Self-assembled nanoparticles of acetylated cashew gum: Characterization and evaluation as potential drug carrier

A review of the fungal polysaccharides as natural biopolymers: Current applications and future perspective

As a unique natural resource, fungi are a sustainable source of lipids, polysaccharides, vitamins, proteins, and other nutrients. As a result, they have beneficial medicinal and nutritional properties. Polysaccharides are among the most significant bioactive components found in fungi. Increasing research has revealed that fungal polysaccharides (FPS) contain a variety of bioactivities, including antitumor, antioxidant, immunomodulatory, anti-inflammatory, hepatoprotective, cardioprotective, and anti-aging properties. However, the exact knowledge about FPS and their applications related to their future possibilities must be thoroughly examined to enhance a better understanding of this sustainable biopolymer source. Therefore, FPS' biological applications and their role in the food and feed industry, agriculture, and cosmetics applications were all discussed in this work. In addition, this review highlighted the mode of action of FPS on human diseases by regulating gut microbiota and discussed the mechanism of FPS as antioxidants in the living cell. The structure-activity connections of FPS were also highlighted and explored. Moreover, future perspectives were listed to pave the way for future studies of FPS applications. Hence, this study can be a scientific foundation for future FPS research and industrial applications.

Plant gums in Pickering emulsions: A review of sources, properties, applications, and future perspectives

Recently, there has been an increasing research interest in the development of Pickering emulsions stabilized with naturally derived biopolymeric particles. In this regard, plant gums, obtained as plant exudates or from plant seeds, are considered promising candidates for the development of non-toxic, biocompatible, biodegradable and eco-friendly Pickering stabilizers. The main objective of this review article is to provide a detailed overview and assess the latest advances in the formulation of Pickering emulsions stabilized with plant gum-based particles. The plant gum sources, types and properties are outlined. Besides, the current methodologies used in the production of plant gum particles formed solely of plant gums, or through interactions of plant gums with proteins or other polysaccharides are highlighted and discussed. Furthermore, the work compiles and assesses the innovative applications of plant gum-based Pickering emulsions in areas such as encapsulation and delivery of drugs and active agents, along with the utilization of these Pickering emulsions in the development of active packaging films, plant-based products and low-fat food formulations. The last part of the review presents potential future research trends that are expected to motivate and direct research to areas related to other novel food applications, as well as tissue engineering and environmental applications.

Influence of Reduction with NaBH4 and HCl in Obtaining Amino Derivatives of Cashew Gum and Cytotoxic Profile

Tree-exuded gums are natural polymers that represent an abundant raw material in the food and pharmaceutical industries. The cashew gum can be obtained by exudation of trees of the genus Anacardium, a native species of the Brazilian northeast; its polymer consists of monosaccharide units propitious to the action of chemical reactions that tend to improve their intrinsic characteristics among them, as the degree of hydro-solubility. The objective of this work was to modify the exudate gum of Anacardium occidentale (cashew gum (CG)) through an amine reaction. The modification was confirmed by Nuclear Magnetic Resonance (¹H NMR), infrared spectroscopy (FTIR), gel permeation chromatography (GPC), zeta potential, and thermogravimetric analysis (TG). In addition, the chemical modification altered the molar mass and surface charge of the CG, and the amino group binding to the CG polymers was confirmed by FTIR spectra. In addition, cytotoxicity tests were performed where cell viability was estimated by an MTT assay on RAW 264.7 macrophages. Through these tests, it was found that the amine caused an increase in the thermal stability of the amino compounds and did not present cytotoxic potential at concentrations below 50.0 mg/L.

Development of a new biomaterial based on cashew tree gum (Anarcadium occidentale L.) enriched with hydroxyapatite and evaluation of cytotoxicity in adipose-derived stem cell cultures

Cashew tree gum is a polysaccharide material highly available in the Northeast region of Brazil. It has been explored for biocompatibility with human tissues. This research aimed to describe the synthesis and characterization of cashew gum/hydroxyapatite scaffold and evaluate the possible cytotoxicity in murine adipo-derived stem cells (ADSCs) cultures. ADSCs of the subcutaneous fat tissue of Wistar rats were collected, isolated, expanded, differentiated into three strains, and characterized immunophenotypically. The scaffolds were synthesized through chemical precipitation, lyophilized and characterized through scanning electron microscopy (SEM), infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal analysis (TG and DTG), and mechanical testing. The scaffold presented a crystalline structure and pores with an average diameter of 94.45 ± 50.57 μm. By mechanical tests, the compressive force and modulus of elasticity were like the cancellous bone. The isolated adipose-derived stem cells (ADSCs) presented fibroblast morphology, adhesion capacity to plastic, differentiation in osteogenic, adipogenic and chondrogenic lineages, positive expression for the CD105 and CD90 markers and negative expression for the CD45 and CD14 markers. The MTT test showed increased cell viability, and the biomaterial showed a high level of hemocompatibility (<5 %). This study allowed the development of a new scaffold for future surgical applicability in tissue regeneration.

Insulin-loaded nanoparticles based on acetylated cashew gum/chitosan complexes for oral administration and diabetes treatment

Insulin is one of the most important drugs in the clinical treatment of diabetes. There is growing interest in oral insulin administration as it mimics the physiological pathway and potentially reduces side effects associated with subcutaneous injection. In this study, a nanoparticulate system was developed using acetylated cashew gum (ACG) and chitosan by the polyelectrolyte complexation method, for oral administration of insulin. The nanoparticles were characterized by size, zeta potential and encapsulation efficiency (EE%). And they had a particle size of 460 ± 11.0 nm, PDI of 0.2 ± 0.021, zeta potential of 30.6 ± 0.48 mV, and an EE% of 52.5 %. Cytotoxicity assays were performed for HT-29 cell lines. It was observed that ACG and nanoparticles did not have a significant effect on cell viability, verifying their biocompatibility. Hypoglycemic effects of the formulation were analyzed in vivo, noting that the nanoparticles reduced blood glucose by 51.0 % of baseline levels after 12 h, not inducing signs of toxicity or death. Biochemical and hematological profiles were not clinically modified. Histological study indicated no signs of toxicity. Results showed that the nanostructured system presented itself as a potential vehicle for oral insulin release.

A comprehensive review on pharmaceutical uses of plant-derived biopolysaccharides

Biopolysaccharides extracted from plants are mainly photosynthetic byproducts found in leaves, pods, stems, fruits, grains, seeds, corms, rhizomes, roots, bark exudates, and other plant parts. Recently, these plant-derived biopolysaccharides have received a great deal of attention as pharmaceutical excipients in a range of different dosage forms because of several key advantages, such as widespread accessibility from nature as plant-based sources are readily available, sustainable production, availability of easy and cost-effective extraction methodologies, aqueous solubility, swelling capability in the aqueous medium, non-toxicity, biodegradability, etc. The current review presents a comprehensive overview of the uses of plant-derived biopolysaccharides as effective pharmaceutical excipients in the formulations of different kinds of dosage forms, for example gels, pastes, films, emulsions, suspensions, capsules, tablets, nanoparticles, microparticles, beads, buccal formulations, transdermal formulations, ocular formulations, nasal formulations, etc.

Modification of chicha gum: Antibacterial activity, ex vivo mucoadhesion, antioxidant activity and cellular viability

The aim of the present work was to modify the exuded gum of Sterculia striata tree by an amination reaction. The viscosity and zero potential of the chicha gum varied as a function of pH. The modification was confirmed by X-ray diffraction (XRD), infrared spectroscopy (FTIR), size exclusion chromatography (SEC), zeta potential, thermogravimetric analysis (TG), and differential scanning calorimetry (DSC). Furthermore, the chemical modification changed the molar mass and surface charge of the chicha gum. In addition, the gums were used in tests for ex vivo mucoadhesion strength, antibacterial activity against the standard strain of Staphylococcus aureus (ATCC 25923), inhibitory activity of α-glucosidase, antioxidant capacity, and viability of Caco-2 cells. Through these tests, it was found that amination caused an increase in the mucoadhesive and inhibitory activity of chicha gum against the bacterium Staphylococcus aureus. In addition, the gums (pure and modified) showed antioxidant capacity and an inhibitory effect against the α-glucosidase enzyme and did not show cytotoxic potential.

Effect of Acyl Chain Length on Hydrophobized Cashew Gum Self-Assembling Nanoparticles: Colloidal Properties and Amphotericin B Delivery

Given its many potential applications, cashew gum hydrophobic derivatives have gained increasing attraction in recent years. We report here the effect of acyl chain length on hydrophobized cashew gum derivatives, using acetic, propionic, and butyric anhydrides on self-assembly nanoparticle properties and amphotericin B delivery. Nanoparticles with unimodal particle size distribution, highly negative zeta potential, and low PDI were produced. Butyrate cashew gum nanoparticles presented smaller size (<~100 nm) than acetylated and propionate cashew gum nanoparticles and no cytotoxicity in murine fibroblast cells was observed up to 100 µg/mL for loaded and unloaded nanoparticles. As a proof of concept of the potential use of the developed nanoparticle as a drug carrier formulation, amphotericin B (AmB) was encapsulated and fully characterized in their physicochemical, AmB association and release, stability, and biological aspects. They exhibited average hydrodynamic diameter lower than ~200 nm, high AmB efficiency encapsulations (up to 94.9%), and controlled release. A decrease in AmB release with the increasing of the anhydride chain length was observed, which explains the differences in antifungal activity against Candida albicans strains. An excellent storage colloidal stability was observed for unloaded and loaded AmB without use of surfactant. Considering the AmB delivery, the acyl derivative with low chain length is shown to be the best one, as it has high drug loading and AmB release, as well as low minimum inhibitory concentration against Candida albicans strains.

Chitosan-Based Nanoparticles for Cardanol-Sustained Delivery System

Cardanol, principal constituent of the technical cashew nut shell liquid, has applications as antioxidant and antibacterial, and these properties may be enhanced through encapsulation. In the present study, we isolated and purified cardanol, and nanoparticles (NPs) were produced by polyelectrolyte complexation using polysaccharide systems with chitosan, sodium alginate, and non-toxic Arabic gum, because they are biocompatible, biodegradable, and stable. We characterized the NPs for morphological, physicochemical, and antioxidant activity. The micrographs obtained revealed spherical and nanometric morphology, with 70% of the distribution ranging from 34 to 300 nm, presenting a bimodal distribution. The study of the spectra in the infrared region suggested the existence of physicochemical interactions and cross-links between the biopolymers involved in the encapsulated NPs. Furthermore, the NPs showed better antioxidant potential when compared to pure cardanol. Thus, the encapsulation of cardanol may be an effective method to maintain its properties, promote better protection of the active ingredient, minimize side effects, and can target its activities in specific locations, by inhibiting free radicals in various sectors such as pharmaceutical, nutraceutical, and biomedical.

Cashew Gum: A Review of Brazilian Patents and Pharmaceutical Applications with a Special Focus on Nanoparticles

Natural polysaccharides are structures composed of highly diversified biological macromolecules whose properties have been exploited by a diversity of industries. Until 2018, the polysaccharides market raised more than US $ 12 billion worldwide, while an annual growth forecast of 4.8% is expected by 2026. The food industry is largely responsible for the consumption of this plant-source material, produced by microbiological fermentation. Among the used polysaccharides, gums are hydrocolloids obtained from a variety of sources and in different forms, being composed of salts of calcium, potassium, magnesium and sugar monomers. Their non-toxicity, hydrophilicity, viscosity, biodegradability, biocompatibility and sustainable production are among their main advantages. Although Brazil is amongst the largest producers of cashew gum, reaching 50 tons per year, the polysaccharide is not being used to its full potential, in particular, with regard to its uses in pharmaceuticals. Cashew gum (CG), obtained from Anacardium occidentale L., caught the attention of the industry only in 1970; in 1990, its production started to grow. Within the Brazilian academy, the groups from the Federal University of Ceará and Piauí are devoting the most efforts to the study of cashew gum, with a total of 31 articles already published. The number of patents in the country for innovations containing cashew tree gum has reached 14, including the technological process for the purification of cashew tree gum, comparison of physical and chemical methods for physicochemical characterizations, and optimum purification methodology. This scenario opens a range of opportunities for the use of cashew gum, mainly in the development of new pharmaceutical products, with a special interest in nanoparticles.

Polysaccharide-Based Membrane Biocompatibility Study of Anacardium occidentale L. and Polyvinyl Alcohol after Subcutaneous Implant in Rats

Polymeric membranes are a viable and sustainable option for the biotechnology industry from an economic and environmental point of view. In this study, we evaluated tissue response and tolerance to the implantation of a polymeric membrane prepared with cashew gum polysaccharide (CGP) associated with polyvinyl alcohol (PVA). The objective was to characterize the biocompatibility of the CGP/PVA membrane in vivo. Following the evaluation criteria of the ISO 10993-6 standard, we demonstrated that the CGP/PVA membrane showed moderate tissue reaction, with a non-irritating ISO pattern, a thinner fibrous capsule, and a smaller amount of collagen compared to the positive control group. At 30 and 60 days, the membrane presented a similar amount of mast cells to that observed in the negative control group. The data demonstrate that the CGP/PVA membrane presents biocompatibility in accordance with the ISO 10993-6 standard.

Nanoemulsion of cashew gum and clove essential oil (Ocimum gratissimum Linn) potentiating antioxidant and antimicrobial activity

In this study, nanoemulsions of essential oil from Ocimumgratissimum (Linn) (EO) were produced using low and high energy techniques using cashew gum (CG) as a co-surfactant. The main constituents of the EO were determined by Gas Chromatography coupled with Mass Spectrometry (GC-MS), and their presence in the EO and in the formulations verified by Fourier Transform Infrared Spectroscopy (FTIR) and UV-visible spectrophotometry was observed the encapsulation efficiency (EE%), with colloidal stability. Nuclear magnetic resonance (NMR) was used to study cashew gum. Dynamic light scattering analysis (DLS) determined the nanoemulsion Z means, polydispersity index and the Zeta potential value, nanoparticle tracking analysis (NTA) were determined. The nanostructured EO showed better antibacterial action against the pathogenic gastroenteritis species Staphylococcus aureus, Escherichia coli and Salmonella enterica when compared to free EO. Atomic Force Microscopy (AFM) was used for morphological analysis of the nanoparticle and study of the action of the nanoemulsion through images of the cellular morphology of S. enterica. The antioxidant activity was evaluated against the ABTS radical (2,2'-azino-bis diazonium salt (3-ethylbenzothiazoline-6-sulfonic acid)). The encapsulation of EO in a nanostructured system improved its antibacterial and antioxidant activity, the low energy synthesis showed greater storage stability, remaining stable for 37 days.

Acetylated cashew gum and fucan for incorporation of lycopene rich extract from red guava (Psidium guajava L.) in nanostructured systems: Antioxidant and antitumor capacity

Industrial application of lycopene is limited due to its chemical instability and low bioavailability. This study proposes the development of fucan-coated acetylated cashew gum nanoparticles (NFGa) and acetylated cashew gum nanoparticles (NGa) for incorporation of the lycopene-rich extract from red guava (LEG). Size, polydispersity, zeta potential, nanoparticles concentration, encapsulation efficiency, transmission electron microscopy (TEM) and atomic force microscopy (AFM) were used to characterize nanoparticles. The antioxidant activity was determinated and cell viability was evaluated in the human breast cancer cells (MCF-7) and human keratinocytes (HaCaT) by MTT assay. The toxic effect was evaluated by hemolysis test and by Galleria mellonella model. NFGa showed higher stability than NGa, having a size of 162.10 ± 3.21 nm, polydispersity of 0.348 ± 0.019, zeta potential -30.70 ± 0.53 mV, concentration of 6.4 × 10⁹ nanoparticles/mL and 60% LEG encapsulation. Microscopic analysis revealed a spherical and smooth shape of NFGa. NFGa showed antioxidant capacity by ABTS method and ORAC assay. The NFGa presented significant cytotoxicity against MCF-7 from the lowest concentration tested (6.25-200 μg/mL) and did not affect the cell viability of the HaCaT. NFGa showed non-toxic effect in the in vitro and in vivo models. Therefore, NFGa may have a promising application in LEG stabilization for antioxidant and antitumor purposes.

Eco-friendly synthesis of phthalate angico gum towards nanoparticles engineering using Quality by Design (QbD) approach

We developed a new hydrophobic polymer based on angico gum (AG), and we produced new nanoparticles to expand the applications of natural polysaccharides in nanomedicine. Phthalate angico gum (PAG) was characterized by ¹H NMR, FTIR, elementary analysis, solubility, XRD, and TG. PAG was a hydrophobic and semi-crystalline material, a relevant characteristic for drug delivery system applications. As a proof of concept, nevirapine (NVP) was selected for nanoparticles development. Plackett-Burman's experimental design was used to understand the influence of several factors in nanoparticles production. PAG proved to be a versatile material for producing nanoparticles with different characteristics. Optimized nanoparticles were produced using desirability parameters. NVP-loaded PAG nanoparticles formulation showed 202.1 nm of particle size, 0.23 of PDI, -17.1 of zeta potential, 69.8 of encapsulation efficiency, and promoted modified drug release for 8 h. Here we show that PAG presents as a promising biopolymer for drug delivery systems.

Alendronate sodium-polymeric nanoparticles display low toxicity in gastric mucosal of rats and Ofcol II cells

The use of bisphosphonates constitutes the gold-standard therapy for the control and treatment of bone diseases. However, its long-term use may lead to gastric problems, which limits the treatment. Thus, this study aimed to formulate a nanostructured system with biodegradable polymers for the controlled release of alendronate sodium. The nanoparticles were characterized, and its gastric toxicity was investigated in rats. The synthesis process proved to be effective for encapsulating alendronate sodium, exhibiting nanoparticles with an average size of 51.02 nm and 98.5% of alendronate sodium incorporation. The release tests demonstrated a controlled release of the drug in 420 min, while the morphological analyzes showed spherical shapes and no apparent roughness. The biological tests demonstrated that the alendronate sodium nanoformulation reversed the gastric lesions, maintaining the normal levels of malondialdehyde and myeloperoxidase. Also, the encapsulated alendronate sodium showed no toxicity in murine osteoblastic cells, even at high concentrations.

Cashew Gum (Anacardium occidentale) as a Potential Source for the Production of Tocopherol-Loaded Nanoparticles: Formulation, Release Profile and Cytotoxicity

Every year, more than thirty thousand tons of Cashew gum (Anacardium occidentale, family: Anacardiaceae) are produced in Brazil; however, only a small amount is used for different applications in foodstuff and in pharmaceutical industries. As a raw material for the production of drug delivery systems, cashew gum is still regarded as an innovative compound worth to be exploited. In this work, cashew gum was extracted from the crude exudate of cashew tree employing four methodologies resulting in a light brown powder in different yields (40.61% to 58.40%). The total ashes (0.34% to 1.05%) and moisture (12.90% to 14.81%) were also dependent on the purification approach. FTIR spectra showed the typical bands of purified cashew gum samples, confirming their suitability for the development of a pharmaceutical product. Cashew gum nanoparticles were produced by nanoprecipitation resulting in particles of low polydispersity (<0.2) and an average size depending on the percentage of the oil. The zeta potential of nanoparticles was found to be below 20 mV, which promotes electrostatic stability. Encapsulation efficiencies were above 99.9%, while loading capacity increased with the increase of the percentage of the oil content of particles. The release of the oil from the nanoparticles followed the Korsmeyer–Peppas kinetics model, while particles did not show any signs of toxicity when tested in three distinct cell lines (LLC-MK2, HepG2, and THP-1). Our study highlights the potential added value of using a protein-, lignans-, and nucleic acids-enriched resin obtained from crude extract as a new raw material for the production of drug delivery systems.

Synthesis, characterization and use of enzyme cashew gum nanoparticles for biosensing applications

This research reports, for the first time, the immobilization of an enzyme - Rhus vernificera laccase - on cashew gum (CG) nanoparticles (NPs) and its application as a biological layer in the design and development of an electrochemical biosensor. Laccase-CG nanoparticles (LacCG-NPs) were prepared by the nanoprecipitation method and characterized by UV-Vis spectrophotometry, atomic force microscopy, scanning electron microscopy, attenuated total reflectance-Fourier-transform infrared spectroscopy, circular dichroism, cyclic voltammetry, and electrochemical impedance spectroscopy. The average size and stability of the NPs were predicted by DLS and zeta potential. The ATR-FTIR results clearly demonstrated an interaction between -NH and -OH groups to form LacCG-NPs. The average size found for LacCG-NPs was 280 ± 53 nm and a polydispersity index of 0.309 ± 0.08 indicated a good particle size distribution. The zeta potential shows a good colloidal stability. The use of a natural product to prepare the enzymatic nanoparticles, its easy synthesis and the immobilization efficiency should be highlighted. LacCG-NPs were successfully applied as a biolayer in the development of an amperometric biosensor for catechol detection. The resulting device showed a low response time (6 s), good sensitivity (7.86 μA μM^-1 cm^-2), wide linear range of 2.5 × 10^-7-2.0 × 10^-4 M, and low detection limit (50 nM).

Recent developments in biomolecule-based nanoencapsulation systems for antimicrobial delivery and biofilm disruption

Biomolecules are very attractive nanomaterial components, generally, due to their biocompatibility, biodegradability, abundance, renewability, and sustainability, as compared to other resources for nanoparticle-based delivery systems. Biomolecule-based nanoencapsulation and nanodelivery systems can be designed and engineered for antimicrobial cargos in order to surmount classical and current challenges, including the emergence of multi-drug resistant strains of microorganisms, the low effectiveness and limitations in the applicability of the present antimicrobials, and biofilm formation. This feature article highlights the recent applications and capabilities of biomacromolecule-based nanomaterials for the delivery and activity enhancement of antimicrobials, and disruption of biofilms. Unique properties of some nanomaterials, arising from specific biomacromolecules, were also emphasized. We expect that this review will be helpful to researchers in engineering new types of antimicrobial nanocarriers, hybrid particles and colloidal systems with tailored properties.

Polymeric Carriers Designed for Encapsulation of Essential Oils with Biological Activity

The article reviews the possibilities of encapsulating essential oils EOs, due to their multiple benefits, controlled release, and in order to protect them from environmental conditions. Thus, we present the natural polymers and the synthetic macromolecular chains that are commonly used as networks for embedding EOs, owing to their biodegradability and biocompatibility, interdependent encapsulation methods, and potential applicability of bioactive blend structures. The possibilities of using artificial intelligence to evaluate the bioactivity of EOs—in direct correlation with their chemical constitutions and structures, in order to avoid complex laboratory analyses, to save money and time, and to enhance the final consistency of the products—are also presented.

Cashew Gum Polysaccharide Nanoparticles Grafted with Polypropylene Glycol as Carriers for Diclofenac Sodium

This investigation focuses on the development and optimization of cashew gum polysaccharide (CGP) nanoparticles grafted with polypropylene glycol (PPG) as carriers for diclofenac sodium. The optimization of parameters affecting nanoparticles formulation was performed using a central composite rotatable design (CCRD). It was demonstrated that the best formulation was achieved when 10 mg of CGP was mixed with 10 μL of PPG and homogenized at 22,000 rpm for 15 min. The physicochemical characterization evidenced that diclofenac was efficiently entrapped, as increases in the thermal stability of the drug were observed. The CGP-PPG@diclofenac nanoparticles showed a globular shape, with smooth surfaces, a hydrodynamic diameter around 275 nm, a polydispersity index (PDI) of 0.342, and a zeta potential of -5.98 mV. The kinetic studies evidenced that diclofenac release followed an anomalous transport mechanism, with a sustained release up to 68 h. These results indicated that CGP-PPG nanoparticles are an effective material for the loading/release of drugs with similar structures to diclofenac sodium.

Calcium pectinate and hyaluronic acid modified lactoferrin nanoparticles loaded rhein with dual-targeting for ulcerative colitis treatment

Herein, dual-bioresponsive of Rhein (RH) in promoting colonic mucous damage repair and controlling inflammatory reactions were combined by the dual-targeting (intestinal epithelial cells and macrophages) oral nano delivery strategy for effective therapy of ulcerative colitis (UC). Briefly, two carbohydrates, calcium pectinate (CP) and hyaluronic acid (HA) were used to modify lactoferrin (LF) nanoparticles (NPs) to encapsulate RH (CP/HA/RH-NPs). CP layer make CP/HA/RH-NPs more stable and protect against the destructive effects of the gastrointestinal environment and then release HA/RH-NPs to colon lesion site. Cellular uptake evaluation confirmed that NPs could specifically target and enhance the uptake rate via LF and HA ligands. in vivo experiments revealed that CP/HA/RH-NPs significantly alleviated inflammation by inhibiting the TLR4/MyD88/NF-κB signaling pathway and accelerated colonic healing. Importantly, with the help of CP, this study was the first to attempt for LF as a targeting nanomaterial in UC treatment and offers a promising food-based nanodrug in anti-UC.

Poly(ε-caprolactone) grafted cashew gum nanoparticles as an epirubicin delivery system

Polysaccharide based copolymers have been the focus of several research, particularly for the development of drug delivery systems. This study reports on the preparation of nanoparticles from an amphiphilic copolymer obtained by the poly(ε-caprolactone) graft in the structure of cashew gum, via ring-opening polymerization. The synthesis of copolymers was confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The copolymers exhibit self-organization capability in water, with critical association concentration of 42 and 50 μg mL^-1. The nanoparticle hydrodynamic diameters (212 and 202 nm) revealed a decreasing trend with increasing poly(ε-caprolactone) graft percentage. Epirubicin was used as an anticancer drug model and incorporated into the nanoparticles. The encapsulation efficiency reached 50% and 5.0% drug load. Nanoparticles showed an epirubicin controlled release profile, with maximum release of 93.0 ± 4.0% in 72 h, as well as excellent biocompatibility, according to hemolysis and cytotoxicity assays.

Stimuli-responsive natural gums-based drug delivery systems for cancer treatment

Chemotherapy as the main cancer treatment method has non-specific effects and various side-effects. Accordingly, significant attempts have been conducted to enhance its efficacy through design and development of "smart" drug delivery systems (DDSs). In this context, natural gums, as a nice gift by the nature, can be exploited as stimuli-responsive DDSs for cancer treatment in part due to their renewability, availability, low cost, bioactivity, biocompatibility, low immunogenicity, biodegradability, and acceptable stability in both in vitro and in vivo conditions. However, some shortcomings (e.g., poor mechanical properties and high hydration rate) restrict their biomedical application ranges that can be circumvented through modification process (e.g., grafting of stimuli-responsive polymers or small molecules) to obtain tailored biomaterials. This review article aimed to compile the stimuli-responsive DDSs based on natural gums. In addition, different types of stimuli, the fundamental features of natural gums, as well as their chemical modification approaches are also shortly highlighted.

Synthesis and characterization of scaffolds produced under mild conditions based on oxidized cashew gums and carboxyethyl chitosan

This study describes the development of scaffolds based on carboxyethyl chitosan (CEC) and different oxidized cashew gums (CGOx) for tissue engineering (TE) applications. After the physico-chemical characterizations of CEC and CGOx (oxidation degree of 20, 35 and 50%), these macromolecules were used for producing the CGOx-CEC hydrogels through a Schiff base reaction, in the absence of any crosslinking agent. The CGOx-CEC scaffolds obtained after a freeze-drying process were characterized for their morphology, mechanical properties, swelling ability, degradation, and porosity. Those revealed to be highly porous (25-65%), and showed a stable swelling behavior, as well as degradation properties in the absence of enzymes. The use of the cashew gum with higher degree of oxidation led to scaffolds with higher crosslinking densities and increased compressive modulus. None of the hydrogels show cytotoxicity during the 14 days of incubation. Considering all the properties mentioned, these scaffolds are excellent candidates for soft tissue regeneration, owing to the use of eco-friendly starting materials and the easy tuning of their properties.

Cashew gum as a sol-gel precursor for green synthesis of nanostructured Ni and Co ferrites

The aim of this work consists in the use of cashew gum (Anacardium occidentale), a naturally occurring tropical specie from the Brazilian northeastern coast, for the synthesis of CoFe₂O₄ (CF) and NiFe₂O₄ (NF) nanoparticles. The structural, morphological and vibrational properties of nanoparticles were characterized by analytical and spectroscopic techniques such as X-ray diffraction (XRD), FTIR, Raman spectroscopy, TEM, SAED and TG. Magnetic properties were investigated through Mössbauer spectroscopy and DC magnetometry. The XRD results showed single phase nanoparticles with space group Fd-3m and crystallite size of 7.4 and 6.0 for CF and NF, respectively. TEM images showed agglomerated particles with mode sizes of 5.0 and 6.5 nm for CF and NF. SAED confirmed the crystalline spinel structure. The TGA and FTIR showed the presence of a carbonaceous material in the samples. FTIR and Raman spectroscopy demonstrated vibrational modes characteristic of metal‑oxygen bonds in the tetrahedral and octahedral sites. Magnetization measurements showed that both samples are superparamagnetic at 300 K. The Mössbauer spectra at 90 K showed the presence of single-phase CF and NF.

Thiolated okra chitosan nanoparticles: preparation and optimisation as intranasal drug delivery agents

AIM

The preparation of thiolated okra gum by use of full factorial design to optimise the reaction conditions.

METHODS

Thiolated gum was obtained by esterification optimised by full factorial design. The effect of varying the thiolated Okra concentration, chitosan concentration, pH, and stirring speed on particle size, entrapment efficiency and zeta potential was observed using Box-Behnken design.

RESULTS

Maximum yield and degree of substitution were obtained at reaction time of 152 min, 6.73 ml of thioglycolic acid and 70 °C of temperature. The optimised calculated parameters were thiolated okra concentrations of (0.07% w/v), chitosan concentration (0.05% w/v), pH (3), stirring speed (4430 rpm), which yielded nanoparticles of size 294.3 ± 0.3 nm, 43.57 ± 1.21% entrapment and 23.29 ± 2.3 mV of Zeta potential.

CONCLUSION

NPs were observed to be promising for brain targeting.

Microwave-initiated rapid synthesis of phthalated cashew gum for drug delivery systems

Chemical modification of polysaccharides is an important approach for their transformation into customized matrices that suit different applications. Microwave irradiation (MW) has been used to catalyze chemical reactions. This study developed a method of MW-initiated synthesis for the production of phthalated cashew gum (Phat-CG). The structural characteristics and physicochemical properties of the modified biopolymers were investigated by FTIR, GPC, ¹H NMR, relaxometry, elemental analysis, thermal analysis, XRD, degree of substitution, and solubility. Phat-CG was used as a matrix for drug delivery systems using benznidazole (BNZ) as a model drug. BNZ is used in the pharmacotherapy of Chagas disease. The nanoparticles were characterized by size, PDI, zeta potential, AFM, and in vitro release. The nanoparticles had a size of 288.8 nm, PDI of 0.27, and zeta potential of -31.8 mV. The results showed that Phat-CG has interesting and promising properties as a new alternative for improving the treatment of Chagas disease.

Occurrence and possible roles of polysaccharides in fungi and their influence on the development of new technologies

The article summarizes the roles of polysaccharides in the biology of fungi and their relationship in the development of new technologies. The comparative approach between the evolution of fungi and the chemistry of glycobiology elucidated relevant aspects about the role of polysaccharides in fungi. Also, based on the knowledge of fungal glycobiology, it was possible to address the development of new technologies, such as the production of new anti-tumor drugs, vaccines, biomaterials, and applications in the field of robotics. We conclude that polysaccharides activate pathways of apoptosis, secretion of pro-inflammatory substances, and macrophage, inducing anticancer activity. Also, the activation of the immune system, which opens the way for the production of vaccines. The development of biomaterials and parts for robotics is a promising and little-explored field. Finally, the article is multidisciplinary, with a different and integrated approach to the role of nature in the sustainable development of new technologies.

Modified chicha gum by acetylation for antimicrobial and antiparasitic applications: Characterization and biological properties

It was developed a material to act as an antimicrobial and antiparasitic agent through a modification reaction in the gum structure extracted from the plant Sterculia striata. This material was characterized, the oxidant activity was evaluated and the antimicrobial activity against Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium and Klebsiella pneumoniae was investigated, in addition to the effect against Leishmania amazonensis, testing its acute toxicity and its cytotoxicity in human cells. Characterization techniques proved the success of chemical modification. The modification led to an increase in antioxidant activity, with excellent antibacterial activity, reaching almost 100% inhibition for P. aeruginosa and S. Typhimurium, and inhibitory effect above 70% against L. amazonensis, with an affinity far superior to the parasite than macrophages. The derivative showed no acute toxicity, it was non-hemolytic, increased cell viability in macrophages and fibroblasts, and stimulated cell proliferation of keratinocytes, thus being a strong candidate to be used as an antimicrobial and antiparasitic agent in biomedical applications.

Hydrophobic Modification of Cashew Gum with Alkenyl Succinic Anhydride

Cashew gum (CG) shows promise of being useful as an agro-based raw material for the production of eco-friendly and biodegradable polymers. In this work, we modified this water-soluble polymer with alkenyl succinic anhydride in order to attach a hydrophobic group to it. The modification used two reagents: octenyl succinic anhydride and tetrapropenyl succinic anhydride. Reactions were conducted at 120 °C using dimethyl sulfoxide as a solvent, with conversions better than 88%. Samples with degrees of substitution (DS) between 0.02 and 0.20 were made. The resulting polymers were characterized using ¹H NMR, ¹³C NMR, FTIR, TGA, and GPC. The addition of the hydrophobe decreased the affinity of cashew gum for water absorption. Hydrophobically modified polysaccharides are often used as polymeric emulsifiers, thickeners, and compatibilizers; we anticipate that these new hydrophobically modified CGs may be used for the same applications.

Self-assembling cashew gum-graft-polylactide copolymer nanoparticles as a potential amphotericin B delivery matrix

Amphotericin B is an antibiotic used in the treatment of fungal disease and leishmania; however, it exhibits side effects to patients, hindering its wider application. Therefore, nanocarriers have been investigated as delivery systems for amphotericin B (AMB) in order to decrease its toxicity, besides increase bioavailability and solubility. Amphiphilic copolymers are interesting materials to encapsulate hydrophobic drugs such as AMB, hence copolymers of cashew gum (CG) and l-lactide (LA) were synthesized using two different CG:LA molar ratios (1:1 and 1:10). Data obtained revealed that copolymer nanoparticles present similar figures for particle sizes and zeta potentials; however, particle size of encapsulated AMB increases if compared to unloaded nanoparticles. The 1:10 nanoparticle sample has better stability although higher polydispersity index (PDI) if compared to 1:1 sample. High amphotericin (AMB) encapsulation efficiencies and low hemolysis were obtained. AMB loaded copolymers show lower aggregation pattern than commercial AMB solution. AMB loaded nanoparticles show antifungal activities against four C. albicans strains. It can be inferred that cashew gum/polylactide copolymers have potential as nanocarrier systems for AMB.

Self-Assembled Carbohydrate Polymers for Food Applications: A Review

The self-assembled natural and synthetic polymers are booming. However, natural polymers obtained from native or modified carbohydrate polymers (CPs), such as celluloses, chitosan, glucans, gums, pectins, and starches, have had special attention as raw material in the manufacture of self-assembled polymer composite materials having several forms: films, hydrogels, micelles, and particles. The easy manipulation of the architecture of the CPs, as well as their high availability in nature, low cost, and being sustainable and green polymers have been the main positive points in the use of them for different applications. CPs have been used as building blocks for composite structures, and their easy orientation and ordering has given rise to self-assembled CPs (SCPs). These macromolecules have been little studied for food applications. Nonetheless, their research has grown mainly in the last 5 years as encapsulated food additive wall materials, food coatings, and edible films. The multifaceted properties (systems sensitive to pH, temperature, ionic strength, types of ions, mechanical force, and enzymes) of these devices are leading to the development of advanced food materials. This review article focused on the analysis of SCPs for food applications in order to encourage other research groups for their preparation and implementation.

Development of Composite Scaffolds Based on Cerium Doped-Hydroxyapatite and Natural Gums-Biological and Mechanical Properties

Hydroxyapatite (HAp) is a ceramic material composing the inorganic portion of bones. Ionic substitutions enhance characteristics of HAp, for example, calcium ions (Ca²⁺) by cerium ions (Ce³⁺). The use of HAp is potentialized through biopolymers, cashew gum (CG), and gellan gum (GG), since CG/GG is structuring agents in the modeling of structured biocomposites, scaffolds. Ce-HApCG biocomposite was synthesized using a chemical precipitation method. The obtained material was frozen (–20 °C for 24 h), and then vacuum dried for 24 h. The Ce-HApCG was characterized by X-Ray diffractograms (XRD), X-ray photoemission spectra (XPS), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and energy dispersive spectroscopy (EDS). XRD and FTIR showed that Ce-HApCG was successfully synthesized. XRD showed characteristic peaks at 2θ = 25.87 and 32.05, corresponding to the crystalline planes (0 0 2) and (2 1 1), respectively, while phosphate bands were present at 1050 cm⁻¹ and 1098 cm⁻¹, indicating the success of composite synthesis. FESEM showed pores and incorporated nanostructured granules of Ce-HApCG. The mechanical test identified that Ce-HApCG has a compressive strength similar to the cancellous bone’s strength and some allografts used in surgical procedures. In vitro tests (MTT assay and hemolysis) showed that scaffold was non-toxic and exhibited low hemolytic activity. Thus, the Ce-HApCG has potential for application in bone tissue engineering.

Gum-based nanocarriers for the protection and delivery of food bioactive compounds

Gums, which for the most part are water-soluble polysaccharides, can interact with water to form viscous solutions, emulsions or gels. Their desirable properties, such as flexibility, biocompatibility, biodegradability, availability of reactive sites for molecular interactions and ease of use have led to their extremely large and broad applications in formation of nanostructures (nanoemulsions, nanoparticles, nanocomplexes, and nanofibers) and have already served as important wall materials for a variety of nano encapsulated food ingredients including flavoring agents, vitamins, minerals and essential fatty acids. The most common gums used in nano encapsulation systems include Arabic gum, carrageenan, xanthan, tragacanth plus some new sources of non-traditional gums, such as cress seed gum and Persian/or Angum gum identified as potential building blocks for nanostructured systems. New preparation techniques and sources of non-traditional gums are still being examined for commercialization in the food nanotechnology area as low-cost and reproducible sources. In this study, different nanostructures of gums and their preparation methods have been discussed along with a review of gum nanostructure applications for various food bioactive ingredients.

Acetylated cashew gum-based nanoparticles for the incorporation of alkaloid epiisopiloturine

The natural alkaloid epiisopiloturine has recently become the focus of study for various medicinal properties, particularly for its anti-inflammatory and antischistosomal effect. The incorporation of active molecules in natural polymeric matrices has garnered increasing interest during recent decades. A new derivative of cashew gum successfully obtained by gum acetylation has shown great potential as a carrier in controlled drug release systems. In this work, epiisopiloturine was encapsulated in acetylated cashew gum nanoparticles in order to increase solubility and allow slow release, whereas the morphology results were supported by computer simulations. The particles were produced under a variety of conditions, and thoroughly characterized using light scattering and microscopic techniques. The particles were spherical and highly stable in solution, and showed drug incorporation at high levels, up to 55% efficiency. Using a dialysis-based in vitro assay, these particles were shown to release the drug via a Fickian diffusion mechanism, leading to gradual drug release over approximately 6 h. These nanoparticles show potential for the use as drug delivery system, while studies on their potential anti-inflammatory action, as well as toxicity and efficacy assays would need to be performed in the future to confirm their suitability as drug delivery candidates.

Solvent-free synthesis of acetylated cashew gum for oral delivery system of insulin

Cashew gum (CG) is a biopolymer that presents a favorable chemical environment for structural modifications, which leads to more stable and resistant colloidal systems. The gum was subjected to an acetylation reaction using a fast, simple, solvent-free and low cost methodology. The derivative was characterized by infrared and NMR spectroscopy, elemental analysis, coefficient of solubility and zeta potential. The modified biopolymer was used as a platform for drug delivery systems using insulin as a model drug. Nanoparticles were developed through the technique of polyelectrolytic complexation and were characterized by size, surface charge, entrapment efficiency and gastrointestinal release profile. The nanoparticles presented size of 460 nm with a 52.5% efficiency of entrapment of insulin and the electrostatic stabilization was suggested by the zeta potential of + 30.6 mV. Sustained release of insulin was observed for up to 24 h. The results showed that acetylated cashew gum (ACG) presented potential as a vehicle for sustained oral insulin release.

In Situ Synthesis of Silver Nanoparticles in a Hydrogel of Carboxymethyl Cellulose with Phthalated-Cashew Gum as a Promising Antibacterial and Healing Agent

Silver nanoparticles have been shown to possess considerable antibacterial activity, but in vivo applications have been limited due to the inherent, but low, toxicity of silver. On the other hand, silver nanoparticles could provide cutaneous protection against infection, due to their ability to liberate silver ions via a slow release mechanism, and their broad-spectrum antimicrobial action. Thus, in this work, we describe the development of a carboxymethyl cellulose-based hydrogel containing silver nanoparticles. The nanoparticles were prepared in the hydrogel in situ, utilizing two variants of cashew gum as a capping agent, and sodium borohydride as the reducing agent. This gum is non-toxic and comes from a renewable natural source. The particles and gel were thoroughly characterized through using rheological measurements, UV-vis spectroscopy, nanoparticles tracking analysis, and transmission electron microscopy analysis (TEM). Antibacterial tests were carried out, confirming antimicrobial action of the silver nanoparticle-loaded gels. Furthermore, rat wound-healing models were used and demonstrated that the gels exhibited improved wound healing when compared to the base hydrogel as a control. Thus, these gels are proposed as excellent candidates for use as wound-healing treatments.

Purification of poly(acrylic acid) using a membrane ultra-filtration unit in flow

We have developed methodology to synthesise aqueous soluble polymers such as poly(acrylic acid) in flow, enabling access to a variety of molecular weights.