Preparation of sodium fluoride-loaded gelatin microspheres, characterization and cariostatic studies

Abstract

Sodium fluoride-loaded gelatin microspheres (NaF-GMS) were prepared using double-phase emulsified condensation polymerization. The average diameter of microspheres was (11.33+/-5.56) microm. The drug content and encapsulation efficiency were 8.80% and 76.73%, respectively. The fluoride releasing profiles of NaF-GMS in physiological saline and artificial saliva (pH 4.5, pH 6.8) showed that NaF-GMS had a sustained-release property and fluoride release rate was increased in pH 4.5 artificial saliva. Experiments conducted in rabbits' oral cavity using NaF-GMS and NaF solution as control revealed NaF-GMS could maintain oral fluoride retention longer than NaF solution. Cariostatic abilities of NaF-GMS including demineralization prohibition in vitro, fluoride deposition in artificial dental plaque and the ability of targeting to cariogenic bacteria were investigated in artificial dental plaque. The results indicated NaF-GMS with lower fluoride concentrations could achieve equivalent cariostatic effect to the concentrated NaF solution, at the same time, could prolong fluoride retention in dental plaque. Microscopic observation showed that NaF-GMS carrying fusion protein of glucan-binding domain could adhere more bacteria than NaF-GMS and this might indicate the possibility of targeting to cariogenic bacteria when NaF-GMS were properly modified.

Fluoride varnish containing chitosan demonstrated sustained fluoride release

“…The amount of fluoride released from a varnish typically decreases in a few hours and continues to decline for up to 24 h, while the cumulative fluoride ion release increases in the first hour up to 24 h 13) . However, the release of fluoride ions from dental material can be controlled or sustained by encapsulating or coating sodium fluoride particles with either natural polymers or synthetic polymers, such as gelatin 14,15) , ethylcellulose 15) , and polysiloxane 16) .…”

Current Trends in Gelatin-Based Drug Delivery Systems

“…Different synthesis techniques usually have in common the use of chemical crosslinkers that are necessary to tune DDSs’ degradation and drug release kinetics. The most-used crosslinkers are glutaraldehyde (GA) [ 88 , 89 , 90 ], followed by formaldehyde (FA), genipin [ 91 ], dialdehyde carboxymethyl cellulose (DCMC) [ 92 ], methylenebisacrylamide (MBA) [ 93 ], formalin [ 94 ], diisopropylcarbodiimide (DIC) [ 95 ], and calcium chloride (CaCl 2 ) [ 96 , 97 ]. Much less-common are the physical crosslinking by means of heat [ 98 ] and the enzymatic one, mediated by enzymes such as transglutaminase (TG) [ 99 ].…”

“…Different synthesis techniques usually have in common the use of chemical crosslinkers that are necessary to tune DDSs' degradation and drug release kinetics. The most-used crosslinkers are glutaraldehyde (GA) [88][89][90], followed by formaldehyde (FA), genipin [91], dialdehyde carboxymethyl cellulose (DCMC) [92], methylenebisacrylamide (MBA) [93], formalin [94], diisopropylcarbodiimide (DIC) [95], and calcium chloride (CaCl2) As shown by Table 1, in the synthesis of micrometer and nanometer devices, there are no limitations to the nature of the gelatin used, since many studies utilize both Type A and Type B to obtain DDSs with the desired release kinetics of biologically active molecules [76][77][78][79][80]. As regards the gelatin source, gelatin derived from porcine [81][82][83] and bovine skin [84,85] are the most-commonly used.…”