Modified chitosan hydrogels as drug delivery and tissue engineering systems: present status and applications

Abstract

Chitosan, a natural cationic polysaccharide, is prepared industrially by the hydrolysis of the aminoacetyl groups of chitin, a naturally available marine polymer. Chitosan is a non-toxic, biocompatible and biodegradable polymer and has attracted considerable interest in a wide range of biomedical and pharmaceutical applications including drug delivery, cosmetics, and tissue engineering. The primary hydroxyl and amine groups located on the backbone of chitosan are responsible for the reactivity of the polymer and also act as sites for chemical modification. However, chitosan has certain limitations for use in controlled drug delivery and tissue engineering. These limitations can be overcome by chemical modification. Thus, modified chitosan hydrogels have gained importance in current research on drug delivery and tissue engineering systems. This paper reviews the general properties of chitosan, various methods of modification, and applications of modified chitosan hydrogels.

Manufacturing and evaluation of Chitosan, PVA and Aloe Vera hydrogels for skin applications

“…and Perea-Mesa, Y.P., Manufacturing and evaluation of Chitosan, PVA and Aloe Vera hydrogels for skin applications DYNA, 84(203), pp. 134-142, December, 2017. attracted interest to a wide range of biomedical and pharmaceutical applications, cosmetics, and tissue engineering [1]. The use of biodegradable polymeric systems as implantable drug delivery systems is desirable, since the devices are degraded and eliminated from the body.…”

“…Thanks to its biocompatibility, hydrogels may be put in direct contact with wounds as they help hydrating the dead tissue, providing not-reactive materials that do not cause irritation and cooling the surface of the wound, help reducing pain and increasing patient's acceptance [1][2][3].…”

Possible role of nanocarriers in drug delivery against cervical cancer

“…Vaginally applied gels are established and known therapeutics, containing drugs and active ingredients which can refurbish physiological pH, moisturize and lubricate, be a contraceptive or labor inducer, and/or have microbicide activity [113]. Additional to swellability, hydrogels encompass physical properties such as mechanical resistance, permeability, surface features, and biocompatibility that can be altered through structural transformations [114]. …”

Self-assembled drug delivery system based on low-molecular-weight bis-amide organogelator: synthesis, properties and in vivo evaluation

“…For example, injectable in situ forming implant based on N-steroyl-L-alanine methyl ester and N-steroyl-Lalanine ethyl ester have been successfully prepared as a matrix where the therapeutic agents could be entrapped and then released from the organogels via diffusion or degradation (Plourde et al, 2005). Subcutaneous administration is frequently used as a route since it is convenient to administrate, and can avoid the first-pass metabolism, prolong the retention time, reduce the frequency of administration and improve the bioavailability of drugs (Packhaeuser et al, 2004;Madan et al, 2009;Giri et al, 2012;Ghasemi et al, 2016). The organogel, however, could be injected through syringe needle with the aid of ''gelation inhibitor'', which belongs to some of the amphiphilic solvents.…”