Retinyl palmitate polymeric nanocapsules as carriers of bioactives

Abstract

Nanocapsules containing poly(d,l-lactide) shell and retinyl palmitate core have been prepared by the pre-formed polymer interfacial deposition method. Dynamic light scattering measurements yielded an average hydrodynamic diameter of ∼220nm and a polydispersity index of ∼0.12. Small-angle neutron scattering experiments revealed the presence of two populations of nanocapsules of core diameters ∼192 and 65nm. Freeze fracture transmission electron microscopy showed a polydisperse population of nanocapsules (NC), with a poly(d,l-lactide) shell thickness between 11 and 3nm. For comparison purposes, nanoemulsions (NE, no polymer) and nanospheres (NS, polymer matrix) were also prepared. Each type of nanoparticles exhibited a different morphology (when examined by electron microscopy), in particular NC showed deformability by capillary adhesion. All three types of nanoparticles successfully encapsulated the poorly water-soluble molecules baicalein and benzophenone-3. The thermal behavior of the various nanoparticles was different to a physical mixture of its individual components. Cytotoxicity and phototoxicity assays, performed in human keratinocytes (HaCaT) and murine fibroblasts (BALB/c 3T3), showed that the NC were only cytotoxic at high concentrations. In vitro release studies of benzophenone-3, by the dialysis bag method using NC and NS, showed a sustained release; however, permeation studies using plastic surgery human abdominal skin in Franz diffusion cells showed that a higher amount of benzophenone-3 from NC penetrated into the skin, most probably due to the deformable nature of these nanoparticles.

Encapsulation of Vitamins A and E as Spray-Dried Additives for the Feed Industry

“…Peak temperature (T p ) and enthalpy values (∆h) of the main endothermic events in the first heating scan. Pure vitamin A (VA) revealed a sharp endotherm transition from −10 to 5 • C attributed to the melting of the crystallized oils, while vitamin E (VE) showed a flat thermogram (Figure 3a), according to the literature [72,73]. The maltodextrin (MD) and Capsul ® (CAP) are starch-derived materials, and their typical endothermic peak attributed to the gelatinization of starch, which depends on the heating rate and the origin and structure order of the starch [74].…”

Vesicular systems for dermal and transdermal drug delivery

“…Literature reports the wide use of poly (3-caprolactones) and poly (D, L-lactides) for dermal applications of nanocapsules. [53][54][55] The core is generally made of triglycerides with the dispersed drug. It is also possible to nd sorbitan monostearate, or even other additives providing an intrinsic effect (turmeric oil for its antibacterial and antioxidant action, for example).…”

Improving drug biological effects by encapsulation into polymeric nanocapsules

“…Breast cancer cells were used to evaluate PLGA‐nanocapsules and allyl‐functionalized cationic PLA‐nanocapsules, prostate cancer cells were used to evaluate allyl‐functionalized cationic‐PLA‐nanocapsules, myeloid leukemia cells were used to evaluate PCL‐nanocapsules, fibroblasts were used to evaluate PLA‐nanocapsules and keratinocytes were used to evaluate PLA‐nanocapsules . No considerable cytotoxicity was observed except for PLGA‐nanocapsules .…”

“…To predict dermal safety of polymeric nanocapsules composed of PLA, sorbitan monostearate and retinyl palmitate coated with Pluronic F68, cytotoxicity and phototoxicity assays were conducted using human keratinocyte cell line (HaCaT) and murine BALB/c 3T3 fibroblasts under UVA irradiation . The nanocapsules showed cytotoxicity only at high concentrations and elevated phototoxic potential in BALB/c 3T3 fibroblasts, most likely due to the presence of retinyl palmitate.…”