ABSTRACT
The aim of the present study was to detect the transmission rate of ultrasonic low intensity pulsed ultrasound (LIPUS) through polytetrafluoroethylene (PTFE) membrane (Thickness: 0.01 mm) and Bio-Gide collagen membrane, and to provide the basis for the barrier membrane selection on the study of LIPUS combined with guided tissue regeneration (GTR). The ultrasonic (LIPUS, frequency 1.5 MHz, pulse width 200 micros, repetition rate 1.0 kHz) transmission coefficient of the two kinds of barrier membrane were detected respectively through setting ten groups from 10 to 100mW/cm2 every other 10 mW/cm2. We found in the study that the ultrasonic transmission coefficient through 0.01 mm PTFE membrane was 78.1% to 92.%, and the ultrasonic transmission coefficient through Bio-Gide collagen membrane was 43.9% to 55.8%. The ultrasonic transmission coefficient through PTFE membrane was obviously higher than that through Bio-Gide collagen membrane. The transmission coefficient of the same barrier membrane of the ultrasonic ion was statistically different under different powers (P < 0.05). The results showed that the ultrasonic transmittance rates through both the 0.01 mm PTFE membrane and Bio-Gide collagen membrane were relatively high. We should select barrier membranes based on different experimental needs, and exercise ultrasonic transmission coefficient experiments to ensure effective power.
Subject(s)
Biocompatible Materials , Collagen , Chemistry , Membranes, Artificial , Permeability , Polytetrafluoroethylene , Chemistry , UltrasonicsABSTRACT
OBJECTIVE To study the influence of focused ultrasound on the morphology of nasal mucosa in sheep. METHODS A model CZB ultrasound therapeutic system for rhinitis, developed and produced by Chongqing Haifu(HIFU)Technology Co.,Ltd.,Chongqing China,was used in this study. Linear scans were performed on bovine liver in vitro under different scan parameters, and the biologic focal field(BFF)was detected to evaluate if it met the requirements of designed. The nasal mucosa of inferior turbinate of sheep was exposed with the same scan parameters under the observation of nasal endoscope, and morphological changes of the nasal mucosa were observed by gross examination, light and electron microscopes. RESULTS This study revealed that the designed biological focal field in bovine liver in vitro could be obtained under the scan parameters mentioned above. Linear scan with the same condition,there was no obvious change in appearance and color of the treated nasal mucosa in the inferior turbinate of the sheep. However,3 days after treatment,there was an increased secretion in the nasal cavity,which recovered 7 days post-treatment. Light microscopic examination 3 days after exposure showed that the epithelia of the nasal mucosa was intact and there was diffused distribution of spot coagulated necroses in the subepithelia layer of treated nasal mucosa. Degeneration of vascular endothelial cells and thrombosis of blood vessels were found in the coagulated necrosis region. Besides,degeneration or necrosis of nerve cells was induced,and glandular cells werepartially or completely damaged. The structure of epithelial goblet cells and ciliated cells in the treated nasal mucosa appeared to be normal under the observation of electronic microscope. At the seventh day after treatment,signs of tissue regeneration such as hyperplasia of collagen fiber were found in the coagulated region,and the necrosis tissue began to dissolve and was absorbed at the 14th day post-treatment. CONCLUSION Under the above scan parameters,the energy of focused ultrasound could be deposited specifically at the subepithelia layer,and to ablate the targeted nasal mucous tissues which are rich in blood vessels,nerves and glands. There were no damage to the non-target area such as epithelial layer,which could maintain the normal structure and biological function of mucociliary of nasal mucosa.