Pickering-Type Water-in-Oil-in-Water Multiple Emulsions toward Multihollow Nanocomposite Microspheres

Abstract

Multihollow hydroxyapatite (HAp)/poly(L-lactic acid) (PLLA) nanocomposite microspheres were readily fabricated by solvent evaporation from a "Pickering-type" water-in-(dichloromethane solution of PLLA)-in-water multiple emulsion stabilized with HAp nanoparticles. The multiple emulsion was stabilized with the aid of PLLA molecules used as a wettability modifier for HAp nanoparticles, although HAp nanoparticles did not work solely as particulate emulsifiers for Pickering-type emulsions consisting of pure dichloromethane and water. The interaction between PLLA and HAp nanoparticles at the oil-water interfaces plays a crucial role toward the preparation of stable multiple emulsion and multihollow microspheres.

Hydroxylapatite nanoparticles: fabrication methods and medical applications

“…By using a water-in-oil-in-water multiple emulsion, multiholow microspheres can also be prepared in the same manner [359]. The HAp-nanoparticle-coated microspheres showed improved cell adhesion and spreading compared with bare biodegradable microspheres [285].…”

Osteoinductive PolyHIPE Foams as Injectable Bone Grafts

“…29 Multiple groups have successfully fabricated and characterized water-in-oil (w/o) Pickering polyHIPEs utilizing both titania and silica nanoparticles. [30][31][32][33] The preferential location of self-assembled particles at the pore wall potentially provides a bioactive component for direct contact with encapsulated MSCs for signaling to promote osteoblast differentiation. Furthermore, this methodology promotes the ability to use less of the expensive bioactive particles and still achieve the desired cellular response due to the presentation of the particles at the polyHIPE pore walls.…”

Stability and rheology of W/Si/W multiple emulsions with polydimethylsiloxane

“…Multiple emulsions can be prepared by either a two-step procedure or a single-step procedure [12][13][14][15][16][17]. Two-step is a common method to prepare double emulsion, in the first step, a primary emulsion (O/W or W/O) is prepared, and in the second step, the primary emulsion (O/W or W/O) is re-emulsified in either an oil solution containing a low HLB surfactant to produce an O/W/O double emulsion or an aqueous solution with a high HLB surfactant to produce a W/O/W double emulsion [12,13].…”

“…Two-step is a common method to prepare double emulsion, in the first step, a primary emulsion (O/W or W/O) is prepared, and in the second step, the primary emulsion (O/W or W/O) is re-emulsified in either an oil solution containing a low HLB surfactant to produce an O/W/O double emulsion or an aqueous solution with a high HLB surfactant to produce a W/O/W double emulsion [12,13]. Single-step has drawn attention recently, which the aqua phase and oil phase including oils, a high HLB surfactant and a low HLB surfactant are emulsified once to prepare a multiple emulsion [14].…”