Bright Singh, I S; Rosamma, Philip; Anas, A(Blackwell Publishing, June 1, 2008)
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Abstract:
Chitosan has beenwidely accepted as awall material
for preparing microcapsules of various purposes in
human medicine. The possibility of using chitosan
as a wall material for microencapsulating nutrients
and drugs for aquaculture purposes, speci¢cally to
Macrobrachium rosenbergii larvae was evaluated in
this study. Two types of chitosan-coated microcapsules
were prepared using either acetone (MEC-A) or
NaOH (MEC-N) as the cross-linking agents. They
were compared with a microbound diet relative to
total leaching of nutrients and free amino acids
(FAA). Among the microcapsules, MEC-N showed
the lowest level of total leaching of nutrients (23.3%)
during 5 h of immersion in seawater and released
65% FAA after 60min. During laboratory trials,75%
larvae had accepted the MEC-N capsule. The results
of the study suggest that chitosan can be used as a
wall material for preparing microcapsules to deliver
drugs and nutrients to M. rosenbergii larvae.
Nisha, V S; Rani, Joseph(Dept. of Polymer Science and Rubber Technology, May , 2006)
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Abstract:
The present work is to impart radiopacity in various natural polymers like chitosan, natural rubber and derivatives of chitosan and to characterize it. This thesis collated the radiopaque properties of these radiopaque polymers and various technological applications in the medical field. The applications of radiopaque polymers leads to an exploitation of radiopaque properties like X-ray visibility, optical density, effective atomic number, attenuation coefficient of biopolymers like chitosan, chitosan formate, chitosan acetate, carboxy methyl chitosan and natural rubber. The radiopaqe properties of these materials highly depend upon the size, shape, amount of radiopacifier and crystallinity of the radiopaque material. Radiopaque chitosan microspheres were prepared by cross linking with glutaraldehyde followed by the encapsulation of barium sulpahte. The effect of different emulsion systems on the morphology of chitosan microspheres were studied. The study concentrates radiopaque natural rubber for shielding applications. It reveals that to improve the particle size, morphology and crystalline phase of the zinc oxide particles, a novel method for the preparation of zinc oxide is adopted. A detailed radiopacity study was done in natural rubber containing 100phr precipitated zinc oxide prepared from different zinc salts. One of the significant findings of this investigation is that NR vulcanizates containing precipitated zinc oxide (from zinc acetate) shows higher attenuation coefficient. These interesting findings reveal the applications of these natural radiopaque systems in various fields like surgical tools, medical tubings, catheters, radiation shielding,etc.