Gellan gum microspheres crosslinked with trivalent ion: effect of polymer and crosslinker concentrations on drug release and mucoadhesive properties

Abstract

Gellan gum microspheres were obtained by ionotropic gelation technique, using the trivalent ion Al(3+). The percentage of entrapment efficiency ranged from 48.76 to 87.52% and 2(2) randomized full factorial design demonstrated that both the increase of polymer concentration and the decrease of crosslinker concentration presented a positive effect in the amount of encapsulated drug. Microspheres size and circularity ranged from 700.17 to 938.32 μm and from 0.641 to 0.796 μm, respectively. The increase of polymer concentration (1-2%) and crosslinker concentration (3-5%) led to the enlargement of particle size and circularity. However, the association of increased crosslinker concentration and reduced polymer content made the particles more irregular. In vitro and ex vivo tests evidenced the high mucoadhesiveness of microspheres. The high liquid uptake ability of the microspheres was demonstrated and the pH variation did not affect this parameter. Drug release was pH dependent, with low release rates in acid pH (42.40% and 44.93%) and a burst effect in phosphate buffer pH (7.4). The Weibull model had the best correlation with the drug release data, demonstrating that the release process was driven by a complex mechanism involving the erosion and swelling of the matrix or by non-Fickian diffusion.

Mucoadhesive nanostructured polyelectrolytes complexes modulate the intestinal permeability of methotrexate

“…The positive surface charges of nanoparticles can favour the adhesion to the anionic mucus layer of intestine, prolonging the residence time in the target site and making closer the contact with biological membrane (Asane et al, 2008;Boni et al, 2016;Gamboa and Leong, 2013). After the nanocarriers mucoadhesion, whether the accumulation in target cells or the permeation through the intestinal membrane will be the prevalent process is what will determine the extension of local or systemic action.…”

Gellan Gum-based luminal fillers for peripheral nerve regeneration: anin vivostudy in the rat sciatic nerve repair model

“…However, GG has already shown great potential for other regenerative applications, such as dentistry, 23 fibrocartilage tissue engineering, 24 wound healing 25 or bone regeneration, 26 as well as in the area of drug delivery. 27,28 After the production of different GG formulations, the hydrogels were subjected to a physicochemical characterization and in vitro preliminary assessment using immortalized Schwann cells. Subsequently, the formulations were injected into chitosan nerve guidance conduits, freeze-dried and implanted in vivo for different periods of observation time.…”

Recent advances in smart hydrogels for biomedical applications: From self-assembly to functional approaches

“…Then, when temperature decreases, the chains adopt a double-helical conformation with ordered junction zones, resulting in a three-dimensional network. These characteristics make GG an interesting material for pharmaceutical applications [49,[60][61][62][63][64].…”