Deoxycholate‐chitosan nanospheres fabricated by γ‐irradiation and chemical modification: Nanoscale synthesis and controlled studies

Abstract

A systematic protocol to fabricate self-assembly deoxycholate-chitosan nanospheres (DC-CsNS) by c-ray pre-irradiation and chemical modification was studied. Hydrophobic deoxycholic acid moieties were chemically conjugated to pre-irradiated chitosan. The influences of chitosan physical forms (i.e., colloid and flake) during irradiation, radiation doses, and the reaction system (heterogeneous or homogeneous) on the chemical modification and the particle shape and size were investigated. Pre-irradiation of chitosan in colloidal form produced smaller DC-CsNS particle size than that of flake form. In the heterogeneous reaction, the pre-irradiated dose influenced the DC-CsNS particle size, whereas in the homogeneous reaction all pre-irradiation doses gave an identical average size range of 30-50 nm. By pre-irradiation (10 kGy) of chitosan in colloidal form before heterogeneous chemical conjugation, it is possible to obtain DC-CsNS with an average size of 46 nm. DC-CsNS of about 50 nm in size could also be synthesized using homogeneous chemical conjugation onto non-irradiated chitosan with the addition of N-hydroxysuccinimide (NHS).

Chitosan Based Self-Assembled Nanoparticles in Drug Delivery

“…Self-assembly can be provoked by the introduction of hydrophobic moieties into the CS molecules by grafting, in order to modify its hydrophobic-hydrophilic balance. The grafting agent can be a hydrophobic moiety, such as cholesterol [ 27 ], cholic [ 28 ], and deoxycholic acid [ 29 ], or 5β-cholanic acid [ 30 ], to form micelles that can entrap lipophilic drugs or it can be the drug itself. Frequently, a water soluble CS derivative, such as glycol chitosan [ 31 ] or succinyl chitosan [ 32 ], is used instead of CS.…”

IAEA Contribution to Nanosized Targeted Radiopharmaceuticals for Drug Delivery

“…Radiation-based synthesis for NPs construction can be carried out through degradation, crosslinking, graft copolymerization, and also radiation-induced reduction of metallic ions. This technique can be used for generating (i) radiation-crosslinked nanogels from synthetic/biopolymers [ 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 ], (ii) conjugated NPs from size-controlled polymer templates through radiation [ 85 , 86 ], (iii) NPs from self-assembly of radiation-induced grafted copolymers [ 87 , 88 ], and (iv) AuNPs-hybrid NPs from radiation-induced reduction [ 89 , 90 , 91 , 92 , 93 , 94 ]. These are summarized in Table 3 .…”

“…Particle size of NPs can be controlled using polymer chain templates. Radiation-controlled polymer-chain templates for controlling particle size of deoxycholic acid functionalized chitosan NPs as a drug nanocarrier was demonstrated [ 85 , 86 ]. Radiation-induced graft copolymerization of stearyl methacrylate (pSMA) or poly(poly(ethylene glycol) monomethacrylate) (pPEGMA), as hydrophobic/hydrophilic polymer brushes on chitosan, have been reported [ 87 , 88 ].…”

pH-Responsive Water-Soluble Chitosan Amphiphilic Core–Shell Nanoparticles: Radiation-Assisted Green Synthesis and Drug-Controlled Release Studies

“…CS exhibits biodegradability [ 16 ], biocompatibility [ 17 ], low toxicity [ 18 ], and functionalization ability. With the amino (–NH 2 ) and hydroxyl (–OH) groups, their functions enable CS to conjugate with several molecules, such as ethylene glycol (PEG) [ 19 , 20 , 21 ], gallic acid [ 22 ], deoxycholic acid [ 23 ], and bombesin peptide [ 24 ]. According to the functional groups, CS also has metal chelation and reduction reaction capacities [ 25 , 26 ], antioxidant/antimicrobial activities [ 27 ], and pH-responsive ability [ 28 ].…”