Hydroxypropyl Guar−Borate Interactions with Tear Film Mucin and Lysozyme

Abstract

The interactions of hydroxypropyl guar (HPG) with boric acid, lysozyme, and mucin were characterized by rheology, light scattering, electrophoresis, and isothermal titration calorimetry to help understand how HPG interacts with tear film components. Borate binds to guar under pH, temperature, and ionic strength conditions representative of those found in the eye. The HPG-borate complexes behave as anionic polyelectrolytes and thus interact with cationic lysozyme, a major tear film protein, whereas HPG-borate does not appear to bind to mucin, an anionic glycoprotein. The interactions of HPG, borate, lysozyme, and mucin can be explained by two physical interactions: (1) pH-dependent binding of borate to carbohydrates and (2) the electrostatic attraction of oppositely charged macromolecules.

Advances in Mucoadhesion and Mucoadhesive Polymers

“…[60] However, the majority of studies evaluating mucoadhesive interactions have reported the use of commercially-available lyophilized porcine gastric mucin [51,57,58,[61][62][63][64] and bovine submaxillary gland mucin. [17,[65][66][67] Although, these products may differ from the native mucins they often show less batch-to-batch variability and give more reproducible results.…”

Properties of hydroxypropyl guar/TEMPO-oxidized cellulose nanofibrils composite films

“…It has better water solubility and film forming property than guar gum (Lu et al 2005;Xiao et al 2003) and plays a large role in the various products of chemically modified guar gum (Cheng et al 2002). HPG has been widely used in many industries such as oil recovery, food industry, paints and the formulation of cartridge explosives (Wu et al 2010;Xiao et al 2003).…”

Silver nanoparticles-containing dual-function hydrogels based on a guar gum-sodium borohydride system

“…This can be attributed to the dynamic transition between B(OH) 4 − and B(OH) 3 upon the pH variation: B(OH) 4 − is an effective crosslinking agent for GG, while B(OH) 3 is not; B(OH) 4 − was converted to B(OH) 3 upon the addition of a HCl solution, causing the disintegration of hydrogels; conversely, with the addition of NaOH, B(OH) 4 − was formed, thus, the hydrogels were recovered. Lu et al 28 reported in their study of hydroxypropyl guar (HPG)-borate interactions that the interactions between HPG and borate was sensitive to pH. The sol-gel transition also occurred during the heating/cooling process: the hydrogel became liquid when heated to 70 °C, while the hydrogel was re-formed after cooled down to 20 °C (Fig.…”