Polysaccharide-based micro/nanocarriers for oral colon-targeted drug delivery

Abstract

Oral colon-targeted drug delivery has attracted many researchers because of its distinct advantages of increasing the bioavailability of the drug at the target site and reducing the side effects. Polysaccharides that are precisely activated by the physiological environment of the colon hold greater promise for colon targeting. Considerable research efforts have been directed towards developing polysaccharide-based micro/nanocarriers. Types of polysaccharides for colon targeting and in vitro/in vivo assessments of polysaccharide-based carriers for oral colon-targeted drug delivery are summarised. Polysaccharide-based microspheres have gained increased importance not just for the delivery of the drugs for the treatment of local diseases associated with the colon (colon cancer, inflammatory bowel disease (IBD), amoebiasis and irritable bowel syndrome (IBS)), but also for it's potential for the delivery of anti-rheumatoid arthritis and anti-chronic stable angina drugs. Besides, Polysaccharide-based micro/nanocarriers such as microbeads, microcapsules, microparticles, nanoparticles, nanogels and nanospheres are also introduced in this review.

Partial removal of protein associated with arabinoxylans: Impact on the viscoelasticity, crosslinking content, and microstructure of the gels formed

“…Smaller particles such as nanoparticles present excellent properties for use in enzymes immobilization and in drug delivery systems as they can penetrate epithelial and inflammatory cells resulting in higher and effective drug concentrations . The use of microspheres in drug delivery systems also offers numerous advantages in comparison with the conventional systems as they assure a sustained release of drug in the target site . In this regard, recent studies have focused in the fabrication of AX microparticles for potential application as colon‐targeted drug delivery systems.…”

Nanoparticles for oral delivery: Design, evaluation and state-of-the-art

“…Attempts have been made to design nanoparticles composed of ROS sensitive materials to specifically target inflamed areas of the colon in IBD. Additionally, the human colon harbors the most abundant and diverse microflora (over 400 distinct bacterial species) in the GIT, and the typical microbial load in the colon is 10 10 –10 12 CFU/ml [76,78,88]. The bacteria are predominantly anaerobic and produce a variety of enzymes (glucuronidase, xylosidase, arabinosidase, galactosidase, nitroreductase, azoreductase, deaminase, urea hydroxylase, etc.)…”

“…The bacteria are predominantly anaerobic and produce a variety of enzymes (glucuronidase, xylosidase, arabinosidase, galactosidase, nitroreductase, azoreductase, deaminase, urea hydroxylase, etc.) to accomplish fermentation of undigested contents [76,78,88]. Materials that can act as a substrate for these enzymes may find use for colon targeted delivery.…”

“…In view of this, prodrugs based on azo bonds (sulfasalazine, olsalazine and balsalazide) and glucosides (dexamethasone-21-fglucosides) have been developed to achieve colon targeting. Similarly, polymers based on natural carbohydrates (pectin, guar gum, alginic acid), or azo containing monomers (azo-polyurethanes) have been studied for colon targeted nanoparticles [88,89]. However, it is important to consider the differences in the microbiota in the healthy and diseased colon, and between different animal species, in the design of nanoparticles based on microbial enzyme substrates.…”

Synthesis of RAFT‐Mediated Amphiphilic Graft Copolymeric Micelle Using Dextran and Poly (Oleic Acid) toward Oral Delivery of Nifedipine

“…Besides, the presence of hydroxyl groups in dextran can increase the solubility of the conjugated hydrophobic part that is advantageous for biomedical application . Therefore, the conjugation of dextran and oleic acid may enhance the oral bioavailability of the hydrophobic drug toward the targeted site and reduce the side effects . Here the synthesized copolymer consists of hydrophilic (dextran and carboxylic acid of oleic acid) and hydrophobic segments (long chain methylene group of oleic acid).…”