Caffeine Encapsulation in Metal Organic Framework MIL-53(Al) at Pilot Plant Scale for Preparation of Polyamide Textile Fibers with Cosmetic Properties

Abstract

Currently in the marketplace, we can find clothing items able to release skin-friendly ingredients while wearing them. These innovative products with high-added value are based on microencapsulation technology. In this work, due to its lightness, flexibility, porosity, chemical affinity and adsorption capacity, metal− organic framework (MOF) MIL-53(Al) was the selected microcapsule to be synthesized at a large scale and subsequent caffeine encapsulation. The synthesis conditions (molar ratio of reactants, solvents used, reaction time, temperature, pressure reached in the reactor and activation treatment to enhance the encapsulation capacity) were optimized by screening various scaling-up reactor volumes (from lab-scale of 40 mL to pilot plant production of 3.75 L). Two types of Al salts (Al(NO 3 ) 3 •9H 2 O from the original recipe and Al 2 (SO 4 ) 3 as commercial SUFAL 8.2) were employed. The liporeductor cosmetic caffeine was selected as the active molecule for encapsulation. Caffeine (38 wt %) was incorporated in CAF@ MIL-53(Al) microcapsules, as analyzed by TGA and corroborated by GC/MS and UV−vis after additive extraction. CAF@MIL-53(Al) microcapsules showed a controlled release of caffeine during 6 days at 25 °C (up to 22% of the initial caffeine). These capsules were incorporated through an industrial spinning process (with temperatures up to 260 °C) to manufacture PA-6 fibers with cosmetic properties. Up to 0.7 wt % of capsules were successfully incorporated into the fibers hosting 1700 ppm of caffeine. Fabrics were submitted to scouring, staining, and washing processes, detecting the presence of caffeine in the cosmetic fiber.

Mechanochemical Encapsulation of Caffeine in UiO-66 and UiO-66-NH2 to Obtain Polymeric Composites by Extrusion with Recycled Polyamide 6 or Polylactic Acid Biopolymer

“…The capsules obtained through these procedures usually consist of a polymeric layer that covers the additive. An alternative to these capsules is to encapsulate additives in porous materials, both inorganic (e.g., zeolites [ 15 ]) and organic–inorganic materials (e.g., MOF [ 16 ]). The former allow processing at high temperatures while the latter preserve this property and are more compatible with textiles due to their organic–inorganic nature.…”

“…They exhibit high porosity, high specific surface areas, excellent chemical and thermal stability, and the possibility of varying the pore size, shape, or chemical functionality by modifying the metal cluster and the nature of the linker. This makes them attractive for numerous applications, such as encapsulation [ 16 ], the development of selective membranes for molecular separation [ 17 , 18 ], adsorption and storage of gases [ 19 ], catalysis [ 20 , 21 ], and in biomedicine [ 22 ]. Among various MOF designs, those featuring zirconium-based structures incorporating [Zr 6 O 4 (OH) 4 ] 12+ cluster nodes and carboxylate linkers are highly appealing due to their outstanding chemical and thermal stability.…”

“…Caffeine, known as 1,3,7-trimethylxanthine, is a versatile drug with amphiphilic properties that has gained significant attention in the cosmetic industry due to its anti-cellulite properties. There are studies in the literature in which caffeine is encapsulated in the MOFs [ 16 , 32 , 33 , 34 ] by immersing the previously synthesized MOF in a caffeine solution, which entails a subsequent step of filtration and drying. To improve this process, various advances have been made to limit the steps, such as performing the in situ synthesis of the MOF with caffeine [ 35 , 36 ] or performing pressure encapsulation with the already synthesized MOF [ 37 ].…”

MOF–Thermogel Composites for Differentiated and Sustained Dual Drug Delivery

“…Herein, we report a simple-to-formulate MOF–thermogel platform that capitalizes on the drug encapsulation abilities of both thermogel and MOF components to achieve differentiated dual drug release (Figure ). For this purpose, MOFs [UiO-66, MOF-808, MIL-100­(Fe), and MIL-53­(Al)] that are water-stable, easy to synthesize on large scales, − and possess low cytotoxicity were chosen. To design effective MOF–thermogel composites, it is essential to understand the possible interactions between the MOF and the thermogelling polymer component.…”

The impact of MOFs in pH-dependent drug delivery systems: progress in the last decade

“…Beyond the biomedical field, MOF drug delivery has a variety of industrial applications, including water treatment, catalysis, cosmetics, enzymatic processes, biopreservation, and the creation of additive textiles. 26…”