Hollow Colloidosomes Prepared Using Accelerated Solvent Evaporation

Abstract

We demonstrate a new, scalable, simple, and generally applicable two-step method to prepare hollow colloidosomes. First, a high volume fraction oil-in-water emulsion was prepared. The oil phase consisted of CH2Cl2 containing a hydrophobic structural polymer, such as polycaprolactone (PCL) or polystyrene (PS), which was fed into the water phase. The water phase contained poly(vinylalcohol), poly(N-isopropylacrylamide), or a range of cationic graft copolymer surfactants. The emulsion was rotary evaporated to rapidly remove CH2Cl2. This caused precipitation of PCL or PS particles which became kinetically trapped at the periphery of the droplets and formed the shell of the hollow colloidosomes. Interestingly, the PCL colloidosomes were birefringent. The colloidosome yield increased and the polydispersity decreased when the preparation scale was increased. One example colloidosome system consisted of hollow PCL colloidosomes stabilized by PVA. This system should have potential biomaterial applications due to the known biocompatibility of PCL and PVA.

Food-grade micro-encapsulation systems that may induce satiety via delayed lipolysis: A review

“…The DCM dissolves in water, leading to precipitation of the PLA on the tetradecane droplets. Also polycaprolactone or polystyrene (Shahidan et al 2013) and poly(lactic-coglycolic acid)-based Hemar 2009). Spray drying will result in a high quality product when the heat and mass transfer processes are well controlled, which in general is very well feasible.…”

Colloidosomes: Synthesis, properties and applications

“…Moreover, increasing the particle concentration from 2 to 3 wt % produced visibly less porous colloidosomes as judged by SEM. A slightly different approach was described by Shahidan et al 51 Here either poly( -caprolactone) or polystyrene was precipitated onto a polymeric surfactant-stabilized dichloromethane-in-water emulsion, forming a particle shell during dichloromethane evaporation. One advantage of this strategy is that the colloidosome cores fill up with water after all the dichloromethane is evaporated, thus directly producing a w/w colloidosome without requiring centrifugal transfer.…”

The Formulation Parameter Influence on PHB Hollow Colloidosomes Formation Prepared via Two Step Solvent Evaporation Method

“…The formulation for PHB colloidosomes started from the optimized PCL(1.5)/PVA13k(1.2) system (Entry 1 in Table 1) reported in previous study by Shahidanet al [8]. Fig.1 shows that PHB has the potential to be prepared as colloidosomes.…”

“…The work on colloidosomes was first reported by Velev and colleagues in 1996 [2] although the term was introduced later by Dinsmore et al [1].This hollow particle plays significant roles in microencapsulation: a process in microscopic formation of thin coatings of wall material around an active ingredient [3] This process has been used in varies applications such as controlled release of drugs [4], aroma [5], food industries [6] and protection of biologically active species [7]. Microcapsules preparation methods can takes several steps which might be complex, time consuming and in need of binders [1,8]. A study by Thompson et al [9] reported that latex colloidosomes prepared via thermal annealing might be unfavorable to thermal sensitive active ingredient such as fragrances or drugs.…”