Biomedical Engineering Reference
In-Depth Information
whereas free drugs were cleared within 12-24h from the plasma. Five oral
doses were sui cient for completely bacterial clearance whereas free drugs
took 46 doses to get the same results [20]. Injectable PLGA (poly lactic-
co-glycolic acid) nanoparticles were also administered subcutaneously in a
murine model. A single subcutaneous dose of PLGA nanoparticles main-
tains drug levels in plasma, lungs, and spleen for <1 month and bacterial
count remain almost undetectable in these organs [21].
Niosomes are similar to liposomes and are mainly composed of non-
ionic surfactant with or without incorporation of lipids. Recently nio-
somes were prepared by reverse phase evaporation method and given
a charge with a charge-inducing agent, dicetyl phosphate. Drug entrap-
ment ei ciency was determined by spectrophotometer
. In vitro
drug
release and cellular uptake studies was also carried out on macrophage
J774A. As a result the cellular uptake of drug loaded by macrophage cells
was as high as 61.8% a level which is capable for ef ective treatment of
tuberculosis [22].
Micelles are sub microscopic aggregates (20-80 nm) of surfactant mol-
ecules resulting in liquid colloid [8]. PLA (poly lactic acid) modii ed chi-
tosan oligomer micelles release 35% drug release within 10h followed by
more sustained drug release till 5 days suggesting the role of micelles as
drug carrier with reduced side ef ects. Alginate nanoparticles are also used
as drug delivery for tuberculosis treatment. Zahroor
et al
used ionotropic
gelation method for preparing alginate nanoparticles (235nm) of anti-TB
drug. Oral administration of drug to mice resulted in detection of level
free drugs in tissues till next day. Whereas in plasma alginate nanoparticles
were detected up to 7 days for ETB (ethambutol), 9 days for RIF, 11 days for
INH and 15 days for PYZ in tissues [24]. Gold Nanoparticles, Mesoporous
Silica Nanoparticles, Quantum Dots are also employed for detection, imag-
ing and treatment of various diseases.
Gold nanoparticles preparation involves the chemical reduction of gold
salts in aqueous, organic, or mixed solvent system. Under these condi-
tions gold surface are extremely reactive as a result aggregation occurs. To
reduce aggregation, gold nanoparticles were reduced in the presence of a
stabilizer which binds to the surface and remove aggregation via cross link-
ing and charge properties. Gold nanoparticles are also used for biological
imaging and sensing. A simple gold nanoparticle probe assay was done to
detect
Mycobacterium tuberculosis
and its complex in clinical specimen.
An assay using gold nanoparticles derivatized with thiol modii ed oligo-
nucleotides was carried out. h e gold nanoparticle probes GP-1/GP-2 for
IS6110 and GP-3/GP-4 for Rv3618 were designed to hybridize with target
DNAs of MTB and MTBC strains. h en the ei ciency of gold nanoparticle
