) significantly enhances the regeneration of nerves, bones, cardiovascular tissues, and wounds. However, the use of conventional devices with stimulating metal electrodes is invasive and requires external batteries.
View Article and Find Full Text PDFSci Rep
January 2025
Computational Fluid Dynamics Laboratory, School of Mechanical Engineering, VIT, Vellore, 632014, India.
Stenosis causes the narrowing of arteries due to plaque buildup, which impedes blood flow and affects flow dynamics. This work numerically analyzes flow fluctuations in stenosed arteries under realistic physiological conditions (resting and exercise) and external body acceleration. The artery is inclined at angle , and blood rheology is modeled using a generalized power-law fluid.
View Article and Find Full Text PDFJ Gynecol Obstet Hum Reprod
January 2025
Nanomedicine Imaging and Therapeutics Laboratory, INSERM EA 4662, University of Franche-Comte, Besançon, France; CHU de Besançon, Service de Gynécologie-Obstétrique, Besançon, France.
Objectives: This study aimed to describe the biometrics and elasticity of the perineal body and the anal sphincter in the ninth month of pregnancy and explore their association with the risk of perineal tears during childbirth.
Methods: In this prospective observational study, pregnant women at 36-40 weeks of gestation were included. Using transperineal 2D-mode ultrasound and shear wave elastography (SWE), we measured the biometrics and stiffness of the perineal body (PB), external anal sphincter (EAS), internal anal sphincter (IAS), and anal mucosa (AM) at rest and during Valsalva maneuvers.
Biomacromolecules
January 2025
Department of Material Engineering, Indian Institute of Science, Bangalore 560012, Karnataka, India.
Chitosan (CHT) is a known piezoelectric biomacromolecule; however, its usage is limited due to rapid degradation in an aqueous system. Herein, we prepared CHT film via a solvent casting method and cross-linked in an alkaline solution. Sodium hydroxide facilitated deprotonation, leading to increased intramolecular hydrogen bonding and mechanical properties.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!