Synthesis and characterization of pectin derivative with antitumor property against Caco-2 colon cancer cells

Quantitative analysis of loxoprofen sodium loaded microspheres comprising pectin and its thiolated conjugates: In-vivo evaluation of their sustained release behavior

Continuous use of oral NSAIDs can damage mucosal membrane, which results in decreased bioavailability and non-compliance with the therapy. But the use of sustained release drug delivery systems might offer a solution. Objective was to synthesize mucoadhesive SR microspheres by using different combinations of pectin (PEC) and its thiolated derivative (T-PEC3100) for improved loxoprofen (LS) permeation. Thiolated pectin (T-PEC) was synthesized by the esterification method using thioglycolic acid. Thiolation was confirmed by thiol group quantification and charring point determination. Further characterization was done by Fourier Transform Infrared spectroscopy (FTIR), and Scanning electron microscopy (SEM). Ex-vivo mucoadhesion study was performed to confirm the improved characteristics. Microspheres (MS) were prepared using different ratios of PEC/T-PEC by solvent evaporation method and their particle size and surface morphology were evaluated. Mucus permeation study was carried out using the trans-well plate method. Sustained release behavior of prepared microspheres was investigated through the edema inhibition method in albino rats. T-PEC3100 was considered the optimum formulation for further evaluation and contained maximum thiol group content. FTIR spectra showed a characteristic peak of -SH and charring point was also changed considerably confirming the successful thiolation of PEC. SEM results showed spherical microspheres in the size range of 2-10 μm. Thiol-rich formulation of MS exhibited more than 80 % release after 12 h and maximum absorbable dose (MAD) was calculated as 400 μg % inhibition of edema in MS treated group was slowly attained initially but the reduction in inflammation was detected even after 24 h as compared to control group. Promising results from In-vivo edema inhibition study suggest the possible use of these thiolated MS in formulating sustained release formulation for arthritis.

Inherited Structure Properties of Larch Arabinogalactan Affected via the TEMPO/NaBr/NaOCl Oxidative System

Arabinogalactan (AG), extracted from larch wood, is a β-1,3-galactan backbone and β-1,6-galactan side chains with attached α-1-arabinofuranosyl and β-1-arabinopyranosyl residues. Although the structural characteristics of arabinogalactan II type have already been studied, its functionalization using 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) oxidation remains a promising avenue. In this study, the oxidation of AG, a neutral polysaccharide, was carried out using the TEMPO/NaBr/NaOCl system, resulting in polyuronides with improved functional properties. The oxidation of AG was controlled by analyzing portions of the reaction mixture using spectrophotometric and titration methods. To determine the effect of the TEMPO/NaBr/NaOCl system, air-dried samples of native and oxidized AG were studied by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy, as well as by gel permeation chromatography. Compounds that model free (1,1-diphenyl-2-picrylhydrazyl (DPPH)) and hydroxyl radicals (iron(II) sulfate, hydrogen peroxide, and salicylic acid) were used to study the antioxidant properties. It was found that, in oxidized forms of AG, the content of carboxyl groups increases by 0.61 mmol compared to native AG. The transformation of oxidized AG into the H+ form using a strong acid cation exchanger leads to an increase in the number of active carboxyl groups to 0.76 mmol. Using FTIR spectroscopy, characteristic absorption bands (1742, 1639, and 1403 cm-1) were established, indicating the occurrence of oxidative processes with a subsequent reduction in the carboxyl group. The functionality of AG was also confirmed by gel permeation chromatography (GPC), which is reflected in an increase in molecular weights (up to 15,700 g/mol). A study of the antioxidant properties of the oxidized and protonated forms of AG show that the obtained antioxidant activity (AOA) values are generally characteristic of polyuronic acids. Therefore, the TEMPO oxidation of AG and other neutral polysaccharides can be considered a promising approach for obtaining compounds with the necessary controlled characteristics.

Therapeutic Potential of Pectin and Its Derivatives in Chronic Diseases

Non-communicable diseases (NCDs) are described as a collection of chronic diseases that do not typically develop from an acute infection, have long-term health effects, and frequently require ongoing care and therapy. These diseases include heart disease, stroke, cancer, chronic lung disease, neurological diseases, osteoporosis, mental health disorders, etc. Known synthetic drugs for the treatment or prevention of NCDs become increasingly dangerous over time and pose high risks due to side effects such as hallucination, heart attack, liver failure, etc. As a result, scientists have had to look for other alternatives that are natural products and that are known to be less detrimental and contain useful bioactive compounds. The increasing understanding of the biological and pharmacological significance of carbohydrates has helped to raise awareness of their importance in living systems and medicine, given they play numerous biological roles. For example, pectin has been identified as a class of secondary metabolites found in medicinal plants that may play a significant role in the treatment and management of a variety of NCDs. Pectin is mainly made of homogalacturonan, which is a linear polymer composed primarily of D-galacturonic acid units (at least 65%) linked in a chain by α-(1,4)-glycosidic linkages. There are also modified pectins or derivatives that improve pectin's bioavailability. Pectin is found in the cell walls of higher plants (pteridophytes, angiosperms, and gymnosperms), particularly in the middle lamella of the plant material. Citrus pectin is used in various industries. This article compiles information that has been available for years about the therapeutic importance of pectin in chronic diseases, different modes of pectin extraction, the chemistry of pectin, and the potency of pectin and its derivatives.

Modification methods, biological activities and applications of pectin: A review

Pectin is a complex and functionally rich natural plant polysaccharide that is widely used in food, medical, and cosmetic industries. It can be modified to improve its properties and expand its applications. Modification methods for natural pectin can be divided into physical, chemical, enzymatic, and compound methods. Different modification methods can result in modified pectins (MPs) exhibiting different physicochemical properties and biological activities. The objectives of this paper were to review the various pectin modification methods explored over the last decade, compare their differences, summarize the impact of different modification methods on the biological activity and physicochemical properties of pectin, and describe the applications of MPs in food and pharmaceutical fields. Finally, suggestions and perspectives for the development of MPs are discussed. This review offers a theoretical reference for the rational and efficient processing of pectin and the expansion of its applications.

Novel Gold Nanorods@Thiolated Pectin on the Killing of HeLa Cells by Photothermal Ablation

Gold nanorods (AuNRs) have attracted attention in the field of biomedicine, particularly for their potential as photothermal agents capable of killing tumor cells by photothermic ablation. In this study, the synthesis of novel AuNRs stabilized with thiolated pectin (AuNR@SH-PEC) is reported. To achieve this, thiolated pectin (SH-PEC) was obtained by chemically binding cysteamine motifs to the pectin backbone. The success of the reaction was ascertained using FTIR-ATR. Subsequently, the SH-PEC was used to coat and stabilize the surface of AuNRs (AuNR@SH-PEC). In this context, different concentrations of SH-PEC (0.25, 0.50, 1.0, 2.0, 4.0, and 8.0 mg/mL) were added to 0.50 mL of AuNRs suspended in CTAB, aiming to determine the experimental conditions under which AuNR@SH-PEC maintains stability. The results show that SH-PEC effectively replaced the CTAB adsorbed on the surface of AuNRs, enhancing the stability of AuNRs without affecting their optical properties. Additionally, scanning electron and atomic force microscopy confirmed that SH-PEC is adsorbed into the surface of the AuNRs. Importantly, the dimension size (60 × 15 nm) and the aspect ratio (4:1) remained consistent with those of AuNRs stabilized with CTAB. Then, the photothermal properties of gold nanorods were evaluated by irradiating the aqueous suspension of AuNR@SH-PEC with a CW laser (808 nm, 1 W). These results showed that photothermal conversion efficiency is similar to the photothermal conversion observed for AuNR-CTAB. Lastly, the cell viability assays confirmed that the SH-PEC coating enhanced the biocompatibility of AuNR@SH-PEC. Most important, the viability cell assays subjected to laser irradiation in the presence of AuNR@SH-PEC showed a decrease in the cell viability relative to the non-irradiated cells. These results suggest that AuNRs stabilized with thiolated pectin can potentially be exploited in the implementation of photothermal therapy.

Pectin a multifaceted biopolymer in the management of cancer: A review

This review article focuses on the multifaceted roles of pectin in cancer management, namely as an oncotherapeutic delivery vehicle and a pharmacological agent. Over the past decades, the potential of pectin as a novel therapeutical agent for the prevention and/or management of cancer has gained increasing interest. Pectin has been found to modulate different mechanisms involved in the onset and progression of carcinogenesis, such as galectin-3 inhibition, caspase-3-induced apoptosis, and autophagy. Elucidating the structure-activity relationship provides insight into the relationship between the structure of pectin and different mechanism/s. The bioactivity of pectin, with respect to its structure, was critically discussed to give a better insight of the relationship between the structure of the extracted pectin and the observed bioactive effects. The rhamnogalacturonan I part of the pectin chain was found to bind to galectin-3, associated with several cancer hallmarks. The anti-inflammatory and antioxidant potential of pectin were also described. The roles of pectin as a treatment enhancer and a drug delivery vehicle for oncotherapeutics were critically defined. The scientific findings presented in this paper are expected to highlight the potential and role of pectin recovered from various plant sources in preventing and managing cancer.

Spectroscopic Analyses Highlight Plant Biostimulant Effects of Baker's Yeast Vinasse and Selenium on Cabbage through Foliar Fertilization

The main aim of this study is to find relevant analytic fingerprints for plants' structural characterization using spectroscopic techniques and thermogravimetric analyses (TGAs) as alternative methods, particularized on cabbage treated with selenium-baker's yeast vinasse formulation (Se-VF) included in a foliar fertilizer formula. The hypothesis investigated is that Se-VF will induce significant structural changes compared with the control, analytically confirming the biofortification of selenium-enriched cabbage as a nutritive vegetable, and particularly the plant biostimulant effects of the applied Se-VF formulation on cabbage grown in the field. The TGA evidenced a structural transformation of the molecular building blocks in the treated cabbage leaves. The ash residues increased after treatment, suggesting increased mineral accumulation in leaves. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) evidenced a pectin-Iα-cellulose structure of cabbage that correlated with each other in terms of leaf crystallinity. FTIR analysis suggested the accumulation of unesterified pectin and possibly (seleno) glucosinolates and an increased network of hydrogen bonds. The treatment with Se-VF formulation induced a significant increase in the soluble fibers of the inner leaves, accompanied by a decrease in the insoluble fibers. The ratio of soluble/insoluble fibers correlated with the crystallinity determined by XRD and with the FTIR data. The employed analytic techniques can find practical applications as fast methods in studies of the effects of new agrotechnical practices, while in our particular case study, they revealed effects specific to plant biostimulants of the Se-VF formulation treatment: enhanced mineral utilization and improved quality traits.

Dispersion and weak retardation performance of sulfate-based starch maleic acid monoesters in cement

To reduce the influence of a sulfate-based starch water-reducing agent on the setting time of cement, a novel starch-based water-reducing agent, namely sulfate-based starch maleic acid monoester (SAMAS), was designed to adjust its hydrophilicity by maleic acid monoester. Gel permeation chromatography, Fourier transform infrared spectroscopy, and ¹H NMR nuclear magnetic resonance spectroscopy were used to characterize the prepared SAMAS, while Zeta potential, UV-Vis absorption, X-ray photoelectron spectroscopy, X-ray diffraction, cement paste fluidity, and setting time measurements were conducted to investigate its dispersion performance, retardation performance, adsorption behavior, and mechanism of action. SAMAS exhibited good dispersion performance and did not significantly prolong the setting time of the cement. In addition, the dispersion performance of SAMAS was found to depend mainly on steric hindrance, and its weak retardation performance originated from the hydrophilic regulation of the maleic acid monoester groups, which ensures the normal progress of the cement hydration reaction by hindering the formation of a hydration film.

Novel pectin-based nanocomposite film for active food packaging applications

Novel pectin-based films reinforced with crystalline nanocellulose (CNC) and activated with zinc oxide nanoparticles (ZnO NPs) were prepared by solvent-casting method. Film ingredients enhanced UV-blocking, thermal, and antibacterial properties of active films against well-known foodborne pathogens. Optimal active films exhibited higher mechanical, water vapor barrier properties compared to pristine pectin films. SEM confirmed the even distribution of CNC and ZnO NPs in pectin matrix and their interactions were proven using FTIR. Wrapping hard cheese samples artificially contaminated with Staphylococcus aureus and Salmonella enterica with the ternary nanocomposite film at 7 °C for 5 days significantly reduced the total population counts by at least 1.02 log CFU/g. Zn2+ migrating to wrapped cheese samples was below the specific limit (5 mg/kg), confirming their safety for food contact. Overall, ZnO/CNC/pectin nanocomposite films represent promising candidates for active food packaging as safe, eco-friendly alternatives for synthetic packaging materials.

Enhanced interfacial interaction between modified cellulose nanocrystals and epoxidized natural rubber via ultraviolet irradiation

This study aims at evaluating the reinforcement of cellulose nanocrystals (CNCs) in epoxidized natural rubber (ENR). Both CNCs and maleic anhydride-modified CNCs (M-CNCs) were prepared from Napier grass stems and characterized by various techniques (e.g., TEM, FTIR, TGA, etc.). They were incorporated into ENR latex at various loadings prior to casting, and then curing by ultraviolet (UV) irradiation. Mechanical properties of the ENR vulcanizates were finally investigated. Results revealed that the prepared CNCs had an average diameter and length of 5 nm and 428 nm, respectively. After modification, M-CNCs contained double bonds in maleate units, which could react with ENR to form covalent bonds under UV irradiation through a proposed mechanism. Regardless of the filler type, mechanical properties including hardness, modulus, and tensile strength, increased considerably with increasing filler loading. At the same filler loading, M-CNCs exhibited greater reinforcement than CNCs due to the enhanced rubber–filler interaction.

The Influence of Extraction Conditions on the Yield and Physico-Chemical Parameters of Pectin from Grape Pomace

Grape pomace is one of the most abundant by-products generated from the wine industry. This by-product is a complex substrate consisted of polysaccharides, proanthocyanidins, acid pectic substances, structural proteins, lignin, and polyphenols. In an effort to valorize this material, the present study focused on the influence of extraction conditions on the yield and physico-chemical parameters of pectin. The following conditions, such as grape pomace variety (Fetească Neagră and Rară Neagră), acid type (citric, sulfuric, and nitric), particle size intervals (<125 µm, ≥125−<200 µm and ≥200−<300 µm), temperature (70, 80 and 90 °C), pH (1, 2 and 3), and extraction time (1, 2, and 3 h) were established in order to optimize the extraction of pectin. The results showed that acid type, particle size intervals, temperature, time, and pH had a significant influence on the yield and physico-chemical parameters of pectin extracted from grape pomace. According to the obtained results, the highest yield, galacturonic acid content, degree of esterification, methoxyl content, molecular, and equivalent weight of pectin were acquired for the extraction with citric acid at pH 2, particle size interval of ≥125−<200 µm, and temperature of 90 °C for 3 h. FT-IR analysis confirmed the presence of functional groups in the fingerprint region of identification for polysaccharide in the extracted pectin.

Green nanofiber mat from HLM-PVA-Pectin (Hibiscus leaves mucilage-polyvinyl alcohol-pectin) polymeric blend using electrospinning technique as a novel material in wound-healing process

The present work is focused on fabrication of novel nanofiber (NF) mat as wound-healing scaffold using blends of novel combination of Hibiscus rosa-sinensis leaves mucilage (HLM)-Polyvinyl alcohol (PVA)-Pectin, which was never reported previously. Different ratios of the polymeric blends were electrospun by setting different parameters to achieve best possible electrospun nanofiber mat which was later crosslinked by glutaraldehyde vapor. The optimized formulation of nanofiber mat was characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The crosslinked sample was evaluated for its efficacy in wound healing using Swiss albino mice model, where rapid healing of excised wound was observed with faster epithelization in test mice group than control mice within a period of 8 days. The hemolysis test with optimized crosslinked nanofiber mat CrNF(S7-CL) indicated it to be hemo-compatible. There were no traces of optimized CrNF(S7-CL) when placed under the skin hypodermis in test mice groups revealing its biodegradable nature. The degradation pattern of CrNF(S7-CL) in soil reflects its eco-friendly behavior. Thus, the prepared nanofiber grade CrNF(S7-CL) can be considered as a novel material for faster wound healing and can also be explored for other biomedical applications.

Anti-Cancer Pectins and Their Role in Colorectal Cancer Treatment

A class of plant polysaccharides, pectin is known to display several medicinal properties including in cancer. There is some evidence that pectin from some fruits can reduce the severity of colorectal cancer (CRC) due to its antiproliferative, anti-inflammatory, antimetastatic and pro-apoptotic properties. Pectin fermentation in the colon induces antiproliferative activity via butyrate. Research also showed that pectin acts as a potent inducer of programmed cell death and cell-cycle arrest, thereby selectively targeting cancer cells. Pectin can limit oxidative stress to maintain cellular homeostasis while increasing reactive oxygen species damage to activate cancer cell death. Pectin regulates various signaling cascades, e.g., signal transduction and transcriptional activator and mitogen-activated protein kinase signaling, that contribute to its anticancer activity. By curbing inflammation-activated signaling and bolstering immune-protective mechanisms pectin can eradicate CRC. Due to its chemical structure, pectin can also inhibit galectin-3 and suppress tumor growth and metastasis. Prior reports also suggested that pectin is beneficial to use alongside the CRC standard care. Pectin can increase sensitivity to conventional CRC drugs, alleviate unwanted side effects and reduce drug resistance. Although some preclinical studies are promising, early clinical trials are showing some evidence for pectin's efficacy in tumor growth inhibition and preventing metastasis in some cancers; however, the clinical use of pectin in CRC therapy is not yet well established. Further studies are needed to confirm the efficacy of pectin treatment as a valid clinical therapy for CRC in humans.

Dialdehyde pectin-crosslinked and hirudin-loaded decellularized porcine pericardium with improved matrix stability, enhanced anti-calcification and anticoagulant for bioprosthetic heart valves

To conveniently and effectively cure heart valve diseases or defects, combined with transcatheter valve technology, bioprosthetic heart valves (BHVs) originated from the decellularized porcine pericardium (D-PP) have been broadly used in clinics. Unfortunately, most clinically available BHVs crosslinked with glutaraldehyde (GA) were challenged in their long-term tolerance, degenerative structural changes, and even failure, owing to the synergistic impact of multitudinous elements (cytotoxicity, calcification, immune responses, etc.). In this work, dialdehyde pectin (AP) was prepared by oxidizing the o-dihydroxy of pectin with sodium periodate. Hereafter, the AP-fixed PP model was obtained by crosslinking D-PP with AP with high aldehyde content (6.85 mmol g^-1), for acquiring excellent mechanical properties and outstanding biocompatibility. To further improve the hemocompatibility of the AP-fixed PP, a natural and specific inhibitor of thrombin (hirudin) was introduced to achieve surface modification of the AP-fixed PP. The feasibility of crosslinking and functionalizing AP-fixed PP, which was a potential leaflet material of BHVs, was exhaustively and systematically evaluated. In vitro studies found that hirudin-loaded and AP-fixed PP (AP + Hirudin-PP) had synchronously achieved effective fixation of collagen, highly effective anticoagulation, and good HUVECs-cytocompatibility. In vivo results revealed that the AP + Hirudin-PP specimens recruited the minimum immune cells in the implantation experiment, and also presented an excellent anti-calcification effect. Overall, AP + Hirudin-PP was endowed with competitive collagen stability (compared with GA-fixed PP), excellent hemocompatibility, good HUVECs-cytocompatibility, low immunogenicity and outstanding anti-calcification, suggesting that AP + Hirudin-PP might be a promising alternative to GA-fixed PP and exhibited a bright prospect in the clinical applications of BHVs.

Recent advances in utilization of pectins in biomedical applications: a review focusing on molecular structure-directing health-promoting properties

The numerous health benefits of pectins justify their inclusion in human diets and biomedical products. This review provides an overview of pectin extraction and modification methods, their physico-chemical characteristics, health-promoting properties, and pharmaceutical/biomedical applications. Pectins, as readily available and versatile biomolecules, can be tailored to possess specific functionalities for food, pharmaceutical and biomedical applications, through judicious selection of appropriate extraction and modification technologies/processes based on green chemistry principles. Pectin's structural and physicochemical characteristics dictate their effects on digestion and bioavailability of nutrients, as well as health-promoting properties including anticancer, immunomodulatory, anti-inflammatory, intestinal microflora-regulating, immune barrier-strengthening, hypercholesterolemia-/arteriosclerosis-preventing, anti-diabetic, anti-obesity, antitussive, analgesic, anticoagulant, and wound healing effects. HG, RG-I, RG-II, molecular weight, side chain pattern, and degrees of methylation, acetylation, amidation and branching are critical structural elements responsible for optimizing these health benefits. The physicochemical characteristics, health functionalities, biocompatibility and biodegradability of pectins enable the construction of pectin-based composites with distinct properties for targeted applications in bioactive/drug delivery, edible films/coatings, nano-/micro-encapsulation, wound dressings and biological tissue engineering. Achieving beneficial synergies among the green extraction and modification processes during pectin production, and between pectin and other composite components in biomedical products, should be key foci for future research.

Novel light-driven functional AgNPs induce cancer death at extra low concentrations

The current study is aimed at preparing light-driven novel functional AgNPs- bio-hydrogel and evaluating anticancer potency against human melanoma cells. With an average size of 16-18 nm, the hydrogel nano-silver particle composite (AgNPs@C_MA_O) was synthesized using a soft white LED approach and analyzed by UV-Vis, DLS, FTIR, X-ray, SEM-EDX and TEM techniques. The anticancer activity of the obtained novel functionalized AgNPs@C_MA_O was tested in-vitro in the A375 melanoma cell line. Dose-response analysis showed that AgNPs at 0.01 mg/mL and 0.005 mg/mL doses reduced the viability of A375 cells by 50% at 24 and 48-h time-points, respectively. A375 cells treated with AgNPs@C_MA_O for 24 h at IC50 displayed abnormal morphology such as detachment edges and feet, shrinkage, membrane damage, and the loss of contact with adjacent cells. Our work is the first study showing that non-ionizing radiation mediated biofunctionalized AgNPs have an anti-tumoral effect at such a low concentration of 0.01 mg/mL. Our approach of using harmless wLED increased synergy between soft biopolymer compounds and AgNPs, and enhanced anticancer efficiency of the AgNPs@C_MA_O biohydrogel. Ultimately, the AgNPs accessed through the use of the wLED approach in colloidal syntheses can open new applications and combinatorial advanced cancer treatments and diagnostics.

In silico design and pharmacological evaluation of conjugates of atenolol with modified saccharide for cardiovascular targeting

Amongst a wide range of biological macromolecules, saccharides exhibit the potential to be specifically recognized by cell-surface receptors and hence can be utilized as ligands in targeted drug delivery. The current study aims to use saccharides viz. Galactose, Pectin and Chitosan to improve targeting of Atenolol by oxalyl chloride mediated grafting. Conjugates were engineered by grafting Atenolol, a cardiovascular agent with the modified saccharide units. The conjugates were characterized by FTIR, DSC and ¹H NMR study. Drug release analysis and cellular uptake study was carried out using H9c2 cell lines which represent that concentration of drug in cells treated with all atenolol-saccharide conjugates is enhanced by almost two-folds in comparison with cells treated with atenolol solution. Thus cell line study confers the evidence of selective cardiac delivery. No significant cytotoxicity was observed in case of all synthesized conjugates in the Brine shrimp lethality bioassay. Possible binding of the developed conjugates with the GLUT-4 receptors was assessed by in silico analysis using homology model developed by Swiss Model server. Hence it was concluded that the application of these conjugates with saccharides in selective cardiovascular drug delivery can be a promising approach to increase bioavailability, minimize drug loss by degradation and prevent harmful side effects by increasing specific cell targeting.

Chemical Pretreatments on Residual Cocoa Pod Shell Biomass for Bioethanol Production

Cocoa pod shell is an essential agricultural residue in Ecuador, and this study addressed its potential valorization for bioethanol production. For this, three types of pretreatments, acid, alkaline, and autohydrolysis, were applied to pod shells from two different cocoa types, national and CCN-51. to remove the lignin. Untreated and treated biomasses were characterized by composition, thermal stability, Fourier transformed infrared spectroscopy (FITR), and scanning electron microscopy (SEM). The treated biomass was then enzymatically hydrolyzed with cellulase. Reducing sugars were quantified after pretreatments and enzymatic hydrolysis, and the pretreatment liquors and the enzymatic hydrolysates were subjected to alcoholic fermentation with Saccharomyces cerevisiae. There were substantial differences in composition between both biomasses, particularly in lignin content, with national cocoa having the lowest values. All pretreatment conditions had significant effects on biomass composition, structure, and thermal properties. After alkaline pretreatment, the biomass presented the highest cellulose and lowest lignin contents, resulting in the highest reducing sugar concentration in the pretreatment liquor. The highest lignin content was found after the acid pretreatment, which resulted in low, reducing sugar concentrations. Autohydrolysis produced similar results as the acid pretreatment; however, it resulted in the highest sugar concentration after enzymatic hydrolysis, while the acid-treated sample had negligible levels. After fermentation, there were no differences in productivity among the pretreatment liquors, but autohydrolysis had the largest ethanol yield. In the hydrolysates, it was also autohydrolysis that resulted in higher productivity and yield. Thus, there is an indication of the formation of inhibitors, both enzymatic activity and ethanol production, in the acid and alkaline pretreatments, and this should be tackled in future research. Nonetheless, given the crucial changes observed in biomass, we believe that cocoa pod shell pretreatment has potential for the generation of reducing sugars that could be further used in different bioprocesses, nor only bioethanol production.

Cashew apple pectin as a carrier matrix for mangiferin: Physicochemical characterization, in vitro release and biological evaluation in human neutrophils

In this work, cashew apple pectin (CP) of the species Anacardium occidentale L. was used as an encapsulation matrix for hydrophobic drugs. The model drug chosen was mangiferin (Mf), a glycosylated C-xanthone which has antioxidant properties but low solubility in aqueous medium. CP (1-100 μg mL^-1) was not toxic to human neutrophils and also did not significantly interfere with the pro-inflammatory mechanism of these cells in the concentration range of 12.5 and 100 μg mL^-1. The results are promising because they show that pectin encapsulated mangiferin after spray drying presented an efficiency of 82.02%. The results obtained in the dissolution test, simulating the release of mangiferin in the gastrointestinal tract (pH 1.2, 4.6 and 6.8) and using Franz diffusion cells (pH 7.4), showed that cashew pectin may be a promising vehicle in prolonged drug delivery systems for both oral and dermal applications.

Development of composite hydrogel based on hydroxyapatite mineralization over pectin reinforced with cellulose nanocrystal

Hydrogels based on pectin and cellulose nanocrystals (CNC) were used in our study to nucleation and growth of hydroxyapatite (HAp) by the biomimetic method. In this study, we evaluated the direct impact of the different percentages of CNC on pectin hydrogel and the influence of HAp obtained through two methods. CNC were obtained from HCl hydrolysis following chemical functionalization through vinyl groups. The percentage of CNC positively induces thermal stability, mechanical properties and HAp mineralization from biomimetic using simulated body fluid (1.5 SBF). Hydrogels with 5% of CNC showed a higher amount of HAp immersed for 14 days, about 28% of HAp. The obtained hydrogels were compared with hydrogels containing 20% of HAp nanoparticles obtained by chemical precipitation. Biocompatibility of the hydrogels was evaluated by cell viability using fibroblasts (L929). In general, the hydrogels obtained through the biomimetic method show slightly larger biocompatibility compared to the hybrid hydrogels obtained from chemical precipitation.

Synthesis and characterization of thermo/pH-sensitive pectin-graft-poly(dimethylaminoethyl methacrylate) coated magnetic nanoparticles

Herein, thermo- and pH-sensitive pectin-graft-poly(dimethylaminoethyl methacrylate) copolymer-coated magnetic nanoparticles were synthesized via a green and rapid synthetic approach based on microwave irradiation. Firstly, a novel thermo- and pH-sensitive pectin-graft-poly(dimethylaminoethyl methacrylate) copolymer (Pec-g-PolyDMAEMA) was synthesized and then, Pec-g-PolyDMAEMA based magnetic nanoparticles (Pec-g-PolyDMAEMA@Fe₃O₄) were produced via microwave-assisted co-precipitation method. The thermo/pH/magnetic field multi-sensitive hybrid nanoparticle was characterized by techniques like TEM, VSM, FT-IR, and TGA/DSC. In vitro release studies of 5-Fluorouracil (FL) were carried out by altering the temperature (37 and 44°C), pH (5.5 and 7.4) and presence of an AMF. The FL release of Pec-g-PolyDMAEMA@Fe₃O₄@FL exhibited pH-sensitive behavior. They showed thermo/pH-sensitive FL release features with the greatest release of FL at 37°C (56%) than at 44°C (40%) and at pH of 7.4 (63%) than at pH of 5.5 (45%) within 48h. The FL release was also significantly increased (100%) with the presence of a 50 mT magnetic field. These results indicate that the developed Pec-g-PolyDMAEMA@Fe₃O₄ nanoparticles are promising in the application of multi-stimuli-sensitive delivery of drugs.

Bridging the Gap of Drug Delivery in Colon Cancer: The Role of Chitosan and Pectin Based Nanocarriers System

Colon cancer is one of the most prevalent diseases, and traditional chemotherapy has not been proven beneficial in its treatment. It ranks second in terms of mortality due to all cancers for all ages. Lack of selectivity and poor biodistribution are the biggest challenges in developing potential therapeutic agents for the treatment of colon cancer. Nanoparticles hold enormous prospects as an effective drug delivery system. The delivery systems employing the use of polymers, such as chitosan and pectin as carrier molecules, ensure the maximum absorption of the drug, reduce unwanted side effects and also offer protection to the therapeutic agent from quick clearance or degradation, thus allowing an increased amount of the drug to reach the target tissue or cells. In this systematic review of published literature, the author aimed to assess the role of chitosan and pectin as polymer-carriers in colon targeted delivery of drugs in colon cancer therapy. This review summarizes the various studies employing the use of chitosan and pectin in colon targeted drug delivery systems.

Electrospun Orodispersible Films of Isoniazid for Pediatric Tuberculosis Treatment

Child-appropriate dosage forms are critical in promoting adherence and effective pharmacotherapy in pediatric patients, especially those undergoing long-term treatment in low-resource settings. The present study aimed to develop orodispersible films (ODFs) for isoniazid administration to children exposed to tuberculosis. The ODFs were produced from the aqueous solutions of natural and semi-synthetic polymer blends using electrospinning. The spinning solutions and the resulting fibers were physicochemically characterized, and the disintegration time and isoniazid release from the ODFs were assessed in simulated salivary fluid. The ODFs comprised of nanofibers with adequate thermal stability and possible drug amorphization. Film disintegration occurred instantly upon contact with simulated salivary fluid within less than 15 s, and isoniazid release from the ODFs in the same medium followed after the disintegration profiles, achieving rapid and total drug release within less than 60 s. The ease of administration and favorable drug loading and release properties of the ODFs may provide a dosage form able to facilitate proper adherence to treatment within the pediatric patient population.

Tuning the physicochemical properties of apple pectin films by incorporating chitosan/pectin fiber

Various biodegradable or edible films were designed to deal with the environmental threats from plastic films. To overcome the defects of pectin film, the feasibility for the incorporation of CH/PE fiber was explored. Micron-scale novel artificial CH/PE fibers in needle, spindle or whisker shape with a diameter around 25 μm were fabricated via a shearing regime in virtue of electrostatic complexing. The incorporation of CH/PE fiber (mixture) and its size-fractioned portions (small and large) substantially changed PE films in diverse ways. Structurally, the fiber-incorporated films were heterogeneous with the fibers concentrated in the upper layer, although they presented similar FT-IR spectra and XRD pattern to PE film. Regarding the film performance, the incorporation of CH/PE fibers, especially the small portion, rendered the PE film with higher values in water-proof ability, thermal stability, break resistibility, stretchability and UV blocking capacity. More importantly, this work provided an innovative strategy to improve the performance of edible films.

Development of solvent-free protocols for obtaining highly substituted maleates of hyaluronic acid and other glycosaminoglycans

Solvent-free protocols using microwave-assisted heating (i) or conventional heating without additives (ii) or adding K₂CO₃ (iii), or triturating at room temperature in the presence of K₂CO₃ (iv) were first used to esterify glycosaminoglycans (GAG) with maleic anhydride. High and low molecular weight hyaluronic acid (HMW and LMW HA), dermatan sulfate (Ds), heparin (HEP) and C6-oxidized HA (carboxy-HA) were used as substrates for maleation. Protocols (i)-(iii) were most effective for obtaining maleates with high DS (1.39-2.47), but had a strong degrading effect on GAG. Protocol (iv) did not have destructive effect, but was suitable for obtaining only HMW HA maleate (DS 0.71-1.15). Primary hydroxyl groups of HA and Ds showed a higher reactivity compared to the secondary ones. A specific feature of the HEP maleation was substitution of N-sulfate groups for N-maleate groups. To demonstrate the potential of the obtained maleates for thiol-ene click-chemical strategies, the reaction with l-cysteine was performed.

Catalyst-free esterification of high amylose starch with maleic anhydride in 1-butyl-3-methylimidazolium chloride: The effect of amylose content on the degree of MA substitution

The limited reactivity of starch towards maleic anhydride (MA) affords maleate with a low degree of MA substitutions (CC and COOH groups). In this study, we investigated the relationship between the starch structure, controlled by its amylose (AM)/amylopectin (AP) ratio, and the DS of starch maleates using C₄[mim]Cl as the recyclable media, and catalyst. The results indicated that starches with varying AM/AP ratio produced maleates with comparable CC groups (DS_NMR = 0.06-0.07). Following dissolution, the high amylose (DS_titration = 1.17, yield = 69.2 %) and regular starches (DS_titration = 1.17; yield = 59.3 %) produced high DS_titration maleates (COOH groups) at MA/AGU ratio of 12:1 (80 °C, 10 min). Comparatively, DS_titration value of waxy starch maleates (DS_titration = 0.88, yield = 59.3 %) was lower than AM-based starches, possibly due to the crosslinking tendency of AP branches consisting of carboxylic end-groups. Interestingly, DS_titration value for EHCS (1.17) ranged between its bulk (DS_NMR: 0.06) and surface distribution of MA (DSS_XPS 1.7); therefore, we considered it reliable for future reference.

Anisamide-functionalized pH-responsive amphiphilic chitosan-based paclitaxel micelles for sigma-1 receptor targeted prostate cancer treatment

Controlled release and tumor-selective distribution are highly desirable for anticancer nanomedicines. Here, we design and synthesize an anisamide-conjugated N-octyl-N,O-maleoyl-O-phosphoryl chitosan (a-OMPC) which can form amphiphilic micelles featuring pH-responsive release and high affinity to sigma-1 receptor-overexpressed tumors for paclitaxel (PTX) delivery. Thereinto, maleoyl and phosphoryl groups cooperatively contribute to pH-responsive drug release due to a conversion from hydrophile to hydrophobe in the acidic microenvironment of endo/lysosomes. We demonstrated that PTX-loaded a-OMPC micelles (PTX-aM) enhanced the cellular internalization via the affinity between anisamide and sigma-1 receptor, rapidly released drug in endo/lysosomes and elevated the cytotoxicity against PC-3 cells. The in vivo studies further verified that PTX-aM could largely accumulate at the tumor site even after 24 h of administration, resulting in obvious inhibition effect and prolonged survival period in PC-3 tumor xenograft-bearing mice. Moreover, OMPC showed no obvious hemolytic and acute toxicity. Collectively, this chitosan derivate holds a promising potential in application of prostate cancer-targeted drug delivery system.

Fabrication and Characterization of Pectin Hydrogel Nanofiber Scaffolds for Differentiation of Mesenchymal Stem Cells into Vascular Cells

Despite significant progress over the past few decades, creating a tissue-engineered vascular graft with replicated functions of native blood vessels remains a challenge due to the mismatch in mechanical properties, low biological function, and rapid occlusion caused by restenosis of small diameter vessel grafts (<6 mm diameter). A scaffold with similar mechanical properties and biocompatibility to the host tissue is ideally needed for the attachment and proliferation of cells to support the building of engineered tissue. In this study, pectin hydrogel nanofiber scaffolds with two different oxidation degrees (25 and 50%) were prepared by a multistep methodology including periodate oxidation, electrospinning, and adipic acid dihydrazide crosslinking. Scanning electron microscopy (SEM) images showed that the obtained pectin nanofiber mats have a nano-sized fibrous structure with 300-400 nm fiber diameter. Physicochemical property testing using Fourier transform infrared (FTIR) spectra, atomic force microscopy (AFM) nanoindentations, and contact angle measurements demonstrated that the stiffness and hydrophobicity of the fiber mat could be manipulated by adjusting the oxidation and crosslinking levels of the pectin hydrogels. Live/Dead staining showed high viability of the mesenchymal stem cells (MSCs) cultured on the pectin hydrogel fiber scaffold for 14 days. In addition, the potential application of pectin hydrogel nanofiber scaffolds of different stiffness in stem cell differentiation into vascular cells was assessed by gene expression analysis. Real-time polymerase chain reaction (RT-PCR) results showed that the stiffer scaffold facilitated the differentiation of MSCs into vascular smooth muscle cells, while the softer fiber mat promoted MSC differentiation into endothelial cells. Altogether, our results indicate that the pectin hydrogel nanofibers have the capability of providing mechanical cues that induce MSC differentiation into vascular cells and can be potentially applied in stem cell-based tissue engineering.

Butylglyceryl Pectin Nanoparticles: Synthesis, Formulation and Characterization

Pectin is a polysaccharide with very good gel forming properties that traditionally has found important applications in foods and pharmaceutical industries. Although less studied, chemical modifications of pectin leading to a decrease in its hydrophilicity can be useful for the development of novel drug carriers. To this aim, butylglyceryl pectins (P-OX4) were synthesized via functionalization with n-butylglycidyl ether and subsequently formed into nanoparticles. Chromatographic, spectroscopic, and thermal analytical methods were employed to characterize the novel butylglyceryl pectins (P-OX4) obtained, prior to their formulation into nanoparticles via nanoprecipitation. Nuclear magnetic resonance (NMR) and Fourier transform infrared (FT-IR) spectroscopy confirmed a degree of modification in these materials in the range 10.4-13.6%, and thermal stability studies indicated an increase in both the thermal decomposition onset and glass transition temperature values (compared to those of the original pectin). An increase in the molecular weight and a decrease in the viscosity of P-OX4, when compared to the starting material, were also observed. The resulting nanoformulations were investigated in terms of particle morphology, size and stability, and it was found that particles were roughly spherical, with their size below 300 nm, and a negative zeta potential (-20 to -26 mV, indicating good stability). Having demonstrated the ability to load Doxorubicin at the level of 10%, their potential in drug delivery applications warrants further investigations.

Fabrication and characterization of pectin-based three-dimensional porous scaffolds suitable for treatment of peritoneal adhesions

Formation of peritoneal adhesions is common complication after abdominal and pelvic surgery. They bear a significant health problem with an influence to quality of life and health care expenses. Promising approach for their prevention is using of biodegradable barrier films for physical separation of peritoneal surfaces. In the present study, highly porous pectin-based three-dimensional (3D) scaffolds were obtained by freeze-drying technique. Physico-chemical properties of the formed materials, including their morphology, porosity, density, and stability, have been studied. The evaluation of their biocompatibility, biodegradation, and potential antiadhesion effect was studied by in vivo experiment. To reinforce the scaffolds structure and improve their stability in physiological solutions, pectin chains were cross-linked with divalent cations. We determined optimal cross-linking conditions, which allow obtaining scaffolds with desired biodegradation rate. These cross-linked scaffolds fully dissolved within 8 days in the peritoneal cavity with low presence of complications and some antiadhesive effect. It has also been determined that mesenchymal stem cells from adipose tissue could effectively adhere to the scaffolds with preservation of their viability. Our results show that obtained materials can be suggested as mechanical scaffold for delivery of the stem cells culture to peritoneal surfaces as a part of complex antiadhesive barrier system.

Structure and Anti-Tumor Activities of Exopolysaccharides from Alternaria mali Roberts

In this study, an extracellular polysaccharide from Alternaria mali Roberts (AMEP) was extracted, and its structure was characterized, in addition to its antitumor activity in vitro. Neutral polysaccharide AMEP-1 and anionic polysaccharide AMEP-2 were isolated from AMEP, and their monosaccharide compositions consisted of mannose (Man), glucose (Glc), and galactose (Gal) but at different ratios. The linking mode of both AMEP-1 and AMEP-2 is Manp-(1→4) and Glcp-(1→6), and the branched chains are connected to the main chain through O-6. AMEP-2 inhibited the proliferation of BGC-823 cells in a time- and concentration-dependent manner. AMEP-2 also induced the apoptosis of BGC-823 cells, and showed anti-tumor effects by inducing cell cycle arrest in the S phase, reactive oxygen species production, and mitochondrial membrane potential reduction in BGC-823 cells. Therefore, AMEP-2 shows potential for further development as a novel anti-tumor agent.

Preparation of methyl alginate and its application in acidified milk drinks

A series of methyl alginate with different degree of esterification (DE) were prepared with low cost, and its application in acidified milk drinks (AMDs) was investigated. The gel strength, molecular weight, solution apparent viscosity and optical rotation value of methyl alginate all decreased with the increase of DE. Methyl alginate with DE equal or larger than 60.7% was more effective in stabilizing AMDs than high-methoxyl pectin (HMP) under the same conditions, and the higher the DE, the better its stabilizing ability. The methyl alginate had better synergistic action for stabilizing AMDs with propylene glycol alginate (PGA) than HMP. The reason for this could be attributed to that methyl alginate and PGA had the same main chain structure, and the same levorotatory optical activity. The results indicated that the methyl alginate had a potential industry application prospect for stabilizing AMDs as an alternative to HMP.

The Effect of Glycerol, Sugar, and Maleic Anhydride on Pectin-Cellulose Thin Films Prepared from Orange Waste

This study was conducted to improve the properties of thin films prepared from orange waste by the solution casting method. The main focus was the elimination of holes in the film structure by establishing better cohesion between the major cellulosic and pectin fractions. For this, a previously developed method was improved first by the addition of sugar to promote pectin gelling, then by the addition of maleic anhydride. Principally, maleic anhydride was introduced to the films to induce cross-linking within the film structure. The effects of concentrations of sugar and glycerol as plasticizers and maleic anhydride as a cross-linking agent on the film characteristics were studied. Maleic anhydride improved the structure, resulting in a uniform film, and morphology studies showed better adhesion between components. However, it did not act as a cross-linking agent, but rather as a compatibilizer. The middle level (0.78%) of maleic anhydride content resulted in the highest tensile strength (26.65 ± 3.20 MPa) at low (7%) glycerol and high (14%) sugar levels and the highest elongation (28.48% ± 4.34%) at high sugar and glycerol levels. To achieve a uniform film surface with no holes present, only the lowest (0.39%) level of maleic anhydride was necessary.

Pectin Oligosaccharides Ameliorate Colon Cancer by Regulating Oxidative Stress- and Inflammation-Activated Signaling Pathways

Colon cancer (CC) is the third common neoplasm worldwide, and it is still a big challenge for exploring new effective medicine for treating CC. Natural product promoting human health has become a hot topic and attracted many researchers recently. Pectin, a complex polysaccharide in plant cell wall, mainly consists of four major types of polysaccharides: homogalacturonan, xylogalacturonan, rhamnogalacturonan I and II, all of which can be degraded into various pectin oligosaccharides (POS) and may provide abundant resource for exploring potential anticancer drugs. POS have been regarded as a novel class of potential functional food with multiple health-promoting properties. POS have antibacterial activities against some aggressive and recurrent bacterial infection and exert beneficial immunomodulation for controlling CC risk. However, the molecular functional role of POS in the prevention of CC risk and progression remains doubtful. The review focuses on antioxidant and anti-inflammatory roles of POS for promoting human health by regulating some potential oxidative and inflammation-activated pathways, such as ATP-activated protein kinase (AMPK), nuclear factor erythroid-2-related factor-2 (Nrf2), and nuclear factor-κB (NF-κB) pathways. The activation of these signaling pathways increases the antioxidant and antiinflammatory activities, which will result in the apoptosis of CC cells or in the prevention of CC risk and progression. Thus, POS may inhibit CC development by affecting antioxidant and antiinflammatory signaling pathways AMPK, Nrf2, and NF-κB. However, POS also can activate signal transduction and transcriptional activator 1 and 3 signaling pathway, which will reduce antioxidant and anti-inflammatory properties and promote CC progression. Specific structural and structurally modified POS may be associated with their functions and should be deeply explored in the future. The present review paper lacks the important information for the linkage between the specific structure of POS and its function. To further explore the effects of prebiotic potential of POS and their derivatives on human immunomodulation in the prevention of CC, the specific POS with a certain degree of polymerization or purified polymers are highly demanded to be performed in clinical practice.

Antitumor activity of chitosan from mayfly with comparison to commercially available low, medium and high molecular weight chitosans

Insects' cuticles have a potential to be evaluated as a chitin source. Especially adults of aquatic insects like mayflies (order Ephemeroptera) swarm in enormous numbers in artificially lit areas while mating in spring and then die by leaving huge amounts of dead insects' bodies. Here in this study, mayfly corpses were harvested and used for production of low MW chitosan. Dried mayfly bodies had 10.21% chitin content; mayfly chitin was converted into chitosan with efficiency rate of 78.43% (deacetylation degree, 84.3%; MW, 3.69 kDa). Cytotoxicity and anti-proliferative activity of mayfly and commercially available shrimp chitosans (low, medium, and high MW) were determined on L929 fibroblast and three different cancer types including HeLa, A549, and WiDr. Apoptosis and necrosis stimulating potential of mayfly and commercial chitosans were also evaluated on A549 and WiDr cells using acridine orange and propidium iodide dual staining to observe morphological changes in nuclei and thus to reveal the predominant cell death mechanism. The effects of chitosans have varied depending on cell types, concentration, and chitosan derivatives. Mayfly and low MW chitosans had a cytotoxic effect at a concentration of 500 μg mL^-1 on non-cancer cells. At concentrations below this value (250 μg mL^-1), mayfly and commercial chitosans except high MW one exhibited strong inhibitory activity on cancer cells especially A549 and WiDr cells. Mayfly chitosan induced early and late apoptosis in A549 cells, but late apoptosis and necrosis in WiDr cells. This study suggests that dead bodies of mayflies can be used for production of low MW chitosan with anti-proliferative activity.