scholarly journals Wireless Magnetoelasticity-Based Sensor for Monitoring the Degradation Behavior of Polylactic Acid Artificial Bone In Vitro

2019 ◽  
Vol 9 (4) ◽  
pp. 739 ◽  
Author(s):  
Kun Yu ◽  
Limin Ren ◽  
Yisong Tan ◽  
Junyao Wang
Keyword(s):  
Polylactic Acid ◽  
Output Power ◽  
Biological Tissues ◽  
Sensor Technology ◽  
Degradation Behavior ◽  
Artificial Bone ◽  
Medium Ph ◽  
Phosphate Buffered Saline

A magnetoelasticity-based (MB) sensor was employed for monitoring the degradation behavior of polylactic acid (PLA) artificial bone (PAB) in vitro, which can be used as an implant to repair bone defects. Biodegradable PLA material was coated on both sides of the MB sensor strip with a 3D printer, forming PAB. The PAB samples were submerged in an alkaline medium (pH = 12) and a neutral phosphate-buffered saline (PBS) medium (pH = 7.4). The degradation behavior of the PAB was monitored wirelessly based on changes in the output power of the MB sensor. The results indicated that the output power varied by almost 0.2 and 0.11 dbm over 15 days in the two media. The degradation behavior monitored by the MB sensor agreed with the theoretical analysis. The MB sensor provides a wireless method for monitoring the degradation behavior of PAB in vitro and requires few samples at a lower cost. Importantly, the results showed that biological tissues had almost no effect on the monitoring function of the MB sensor. Therefore, the MB sensor technology is highly attractive for fully characterizing the degradation behavior of bone implants in a larger range of physiological conditions, and will be applied to monitor the degradation behavior in vivo.

Pomegranate, its Components and Modern Deliverable Formulations as Potential Botanicals in the Prevention and Treatment of Various Cancers

2021 ◽  
Vol 18 ◽  
Author(s):  
Laila Hussein ◽  
Mostafa Gouda ◽  
Harpal S. Buttar
Keyword(s):  
Side Effects ◽  
Biological Tissues ◽  
Pomegranate Juice ◽  
In Vivo Studies ◽  
Lifestyle Modifications ◽  
Cellular Mechanisms ◽  
Double Blind ◽  
Prevention And Treatment

Abstract: Cancer is a global multifactorial disease consisting of over 200 types of cancers. It is well recognized that primary prevention is an effective way to fight cancers by using natural polyphenolic anticancer foods, vegetables and fruits, avoiding exposure to carcinogenic environment, smoking cessation, and through lifestyle modifications. The present review provides up to date information on the effects and functions of pomegranate juice and its bioactive components on the most widespread six cancer types. Pomegranate contains important polyphenolic compounds such as ellagitannins and punicalagin, with strong antioxidant ability for scavenging free radicals and producing metal-chelates in the biological tissues. The in vitro and in vivo studies suggests that antioxidant and anti-inflammation properties of pomegranate constitute have major antimutagenic and antiproliferative activities for regulating gene expression, modulating cellular mechanisms, and limiting the ability of cancers to metastasize. A limited number of clinical studies have suggested that pomegranate ingredients have the potential for the prevention and treatment of cancer, especially colorectal and prostate cancer. In cancer therapy, it remains a clinical dilemma to hit the right target without inducing side effects. The costly anticancer chemotherapies are often associated with drug resistance and serious side effects in vital organs, and noncancerous neighboring cells. It appears that the pomegranate based phytotherapies would be affordable and cost-effective for next generation non-pharmacologic anticancer remedies with lesser side effects. However, well-designed, randomized, double-blind, and multi-center studies are needed to establish the long-term safety, efficacy and dose schedules for orally deliverable pomegranate formulations.

In vivo assessment of human vaginal oxygen and carbon dioxide levels during and post menses

2005 ◽  
Vol 99 (4) ◽  
pp. 1582-1591 ◽  
Author(s):  
Donna R. Hill ◽  
Marianne E. Brunner ◽  
Deborah C. Schmitz ◽  
Catherine C. Davis ◽  
Janine A. Flood ◽  
...  
Keyword(s):  
Animal Studies ◽  
Pathogenic Bacteria ◽  
Sensor Technology ◽  
Atmospheric Conditions ◽  
Bacterial Virulence Factor ◽  
Carbon Dioxide Levels ◽  
Kinetics Of ◽  
Insertion Process

Previous in vitro and in vivo animal studies showed that O2and CO2concentrations can affect virulence of pathogenic bacteria such as Staphylococcus aureus. The objective of this work was to measure O2and CO2levels in the vaginal environment during tampon wear using newly available sensor technology. Measurements by two vaginal sensors showed a decrease in vaginal O2levels after tampon insertion. These decreases were independent of the type of tampons used and the time of measurement (mid-cycle or during menstruation). These results are not in agreement with a previous study that concluded that oxygenation of the vaginal environment during tampon use occurred via delivery of a bolus of O2during the insertion process. Our measurements of gas levels in menses showed the presence of both O2and CO2in menses. The tampons inserted into the vagina contained O2and CO2levels consistent with atmospheric conditions. Over time during tampon use, levels of O2in the tampon decreased and levels of CO2increased. Tampon absorbent capacity, menses loading, and wear time influenced the kinetics of these changes. Colonization with S. aureus had no effect on the gas profiles during menstruation. Taken collectively, these findings have important implications on the current understanding of gaseous changes in the vaginal environment during menstruation and the potential role(s) they may play in affecting bacterial virulence factor production.

Intracellular pH-temperature interactions of hepatocytes from American eels

1983 ◽  
Vol 245 (1) ◽  
pp. R32-R37
Author(s):  
P. J. Walsh ◽  
T. W. Moon
Keyword(s):  
Intracellular Ph ◽  
Acclimation Temperature ◽  
C Cells ◽  
Medium Ph ◽  
American Eel ◽  
Temperature Changes ◽  
American Eels ◽  
Temperature Interactions

The effects of acclimation temperature and acute temperature changes on the intracellular pH (pHi) of hepatocytes isolated from the American eel, Anguilla rostrata, were studied by the measurement of the distribution ratio of dimethyloxizolidinedione (DMO). Varying the concentration of DMO (10(-7) to 10(-4) M) did not affect estimates of pHi, indicating that DMO acts as an ideal pHi probe in eel hepatocytes. In vitro studies yielded values of liver cell pHi identical to those previously measured in vivo (in vitro pHi = 7.556 +/- 0.010; in vivo pHi = 7.570 +/- 0.049 at 20 degrees C); hepatocyte pHi varied inversely with acclimation temperature (5-20 degrees C) in a manner consistent with alphastat regulation (delta pH/delta T = -0.0182 +/- 0.021). During acute temperature increases (5-20 degrees C) and decreases (20-5 degrees C) hepatocytes regulated pHi to the appropriate (acclimated) value within 30-45 min posttransfer under conditions of constant medium pH (pHe). The effects of medium pH were also studied, and although patterns of pHi regulation differed between 5 and 20 degrees C cells, a pHi difference consistent with alphastat regulation was maintained between 5 and 20 degrees C cells over the pHe range 7.8-8.3.

Measurement of the Optical Properties of Muscle Tissue In Vivo

2000 ◽  
Author(s):  
P. L. Kopsombut ◽  
D. Willis ◽  
A. E. Schen ◽  
L. X. Xu ◽  
X. Xu
Keyword(s):  
Optical Properties ◽  
Transport Theory ◽  
Rapid Development ◽  
Ccd Camera ◽  
High Sensitivity ◽  
Biological Tissues ◽  
In Vivo Measurement ◽  
Living Tissues

Abstract Along with rapid development of diagnostic and therapeutic applications of lasers in medicine, optical properties of various biological tissues have been extensively studied [1]. Most of the studies were performed in vitro owing to the complexity involved in in vivo measurement. To date, it is well understood that living tissue is an absorbing and scattering heterogeneous medium because of its complex structures including blood network. The transport theory cannot be readily used due to the heterogeneity and the absence of the optical properties of living tissues [2]. In this research, we have developed a procedure for measuring the total attenuation coefficient (μ1) of the exteriorized rat 2-D spinotrapezius muscle in the wavelength ranged from 480–560 nm using the collimated light from a Nitrogen-pumped dye laser and a high-sensitivity CCD camera.

scholarly journals Docosahexaenoic Acid-Loaded Polylactic Acid Core-Shell Nanofiber Membranes for Regenerative Medicine after Spinal Cord Injury: In Vitro and In Vivo Study

2020 ◽  
Vol 21 (19) ◽  
pp. 7031
Author(s):  
Zhuo-Hao Liu ◽  
Yin-Cheng Huang ◽  
Chang-Yi Kuo ◽  
Chao-Ying Kuo ◽  
Chieh-Yu Chin ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Docosahexaenoic Acid ◽  
Neurite Outgrowth ◽  
Polylactic Acid ◽  
In Vivo Study ◽  
Core Shell ◽  
Cord Injury

Spinal cord injury (SCI) is associated with disability and a drastic decrease in quality of life for affected individuals. Previous studies support the idea that docosahexaenoic acid (DHA)-based pharmacological approach is a promising therapeutic strategy for the management of acute SCI. We postulated that a nanostructured material for controlled delivery of DHA at the lesion site may be well suited for this purpose. Toward this end, we prepare drug-loaded fibrous mats made of core-shell nanofibers by electrospinning, which contained a polylactic acid (PLA) shell for encapsulation of DHA within the core, for delivery of DHA in situ. In vitro study confirmed sustained DHA release from PLA/DHA core-shell nanofiber membrane (CSNM) for up to 36 days, which could significantly increase neurite outgrowth from primary cortical neurons in 3 days. This is supported by the upregulation of brain-derived neurotropic factor (BDNF) and neurotrophin-3 (NT-3) neural marker genes from qRT-PCR analysis. Most importantly, the sustained release of DHA could significantly increase the neurite outgrowth length from cortical neuron cells in 7 days when co-cultured with PLA/DHA CSNM, compared with cells cultured with 3 μM DHA. From in vivo study with a SCI model created in rats, implantation of PLA/DHA CSNM could significantly improve neurological functions revealed by behavior assessment in comparison with the control (no treatment) and the PLA CSNM groups. According to histological analysis, PLA/DHA CSNM also effectively reduced neuron loss and increased serotonergic nerve sprouting. Taken together, the PLA/DHA CSNM may provide a nanostructured drug delivery system for DHA and contribute to neuroprotection and promoting neuroplasticity change following SCI.

scholarly journals Preparation and evaluation in vitro and in vivo of polylactic acid microspheres containing dibucaine.

1982 ◽  
Vol 30 (10) ◽  
pp. 3719-3727 ◽  
Author(s):  
NAOKI WAKIYAMA ◽  
KAZUHIKO JUNI ◽  
MASAHIRO NAKANO
Keyword(s):  
Polylactic Acid ◽  
Preparation And Evaluation

Optimization Method of the Transcutaneous Energy Transmission System with Given Output Power

2012 ◽  
Vol 195-196 ◽  
pp. 1169-1174
Author(s):  
Liang Yu Bai ◽  
Yu Zheng ◽  
Hou Jun Tang
Keyword(s):  
Output Power ◽  
Magnetic Coupling ◽  
Optimization Method ◽  
Transmission Efficiency ◽  
Energy Transmission ◽  
Bifurcation Phenomenon ◽  
Design Variables ◽  
Transcutaneous Energy Transmission

Transcutaneous energy transmission (TET) systems are designed to deliver power from an in vitro primary power source to in vivo implantable secondary over relatively large air gaps via magnetic coupling. This paper proposes an optimization method with given output power to meet different practical application. The transmission efficiency is the objective function; primary and secondary coils are design variables; constraints are based on bifurcation phenomenon and components peak over-voltage and peak withstand current. We have used MATLAB/ SIMULINK to verify the analytical results.

scholarly journals Drug Release Kinetics of Electrospun PHB Meshes

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1924 ◽  
Author(s):  
Vojtech Kundrat ◽  
Nicole Cernekova ◽  
Adriana Kovalcik ◽  
Vojtech Enev ◽  
Ivana Marova
Keyword(s):  
Release Kinetics ◽  
Entrapment Efficiency ◽  
Toxic Substances ◽  
Antimicrobial Efficiency ◽  
Vis Spectroscopy ◽  
Model Drug ◽  
Phosphate Buffered Saline ◽  
Kinetics Of

Microbial poly(3-hydroxybutyrate) (PHB) has several advantages including its biocompatibility and ability to degrade in vivo and in vitro without toxic substances. This paper investigates the feasibility of electrospun PHB meshes serving as drug delivery systems. The morphology of the electrospun samples was modified by varying the concentration of PHB in solution and the solvent composition. Scanning electron microscopy of the electrospun PHB scaffolds revealed the formation of different morphologies including porous, filamentous/beaded and fiber structures. Levofloxacin was used as the model drug for incorporation into PHB electrospun meshes. The entrapment efficiency was found to be dependent on the viscosity of the PHB solution used for electrospinning and ranged from 14.4–81.8%. The incorporation of levofloxacin in electrospun meshes was confirmed by Fourier-transform infrared spectroscopy and UV-VIS spectroscopy. The effect of the morphology of the electrospun meshes on the levofloxacin release profile was screened in vitro in phosphate-buffered saline solution. Depending upon the morphology, the electrospun meshes released about 14–20% of levofloxacin during the first 24 h. The percentage of drug released after 13 days increased up to 32.4% and was similar for all tested morphologies. The antimicrobial efficiency of all tested samples independent of the morphology, was confirmed by agar diffusion testing.

Contribution of LFA-1 and Mac-1 to CD18-dependent neutrophil emigration in a neonatal rabbit model

1996 ◽  
Vol 80 (6) ◽  
pp. 1984-1992 ◽  
Author(s):  
J. M. Graf ◽  
C. W. Smith ◽  
M. M. Mariscalco
Keyword(s):  
Monoclonal Antibody ◽  
Polymorphonuclear Leukocytes ◽  
Rabbit Model ◽  
Transendothelial Migration ◽  
Peritoneal Exudate ◽  
Adult Rabbit ◽  
Primary Mechanism ◽  
Phosphate Buffered Saline

Human neonatal polymorphonuclear leukocytes (PMNs) exhibit decreased mobility, adherence, and transendothelial migration in vitro compared with adult PMNs. These deficits, in part, are due to functional and quantitative defects in neonatal Mac-1 (CD11b/CD18), whereas LFA-1 (CD11a/CD18) function is similar to that found in adults (D.C.Anderson, O.Abbassi, T.K.Kishimoto, J.M.Koenig, L.V.McIntire, and C.W.Smith, J.Immunol. 146: 3372-3379, 1991; C. W. Smith, T. K. Kishimoto, O. Abbassi, B.J.Hughes, R.Rothlein, L.V.McIntire, E.Butcher, and D.C. Anderson, J. Clin. Invest. 87: 609-618, 1991). We tested the hypothesis that the primary mechanism for the neonatal PMN CD18-dependent emigration in vivo is due to LFA-1. Neutrophils from 1-day-old rabbit pups had 32 and 60% of adult rabbit levels of CD11a and CD11b, respectively. Rabbit pups or adult rabbits received the monoclonal antibody (MAb) R7.1 (anti-CD11a) or R15.7 (anti-CD18) or the vehicle phosphate-buffered saline (PBS) before the instillation of intraperitoneal thioglycollate. Six hours later peritoneal exudate was collected. The administration of MAbs R7.1 and R15.7 in adult animals resulted in 60 and 83% inhibition of leukocyte emigration, respectively, compared with PBS-treated animals (P < 0.01). In neonatal animals, R7.1 and R15.7 inhibited leukocyte peritoneal accumulation to the same extent (50 and 60%, respectively) compared with PBS-treated animals (P < 0.01). Adult animals were also treated with the anti-CD11b MAb 198. MAb 198 decreased emigration by 25%, although this was not significant compared with PBS-treated animals. We conclude that although neonatal animals have significantly less neutrophil CD11a, the diminished levels did not contribute to a reduced ability to emigrate to the peritoneum and, like adult animals, neonatal animals primarily utilize LFA-1 for accumulation in this model. The contribution of Mac-1 to neonatal leukocyte emigration remains uncertain.

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