The Emerging Role of Nanotechnology in Cell and Organ Transplantation

Abstract

Transplantation is often the only choice many patients have when suffering from end-stage organ failure. Although the quality of life improves after transplantation, challenges, such as organ shortages, necessary immunosuppression with associated complications, and chronic graft rejection, limit its wide clinical application. Nanotechnology has emerged in the past 2 decades as a field with the potential to satisfy clinical needs in the area of targeted and sustained drug delivery, noninvasive imaging, and tissue engineering. In this article, we provide an overview of popular nanotechnologies and a summary of the current and potential uses of nanotechnology in cell and organ transplantation.

Figure 1

Schematic of synthesis and functionalization of particles. Size, shape and porosity: Mesoporous silicon nanoparticles with various aspect ratios and various pore sizes (e.g. Discoid nanoparticle, semi-spheres, nanorods). Surface modifications of particles: Positive/negative surface charges, peptides, antibodies. Payload nanoparticles: named second-stage carriers (SSNs) are nanoparticles within the approximate size range of 5-100 nm in diameter (e.g. liposomes, micelles, inorganic/metallic nanoparticles, and carbon structures).

Figure 2

Scanning electron microscopy image of the cross section of a silicon – silicon nitride nanochannel membrane designed for constant and sustained drug release (A); 3D rendering of the structure of a drug delivery implant incorporating a nanochannel membrane (B); zero-order sustained release can achieve and maintain plasma level of drugs within the therapeutic window for the duration of treatment (C). This has potential for improved efficacy and reduction of adverse side effects of treatment as compared to the conventional bolus administration of therapeutics.

Figure 3

Sections of transplanted rat hearts VVG stained. Chronically rejecting heart shows fully occluded vessel (A). Recipient treated with RhoA inhibitor delivered from nanochamber shows healthy unoccluded vessels (B).

Figure 4

3D rendering of a drug delivery implant for the remotely controlled administration of therapeutics (A). The implant comprises an electrode-coated nanochannel membrane for tuning a low-power applied electric field and tune drug release according to need. Drug administration can be synchronized to the biological clock to maximize the efficacy of treatment (B).

Figure 5

3D rendering of a nanochannel encapsulation of insulin secreting cells. The encapsulation creates a protective environment to improve graft survival and to promote rapid vascularization post transplantation. The encapsulation may supply the graft with oxygen, nutrients, growth factor and immunosuppressive agents in situ, to promote long term viability and abrogate rejection.