Duraisamy Kandasamy

Bio: Duraisamy Kandasamy is an academic researcher from University of North Carolina at Chapel Hill. The author has contributed to research in topics: Carbon-13 NMR & Sulfonate. The author has an hindex of 5, co-authored 7 publications receiving 400 citations.

Targeted Drug Delivery with Polymers and Magnetic Nanoparticles: Covalent and Noncovalent Approaches, Release Control, and Clinical Studies.

Abstract: Targeted delivery combined with controlled drug release has a pivotal role in the future of personalized medicine. This review covers the principles, advantages, and drawbacks of passive and active targeting based on various polymer and magnetic iron oxide nanoparticle carriers with drug attached by both covalent and noncovalent pathways. Attention is devoted to the tailored conjugation of targeting ligands (e.g., enzymes, antibodies, peptides) to drug carrier systems. Similarly, the approaches toward controlled drug release are discussed. Various polymer–drug conjugates based, for example, on polyethylene glycol (PEG), N-(2-hydroxypropyl)methacrylamide (HPMA), polymeric micelles, and nanoparticle carriers are explored with respect to absorption, distribution, metabolism, and excretion (ADME scheme) of administrated drug. Design and structure of superparamagnetic iron oxide nanoparticles (SPION) and condensed magnetic clusters are classified according to the mechanism of noncovalent drug loading involving...

A comparison of conformational energies calculated by several molecular mechanics methods

Abstract: Several commonly used molecular mechanics force fields have been tested for accuracy in conformational energy calculations. Differences in performance between the force fields are discussed for different classes of structures. MMFF93 and force fields based on the MM2 or MM3 functional form are found to perform significantly better than other force fields in the test, with average conformational energy errors around 0.5 kcal/mol. CFF91 also reaches this accuracy for the subset in which fully determined parameters are used, but it doubles the overall error due to use of estimated parameters. Harmonic force fields generally have average errors exceeding 1 kcal/mol. Factors influencing accuracy are identified and discussed. © 1996 by John Wiley & Son s, Inc.

Conformational Studies in the Cyclohexane Series. 1. Experimental and Computational Investigation of Methyl, Ethyl, Isopropyl, and tert-Butylcyclohexanes.

Abstract: The conformational enthalpy (ΔH°), entropy (ΔS°), and free energy (−ΔG°) of methyl- (1), ethyl- (2), and isopropylcyclohexane (3) have been reinvestigated both experimentally and computationally. A novel experimental approach to evaluation of highly biased conformational equilibria is described that obviates the need to measure large axial/equatorial isomer ratios directly in order to determine the equilibrium constant: the natural abundance 13C signal for the C(2,6) resonance in the equatorial isomer of an alkylcyclohexane may be used as an internal reference, and the ratio of this band area to that of an enriched 13C nucleus in the axial isomer gives K following correction for statistical differences and the differing 13C-content of the signals being monitored. The experimental conformational enthalpies (ΔH°), determined at 157 K in independent studies at two laboratories, were found to be (kcal/mol) 1.76 ± 0.10 (Me), 1.54 ± 0.12 (Et), and 1.40 ± 0.15 (i-Pr); the corresponding conformational entropies ...