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Development and Evaluation of Novel Biodegradable Docetaxel Loaded Microspheres of Poly (D, L-Lactide-Co-Glycolic acid) and Poly (ε-Caprolactone)for Controlled Drug Delivery.
No full textThe main objective of this study was to develop a
polymeric drug delivery system for controlled
release of docetaxel. This system was capable of
improving the therapeutic index of drug and devoid
of adverse effect of polysorbate 80 in Taxotere.
Polycapro-ε lactone (PCL) and poly (lactic –coglycolic
acid) (PLGA) microspheres were prepared by
solvent evaporation method. Solvent evaporation
method was used for the successful entrapment of
drug with in polymer particles. The influence of
different processing parameters on the size and
surface morphology of microspheres was evaluated.
Effect of docetaxel concentration on encapsulation
efficiency and released pattern was also studied. We
achieved good encapsulation efficiency i.e 92.19 ±
0.23, 86.38 ± 0.02 for F1 ( 1:2 Drug: PCL) and F4 ( 1:2
drug : PLGA) formulations respectively. Cumulative
% drug released was found 56.95± 0.024 for PCL (F1)
and 80.54± 0.035 for PLGA (F4) formulation after 30
days incubation in PBS buffer (pH 7.4). Both the
formulation followed higuchi model and the release
mechanism was found non fickian on the basis of
diffusion exponent value of 0.86 and 0.83 for F1 and
F4 formulation respectively. The formulations were
found stable and very effective for controlled drug
delivery
A Simple FBG Sensor for Strain- Temperature Discrimination
No full textA simple sensor using half the length of a 3-cm
fiber Bragg grating embedded on a cantilever is proposed for the simultaneous measurement and discrimination of strain and
temperature. The response of the sensor is linear from 30 to
200C, and its strain and temperature sensitivities are found to be 3.38 pm/lm 19.05 pm/C, respectivel
Recovery of Pure ZnO Nanoparticles from Spent Zn-Mno2 Alkaline Batteries
No full textThe recovery of pure ZnO (zinc oxide) nanoparticles from spent Zn-Mn dry alkaline batteries is reported. Spent batteries were dismantled to separate the contained valuable metals of the cell electrodes in the form of black powder. Treatment of this black powder with 5 mol L(-1) HCl produced leach liquor, primarily containing 2.90 g L(-1) Zn and 2.02 g L(-1) Mn. Selective and quantitative liquid-liquid extraction of Zn(II) was then carried out in three counter current steps by using Cyanex 923 (0.10 mol L(-1) in n-hexane). Zn(II) distributed in the organic phase as complex ZnCl(2)·2R (R = Cyanex 923 molecule). The metal loaded organic phase was subjected to combust at 600 °C to yield pure ZnO nanoparticles (40-50 nm). Important characteristics of the synthesized nanoparticles were investigated by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD), and atomic force microscopy (AFM)
Fiber grating sensors in medicine: Current and emerging applications
No full textFiber grating sensors hold immense potential for biomedical applications due to their inherent properties like small size, biocompatibility, non-toxicity, chemical inertness and electromagnetically inert nature. Grating based sensors are well known technology for structural health monitoring (SHM) in the arena of civil and aerospace; however investigations for their use in the field of medicine are fairly recent and they have not been yet commercialized for the same. As these sensors detect strain, temperature, pressure, vibration, curvature and refractive index of the surrounding material even in high magnetic and electric field environments, they can serve diagnostic purposes in diverse areas of healthcare e.g. biomechanics, cardiology, gynecology, very low temperature monitoring and immunosensing to name a few. Most importantly, they can be used efficiently for thermal and pressure mapping even during MRI procedure where conventional sensors may fail. The paper is a review of various application areas of fiber grating based devices, the status of precedent and ongoing research around the world, and discussion on the issues hampering their rapid growth in the field
Etched multimode microfiber knot-type loop interferometer refractive index sensor
No full textWe propose a novel refractive index sensor based on multimode microfiber knot-type loop (NL) interferometer. The middle portion (similar to 5 cm) of a 15 cm long multimode fiber is etched in 48% hydrofluoric acid to reduce its diameter to similar to 12 mu m. A NL of diameter < 1 mm is made from the etched fiber. The ends of etched fiber are spliced with single-mode fibers for launching and detecting light from the NL interferometer. The NL introduces path differences to produce interferometric spectra with free spectral range similar to 16 nm. The spectrum shifts as the surrounding refractive index of the loop is changed by adding chemicals. We observe the highest sensitivity of the NL interferometer similar to 172 nm/RIU (refractive index unit) at a refractive index value 1.370 as obtained experimentally using commonly available chemicals. The design could be used as simple, low cost, and highly sensitive biological and chemical senso
Transportation of drug-gold nanocomposites by actinomyosin motor system
No full textNanotechnology is playing an important
role in drug delivery to overcome limitations of
conventional drug delivery systems in terms of solubility,
in vivo stability, pharmacokinetics, and biodistribution.
The controlled transportation of drug into
the cell and within the cell is a major challenge to be
addressed. Cellular molecular motors have been
exploited for their cargo carrying capacity for various
applications including engineering and health care.
Combination of nanotechnology and biomolecular
motors can address some of the challenges in drug
delivery. In the present study, transportation of drug
nanocomposites has been demonstrated. Nanocomposites
of 6-mercaptopurine and levodopa drugs
(cancer and Parkinson’s disease, respectively) were
prepared with gold nanoparticles (GNPs) by covalent
attachment and these nanocomposites were attached to
actin filaments. These nanocomposites were in-turn
transported by actin filaments on myosin tracks.
Characterization of drug nanocomposites formation
was done by UV–Vis spectroscopy, field emission
scanning electron microscopy, transmission electron
microscopy, and confocal microscopy. GNP composites
of 6-mercaptopurine and levodopa were formed by
sulfide and amide bond formation, respectively. Average
velocity of actin filament attached to nanocomposites
was found to be 3.17 and 3.89 lm/s for levodopa and 6-mercaptopurine, respectively, as compared to actin filaments with velocity of 4.0–6.0 lm/s. Three concepts have been proposed for the study of drug transportation into the cell based on polycationic complex formation, interaction of actin with cellular myosin and Biomolecular Adaptor for Retrograde Transport (BART) technology. The aspects of this study heads toward the development of an approach to utilize molecular motors for nanoscale transportation endogenously
Dielectric behaviour of emeraldine base polymer–ZnO nanocomposite film in the low to medium frequency
No full textEmeraldine base (EB) polymer–ZnO nanoparticles composite films has been synthesized by solution casting technique on ITO-coated glass substrate and characterized by XRD, FTIR and TEM for their structure and morphology. Dielectric behaviour of these composite films has been investigated in
the very low frequency region to medium frequency region (1 kHz–1 MHz). The dielectric constant of the composite with 30% nanoparticles is almost onetenth of the pure EB. The dielectric value becomes constant in the frequency region greater than 400 kHz. The change in dielectric behaviour of the composite is explained on the basis of multilayered
interface formed between the ZnO nanoparticles and
emeraldine chains. Nanoparticles have high energy
surface which is responsible for the decrease of free
volume for the orientation of polymer chains consequently
decrease in dielectric constant of the composite.
TEM images shows about 10 nm ZnO particles embedded in the emeraldine matrix. From the XRD data it has been observed that the lattice parameters of ZnO have been modified due to the alignment of polymer chains along the basal planes of
the nanoparticles. The shift of N=Q=N and N–B–N
vibration bands to higher wave number in IR indicates that interaction between emeraldine chain and nanoparticles which provides stability to emeraldine matrix
Light Interaction of a Nanoparticle Embedded Tissue towards a Novel Hyperthermia Treatment
No full textLight interaction of nanoparticles embedded in a tissue decides the amount of thermal energy absorbed, which is key to plasmonic photothermal therapy, a recent concept for treatment of cancer. The light interaction depends on the shape‐size‐type of nanoparticles, type of tissue and the wavelength of light used. A numerical model is developed to capture light interaction of a nanoparticle embedded tissue and subsequently estimate spatial heating of the tissue
Fiber Bragg Granting Sensor for Detection of Nitrate Concentration in Water
No full textThe concentrations of chemical species in drinking water are of great interest. We demonstrated etched fiber Bragg grating (FBG) as a concentration sensor for nitrate by analyzing the Bragg wavelength shift with concentration of chemical solution. The FBG is fabricated by phase mask
technique on single mode Ge-B co-doped photosensitive fiber. Sensitivity of FBGs to the surrounding
solution concentration can be enhanced by reducing diameter of the cladding with 40 % HF solution.
The maximum sensitivity achieved is 1.322 10-3 nm/ppm. The overall shift of Bragg wavelength is of
the order of 6.611 10-2 nm for 10 to 50 ppm concentration. Copyright © 2011 IFSA
Influence on Color Attributes with Time due to Variations in Temperature Conditions
No full textThe effects of time and temperature over the color of freshly brewed Indian tea liquor using spectrophotometer were evaluated. The study suggests that after brewing, the tea samples undergo a color change which was measured in CIE L*a*b* color model. To find out the temperature effects, the experiment was done under two conditions i.e. normal cooling and imposed cooling of the sample to room temperature immediately after brewing. Change in the color was found less prominent in the latter case and it is concluded that the color changes rapidly after brewing and can pose difficulty in quality assessment of tea samples by tea tasters during visual inspection, if time and temperature are not taken into accoun