NISCAIR Online Periodicals Repository Collection: IJEB Vol.48(10) [October 2010]

Development of transducer matrices based upon nanostructured conducting polymer for application in biosensors

Tue, 28 Sep 2010 22:58:59 GMT

Title: Development of transducer matrices based upon nanostructured conducting polymer for application in biosensors

Authors: Deepshikha; Basu, Tinku

Abstract: The nanostructured polyaniline (NSPANI) and its gold nano composite (GNP) with controlled size distribution were developed using structure directing agents (SDA). The nano structure of polyaniline were investigated by UV-Visible spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), fourrier transform spectroscopy (FTIR) , X-ray crystallography and scanning electron microscopy(SEM) etc. These characterization techniques reveal the spherical shape of polyaniline nanoparticles and size in the range of 7-50 nm depending on the type of dopant and nature of SDA. In general, these NSCP colloidal solutions are highly stable. UV-Visible spectra show mainly two peaks at 360-430 nm and at 780-870 nm. The bathochromic shift of the UV-Visible bands as compared to bulk polyaniline, reflect high DC conductivity. TEM and DLS results demonstrate the formation of nanostructure with narrow size distribution. Due to remarkable properties of, it is used as an efficient transduction matrice for the development of highly sensitive, reproducible, stable opticalcholesterol and H₂O₂biosensors having wide range of linearity and low Km values.

Page(s): 1053-1062

Co-polymeric hydrophilic nanospheres for drug delivery: Release kinetics, and cellular uptake

Tue, 28 Sep 2010 22:58:59 GMT

Title: Co-polymeric hydrophilic nanospheres for drug delivery: Release kinetics, and cellular uptake

Authors: Verma, Anita Kamra; Chanchal, A; Maitra, A

Abstract: Nanobiotechnology focuses on the biological effects and applications of nanoparticles that include nano-safety, drug encapsulation and nanotherapeutics. The present study focuses on hydrophilic nanospheres of copolymers N-isopropylacrylamide [NIPAAM] and vinyl pyrrolidone [VP], encapsulating a bioactive derivative of 5-fluorouracil-hexyl-carbamoyl fluorouracil (HCFU). The size of the nanospheres was ~58 nm and the surface charge measured was -15.4 mV. Under optimal conditions, the yield was >80%, and the drugloading was 2%. The entrapment efficiency was ~75%. Wide-angle X-ray diffraction analysis showedthat the entrapped HCFU was present in an amorphous state,which has higher water solubility compared with the crystallinestate. Slow drug release from nanospheres wasobserved in PBS and serum, with ~80% released at 37°C after72 h. The HCFU loaded polymeric nanospheres have been found to be stable in whole blood having negligible RBC toxicity. Cytotoxicity in Mia-Paca 3, pancreatic cancer cell line was done in a 24-72 h assay. Dose dependant cytotoxicity was observed when incubated with various concentrations of HCFU loaded polymeric nanospheres while HCFU per se (<1 mg) showed 90% toxicity within 24 h.

Page(s): 1043-1052

Interaction of soot derived multi-carbon nanoparticles with lung surfactants and their possible internalization inside alveolar cavity

Tue, 28 Sep 2010 22:58:59 GMT

Title: Interaction of soot derived multi-carbon nanoparticles with lung surfactants and their possible internalization inside alveolar cavity

Authors: Kumar, Pradip; Bohidar, H B

Abstract: A systematic investigation of interaction of multi-carbon nanoparticles, obtained from soot, with dipalmitoyl phosphatidylcholine (DPPC), a clinical pulmonary phospholipid surfactant, sold under trade name “Survanta”, was undertaken to establish a model for internalization of these nanoparticles inside alveolar cavity. In vitro experiments were carried out to establish the phospholipid assisted dispersion mechanism of carbon nanoclusters (size 150 nm, zeta potential -15 mV) in water. Results obtained from an array of experimental methods, like dynamic laser light scattering, electrophoresis, UV-absorption spectroscopy, surface tension studies and transmission electron microscopy, revealed that the carbon nanoparticles interacted with DPPC predominantly via hydrophobic interactions. Selective surface adsorption of DPPC molecules on nanoparticle surface was found to be strongly dependent on the concentration of the phospholipid. DPPC, a gemini surfactant, formed a rigid monolayer around the carbon nanocluster even at nanomolar concentration and provided excellent stability to the dispersion. Based on the experimental data it is proposed that the free-energy gain involved in the hydrophobic interactions will facilitate the internalization of these nanoparticles on the inner wall of the alveolar cavity.

Page(s): 1037-1042

Scope of atomic force microscopy in the advancement of nanomedicine

Tue, 28 Sep 2010 22:58:59 GMT

Title: Scope of atomic force microscopy in the advancement of nanomedicine

Authors: Ramachandran, Srinivasan; Lal, Ratnesh

Abstract: One of the most exciting fields of current research is nanomedicine, but its definition and landscape remains elusive due to its continuous expansion in all directions and thus constantly eroding its boundaries and defying definitions. This lack of conceptual framework and confusing definitions was a hurdle for policy makers to enunciate credible goals and allocate resources for the advancement of the field. In this mini review, we have provided a broad framework of nanomedicine which defines its elusive landscape, and we hope this framework will accommodate its explosive growth in the future. Also, we have highlighted the role and scope of atomic force microscopy techniques in the advancement of nanomedicine. For improving health care of all that eventually would require successful intervention at fundamental biological processes, the importance of understanding the structure-function relationship of biomolecules cannot be over emphasized. In this context, AFM and its variants play a pivotal role in contributing towards the nanomedicine knowledge-base that is required for fruitful developments in nano-diagnostics and nano-therapeutics.

Page(s): 1020-1036