Current Drug Metabolism - Volume 14, Issue 8, 2013

Recent developments in nanotechnology have paved the way for using quantum dots (QDs) in nanodiagnostics and nanotherapeutics. Careful design and preparation of QDs are guided by these application-specific requirements. QDs will probably be one of the first nanomaterial to reach clinical applications, however many challenges in this field have yet to be overcome. In this article, we present an extensive review of the pharmacokinetic properties of QDs. The representative studies responsible for observing quantitative determination of QDs biodistribution in vivo are presented. The effects of size, surface chemistry, and target moiety on their pharmacokinetics are discussed. Finally, future directions for improving the pharmacokinetics of QDs and perspectives in the field are discussed. The understanding of its absorption, distribution, metabolism, and excretion from the body will provide important guidelines for the successful clinical use of QDs.

Advancements in the design and synthesis of polymer-based nanoassemblies and nanoparticles, combined with achievements in nanotechnology and medicine, have resulted in remarkable applications of polymer nanosystems in the areas of nanomedicine and pharmaceutical sciences. However, a complete understanding of the absorption, distribution, metabolism, and elimination (ADME) processes of such polymer nanosystems in living systems has not been achieved. The influences of the pharmacokinetic parameters of polymer nanomaterials on the ADME processes are reviewed in this article, with discussions of the absorption and transportation of polymer nanoparticles across biological barriers, the factors affecting the bodily distribution of polymer nanocarriers, the transformation of polymer nanomaterials in vivo, the elimination pathway of polymer nanoparticles from biological systems, and perspectives of future pharmacokinetics and safety investigations of polymer-based nanoassemblies. A full and better understanding of the pharmacokinetic parameters of polymer-based nanomaterials is of vital importance in developing polymer nanosystems with optimal pharmacokinetics and biological safety for applications in nanomedicine and the pharmaceutical industry.

In recent years, nanotechnology research has made great strides in the area of pharmacy, especially for drug delivery systems. Polymeric nanoparticles provide significant stability in anti-neoplastic drug research and have demonstrated the ability to solve the problems of therapeutic efficacy and diagnostic sensitivity. In this review, we describe the specific advantages of polymeric nanoparticles and their applications for a drug delivery system. The latest research on PHA-based polymeric nanoparticles and PLGA is also discussed.

As the number of applications of quantum dots (QDs) grows, the likelihood of exposure increases. Because these metals have the potential for detrimental environmental and health effects, concerns have been raised over our lack of understanding about the fate of these products. Among various types of QDs, cadmium-based quantum dots attract the greatest attention due to their wide applications. To properly assess the potential risk of cadmium-containing QDs, we summarize the current state of academic knowledge on the toxicity of cadmium-based QDs.

In the past three decades, the application of nanotechnology in ophthalmology has gained considerable progress for the treatment of ocular diseases including anterior and posterior diseases. Results strongly suggest that delivery of ocular medicines, especially those based on macromolecular agents such as proteins, peptides, and nucleotides, are greatly enhanced by the use of nanotechnology. Generally, ophthalmic drugs are delivered to ocular tissues by precorneal instillation and intravitreal injections. An ideal ocular drug delivery system should have certain desirable properties, such as excellent corneal and conjunctival penetration, prolonged residence time, sustained release, and easy administration. It should also be nonirritating and noncytotoxic. This review places in perspective the importance of nanoparticles in the pharmacokinetics and disposition of ocularly administered drugs. Furthermore, the safety and compatibility of nanoparticles for ocular administration are specifically discussed.

Graphene possesses a wide range of potential biomedical applications because of the unique physical and chemical properties. However, the side effects of grapheme and its derivatives on a number of biological models even on human body are still not very clear. Therefore, to properly assess the potential risk of grapheme and its derivatives, we summarize the current state of academic knowledge on their toxicity.

Nanomaterials possess enormous potential for biomedical applications, while some of the most promising nanomaterials currently under investigation demonstrate prolonged tissue retention and contain heavy metals. This article investigates the pharmacokinetics of magnetic nanoparticles (MNPs) to help identify promising candidates with optimal pharmacokinetics and clearance from the body for biomedical use and synthesize nanomaterials ideal for biomedical use. The term ‘magnetic nanoparticles’ (MNPs) refers to nanoparticles with ferromagnetism. Such nanoparticles have special characteristics, and many in the field of biological field have undertaken research involving, e.g., immobilized enzymes and proteins, biological cells, macromolecular separation, drug carriers, and targeted, immune, biological sensors.

Carbon nanotubes have shown broad potential in biomedical applications, given their unique mechanical, optical, and chemical properties. Functionalized carbon nanotubes not only can deliver drug into specific organs but also can inherently produce heating by near-infrared laser radiation for cancer therapy. However, the toxicological and pharmacological profile of such carbon nanotube system will have to be determined prior to any clinical study undertaken. For providing a guide to develop safe drug carriers, this review discusses the functionalization, toxicity and pharmacokinetics of carbon nanotubes. Lastly, the drug delivery and thermal ablation on carbon nanotubes are proposed.

Carbon nanotubes (CNTs) find their extensive application as a promising material in medicine due to unique characteristics. However, such materials have been accompanied with potentially hazardous effects on human health. The toxicity of CNTs may vary depending on their structural characteristics, surface properties and chemical composition. To gain insight into the toxicity of CNTs in vivo and in vitro, we summarize contributing factors for the toxic effects of CNTs in this review. In addition, we elaborate on the toxic effects and mechanisms in target sites at systemic, organic, cellular, and biomacromolecule levels. Various issues are reported to be effected when exposed to CNTs including (1) blood circulation, (2) lymph circulation, (3) lung, (4) heart, (5) kidney, (6) spleen, (7) bone marrow, and (8) blood brain barrier. Though there have been published reports on the toxic effects of CNTs to date, more studies will still be needed to gain full understanding of their potential toxicity and underlying mechanisms.

Polymeric micelles (PMs) have shown promising applications for the drug delivery since they can improve the low water solubility of hydrophobic drugs, reduce toxicity of the drug, protect unstable drugs from degradation or metabolism, and prolong the time of blood circulation. The incorporation of drugs to PMs can fundamentally alter the drug's pharmacokinetics (PK) to enable their efficient therapeutic activity. This article reviews the key progress to date about the work of the PK of various PMs in oncology. First, the common techniques to incorporate the drugs to PMs have been introduced. The PK of PMs for typical anti-tumor drugs (Taxels, Doxorubicin, Cisplatin, camptothecins) according to different amphiphilic polymers is discussed in detail. The strengths and limitations of PM formulations for the PK also have been included.

Carbon nanotubes (CNT) are allotropes of carbon with a cylindrical nanostructure. They have recently aroused great interests as drug carriers, but their pharmacokinetic profiles which determine their potentials in clinical application are yet to be fully understood. Therefore, this overview attempts to outline the processes of absorption, distribution, metabolism and excretion (ADME) that govern the pharmacokinetics of CNT. In addition, the molecular mechanisms of intracellular internalization and drug release are also discussed.