A green method for the production of an efficient bioimaging nanotool

Abstract

The possibility of exploring basic biological phenomena requires the development of new and efficient bio-imaging tools.

Environmentally Friendly Method of Assembly of Cardanol and Cholesterol into Nanostructures Using a Continuous Flow Microfluidic Device

“…45−47 Pure CA mixed with a minor amount of CH allowed forming stable nanovectors able to vehicle different kinds of molecules that can provide stabilizing, 30 antiproliferative, and antioxidant 48 effects and even function as a fluorescent tool for bioimaging. 49 Here, for the first time, by the usage of MHF devices, we produced nanosized liposomal or micellar systems based on CA, or in combination with CH, substantially confirming the amphiphilic character of this compound, 41,50 particularly in basic media wherein it assumes an ionic character. By increasing the amount of CH in the lipid mixture, a system transition from spherical CA micelles to CA/CH mixed closed vesicles was demonstrated.…”

“…Original system composition and experimental temperatures were chosen following the conventional in-batch method and adjusted accordingly. 49 A stream of organic solvent (IPA) containing the CH/CA mixture (0.6:1 molar ratio, solution 1 of Table S1) and a BB aqueous solution were injected, through programmable syringe pumps, respectively, within the central inlet microchannel and the two side channels. At the microchannels' crossing (i.e., "focusing zone"), the solvent stream was focused into a narrow stream sheathed by the two adjacent flows of aqueous buffer (top picture in Figure 1a).…”

“…This phenomenon was justified by Jahn and co-workers, accounting for a mechanism of disassembly−reassembly of liposomes that move along the channel, undergoing the fluid streamlines, through zones with an alcohol concentration above or below the critical one. 28 Compared to the in-batch approach, 49 the microfluidic route allowed producing size-monodisperse ANSs of different dimensions according to the FRRs, without further postproduction size separation steps required. This proved to be beneficial in the perspective of investigating the influence of several other physico-chemical process variables such as temperature or system composition.…”

“…Operative reasons primarily related to the employment of T and of FRR conditions able to provide sizes lower than 200 nm motivated this choice and this was corroborated by the outcomes provided by the micro-DSC measurements according to which an endothermic peak appears in the temperature range 30−55 °C (see below). Such experimental setting resulted largely being more accessible when compared to the procedure in-batch, 49 which, contrarily to the microfluidic route, requires two 90 °C steps to ensure the optimal solvent-free mixture of the pure components, followed by a 60 °C sonication and centrifugation to separate the smaller nanostructures from the larger ones. Effects of CH.…”

“…Indeed, the hydrophilic–lipophilic balance value, according to the Griffin scale, is around 6 for the hydrogenated form of CA, likely because of the low polarity of the phenolic ring, therefore it is primarily soluble in organic solvents. Several examples in the literature have evidenced the ability of CA: (i) to stabilize phospholipid-based liposome; indeed, low values of the n -octanol–water partition coefficient (log P = 3.54) indicate the favorable hydrophilic–lipophilic balance to accommodate CA molecules into a phospholipid bilayer; (ii) to be chemically engineered, via substitution in the phenolic ring or modification in the reactive hydroxyl group, to develop new breeds of CA-based amphiphiles, − which can be chemically driven to form stable nanoaggregates serving as soft templates for the growth of unique nanomaterials; − or (iii) to form bilayers by itself or in combination with cholesterol (CH). , This latter ability has shown to have a concentration-dependent role in promoting the cohesion of the membrane lipids, to favor a liquid-ordered phase of the membrane, to selectively modulate the fluidity of the membrane in either the polar part or in the hydrophobic region also, and finally to affect the membrane permeability (or the drug release) to solutes. − Pure CA mixed with a minor amount of CH allowed forming stable nanovectors able to vehicle different kinds of molecules that can provide stabilizing, antiproliferative, and antioxidant effects and even function as a fluorescent tool for bioimaging …”