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1.
Int J Biol Macromol ; 265(Pt 2): 131027, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38518936

RESUMO

Lung infections, such as: pneumonia, chronic obstructive cystic fibrosis, tuberculosis are generally caused by viruses, bacteria and fungi. As these infections are very difficult to treat, new therapeutic approaches are investigated in order to maximize the efficiency of the treatment and to reduce the major complications that can occur. The main objective of this study was focused on the preparation of drug-loaded peptides-functionalized microcapsules, obtained by a double emulsion, based on carboxylated chitosan (CMCS), poly(vinyl alcohol) (PVA) and an activator [4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride] (DMT-MM), for the dual active targeting and treatment of pulmonary infections. The microcapsules were functionalized on the surface with both CGSPGWVRC and indolicidin (IN) peptides, as effective ligands for the active targeting of both alveolar capillary endothelial cells and bacterial cells. FTIR spectroscopy confirmed the formation of ester and amide bonds into the structure of prepared microcapsules. Microcapsules diameter varied between 893 and 965 nm. The swelling degree in PBS, at pH 7.4, ranged between 1760 %- 2100 %. All the analyzed samples showed hemolysis degrees lower than 2 %, which demonstrated their non-hemolytic character. Evaluation of the impact of microcapsules on WI-38 normal human lung cells and RAW 264.7 mouse macrophages revealed a non-toxic or slightly cytotoxic effect. Internalization assay proved that microcapsules were localized at intracellular level.


Assuntos
Quitosana , Pneumonia , Animais , Camundongos , Humanos , Quitosana/química , Cápsulas/química , Células Endoteliais , Peptídeos , Pulmão
2.
Polymers (Basel) ; 16(2)2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38257005

RESUMO

Degradable polymers (both biomacromolecules and several synthetic polymers) for biomedical applications have been promising very much in the recent past due to their low cost, biocompatibility, flexibility, and minimal side effects. Here, we present an overview with updated information on natural and synthetic degradable polymers where a brief account on different polysaccharides, proteins, and synthetic polymers viz. polyesters/polyamino acids/polyanhydrides/polyphosphazenes/polyurethanes relevant to biomedical applications has been provided. The various approaches for the transformation of these polymers by physical/chemical means viz. cross-linking, as polyblends, nanocomposites/hybrid composites, interpenetrating complexes, interpolymer/polyion complexes, functionalization, polymer conjugates, and block and graft copolymers, are described. The degradation mechanism, drug loading profiles, and toxicological aspects of polymeric nanoparticles formed are also defined. Biomedical applications of these degradable polymer-based biomaterials in and as wound dressing/healing, biosensors, drug delivery systems, tissue engineering, and regenerative medicine, etc., are highlighted. In addition, the use of such nano systems to solve current drug delivery problems is briefly reviewed.

3.
Int J Mol Sci ; 24(22)2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-38003441

RESUMO

The definition of the term biopolymer is often controversial, and there is no clear distinction between "biopolymers", "bioplastics", and "bio-based polymers" [...].


Assuntos
Polímeros , Biopolímeros
4.
Pharmaceutics ; 15(9)2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37765209

RESUMO

Hydrogels are a favorable alternative to accelerate the burn wound healing process and skin regeneration owing to their capability of absorbing contaminated exudates. The bacterial infections that occur in burn wounds might be treated using different topically applied materials, but bacterial resistance to antibiotics has become a major problem worldwide. Therefore, the use of non-antibiotic treatments represents a major interest in current research. In this study, new antibiocomposite hydrogels with anti-inflammatory and antimicrobial properties based on hyaluronic acid (HA) and sodium alginate (AG) were obtained using 4-(4,6-dimethoxy-1,3,5-triazinyl-2)-4-methylmorpholinium chloride as an activator. The combination of Ibuprofen, a non-steroidal anti-inflammatory drug commonly used to reduce inflammation, fever and pain in the body, with zinc oxide nanoparticles (ZnO NPs) was used in this study aimed at creating a complex hydrogel with anti-inflammatory and antimicrobial action and capable of improving the healing process of wounds caused by burns. FTIR spectra confirmed the cross-linking of AG with HA as well as the successful incorporation of ZnO NPs. Using electronic microscopy, it was noticed that the morphology of hydrogels is influenced by the incorporation of ZnO nanoparticles. Moreover, the incorporation of ZnO nanoparticles into hydrogels also has an influence on the swelling behavior at both pH 7.4 and 5.4. In fact, the swelling rate is lower when the amounts of the activator, HA and ZnO NPs are high. A drug release rate of almost 100% was observed for hydrogels without ZnO NPs, whereas the addition of nanoparticles to hydrogels led to a decrease in the release rate to 68% during 24 h. Cellular viability tests demonstrated the non-cytotoxic behavior of the hydrogels without the ZnO NPs, whereas a weak to moderate cytotoxic effect was noticed for hydrogels with ZnO NPs. The hydrogels containing 4% and 5% ZnO NPs, respectively, showed good antimicrobial activity against the S. aureus strain. These preliminary data prove that these types of hydrogels can be of interest as biomaterials for the treatment of burn wounds.

5.
Molecules ; 28(12)2023 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-37375250

RESUMO

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.


Assuntos
Hidrogéis , alfa-Amilases Pancreáticas , Suínos , Estabilidade Enzimática , Enzimas Imobilizadas/química , alfa-Amilases/metabolismo , Temperatura , Íons , Amido , Concentração de Íons de Hidrogênio , Animais
6.
Materials (Basel) ; 16(7)2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37049223

RESUMO

This study focuses on the retting effect on the mechanical properties of flax biobased materials. For the technical fiber, a direct link was established between the biochemical alteration of technical flax and their mechanical properties. In function of the retting level, technical fibers appeared smoother and more individualized; nevertheless, a decrease in the ultimate modulus and maximum stress was recorded. A biochemical alteration was observed as the retting increased (a decrease in the soluble fraction from 10.4 ± 0.2 to 4.5 ± 1.2% and an increase in the holocellulose fractions). Regarding the mechanical behavior of biocomposites manufactured by thermocompression, a non-elastic behavior was observed for the tested samples. Young moduli (E1 and E2) gradually increased with retting. The retting effect was more pronounced when a normalization was performed (according to the fiber volume and porosity). A 40% increase in elastic modulus could be observed between under-retting (-) and over-retting (+). Moreover, the porosity content (Vp) increased overall with fiber content. Setup 3, with optimized processing parameters, was the most desirable processing protocol because it allowed the highest fiber fraction (Vf) for the lowest Vp.

7.
Int J Pharm ; 639: 122971, 2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37105242

RESUMO

Polymeric microcapsules are extensively investigated as drug delivery systems for a broad range of applications. In the present study, Dexamethasone-loaded carboxylated chitosan (CCS)/poly (vinyl alcohol) (PVA)-based microcapsules were prepared in view of their potential administration by inhalation for the treatment of lung diseases. The crosslinking between PVA and CCS was activated by [4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride] (DMT-MM) and the FTIR results proved the formation of ester bonds between the two polymers. The sizes of the obtained microcapsules are influenced by the ratio between the polymers but also by the concentration of the DMT-MM activator. Moreover, the amount of PVA in the system has an important influence on swelling degree, encapsulation efficiency, drug release degree, biodegradation and protein adsorption. The sample with the highest amount of PVA has the highest crosslinking density and thus the lowest swelling degree and encapsulation efficiency. However, an encapsulation degree of 61.3% was obtained for the sample MCP-6 with the lowest PVA content. The same sample showed the lowest BSA adsorption. A controlled and sustained Dexamethasone release of around 90% was observed in PBS at pH 7.4 and 37 °C during 24 h. All the obtained samples were hemocompatibles and thus can be used as efficient drug delivery systems.


Assuntos
Quitosana , Polímeros , Cápsulas , Emulsões , Polímeros/química , Álcool de Polivinil/química , Dexametasona , Quitosana/química
8.
Polymers (Basel) ; 15(8)2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-37112047

RESUMO

In this study we have employed a polymer processing method based on solvent vapor annealing in order to condense relatively large amounts of solvent vapors onto thin films of block copolymers and thus to promote their self-assembly into ordered nanostructures. As revealed by the atomic force microscopy, a periodic lamellar morphology of poly(2-vinylpyridine)-b-polybutadiene and an ordered morphology comprised of hexagonally-packed structures made of poly(2-vinylpyridine)-b-poly(cyclohexyl methacrylate) were both successfully generated on solid substrates for the first time.

9.
Polymers (Basel) ; 15(4)2023 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-36850078

RESUMO

The development of accurate drug delivery systems is one of the main challenges in the biomedical field. A huge variety of structures, such as vesicles, nanoparticles, and nanofibers, have been proposed as carriers for bioactive agents, aiming for precision in administration and dosage, safety, and bioavailability. This review covers the use of electrohydrodynamic techniques both for the immobilization and for the synthesis of vesicles in a non-conventional way. The state of the art discusses the most recent advances in this field as well as the advantages and limitations of electrospun and electrosprayed amphiphilic structures as precursor templates for the in situ vesicle self-assembly. Finally, the perspectives and challenges of combined strategies for the development of advanced structures for the delivery of bioactive agents are analyzed.

10.
Int J Mol Sci ; 24(3)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36768226

RESUMO

The quest for sustainable biomaterials with excellent biocompatibility and tailorable properties has put polyhydroxyalkanoates (PHAs) into the research spotlight. However, high production costs and the lack of bioactivity limit their market penetration. To address this, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was combined with a bacterial pigment with strong anticancer activity, prodigiosin (PG), to obtain functionally enhanced PHBV-based biomaterials. The samples were produced in the form of films 115.6-118.8 µm in thickness using the solvent casting method. The effects of PG incorporation on the physical properties (morphology, biopolymer crystallinity and thermal stability) and functionality of the obtained biomaterials were investigated. PG has acted as a nucleating agent, in turn affecting the degree of crystallinity, thermal stability and morphology of the films. All samples with PG had a more organized internal structure and higher melting and degradation temperatures. The calculated degree of crystallinity of the PHBV copolymer was 53%, while the PG1, PG3 and PG3 films had values of 64.0%, 63.9% and 69.2%, respectively. Cytotoxicity studies have shown the excellent anticancer activity of films against HCT116 (colon cancer) cells, thus advancing PHBV biomedical application potential.


Assuntos
Poliésteres , Poli-Hidroxialcanoatos , Poliésteres/química , Prodigiosina/farmacologia , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/química
11.
Materials (Basel) ; 16(2)2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36676546

RESUMO

The effect of hydroxyapatite (HAp) synthesized by the chemical precipitation process on the morphology and properties of composites based on poly(lactic acid) (PLA) was investigated at various filler content ratios, i.e., 5, 10 and 15 wt%. Both neat PLA and PLA-based composites were first prepared using the solvent casting method, followed by melt compounding in an internal mixer, whereas tensile specimens were obtained by thermo-compression. The study revealed that the addition of 5 wt% of HAp into the PLA led to a slight improvement in both the thermal stability and tensile properties of the composite material in comparison with neat PLA and other composite samples. Indeed, the values of the tensile strength and modulus increased from approximately 61 MPa and 2.9 GPa for the neat PLA to almost 64 MPa and 3.057 GPa for the composite sample, respectively. Moreover, the degradation temperature at a 5 wt% mass loss also increased by almost 5 °C compared to other samples, due probably to a finer dispersion of the HAp particles in the PLA, as observed under a scanning electron microscope. Furthermore, the FT-IR spectra displayed some changes in the chemical structure of the PLA/HAp (5 wt%), indicating the occurrence of filler-matrix interactions. At a higher filler content ratio, a decrease in the properties of the PLA/HAp composites was observed, being more pronounced at 15 wt%. The PLA composite containing 5 wt% HAp presents the best compromise among the investigated properties. The study highlighted the possibility of using HAp without any prior surface treatment as a reinforcement in PLA composite materials.

12.
Pharmaceutics ; 15(1)2023 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-36678912

RESUMO

Stimuli-responsive copolymers are of great interest for targeted drug delivery. This study reports on a controllable post-polymerization quaternization with 2-bromomethyl-4-fluorophenylboronic acid of the poly(4-vinyl pyridine) (P4VP) block of a common poly(styrene)-b-poly(4-vinyl pyridine)-b-poly(ethylene oxide) (SVE) triblock terpolymer in order to achieve a selective responsivity to various diols. For this purpose, a reproducible method was established for P4VP block quaternization at a defined ratio, confirming the reaction yield by 11B, 1H NMR. Then, a reproducible self-assembly protocol is designed for preparing stable micelles from functionalized stimuli-responsive triblock terpolymers, which are characterized by light scattering and by cryogenic transmission electron microscopy. In addition, UV-Vis spectroscopy is used to monitor the boron-ester bonding and hydrolysis with alizarin as a model drug and to study encapsulation and release of this drug, induced by sensing with three geminal diols: fructose, galactose and ascorbic acid. The obtained results show that only the latter, with the vicinal diol group on sp2-hybridized carbons, was efficient for alizarin release. Therefore, the post-polymerization method for triblock terpolymer functionalization presented in this study allows for preparation of specific stimuli-responsive systems with a high potential for targeted drug delivery, especially for cancer treatment.

13.
Int J Mol Sci ; 24(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36674566

RESUMO

Synthetic poly(amino acids) are a unique class of macromolecules imitating natural polypeptides and are widely considered as carriers for drug and gene delivery. In this work, we synthesized, characterized and studied the properties of amphiphilic copolymers obtained by the post-polymerization modification of poly(α,L-glutamic acid) with various hydrophobic and basic L-amino acids and D-glucosamine. The resulting glycopolypeptides were capable of forming nanoparticles that exhibited reduced macrophage uptake and were non-toxic to human lung epithelial cells (BEAS-2B). Moreover, the developed nanoparticles were suitable for loading hydrophobic cargo. In particular, paclitaxel nanoformulations had a size of 170-330 nm and demonstrated a high cytostatic efficacy against human lung adenocarcinoma (A549). In general, the obtained nanoparticles were comparable in terms of their characteristics and properties to those based on amphiphilic (glyco)polypeptides obtained by copolymerization methods.


Assuntos
Ácido Glutâmico , Nanopartículas , Humanos , Polimerização , Peptídeos/química , Portadores de Fármacos/química , Nanopartículas/química , Aminoácidos , Sistemas de Liberação de Medicamentos/métodos
14.
Polymers (Basel) ; 14(21)2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36365696

RESUMO

Self-assembly of amphiphilic block copolymers display a multiplicity of nanoscale periodic patterns proposed as a dominant tool for the 'bottom-up' fabrication of nanomaterials with different levels of ordering. The present review article focuses on the recent updates to the self-association of amphiphilic block copolymers in aqueous media into varied core-shell morphologies. We briefly describe the block copolymers, their types, microdomain formation in bulk and micellization in selective solvents. We also discuss the characteristic features of block copolymers nanoaggregates viz., polymer micelles (PMs) and polymersomes. Amphiphilic block copolymers (with a variety of hydrophobic blocks and hydrophilic blocks; often polyethylene oxide) self-assemble in water to micelles/niosomes similar to conventional nonionic surfactants with high drug loading capacity. Double hydrophilic block copolymers (DHBCs) made of neutral block-neutral block or neutral block-charged block can transform one block to become hydrophobic under the influence of a stimulus (physical/chemical/biological), and thus induced amphiphilicity and display self-assembly are discussed. Different kinds of polymer micelles (viz. shell and core-cross-linked, core-shell-corona, schizophrenic, crew cut, Janus) are presented in detail. Updates on polymerization-induced self-assembly (PISA) and crystallization-driven self-assembly (CDSA) are also provided. Polyion complexes (PICs) and polyion complex micelles (PICMs) are discussed. Applications of these block copolymeric micelles and polymersomes as nanocarriers in drug delivery systems are described.

15.
Polymers (Basel) ; 14(18)2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36145879

RESUMO

Biodegradable polymers contain chains that are hydrolytically or enzymatically cleaved, resulting in soluble degradation products. Biodegradability is particularly desired in biomedical applications, in which degradation of the polymer ensures clearance from the body and eliminates the need for retrieval or explant. In this study, a homologues series of poly(ε-caprolactone)-b-poly(ethylene adipate)-b-poly(ε-caprolactone) (PCL-b-PEA-b-PCL) block copolymers, with constant PEA molar mass and different PCL sequence lengths was obtained. The starting point of these copolymers was a dihydroxy-PEA precursor with a molar mass (Mn) of 2500 g/mol. Mn values of the PCL varied between 1000 and 10,000 g/mol. Both the precursors and the copolymers were characterized using different physicochemical methods, such as: NMR, SEC, Maldi-TOFF, DSC, and ATG. The molecular characteristics of the copolymers were in a direct correlation with the sequence length of the PCL. Enzymatic degradability studies were also conducted by using cell-free extract containing Pseudomonas aeruginosa PAO1 for 10 and 21 days, and it appeared that the presence of the PEA central sequence has an important influence on the biodegradability of the copolymer samples. In fact, copolymer PCL7000-PEA2500-PCL7000 had a weight loss of around 50% after 10 days whereas the weight loss of the homopolymer PCL, with a similar Mn of 14,000 g/mol, was only 6%. The results obtained in this study indicate that these copolymer samples can be further used for the preparation of drug delivery systems with modulated biodegradability.

16.
Nanomaterials (Basel) ; 12(15)2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35957007

RESUMO

Volatile organic compounds (VOCs) are in the vapor state in the atmosphere and are considered pollutants. Density functional theory (DFT) calculations with the wb97xd exchange correlation functional and the 6-311+G(d,p) basis set are carried out to explore the potential possibility of palladium-doped single-walled carbon nanotubes (Pd/SWCNT-V), serving as the resource for detecting and/or adsorbing acetonitrile (ACN), styrene (STY), and perchloroethylene (PCE) molecules as VOCs. The suggested adsorbent in this study is discussed with structural parameters, frontier molecular orbital theory, molecular electrical potential surfaces (MEPSs), natural bond orbital (NBO) analyses, and the density of states. Furthermore, following the Bader theory of atoms in molecules (AIM), the topological properties of the electron density contributions for intermolecular interactions are analyzed. The obtained results show efficient VOC loading via a strong chemisorption process with a mean adsorption energy of -0.94, -1.27, and -0.54 eV for ACN, STY, and PCE, respectively. Our results show that the Pd/SWCNT-V can be considered a good candidate for VOC removal from the environment.

17.
Int J Mol Sci ; 23(16)2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-36012646

RESUMO

Glaucoma is the second leading cause of blindness in the world. Despite the fact that many treatments are currently available for eye diseases, the key issue that arises is the administration of drugs for long periods of time and the increased risk of inflammation, but also the high cost of eye surgery. Consequently, numerous daily administrations are required, which reduce patient compliance, and even in these conditions, the treatment of eye disease is too ineffective. Micellar polymers are core-shell nanoparticles formed by the self-assembly of block or graft copolymers in selective solvents. In the present study, polymeric micelles (PMs) were obtained by dialysis from smart biocompatible poly(ε-caprolactone)-poly(N-vinylcaprolactam-co-N-vinylpyrrolidone) [PCL-g-P(NVCL-co-NVP)] graft copolymers. Two copolymers with different molar masses were studied, and a good correlation was noted between the micellar sizes and the total degree of polymerisation (DPn) of the copolymers. The micelles formed by Cop A [PCL120-g-P(NVCL507-co-NVP128)], with the lowest total DPn, have a Z-average value of 39 nm, whereas the micellar sizes for Cop B [PCL120-g-P(NVCL1253-co-NVP139)] are around 47 nm. These PMs were further used for the encapsulation of two drugs with applications for the treatment of eye diseases. After the encapsulation of Dorzolamide, a slight increase in micellar sizes was noted, whereas the encapsulation of Indomethacin led to a decrease in these sizes. Using dynamic light scattering, it was proved that both free and drug-loaded PMs are stable for 30 days of storage at 4 °C. Moreover, in vitro biological tests demonstrated that the obtained PMs are both haemo- and cytocompatible and thus can be used for further in vivo tests. The designed micellar system proved its ability to release the encapsulated drugs in vitro, and the results obtained were validated by in vivo tests carried out on experimental animals, which proved its high effectiveness in reducing intraocular pressure.


Assuntos
Glaucoma , Micelas , Animais , Portadores de Fármacos , Glaucoma/tratamento farmacológico , Poliésteres , Polietilenoglicóis , Polímeros , Diálise Renal
18.
Polymers (Basel) ; 14(15)2022 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-35893968

RESUMO

Bacterial oral diseases are chronic, and, therefore, require appropriate treatment, which involves various forms of administration and dosing of the drug. However, multimicrobial resistance is an increasing issue, which affects the global health system. In the present study, a commercial amphiphilic copolymer, Pluronic F127, was used for the encapsulation of 1-(5'-nitrobenzimidazole-2'-yl-sulphonyl-acetyl)-4-aryl-thiosemicarbazide, which is an original active pharmaceutical ingredient (API) previously synthesized and characterized by our group, at different copolymer/API weight ratios. The obtained micellar systems, with sizes around 20 nm, were stable during 30 days of storage at 4 °C, without a major increase of the Z-average sizes. As expected, the drug encapsulation and loading efficiencies varied with the copolymer/API ratio, the highest values of 84.8 and 11.1%, respectively being determined for the F127/API = 10/1 ratio. Moreover, in vitro biological tests have demonstrated that the obtained polymeric micelles (PMs) are both hemocompatible and cytocompatible. Furthermore, enhanced inhibition zones of 36 and 20 mm were observed for the sample F127/API = 2/1 against S. aureus and E. coli, respectively. Based on these encouraging results, it can be admitted that these micellar systems can be an efficient alternative for the treatment of bacterial oral diseases, being suitable either by injection or by a topical administration.

19.
Polymers (Basel) ; 14(9)2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35566980

RESUMO

Drug delivery is an important field of nanomedicine, and its aim is to deliver specific active substances to a precise site of action in order to produce a desired pharmacological effect. In the present study nanocapsules were obtained by a process of interfacial condensation between chitosan (dissolved in the aqueous phase) and poly(N-vinyl pyrrolidone-alt-itaconic anhydride), a highly reactive copolymer capable of easily opening the anhydride ring under the action of amine groups of chitosan. The formed amide bonds led to the formation of a hydrogel membrane. The morphology of the obtained nanocapsules, their behavior in aqueous solution of physiological pH, and their ability to encapsulate and release a model drug can be modulated by the parameters of the synthesis process, such as the molar ratio between functional groups of polymers and the ratio of the phases in which the polymers are solubilized. Although a priori both polymers are biocompatible, this paper reports the results of a very detailed in vivo study conducted on experimental animals which have received the obtained nanocapsules by three administration routes-intraperitoneal, subcutaneous, and oral. The organs taken from the animals' kidney, liver, spleen, and lung and analyzed histologically demonstrated the ability of nanocapsules to stimulate the monocytic macrophage system without producing inflammatory changes. Moreover, their in vivo behavior has been shown to depend not only on the route of administration but also on the interaction with the cells of the organs with which they come into contact. The results clearly argue the biocompatibility of nanocapsules and hence the possibility of their safe use in biomedical applications.

20.
Nanomaterials (Basel) ; 12(9)2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35564211

RESUMO

Polyvinyl alcohol (PVA) is a non-toxic biosynthetic polymer. Due to the hydrophilic properties of the PVA, its utilization is an easy tool to modify the properties of materials inducing increased hydrophilicity, which can be noticed in the surface properties of the materials, such as wettability. Based on this motivation, we proposed to obtain high-performance composite materials by a facile synthetic method that involves the cross-linking process of polyvinyl alcohol (PVA) with and aldehyde-functionalized polysulfone(mPSF) precursor, prior to incorporation of modified MWCNTs with hydrophilic groups, thus ensuring a high compatibility between the polymeric and the filler components. Materials prepared in this way have been compared with those based on polyvinyl alcohol and same fillers (mMWCNTs) in order to establish the influence of the polymeric matrix on the composites properties. The amount of mMWCNTs varied in both polymeric matrices between 0.5 and 5 wt%. Fourier transformed infrared with attenuated total reflectance spectroscopy (FTIR-ATR) was employed to confirm the changes noted in the PVA, mPSF and their composites. Hemolysis degree was investigated in correlation with the material structural features. Homogenous distribution of mMWCNTs in all the composite materials has been confirmed by scanning electron microscopy. The hydrophilicity of both composite systems, estimated by the contact angle method, was influenced by the presence of the filler amount mMWCNTs in both matrices (PVA and mPSF). Our work demonstrates that mPSF/mMWCNTs and PVA/mMWCNTs composite could be used as water purification or blood-filtration materials.

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