Nanotechnology in Drug Delivery

Abstract

Nanotechnology involves manipulating matter at the nanoscale (<1000 nm); that is, manipulations at less than thousandth of a millimeter, and for drug delivery applications this typically takes the form of creating nanoparticles (5 ∼ 800 nm) that are then used to package drug molecules and genes. By packaging pharmacologically active compounds within nanoparticles, nanomedicines are created. It is possible to control drug biodistribution and achieve therapeutic benefit with these nanomedicines. This chapter outlines the various chemistries and nanomedicine preparation strategies that have been used to produce nanoparticles and highlights the drug delivery benefits that are achievable from these nanoscale arrangements. The chemical compounds used to construct these nanomedicines are as follows: low molecular weight self‐assembling amphiphiles, self‐assembling amphiphilic polymers, polymer–drug conjugates, water insoluble polymers/cross‐linked polymers, dendrimers, and carbon nanotubes. Engineering of these particles has produced nanomedicines that target drugs and genes to tumors and improve the brain delivery of peptides and other molecules. These particles are also capable of promoting oral drug absorption and drug transport across other biological barriers such as the cornea and the skin. Only a few of these technologies are commercially available presently, such as liposomes (e.g., Doxil®), low molecular weight micelles (e.g., Fungizone®), and polymer–drug conjugates (Oncaspar®); but the therapeutic benefits being observed in both preclinical studies and early clinical testing suggest that more of these technologies will emerge into the patient arena in the future.

Click Chemistry for Drug Delivery Nanosystems

“…A core-shell micelle was prepared by self-assembly of a poly(trimethylsilyl propargyl methacrylate)-b-poly[poly(ethylene glycol) methyl ether methacrylate] obtained by RAFT polymerization, after removal of TMS protecting groups. Then, the pendant alkyne groups at the core were used as reactive functional groups for cross-linking via CuAAC (Cu wire, Cu(PPh 3 ) 3 Br, DIPEA, THF-H 2 O), and as ligands for Co 2 (CO) 8 to generate a macromolecular carrier of the antitumor agents based on (alkyne)Co 2 (CO) 6 . It is worth noting that while Coloaded micelles were highly toxic to L929 fibroblast cells, the permanent encapsulation of Co complex in the cross-linked NP was shown to reduce toxicity.…”

“…between dithiols and a cucurbit [6]uril carrying 12 allyloxy groups at the periphery for preparation of polymer nanocapsules with high stability and relatively narrow size distribution (Fig. 21).…”

“…In various recent examples, Li and Fig. 21 Synthesis of (allyloxy) 12 cucurbit [6]uril polymer nanocapsules via TEC cross-linking. Reprinted with permission from ref (90).…”

“…Organic synthesis as a discipline has accompanied this evolution of drug delivery into a mature field by providing synthetic tools for efficient bioconjugation of drugs, polymers, or targeting ligands, and preparation of novel building blocks and polymeric materials for construction of DDS with new properties (6). Indeed, chemistry is a central science where phenomena occur and properties are defined at the molecular level.…”

Adsorption of BSA (Bovine Serum Albuminum) and lysozyme on poly(vinyl acetate) particles

“…Although PVAc is well known for its excellent adhesive properties [28] , PVAc is also used in a broad range of applications, including medical applications, due to its biocompatibility [29][30][31] . For this reason, Pinto and coworkers [13][14][15]25,30,[32][33][34] developed a sequential two-stage process to allow for production of spherical PVAc/PVA particles with core-shell morphology to be used as embolizers.…”