In-situ fermentation with gellan gum adding to produce bacterial cellulose from traditional Chinese medicinal herb residues hydrolysate

Probiotic-fermented traditional Chinese herbal medicine, a promising approach to maintaining the intestinal microecology

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese herbal medicines (TCHM) have been extensively used in China and other East and Southeast Asian countries. Due to the low content of bioactive components in most TCHM and the potential toxicity of some herbal ingredients to humans, researchers have turned to probiotic fermentation to enhance the efficacy, mitigate the toxic or side effects and improve the taste of TCHM. Both probiotics and certain TCHM benefit the intestinal microbiota and intestinal barrier of human body, demonstrating synergistic effects on in intestinal microecology.

AIM OF THE STUDY

This review aims to provide an overview of the development of fermentation technology, commonly used probiotic strains for TCHM fermentation, the advantages of probiotic fermentation and the challenges and limitations of probiotic-fermented TCHM. Additionally, it summarises and discusses the impact of probiotic-fermented TCHM on the intestinal barrier and microbiota, as well as the possible mechanisms involved.

MATERIALS AND METHODS

An extensive search of primary literature was conducted using various databases including PubMed, Google Scholar, Web of Science, Elsevier, SpringerLink, ScienceDirect, CNKI, and others. All the plant names have been checked with World Flora Online (http://www.worldfloraonline.org) on August 7, 2024.

RESULTS

The literature mentioned above was analyzed and summarized comprehensively. Probiotic-fermented TCHM can improve the intestinal barrier, modulate gut microbiota, and maintain homeostasis of the intestinal microecology. Modulating intestinal microecology by probiotic-fermented TCHM may be a crucial mechanism for its beneficial effects.

CONCLUSIONS

This article establishes a theoretical basis for further research on the relationship between probiotic-fermented TCHM and the intestinal microecology, with the hope of inspiring innovative concepts for the development of TCHM and exploring the potential of probiotic-fermented TCHM as a promising strategy for maintaining intestinal microecological balance.

Production, structure, and performance of guar gum based bacterial cellulose generated from soy sauce residue hydrolysate by in-situ fermentation

Guar gum based bacterial cellulose (GG-BC) was generated from the soy sauce residue hydrolysate by in-situ fermentation, and its structure and performance were learned systematically. The GG concentration of 0.2 % was most suitable for GG-BC production with the yield of 1.21 g/L. During the in-situ fermentation, GG was implanted into the nano network of BC and thus altered its microstructure and properties. According to the FT-IR and NMR results, GG-BC had similar functional group structure and cellulose structural framework to those of BC. The degree of polymerization (DP) of GG-BC was 526.32-832.16, which was higher than that (426.32) of BC. Also, the GG-BC with low GG addition (0.2 % and 0.4 %) had a higher crystallinity than BC. Moreover, the GG-BC had a better heat tolerance than BC based on its higher temperature reaching the maximum degradation rate. The GG-BC with suitable GG addition had better texture characteristics, UV barrier property, swelling rate, and antioxidant activity than those of BC, showing that the in-situ fermentation with GG addition could promote the performance of GG-BC. Overall, this study can provide an attractive technology for both solving the environmental issue brought by soy sauce residue and producing high value-added GG-BC with good performance efficiently.

Cellulose Based Nano-Scaffolds for Targeted Cancer Therapies: Current Status and Future Perspective

In the last few years, cellulose has garnered much interest for its application in drug delivery, especially in cancer therapy. It has special properties like biocompatibility, biodegradability, high porosity, and water permeability render it a good candidate for developing efficient carriers for anticancer agents. Cellulose based nanomaterials like cellulose nanofibers, bacterial cellulose, cellulose nanocrystals and microcrystalline cellulose as delivery vehicles for targeted drug delivery to cancer cells are reviewed. This review elaborates on the synthesis, functionalization, and application strategies of these nanocarriers, and shows how they facilitate to improve drug stability, bioavailability and targeted delivery to tumor sites. Their possibilities as a tool to overcome the limitations of conventional cancer therapeutics are also discussed. We also explore future directions for improving the efficacy of cellulose based carriers in cancer therapy.

Insights into bacterial cellulose for adsorption and sustained-release mechanism of flavors

The stabilities and sustained-release properties of citral are significant for foods. Herein, bacterial cellulose (BC) was innovatively reported for adsorption and sustained-release of citral via gas-phase adsorption technique, and the adsorption mechanism was disclosed. BC was prepared from tobacco stem waste extract (TSWE), and better adsorption capacity (124.98 mg/g) was obtained through response surface optimization. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Flourier transform Infrared Spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) were utilized to verify the successful adsorption. Thermo-gravimetry (TG) analysis showed that the release of citral was delayed. Temperature responsiveness indicated the release of citral was controlled by internal diffusion. Density functional theory (DFT) calculations indicated the interactions between BC and citral was mainly composed of van der Waals forces and hydrogen bonds. BC-Citral also exhibited excellent antibacterial capability. This work provided a new approach for constructing controlled-release materials of citral, which offered good application prospects in food industry.

3D printing of bacterial cellulose for potential wound healing applications: Current trends and prospects

Several advances in skin tissue engineering have been made to restore skin damage, facilitating wound healing. Bacterial cellulose (BC), a naturally occurring polymer, has gained attention as a potential material in wound healing due to its unique physical and biological properties. In recent years, with the advent of 3D bio-printing technology, new avenues have opened for fabricating customized wound dressings and scaffolds for tissue engineering purposes. The existing literature in this field mainly focuses on the ways of modifications of bacterial cellulose to make it printable. Still, the applicability of 3D printed scaffolds for wound healing needs to be explored more. This review article focuses on the current research on using 3D-printed BC for skin regeneration, including its production methods and physical and biological properties, making it a better choice than traditional dressings. Furthermore, it also highlights the limitations and future directions for using BC in wound healing and tissue engineering applications. This review provides a comprehensive and up-to-date exploration of the applications of 3D-printed BC in wound healing, drawing insights from pre-existing studies and emphasizing patient compliance, clinical outcomes, and economic viability.

Nanocellulose-based conductive composites: A review of systems for electromagnetic interference shielding applications

Electronic systems and telecommunications have grown in popularity, leading to increasing electromagnetic (EM) radiation pollution. Environmental protection from EM radiation demands the use of environmentally friendly products. The design of EM interference (EMI) shielding materials using resources like nanocellulose (NC) is gaining traction. Cellulose, owing to its biocompatibility, biodegradability, and excellent mechanical and thermal properties, has attracted significant interest for developing EMI shielding materials. Recent advancements in cellulose-based EMI shielding materials, particularly modified cellulosic composites, are highlighted in this study. By incorporating metallic coatings compounded with conductive fillers and modified with inherently conductive elements, conductivity and effectiveness of EMI shielding can be significantly improved. This review discusses the introduction of EMI shields, cellulose, and NC, assessing environmentally friendly EMI shield options and diverse NC-based composite EMI shields considering their low reflectivity. The study offers new insights into designing advanced NC-based conductive composites for EMI shielding applications.

Balancing mechanical property and swelling behavior of bacterial cellulose film by in-situ adding chitosan oligosaccharide and covalent crosslinking with γ-PGA

Bacterial cellulose (BC) is an ideal candidate material for drug delivery, but the disbalance between the swelling behavior and mechanical properties limits its application. In this work, covalent crosslinking of γ-polyglutamic acid (γ-PGA) with the chitosan oligosaccharide (COS) embedded in BC was designed to remove the limitation. As a result, the dosage, time, and batch of COS addition significantly affected the mechanical properties and the yield of bacterial cellulose complex film (BCCF). The addition of 2.25 % COS at the incubation time of 0.5, 1.5, and 2 d increased the Young's modulus and the yield by 5.65 and 1.42 times, respectively, but decreased the swelling behavior to 1774 %, 46 % of that of native BC. Covalent γ-PGA transformed the dendritic structure of BCCF into a spider network, decreasing the porosity and increasing the swelling behavior by 3.46 times. The strategy balanced the swelling behavior and mechanical properties through tunning hydrogen bond, electrostatic interaction, and amido bond. The modified BCCF exhibited a desired behavior of benzalkonium chlorides transport, competent for drug delivery. Thereby, the strategy will be a competent candidate to modify BC for such potential applications as wound dressing, artificial skin, scar-inhibiting patch, and so on.

Functionalization of bacterial cellulose: Exploring diverse applications and biomedical innovations: A review

The demand for the functionalization of additive materials based on bacterial cellulose (BC) is currently high due to their potential applications across various sectors. The preparation of BC-based additive materials typically involves two approaches: in situ and ex situ. In situ modifications entail the incorporation of additive materials, such as soluble and dispersed substances, which are non-toxic and not essential for bacterial cell growth during the production process. However, these materials can impact the yield and self-assembly of BC. In contrast, ex situ modification occurs subsequent to the formation of BC, where the additive materials are not only adsorbed on the surface but also impregnated into the BC pellicle, while the BC slurry was homogenized with other additive materials and gelling agents to create composite films using the casting method. This review will primarily focus on the in situ and ex situ functionalization of BC then sheds light on the pivotal role of functionalized BC in advancing biomedical technologies, wound healing, tissue engineering, drug delivery, bone regeneration, and biosensors.

Preparation and characterization of bacterial cellulose synthesized by kombucha from vinegar residue

Bacterial cellulose (BC) has been widely applied in various fields due to its excellent physicochemical properties, but its high production cost remains a challenge. Herein, the present study aimed to utilize the hydrolysate of vinegar residue (VR) as the only medium to realize the cost-effective production of BC. The BC production was optimized by the single-factor test. The treatment of 6 % VR concentration with 3 % acid concentration at 100 °C for 1.5 h and 96 U/mL of cellulase for 4 h at 50 °C obtained a maximum reducing sugar concentration of about 32 g/L. Additionally, the VR hydrolysate treated with 3 % active carbon (AC) at 40 °C for 0.5 h achieved a total phenol removal ratio of 86 %. The yield of BC reached 2.1 g/L under the optimum conditions, which was twice compared to the standard medium. The produced BC was characterized by SEM, FT-IR, XRD, and TGA analyses, and the results indicated that the BC prepared by AC-treated VR hydrolysate had higher fiber density, higher crystallinity, and good thermal stability. Furthermore, the regenerated BC (RBC) fibers with a tensile stress of 400 MPa were prepared successfully using AmimCl solution as a solvent by dry-wet-spinning method. Overall, the VR waste could be used as an alternative carbon source for the sustainable production of BC, which could be further applied to RBC fibers preparation.

Effect of in-situ biochemical modification on the synthesis, structure, and function of xanthan gum based bacterial cellulose generated from Tieguanyin oolong tea residue hydrolysate

The effect of in-situ biochemical modification on the synthesis, structure, and function of xanthan gum based bacterial cellulose generated from Tieguanyin oolong tea residue hydrolysate was evaluated for the first time. This modification could overcome the inhibitory effect of the hydrolysate and the bacterial cellulose yield with 0.6% xanthan gum addition increased by 260.8% compared with that without xanthan gum addition. Bacterial cellulose and xanthan gum were combined by the in-situ modification and the alteration of fermentation medium rheological properties by xanthan gum addition might be beneficial for their combination. The average diameter of the bacterial cellulose microfibrils was increased by the modification, and it had a great influence on the crystalline structure of the bacterial cellulose. Additionally, both the water absorption and texture properties of the bacterial cellulose was strengthened by the modification. Overall, this modification showed great potential for efficient and effective xanthan gum based bacterial cellulose production.

Bacterial cellulose/gum Arabic composite production by in-situ modification from lavender residue hydrolysate

In this study, bacterial cellulose/gum Arabic composite (BC/GA) was synthesized by in-situ modification from lavender residue hydrolysate for the first time. The in-situ modification with GA adding showed great beneficial effect for BC/GA synthesis. Both the product (BC or BC/GA) yield and the product (BC or BC/GA) production per sugars consumption increased greatly by the in-situ modification when compared with the fermentation without GA adding (2.90 g/L vs. 0.91 g/L, and 0.461 g/g vs. 0.138 g/g). It is hypothesized that the combination of BC and GA is the main mechanism for the beneficial effect of the in-situ modification, and the scanning electron microscope (SEM) images confirmed this hypothesis. GA adding showed little effect on the rheological properties of lavender residue hydrolysate, and this environment was suitable for the combination of BC and GA. The in-situ modification had an obvious influence on the crystallinity index and the thermal stability of BC/GA, but affected little on its functional groups and cellulose structural framework. Besides BC/GA synthesis and structure, the in-situ modification could also alter the texture properties of BC/GA. Overall, this study can offer some useful information for the biochemical conversion from green and cost-effective lavender residue hydrolysate to attractive biomaterial BC/GA.

Modification of microstructure and selected physicochemical properties of bacterial cellulose produced by bacterial isolate using hydrocolloid-fortified Hestrin-Schramm medium

Bacterial cellulose (BC) is a biopolymer with applications in numerous industries such as food and pharmaceutical sectors. In this study, various hydrocolloids including modified starches (oxidized starch-1404 and hydroxypropyl starch-1440), locust bean gum, xanthan gum (XG), guar gum, and carboxymethyl cellulose were added to the Hestrin-Schramm medium to improve the production performance and microstructure of BC by Gluconacetobacter entanii isolated from coconut water. After 14-day fermentation, medium supplemented with 0.1% carboxymethyl cellulose and 0.1% XG resulted in the highest BC yield with dry BC content of 9.82 and 6.06 g/L, respectively. In addition, scanning electron microscopy showed that all modified films have the characteristic three-dimensional network of cellulose nanofibers with dense structure and low porosity as well as larger fiber size compared to control. X-ray diffraction indicated that BC fortified with carboxymethyl cellulose exhibited lower crystallinity while Fourier infrared spectroscopy showed characteristic peaks of both control and modified BC films.

Recycling utilization of Chinese medicine herbal residues resources: systematic evaluation on industrializable treatment modes

Traditional Chinese medicine (TCM) is an indispensable part of the world health and medical system and plays an important role in treatment, prevention, and health care. These TCM produce a large amount of Chinese medicine herbal residues (CHMRs) during the application process, most of which are the residues after the decoction or extraction of botanical medicines. These CMHRs contain a large number of unused components, which can be used in medical, breeding, planting, materials, and other industries. Considering the practical application requirements, this paper mainly introduces the low-cost treatment methods of CHMRs, including the extraction of active ingredients, cultivation of edible fungi, and manufacture of feed. These methods not only have low upfront investment, but also have some income in the future. Furthermore, other methods are briefly introduced. In conclusion, this paper can provide a reference for people who need to deal with CMHRs and contribute to the sustainable development of TCM.

Characterization of isolated starch from Isatis indigotica Fort. root and anhydro-sugars preparation using its decoction residues

Isatis indigotica Fort. root (Ban-lan-gen, IIR), a traditional Chinese medicine (TCM), has an ancient and well-documented history for its medicinal properties. Aside from epigoitrin, indole alkaloids, and their corresponding derivatives as medicinal ingredients, it also contains lots of biomass such as starch. Herein, a new starch was isolated from IIR and the physicochemical properties such as amylose content, moisture content, ash content, morphology, thermal properties, and crystallography were characterized systematically. The amylose content of IIR starch was 19.84 ± 0.85%, and the size and shape of starch granules is ellipsoidal shape with sizes from 2 to 10 μm. IIR starch exhibited a C-type pattern and had 25.92% crystallinity (higher than that of corn starch). The gelatinization temperature of IIR starch was 58.68-75.41 °C, and its gelatinization enthalpy was ΔH gel = 4.33 J/g. After decocting, the IIR's residues can be used to prepare anhydro-sugars in a polar aprotic solvent. The total carbon yield of levoglucosan (LG), levoglucosenone (LGO), 5-hydroxymethylfurfural (HMF), and furfural (FF) could reach 69.81% from IIR's decoction residues in 1,4-dioxane with 15 mM H2SO4 as the catalyst. Further, the residues after dehydration were prepared into biochar by thermochemical conversion and the BET surface area of biochar was 1749.46 m2/g which has good application prospect in soil improvement and alleviates obstacles of IIR continuous cropping.

Accurate delivery of pristimerin and paclitaxel by folic acid-linked nano-micelles for enhancing chemosensitivity in cancer therapy

Chemoresistance remains a huge challenge for effective treatment of non-small cell lung cancer (NSCLC). Previous studies have shown Chinese herbal extracts possess great potential in ameliorating tumor chemoresistance, however, the efficacy is clinically limited mainly because of the poor tumor-targeting and in vivo stability. The construction of nano-delivery systems for herbal extracts has been shown to improve drug targeting, enhance therapeutic efficacy and reduce toxic and side effects. In this study, a folic acid (FA)-modified nano-herb micelle was developed for codelivery of pristimerin (PRI) and paclitaxel (PTX) to enhance chemosensitivity of NSCLC, in which PRI could synergistically enhance PTX-induced growth inhibition of A549 cancer cell. PTX was firstly grafted with the FA-linked polyethylene glycol (PEG) and then encapsulated with PRI to construct the PRI@FA-PEG-PTX (P@FPP) nano-micelles (NMs), which exhibited improved tumor-targeting and in vivo stability. This active-targeting P@FPP NMs displayed excellent tumor-targeting characteristics without obvious toxicity. Moreover, inhibition of tumor growth and metastasis induced by P@FPP NMs were significantly enhanced compared with the combined effects of the two drugs (PRI in combination of PTX), which associated with epithelial mesenchymal transition inhibition to some extent. Overall, this active-targeting NMs provides a versatile nano-herb strategy for improving tumor-targeting of Chinese herbal extracts, which may help in the promotion of enhancing chemosensitivity of NSCLC in clinical applications.

Developments in bioprocess for bacterial cellulose production

Bacterial cellulose (BC) represents a novel bio-origin nonomaterial with its unique properties having diverse applications. Increased market demand and low yield are the major reason for its higher cost. Bacteria belonging to Komagataeibacter sp are the most exploited ones for BC production. Development of a cost-effective bioprocess for higher BC production is desirable. Though static fermentation modes have been majorly employed for BC production using tray fermenters, agitated mode has also been employed successfully with air-lift fermenters as well as stirred tank reactors. Bioprocess advances in recent years has led BC production to an upper level; however, challenges of aeration requirement and labor cost towards the higher end is associated with static cultivation at large scale. We have discussed the bioprocess development for BC production in recent years along with the challenges associated and the path forward.

Green and efficient in-situ biosynthesis of antioxidant and antibacterial bacterial cellulose using wine pomace

Biologically active bacterial cellulose (BC) was efficiently synthesized in situ using wine pomace and its hydrolysate. The structural and biomechanical properties together with the biological functions of the BC were investigated. Functional BC from wine pomace and its enzymatic hydrolysate were of high purity and had higher crystallinity indexes (90.61% and 89.88%, respectively) than that from HS medium (82.26%). FTIR results proved the in-situ bindings of polyphenols to the functionalized BC. Compared to BC from HS medium, wine pomace-based BC had more densely packed ultrafine fibrils, higher diameter range distributions of fiber ribbon, but lower thermal decomposition temperatures, as revealed by the SEM micrographs and DSC data. Meanwhile, wine pomace-based BC exhibited higher loads in tensile strength and higher hardness (4.95 ± 0.31 N and 5.13 ± 0.63 N, respectively) than BC in HS medium (3.43 ± 0.14 N). Furthermore, BC synthesized from wine pomace hydrolysate exhibited a slower release rate of phenolic compounds, and possessed more antioxidant activities and better bacteriostatic effects than BC from wine pomace. These results demonstrate that BC synthesized in situ from wine pomace (especially from enzymatic hydrolysate) is a promising biomolecule with a potential application in wound dressing, tissue engineering, and other biomedical fields.