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.

Understanding biophysicochemical interactions at the nano–bio interface

Metal Organic Frameworks in Biomedicine Patricia Horcajada,* Ruxandra Gref, Tarek Baati, Phoebe K. Allan, Guillaume Maurin, Patrick Couvreur, G erard F erey, Russell E. Morris, and Christian Serre* Institut Lavoisier, UMR CNRS 8180, Universit e de Versailles St-Quentin en Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France Facult e de Pharmacie, UMR CNRS 8612, Universit e Paris-Sud, 92296 Châtenay-Malabry Cedex, France Institut Charles Gerhardt Montpellier, UMR CNRS 5253, Universit e Montpellier 2, 34095 Montpellier cedex 05, France EaStChem School of Chemistry, University of St. Andrews Purdie Building, St Andrews, KY16 9ST U.K.

Metal-organic frameworks in biomedicine.

Engineered nanoparticles have the potential to revolutionize the diagnosis and treatment of many diseases; for example, by allowing the targeted delivery of a drug to particular subsets of cells. However, so far, such nanoparticles have not proved capable of surmounting all of the biological barriers required to achieve this goal. Nevertheless, advances in nanoparticle engineering, as well as advances in understanding the importance of nanoparticle characteristics such as size, shape and surface properties for biological interactions, are creating new opportunities for the development of nanoparticles for therapeutic applications. This Review focuses on recent progress important for the rational design of such nanoparticles and discusses the challenges to realizing the potential of nanoparticles.

Strategies in the design of nanoparticles for therapeutic applications

Biodegradable polymeric nanoparticles based drug delivery systems

Infectious Diseases Society of America.

Opsonization, biodistribution, and pharmacokinetics of polymeric nanoparticles

Interpenetrating polymer network (IPN), random copolymer, and homopolymer nanoparticles of acrylamide and acrylic acid were prepared using an inverse emulsion polymerization technique. Differential scanning calorimetry and Fourier-transform infrared spectroscopy were used to examine the molecular structure of the prepared polymeric nanoparticles. The spherical morphology and size (∼250 nm diameter) of the nanoparticles was confirmed using scanning electron microscopy. Dynamic light scattering was used to determine the monodispersity of the particle size distribution and examine the thermally responsive swelling properties of the polymeric nanoparticle structures. Of the particle systems studied, only the IPN nanoparticles exhibited a unique, rapid sigmoidal swelling transition with temperature. These systems also achieved a much larger relative swelling volume compared to random copolymer and homopolymer particles comprised of acrylamide and acrylic acid. Increased cross-linker density resulted in an over...

Thermally Responsive Swelling Properties of Polyacrylamide/Poly(acrylic acid) Interpenetrating Polymer Network Nanoparticles

The objective of this study was to synthesize and characterize a thermally responsive polymer-metal nanocomposite system comprised of a solid gold nanoparticle core and thermally responsive interpenetrating polymer network (IPN) shell, which was surface functionalized or PEGylated with a covalently bound linear poly(ethylene glycol) chain layer Gold nanoparticles (50 nm diameter) were prepared using standard gold chloride and citrate reduction method These particles were then encapsulated inside of a polyacrylamide (PAAm)/poly(acrylic acid) (PAA) IPN shell via an in situ inverse emulsion polymerization The surface of the nanocomposite system was then PEGylated via covalent grafting of a linear methoxy-PEG-N-hydroxysuccinimide (MW 3400) to the primary amine groups of the PAAm network Scanning and transmission electron microscopy were used to confirm the successful synthesis and encapsulation of gold nanoparticles within the IPN shell Dynamic light scattering was used to examine the temperature swelling response of the IPN particles Zeta-potential analysis was used to confirm the successful PEGylation of the final nanocomposite system

Temperature-responsive polymer-gold nanocomposites as intelligent therapeutic systems.

Poor bioavailability associated with poorly water-soluble compounds remains a challenging issue in drug development. Particle engineering may be used to improve the physicochemical properties of poorly water-soluble compounds, thereby enhancing the bioavailability. Cryogenic technologies, including spray freeze drying (SFD), spray freezing into liquid (SFL), and thin film freezing (TFF), are “bottom-up” precipitation processes to generate amorphous nanostructured aggregates with significantly enlarged surface area, higher dissolution rates, and supersaturation, via rapidly inducing nucleation followed by particle growth arrest through stabilization via polymers and solidification of the solvent. This chapter provides detailed description of each cryogenic process, formulation guidelines, and characterization analyses. Finally, examples of cryogenically engineered drug compositions with improved in vitro and in vivo macroscopic performance are provided to illustrate the potential benefits of cryogenic technologies, especially TFF. The current authors would like to thank and acknowledge the significant contribution of the previous authors of this chapter from the first edition. This current second edition chapter is a revision and update of the original authors’ work.

Pharmaceutical Cryogenic Technologies

Systems and methods for creating a hydraulic barrier at an interface between high and low permeability regions that may exist in high permeability-contrast subterranean formations. These systems and methods may include providing injection and/or production wells that are completed within the high and/or low permeability regions, supplying a pore throat blocking agent to an interface between the high and low permeability regions, and forming the hydraulic barrier at the interface. The pore throat blocking agent may be sized to substantially flow through the high permeability region while being substantially blocked, or occluded, from the low permeability region. In some embodiments, the hydraulic barrier may be greater than one acre (0.4 hectare) in area. In some embodiments, the subterranean formation may include an oil reservoir. In some embodiments, the high and/or low permeability formations may be swept concurrently and/or independently to remove oil from the oil reservoir.

Donald E. Owens

Papers

Opsonization, biodistribution, and pharmacokinetics of polymeric nanoparticles

Thermally Responsive Swelling Properties of Polyacrylamide/Poly(acrylic acid) Interpenetrating Polymer Network Nanoparticles

Temperature-responsive polymer-gold nanocomposites as intelligent therapeutic systems.

Pharmaceutical Cryogenic Technologies

Systems and methods for hydraulic barrier formation to improve sweep efficiency in subterranean oil reservoirs