Inulin and poly(acrylic acid) grafted inulin for dissolution enhancement and preliminary controlled release of poorly water-soluble Irbesartan drug

Acylated Inulin as a Potential Shale Hydration Inhibitor in Water Based Drilling Fluids for Wellbore Stabilization

Shale hydration dispersion and swelling are primary causes of wellbore instability in oil and gas reservoir exploration. In this study, inulin, a fructo-oligosaccharide extracted from Jerusalem artichoke roots, was modified by acylation with three acyl chlorides, and the products (C10-, C12-, and C14-inulin) were investigated for their use as novel shale hydration inhibitors. The inhibition properties were evaluated through the shale cuttings hot-rolling dispersion test, the sodium-based bentonite hydration test, and capillary suction. The three acylated inulins exhibited superb hydration-inhibiting performance at low concentrations, compared to the commonly used inhibitors of KCl and poly (ester amine). An inhibition mechanism was proposed based on surface tension measurements, contact angle measurements, Fourier-transform infrared analysis, and scanning electron microscopy. The acylated inulin reduced the water surface tension significantly, thus, retarding the invasion of water into the shale formation. Then, the acylated inulin was adsorbed onto the shale surface by hydrogen bonding to form a compact, sealed, hydrophobic membrane. Furthermore, the acylated inulins are non-toxic and biodegradable, which meet the increasingly stringent environmental regulations in this field. This method might provide a new avenue for developing high-performance and ecofriendly shale hydration inhibitors.

Investigating the cryoprotective efficacy of fructans in mammalian cell systems via a structure-functional perspective

Fructans have long been known with their role in protecting organisms against various stress factors due to their ability to induce controlled dehydration and support membrane stability. Considering the vital importance of such features in cryo-technologies, this study aimed to explore the cryoprotective efficacy of fructans in mammalian cell systems where structurally different fructan polymers were examined on in vitro cell models derived from organs such as the liver, frequently used in transplantation, osteoblast, and cord cells, commonly employed in cell banking, as well as human seminal fluids that are of vital importance in assisted reproductive technology. To gain insights into the fructan/membrane interplay, structural differences were linked to rheological properties as well as to lipid membrane interactions where both fluorescein leakage from unilamellar liposomes and membrane integrity of osteoblast cells were monitored. High survival rates obtained with human endothelial, osteoblast and liver cells for up to two months clearly showed that fructans could be considered as effective non-permeating cryoprotectants, especially for extended periods of cryopreservation. In trials with human seminal fluid, short chained levan in combination with human serum albumin and glycerol proved very effective in preserving semen samples across multiple patients without any morphological abnormalities.

Inulin extraction from Stevia rebaudiana roots in an autoclave

Inulin is a polymer of d-fructose, characterized by the presence of a terminal glucose, and are a major component of Stevia rebaudiana roots. This type of polymer has nutritional properties and technological applications, such as fat substitutes in low-calorie foods and as the coating of pharmaceuticals. The aim of this study was to evaluate an alternative method for inulin extraction, in terms of extraction time and yield, since the traditional method of extraction under reflux is both time and energy consuming. Using the response surface methodology (RSM) with Box-Behnken design it was observed that the alternative extraction method using autoclave presented similar yields to the reflux-based method, but with a shorter extraction time, 121 °C by 17.41 min ¹H Nuclear Magnetic Resonance and Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-ToF-MS) analysis showed that inulin crude extract from S. rebaudiana roots obtained by autoclave extraction had a higher degree of polymerization when compared to those obtained by the traditional method. Thus, it is concluded that the proposed method using an autoclave is a faster alternative for the extraction of inulin.

Controlled Cascade-Release and High Selective Sterilization by Core-Shell Nanogels for Microenvironment Regulation of Aerobic Vaginitis

Aerobic vaginitis (AV) is a gynecological disease associated with vaginal flora imbalance. The nonselective bactericidal nature of antibiotics and low customization rate of probiotic supplementation in existing treatments lead to AV recurrence. Here, a drug delivery strategy is proposed that works with the changing dynamics of the bacterial flora. In particular, a core-shell nanogel (CSNG) is designed to encapsulate prebiotic inulin and antimicrobial peptide Cath 30. The proposed strategy allows for the sequential release of both drugs using gelatinase produced by AV pathogenic bacteria, initially selectively killing pathogenic bacteria and subsequently promoting the proliferation of beneficial bacteria in the vagina. In a simulated infection environment in vitro, the outer layer of CSNGs, Cath 30 is rapidly degraded and potently killed the pathogenic bacterium Staphylococcus aureus at 2-6 h. CSNGs enhances proliferation of the beneficial bacterium Lactobacillus crispatus by more than 50% at 24 h. In a rat AV model, the drug delivery strategy precisely regulated the bacterial microenvironment while controlling the inflammatory response of the vaginal microenvironment. This new treatment approach, configured on demand and precisely controlled, offers a new strategy for the treatment of vaginal diseases.

Fabrication of graphene oxide/inulin impregnated with ZnO nanoparticles for efficient removal of enrofloxacin from water: Taguchi-optimized experimental analysis

A novel nano-adsorbent zinc oxide impregnated graphene oxide/inulin (ZGI) was prepared for the investigation of the removal efficiency of enrofloxacin. Characterization of the nano-adsorbent was accomplished through Fourier transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with EDS, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The average crystallite size of nanomaterial (ZGI) calculated from XRD data was 14.82 nm. The adsorption of enrofloxacin onto ZGI was performed in batch mode. The variables of adsorption process such as adsorbent dose, pH, contact time and initial concentration of enrofloxacin were optimized by Taguchi method to achieve the maximum removal efficiency. The optimum values of variables were: adsorbent dose = 25 mg, pH = 7, contact time = 60 min and initial concentration = 50 mg/L. The maximum adsorption capacity and removal efficiency of the material for enrofloxacin were 317.83 mg/g and 98.60%, respectively at 303 K. Redlich-Peterson isotherm model was the best fitted among the various isotherm models based on highest R² values (0.9978-0.9981) and lowest χ² (3.43 ×10^-4-2.00×10^-3). Kinetic data followed pseudo-second order model (R² ≥ 0.9974) more accurately as compared to pseudo-first order model (R²≤0.9772). The adsorption mechanism was illustrated on the basis of XPS and Raman studies. Reusability investigation showed that the nano-adsorbent ZGI could be used up to 5 adsorption-desorption cycles with greater than 90% removal efficiency.

Bioactive polysaccharides and oligosaccharides from garlic (Allium sativum L.): Production, physicochemical and biological properties, and structure-function relationships

Garlic is a common food, and many of its biological functions are attributed to its components including functional carbohydrates. Garlic polysaccharides and oligosaccharides as main components are understudied but have future value due to the growing demand for bioactive polysaccharides/oligosaccharides from natural sources. Garlic polysaccharides have molecular weights of 1 × 10³ to 2 × 10⁶  Da, containing small amounts of pectins and fructooligosaccharides and large amounts of inulin-type fructans ((2→1)-linked β-d-Fruf backbones alone or with attached (2→6)-linked β-d-Fruf branched chains). This article provides a detailed review of research progress and identifies knowledge gaps in extraction, production, composition, molecular characteristics, structural features, physicochemical properties, bioactivities, and structure-function relationships of garlic polysaccharides/oligosaccharides. Whether the extraction processes, synthesis approaches, and modification methods established for other non-garlic polysaccharides are also effective for garlic polysaccharides/oligosaccharides (to preserve their desired molecular structures and bioactivities) requires verification. The metabolic processes of ingested garlic polysaccharides/oligosaccharides (as food ingredients/dietary supplements), their modes of action in healthy humans or populations with chronic conditions, and molecular/chain organization-bioactivity relationships remain unclear. Future research directions related to garlic polysaccharides/oligosaccharides are discussed.

Facile synthesis, characterization, antioxidant activity, and antibacterial activity of carboxymethyl inulin salt derivatives

A series of novel carboxymethyl inulin derivatives bearing thiosemicarbazide salts, aminoguanidine salts, and aniline salts were prepared via a facile method and employed to evaluate in vitro antioxidant activity and antibacterial activity. Their structures were characterized by Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The characterization results confirmed the successful synthesis of carboxymethyl inulin salt derivatives. The in vitro antioxidant activity evaluation results presented a significant improved superoxide radical scavenging ability, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, and reducing ability of carboxymethyl inulin salt derivatives as compared to inulin and carboxymethyl inulin. In particular, the series of carboxymethyl inulin derivatives containing thiosemicarbazide salts and aminoguanidine salts showed remarkable free radical scavenging ability and reducing ability. Moreover, the carboxymethyl inulin derivatives containing thiosemicarbazide salts and aniline salts displayed potential antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria. The cytotoxicity assay was also carried out on L929 cells by CCK-8 method, and all samples showed weak cytotoxicity. Furthermore, hemolysis results showed no hemolytic activity of most prepared inulin derivatives. In summary, the inulin derivatives containing thiosemicarbazide salts exhibited outstanding antioxidant activity, antibacterial activity, and biocompatibility, and the all-inclusive properties highlighted their potential use in food and medical applications.

Inulin and Its Application in Drug Delivery

Inulin’s unique and flexible structure, stabilization/protective effects, and organ targeting ability make it an excellent drug delivery carrier compared to other biodegradable polysaccharides. The three hydroxyl groups attached to each fructose unit serve as an anchor for chemical modification. This, in turn, helps in increasing bioavailability, improving cellular uptake, and achieving targeted, sustained, and controlled release of drugs and biomolecules. This review focuses on the various types of inulin drug delivery systems such as hydrogel, conjugates, nanoparticles, microparticles, micelles, liposomes, complexes, prodrugs, and solid dispersion. The preparation and applications of the different inulin drug delivery systems are further discussed. This work highlights the fact that modification of inulin allows the use of this polymer as multifunctional scaffolds for different drug delivery systems.

The physiological functions and pharmaceutical applications of inulin: A review

Inulin (IN), a fructan-type plant polysaccharide, is widely found in nature. The major plant sources of IN include chicory, Jerusalem artichoke, dahlia etc. Studies have found that IN possessed a wide array of biological activities, e.g. as a prebiotic to improve the intestinal microbe environment, regulating blood sugar, regulating blood lipids, antioxidant, anticancer, immune regulation and so on. Currently, IN is widely used in the food and pharmaceutical industries. IN can be used as thickener, fat replacer, sweetener and water retaining agent in the food industry. IN also can be applied in the pharmaceutics as stabilizer, drug carrier, and auxiliary therapeutic agent for certain diseases such as constipation and diabetes. This paper reviews the physiological functions of IN and its applications in the field of pharmaceutics, analyzes its present research status and future research direction. This review will serve as a one-in-all resource for the researchers who are interested to work on IN.

Influence of Oxidation Degree on the Physicochemical Properties of Oxidized Inulin

This paper reports the oxidation of inulin using varying ratios of sodium periodate and the characterization of the inulin polyaldehyde. The physicochemical properties of the inulin polyaldehyde (oxidized inulin) were characterized using different techniques including 1D NMR spectroscopy, ¹³C Nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC), ultraviolet-visible spectroscopy (UV), and scanning electron microscopy (SEM). The aldehyde peak was not very visible in the FTIR, because the aldehyde functional group exists in a masked form (hemiacetal). The thermal stability of the oxidized inulin decreased with the increasing oxidation degree. The smooth spherical shape of raw inulin was destructed due to the oxidation, as confirmed by the SEM result. The ¹HNMR results show some new peaks from 4.8 to 5.0 as well as around 5.63 ppm. However, no aldehyde peak was found around 9.7 ppm. This can be attributed to the hemiacetal. The reaction of oxidized inulin with tert-butyl carbazate produced a carbazone conjugate. There was clear evidence of decreased peak intensity for the proton belonging to the hemiacetal group. This clearly shows that not all of the hemiacetal group can be reverted by carbazate. In conclusion, this work provides vital information as regards changes in the physicochemical properties of the oxidized inulin, which has direct implications when considering the further utilization of this biomaterial.

Preparation and Characterization of Oxidized Inulin Hydrogel for Controlled Drug Delivery

Inulin-based hydrogels are useful carriers for the delivery of drugs in the colon-targeted system and in other biomedical applications. In this project, inulin hydrogels were fabricated by crosslinking oxidized inulin with adipic acid dihydrazide (AAD) without the use of a catalyst or initiator. The physicochemical properties of the obtained hydrogels were further characterized using different techniques, such as swelling experiments, in vitro drug release, degradation, and biocompatibility tests. The crosslinking was confirmed with Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC). In vitro releases of 5-fluorouracil (5FU) from the various inulin hydrogels was enhanced in acidic conditions (pH 5) compared with physiological pH (pH 7.4). In addition, blank gels did not show any appreciable cytotoxicity, whereas 5FU-loaded hydrogels demonstrated efficacy against HCT116 colon cancer cells, which further confirms the potential use of these delivery platforms for direct targeting of 5-FU to the colon.

Enhanced storage stability of solid lipid nanoparticles by surface modification of comb-shaped amphiphilic inulin derivatives

Solid lipid nanoparticles (SLNs) have been widely used as a vehicle for drug delivery. However, highly ordered lipid lattices and poor storage stability limit their practical application. Highly ordered crystal lattices may result from the low drug payload. In addition, the lipid matrix of SLNs may undergo a polymorphic transition from high energy and disordered modifications to low energy and ordered modifications during storage. This leads to drug expulsion and precipitation. Meanwhile, SLNs are susceptible to particle aggregation and size growth during storage. To improve the performance of SLNs, two comb-shaped amphiphilic macromolecular materials (CAMs), dodecyl inulin (Inu12) and octadecyl inulin (Inu18), were synthesized and utilized as emulsifiers to modify and stabilize SLNs (Inu12/Inu18-SLNs). The results indicated that Inu12 and Inu18 could more effectively reduce the lipid crystallinity and crystal lattice order of fresh SLNs versus Poloxamer 188 and Tween-80. Moreover, after six months of storage at 4 °C or 25 °C, both blank and Cyclosporine A (CsA)-loaded Inu12/Inu18-SLNs had a slower crystal transition than Tween/P188-SLNs. The particle size increases of Inu12/Inu18-SLNs were much smaller than those of Tween/P188-SLNs. The drug encapsulation efficiencies of CsA-loaded Inu12/Inu18-SLNs during storage decreased more slowly than Tween-SLNs. Therefore, Inu12 and Inu18 could more effectively inhibit lipid crystal transition and prevent particle aggregation during storage. This, in turn, leads to better storage physical stability of SLNs. Thus, the Inu12 and Inu18 CAMs were superior to Tween-80 and Poloxamer 188 (common straight-chain surfactants).

Design and Characterization of Inulin Conjugate for Improved Intracellular and Targeted Delivery of Pyrazinoic Acid to Monocytes

The propensity of monocytes to migrate into sites of mycobacterium tuberculosis (TB) infection and then become infected themselves makes them potential targets for delivery of drugs intracellularly to the tubercle bacilli reservoir. Conventional TB drugs are less effective because of poor intracellular delivery to this bacterial sanctuary. This study highlights the potential of using semicrystalline delta inulin particles that are readily internalised by monocytes for a monocyte-based drug delivery system. Pyrazinoic acid was successfully attached covalently to the delta inulin particles via a labile linker. The formation of new conjugate and amide bond was confirmed using zeta potential, Proton Nuclear Magnetic Resonance (1HNMR) and Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) confirmed that no significant change in size after conjugation which is an important parameter for monocyte targeting. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to establish the change in thermal properties. The analysis of in-vitro release demonstrated pH-triggered drug cleavage off the delta inulin particles that followed a first-order kinetic process. The efficient targeting ability of the conjugate for RAW 264.7 monocytic cells was supported by cellular uptake studies. Overall, our finding confirmed that semicrystalline delta inulin particles (MPI) can be modified covalently with drugs and such conjugates allow intracellular drug delivery and uptake into monocytes, making this system potentially useful for the treatment of TB.

Inulin: A novel and stretchy polysaccharide tool for biomedical and nutritional applications

Inulin (INU) is a flexible, fructan type polysaccharide carbohydrate, mainly obtained from the root of chicory. It is a water-soluble dietary fibre and has been recently approved by the Food and Drug Administration for improving the nutritional values of food products. INU is not digested or fermented in the initial portion of the human digestive system and directly reaches on the distal portion of the colon. Owing to this superior property, INU is specially applied to develop specific carrier systems for localized delivery of drugs related to colon diseases. Several studies proved that the fermented bi-products of INU help the growth and stimulating activity of colon bacteria e.g. Bifidobacterium and Lactobacilli. INU also has several inherent therapeutic effects like reduction of tumor risks, help in calcium ion absorption, anti-inflammatory, antioxidant properties etc. Apart from these, INU has been used for different pharmaceutical applications as a drug carrier, stabilizing agent, cryoprotectant, and an alternative to fats and sugars. Here, we review the applications of INU in different areas of biomedical science, look back into the nutritional effects of INU and outline various routes of administration of INU-based formulations.

Effect of drying parameters on the physical, morphological and thermal properties of spray-dried inulin

This study focuses on the thermal, morphological and physical properties of spray-dried chicory root inulin using a thermogravimetric analyzer, environmental scanning electron microscopy, X-ray diffractogram and modulated differential scanning calorimetry. Different spray-drying conditions were investigated by varying inlet temperature, outlet temperature and aspirator speed. The starting material was semicrystalline. A feed temperature of 95°C was employed, which produced a completely transparent solution for spray drying. At that particular temperature, the powder samples obtained were entirely amorphous and morphology resembled each other except for higher solid content. The low glass transition temperature (T g) (106.83°C) was evident by treating low-molecular-weight samples, whereas high-molecular-weight samples exhibited high T g (125.81°C). The semicrystalline samples due to the high concentration and milky dispersion exhibited high decomposition temperature. The feed temperature, molecular weight and concentration of the samples tend to have a significant effect on the properties of spray-dried inulin.

Synthesis, characterisation and physicochemical properties of hydrophobically modified inulin using long-chain fatty acyl chlorides

A series of inulin derivatives were synthesized in aqueous solution using acyl chlorides with varying alkyl chain length (C10-C16). They were characterised using a number of techniques including MALDI TOF-MS, ¹H NMR and FTIR and their degree of substitution determined. The solution properties of the hydrophobically modified inulins were investigated using dye solubilisation and surface tension and it was confirmed that the molecules aggregated in solution above a critical concentration (critical aggregation concentration, CAC). The value of the CAC was found to be reasonably consistent between the different techniques and was shown to decrease with increasing hydrophobe chain length. It was found that the C10, C12 and C14 derivatives formed stable oil-in-water emulsions and the emulsion droplet size decreased with increasing alkyl chain length. The C16 derivative was not able to produce stable oil-in-water emulsions; however, it was able to form stable water-in-oil emulsions. The fact that the derivatives are able to form micellar-like aggregates and stabilise emulsions makes them suitable candidates for the encapsulation and delivery of active compounds with potential application in food, cosmetic, personal care and pharmaceutical formulations.

Hydroxypropyl-β-cyclodextrin functionalized calcium carbonate microparticles as a potential carrier for enhancing oral delivery of water-insoluble drugs

The objective of the present study was to demonstrate that a novel hydroxypropyl-β-cyclodextrin functionalized calcium carbonate (HP-β-CD/CC) based amorphous solid dispersion (ASD) can be used to increase the solubility and oral bioavailability of water-insoluble drugs. Irbesartan (IRB) was selected as a model compound and loaded into the nanoporous HP-β-CD/CC matrix using an immersion method. The IRB-loaded HP-β-CD/CC formulation was characterized by various analytical techniques, such as specific surface area analysis, scanning electron microscopy (SEM), dynamic light scattering (DLS), powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC). Analyses with PXRD and DSC confirmed that IRB was fully converted into the amorphous form in the nanopores of HP-β-CD/CC. From the solubility and dissolution tests, it was observed that the aqueous solubility and dissolution rate of IRB-loaded HP-β-CD/CC were increased significantly compared with those of pure IRB and IRB-loaded mesoporous silica. Likewise, the IRB-loaded HP-β-CD/CC formulation exhibited better absorption compared with that of the commercially available IRB capsules in beagle dogs. The mean peak plasma concentration (C max) and the area under the mean plasma concentration-time curve (AUC[0→48]) of IRB-loaded HP-β-CD/CC were 1.56- and 1.52-fold higher than that of the commercial product, respectively. Furthermore, the IRB-loaded HP-β-CD/CC formulation exhibited excellent stability against re-crystallization. These results clearly demonstrate that HP-β-CD/CC based porous ASD is a promising formulation approach to improve the aqueous solubility and the in vivo absorption performance of a water-insoluble compound like IRB.

Encapsulation of thyme (Thymus serpyllum L.) aqueous extract in calcium alginate beads

BACKGROUND

Encapsulation of Thymus serpyllum L. aqueous extract within calcium alginate beads was studied in order to produce dosage formulations containing polyphenolic compounds. Electrostatic extrusion was applied for encapsulation of thyme aqueous extract in alginate gel beads. In addition to hydrogel beads, heat-dried and freeze-dried forms of beads were examined.

METHODS

Encapsulation systems were examined and compared in order to choose the optimal one with respect to entrapment efficiency, preservation of antioxidant activity and thermal behaviour under heating conditions simulating the usual food processing.

RESULTS

The beads obtained with approximately 2 mg g⁻¹ of gallic acid equivalents encapsulated in 0.015 g mL⁻¹ of alginate were spheres of a uniform size of about 730 µm. Encapsulation efficiency varied in the range 50-80% depending on the encapsulation method. Besides, the analysis reveals that the encapsulation process and the material used did not degrade the bioactive compounds, as the total antioxidant content remained unchanged. This was verified by Fourier transform infrared analysis, which proved the absence of chemical interactions between extracted compounds and alginate. Addition of a filler substance, such as sucrose and inulin, in the dried product reduced its collapse and roundness distortion during drying process.

CONCLUSION

This study demonstrates the potential of using hydrogel material for encapsulation of plant poplyphenols to improve their functionality and stability in food products.