Novel Developments on Stimuli-Responsive Probiotic Encapsulates: From Smart Hydrogels to Nanostructured Platforms

Abstract

Biomaterials engineering and biotechnology have advanced significantly towards probiotic encapsulation with encouraging results in assuring sufficient bioactivity. However, some major challenges remain to be addressed, and these include maintaining stability in different compartments of the gastrointestinal tract (GIT), favoring adhesion only at the site of action, and increasing residence times. An alternative to addressing such challenges is to manufacture encapsulates with stimuli-responsive polymers, such that controlled release is achievable by incorporating moieties that respond to chemical and physical stimuli present along the GIT. This review highlights, therefore, such emerging delivery matrices going from a comprehensive description of addressable stimuli in each GIT compartment to novel synthesis and functionalization techniques to currently employed materials used for probiotic’s encapsulation and achieving multi-modal delivery and multi-stimuli responses. Next, we explored the routes for encapsulates design to enhance their performance in terms of degradation kinetics, adsorption, and mucus and gut microbiome interactions. Finally, we present the clinical perspectives of implementing novel probiotics and the challenges to assure scalability and cost-effectiveness, prerequisites for an eventual niche market penetration.

Probiotics: mechanism of action, health benefits and their application in food industries

“…The unique biological and physicochemical characteristics of nanocapsules, such as smaller particle sizes, higher surface areas, and increased reactivities, improve the efficiency of encapsulated probiotics, thus, providing a logical solution to human health and safety ( Singh et al, 2022 ). The ability of nanoencapsulation to entrap probiotics is analyzed by the potential of electrospun nanofibers, hydrogels, nanocoating, nanoliposomes, and other nanomaterials ( Garcia-Brand et al, 2022 ).…”

Hydrogels as promising carriers for the delivery of food bioactive ingredients

“…According to the Food and Agriculture Organization-World Health Organization (FAO-WHO), the minimum level of probiotics should be 10 7 CFU/g to achieve desired therapeutic effects ( 120 , 121 ). In the process of passing through the gastrointestinal tract, probiotics not only suffer from the catalytic action of gastric enzymes and the harsh acidic environment of the stomach, but also resist the antibacterial activity of intestinal bile salts and the action of protease, which puts forward high requirements for probiotics to reach the intestinal tract in a certain number ( 122 , 123 ). Hydrogels can provide the protection for probiotics, and compared with the hydrogels sourced from single component, hydrogels with multicomponent materials as carrier of probiotics can enable higher concentrations of probiotics to reach specific locations under the same initial concentration, which means it can provide better protection for probiotics ( 124 – 126 ).…”

Research advances on encapsulation of probiotics with nanomaterials and their repair mechanisms on intestinal barriers

“…In order to overcome the adverse conditions mentioned above, some technologies about surface modification and encapsulation of probiotics are developed [28,29]. In which, encapsulation with nanomaterials has attracted more attention due to its advantages, such as stimulus responsibility, multimodal controlled release and high mechanical performance [30,31]. At present, most researches are focused on encapsulation technology to improve probiotics' gastrointestinal tolerance, survival rate and bioactivity [32,33].…”