Polymers

Editorial

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5 pages, 1250 KiB

Open AccessEditorial

Polymeric Carriers for Delivery Systems in Biomedical Applications—In Memory of Professor Andrzej Dworak

by Alicja Utrata-Wesołek, Barbara Trzebicka, Jerzy Polaczek, Iza Radecka and Marek Kowalczuk

Polymers 2023, 15(8), 1810; https://doi.org/10.3390/polym15081810 - 7 Apr 2023

Cited by 1 | Viewed by 3831

Abstract

Since the appearance of the first civilizations, various substances have been used to improve human health [...] Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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Research

Jump to: Editorial, Review

16 pages, 3205 KiB

Open AccessArticle

Highly Sensitive Detection of Bacteria by Binder-Coupled Multifunctional Polymeric Dyes

by Kriti Kapil, Shirley Xu, Inseon Lee, Hironobu Murata, Seok-Joon Kwon, Jonathan S. Dordick and Krzysztof Matyjaszewski

Polymers 2023, 15(12), 2723; https://doi.org/10.3390/polym15122723 - 18 Jun 2023

Cited by 6 | Viewed by 2056

Abstract

Infectious diseases caused by pathogens are a health burden, but traditional pathogen identification methods are complex and time-consuming. In this work, we have developed well-defined, multifunctional copolymers with rhodamine B dye synthesized by atom transfer radical polymerization (ATRP) using fully oxygen-tolerant photoredox/copper dual [...] Read more.

Infectious diseases caused by pathogens are a health burden, but traditional pathogen identification methods are complex and time-consuming. In this work, we have developed well-defined, multifunctional copolymers with rhodamine B dye synthesized by atom transfer radical polymerization (ATRP) using fully oxygen-tolerant photoredox/copper dual catalysis. ATRP enabled the efficient synthesis of copolymers with multiple fluorescent dyes from a biotin-functionalized initiator. Biotinylated dye copolymers were conjugated to antibody (Ab) or cell-wall binding domain (CBD), resulting in a highly fluorescent polymeric dye-binder complex. We showed that the unique combination of multifunctional polymeric dyes and strain-specific Ab or CBD exhibited both enhanced fluorescence and target selectivity for bioimaging of Staphylococcus aureus by flow cytometry and confocal microscopy. The ATRP-derived polymeric dyes have the potential as biosensors for the detection of target DNA, protein, or bacteria, as well as bioimaging. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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19 pages, 3975 KiB

Open AccessArticle

Antioxidant and Antiradical Activities of Hibiscus sabdariffa L. Extracts Encapsulated in Calcium Alginate Spheres

by Pascal Bevan, Maria Vicenta Pastor, María Pilar Almajano and Idoia Codina-Torrella

Polymers 2023, 15(7), 1740; https://doi.org/10.3390/polym15071740 - 31 Mar 2023

Cited by 6 | Viewed by 2052

Abstract

The interest in natural sources with high antioxidant powder has recently increased in several sectors. Ionic gelation methods could be used to protect bioactive substances to control the kinetics and release of these ingredients to the food matrix. This study dealt with the [...] Read more.

The interest in natural sources with high antioxidant powder has recently increased in several sectors. Ionic gelation methods could be used to protect bioactive substances to control the kinetics and release of these ingredients to the food matrix. This study dealt with the evaluation of the antioxidant capacity and scavenging activity of extracts of Hibiscus Sabdariffa L. (HSL) (with 50% ethanol) encapsulated in calcium alginate spheres as a new source for preserving food against oxidative damage. Their antioxidant activity was measured in different o/w emulsions in which HSL spheres reduced the formation of hydroperoxides (~80%) and thiobarbituric-acid-reactive substance products (~20%). The scavenging activity of HSL extracts was measured in different food simulants (water, water acidified with 3% acetic acid, ethanol at 50%, and pure ethanol), and corresponded to 0.20–0.43, 0.31–0.62, and 11.13–23.82 mmol Trolox/mL extract for Trolox equivalent antioxidant capacity (TEAC), 2,2-diphenylpicrylhydrazyl (DPPH), and oxygen radical absorbance capacity (ORAC) assays, respectively. In general, the best antiradical activity was observed in the ethanolic and acidified mediums, in which the highest concentration of released polyphenols ranged from 0.068 to 0.079 mg GAE/mL. This work indicates the potential of alginate spheres for encapsulating antioxidant compounds as an innovative strategy for several industrial applications. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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24 pages, 4011 KiB

Open AccessArticle

Amphiphilic Copolymer-Lipid Chimeric Nanosystems as DNA Vectors

by Varvara Chrysostomou, Aleksander Foryś, Barbara Trzebicka, Costas Demetzos and Stergios Pispas

Polymers 2022, 14(22), 4901; https://doi.org/10.3390/polym14224901 - 13 Nov 2022

Cited by 3 | Viewed by 2728

Abstract

Lipid-polymer chimeric (hybrid) nanosystems are promising platforms for the design of effective gene delivery vectors. In this regard, we developed DNA nanocarriers comprised of a novel poly[(stearyl methacrylate-co-oligo(ethylene glycol) methyl ether methacrylate] [P(SMA-co-OEGMA)] amphiphilic random copolymer, the cationic 1,2-dioleoyl-3-(trimethylammonium) propane (DOTAP), and the [...] Read more.

Lipid-polymer chimeric (hybrid) nanosystems are promising platforms for the design of effective gene delivery vectors. In this regard, we developed DNA nanocarriers comprised of a novel poly[(stearyl methacrylate-co-oligo(ethylene glycol) methyl ether methacrylate] [P(SMA-co-OEGMA)] amphiphilic random copolymer, the cationic 1,2-dioleoyl-3-(trimethylammonium) propane (DOTAP), and the zwitterionic L-α-phosphatidylcholine, hydrogenated soybean (soy) (HSPC) lipids. Chimeric HSPC:DOTAP:P[(SMA-co-OEGMA)] nanosystems, and pure lipid nanosystems as reference, were prepared in several molar ratios of the components. The colloidal dispersions obtained presented well-defined physicochemical characteristics and were further utilized for the formation of lipoplexes with a model DNA of linear topology containing 113 base pairs. Nanosized complexes were formed through the electrostatic interaction of the cationic lipid and phosphate groups of DNA, as observed by dynamic, static, and electrophoretic light scattering techniques. Ultraviolet–visible (UV–Vis) and fluorescence spectroscopy disclosed the strong binding affinity of the chimeric and also the pure lipid nanosystems to DNA. Colloidally stable chimeric/lipid complexes were formed, whose physicochemical characteristics depend on the N/P ratio and on the molar ratio of the building components. Cryogenic transmission electron microscopy (Cryo-TEM) revealed the formation of nanosystems with vesicular morphology. The results suggest the successful fabrication of these novel chimeric nanosystems with well-defined physicochemical characteristics, which can form stable lipoplexes. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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13 pages, 3174 KiB

Open AccessArticle

Functional Nanogel from Natural Substances for Delivery of Doxorubicin

by Katya Kamenova, Lyubomira Radeva, Krassimira Yoncheva, Filip Ublekov, Martin A. Ravutsov, Maya K. Marinova, Svilen P. Simeonov, Aleksander Forys, Barbara Trzebicka and Petar D. Petrov

Polymers 2022, 14(17), 3694; https://doi.org/10.3390/polym14173694 - 5 Sep 2022

Cited by 8 | Viewed by 2697

Abstract

Nanogels (NGs) have attracted great attention because of their outstanding biocompatibility, biodegradability, very low toxicity, flexibility, and softness. NGs are characterized with a low and nonspecific interaction with blood proteins, meaning that they do not induce any immunological responses in the body. Due [...] Read more.

Nanogels (NGs) have attracted great attention because of their outstanding biocompatibility, biodegradability, very low toxicity, flexibility, and softness. NGs are characterized with a low and nonspecific interaction with blood proteins, meaning that they do not induce any immunological responses in the body. Due to these properties, NGs are considered promising candidates for pharmaceutical and biomedical application. In this work, we introduce the development of novel functional nanogel obtained from two naturally based products—citric acid (CA) and pentane-1,2,5-triol (PT). The nanogel was synthesized by precipitation esterification reaction of CA and PT in tetrahydrofuran using N-ethyl-N′-(3-dimethylaminopropyl) carbodiimide (EDC) and 4-(dimethylamino)pyridine (DMAP) catalyst system. Dynamic light scattering (DLS), cryogenic transmission electron microscopy (cryo-TEM) and atomic force microscopy (AFM) analyses revealed formation of spherical nanogel particles with a negative surface charge. Next, the nanogel was loaded with doxorubicin hydrochloride (DOX) by electrostatic interactions between carboxylic groups present in the nanogel and amino groups of DOX. The drug-loaded nanogel exhibited high encapsulation efficiency (EE~95%), and a bi-phasic release behavior. Embedding DOX into nanogel also stabilized the drug against photodegradation. The degradability of nanogel under acidic and neutral conditions with time was investigated as well. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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18 pages, 2139 KiB

Open AccessArticle

Microbial Poly-γ-Glutamic Acid (γ-PGA) as an Effective Tooth Enamel Protectant

by Mattia Parati, Louisa Clarke, Paul Anderson, Robert Hill, Ibrahim Khalil, Fideline Tchuenbou-Magaia, Michele S. Stanley, Donal McGee, Barbara Mendrek, Marek Kowalczuk and Iza Radecka

Polymers 2022, 14(14), 2937; https://doi.org/10.3390/polym14142937 - 20 Jul 2022

Cited by 9 | Viewed by 2593

Abstract

Poly-γ-glutamic acid (γ-PGA) is a bio-derived water-soluble, edible, non-immunogenic nylon-like polymer with the biochemical characteristics of a polypeptide. This Bacillus-derived material has great potential for a wide range of applications, from bioremediation to tunable drug delivery systems. In the context of oral [...] Read more.

Poly-γ-glutamic acid (γ-PGA) is a bio-derived water-soluble, edible, non-immunogenic nylon-like polymer with the biochemical characteristics of a polypeptide. This Bacillus-derived material has great potential for a wide range of applications, from bioremediation to tunable drug delivery systems. In the context of oral care, γ-PGA holds great promise in enamel demineralisation prevention. The salivary protein statherin has previously been shown to protect tooth enamel from acid dissolution and act as a reservoir for free calcium ions within oral cavities. Its superb enamel-binding capacity is attributed to the L-glutamic acid residues of this 5380 Da protein. In this study, γ-PGA was successfully synthesised from Bacillus subtilis natto cultivated on supplemented algae media and standard commercial media. The polymers obtained were tested for their potential to inhibit demineralisation of hydroxyapatite (HAp) when exposed to caries simulating acidic conditions. Formulations presenting 0.1, 0.25, 0.5, 0.75, 1, 2, 3 and 4% (w/v) γ-PGA concentration were assessed to determine the optimal conditions. Our data suggests that both the concentration and the molar mass of the γ-PGA were significant in enamel protection (p = 0.028 and p < 0.01 respectively). Ion Selective Electrode, combined with Fourier Transform Infra-Red studies, were employed to quantify enamel protection capacity of γ-PGA. All concentrations tested showed an inhibitory effect on the dissolution rate of calcium ions from hydroxyapatite, with 1% (wt) and 2% (wt) concentrations being the most effective. The impact of the average molar mass (M) on enamel dissolution was also investigated by employing commercial 66 kDa, 166 kDa, 440 kDa and 520 kDa γ-PGA fractions. All γ-PGA solutions adhered to the surface of HAp with evidence that this remained after 60 min of continuous acidic challenge. Inductively Coupled Plasma analysis showed a significant abundance of calcium ions associated with γ-PGA, which suggests that this material could also act as a responsive calcium delivery system. We have concluded that all γ-PGA samples tested (commercial and algae derived) display enamel protection capacity regardless of their concentration or average molar mass. However, we believe that γ-PGA D/L ratios might affect the binding more than its molar mass. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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13 pages, 2567 KiB

Open AccessArticle

Multifunctional PEG Carrier by Chemoenzymatic Synthesis for Drug Delivery Systems: In Memory of Professor Andrzej Dworak

by Judit E. Puskas, Gayatri Shrikhande, Eniko Krisch and Kristof Molnar

Polymers 2022, 14(14), 2900; https://doi.org/10.3390/polym14142900 - 16 Jul 2022

Cited by 2 | Viewed by 2279

Abstract

This paper describes the synthesis and characterization of new bivalent folate-targeted PEGylated doxorubicin (FA₂-dPEG-DOX₂) made by modular chemo-enzymatic processes using Candida antarctica lipase B (CALB) as a biocatalyst. Unique features are the use of monodisperse PEG (dPEG) and the [...] Read more.

This paper describes the synthesis and characterization of new bivalent folate-targeted PEGylated doxorubicin (FA₂-dPEG-DOX₂) made by modular chemo-enzymatic processes using Candida antarctica lipase B (CALB) as a biocatalyst. Unique features are the use of monodisperse PEG (dPEG) and the synthesis of thiol-functionalized folic acid yielding exclusive γ-conjugation of folic acid (FA) to dPEG. The polymer-based drug conjugate is built up by a series of transesterification and Michael addition reactions all catalyzed be CALB. In comparison with other methods in the literature, the modular approach with enzyme catalysis leads to selectivity, full conversion and high yield, and no transition metal catalyst residues. The intermediate product with four acrylate groups is an excellent platform for Michael-addition-type reactions for a wide variety of biologically active molecules. The chemical structures were confirmed by nuclear magnetic resonance spectroscopy (NMR). Flow cytometry analysis showed that, at 10 µM concentration, both free DOX and FA₂-dPEG-DOX₂ were taken up by 99.9% of triple-negative breast cancer cells in 2 h. Fluorescence was detected for 5 days after injecting compound IV into mice. Preliminary results showed that intra-tumoral injection seemed to delay tumor growth more than intravenous delivery. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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19 pages, 4866 KiB

Open AccessArticle

Chitosan-Based Therapeutic Systems for Superficial Candidiasis Treatment. Synergetic Activity of Nystatin and Propolis

by Andra-Cristina Humelnicu, Petrișor Samoilă, Corneliu Cojocaru, Raluca Dumitriu, Andra-Cristina Bostănaru, Mihai Mareș, Valeria Harabagiu and Bogdan C. Simionescu

Polymers 2022, 14(4), 689; https://doi.org/10.3390/polym14040689 - 11 Feb 2022

Cited by 9 | Viewed by 2948

Abstract

The paper deals with new approaches to chitosan (CS)-based antifungal therapeutic formulations designed to fulfill the requirements of specific applications. Gel-like formulations were prepared by mixing CS dissolved in aqueous lactic acid (LA) solution with nystatin (NYS) powder and/or propolis (PRO) aqueous solution [...] Read more.

The paper deals with new approaches to chitosan (CS)-based antifungal therapeutic formulations designed to fulfill the requirements of specific applications. Gel-like formulations were prepared by mixing CS dissolved in aqueous lactic acid (LA) solution with nystatin (NYS) powder and/or propolis (PRO) aqueous solution dispersed in glycerin, followed by water evaporation to yield flexible mesoporous (pore widths of 2–4 nm) films of high specific surfaces between 1 × 10³ and 1.7 × 10³ m²/g. Morphological evaluation of the antifungal films showed uniform dispersion and downsizing of NYS crystallites (with initial sizes up to 50 μm). Their mechanical properties were found to be close to those of soft tissues (Young’s modulus values between 0.044–0.025 MPa). The films presented hydration capacities in physiological condition depending on their composition, i.e., higher for NYS-charged (628%), as compared with PRO loaded films (118–129%). All NYS charged films presented a quick release for the first 10 min followed by a progressive increase of the release efficiency at 48.6%, for the samples containing NYS alone and decreasing values with increasing amount of PRO to 45.9% and 42.8% after 5 h. By in vitro analysis, the hydrogels with acidic pH values around 3.8 were proven to be active against Candida albicans and Candida glabrata species. The time-killing assay performed during 24 h on Candida albicans in synthetic vagina-simulative medium showed that the hydrogel formulations containing both NYS and PRO presented the faster slowing down of the fungal growth, from colony-forming unit (CFU)/mL of 1.24 × 10⁷ to CFU/mL < 10 (starting from the first 6 h). Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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16 pages, 3025 KiB

Open AccessArticle

Reversible Protein Capture and Release by Redox-Responsive Hydrogel in Microfluidics

by Chen Jiao, Franziska Obst, Martin Geisler, Yunjiao Che, Andreas Richter, Dietmar Appelhans, Jens Gaitzsch and Brigitte Voit

Polymers 2022, 14(2), 267; https://doi.org/10.3390/polym14020267 - 10 Jan 2022

Cited by 10 | Viewed by 6667

Abstract

Stimuli-responsive hydrogels have a wide range of potential applications in microfluidics, which has drawn great attention. Double cross-linked hydrogels are very well suited for this application as they offer both stability and the required responsive behavior. Here, we report the integration of poly( [...] Read more.

Stimuli-responsive hydrogels have a wide range of potential applications in microfluidics, which has drawn great attention. Double cross-linked hydrogels are very well suited for this application as they offer both stability and the required responsive behavior. Here, we report the integration of poly(N-isopropylacrylamide) (PNiPAAm) hydrogel with a permanent cross-linker (N,N′-methylenebisacrylamide, BIS) and a redox responsive reversible cross-linker (N,N′-bis(acryloyl)cystamine, BAC) into a microfluidic device through photopolymerization. Cleavage and re-formation of disulfide bonds introduced by BAC changed the cross-linking densities of the hydrogel dots, making them swell or shrink. Rheological measurements allowed for selecting hydrogels that withstand long-term shear forces present in microfluidic devices under continuous flow. Once implemented, the thiol-disulfide exchange allowed the hydrogel dots to successfully capture and release the protein bovine serum albumin (BSA). BSA was labeled with rhodamine B and functionalized with 2-(2-pyridyldithio)-ethylamine (PDA) to introduce disulfide bonds. The reversible capture and release of the protein reached an efficiency of 83.6% in release rate and could be repeated over 3 cycles within the microfluidic device. These results demonstrate that our redox-responsive hydrogel dots enable the dynamic capture and release of various different functionalized (macro)molecules (e.g., proteins and drugs) and have a great potential to be integrated into a lab-on-a-chip device for detection and/or delivery. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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32 pages, 8052 KiB

Open AccessArticle

Copolymer Involving 2-Hydroxyethyl Methacrylate and 2-Chloroquinyl Methacrylate: Synthesis, Characterization and In Vitro 2-Hydroxychloroquine Delivery Application

by Abeer Aljubailah, Wafa Nazzal Odis Alharbi, Ahmed S. Haidyrah, Tahani Saad Al-Garni, Waseem Sharaf Saeed, Abdelhabib Semlali, Saad M. S. Alqahtani, Ahmad Abdulaziz Al-Owais, Abdulnasser Mahmoud Karami and Taieb Aouak

Polymers 2021, 13(23), 4072; https://doi.org/10.3390/polym13234072 - 23 Nov 2021

Cited by 3 | Viewed by 2606

Abstract

The Poly(2-chloroquinyl methacrylate-co-2-hydroxyethyl methacrylate) (CQMA-co-HEMA) drug carrier system was prepared with different compositions through a free-radical copolymerization route involving 2-chloroquinyl methacrylate (CQMA) and 2-hydroxyethyl methacrylate) (HEMA) using azobisisobutyronitrile as the initiator. 2-Chloroquinyl methacrylate monomer (CQMA) was synthesized from 2-hydroxychloroquine [...] Read more.

The Poly(2-chloroquinyl methacrylate-co-2-hydroxyethyl methacrylate) (CQMA-co-HEMA) drug carrier system was prepared with different compositions through a free-radical copolymerization route involving 2-chloroquinyl methacrylate (CQMA) and 2-hydroxyethyl methacrylate) (HEMA) using azobisisobutyronitrile as the initiator. 2-Chloroquinyl methacrylate monomer (CQMA) was synthesized from 2-hydroxychloroquine (HCQ) and methacryloyl chloride by an esterification reaction using triethylenetetramine as the catalyst. The structure of the CQMA and CQMA-co-HEMA copolymers was confirmed by a CHN elementary analysis, Fourier transform infra-red (FTIR) and nuclear magnetic resonance (NMR) analysis. The absence of residual aggregates of HCQ or HCQMA particles in the copolymers prepared was confirmed by a differential scanning calorimeter (DSC) and XR-diffraction (XRD) analyses. The gingival epithelial cancer cell line (Ca9-22) toxicity examined by a lactate dehydrogenase (LDH) assay revealed that the grafting of HCQ onto PHEMA slightly affected (4.2–9.5%) the viability of the polymer carrier. The cell adhesion and growth on the CQMA-co-HEMA drug carrier specimens carried out by the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay revealed the best performance with the specimen containing 3.96 wt% HCQ. The diffusion of HCQ through the polymer matrix obeyed the Fickian model. The solubility of HCQ in different media was improved, in which more than 5.22 times of the solubility of HCQ powder in water was obtained. According to Belzer, the in vitro HCQ dynamic release revealed the best performance with the drug carrier system containing 4.70 wt% CQMA. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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18 pages, 5070 KiB

Open AccessArticle

The Influence of Hydrophobic Blocks of PEO-Containing Copolymers on Glyceryl Monooleate Lyotropic Liquid Crystalline Nanoparticles for Drug Delivery

by Aleksander Forys, Maria Chountoulesi, Barbara Mendrek, Tomasz Konieczny, Theodore Sentoukas, Marcin Godzierz, Aleksandra Kordyka, Costas Demetzos, Stergios Pispas and Barbara Trzebicka

Polymers 2021, 13(16), 2607; https://doi.org/10.3390/polym13162607 - 5 Aug 2021

Cited by 7 | Viewed by 2629

Abstract

The investigation of properties of amphiphilic block copolymers as stabilizers for non-lamellar lyotropic liquid crystalline nanoparticles represents a fundamental issue for the formation, stability and upgraded functionality of these nanosystems. The aim of this work is to use amphiphilic block copolymers, not studied [...] Read more.

The investigation of properties of amphiphilic block copolymers as stabilizers for non-lamellar lyotropic liquid crystalline nanoparticles represents a fundamental issue for the formation, stability and upgraded functionality of these nanosystems. The aim of this work is to use amphiphilic block copolymers, not studied before, as stabilizers of glyceryl monooleate 1-(cis-9-octadecenoyl)-rac-glycerol (GMO) colloidal dispersions. Nanosystems were prepared with the use of poly(ethylene oxide)-b-poly(lactic acid) (PEO-b-PLA) and poly(ethylene oxide)-b-poly(5-methyl-5-ethyloxycarbonyl-1,3-dioxan-2-one) (PEO-b-PMEC) block copolymers. Different GMO:polymer molar ratios lead to formulation of nanoparticles with different size and internal organization, depending on the type of hydrophobic block. Resveratrol was loaded into the nanosystems as a model hydrophobic drug. The physicochemical and morphological characteristics of the prepared nanosystems were investigated by dynamic light scattering (DLS), cryogenic transmission electron microscopy (cryo-TEM), fast Fourier transform (FFT) analysis and X-ray diffraction (XRD). The studies allowed the description of the lyotropic liquid crystalline nanoparticles and evaluation of impact of copolymer composition on these nanosystems. The structures formed in GMO:block copolymer colloidal dispersions were compared with those discussed previously. The investigations broaden the toolbox of polymeric stabilizers for the development of this type of hybrid polymer/lipid nanostructures. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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14 pages, 1596 KiB

Open AccessArticle

HPMA-Based Polymer Conjugates for Repurposed Drug Mebendazole and Other Imidazole-Based Therapeutics

by Martin Studenovský, Anna Rumlerová, Libor Kostka and Tomáš Etrych

Polymers 2021, 13(15), 2530; https://doi.org/10.3390/polym13152530 - 30 Jul 2021

Cited by 3 | Viewed by 2672

Abstract

Recently, the antitumor potential of benzimidazole anthelmintics, such as mebendazole and its analogues, have been reported to have minimal side effects, in addition to their well-known anti-parasitic abilities. However, their administration is strongly limited owing to their extremely poor solubility, which highly depletes [...] Read more.

Recently, the antitumor potential of benzimidazole anthelmintics, such as mebendazole and its analogues, have been reported to have minimal side effects, in addition to their well-known anti-parasitic abilities. However, their administration is strongly limited owing to their extremely poor solubility, which highly depletes their overall bioavailability. This study describes the design, synthesis, and physico-chemical properties of polymer-mebendazole nanomedicines for drug repurposing in cancer therapy. The conjugation of mebendazole to water-soluble and biocompatible polymer carrier was carried out via biodegradable bond, relying on the hydrolytic action of lysosomal hydrolases for mebendazole release inside the tumor cells. Five low-molecular-weight mebendazole derivatives, differing in their inner structure, and two polymer conjugates differing in their linker structure, were synthesized. The overall synthetic strategy was designed to enable the modification and polymer conjugation of most benzimidazole-based anthelmintics, such as albendazole, fenbendazole or albendazole, besides the mebendazole. Furthermore, the described methodology may be suitable for conjugation of other biologically active compounds with a heterocyclic N-H group in their molecules. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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15 pages, 4114 KiB

Open AccessEditor’s ChoiceArticle

PnBA-b-PNIPAM-b-PDMAEA Thermo-Responsive Triblock Terpolymers and Their Quaternized Analogs as Gene and Drug Delivery Vectors

by Athanasios Skandalis, Dimitrios Selianitis and Stergios Pispas

Polymers 2021, 13(14), 2361; https://doi.org/10.3390/polym13142361 - 19 Jul 2021

Cited by 9 | Viewed by 3551

Abstract

In this work, the ability of thermo-responsive poly [butyl acrylate-b-N-isopropylacrylamide-b-2-(dimethylamino) ethyl acrylate] (PnBA-b-PNIPAM-b-PDMAEA) triblock terpolymer self-assemblies, as well as of their quaternized analogs (PnBA-b-PNIPAM-b-QPDMAEA), to form polyplexes with DNA through electrostatic interactions was examined. Terpolymer/DNA polyplexes were prepared in three different amine over [...] Read more.

In this work, the ability of thermo-responsive poly [butyl acrylate-b-N-isopropylacrylamide-b-2-(dimethylamino) ethyl acrylate] (PnBA-b-PNIPAM-b-PDMAEA) triblock terpolymer self-assemblies, as well as of their quaternized analogs (PnBA-b-PNIPAM-b-QPDMAEA), to form polyplexes with DNA through electrostatic interactions was examined. Terpolymer/DNA polyplexes were prepared in three different amine over phosphate group ratios (N/P), and linear DNA with a 2000 base pair length was used. In aqueous solutions, the terpolymers formed aggregates of micelles with mixed PNIPAM/(Q)PDMAEA coronas and PnBA cores. The PnBA-b-PNIPAM-b-PDMAEA terpolymers’ micellar aggregates were also examined as carriers for the model hydrophobic drug curcumin (CUR). The complexation ability of the terpolymer with DNA was studied by UV–Vis spectroscopy and fluorescence spectroscopy by investigating ethidium bromide quenching. Fluorescence was also used for the determination of the intrinsic fluorescence of the CUR-loaded micellar aggregates. The structural characteristics of the polyplexes and the CUR-loaded aggregates were investigated by dynamic and electrophoretic light scattering techniques. Polyplexes were found to structurally respond to changes in solution temperature and ionic strength, while the intrinsic fluorescence of encapsulated CUR was increased at temperatures above ambient. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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10 pages, 6235 KiB

Open AccessArticle

Citrate-Coated Magnetic Polyethyleneimine Composites for Plasmid DNA Delivery into Glioblastoma

by Ken Cham-Fai Leung, Kathy W. Y. Sham, Josie M. Y. Lai, Yi-Xiang J. Wang, Chi-Hin Wong and Christopher H. K. Cheng

Polymers 2021, 13(14), 2228; https://doi.org/10.3390/polym13142228 - 6 Jul 2021

Cited by 5 | Viewed by 2519

Abstract

Several ternary composites that are based on branched polyethyleneimine (bPEI 25 kDa, polydispersity 2.5, 0.1 or 0.2 ng), citrate-coated ultrasmall superparamagnetic iron oxide nanoparticles (citrate-NPs, 8–10 nm, 0.1, 1.0, or 2.5 µg), and reporter circular plasmid DNA pEGFP-C1 or pRL-CMV (pDNA 0.5 µg) [...] Read more.

Several ternary composites that are based on branched polyethyleneimine (bPEI 25 kDa, polydispersity 2.5, 0.1 or 0.2 ng), citrate-coated ultrasmall superparamagnetic iron oxide nanoparticles (citrate-NPs, 8–10 nm, 0.1, 1.0, or 2.5 µg), and reporter circular plasmid DNA pEGFP-C1 or pRL-CMV (pDNA 0.5 µg) were studied for optimization of the best composite for transfection into glioblastoma U87MG or U138MG cells. The efficiency in terms of citrate-NP and plasmid DNA gene delivery with the ternary composites could be altered by tuning the bPEI/citrate-NP ratios in the polymer composites, which were characterized by Prussian blue staining, in vitro magnetic resonance imaging as well as green fluorescence protein and luciferase expression. Among the composites prepared, 0.2 ng bPEI/0.5 μg pDNA/1.0 µg citrate-NP ternary composite possessed the best cellular uptake efficiency. Composite comprising 0.1 ng bPEI/0.5 μg pDNA/0.1 μg citrate-NP gave the optimal efficiency for the cellular uptake of the two plasmid DNAs to the nucleus. The best working bPEI concentration range should not exceed 0.2 ng/well to achieve a relatively low cytotoxicity. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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Review

Jump to: Editorial, Research

36 pages, 13192 KiB

Open AccessReview

Polyesters and Polyester Nano- and Microcarriers for Drug Delivery

by Stanislaw Slomkowski, Teresa Basinska, Mariusz Gadzinowski and Damian Mickiewicz

Polymers 2024, 16(17), 2503; https://doi.org/10.3390/polym16172503 - 3 Sep 2024

Viewed by 1219

Abstract

Many therapies require the transport of therapeutic compounds or substances encapsulated in carriers that reduce or, if possible, eliminate their direct contact with healthy tissue and components of the immune system, which may react to them as something foreign and dangerous to the [...] Read more.

Many therapies require the transport of therapeutic compounds or substances encapsulated in carriers that reduce or, if possible, eliminate their direct contact with healthy tissue and components of the immune system, which may react to them as something foreign and dangerous to the patient’s body. To date, inorganic nanoparticles, solid lipids, micelles and micellar aggregates, liposomes, polymeric micelles, and other polymer assemblies were tested as drug carriers. Specifically, using polymers creates a variety of options to prepare nanocarriers tailored to the chosen needs. Among polymers, aliphatic polyesters are a particularly important group. The review discusses controlled synthesis of poly(β-butyrolactone)s, polylactides, polyglycolide, poly(ε-caprolactone), and copolymers containing polymacrolactone units with double bonds suitable for preparation of functionalized nanoparticles. Discussed are syntheses of aliphatic polymers with controlled molar masses ranging from a few thousand to 10⁶ and, in the case of polyesters with chiral centers in the chains, with controlled microstructure. The review presents also a collection of methods useful for the preparation of the drug-loaded nanocarriers: classical, developed and mastered more recently (e.g., nanoprecipitation), and forgotten but still with great potential (by the direct synthesis of the drug-loaded nanoparticles in the process comprising monomer and drug). The article describes also in-vitro and model in-vivo studies for the brain-targeted drugs based on polyester-containing nanocarriers and presents a brief update on the clinical studies and the polyester nanocarrier formulation approved for application in the clinics in South Korea for the treatment of breast, lung, and ovarian cancers. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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51 pages, 6547 KiB

Open AccessReview

Recent Advances in the Application of ATRP in the Synthesis of Drug Delivery Systems

by Matylda Szewczyk-Łagodzińska, Andrzej Plichta, Maciej Dębowski, Sebastian Kowalczyk, Anna Iuliano and Zbigniew Florjańczyk

Polymers 2023, 15(5), 1234; https://doi.org/10.3390/polym15051234 - 28 Feb 2023

Cited by 13 | Viewed by 4723

Abstract

Advances in atom transfer radical polymerization (ATRP) have enabled the precise design and preparation of nanostructured polymeric materials for a variety of biomedical applications. This paper briefly summarizes recent developments in the synthesis of bio-therapeutics for drug delivery based on linear and branched [...] Read more.

Advances in atom transfer radical polymerization (ATRP) have enabled the precise design and preparation of nanostructured polymeric materials for a variety of biomedical applications. This paper briefly summarizes recent developments in the synthesis of bio-therapeutics for drug delivery based on linear and branched block copolymers and bioconjugates using ATRP, which have been tested in drug delivery systems (DDSs) over the past decade. An important trend is the rapid development of a number of smart DDSs that can release bioactive materials in response to certain external stimuli, either physical (e.g., light, ultrasound, or temperature) or chemical factors (e.g., changes in pH values and/or environmental redox potential). The use of ATRPs in the synthesis of polymeric bioconjugates containing drugs, proteins, and nucleic acids, as well as systems applied in combination therapies, has also received considerable attention. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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20 pages, 3417 KiB

Open AccessReview

Recent Advances in Biomedical Applications of Polymeric Nanoplatform Assisted with Two-Photon Absorption Process

by Subramaniyan Ramasundaram, Sivasangu Sobha, Gurusamy Saravanakumar and Tae Hwan Oh

Polymers 2022, 14(23), 5134; https://doi.org/10.3390/polym14235134 - 25 Nov 2022

Cited by 5 | Viewed by 2394

Abstract

Polymers are well-recognized carriers useful for delivering therapeutic drug and imaging probes to the target specified in the defined pathophysiological site. The functional drug molecules and imaging agents were chemically attached or physically loaded in the carrier polymer matrix via cleavable spacers. Using [...] Read more.

Polymers are well-recognized carriers useful for delivering therapeutic drug and imaging probes to the target specified in the defined pathophysiological site. The functional drug molecules and imaging agents were chemically attached or physically loaded in the carrier polymer matrix via cleavable spacers. Using appropriate targeting moieties, these polymeric carriers (PCs) loaded with functional molecules were designed to realize target-specific delivery at the cellular level. The biodistribution of these carriers can be tracked using imaging agents with suitable imaging techniques. The drug molecules can be released by cleaving the spacers either by endogenous stimuli (e.g., pH, redox species, glucose level and enzymes) at the targeted physiological site or exogenous stimuli (e.g., light, electrical pulses, ultrasound and magnetism). Recently, two-photon absorption (2PA)-mediated drug delivery and imaging has gained significant attention because TPA from near-infrared light (700–950 nm, NIR) renders light energy similar to the one-photon absorption from ultraviolet (UV) light. NIR has been considered biologically safe unlike UV, which is harmful to soft tissues, cells and blood vessels. In addition to the heat and reactive oxygen species generating capability of 2PA molecules, 2PA-functionalized PCs were also found to be useful for treating diseases such as cancer by photothermal and photodynamic therapies. Herein, insights attained towards the design, synthesis and biomedical applications of 2PA-activated PCs are reviewed. In particular, specific focus is provided to the imaging and drug delivery applications with a special emphasis on multi-responsive platforms. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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18 pages, 2230 KiB

Open AccessReview

Polyglycerols as Multi-Functional Platforms: Synthesis and Biomedical Applications

by Paria Pouyan, Mariam Cherri and Rainer Haag

Polymers 2022, 14(13), 2684; https://doi.org/10.3390/polym14132684 - 30 Jun 2022

Cited by 23 | Viewed by 5328

Abstract

The remarkable and unique characteristics of polyglycerols (PG) have made them an attractive candidate for many applications in the biomedical and pharmaceutical fields. The presence of multiple hydroxy groups on the flexible polyether backbone not only enables the further modification of the PG [...] Read more.

The remarkable and unique characteristics of polyglycerols (PG) have made them an attractive candidate for many applications in the biomedical and pharmaceutical fields. The presence of multiple hydroxy groups on the flexible polyether backbone not only enables the further modification of the PG structure but also makes the polymer highly water-soluble and results in excellent biocompatibility. In this review, the polymerization routes leading to PG with different architectures are discussed. Moreover, we discuss the role of these polymers in different biomedical applications such as drug delivery systems, protein conjugation, and surface modification. Full article

(This article belongs to the Special Issue Polymeric Carriers for Delivery Systems in Biomedical Applications – in Memory of Professor Andrzej Dworak)

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