Hydrogels (HG) are 3D network of hydrophilic macromolecules linked by different "cross-linking points", which have as main advantage their capacity for the adsorption of large amounts of water without any apparent dissolution due to cross-linking. Thus, the hydrogels can undergo reversible swelling-shrinking process upon the modification of the environmental conditions (pH, ionic strength or temperature). This stimuli-responsiveness and their ability to entrap in their interior different types of molecules makes of them suitable platforms for drug delivery applications. Furthermore, HGs exhibit certain similarities to the extracellular tissue matrix and can be used as a support for cell proliferation and migration.
The interest of the interaction between biological systems and hydrogels in different applications has stimulated the interest for designing hydrogels with a homogeneous nanometric size that can be distributed within different organ and tissue, and used for drug delivery or biosensing. This work proposes to take advantage of the inner cavity of liposomes for fabricating hyaluronic acid hydrogel nanoparticles with a well-controlled size. For this purpose, liposomes obtained using the reverse phase [1,2] technique where loaded with hyaluronic acid molecules which then undergo a cross-linking to
form a hydrogel matrix with a well-controlled size define by the dimensions of the inner core of the template liposome (Figure 1). This makes possible to fabricate either liposomes-coated or nude hydrogel nanoparticles which may be exploited in different technological fields including cosmetic,
ophthalmology (dry eye disease treatment) or food science.