Narrow Results

Nanocarriers that can Kill Tumors with Drugs and DNA.

Over the past two decades, there has been a surge in the development of nanoparticle technologies for therapeutic applications. In the area of skin wound healing, silver nanoparticles have been long used as topical antibacterials, but new types of multifunctional nanosystems that can provide more comprehensive therapeutic effects on wounds are being rolled out. The ability to provide a reservoir of bioactive molecules that can be released over time is a feature of many of these systems, which is critically important for nonhealing wounds, where there often is a persistent bacterial load and a chronic lack of growth factors necessary for healing. A great advantage of nanosystems is that by virtue of their extremely small size, they can be easily incorporated into a wide variety of topical treatments that are currently available for use in the clinic. For example, nanoparticles can be easily introduced into decellularized skin products as well as other bioengineered skin substitutes. The design options available for the nanocarriers are very diverse, including encapsulating the drug in the particle's core or presenting it on the outside of the particle, which can also be decorated with a targeting agent, and the ability to change conformation in response to environmental cues (e.g., pH). These various design elements have been optimized differently to treat different types of wounds.

The recent development of biomedical nanotechnology is providing the appropriate know-how to build novel nanocarriers/nanocapsules to be used in the pharmaceutical industry for delivery of drugs and/or therapeutic payloads to specific cells. DNA is an extremely suitable polymer for the generation of nanocapsules being biocompatible, stable and chemically modifiable. Moreover, the simple four bases mechanism allows the auto-assembly of geometrically defined systems. In this review, we describe the general properties of DNA nanocarriers, how they can be functionalized for different tasks, their interaction with cellular systems and we provide an outlook of their use in a therapeutic perspective.

Introduction: The lymphatic system has a critical role in the immune system's recognition and response to disease and it is an additional circulatory system throughout the entire body. Extensive multidisciplinary investigations have been carried out in the area of lymphatic delivery, and lymphatic targeting has attracted a lot of attention for providing preferential chemotherapy and improving bioavailability of drugs that undergo hepatic first-pass metabolism.

Areas covered: This review focuses on progress in the field of lymphatic therapeutics and diagnosis. Moreover, the anatomy and physiology of the lymphatic system, particulate drug carriers and different physicochemical parameters of both modified and unmodified particulate drug carriers and their effect on lymphatic targeting are addressed.

Expert opinion: Particulate drug carriers have encouraged lymphatic targeting, but there are still challenges in targeting drugs and bioactives to specific sites, maintaining desired action and crossing all the physiological barriers. Lymphatic therapy using drug-encapsulated lipid carriers, especially liposomes and solid lipid nanoparticles, emerges as a new technology to provide better penetration into the lymphatics where residual disease exists. Size is the most important criteria when designing nanocarriers for targeting lymphatic vessels as the transportation of these particles into lymphatic vessels is size dependent. By increasing our understanding of lymphatic transport and uptake, and the role of lymphatics in various diseases, we can design new therapeutics for effective disease control.

Nanomaterials with different morphologies and functions have been widely developed. Among them, the nanotheranostic systems designed and simultaneously used for therapeutics and diagnostics draw particular attention. To achieve the multifunctionality in one nanoformulation, typically four components are included: nanocarriers, targeting ligand, imaging domain and therapeutics. This review is aimed at introducing some examples of possibilities for the different components in a nanotheranostic system.

Nano-emulsions, also called sub-micrometer emulsions, are one of the most important nanocarriers in nanomedicine. More than 40% active susbtances are hydrophobic and therefore they are difficult to be formulated using conventional approaches. Nano-emulsion systems are considered as new vehicles for hydrophobic drug administration because they can enhance the penetration and absorption of these hydrophobic active compounds and provide safer and more patient-compliant dosage forms. This chapter describes the conception and methods of preparation of nano-emulsions, their characterization methods and their applications in pharmacetical areas.