Showing 3 results for Saad
Hettal Souheila, Ouahab Abdelouahab, Rahmane Saad, Benmessaoud Ouarda, Kater Aicha, Sayad Mostefa,
Volume 19, Issue 1 (March 2022)
Abstract
Copper oxide thin layers were elaborated using the sol-gel dip-coating. The thickness effect on morphological, structural, optical and electrical properties was studied. Copper chloride dihydrate was used as precursor and dissolved into methanol. The scanning electron microscopy analysis results showed that there is continuity in formation of the clusters and the nuclei with the increase of number of the dips. X-ray diffractogram showed that all the films are polycrystalline cupric oxide CuO phase with monoclinic structure with grain size in the range of 30.72 - 26.58 nm. The obtained films are clear blackin appearance, which are confirmed by the optical transmittance spectra. The optical band gap energies of the deposited films vary from 3.80 to 3.70 eV. The electrical conductivity of the films decreases from 1.90.10-2 to 7.39.10-3 (Ω.cm)-1
Farnaz Dehghani Firoozabadi, Ahmad Ramazani Saadatabadi, Azadeh Asefnejad,
Volume 19, Issue 2 (June-Biomaterials Special Issue- 2022)
Abstract
Fabrication of fully optimized tissue-engineered materials in order to simulating the natural structure, and enhancing the biological properties of damaged tissue is one of the major challenges in biomedical engineering and regeneration medicine. Although polymeric based membranes have revealed noticeable advancements in bone regeneration, their mechanical stiffens, electrical conductivity and bioactivity need to be tolerated.
Therefore, the present study is designed to generate a multifunctional biomaterial based on polylactic acid (PLA)/ polycaprolactone (PCL)/hydroxyapatite (HA) nanocomposite containing zinc oxide (ZnO) and Graphene (Gr) nanoparticles employing solvent casting combined with die cast techniques for using as absorbable joint implants in bone tissue regeneration. The physical, chemical, mechanical and biological properties of the produced nanocomposite biomaterials were analyzed in vitro. A detailed experimental evaluation between the nanocomposite coatings was carried out to shed light on the effect of ZnO and Gr nanoparticles on the properties.
It was found that the nanocomposite contained 1% ZnO and 1% graphene with a Young's modulus of 1540.5 ± 169.426MPa and the pure sample had a Young's modulus of 1194.81±215.342MPa. The rate of elongation at break of the nanostructure contained 1% graphene was 5.1±0.816%. This value was 3.8±0.944% for the pure sample. The improvement in elongation at break is due to the presence of polycaprolactone in the polymer matrix. The optimal sample with 1% zinc oxide and 1% graphene had antibacterial properties more than other samples. Also, the survival rate of fibroblasts cell in the vicinity of the optimal matrix was significantly different from other samples.
The obtained results revealed that the incorporation of the nanoparticles improved physico-chemical features and mechanical strength with enhanced biological properties and its anti-bacterial performance makes this material a promising candidate for further bone regeneration studies.
Assist. Prof. Dr. Saad Mahmood Ali,
Volume 20, Issue 4 (December 2023)
Abstract
In the present work, development models of a new artificial human soft heart and artificial heart valves using nanocomposite materials and synthetics were designed, manufactured, and tested. The fabricated mechanical artificial heart valves were examined to determine the best service life for each type. The fatigue life results were implemented by using the transient repeated and continuously applied blood pressure on each produced value to simulate diastolic and systolic that occur in the natural heart at each pulse cycle. The obtained results showed that a 3D printing of a new generation soft artificial heart for a permanent replacement was implemented as an alternative to the high-cost available temporary implant mechanical hearts, which may exceed the price by tens and hundreds of thousands of dollars, with a working life of not more than five years. The obtained fatigue safety factors for the produced artificial valves using different materials and designs were decreased with the complexity of the movement of the moving parts of the valve. The highest rates were obtained when using the valves with flat, simple movement in one direction like the single-leaflet type valve, where all the used materials are suitable for the production of this type of valve. The highest obtained safety factor was reached (15). The lowest rates were recorded when using the highly flexible and strong PSN4 nanocomposite material for fabricating the mitral tri-leaflet valve (thick. = 1.0 mm) reached 1.91. This value decreases to 0.99 when using the same type and material of valve but with a thickness equal to 0.5 mm. It can be noted here that the only suitable for the manufacture of this artificial valve type is the nanocomposite polyetherimide/ silicone rubber with nano silica (PSN4), whereas the other used materials failed because the fatigue factor values are less than 1. The service life span of this material is about 9200 x 106 cycles, which is equivalent to about 290 years, followed by SIBSTAR 103 with a default age of 209.6 x 106 cycles or 9 years.
