Donald A. Tomalia

Bio: Donald A. Tomalia is an academic researcher from University of Pennsylvania. The author has contributed to research in topics: Dendrimer & Poly(amidoamine). The author has an hindex of 81, co-authored 266 publications receiving 32422 citations. Previous affiliations of Donald A. Tomalia include Columbia University & Michigan Molecular Institute.

A new class of polymers: Starburst-dendritic macromolecules

Abstract: This paper describes the first synthesis of a new class of topological macromolecules which we refer to as “starburst polymers.” The fundamental building blocks to this new polymer class are referred to as “dendrimers.” These dendrimers differ from classical monomers/oligomers by their extraordinary symmetry, high branching and maximized (telechelic) terminal functionality density. The dendrimers possess “reactive end groups” which allow (a) controlled moelcular weight building (monodispersity), (b) controlled branching (topology), and (c) versatility in design and modification of the terminal end groups. Dendrimer synthesis is accomplished by a variety of strategies involving “time sequenced propagation” techniques. The resulting dendrimers grow in a geometrically progressive fashion as shown: Chemically bridging these dendrimers leads to the new class of macromolecules—”starburst polymers” (e.g., (A)n, (B)n, or (C)n).

Starburst Dendrimers: Molecular-Level Control of Size, Shape, Surface Chemistry, Topology, and Flexibility from Atoms to Macroscopic Matter

Abstract: Starburst dendrimers are three-dimensional, highly ordered oligomeric and polymeric compounds formed by reiterative reaction sequences starting from smaller molecules—“initiator cores” such as ammonia or pentaerythritol. Protecting group strategies are crucial in these syntheses, which proceed via discrete “Aufbau” stages referred to as generations. Critical molecular design parameters (CMDPs) such as size, shape, and surface chemistry may be controlled by the reactions and synthetic building blocks used. Starburst dendrimers can mimic certain properties of micelles and liposomes and even those of biomolecules and the still more complicated, but highly organized, building blocks of biological systems. Numerous applications of these compounds are conceivable, particularly in mimicking the functions of large biomolecules as drug carriers and immunogens. This new branch of “supramolecular chemistry” should spark new developments in both organic and macromolecular chemistry.

Dendrimers and other dendritic polymers

Abstract: Contibutors. Series Preface. A Brief Historical Perspective (D.A. Tomalia naad J.M.J. Frecht) B>I Introduction and Progress in the Control of Macromolecular Architecture Introduction to the Dendritic State (D.A. Tomalia and J.M. Frechet) Structure Control of Linear Macromolecules (C.J. Hawker) Progress in the Branched Architectural State (J. Roovers) Developments in the Accelerated Convergent Synthesis of Dendrimers (A.W. Freeman and J.M.J. Frechet) Formation, Structure and Properties of the Crosslinked State Relative to Precursor Architecture (K. Dusek and M. Duskova--Smrckova) Regioselectively--Crosslinked Nanostructures (C.G. Clark Jr and K. L. Wooley) Hybridization of Architectural States: Dendritic--linear Copolymer Hybrids (P.R.L. Malenfant and J.M.J. Frechet) Statistically Branched Dendritic Polymers (E. Malmstrom and A. Hult) Semi--Controlled Dendritic Structure Synthesis (R.A. Kee et al) II Characterization of Dendritic Polymers Gel Electrophoretic Characterization of Dendritic Polymers (C. Zhang and D.A. Tomalia) Characterization of Dendritically Branched Polymers by Small Angle Neutron Scattering (SANS), Small Angle X--ray Scattering (SAXS), and Transmission Electron Microscopy (TEM) (B.J. Bauer and E.J. Amis) Atomic Force Microscopy for the Characterization of Dendritic Polymers and Assemblies (J. Li and D.A. Tomalia) Characterization of Dendrimer Structures by Spectroscopic Techniques (N.J. Turro et al) Rheology and Solution Properties of Dendrimers (P. Dvornic and S. Uppuluri) III Properties and Applications of Dendritic Polymers Dendritic and Hyperbranched Glycoconjugates as Biomedical Anti--Adhesion Agents (R. Roy) Some Unique Features of Dendrimers based upon Self--assembly and Host--Guest Properties (J. Weener et al) Dendritic Polymers: Optical and Photchemical Properties (D.L. Jiang and T Aida) Bioapplications of PAMAM Dendrimers (J.D. Eichman et al) Dendrimer--Based Biological Reagents: Preparation And Applications in Diagnostics (P. Singh) Dendritic Polymer Applications: Catalysts (A.W. Kleij et al ) Optical Effects Manifested by PAMAM Dendrimer Metal Nano--Composites (T. Goodson III) Dendrimers in Nanobiological Devices (S.C. Lee) Antibodies to PAMAM dendrimers: Reagents for immune detection, patterning and assembly of Dendrimers (S.C. Lee et al) IV Laboratory Preparation of Dendrimers and Conclusion Preparation of a Frechet--typea Polyether Dendrons and Aliphatic Polyester Dendrimers by Convergent Growth: an experimental primer (J.M.J. Frechet et al) Laboratory Synthesis of Poly(amidoamine) (PAMAM) Dendrimers (R. Esfand and D.A. Tomalia) Synthesis and Characterization of Poly(Propylene imine) Dendrimers (M.H.P. van Genderen et al) Laboratory Synthesis and Characterization of Megamers: Core--shell Tecto(dendrimers) (D.A. Tomalia) Conclusion/Outlook -- Toward Higher Macromolecular Complexity in the Twenty--first Century (D.A. Tomalia and J.M.J. Frechet) Index

Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology.

Abstract: Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

Cancer nanotechnology: opportunities and challenges.

Abstract: Nanotechnology is a multidisciplinary field, which covers a vast and diverse array of devices derived from engineering, biology, physics and chemistry. These devices include nanovectors for the targeted delivery of anticancer drugs and imaging contrast agents. Nanowires and nanocantilever arrays are among the leading approaches under development for the early detection of precancerous and malignant lesions from biological fluids. These and other nanodevices can provide essential breakthroughs in the fight against cancer.

Gadolinium(III) Chelates as MRI Contrast Agents: Structure, Dynamics, and Applications

Abstract: A. Water Exchange 2326 B. Proton Exchange 2327 C. Electronic Relaxation 2327 D. Relaxivity 2331 E. Outerand Second-Sphere Relaxivity 2334 F. Methods of Improving Relaxivity 2336 V. Macromolecular Conjugates 2336 A. Introduction 2336 B. General Conjugation Methods 2336 C. Synthetic Linear Polymers 2336 D. Synthetic Dendrimer-Based Agents 2338 E. Naturally Occurring Polymers (Proteins, Polysaccharides, and Nucleic Acids) 2339

Long-Circulating and Target-Specific Nanoparticles: Theory to Practice

Abstract: The rapid recognition of intravenously injected colloidal carriers, such as liposomes and polymeric nanospheres from the blood by Kupffer cells, has initiated a surge of development for "Kupffer cell-evading" or long-circulating particles. Such carriers have applications in vascular drug delivery and release, site-specific targeting (passive as well as active targeting), as well as transfusion medicine. In this article we have critically reviewed and assessed the rational approaches in the design as well as the biological performance of such constructs. For engineering and design of long-circulating carriers, we have taken a lead from nature. Here, we have explored the surface mechanisms, which affords red blood cells long-circulatory lives and the ability of specific microorganisms to evade macrophage recognition. Our analysis is then centered where such strategies have been translated and fabricated to design a wide range of particulate carriers (e.g., nanospheres, liposomes, micelles, oil-in-water emulsions) with prolonged circulation and/or target specificity. With regard to the targeting issues, attention is particularly focused on the importance of physiological barriers and disease states.