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1.
J Mater Chem B ; 12(12): 3047-3062, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38421173

RESUMO

Many efforts have been devoted to bone tissue to regenerate damaged tissues, and the development of new biocompatible materials that match the biological, mechanical, and chemical features required for this application is crucial. Herein, a collagen-decorated scaffold was prepared via electrospinning using a synthesized unsaturated copolyester (poly(globalide-co-pentadecalactone)), followed by two coupling reactions: thiol-ene functionalization with cysteine and further conjugation via EDC/NHS chemistry with collagen, aiming to design a bone tissue regeneration device with improved hydrophilicity and cell viability. Comonomer ratios were varied, affecting the copolymer's thermal and chemical properties and highlighting the tunable features of this copolyester. Functionalization with cysteine created new carboxyl and amine groups needed for bioconjugation with collagen, which is responsible for providing biological and structural integrity to the extra-cellular matrix. Bioconjugation with collagen turned the scaffold highly hydrophilic, decreasing its contact angle from 107 ± 2° to 0°, decreasing the copolymer crystallinity by 71%, and improving cell viability by 85% compared with the raw scaffold, thus promoting cell growth and proliferation. The highly efficient and biosafe strategy to conjugate polymers and proteins created a promising device for bone repair in tissue engineering.


Assuntos
Cisteína , Alicerces Teciduais , Alicerces Teciduais/química , Colágeno/química , Osso e Ossos , Regeneração Óssea , Polímeros
2.
Pharmaceutics ; 15(3)2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36986860

RESUMO

Superparamagnetic iron oxide nanoparticles (SPIONs) have their use approved for the diagnosis/treatment of malignant tumors and can be metabolized by the organism. To prevent embolism caused by these nanoparticles, they need to be coated with biocompatible and non-cytotoxic materials. Here, we synthesized an unsaturated and biocompatible copolyester, poly (globalide-co-ε-caprolactone) (PGlCL), and modified it with the amino acid cysteine (Cys) via a thiol-ene reaction (PGlCLCys). The Cys-modified copolymer presented reduced crystallinity and increased hydrophilicity in comparison to PGlCL, thus being used for the coating of SPIONS (SPION@PGlCLCys). Additionally, cysteine pendant groups at the particle's surface allowed the direct conjugation of (bio)molecules that establish specific interactions with tumor cells (MDA-MB 231). The conjugation of either folic acid (FA) or the anti-cancer drug methotrexate (MTX) was carried out directly on the amine groups of cysteine molecules present in the SPION@PGlCLCys surface (SPION@PGlCLCys_FA and SPION@PGlCLCys_MTX) by carbodiimide-mediated coupling, leading to the formation of amide bonds, with conjugation efficiencies of 62% for FA and 60% for MTX. Then, the release of MTX from the nanoparticle surface was evaluated using a protease at 37 °C in phosphate buffer pH~5.3. It was found that 45% of MTX conjugated to the SPIONs were released after 72 h. Cell viability was measured by MTT assay, and after 72 h, 25% reduction in cell viability of tumor cells was observed. Thus, after a successful conjugation and subsequent triggered release of MTX, we understand that SPION@PGlCLCys has a strong potential to be treated as a model nanoplatform for the development of treatments and diagnosis techniques (or theranostic applications) that can be less aggressive to patients.

3.
Adv Colloid Interface Sci ; 303: 102645, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35358807

RESUMO

Devastating plant diseases and soil depletion rationalize an extensive use of agrochemicals to secure the food production worldwide. The sustained release of fertilizers and pesticides in agriculture is a promising solution to the eco-toxicological impacts and it might reduce the amount and increase the effectiveness of agrochemicals administration in the field. This review article focusses on carriers with diameters below 1 µm, such as capsules, spheres, tubes and micelles that promote the sustained release of actives. Biopolymer nanocarriers represent a potentially environmentally friendly alternative due to their renewable origin and biodegradability, which prevents the formation of microplastics. The social aspects, economic potential, and success of commercialization of biopolymer based nanocarriers are influenced by the controversial nature of nanotechnology and depend on the use case. Nanotechnology's enormous innovative power is only able to unfold its potential to limit the effects of climate change and to counteract current environmental developments if the perceived risks are understood and mitigated.


Assuntos
Agroquímicos , Plásticos , Agroquímicos/farmacologia , Biopolímeros , Preparações de Ação Retardada , Horticultura , Ciências Sociais
4.
J Biomed Mater Res B Appl Biomater ; 110(3): 702-711, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34619018

RESUMO

Poly(thioether-ester) (PTEe) nanoparticles obtained by thiol-ene polymerization have received attention of many researchers due to several advantages, including, biocompatibility and biodegradability. The search for new nanomaterials requires toxicity studies to assess potential toxic effects of their administration. Therefore, the aim of this study was to evaluate the in vivo acute toxicity of PTEe and poly(thioether-ester)-coated magnetic nanoparticles prepared by thiol-ene polymerization in miniemulsion. These nanoparticles presented a mean size of approximately 120 nm, spherical morphology, and negative surface charge. Doses of 40 mg/kg were administered intraperitoneally to Swiss mice and nociceptive, behavioral and biochemical parameters were investigated in five different organs. None of the nanoparticles led to any alterations in the nociceptive and behavioral responses. Biochemical alterations were observed in liver, decreasing the sulfhydryl and glutathione (GSH) levels, suggesting the dependence of the GSH metabolism in the elimination of the nanoparticles. In general, both nanoparticle types did not cause disturbances in biochemical parameters analyzed in others organs. These results suggest that both nanoparticle types did not induce acute toxicity to the different organs evaluated, reinforcing the biocompatibility of PTEe nanoparticles synthetized by thiol-ene polymerization.


Assuntos
Nanopartículas , Sulfetos , Animais , Ésteres , Nanopartículas Magnéticas de Óxido de Ferro , Camundongos , Nanopartículas/toxicidade , Polimerização , Compostos de Sulfidrila , Sulfetos/toxicidade
5.
Adv Colloid Interface Sci ; 300: 102582, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34953375

RESUMO

Nanoparticles have emerged as promising drug delivery systems for the treatment of several diseases. Novel cancer therapies have exploited these particles as alternative adjuvant therapies to overcome the traditional limitations of radio and chemotherapy. Curcumin is a natural bioactive compound found in turmeric, that has been reported to show anticancer activity against several types of tumors. Despite some biological limitations regarding its absorption in the human body, curcumin encapsulation in poly(lactic-co-glycolic acid) (PLGA), a non-toxic, biodegradable and biocompatible polymer, represents an effective strategy to deliver a drug to a tumor site. Furthermore, PLGA nanoparticles can be engineered with targeting moieties to reach specific cancer cells, thus enhancing the antitumor effects of curcumin. We herein aim to bring an up-to-date summary of the recently developed strategies for curcumin delivery to different types of cancer cells through encapsulation in PLGA nanoparticles, correlating their effects with those of curcumin on the biological capabilities acquired by cancer cells (cancer hallmarks). We discuss the targeting strategies proposed for advanced curcumin delivery and the respective improvements achieved for each cancer cell analyzed, in addition to exploring the encapsulation techniques employed. The conjugation of correct encapsulation techniques with tumor-oriented targeting design can result in curcumin-loaded PLGA nanoparticles that can successfully integrate the elaborate network of development of alternative cancer treatments along with traditional ones. Finally, the current challenges and future demands to launch these nanoparticles in oncology are comprehensively examined.


Assuntos
Curcumina , Nanopartículas , Neoplasias , Curcumina/farmacologia , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Humanos , Neoplasias/tratamento farmacológico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros
6.
J Colloid Interface Sci ; 601: 678-688, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34091315

RESUMO

The current spraying of agrochemicals is unselective and ineffective, consuming a high amount of fungicides, which endangers the environment and human health. Cellulose-based nanocarriers (NCs) are a promising tool in sustainable agriculture and suitable vehicles for stimuli-responsive release of agrochemicals to target cellulase-segregating fungi, which cause severe plant diseases such as Apple Canker. Herein, cellulose was modified with undec-10-enoic acid to a hydrophobic and cross-linkable derivative, from which NCs were prepared via thiol-ene addition in miniemulsion. During the crosslinking reaction, the NCs were loaded in situ with hydrophobic fungicides, Captan and Pyraclostrobin. NCs with average sizes ranging from 200 to 300 nm and an agrochemical-load of 20 wt% were obtained. Cellulose-degrading fungi, e.g. Neonectria. ditissima which is responsible for Apple Canker, lead to the release of fungicides from the aqueous NC dispersions suppressing fungal growth. In contrast, the non-cellulase segregating fungi, e.g. Cylindrocladium buxicola, do not degrade the agrochemical-loaded NCs. This selective action against Apple Canker fungi, N. ditissima, proves the efficacy of NC-mediated drug delivery triggered by degradation in the exclusive presence of cellulolytic fungi. Cellulose NCs represent a sustainable alternative to the current unselective spraying of agrochemicals that treats many crop diseases ineffectively.


Assuntos
Agroquímicos , Hypocreales , Celulose , Humanos , Doenças das Plantas
7.
J Nanosci Nanotechnol ; 21(11): 5493-5498, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33980359

RESUMO

Nanomaterials, such as magnetic nanoparticles have attracted significant attention of medical area due to their capacity to improve the performance of immunoassays. Therefore the aim of this work was to study the bovine serum albumin (BSA) conjugation in superparamagnetic (MNPs)/poly(methyl methacrylate) (PMMA) nanoparticles with further characterization and application in enzyme-linked immunosorbent (ELISA) assay. The successful conjugation of BSA in MNPs- PMMA nanoparticles was confirmed by several techniques, including light scattering, zeta potential, transmission electron microscopy (TEM) and Lowry protein quantification assay. The superparamagnetic properties were confirmed by vibrating sample magnetometer. BSA conjugated MNPs-PMMA nanoparticles presented higher interactions with antibody than free BSA. The BSA + MNPs-PMMA nanoparticles (magnetic ELISA assay) reduced the time and increased the sensibility of traditional ELISA assay, reinforcing the idea that the use these nanomaterials are an excellent alternative for the immunoassays field.


Assuntos
Nanopartículas , Soroalbumina Bovina , Ensaio de Imunoadsorção Enzimática , Nanopartículas Magnéticas de Óxido de Ferro , Fenômenos Magnéticos , Polimetil Metacrilato
8.
Mater Sci Eng C Mater Biol Appl ; 120: 111651, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33545819

RESUMO

The use of nanoparticles as drug delivery systems to simultaneously carry several therapeutic agents is an attractive idea to create new synergic treatments and to develop the next generation of cancer therapies. Therefore, the goal of this study was the simultaneous encapsulation of a hydrophilic drug, sodium diethyldithiocarbamate (DETC), and a hydrophobic drug, 4-nitrochalcone (4NC), in beeswax nanoparticles (BNs) to evaluate the in vitro synergic activity of this combination against melanoma (B16F10) cells. BNs were prepared by water/oil/water double emulsion in the absence of organic solvents. Transmission electron microscopy imaging and dynamic light scattering analyses indicated the formation of BNs with a semispherical shape, average diameter below 250 nm, relatively narrow distributions, and negative zeta potential. The double emulsion technique proved to be effective for the simultaneous encapsulation of DETC and 4NC with efficiencies of 86.2% and 98.7%, respectively, and this encapsulation did not affect the physicochemical properties of the BNs. DETC and 4NC loaded in BNs exhibited a higher cytotoxicity toward B16F10 cells than free 4NC and DETC. This simultaneous encapsulation led to a synergic effect of DETC and 4NC on B16F10 cells, decreasing the cell viability from 46% (DETC BNs) and 54% (4NC BNs) to 64% (DETC+4NC BNs). Therefore, the IC50 of DETC+4NC was also lower than that of either when individually encapsulated, and that of free DETC or 4NC. Therefore, DETC and 4NC were efficiently simultaneously encapsulated in BNs and this drug combination was able to generate an in vitro synergic therapeutic effect on B16F10 cells.


Assuntos
Melanoma , Nanopartículas , Ditiocarb , Portadores de Fármacos , Humanos , Tamanho da Partícula , Ceras
9.
ACS Appl Bio Mater ; 4(2): 1552-1562, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35014505

RESUMO

Poly(ε-caprolactone) (PCL) is commonly used in devices for tissue reconstruction due to its biocompatibility and suitable mechanical properties. However, its high crystallinity and hydrophobicity do not favor cell adhesion and difficult polymer bioresorption. To improve these characteristics, the development of engineered scaffolds for tissue regeneration, based on poly(globalide-co-ε-caprolactone) (PGlCL) covalently bonded with N-acetylcysteine (PGlCL-NAC) was proposed. The scaffolds were obtained from polymer blends of PCL and PGlCL-NAC, using the electrospinning technique. The use of PGlCL-NAC allowed for the modification of the physical and chemical properties of PCL electrospun scaffolds, including an expressive reduction in the fiber's diameter, hydrophobicity, and crystallinity. All electrospun scaffolds showed no cytotoxicity against fibroblasts (McCoy cells). In vitro biocompatibility assays showed that all tested scaffolds provided high cell viability and proliferation in short-term (NRU, MTT, and nuclear morphology assays) and long-term (clonogenic assay) assays. Nevertheless, PGlCL-NAC based scaffolds have favored the survival and proliferation of the cells in comparison to PCL scaffolds. Cell adhesion on the scaffolds assessed by electronic microscopy images confirmed this behavior. These results suggest that the incorporation of PGlCL-NAC in scaffolds for tissue regeneration could be a promising strategy to improve cell-surface interactions and contribute to the development of more efficiently engineered biomedical devices.


Assuntos
Acetilcisteína/química , Caproatos/metabolismo , Fibroblastos/metabolismo , Lactonas/metabolismo , Poliésteres/química , Engenharia Tecidual/métodos
10.
Colloids Surf B Biointerfaces ; 197: 111434, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33166932

RESUMO

There has been considerable interest in the development of novel photosensitisers for photodynamic therapy (PDT). The use of liposomes as drug delivery systems containing simultaneously two or more drugs is an attractive idea to create a new platform for PDT application. Therefore, the aim of this study was to evaluate the synergistic effect of diethyldithiocarbamate (DETC) and zinc phthalocyanine (PDT) co-encapsulated in liposomes. The reverse-phase evaporation method resulted in the successful encapsulation of DETC and ZnPc in liposomes, with encapsulation efficiencies above 85 %, mean size of 308 nm, and zeta potential of - 36 mV. The co-encapsulation decreased the cytotoxic effects in mouse embryo fibroblast (NIH3T3) cells and inhibited damage to human erythrocytes compared to free DETC + ZnPc. In addition, both the free drugs and co-encapsulated ones promoted more pronounced phototoxic effects on human breast cancer cells (MDA-MB231) compared to treatment with ZnPc alone. This synergistic effect was determined by DETC-induced decreases in the antioxidant enzyme activity of superoxide dismutase (SOD) and glutathione (GSH).


Assuntos
Neoplasias da Mama , Compostos Organometálicos , Fotoquimioterapia , Animais , Ditiocarb/farmacologia , Feminino , Humanos , Indóis , Isoindóis , Lipossomos , Camundongos , Células NIH 3T3 , Compostos Organometálicos/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Compostos de Zinco
11.
J Drug Target ; 28(10): 1110-1123, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32546016

RESUMO

The use of compounds from natural or synthetic sources and nanotechnology may represent an alternative to develop new drugs for the leishmaniasis treatment. DETC is an inhibitor of the SOD1 enzyme, which leads to increased ROS production, important for the elimination of Leishmania. Thus, our objective was to assess the leishmanicidal in vitro effect of free Diethydithiocarbamate (DETC) and DETC loaded in beeswax-copaiba oil nanoparticles (DETC-Beeswax-CO Nps) on L. amazonensis forms and elucidate the possible mechanisms involved in the parasite death. DETC-Beeswax-CO Nps presented size below 200 nm, spherical morphology, negative zeta potential, and high encapsulation efficiency. Free DETC reduced the viability of promastigotes and increase ROS production, lower the mitochondrial membrane potential, cause phosphatidylserine exposure, and enhance plasma membrane permeability, in addition to promoting morphological changes in the parasite. Free DETC proved toxic in the assessment of toxicity to murine macrophages, however, the encapsulation of this compound was able to reduce these toxic effects on macrophages. DETC-Beeswax-CO Nps exerted anti-amastigote effect by enhancing the production of ROS, superoxide anion, TNF-α, IL-6, and reduced IL-10 in macrophages. Therefore, free DETC induces antipromastigote effect by apoptosis-like; and DETC-Beeswax-CO Nps exerted anti-leishmanial effect due to pro-oxidant and pro-inflammatory response.


Assuntos
Ditiocarb/farmacologia , Leishmania/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Nanopartículas/química , Espécies Reativas de Oxigênio/metabolismo , Animais , Apoptose/efeitos dos fármacos , Ditiocarb/administração & dosagem , Camundongos Endogâmicos BALB C , Preparações de Plantas/química , Propriedades de Superfície , Ceras/química
12.
J Biomater Sci Polym Ed ; 31(15): 1895-1911, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32552460

RESUMO

The combination of hyperthermia and chemotherapy has a potential synergic effect in antitumor activity. The development of new biocompatible and biodegradable polymers to simultaneously encapsulate magnetic nanoparticles (MNPs) and antitumoral drugs offer new cancer treatment opportunities. Here, biodegradable and biocompatible poly(thioether-ester) (PTEe) was used to encapsulate MNPs and 4-nitrochalcone (4NC) using miniemulsification and solvent evaporation. The resulting hybrid particles (MNPs-4NC-PTEe) had nanometer-scale diameters, spherical morphology, negative surface charge, high encapsulation efficiency, and superparamagnetic properties. Results showed that 4NC release occurred through diffusion. Free 4NC and MNPs + 4NC-PTEe did not have any cytotoxic effect on erythrocytes and mouse embryonic fibroblast (NIH3T3) cells. 4NC antitumor activity was verified on human cervical cancer (HeLa) and melanoma (B16F10) cells. Cellular uptake of MNPs + 4NC-PTEe nanoparticles was higher in HeLa cells compared to B16F10 and NIH3T3 cells. The hyperthermia application (115 kHz-500 Oe) potentiated the 4NC effects on HeLa and B16F10 cells when MNPs + 4NC-PTEe nanoparticles were used, indicating more effective antitumor activity. We concluded that the use of MNPs + 4NC-PTEe nanoparticles associated with hyperthermia is a promising form of treatment for some types of cancers.


Assuntos
Hipertermia Induzida , Nanopartículas de Magnetita , Nanopartículas , Animais , Ésteres , Fibroblastos , Células HeLa , Humanos , Hipertermia , Camundongos , Células NIH 3T3 , Sulfetos
13.
Bioprocess Biosyst Eng ; 43(7): 1279-1286, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32189054

RESUMO

In this work, the free lipase Eversa® Transform 2.0 was used as a catalyst for enzymatic glycerolysis reaction in a solvent-free system. The product was evaluated by nuclear magnetic resonance (1H NMR) and showed high conversion related to hydroxyl groups. In sequence, the product of the glycerolysis was used as stabilizer and biopolyol for the synthesis of poly(urea-urethane) nanoparticles (PUU NPs) aqueous dispersion by the miniemulsion polymerization technique, without the use of a further surfactant in the system. Reactions resulted in stable dispersions of PUU NPs with an average diameter of 190 nm. After, the formation of the PUU NPs in the presence of concentrated lipase Eversa® Transform 2.0 was studied, aiming the lipase immobilization on the NP surface, and a stable enzymatic derivative with diameters around 231 nm was obtained. The hydrolytic enzymatic activity was determined using ρ-nitrophenyl palmitate (ρ-NPP) and the immobilization was confirmed by morphological analysis using transmission electron microscopy and fluorescence microscopy.


Assuntos
Enzimas Imobilizadas/imunologia , Glicerol/química , Lipase/metabolismo , Polímeros/química , Poliuretanos/química , Microscopia Eletrônica de Transmissão , Sonicação , Espectroscopia de Infravermelho com Transformada de Fourier
14.
Polymers (Basel) ; 11(11)2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31689927

RESUMO

Crosslinking of an unsaturated aliphatic polyester poly(globalide) (PGl) by bistriazolinediones (bisTADs) is reported. First, a monofunctional model compound, phenyl-TAD (PTAD), was tested for PGl functionalisation. 1H-NMR showed that PTAD-ene reaction was highly efficient with conversions up to 97%. Subsequently, hexamethylene bisTAD (HM-bisTAD) and methylene diphenyl bisTAD (MDP-bisTAD) were used to crosslink electrospun PGl fibres via one- and two-step approaches. In the one-step approach, PGl fibres were collected in a bisTAD solution for in situ crosslinking, which resulted in incomplete crosslinking. In the two-step approach, a light crosslinking of fibres was first achieved in a PGl non-solvent. Subsequent incubation in a fibre swelling bisTAD solution resulted in fully amorphous crosslinked fibres. SEM analysis revealed that the fibres' morphology was uncompromised by the crosslinking. A significant increase of tensile strength from 0.3 ± 0.08 MPa to 2.7 ± 0.8 MPa and 3.9 ± 0.5 MPa was observed when PGI fibres were crosslinked by HM-bisTAD and MDP-bisTAD, respectively. The reported methodology allows the design of electrospun fibres from biocompatible polyesters and the modulation of their mechanical and thermal properties. It also opens future opportunities for drug delivery applications by selected drug loading.

15.
Bioprocess Biosyst Eng ; 42(10): 1625-1634, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31267175

RESUMO

In this work, a fed-batch approach was adopted to overcome propionic acid lipase inactivation effects in the benzyl propionate direct esterification mediated by lipases. The ester synthesis was performed using commercial immobilized (Novozym 435) and lyophilized form Candida antarctica fraction B lipase (Cal B) as biocatalysts of the esterification between benzyl alcohol and propionic acid in a solvent-free system. The reaction involved the propionic acid-controlled addition during the first 5 h ensuring an excess of alcohol to dilute the media. The biocatalyst Novozym 435 showed a good performance in the first cycle of the fed-batch esterification, ensuring 90 and 99% of conversion at substrates molar ratio of 1:1 and 1:5 (acid:alcohol), respectively. However, the enzyme lost the activity and the conversions were sharply reduced at the second cycle. A novel qualitative protein content analysis by optical microscopy showed that the lipase was desorbed from the support after the esterification, and this behavior was strongly related to the presence of propionic acid in the reaction medium. The lyophilized Cal B was also tested as biocatalyst of the benzyl propionate esterification and showed a similar performance (related to the Novozym 435) in ester conversion and initial reaction rates for all substrates molar ratios tested. Since the substrates affected the performance of the Novozym 435, the lyophilized Cal B is the most suitable catalyst to the benzyl propionate esterification with conversions above 90%, considering a the fed-batch approach in a solvent-free system.


Assuntos
Biocatálise , Enzimas Imobilizadas/química , Proteínas Fúngicas/química , Lipase/química , Propionatos/síntese química , Esterificação
16.
Appl Biochem Biotechnol ; 189(3): 745-759, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31111376

RESUMO

The total or partial substitution of fossil raw materials by biobased materials from renewable resources is one of the great challenges of our society. In this context, the reaction under mild condition as enzyme-catalyzed esterification was applied to investigate the esterification of the biobased 10-undecenoic acid with 2-hydroxyethyl methacrylate (HEMA) to obtain a new diene ester monomer. The environmentally friendly enzymatic reaction presented up to 100% of conversion; moreover, the production of possible by-products was minimized controlling reaction time and amount of enzyme. Furthermore, the presence of chloroform was evaluated during the enzymatic reactions and despite high conversions with higher enzyme concentration, the solvent-free system showed fast kinetics even with 1.13 U/g substrates. In addition, the commercial immobilized lipases Novozym 435 and NS 88011 could be applied for up to 10 cycles keeping conversions about 90%. The scale-up of the reaction was possible and a purification procedure was applied in order to isolate the diene ester monomer 2-(10-undecenoyloxy)ethyl methacrylate, preserving its double bonds, which could allow a potential use of this product in the synthesis of new renewable polymers through techniques as metathesis, thiol-ene, or free-radical polymerization.


Assuntos
Ésteres/química , Ésteres/síntese química , Proteínas Fúngicas/metabolismo , Lipase/metabolismo , Ácidos Undecilênicos/química , Biocatálise , Técnicas de Química Sintética , Esterificação , Química Verde , Cinética , Metacrilatos/química
17.
Colloids Surf B Biointerfaces ; 176: 507-512, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30711703

RESUMO

Leishmaniasis is considered a neglected tropical disease that represents a Public Health problem due to its high incidence. In the search of new alternatives for Leishmaniasis treatment diethyldithiocarbamate (DETC) has shown an excellent leishmanicidal activity and the incorporation into drug carrier systems, such as solid lipid nanoparticles (SLNs), is very promising. In the present work DETC loaded in beeswax nanoparticles containing copaiba oil were obtained by the double emulsion/melt technique. The nanoparticles were characterized and leishmanicidal activity against L. amazonensis promastigotes forms and cytotoxicity in murine macrophages were evaluated. SLNs presented size below 200 nm, spherical morphology, negative charge surface, high encapsulation efficiency, above 80%, and excellent stability. Moreover, Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) analyses were performed to evaluate the chemical structure and possible interactions between DETC and SLNs. SLNs provided a protection for DETC, decreasing its cytotoxic effects in macrophages, which led to an improvement in the selectivity against the parasites, which almost doubled from free DETC (11.4) to DETC incorporated in SLNs (18.2). These results demonstrated that SLNs had a direct effect on L. amazonensis promastigotes without affect the viability of macrophage cell, can be a promising alternative therapy for the cutaneous treatment of L. amazonensis.


Assuntos
Ditiocarb/farmacologia , Emulsões/química , Fabaceae/química , Leishmania/efeitos dos fármacos , Nanopartículas/química , Óleos de Plantas/farmacologia , Ceras/farmacologia , Animais , Varredura Diferencial de Calorimetria , Morte Celular/efeitos dos fármacos , Lipídeos/química , Camundongos Endogâmicos BALB C , Nanopartículas/ultraestrutura , Tamanho da Partícula , Solventes , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática
18.
Pharm Dev Technol ; 24(5): 593-599, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30457422

RESUMO

The current paucity of effective and affordable drugs for the treatment of leishmaniasis renders the search for new therapeutic alternatives a priority. Gallic acid-related compounds display anti-parasitic activities and their incorporation into drug carrier systems, such as polymeric nanoparticles may be a viable alternative for leishmaniasis treatment. Therefore, this study focused on the synthesis and characterization of octyl gallate (G8) loaded poly(methyl methacrylate) (PMMA) nanoparticles via miniemulsion polymerization in order to increase the leishmanicidal activity of this compound. G8 loaded PMMA nanoparticles presented a spherical morphology with a mean size of 108 nm, a negatively charged surface (-33 ± 5 mV) and high encapsulation efficiency (83% ± 5). Fourier-transform infrared spectroscopy and X-ray diffraction analysis confirmed that G8 was encapsulated in PMMA nanoparticles and presented a biphasic release profile. The G8 loaded PMMA nanoparticles did not present cytotoxic effect on human red blood cells. G8 loaded PMMA nanoparticles displayed a leishmanicidal activity almost three times higher than free G8 while the cytotoxic activity against human THP-1 cells remained unchanged.


Assuntos
Portadores de Fármacos/química , Ácido Gálico/análogos & derivados , Leishmania/efeitos dos fármacos , Polimetil Metacrilato/química , Tripanossomicidas/administração & dosagem , Tripanossomicidas/farmacologia , Células CACO-2 , Linhagem Celular , Liberação Controlada de Fármacos , Emulsões/química , Ácido Gálico/administração & dosagem , Ácido Gálico/química , Ácido Gálico/farmacologia , Hemólise/efeitos dos fármacos , Humanos , Leishmaniose/tratamento farmacológico , Nanopartículas/química , Nanopartículas/ultraestrutura , Tripanossomicidas/química
19.
Bioprocess Biosyst Eng ; 42(2): 213-222, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30367249

RESUMO

The use of green sources for materials synthesis has gained popularity in recent years. This work investigated the immobilization of lipase NS-40116 (Thermomyces lanuginosus lipase) in polyurethane foam (PUF) using a biopolyol obtained through the enzymatic glycerolysis between castor oil and glycerol, catalyzed by the commercial lipase Novozym 435 for the PUF formation. The reaction was performed to obtain biopolyol resulting in the conversion of 64% in mono- and diacylglycerol, promoting the efficient use of the reaction product as biopolyol to obtain polyurethane foam. The enzymatic derivative with immobilized lipase NS-40116 presented apparent density of 0.19 ± 0.03 g/cm3 and an immobilization yield was 94 ± 4%. Free and immobilized lipase NS-40116 were characterized in different solvents (methanol, ethanol, and propanol), temperatures (20, 40, 60 and 80 °C), pH (3, 5, 7, 9 and 11) and presence of ions Na+, Mg++, and Ca++. The support provided higher stability to the enzyme, mainly when subjected to acid pH (free lipase lost 80% of relative activity after 360 h of contact, when the enzymatic derivative lost around 22%) and high-temperature free lipase lost 50% of relative activity, while the immobilized remained 95%. The enzymatic derivative was also used for esterification reactions and conversions around 66% in fatty acid methyl esters, using abdominal chicken fat as feedstock, were obtained in the first use, maintaining this high conversion until the fourth reuse, proving that the support obtained using environmentally friendly techniques is applicable.


Assuntos
Enzimas Imobilizadas/química , Glicerol/química , Química Verde/métodos , Lipase/química , Polímeros/química , Poliuretanos/síntese química , Biocatálise , Biotecnologia/métodos , Microbiologia Ambiental , Esterificação , Proteínas Fúngicas , Cinética , Poliuretanos/química , Solventes , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
20.
Bioprocess Biosyst Eng ; 41(5): 585-591, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29350294

RESUMO

Benzyl propionate is an aromatic ester that possesses a fruity odor and is usually found in nature in the composition of some fruits such as plums and melons. This work aimed for the benzyl propionate synthesis by esterification using a new immobilized enzyme preparation with low-cost material from Candida antarctica (NS 88011) and three commercial immobilized lipases (Novozym 435, Lipozyme TL-IM and Lipozyme RM-IM). Novozym 435 had the best performance even when the solvent tert-butanol was absent of the reaction medium. Results from a 22 factorial design showed that an increase in the enzyme amount led to a higher conversion, even when the temperature was kept at the low value. Currently, no research had synthesized successfully benzyl propionate via esterification mediated by lipases; and we reached an ester conversion of ~ 44% after 24 h indicating that it is a promising route for benzyl propionate biotechnological production.


Assuntos
Candida/enzimologia , Enzimas Imobilizadas/química , Ésteres/síntese química , Proteínas Fúngicas/química , Lipase/química , Biocatálise , Ésteres/química
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