Polymer Capsules for Enzymatic Catalysis in Confined Environments

Abstract

Catalysis is at the base of a series of biological and technological application processes. In recent years, the tendency has developed to carry out catalyzed reactions within confined structures, thus forming systems called micro or nanoreactors. Compartmentalized structures are cavities delimited by a wall where specific functions are introduced with a defined concentration and in the desired sites. These containers are generally referred to as nano or microcapsules, assuming the function of reactors in the presence of chemical reactions. Among the various types of existing structures, one of the most interesting is represented by systems made with polymers. This review aims to highlight some of the current advances in the use of functionalized structures that are useful for catalysis reactions, paying particular attention to polymer capsules and enzymes. The built-up methods used for the production of polymer capsules, as well as the aspects that influence membrane permeability and reactivity to environmental conditions, are discussed. Recent advances on biocatalysis confined in polymeric capsules are illustrated, and the strengths and weaknesses of the principal nanoreactors are considered.

Optimizing the Preparation of Semi-Crystalline Paraffin/Poly(Urea-Formaldehyde) Microcapsules for Thermal Energy Storage

“…The melting enthalpy increased to 110.0 J/g with the addition of 0.25 wt% crosslinker, which was an improvement of 63% when compared to microcapsules prepared without crosslinker. The enthalpy value further rose with more crosslinker and achieved 137.0 J/g at crosslinker addition amount of 1 wt%, which is a rather high value when compared to the literature [25,26]. The DSC curves of samples are presented in Figure 9.…”

“…Gaitzsch et al summed up the methods of fabricating and designing confined microenvironments and the relevant applications after the first publications of Discher and Eisenberg on polymer vesicles [24]. Cuomo et al focused on the preparation and designation of compartmentalized spaces as nanoreactor which could be used in biological and technical aspects [25]. Preparation and influencing factors of paraffin/poly(urea-formaldehyde) (PUF) microcapsules by in-situ polymerization have been investigated by many researchers [26].…”

Bottom-Up Construction of Complex Biomolecular Systems With Cell-Free Synthetic Biology

“…Other types of membrane compartments have also been used for cell-free protein expression, such as polymersomes, proteinbased membranes, and polymeric shells (Figure 4E). Although there exist many different strategies and materials to make capsules (Cuomo et al, 2019), the conditions necessary for their production often prevent encapsulating cell-free systems. Martino et al (2012) used a microfluidic capillary device to generate template double-emulsion for the direct encapsulation of a cell-free expression system inside polymersomes composed of PEG-b-PLA copolymer and PLA homopolymer to increase their stability.…”

Enhanced Curcumin Bioavailability through Nonionic Surfactant/Caseinate Mixed Nanoemulsions

“…Furthermore, these downsides may be overcome by encapsulating curcumin within food‐grade delivery systems such as liposomes (Chen et al., ), nanocomplexes (Chen, Li, & Tang, ), colloidosomes (Shah et al., ), emulsions (Aditya et al., ; Sari et al., ), nanoemulsions (Ahmed, Li, McClements, & Xiao, ; Patel & Velikov, ), or biopolymer nanoparticles (Hu et al., ; Xiao, Nian, & Huang, ). Among these strategies based on colloidal suspension for encapsulation and protection of compounds, the utilization of emulsions represents a good compromise to overcome the limits mentioned above (Cuomo et al., ; Cuomo, Ceglie, De Leonardis, & Lopez, ; Mosca, Murgia, Ceglie, Monduzzi, & Ambrosone, ). Nanoemulsions, in particular, are fine dispersions of oil droplet in water (Gurpreet & Singh, ) and are rapidly digested in the intestinal tract, thus, if the oil phase contains hydrophobic nutraceuticals, nanoemulsions can increase their bioavailability.…”