Saccharomyces cervisiae as an Efficient Carrier for Delivery of Bioactives: a Review

Yeast glucan particles: An express train for oral targeted drug delivery systems

As an emerging drug delivery vehicle, yeast glucan particles (YGPs) derived from yeast cells could be specifically taken up by macrophages. Therefore, these vehicles could rely on the recruitment of macrophages at the site of inflammation and tumors to enable targeted imaging and drug delivery. This review summarizes recent advances in the application of YGPs in oral targeted delivery systems, covering the basic structure of yeast cells, methods for pre-preparation, drug encapsulation and characterization. The mechanism and validation of the target recognition interaction of YGPs with macrophages are highlighted, and some inspiring cases are presented to show that yeast cells have promising applications. The future chances and difficulties that YGPs will confront are also emphasized throughout this essay. YGPs are not only the "armor" but also the "compass" of drugs in the process of targeted drug transport. This system is expected to provide a new idea about the oral targeted delivery of anti-inflammatory and anti-tumor drugs, and furthermore offer an effective delivery strategy for targeted therapy of other macrophage-related diseases.

Bioinspired yeast-based β-glucan system for oral drug delivery

Oral drug delivery is the preferred route of drug administration for patients, especially those who need long-term medication. Recently, bioinspired drug delivery systems have emerged for the oral delivery of various therapeutics. Among them, the yeast-based β-glucan system is a novel and promising platform, for oral administration that can overcome the biological barriers of the harsh gastrointestinal environment. Remarkably, the yeast-based β-glucan system not only protects the drug through the harsh gastrointestinal environment but also achieves targeted therapeutic effects by specifically recognizing immune cells, especially macrophages. Otherwise, it exhibits immunomodulatory properties. Based on the pleasant characteristics of the yeast-based β-glucan system, they are widely used in various macrophage-related diseases for oral administration. In this review, we introduced the structure and function of yeast-based β-glucan. Subsequently, we further summarized the current preparation methods of yeast-based β-glucan carriers and the strategies for preparing yeast-based β-glucan drug delivery systems. In addition, we focus on discussing the applications of β-glucan drug delivery systems in various diseases. Finally, the current challenges and future perspectives of the β-glucan drug delivery system are introduced.

"Dual sensitive supramolecular curcumin nanoparticles" in "advanced yeast particles" mediate macrophage reprogramming, ROS scavenging and inflammation resolution for ulcerative colitis treatment

Ulcerative colitis (UC) faces some barriers in oral therapy, such as how to safely deliver drugs to the colon and accumulate in the colon lesions. Hence, we report an advanced yeast particles system loaded with supramolecular nanoparticles with ROS scavenger (curcumin) to treat UC by reducing oxidative stress state and inflammatory response and accelerating the reprogramming of macrophages. In this study, the dual-sensitive materials are bonded on β-cyclodextrin (β-CD), the D-mannose (Man) is modified to adamantane (ADA), and then loaded with curcumin (CUR), to form a functional supramolecular nano-delivery system (Man-CUR NPs) through the host-guest interaction. To improve gastrointestinal stability and colonic accumulation of Man-CUR NPs, yeast cell wall microparticles (YPs) encapsulated Man-CUR NPs to form Man-CUR NYPs via electrostatic adsorption and vacuum extrusion technologies. As expected, the YPs showed the strong stability in complex gastrointestinal environment. In addition, the Man modified supramolecular nanoparticles demonstrated excellent targeting ability to macrophages in the in vitro cellular uptake study and the pH/ROS sensitive effect of Man-CUR NPs was confirmed by the pH/ROS-dual stimulation evaluation. They also enhanced lipopolysaccharide (LPS)-induced inflammatory model in macrophages through downregulation of pro-inflammatory factors, upregulation of anti-inflammatory factors, M2 macrophage polarization, and scavenging the excess ROS. Notably, in DSS-induced mice colitis model, Man-CUR NYPs can reduce the inflammatory responses by modulating TLR4/NF-κB signaling pathways, alleviate oxidative stress by Nrf2/HO-1 signaling pathway, promote macrophages reprogramming and improve the favorable recovery of the damaged colonic tissue. Taken together, this study not only provides strategy for "supramolecular curcumin nanoparticles with pH/ROS sensitive and multistage therapeutic effects" in "advanced yeast particles", but also provided strong theoretical support multi-effect therapy for UC.

Potential Application of Yeast Cell Wall Biopolymers as Probiotic Encapsulants

Biopolymers of yeast cell walls, such as β-glucan, mannoprotein, and chitin, may serve as viable encapsulants for probiotics. Due to its thermal stability, β-glucan is a suitable cryoprotectant for probiotic microorganisms during freeze-drying. Mannoprotein has been shown to increase the adhesion of probiotic microorganisms to intestinal epithelial cells. Typically, chitin is utilized in the form of its derivatives, particularly chitosan, which is derived via deacetylation. Brewery waste has shown potential as a source of β-glucan that can be optimally extracted through thermolysis and sonication to yield up to 14% β-glucan, which can then be processed with protease and spray drying to achieve utmost purity. While laminarinase and sodium deodecyle sulfate were used to isolate and extract mannoproteins and glucanase was used to purify them, hexadecyltrimethylammonium bromide precipitation was used to improve the amount of purified mannoproteins to 7.25 percent. The maximum chitin yield of 2.4% was attained by continuing the acid-alkali reaction procedure, which was then followed by dialysis and lyophilization. Separation and purification of yeast cell wall biopolymers via diethylaminoethyl (DEAE) anion exchange chromatography can be used to increase the purity of β-glucan, whose purity in turn can also be increased using concanavalin-A chromatography based on the glucan/mannan ratio. In the meantime, mannoproteins can be purified via affinity chromatography that can be combined with zymolase treatment. Then, dialysis can be continued to obtain chitin with high purity. β-glucans, mannoproteins, and chitosan-derived yeast cell walls have been shown to promote the survival of probiotic microorganisms in the digestive tract. In addition, the prebiotic activity of β-glucans and mannoproteins can combine with microorganisms to form synbiotics.

The application of natural product-delivering micro/nano systems in the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a type of recurrent intestinal diseases. Natural product molecules have been gradually developed into an important source of anti-inflammatory drugs for treating IBD owing to their high anti-inflammatory activity, well known safety, structural specificity and therapeutic mechanism diversity. However, most of the natural products are restricted by poor solubility in actual application. How to achieve satisfactory bioavailability during the treatment of IBD is one of the urgent problems to be solved in the current research. Micro/nano drug delivery systems could improve the solubility of drugs with targeted delivery of anti-inflammatory drugs to the colon with responsive release property. Therefore, using micro/nano drug delivery systems, the problems mentioned above involving natural product molecules in the treatment of IBD could be solved. According to the compositions of the intestinal tract and inflammatory characteristics of IBD, the strategies of using micro/nano drug delivery systems for natural products could be summarized in two steps: targeted delivery and responsive release. In this review, the targeted and responsive release strategies of the micro/nano drug delivery systems combined with their anti-inflammatory effects in IBD animal models to illustrate that the proposed strategies could be potential treatments for symptomatic IBD are described.

How far have we explored fungi to fight cancer?

The use of fungal cultures have been well documented in human history. Although its used in healthcare, like penicillin and statins, have saved countless of lives, but there is still no fungal products that are specifically indicated for cancers. Research into fungal-derived materials to curb cancers in the recent decades have made a considerable progress in terms of drug delivery vehicles, anticancer active ingredients and cancer immunotherapy. Various parts of the organisms have successfully been exploited to achieve specific tasks. Apart from the identification of novel anticancer compound from fungi, its native capsular structure can also be used as drug cargo to achieve higher oral bioavailability. This review summarises the anticancer potential of fungal-derived materials, highlighting the role of capsular polysaccharides, proteins, and other structures in variety of innovative utilities to fit the current pharmaceutical technology. Many bioactive compounds isolated from fungi have also been formulated into nanoparticles to achieve greater anticancer activity. The progress of fungal compounds and their analogues in clinical trials is also highlighted. In addition, the potential of various fungal species to be developed for anticancer immunotherapy are also discussed.

Efficient encapsulation of curcumin into spent brewer's yeast using a pH-driven method

Curcumin (CUR) was encapsulated into yeast cells (YCs) through a pH-driven method with a 5.04-fold increase in loading capacity and a 43.63-fold reduction in incubation time compared to the conventional diffusion method. Optimal encapsulation was obtained when the mass ratio of CUR to YCs was 0.1, and the loading capacity and encapsulation efficiency were 8.07% and 80.66%, respectively. Encapsulation of CUR into YCs was confirmed by fluorescence microscopy, differential scanning calorimetry, and thermogravimetric analysis. Fourier transform infrared spectroscopy and X-ray diffraction further demonstrated that the encapsulated CUR was interacted with mannoprotein and β-glucan of the cell wall network through hydrophobic interaction and hydrogen bond in amorphous state. The in vitro bioaccessibility of YCs-loaded CUR was significantly increased by 6.05-fold. The enhanced encapsulation efficiency and rapid encapsulation process proposed in this study could facilitate YCs-based microcarriers to encapsulate bioactive substances with higher bioaccessibility.

β-1,3-d-Glucan based yeast cell wall system loaded emodin with dual-targeting layers for ulcerative colitis treatment

Herein, a β-1,3-d-glucan based microcarrier, yeast cell wall microparticles (YPs), was used to develop a food-source-based nano-in-micro oral delivery system for ulcerative colitis (UC) treatment. Briefly, lactoferrin (Lf), which targets intestinal epithelial cells, was used to encapsulate emodin (EMO) to form nanoparticles (EMO-NPs), and then loaded into YPs with the natural macrophages targeting ability, forming a final formula with two outer-inner targeting layers (EMO-NYPs). These dual-targeting strategy could enhance the dual-effects of EMO in anti-inflammatory and mucosal repair effects respectively. As expected, cell uptake assessment confirmed that EMO-NPs and EMO-NYPs could target on the Lf and dection-1 receptors on the membranes of Caco-2 cells and macrophages, respectively. Importantly, EMO-NYPs showed the best anti-UC effects compared to EMO-NPs and free EMO, by inhibiting NF-κB pathway to anti-inflammation and promoting intestinal mucosa repair via MLCK/pMLC2 pathway. The results show that EMO-NYPs are a promising food-based oral delivery system in anti-UC.

Entrapment of Macrophage-Target Nanoparticles by Yeast Microparticles for Rhein Delivery in Ulcerative Colitis Treatment

In this study, we developed an advanced colitis-targeted nanoparticles (NPs)-into-yeast cell wall microparticles (YPs) drug delivery system for ulcerative colitis (UC) therapy. In brief, YPs entrap hyaluronic acid (HA), and polyethylenimine (PEI) modified rhein (RH)-loaded ovalbumin NPs (HA/PEI-RH NPs) to form HA/PEI-RH NYPs. YPs can make HA/PEI-RH NPs pass through gastric environment stably and be degraded by β-glucanase to promote drug release from HA/PEI-RH NYPs in the colon. Cellular uptake evaluation confirmed that HA/PEI-RH NPs could specifically target and enhance the uptake rate via HA ligands. In biodistribution studies, HA/PEI-RH NYPs were able to efficiently accumulate in the inflammed colon in mice. In vivo experiments revealed that the HA/PEI-RH NYPs could significantly alleviate inflammation by inhibiting the TLR4/MyD88/NF-κB signaling pathway. Therefore, HA/PEI-RH NYPs have advantages of good gastric stability, β-glucanase-sensitive release ability, macrophage-targeted ability, and anti-UC effects. These advantages indicate YPs-entrapped multifunctional NPs are a promising oral drug delivery system for UC therapy.

Yeast cells for encapsulation of bioactive compounds in food products: A review

Nowadays bioactive compounds have gained great attention in food and drug industries owing to their health aspects as well as antimicrobial and antioxidant attributes. Nevertheless, their bioavailability, bioactivity, and stability can be affected in different conditions and during storage. In addition, some bioactive compounds have undesirable flavor that restrict their application especially at high dosage in food products. Therefore, food industry needs to find novel techniques to overcome these problems. Microencapsulation is a technique, which can fulfill the mentioned requirements. Also, there are many wall materials for use in encapsulation procedure such as proteins, carbohydrates, lipids, and various kinds of polymers. The utilization of food-grade and safe carriers have attracted great interest for encapsulation of food ingredients. Yeast cells are known as a novel carrier for microencapsulation of bioactive compounds with benefits such as controlled release, protection of core substances without a significant effect on sensory properties of food products. Saccharomyces cerevisiae was abundantly used as a suitable carrier for food ingredients. Whole cells as well as cell particles like cell wall and plasma membrane can act as a wall material in encapsulation process. Compared to other wall materials, yeast cells are biodegradable, have better protection for bioactive compounds and the process of microencapsulation by them is relatively simple. The encapsulation efficiency can be improved by applying some pretreatments of yeast cells. In this article, the potential application of yeast cells as an encapsulating material for encapsulation of bioactive compounds is reviewed.

Maillard conjugates from spent brewer's yeast by-product as an innovative encapsulating material

Yeast-based by-products are greatly available, have a rich nutritional composition and functional properties. The spent brewer's yeast (SBY) cells after enzymatic hydrolysis may be a sustainable and low-cost alternative as carrier material for encapsulation processes by spray drying. Our work had as main purpose to characterise the hydrolysed SBY cell debris after the Maillard reaction and to study their potential as a microencapsulation wall material. SBY-based Maillard reaction products (MRPs) were used to encapsulate ascorbic acid (AA) by spray drying. The Maillard Reaction was able to improve the solubility of solids and proteins by 15% and promoted brown color development (230% higher Browning Index). SBY-based MRPs resulted in particles of a high encapsulation yield of AA (101.90 ± 5.5%), a moisture content of about 3.4%, water activity of 0.15, hygroscopicity values ranging from 13.8 to 19.3 g_H2O/100 g and a glass transition temperature around 71 °C. The shape and microstructure of the produced particles were confirmed by scanning electron microscopy (MEV), indicating very similar structure for control and AA encapsulated particles. Fourier Transform Infrared Spectroscopy (FT-IR) results confirmed the presence of yeast cell debris in the surface of particles. Ascorbic acid was successfully encapsulated in Maillard conjugates of hydrolyzsd yeast cell debris of Saccharomyces pastorianus and maltodextrin as confirmed by optical microscopy, differential scanning calorimetry, MEV and FT-IR.