Particle Replication In Nonwetting Templates Research Articles

Novel Nanoparticle-Based Approaches To Target B-Cell Malignancies.

Introduction: Current approaches to the management of B-cell malignancies include the use of systemic treatments with cytotoxic chemotherapeutics that are not targeted to the tumor cell itself. By improving the ability to deliver lethal agents to the malignant cell clone, such as by targeting the unique tumor idiotype, it is possible that the therapeutic index of our current armamentarium could be improved, thereby optimizing patient outcomes. Nanoparticles represent one attractive approach in this area, since their high surface to volume ratio provides a strong driving force for diffusion into the tumor microenvironment.Methods: Studies were performed using Ramos and SUP-B8 human Burkitt's lymphoma cell lines, as well as cell lines representative of other hematologic malignancies. Commercially available nanoparticles (Qdots; Invitrogen) as well as nanoparticles generated using PRINT (particle replication in non-wetting templates) technology, were used with idiotype and control peptides.Results: A biotinylated peptide recognized by the SUP-B8 idiotype was bound to streptavidin-containing Qdots, as well as to 200 nm polymeric PRINT particles. Both of these nanoparticle types bound specifically to SUP-B8 Burkitt's lymphoma cells, as determined by the induction of a fluourescence shift by flow cytometry. These same particles showed no detectable binding to Ramos Burkitt's lymphoma cells, whose idiotype recognizes a distinct set of peptide sequences, nor to other malignant cell lines, such as RPMI 8226 and ANBL-6 multiple myeloma cells. Moreover, when these nanoparticles were coated with control biotinylated peptides, no binding was seen to any of these cell types, demonstrating the specificity of this approach. Studies utilizing a number of techniques, including fluorescence and electron microscopy, revealed that, after binding, these idiotype-specific particles were internalized by SUP-B8 cells, but not by control cells, or when control peptides were used. Studies in vivo are underway to determine if these targeted nanoparticles can be used for imaging, as well as for delivery of lethal cargoes such as doxorubicin.Conclusion: Nanoparticles can be targeted to specific neoplastic B-cell clones through the use of peptides recognized by the surface idiotype, possibly thereby sparing toxic effects to other B-cell clones, as well as to non-lymphoid cells. The ability to generate nanoparticles of various chemistries, sizes, and porosity, as well as nanoparticles containing a wide array of cargoes, will allow these to be used as platforms for the future personalization of therapy of B-cell malignancies.

Nanofabricated particles for engineered drug therapies: A preliminary biodistribution study of PRINT ™ nanoparticles

A novel method for the fabrication of polymeric particles on the order of tens of nanometers to several microns is described. This imprint lithographic technique called PRINT ™ ( Particle Replication In Non-wetting Templates), takes advantage of the unique properties of elastomeric molds comprised of a low surface energy perfluoropolyether network, allowing the production of monodisperse, shape-specific nanoparticles from an extensive array of organic precursors. This engineered nature of particle production has a number of advantages over the construction of traditional nanoparticles such as liposomes, dendrimers, and colloidal precipitates. The gentle “top down” approach of PRINT enables the simultaneous and independent control over particle size and shape, composition, and surface functionality, and permits the loading of delicate cargos such as small organic therapeutics and biological macromolecules. Thus, this single tool serves as a comprehensive platform for the rational design and investigation of new nanocarriers in medicine, having applications ranging from therapeutics to advanced diagnostics. Preliminary in vitro and in vivo studies were conducted, demonstrating the future utility of PRINT particles as delivery vectors in nanomedicine. Monodisperse 200 nm poly(ethylene glycol)-based (PEG) particles were fabricated using PRINT methodology and characterized via scanning electron microscopy and dynamic light scattering. Incubation with HeLa cells showed very little cytotoxicity, even at high concentrations. The biodistribution and pharmacokinetics of [ 125I]-labeled particles were studied in healthy mice following bolus tail vein administration. The particles were distributed mainly to the liver and the spleen with an apparent distribution t 1/2 of approximately 17 min followed by slow redistribution with a t 1/2 of 3.3 h. The volume of distribution for the central and peripheral compartments was found to be approximately 3 mL and 5 mL, respectively.

Direct Fabrication and Harvesting of Monodisperse, Shape-Specific Nanobiomaterials

A versatile "top-down" method for the fabrication of particles, Particle Replication In Nonwetting Templates (PRINT), is described which affords absolute control over particle size, shape, and composition. This technique is versatile and general enough to fabricate particles with a variety of chemical structures, yet delicate enough to be compatible with sophisticated biological agents. Using PRINT, we have fabricated monodisperse particles of poly(ethylene glycol diacrylate), triacrylate resin, poly(lactic acid), and poly(pyrrole). Monodisperse particle populations, ranging from sub-200 nm nanoparticles to complex micron-scale objects, have been fabricated and harvested. PRINT uses low-surface energy, chemically resistant fluoropolymers as molding materials, which eliminates the formation of a residual interconnecting film between molded objects. Until now, the presence of this film has largely prevented particle fabrication using soft lithography. Importantly, we have demonstrated that PRINT affords the simple, straightforward encapsulation of a variety of important bioactive agents, including proteins, DNA, and small-molecule therapeutics, which indicates that PRINT can be used to fabricate next-generation particulate drug-delivery agents.