Multifunctional Nanocapsules Research Articles

Gold nanoshelled liquid perfluorocarbon magnetic nanocapsules: a nanotheranostic platform for bimodal ultrasound/magnetic resonance imaging guided photothermal tumor ablation.

Imaging guided ablation therapy has been applied in both biomedical research and clinical trials and turned out to be one of the most promising approaches for cancer treatment. Herein, the multifunctional nanocapsules were fabricated through loading perfluorooctylbromide (PFOB) and superparamagnetic iron oxide nanoparticles (SPIOs) into poly(lactic acid) (PLA) nanocapsules (NCs), followed by the formation of PEGylated gold nanoshell on the surface. The resulting multi-component NCs were proved to be able to act as nanotheranostic agent to achieve successful bimodal ultrasound (US)/magnetic resonance imaging (MRI) guided photothermal ablation in human tumor xenograft models non-invasively. Such a single theranostic agent with the combination of real-time US and high-resolution MR imaging would be of great value to offer more comprehensive diagnostic information and dynamics of disease progression for the accurate location of therapeutic focusing spot in the targeted tumor tissue, showing great potential as an effective nanoplatform for contrast imaging guided photothermal therapy.

Multifunctional Nanocapsules for Simultaneous Encapsulation of Hydrophilic and Hydrophobic Compounds and On-Demand Release

Cocktail therapy by delivering multiple drugs to diseased cells can elicit synergistic therapeutic effects and better modulate the complex cell-signaling network. Besides selection of drug combinations, a difficulty in delivery is how to encapsulate drugs with various solubility into a common vehicle, particularly when both hydrophobic and hydrophilic compounds are involved. Furthermore, it is highly desirable that the drug release profile can be controlled in an on-demand fashion for balanced therapeutic and side effects. On the basis of a simple and scalable double emulsion approach, we report a new class of nanocapsules that can solve these problems simultaneously. Further linking the nanocapsules with peptides targeting cell surface integrins leads to significantly enhanced cell uptake of the nanocapsules. Intracellular drug release triggered by external stimuli has also been achieved without affecting cell viability. Further development of this technology should open exciting opportunities in treating tough diseases such as cancer, cardiovascular diseases, neurological disorders, and infectious diseases.

Core/Shell Structured Hollow Mesoporous Nanocapsules: A Potential Platform for Simultaneous Cell Imaging and Anticancer Drug Delivery

A potential platform for simultaneous anticancer drug delivery and MRI cell imaging has been demonstrated by uniform hollow inorganic core/shell structured multifunctional mesoporous nanocapsules, which are composed of functional inorganic (Fe(3)O(4), Au, etc.) nanocrystals as cores, a thin mesoporous silica shell, and a huge cavity in between. The synthetic strategy for the creation of huge cavities between functional core and mesoporous silica shell is based on a structural difference based selective etching method, by which solid silica middle layer of Fe(2)O(3)@SiO(2)@mSiO(2) (or Au@SiO(2)@mSiO(2)) composite nanostructures was selectively etched away while the mesoporous silica shell could be kept relatively intact. The excellent biocompatibility of obtained multifunctional nanocapsules (Fe(3)O(4)@mSiO(2)) was demonstrated by very low cytotoxicity against various cell lines, low hemolyticity against human blood red cells and no significant coagulation effect against blood plasma. The cancer cell uptake and intracellular location of the nanocapsules were observed by confocal laser scanning microscopy and bio-TEM. Importantly, the prepared multifunctional inorganic mesoporous nanocapsules show both high loading capacity (20%) and efficiency (up to 100%) for doxorubicin simultaneously because of the formation of the cavity, enhanced surface area/pore volume and the electrostatic interaction between DOX molecules and mesoporous silica surface. Besides, the capability of Fe(3)O(4)@mSiO(2) nanocapsules as contrast agents of MRI was demonstrated both in vitro and in vivo, indicating the simultaneous imaging and therapeutic multifunctionalities of the composite nanocapsules. Moreover, the concept of multifunctional inorganic nanocapsules was extended to design and prepare Gd-Si-DTPA grafted Au@mSiO(2) nanocapsules for nanomedical applications, further demonstrating the generality of this strategy for the preparation of various multifunctional mesoporous nanocapsules.

Prodrugs Forming High Drug Loading Multifunctional Nanocapsules for Intracellular Cancer Drug Delivery

Anticancer drugs embedded in or conjugated with inert nanocarriers, referred to as nanomedicines, show many therapeutic advantages over free drugs, but the inert carrier materials are the major component (generally more than 90%) in nanomedicines, causing low drug loading contents and thus excessive uses of parenteral excipients. Herein, we demonstrate a new concept directly using drug molecules to fabricate nanocarriers in order to minimize use of inert materials, substantially increase the drug loading content, and suppress premature burst release. Taking advantage of the strong hydrophobicity of the anticancer drug camptothecin (CPT), one or two CPT molecule(s) were conjugated to a very short oligomer chain of ethylene glycol (OEG), forming amphiphilic phospholipid-mimicking prodrugs, OEG-CPT or OEG-DiCPT. The prodrugs formed stable liposome-like nanocapsules with a CPT loading content as high as 40 or 58 wt % with no burst release in aqueous solution. OEG-DiCPT released CPT once inside cells, which showed high in vitro and in vivo antitumor activity. Meanwhile, the resulting nanocapsules can be loaded with a water-soluble drug-doxorubicin salt (DOX.HCl)-with a high loading efficiency. The DOX.HCl-loaded nanocapsules simultaneously delivered two anticancer drugs, leading to a synergetic cytotoxicity to cancer cells. The concept directly using drugs as part of a carrier is applicable to fabricating other highly efficient nanocarriers with a substantially reduced use of inert carrier materials and increased drug loading content without premature burst release.

From polymeric particles to multifunctional nanocapsules for biomedical applications using the miniemulsion process

AbstractThe miniemulsions process represents a versatile tool for the formation of polymeric nanoparticles consisting of different kinds of polymer as obtained by a variety of polymerization types ranging from radical, anionic, cationic, enzymatic polymerization to polyaddition, and polycondensation. The process perfectly allows the encapsulation of hydrophilic and hydrophobic liquids and solids in polymeric shells, molecularly dissolved dyes or other components. In combination with a specific functionalization of the nanoparticles' or nanocapsules' surfaces and the possibility to release substances in a defined way from the interior, complex nanoparticles or nanocapsules are obtained, which are ideally suited for application in biomedical application as marker and targeted drug‐delivery system. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 493–515, 2010