Investigation of chemically modified inulin as encapsulation material for pharmaceutical substances by spray-drying

Nano-in-Micro-Particles Consisting of PLGA Nanoparticles Embedded in Chitosan Microparticles via Spray-Drying Enhances Their Uptake in the Olfactory Mucosa

Intranasal delivery has gained prominence since 1990, when the olfactory mucosa was recognized as the window to the brain and the central nervous system (CNS); this has enabled the direct site specific targeting of neurological diseases for the first time. Intranasal delivery is a promising route because general limitations, such as the blood-brain barrier (BBB) are circumvented. In the treatment of multiple sclerosis (MS) or Alzheimer’s disease, for example, future treatment prospects include specialized particles as delivery vehicles. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles are well known as promising delivery systems, especially in the area of nose-to-brain (N2B) delivery. Chitosan is also broadly known as a functional additive due to its ability to open tight junctions. In this study, we produced PLGA nanoparticles of different sizes and revealed for the first time their size-time-dependent uptake mechanism into the lamina propria of porcine olfactory mucosa. The intracellular uptake was observed for 80 and 175 nm within only 5 min after application to the epithelium. After 15 min, even 520 nm particles were detected, associated with nuclei. Especially the presence of only 520 nm particles in neuronal fibers is remarkable, implying transcellular and intracellular transport via the olfactory or the trigeminal nerve to the brain and the CNS. Additionally, we developed successfully specialized Nano-in-Micro particles (NiMPs) for the first time via spray drying, consisting of PLGA nanoparticles embedded into chitosan microparticles, characterized by high encapsulation efficiencies up to 51%, reproducible and uniform size distribution, as well as smooth surface. Application of NiMPs accelerated the uptake compared to purely applied PLGA nanoparticles. NiMPs were spread over the whole transverse section of the olfactory mucosa within 15 min. Faster uptake is attributed to additional paracellular transport, which was examined via tight-junction-opening. Furthermore, a separate chitosan penetration gradient of ∼150 µm caused by dissociation from PLGA nanoparticles was observed within 15 min in the lamina propria, which was demonstrated to be proportional to an immunoreactivity gradient of CD14. Due to the beneficial properties of the utilized chitosan-derivative, regarding molecular weight (150–300 kDa), degree of deacetylation (80%), and particle size (0.1–10 µm) we concluded that M2-macrophages herein initiated an anti-inflammatory reaction, which seems to already take place within 15 min following chitosan particle application. In conclusion, we demonstrated the possibility for PLGA nanoparticles, as well as for chitosan NiMPs, to take all three prominent intranasal delivery pathways to the brain and the CNS; namely transcellular, intracellular via neuronal cells, and paracellular transport.

Bioremediation of Copper-Ions by Polymer Encapsulated and Immobilized Micrococcus Luteus

Bioremediation of copper (Cu²⁺ ) with immobilized Micrococcus luteus in polymer matrices has been broadly studied for a wide range of applications including wastewater treatment. Herein, the bioremediation efficiency based on modified immobilization techniques and by the addition of Cu²⁺ is investigated. Porous composite nonwovens with living M. luteus (living polymer composites) are prepared by encapsulation of the bacterial cells in poly(vinyl alcohol) (PVA) microparticles (M. luteus/PVA microparticles) produced by spray drying method. The M. luteus/PVA microparticles are chemically cross-linked. The hydrogel microparticles with encapsulated M. luteus are embedded in a nonwoven of poly (lactic acid) (PLA) electrospun short fibers provided by wet-laid method. Two different models of composite nonwovens are reported, in which the place position of the hydrogel PVA microparticles with encapsulated M. luteus and PLA nonwoven can affect the bioremediation process.

Poly(Vinyl Alcohol)-Hydrogel Microparticles with Soft Barrier Shell for the Encapsulation of Micrococcus luteus

The encapsulation of bacteria in polymers results in hybrid materials that are essential for the long-term biological activity of bacteria and formulations in practical applications. Here, the problem of bacterial escape and the exchange of metabolism products from hydrogel microparticles within an aqueous environment are addressed. Bacteria are encapsulated in chemically cross-linked poly(vinyl alcohol) (PVA) hydrogel-microparticles followed by their encapsulation in a pH-responsive and soft antibacterial shell of poly(N,N-diethylamino ethyl methacrylate) (PDEAEMA). This polymer shell acts selectively with regards to the mass transport in and out of the microparticle core and is affected by environmental parameters, such as pH and antibacterial effect. The pH-responsive PDEAEMA shell forms an open porous structure that accelerates nutrient transfer into the PVA core containing living Micrococcus luteus (M. luteus). Results show that the antibacterial effect of PDEAEMA retards the escape of bacteria up to 35 days when the shell is open. Additionally, the permeation of a small molecule into the gel, for example, methylene blue dye through the core/open-shell structure, certifies a flexible barrier for mass transport, which is required in the long term for the biological activity of encapsulated M. luteus.

Potential applications of hydrophobically modified inulin as an active ingredient in functional foods and drugs - A review

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Inulin is a substance found in a wide variety of fruits, vegetables, and herbs.

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Inulin was modified by physical and chemical means to improve functionality.

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HMI has been used in the stability of emulsions and suspensions.

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SCFAs inulin esters have transformed the gut microbiota and improved the bioavailability of SCFAs.

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HMI based bioconjugates, hydrogel, and nanomicelles were used as a controlled release of drugs and vaccines.

Over the past few years, hydrophobically modified inulin (HMI) has gained considerable attention due to its multitudinous features. The targeted release of drugs remains a subject of research interest. Moreover, it is important to explore the properties of short-chain fatty acids (SCFAs) inulin esters because they are less studied. Additionally, HMI has been used to stabilize various dispersion formulations, which have been observed to be safe because inulin is generally recognized as safe (GRAS). However, the results regarding HMI-based dispersion products are dispersed throughout the literature. This comprehensive review is discussed the possible limitations regarding SCFAs inulin esters, real food dispersion formulations, and HMI drugs. The results revealed that SCFAs inulin esters can regulate the human gut microbiota and increase the biological half-life of SCFAs in the human body. This comprehensive review discusses the versatility of HMI as a promising excipient for the production of hydrophobic drugs.

Optimization of inulin production process parameters using response surface methodology

Background

Chicory is one of the major source of inulin. In our study, Box–Behnken model/response surface analysis (RSM) was used for the optimization of spray drying process variables to get the maximum inulin yield from chicory (Cichorium intybus L.). For this investigation, the investigational plan utilized three process variables drying temperature (115–125 °C), creep speed (20–24 rpm), and pressure (0.02–0.04 MPa).

Result

The optimal variables established by applying the Box–Behnken model were as follows: drying temperature 119.20 °C, creep speed 21.64 rpm, and pressure 0.03 MPa. The obtained powdered inulin by spray drying was investigated for the yield value, identification, size, and surface morphology of the particle. The inulin obtained from the spray drying process consists of a fine molecule-sized white powder. Instead, the drying methods shows a significant effect on the morphology and internal configuration of the powdered inulin, as the inulin obtained from spray drying was of a widespread and uniform size and shape, with a rough surface on increase in temperature and smoother surface while increasing the creep speed. The findings indicate that the spray drying with optimum parameters resulted in maximum product yield.

Conclusion

The outcomes of the study concluded that the product yield through spray drying technique under optimized condition is optimal as compared to other drying technique. Hence, this technique may be applied at commercial scale for the production of inulin.

Stability of camu-camu encapsulated with different prebiotic biopolymers

BACKGROUND

A viable possibility for the best use of bioactive compounds present in camu-camu, fruit native to the Amazonian rainforest, is the preparation of microcapsules using different biopolymers by the spray-drying technique, which would increase the possibilities for innovation in the food industry, as well as facilitate the application in different food matrices. In this context, the chemical, physicochemical, and morphological properties and stability of camu-camu extract (peel and pulp) spray-dried using maltodextrin, inulin, and oligofructose as encapsulating agents were investigated, as well as lyophilized camu-camu extract (CEL). Different relative humidities (22%, 51%, and 75%) and temperatures (25 °C and 45 °C) were evaluated.

RESULTS

The moisture, water activity, and solubility values varied from 18.4 to 107.9 g water per kilogram dry powder, 0.06 to 0.27, and 950.80 to 920.28 g microparticles per kilogram of water respectively. Retention of the bioactive compounds varied in the ranges 5.5-7.1 g per kilogram ascorbic acid fresh weight and 7.2-9.0 g per kilogram anthocyanins fresh weight. The increase in temperature and relative humidity during storage provided a significant decrease in the stability of the bioactive compounds for all treatments. However, the CEL presented higher water adsorption kinetics and degradation under all storage conditions, indicating the importance of the use of encapsulating agents.

CONCLUSION

In general, the prebiotic biopolymers used as encapsulating agents in the microencapsulation of extracts of camu-camu by spray-drying presented satisfactory results, suggesting that this technique is an effective strategy to increase the stability of bioactive compounds contained in fruits and vegetables. © 2020 Society of Chemical Industry.

Routine, ensemble characterisation of electrophoretic mobility in high and saturated ionic dispersions

With the industrialisation of nanoparticle manufacture, the pervasive incursion of nanoparticles into the environment, the need to characterise nano-scale pharmaceuticals and living systems in replicated in vivo conditions, the continuing development of new theories to describe the electro-kinetic behaviour of nano-particles in representative ionic strengths and numerous other applications, there is an urgent requirement to provide simple and effective experimental tools to validate these models and explore new systems. Micro-electrophoresis implemented with a diffusion barrier, which isolates the dispersed phase from the electrode surface, is demonstrated as enabling such measurements for the first time, preventing the catastrophic outgassing, precipitation and sample degradation observed when the dispersed phase is in close proximity to the electrode surface. Using a measurement of a few minute's duration in a standard laboratory light scattering instrument we reproduce the theoretically predicted phenomena of asymptotic, non-zero electrophoretic mobility with increasing ionic strength, the cationic Hofmeister series dependency, charge inversion and a continuously decreasing variation in mobility with pH as molarity increases. Standard operating procedures are developed and included to encourage further work.

Delivery to the gut microbiota: A rapidly proliferating research field

The post genomic era has brought breakthroughs in our understanding of the complex and fascinating symbiosis we have with our co-evolving microbiota, and its dramatic impact on our physiology, physical and mental health, mood, interpersonal communication, and more. This fast "proliferating" knowledge, particularly related to the gut microbiota, is leading to the development of numerous technologies aimed to promote our health via prudent modulation of our gut microbiota. This review embarks on a journey through the gastrointestinal tract from a biomaterial science and engineering perspective, and focusses on the various state-of-the-art approaches proposed in research institutes and those already used in various industries and clinics, for delivery to the gut microbiota, with emphasis on the latest developments published within the last 5 years. Current and possible future trends are discussed. It seems that future development will progress toward more personalized solutions, combining high throughput diagnostic omic methods, and precision interventions.

Microencapsulation of Rhizobium leguminosarum bv. trifolii with guar gum: Preliminary approach using spray drying

Rhizobium leguminosarum bv trifolii strains TA1 and CC275e have been widely used as effective nitrogen fixing strains for white clover in New Zealand, but rhizobia survival on seeds is usually poor due to different stress conditions. The aim of this study was to select one of those commercial strains grown in a solid carrier (core) and study the influence of the core:polymer ratio in a microencapsulation process by spray drying using guar gum as coating material. First, strains TA1 and CC275e grown on peat and diatomaceous earth were exposed to temperature and desiccation stress. Both strains were stable at 40 °C and completely died after five minutes at 80 °C, while CC275e was more stable than TA1 at 60 °C. TA1 and CC275e slightly decreased viability after six hours drying with either carriers, with no differences between strains. A central composite design was used to develop the microencapsulation process. Independent variables were: inlet temperature (130 °C) and feed flow rate (5 mL/min). Microparticles presented rhizobia loading in 10⁷ CFU/g and mean particle size between 10 and 30 μm. Optimized process reached 50% yield and 10⁷ CFU/g loading. Rhizobia viability dropped two logarithmic units during the microencapsulation/drying process, possibly due to the negative effects of dehydration and high outlet temperature (≈70 °C), suggesting the need to continue optimizing the process by improving the thermal profile in the drying chamber.

Encapsulated Microparticles of (1→6)-β-d-Glucan Containing Extract of Baccharis dracunculifolia: Production and Characterization

β-Glucans are biomacromolecules well known, among other biological activities, for their immunomodulatory potential. Similarly, extracts of Baccharis dracunculifolia also possess biological properties and are used in folk medicine for the treatment of inflammation, ulcers, and hepatic diseases. Microparticles containing (1→6)-β-d-glucan (lasiodiplodan) and B. dracunculifolia extract were produced and characterized. A 23 factorial design was employed to define the conditions of production of microparticles by atomization. Lasiodiplodan associated with maltodextrin and gum arabic was studied as a matrix material. Microparticles of 0.4 μm mean size and high phenolics content (3157.9 μg GAE/g) were obtained under the optimized conditions. The microparticle size ranged from 0.23 to 1.21 µm, and the mathematical model that best represented the release kinetics of the extract was the Korsmeyer-Peppas model. Diffusional exponent (n) values of 0.64 at pH 7.7 and 1.15 at pH 2.61 were found, indicating particles with a non-Fickian or anomalous transport system, and Super Case II transport, respectively. Thermal analysis indicated that the microparticles demonstrated high thermal stability. The X-ray diffraction analyses revealed an amorphous structure, and HPLC-DAD analysis showed microparticles rich in phenolic compounds: caffeic acid, p-coumaric acid, and catechin. The microparticles obtained comprise a new biomaterial with biological potential for applications in different fields.

Inulin as a multifaceted (active) substance and its chemical functionalization: From plant extraction to applications in pharmacy, cosmetics and food

This review is aimed at critically discussing a collection of research papers on Inulin (INU) in different scientific fields. The first part of this work gives an overview on the main characteristics of native INU, including production, applications in food or cosmetics industries, its benefits on human health as well as its main nutraceutical properties. A particular focus is dedicated to the extraction techniques and to the specific effects of INU on intestinal microbiota. Other than in food industry, the number of INU applications increases dramatically in the pharmaceutical field especially due to its simple chemical functionalization. Thus, aim of this review is also to give practical examples of chemical functionalization performed on INU also by including critical comments based on the direct experience of the Authors. With this aim, a full paragraph is dedicated to practical chemical experiences useful to reduce the efforts when establishing new experimental conditions. Moreover, the pharmaceutical technology is also taken in special consideration by underlining the aspects leading at the preparation of formulations based on INU. At the end of the review, a critical paragraph is intended to feed the scientists' curiosity on this versatile polysaccharide.

Optimization of Spray-Drying Process of Jerusalem artichoke Extract for Inulin Production

Jerusalem artichoke is an important natural matrix for inulin production. In this experiment, response surface methodology (RSM) was employed to optimize the spray-drying parameters in order to determine the maximal inulin yield. For this study, three independent variables (heating temperature (Tª, 110–120 °C), creep speed (V, 18–22 rpm) and pressure (P, 0.02–0.04 MPa)) were used in the experimental design. Using the Box–Behnken design, the optimal parameters obtained were: drying temperature 114.6 °C, creep speed 20.02 rpm, and pressure: 0.03 MPa. The inulin yield, water content and particle size of inulin obtained by spray-drying and freeze-drying were compared. In this regard, the spray-dried inulin consisted of a white powder having a fine particle size, and the freeze-dried inulin had a pale-yellow fluffy floc. On the other hand, the drying methods had a great influence on the appearance and internal structure of inulin powder, since the spray-dried inulin had a complete and uniform shape and size, whereas the freeze-dried inulin had a flocculated sheet structure. The analysis showed that the spray-drying led to a higher inulin yield, lower water content and better surface structure than freeze-drying.

Degradation studies of modified inulin as potential encapsulation material for colon targeting and release of mesalamine

Due to the potential to treat colon specific diseases with reduced side effects, colon targeting has become of high interest over the last decades. Chemical modified inulin was investigated for its potential as encapsulation material regarding its enzymatic degradability and its drug release behavior. Different degrees of acetylated inulin (degree of substitution, DS, 0.3-2.1) were synthesized. The chemical modification leads to a reduction in enzymatic degradability by inulinase and esterase, enzymes which can be expressed by the colon microbiota. Acetylated inulin was only hydrolyzed to fructose units up to DS of 1.3. Microparticles made of native inulin and acetylated inulin (DS 1.8) were loaded with the colon-specific drug mesalamine by spray drying. Compared to the burst release of mesalamine by inulin particles within 6 h, acetylated inulin particles showed less burst release followed by a continuous drug release phase caused by diffusion up to 30% mesalamine after 52 h.