Micro/Nanostructured Polymeric Systems for Biomedical and Pharmaceutical Applications

Abstract

This review provides an outline of the polymeric micro/nanostructured advanced systems that are suited for the controlled and targeted administration of, specifically, nonconventional drugs. The contribution of new trends in drug-delivery technology is focused on two major parts, dealing with brief surveys of: the biodegradable/bioerodible polymeric systems used in the formulation of micro/nanoparticles and techniques used in the preparation of micro/nanoparticles for their biomedical application in cancer treatment specifically, in inflammation pathologies, as oxygen carriers (blood substitutes) and in tissue-engineering practice. A small discussion of the future perspectives of the described systems is also given.

Pullulan-based nanoparticles as carriers for transmucosal protein delivery

“…In recent years, the most frequently explored polysaccharide for the design of nanodelivery systems was chitosan, a cationic polymer composed of repeating β-(1,4)-linked N-acetylglucosamine and D-glucosamine units, which is obtained by chitin deacetylation and assumes different molecular weights and deacetylation degrees (Chiellini et al, 2008;Hassani et al, 2012;Mizrahy and Peer, 2012). Apart from the reported biocompatibility and biodegradability (Dornish et al, 1997;Grenha et al, 2010a;Hirano et al, 1988), the most outstanding properties of chitosan rely on its mucoadhesive character (Lehr et al, 1992) and demonstrated ability to potentiate transmucosal absorption both as molecule (Artursson et al, 1994;Borchard et al, 1996;Portero et al, 2002) and in the form of nanoparticle (Al-Qadi et al, 2012;De Campos et al, 2001;Fernández-Urrusuno et al, 1999a;Prego et al, 2005a;Yamamoto et al, 2005).…”

“…Another of those molecules is pullulan, a neutral polymer consisting of α-(1,6)-linked maltotriose residues, which in turn are composed of three glucose molecules connected to each other by an α-(1,4) glycosidic bond (Chiellini et al, 2008;Mizrahy and Peer, 2012;Namazi et al, 2011). Pullulan is produced from starch by the fungus Aureobasidium pullulans and evidences water solubility (Leathers, 2003;Rekha and Chandra, 2007).…”

Natural carriers for application in tuberculosis treatment

“…Carboxymethylcellulose is a cellulose derivative in which the glucopyranose backbone presents carboxymethyl groups attached to some of its hydroxyl moieties. The application of these polymers in drug delivery is widely reported, as they evidence biocompatibility, biodegradability and, in some cases, mucoadhesive properties, which are more pronounced in chitosan (Beneke et al, 2009, Chiellini et al, 2008, Sudhakar et al, 2006. Gelatin is a protein derived from collagen, with reported biocompatibility and biodegradability (Chiellini et al, 2008, Malafaya et al, 2007.…”

“…The application of these polymers in drug delivery is widely reported, as they evidence biocompatibility, biodegradability and, in some cases, mucoadhesive properties, which are more pronounced in chitosan (Beneke et al, 2009, Chiellini et al, 2008, Sudhakar et al, 2006. Gelatin is a protein derived from collagen, with reported biocompatibility and biodegradability (Chiellini et al, 2008, Malafaya et al, 2007. Albumin microspheres are also described (Yeboah and D'souza, 2009), but their application focuses on the oral administration of vaccines, therefore being out of the scope of this review.…”

Chitosan nanoparticles: a survey of preparation methods

“…These drug delivery carriers should exhibit characteristics that include: capacity for drug association, ability to enhance their physicochemical stability and protection of encapsulated drugs from carrier production to release. Furthermore, in many cases, carriers are expected to regulate the drug release profile, while allowing an intimate contact between molecules and mucosal barriers, contributing to their epithelial permeation (Chiellini et al 2008, Luppi et al 2010). …”