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Special Issue "Polymeric Systems Loaded with Natural Bioactive Compounds"

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A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Materials Chemistry".

Deadline for manuscript submissions: closed (30 September 2023) | Viewed by 19512

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Prof. Dr. Marcel Popa

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“Cristofor Simionescu” Faculty of Chemical Engineering and Environment Protection, “Gheorghe Asachi” Technical University, 700050 Iasi, Romania
Interests: polysaccharide modification; bioactive polymers; biomaterials; hydrogels; interpenetrated networks; micro- and nanoparticles (spheres and capsules); hybrid and functionalized nanoparticles for drug targeting; drug delivery; polymer–drug conjugates
Special Issues, Collections and Topics in MDPI journals

Prof. Dr. Leonard-Ionut Atanase

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1. Faculty of Dental Medicine, “Apollonia” University, Iasi, Romania
2. Academy of Romanian Scientists, Ilfov Street, Bucharest, Romania
Interests: block and graft copolymers; micelles; colloids; emulsions; drug delivery; polysaccharides
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

From ancient times people have used natural products derived from plants and sometimes animals as medicines against various diseases because they show great structural diversity that influences biological properties and bioavailability. Natural products such as polyphenols, omega-3 fatty acids, phytosterols, carotenoids, vitamins, alkaloids etc. can modulate metabolic processes and demonstrate positive properties such as antioxidant effect, inhibition of receptor activities, inhibition or induction of enzymes, and the induction and inhibition of gene expression. However, most bioactive natural compounds have low water solubility, stability and bioavailability. Nanotechnology plays an important role in improving these properties, improving their absorption, protecting them from premature degradation in the body and prolonging their circulation time. Many nanostructured systems have been developed for the loading, transport and controlled release of the active compound into the body, or even at the specific target of these natural products. These include hydrogels/nanohydrogels, liposomes, polymeric nanoparticles (nanospheres and nanocapsules), solid lipid nanoparticles, nanoemulsions, polymeric micelles etc.

This Special Issue aims to present the latest aspects regarding the preparation and characterization of natural biologically active principles loaded in polymer-based films, hydrogels, micro/nanoparticles, micelles, capsules, implants, inserts, liposomes stabilized by polymer coatings etc.

Prof. Dr. Marcel Popa
Prof. Dr. Leonard Atanase
Guest Editors

Manuscript Submission Information

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Keywords

polymer–natural drug systems
polyphenols
polymer–drug conjugates
biomaterials
drug delivery
natural bioactive compounds
active targeting
omega 3 fatty acids
carotenoids
vitamins

Published Papers (9 papers)

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Research

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Open AccessArticle

An Accessible Method to Improve the Stability and Reusability of Porcine Pancreatic α-Amylase via Immobilization in Gellan-Based Hydrogel Particles Obtained by Ionic Cross-Linking with Mg²⁺ Ions

Camelia Elena Tincu (Iurciuc)

Brahim Bouhadiba

Leonard Ionut Atanase

Corneliu Sergiu Stan

Marcel Popa

and

Lăcrămioara Ochiuz

Molecules 2023, 28(12), 4695; https://doi.org/10.3390/molecules28124695 - 11 Jun 2023

Cited by 1 | Viewed by 807

Abstract

Amylase is an enzyme used to hydrolyze starch in order to obtain different products that are mainly used in the food industry. The results reported in this article refer to the immobilization of α-amylase in gellan hydrogel particles ionically cross-linked with Mg²⁺ ions. The obtained hydrogel particles were characterized physicochemically and morphologically. Their enzymatic activity was tested using starch as a substrate in several hydrolytic cycles. The results showed that the properties of the particles are influenced by the degree of cross-linking and the amount of immobilized α-amylase enzyme. The temperature and pH at which the immobilized enzyme activity is maximum were T = 60 °C and pH = 5.6. The enzymatic activity and affinity of the enzyme to the substrate depend on the particle type, and this decreases for particles with a higher cross-linking degree owing to the slow diffusion of the enzyme molecules inside the polymer’s network. By immobilization, α-amylase is protected from environmental factors, and the obtained particles can be quickly recovered from the hydrolysis medium, thus being able to be reused in repeated hydrolytic cycles (at least 11 cycles) without a substantial decrease in enzymatic activity. Moreover, α-amylase immobilized in gellan particles can be reactivated via treatment with a more acidic medium. Full article

(This article belongs to the Special Issue Polymeric Systems Loaded with Natural Bioactive Compounds)

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Open AccessArticle

Silymarin Encapsulated Liposomal Formulation: An Effective Treatment Modality against Copper Toxicity Associated Liver Dysfunction and Neurobehavioral Abnormalities in Wistar Rats

and

Molecules 2023, 28(3), 1514; https://doi.org/10.3390/molecules28031514 - 03 Feb 2023

Cited by 1 | Viewed by 1469

Abstract

Wilson’s disease causes copper accumulation in the liver and extrahepatic organs. The available therapies aim to lower copper levels by various means. However, a potent drug that can repair the damaged liver and brain tissue is needed. Silymarin has hepatoprotective, antioxidant, and cytoprotective properties. However, poor oral bioavailability reduces its efficacy. In this study, a “thin film hydration method” was used for synthesizing silymarin-encapsulated liposome nanoparticles (SLNPs) and evaluated them against copper toxicity, associated liver dysfunction and neurobehavioral abnormalities in Wistar rats. After copper toxicity induction, serological and behavioral assays were conducted to evaluate treatment approaches. Histological examination of the diseased rats revealed severe hepatocyte necrosis and neuronal vacuolation. These cellular degenerations were mild in rats treated with SLNPs and a combination of zinc and SLNPs (ZSLNPs). SLNPs also decreased liver enzymes and enhanced rats’ spatial memory significantly (p = 0.006) in the diseased rats. During forced swim tests, SLNPs treated rats exhibited a 60-s reduction in the immobility period, indicating reduced depression. ZSLNPs were significantly more effective than traditional zinc therapy in decreasing the immobility period (p = 0.0008) and reducing liver enzymes, but not in improving spatial memory. Overall, SLNPs enhanced oral silymarin administration and managed copper toxicity symptoms. Full article

(This article belongs to the Special Issue Polymeric Systems Loaded with Natural Bioactive Compounds)

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Open AccessArticle

Development of Gastroretentive Carriers for Curcumin-Loaded Solid Dispersion Based on Expandable Starch/Chitosan Films

Worrawee Siripruekpong

Ousanee Issarachot

Kanidta Kaewkroek

and

Ruedeekorn Wiwattanapatapee

Molecules 2023, 28(1), 361; https://doi.org/10.3390/molecules28010361 - 01 Jan 2023

Viewed by 1604

Abstract

Curcumin, a polyphenolic extract from the rhizomes of turmeric, exhibits antioxidant, anti-inflammatory, and anticancer activities, which are beneficial for the treatment of gastric diseases. However, curcumin’s therapeutic usefulness is restricted by its low aqueous solubility and short gastric residence time. In this study, curcumin-loaded solid dispersion (ratio 1:5) was prepared using Eudragit^® EPO (Cur EPO-SD), resulting in an approximately 12,000-fold increase in solubility to 6.38 mg/mL. Expandable films incorporating Cur EPO-SD were subsequently prepared by solvent casting using different types of starch (banana, corn, pregelatinized, and mung bean starch) in combination with chitosan. Films produced from banana, corn, pregelatinized and mung bean starch unfolded and expanded upon exposure to simulated gastric medium, resulting in sustained release of 80% of the curcumin content within 8 h, whereas films based on pregelatinized starch showed immediate release characteristics. Curcumin-loaded expandable films based on different types of starch exhibited similar cytotoxic effects toward AGS cells and more activity than unformulated curcumin. Furthermore, the films resulted in increased anti-inflammatory activity against RAW 264.7 macrophage cells compared with the NSAID, indomethacin. These findings demonstrate the potential of expandable curcumin-loaded films as gastroretentive dosage forms for the treatment of gastric diseases and to improve oral bioavailability. Full article

(This article belongs to the Special Issue Polymeric Systems Loaded with Natural Bioactive Compounds)

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Open AccessArticle

Effect of Loblolly Pine (Pinus taeda L.) Hemicellulose Structure on the Properties of Hemicellulose-Polyvinyl Alcohol Composite Film

and

Molecules 2023, 28(1), 46; https://doi.org/10.3390/molecules28010046 - 21 Dec 2022

Cited by 1 | Viewed by 905

Abstract

Hemicellulose is the second most abundant natural polysaccharide and a promising feedstock for biomaterial synthesis. In the present study, the hemicellulose of loblolly pine was obtained by the alkali extraction-graded ethanol precipitation technique, and the hemicellulose-polyvinyl alcohol (hemicellulose-PVA) composite film was prepared by film casting from water. Results showed that hemicellulose with a low degree of substitution is prone to self-aggregation during film formation, while hemicellulose with high branching has better compatibility with PVA and is easier to form a homogeneous composite film. In addition, the higher molecular weight of hemicellulose facilitates the preparation of hemicellulose-PVA composite film with better mechanical properties. More residual lignin in hemicellulose results in the better UV shielding ability of the composite film. This study provides essential support for the efficient and rational utilization of hemicellulose. Full article

(This article belongs to the Special Issue Polymeric Systems Loaded with Natural Bioactive Compounds)

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Open AccessArticle

pH-Responsive Hydrogel Beads Based on Alginate, κ-Carrageenan and Poloxamer for Enhanced Curcumin, Natural Bioactive Compound, Encapsulation and Controlled Release Efficiency

Katarina S. Postolović

Milan D. Antonijević

Biljana Ljujić

Marina Miletić Kovačević

Marina Gazdić Janković

and

Zorka D. Stanić

Molecules 2022, 27(13), 4045; https://doi.org/10.3390/molecules27134045 - 23 Jun 2022

Cited by 11 | Viewed by 1943

Abstract

Polyphenolic compounds are used for treating various diseases due to their antioxidant and anticancer properties. However, utilization of hydrophobic compounds is limited due to their low bioavailability. In order to achieve a greater application of hydrophobic bioactive compounds, hydrogel beads based on biopolymers can be used as carriers for their enhanced incorporation and controlled delivery. In this study, beads based on the biopolymers-κ-carrageenan, sodium alginate and poloxamer 407 were prepared for encapsulation of curcumin. The prepared beads were characterized using IR, SEM, TGA and DSC. The curcumin encapsulation efficiency in the developed beads was 95.74 ± 2.24%. The release kinetics of the curcumin was monitored in systems that simulate the oral delivery (pH 1.2 and 7.4) of curcumin. The drug release profiles of the prepared beads with curcumin indicated that the curcumin release was significantly increased compared with the dissolution of curcumin itself. The cumulative release of curcumin from the beads was achieved within 24 h, with a final release rate of 12.07% (gastric fluid) as well as 81.93% (intestinal fluid). Both the in vitro and in vivo studies showed that new hydrogel beads based on carbohydrates and poloxamer improved curcumin’s bioavailability, and they can be used as powerful carriers for the oral delivery of different hydrophobic nutraceuticals. Full article

(This article belongs to the Special Issue Polymeric Systems Loaded with Natural Bioactive Compounds)

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Open AccessArticle

Evaluation of Electrospun PCL-PLGA for Sustained Delivery of Kartogenin

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Molecules 2022, 27(12), 3739; https://doi.org/10.3390/molecules27123739 - 10 Jun 2022

Cited by 3 | Viewed by 1770

Abstract

In this study, kartogenin was incorporated into an electrospun blend of polycaprolactone and poly(lactic-co-glycolic acid) (1:1) to determine the feasibility of this system for sustained drug delivery. Kartogenin is a small-molecule drug that could enhance the outcome of microfracture, a cartilage restoration procedure, by selectively stimulating chondrogenic differentiation of endogenous bone marrow mesenchymal stem cells. Experimental results showed that kartogenin did not affect the electrospinnability of the polymer blend, and it had negligible effects on fiber morphology and scaffold mechanical properties. The loading efficiency of kartogenin into electrospun membranes was nearly 100%, and no evidence of chemical reaction between kartogenin and the polymers was detected by Fourier transform infrared spectroscopy. Analysis of the released drug using high-performance liquid chromatography–photodiode array detection indicated an abundance of kartogenin and only a small amount of its major hydrolysis product. Kartogenin displayed a typical biphasic release profile, with approximately 30% being released within 24 h followed by a much slower, constant rate of release up to 28 days. Although additional development is needed to tune the release kinetics and address issues common to electrospun scaffolds (e.g., high fiber density), the results of this study demonstrated that a scaffold electrospun from biodegradable synthetic polymers is a suitable kartogenin delivery vehicle. Full article

(This article belongs to the Special Issue Polymeric Systems Loaded with Natural Bioactive Compounds)

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Open AccessArticle

Curcumin–Induced Stabilization of Protein–Based Nano-Delivery Vehicles Reduces Disruption of Zwitterionic Giant Unilamellar Vesicles

Ogadimma D. Okagu

Raliat O. Abioye

and

Chibuike C. Udenigwe

Molecules 2022, 27(6), 1941; https://doi.org/10.3390/molecules27061941 - 17 Mar 2022

Cited by 1 | Viewed by 1872

Abstract

Curcumin-loaded native and succinylated pea protein nanoparticles, as well as zwitterionic giant unilamellar vesicles were used in this study as model bioactive compound loaded-nanoparticles and biomembranes, respectively, to assess bio-nano interactions. Curcumin-loaded native protein-chitosan and succinylated protein-chitosan complexes, as well as native protein-chitosan and succinylated protein-chitosan hollow, induced leakage of the calcein encapsulated in the giant unilamellar vesicles. The leakage was more pronounced with hollow protein-chitosan complexes. However, curcumin-loaded native protein and curcumin-loaded succinylated protein nanoparticles induced calcein fluorescence quenching. Dynamic light scattering measurements showed that the interaction of curcumin-loaded native protein, curcumin-loaded succinylated protein, native protein-chitosan, and succinylated protein-chitosan complexes with the giant unilamellar vesicles caused a major reduction in the size of the lipid vesicles. Confocal and widefield fluorescence microscopy showed rupturing of the unilamellar vesicles after treatment with native pea protein-chitosan and succinylated pea protein-chitosan complexes. The nature of interaction between the curcumin-loaded protein nanoparticles and the biomembranes, at the bio-nano interface, is influenced by the encapsulated curcumin. Findings from this study showed that, as the protein plays a crucial role in stabilizing the bioactive compound from chemical and photodegradation, the encapsulated nutraceutical stabilizes the protein nanoparticle to reduce its interaction with biomembranes. Full article

(This article belongs to the Special Issue Polymeric Systems Loaded with Natural Bioactive Compounds)

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Open AccessArticle

Enhanced Sunscreen Effects via Layer-By-Layer Self-Assembly of Chitosan/Sodium Alginate/Calcium Chloride/EHA

and

Molecules 2022, 27(3), 1148; https://doi.org/10.3390/molecules27031148 - 08 Feb 2022

Cited by 2 | Viewed by 2357

Abstract

The sunscreen nanocapsules were successfully synthesized by the way of layer-by-layer self-assembly using charged droplets (prepared by emulsification of LAD-30, Tween-80 and EHA (2-Ethylhexyl-4-dimethylaminobenzoate)) as templates. Chitosan/sodium alginate/calcium chloride were selected as wall materials to wrap EHA. The emulsions with the ratio of Tween-80 to EHA (1:1) were stable. A stable NEI negative emulsion can be obtained when the ratio of Tween-80 and LAD-30 was 9:1. Chitosan solutions (50 kDa, 0.25 mg/mL) and sodium alginate solutions (0.5 mg/mL) were selected to prepare nanocapsules. The nanocapsules were characterized via some physico-chemical methods. Based on the synergistic effects of the electrostatic interaction between wall materials and emulsifiers, EHA was effectively encapsulated. DLS and TEM showed that the sunscreen nanocapsules were dispersed in a spherical shape with nano-size, with the increasing number of assembly layers, the size increased from 155 nm (NEI) to 189 nm (NEII) to 201 nm (NEIII) and 205 nm after solidification. The release studies in vitro showed sustained release behavior of the nanocapsules were observed with the increase of the number of deposition layers, implying a good coating effect. The sunscreen nanocapsules could control less than 50% the release of EHA after crosslinking of calcium chloride and sodium alginate, which also could effectively avoid the stimulation of the sun protection agent on the skin. Full article

(This article belongs to the Special Issue Polymeric Systems Loaded with Natural Bioactive Compounds)

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Open AccessReview

Modification of Alginates to Modulate Their Physic-Chemical Properties and Obtain Biomaterials with Different Functional Properties

and

Molecules 2021, 26(23), 7264; https://doi.org/10.3390/molecules26237264 - 30 Nov 2021

Cited by 23 | Viewed by 5080

Abstract

Modified alginates have a wide range of applications, including in the manufacture of dressings and scaffolds used for regenerative medicine, in systems for selective drug delivery, and as hydrogel materials. This literature review discusses the methods used to modify alginates and obtain materials with new or improved functional properties. It discusses the diverse biological and functional activity of alginates. It presents methods of modification that utilize both natural and synthetic peptides, and describes their influence on the biological properties of the alginates. The success of functionalization depends on the reaction conditions being sufficient to guarantee the desired transformations and provide modified alginates with new desirable properties, but mild enough to prevent degradation of the alginates. This review is a literature description of efficient methods of alginate functionalization using biologically active ligands. Particular attention was paid to methods of alginate functionalization with peptides, because the combination of the properties of alginates and peptides leads to the obtaining of conjugates with properties resulting from both components as well as a completely new, different functionality. Full article

(This article belongs to the Special Issue Polymeric Systems Loaded with Natural Bioactive Compounds)

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