scholarly journals Naturally Derived a-Tricalcium Phosphate Based Porous Composite Bead Production

2019 ◽  
Vol 16 (3) ◽  
pp. 240-251
Author(s):  
Gulsum AYDIN ◽  
Kenan YILDIRIM ◽  
Ayse KALEMTAS

In this study, a simple, innovative approach is applied to produce porous a-TCP-CeO2-Al2O3 composite beads via using bovine bone-derived hydroxyapatite, cerium oxide, and alumina ceramics. Bovine-bone derived hydroxyapatite was obtained via calcination of bones at 950°C for 3 hours. Hydroxyapatite is a thermally unstable biomaterial at high temperatures, and depending on its stoichiometry decomposes at 800-1200°C. Sodium alginate was successfully used as an in situ gelling templates for the production of the ceramic beads and starch, an environmentally friendly and economic pore-forming agent, is used to achieve interconnected, highly open porosity containing composite beads. Sintering of the ceramic−starch−alginate green composite beads at 1200°C for 1 hour resulted in the decomposition of the hydroxyapatite phase and formation of a-TCP. XRD analysis revealed that a-TCP-CeO2-Al2O3 composite beads were achieved. XRD analysis confirmed the formation of a-TCP phase in all composite compositions. SEM investigations of the produced composite beads revealed that bimodal pore size distribution, fine and coarse, was achieved.

2013 ◽  
Vol 743-744 ◽  
pp. 486-490
Author(s):  
Ming Mei Xu ◽  
Wang Xiao ◽  
Yong Zhu Cui ◽  
Wei Shao ◽  
Yan Ling Sui ◽  
...  

nanosize hydroxyapatite/polyacrylonitrile composite bead was prepared via in-situ synthesis method. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), particle size measurement and X-ray diffraction (XRD) were used to characterize the HAp/PAN composite bead. XRD curve indicates low crystallinity of HAp. Particle size and SEM analysis demonstrates that decreased partical size of synthesized HAp as well as good distribution with the addition of PAN is found. The HAp is well-distributed and the combination between HAp and PAN is well. FTIR showed that there was no shift of characteristic peaks of synthesized HAp in PAN, which proves the physical interaction between PAN and HAp. The approximate HAp content of 28.6% calculated from thermal analysis curves means high conversion ratio of HAp. The adsorption amount of cadmium ions onto composite beads is lower than HAp particles.


Author(s):  
Kranti Singh ◽  
Surajpal Verma ◽  
Shyam Prasad ◽  
Indu Bala

Ciprofloxacin hydrochloride loaded Eudragit RS100 nanoparticles were prepared by using w/o/w emulsification (multiple emulsification) solvent evaporation followed by drying of nanoparticles at 50°C. The nanoparticles were further incorporated into the pH-triggered in situ gel forming system which was prepared using Carbopol 940 in combination with HPMC as viscosifying agent. The developed nanoparticles was evaluated for particle size, zeta potential value and loading efficiency; nanoparticle incorporated in situ gelling system was evaluated for pH, clarity, gelling strength, rheological studies, in-vitro release studies and ex-vivo precorneal permeation studies. The nanopaticle showed the mean particle size varying between 263.5nm - 325.9 nm with the mean zeta potential value of -5.91 mV to -8.13 mV and drug loading capacity varied individually between 72.50% to 98.70% w/w. The formulation was clear with no suspended particles, showed good gelling properties. The gelling was quick and remained for longer time period. The developed formulation was therapeutically efficacious, stable and non-irritant. It provided the sustained release of drug over a period of 8-10 hours.


2021 ◽  
Author(s):  
Ruixue Zhang ◽  
Wanying Zhao ◽  
Zhenzhen Liu ◽  
Shanghai Wei ◽  
Yigang Yan ◽  
...  

In situ formed amorphous LiBH4·1/2NH3 on the surface of Al2O3 nanoparticles results in an enhanced ion conductivity of 1.1 × 10−3 S cm−1 at room temperature.


Vacuum ◽  
2012 ◽  
Vol 86 (6) ◽  
pp. 785-788 ◽  
Author(s):  
Jan Riha ◽  
Pavol Sutta ◽  
Andrej Vincze ◽  
Rostislav Medlin

Spine ◽  
2008 ◽  
Vol 33 (7) ◽  
pp. 748-754 ◽  
Author(s):  
Mohammed F. Shamji ◽  
Lyman Whitlatch ◽  
Allan H. Friedman ◽  
William J. Richardson ◽  
Ashutosh Chilkoti ◽  
...  

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