Читать книгу Nanobiotechnology in Diagnosis, Drug Delivery and Treatment - Группа авторов - Страница 60

The polymers used as particulate vectors may be natural or synthetic, synthesized by standard polymerization chemical methods. The polymers used for diagnosis and treatment of diseases must be biocompatible, nontoxic, nonimmunogenic, and noncarcinogenic. They must also be (bio)degraded in the body, and their degradation products must be well tolerated and quickly eliminated (Laroui et al. 2011). Variable polymer chains can be used to form swollen nanosized structures called nano‐size hydrogels or nanogels. These polymer chains are usually formed by non‐covalent interactions or covalent crosslinking. Nanogels, in addition to typical nanomaterial properties, e.g. large surface area to volume ratio, are also characterized by size tunability, controlled drug release profile, excellent drug loading capacity, and responsiveness to environmental stimuli. In nanomedicine, they have attracted significant attention as imaging labels and targeted drug delivery, while reducing systemic side effects (Arunraj et al. 2014). Nanogels may be tailored to exhibit exceptional stability, low cytotoxicity, and higher blood compatibility (Chacko et al. 2012; Kong et al. 2015). They showed potential to be an oral drug delivery system (Senanayake et al. 2013). The polysaccharide chitosan nanoparticles have been also used as drug delivery systems (Figure 3.2). Polymers can be conjugated with proteins, and such nanoconstructs display reduced immunogenicity, enhanced stability, and prolong plasma half‐life (Ekladious et al. 2018). The conjugation of therapeutic agents to polymeric carriers offers improved drug solubilization, prolonged circulation, controlled release, and enhanced safety (Ekladious et al. 2019). The nano‐sized multi‐structural constructs of polymers with drugs displayed potential to improve pharmacological therapy of a variety of solid tumors. Polymer‐drug nanoconstructs promote tumor targeting throughout the increased permeability and retention effect, and in the cells, following endocytic capture, allow lysosomotropic drug delivery (Lee 2006; Gaur et al. 2008; Greco and Vicent 2009).

Figure 3.1 Nanoliposome as a carrier for drug delivery.

Figure 3.2 Chitosan nanoparticles loaded with drugs.