Nicholas A. Peppas

Bio: Nicholas A. Peppas is an academic researcher from University of Texas at Austin. The author has contributed to research in topics: Self-healing hydrogels & Drug delivery. The author has an hindex of 141, co-authored 825 publications receiving 90533 citations. Previous affiliations of Nicholas A. Peppas include National Technical University & University of Texas System.

Transport and delivery of interferon-α through epithelial tight junctions via pH-responsive poly(methacrylic acid-grafted-ethylene glycol) nanoparticles.

Abstract: Whereas significant advancements have been made in our fundamental understanding of cancer, they have not yet translated into effective clinical cancer treatments. One of the areas that has the potential to improve the efficacy of cancer therapies is the development of novel drug delivery technologies. In particular, the design of pH-sensitive polymeric complexation hydrogels may allow for targeted oral delivery of a wide variety of chemotherapeutic drugs and proteins. In this work, poly(methacrylic acid-grafted-ethylene glycol) hydrogel nanoparticles were synthesised, characterised, and studied as matrix-type, diffusion-controlled, pH-responsive carriers to enable the oral delivery of the chemotherapeutic agent interferon alpha (IFN-α). The biophysical mechanisms controlling the transport of IFN-α were investigated using a Caco-2/HT29-MTX co-culture as a gastrointestinal (GI) tract model. The synthesised nanoparticles exhibited pH-responsive swelling behaviour and allowed the permeation of IFN-α through the tight junctions of the developed cellular GI epithelium model. These studies demonstrate the capabilities of these particles to contribute to the improved oral delivery of protein chemotherapeutics.

Molecularly Imprinted Intelligent Scaffolds for Tissue Engineering Applications.

Abstract: The development of molecularly imprinted polymers (MIPs) using biocompatible production methods enables the possibility to further exploit this technology for biomedical applications. Tissue engine...

9.20 – Hydrogels

Abstract: Hydrogels are three-dimensional network structures able to imbibe large amounts of water. Hydrogels do not typically dissolve due to chemical or physical cross-links and/or chain entanglements. They exist naturally in the form of polymer networks such as collagen or gelatin, or can be made synthetically. Environmentally sensitive hydrogels can serve a wide variety of applications because of their ability to respond to environmental changes, typically by exhibiting changes in volume. Traditional stimuli that elicit hydrogel response are pH, temperature, and ionic strength. Analytes and biomarkers including glucose, proteins, and DNA also elicit hydrogel responses. Because of such a wide variety of response triggers, hydrogels can be incorporated into sensors or actuators, or can be utilized in controlled drug delivery systems, biosensors, tissue engineering scaffolds, artificial organs, wound healing bandages, physiological membranes, contact lenses, and microfluidic valves.

Modeling of water transport in and release from glucose-sensitive swelling-controlled release systems based on poly(diethylaminoethyl methacrylate-g-ethylene glycol)

Abstract: The glucose-sensitive behavior of glucose-sensitive, poly(diethylaminoethyl methacrylate-g-ethylene glycol) hydrogels was modeled and analyzed in the case of exposure to glucose solutions. Gel microparticles were prepared with molar ratios of 10:1 diethylaminoethyl methacrylate to poly(ethylene glycol) of molecular weights 200, 400, and 1000, using tetra(ethylene glycol) dimethacrylate as a cross-linking agent. Glucose oxidase and catalase was immobilized in the matrix during polymerization. The equilibrium and dynamic swelling properties of these hydrogels were investigated. The pH-dependent equilibrium swelling characteristics showed a sharp transition between the swollen state and the collapsed state at a pH of 7.0. Microparticles showed rapid swelling and collapse under the influence of pulsatile pH changes. The glucose-sensitive behavior of the gels due to glucose oxidase was also studied. Diffusion and relaxation models were used to predict swelling of single microparticles under different pH and gl...

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

The Design and Analysis of Experiments

Abstract: THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

Harrison's Principles of Internal Medicine

Abstract: The 11th edition of Harrison's Principles of Internal Medicine welcomes Anthony Fauci to its editorial staff, in addition to more than 85 new contributors. While the organization of the book is similar to previous editions, major emphasis has been placed on disorders that affect multiple organ systems. Important advances in genetics, immunology, and oncology are emphasized. Many chapters of the book have been rewritten and describe major advances in internal medicine. Subjects that received only a paragraph or two of attention in previous editions are now covered in entire chapters. Among the chapters that have been extensively revised are the chapters on infections in the compromised host, on skin rashes in infections, on many of the viral infections, including cytomegalovirus and Epstein-Barr virus, on sexually transmitted diseases, on diabetes mellitus, on disorders of bone and mineral metabolism, and on lymphadenopathy and splenomegaly. The major revisions in these chapters and many

Understanding biophysicochemical interactions at the nano–bio interface

Abstract: Rapid growth in nanotechnology is increasing the likelihood of engineered nanomaterials coming into contact with humans and the environment. Nanoparticles interacting with proteins, membranes, cells, DNA and organelles establish a series of nanoparticle/biological interfaces that depend on colloidal forces as well as dynamic biophysicochemical interactions. These interactions lead to the formation of protein coronas, particle wrapping, intracellular uptake and biocatalytic processes that could have biocompatible or bioadverse outcomes. For their part, the biomolecules may induce phase transformations, free energy releases, restructuring and dissolution at the nanomaterial surface. Probing these various interfaces allows the development of predictive relationships between structure and activity that are determined by nanomaterial properties such as size, shape, surface chemistry, roughness and surface coatings. This knowledge is important from the perspective of safe use of nanomaterials.