Theranostic applications of nanomaterials in cancer: drug delivery, image-guided therapy, and multifunctional platforms

Abstract

Successful cancer management depends on accurate diagnostics along with specific treatment protocols. Current diagnostic techniques need to be improved to provide earlier detection capabilities, and traditional chemotherapy approaches to cancer treatment are limited by lack of specificity and systemic toxicity. This review highlights advances in nanotechnology that have allowed the development of multifunctional platforms for cancer detection, therapy, and monitoring. Nanomaterials can be used as MRI, optical imaging, and photoacoustic imaging contrast agents. When used as drug carriers, nanoformulations can increase tumor exposure to therapeutic agents and result in improved treatment effects by prolonging circulation times, protecting entrapped drugs from degradation, and enhancing tumor uptake through the enhanced permeability and retention effect as well as receptor-mediated endocytosis. Multiple therapeutic agents such as chemotherapy, antiangiogenic, or gene therapy agents can be simultaneously delivered by nanocarriers to tumor sites to enhance the effectiveness of therapy. Additionally, imaging and therapy agents can be co-delivered to provide seamless integration of diagnostics, therapy, and follow-up, and different therapeutic modalities such as chemotherapy and hyperthermia can be co-administered to take advantage of synergistic effects. Liposomes, metallic nanoparticles, polymeric nanoparticles, dendrimers, carbon nanotubes, and quantum dots are examples of nanoformulations that can be used as multifunctional platforms for cancer theranostics. Nanomedicine approaches in cancer have great potential for clinically translatable advances that can positively impact the overall diagnostic and therapeutic process and result in enhanced quality of life for cancer patients. However, a concerted scientific effort is still necessary to fully explore long-term risks, effects, and precautions for safe human use.

Figure 1

Schematic representation of a multifunctional polymeric nanoparticle for image guided therapy.

Figure 2

Schematic representation of a micelle entrapping a water insoluble drug.

Figure 3

SEM image of gold nanoparticles

Figure 4

An athymic nude mouse bearing a subcutaneous A431 tumor received an intraperitoneal injection of IRDye 680 BoneTag (4 nmole) 2 weeks prior to receiving the tumor specific optical probe, IRDye 800CW EGF (1 nmole). The mouse was imaged 72 hours later on the Pearl Imaging System (LI-COR Biosciences). Fluorescent signal for IRDye 680 BoneTag is represented in grayscale and IRDye 800CW EGF in pseudo color. Provided to: Anthony J McGoron, PhD, Florida International University, by LI-COR Biosciences.

Figure 5

SEM image of PLGA NPs simultaneously loaded with indocyanine green and doxorubicin.

Figure 6

Schematic representation of a dendrimer.

Figure 7

Schematic representation of a quantum dot