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This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1007/s11095-020-02971-0.
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Despite recent advances in diagnostic and therapeutic methods in antifungal research, aspergillosis still remains a leading cause of morbidity and mortality. One strategy to address this problem is to enhance the activity spectrum of known antifungals, and we now report the first successful application of Candida antarctica lipase (CAL) for the preparation of optically enriched fluconazole analogues. Anti-Aspergillus activity was observed for an optically enriched derivative, (-)-S-2-(2',4'-difluorophenyl)-1-hexyl-amino-3-(1â´,2â´,4â´)triazol-1â´-yl-propan-2-ol, which exhibits MIC values of 15.6 µg/ml and 7.8 µg/disc in broth microdilution and disc diffusion assays, respectively. This compound is tolerated by mammalian erythrocytes and cell lines (A549 and U87) at concentrations of up to 1,000 µg/ml. When incorporated into dextran nanoparticles, the novel, optically enriched fluconazole analogue exhibited improved antifungal activity against Aspergillus fumigatus (MIC, 1.63 µg/ml). These results not only demonstrate the ability of biocatalytic approaches to yield novel, optically enriched fluconazole derivatives but also suggest that enantiomerically pure fluconazole derivatives, and their nanotized counterparts, exhibiting anti-Aspergillus activity may have reduced toxicity.
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Antifúngicos/farmacologia , Aspergilose/tratamento farmacológico , Aspergillus fumigatus/efeitos dos fármacos , Fluconazol/análogos & derivados , Fluconazol/farmacologia , Células A549 , Linhagem Celular , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Fluconazol/efeitos adversos , Proteínas Fúngicas/metabolismo , Humanos , Lipase/metabolismo , Nanopartículas/químicaRESUMO
A KB cancer cell-selective, liquid crystal microdroplets emulsion is prepared using folic acid-conjugated block copolymers (PS-b-PAA-FA) and sodium dodecyl sulfate (SDS) as a mediator to induce configurational transitions in 4-cyano-4'-pentylbiphenyl (5CB) liquid crystal microdroplets emulsion. The prepared liquid crystal microdroplets emulsion has shown a configurational transition from radial to bipolar on interacting with KB cancer cells, but no transition from radial to bipolar configuration is observed when liquid crystal microdroplets emulsion was allowed to interact with other normal cells such as fibroblast and osteoblast. The KB cancer cell selectivity of liquid crystal microdroplets emulsion has been considered due to the presence of KB cancer cell folate receptor-specific ligand (FA) at the surface of liquid crystal microdroplets, which allowed liquid crystal microdroplets to interact specifically with KB cancer cells. The ligand-receptor interactions have been considered responsible for triggering the configurational transitions from radial to bipolar in liquid crystal microdroplets emulsion. Thus, folate ligand anchored liquid crystal microdroplets emulsion has shown a potential to be used for in vitro detection of KB cancer cells in the early stage of tumor development.
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Ácido Fólico/química , Cristais Líquidos/química , Linhagem Celular , Emulsões/química , HumanosRESUMO
Use of cationic polymers as nonviral gene vectors has several limitations such as low transfection efficiency, high toxicity, and inactivation by serum. In this study, varying amounts of low molecular weight branched polyethylenimine 1.8 kDa (bPEI 1.8) were introduced on to a neutral polymer, poly(vinyl alcohol) (PVA), to bring in cationic charge on the resulting PVA-PEI (PP) nanocomposites. We rationalized that by introducing bPEI 1.8, buffering and condensation properties of the proposed nanocomposites would result in improved gene transfer capability. A series of PVA-PEI (PP) nanocomposites was synthesized using well-established epoxide chemistry and characterized by IR and NMR. Particle size of the PP/DNA complexes ranged between 120 to 135 nm, as determined by dynamic light scattering (DLS), and DNA retardation assay revealed efficient binding capability of PP nanocomposites to negatively charged nucleic acids. In vitro transfection of PP/DNA complexes in HEK293, HeLa, and CHO cells revealed that the best working formulation in the synthesized series, PP-3/DNA complex, displayed ~2-50-fold higher transfection efficiency than bPEIs (1.8 and 25 kDa) and commercial transfection reagents. More importantly, the PP/DNA complexes were stable over a period of time, along with their superior transfection efficiency in the presence of serum compared to serum-free conditions, retaining the nontoxic property of low molecular weight bPEI. The in vivo administration of PP-3/DNA complex in Balb/c mice showed maximum gene expression in their spleen. The study demonstrates the potential of PP nanocomposites as promising nonviral gene vectors for in vivo applications.
Assuntos
DNA , Expressão Gênica , Técnicas de Transferência de Genes , Nanocompostos/química , Polietilenoimina , Álcool de Polivinil , Animais , Células CHO , Cricetinae , Cricetulus , DNA/química , DNA/farmacologia , Vetores Genéticos/química , Vetores Genéticos/farmacologia , Células HEK293 , Células HeLa , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Polietilenoimina/química , Polietilenoimina/farmacologia , Álcool de Polivinil/química , Álcool de Polivinil/farmacologiaRESUMO
Chitosan was partially converted to its chlorohydrin derivative by the reaction with epichlohydrin, which was subsequently reacted with varying amounts of lPEI(2.5 kD) to obtain a series of chitosan-lPEI(2.5 kD) copolymers (CP). These copolymers were then characterized and evaluated in terms of transfection efficiency (in vitro and in vivo), cell viability, DNA release and buffering capacity. The CP-4 copolymer (the best among the CP series) showed enhanced transfection (-2 - 24 folds) in comparison with chitosan, lPEI(2.5 kD), bPEI(25 kD) and Lipofectamine in HEK293, HeLa and CHO cells. The buffering capacity (in the pH range of 3 - 7.5), as shown by confocal microscopy, and DNA-release capability of the CP copolymers, was found to be significantly enhanced over chitosan. Intravenous administration of CP-4/DNA polyplex in mice followed by the reporter gene analysis showed the highest gene expression in spleen. Collectively, these results demonstrate the potential of CP-4 copolymer as a safe and efficient nonviral vector. From the Clinical Editor: Chitosan -PEI (2.5 kD) copolymers (CP) were characterized and their transfection efficiency, DNA release and buffering capacity were studied. The CP-4 copolymer significantly enhanced buffering capacity and provided the highest gene expression levels. The method may be used to enhance DNA transfection.
Assuntos
Quitosana/análogos & derivados , DNA/administração & dosagem , Técnicas de Transferência de Genes , Vetores Genéticos/administração & dosagem , Polietilenoimina/análogos & derivados , RNA Interferente Pequeno/administração & dosagem , Adsorção/efeitos dos fármacos , Animais , Soluções Tampão , Células CHO , Sobrevivência Celular/efeitos dos fármacos , Quitosana/química , Quitosana/toxicidade , Cricetinae , Cricetulus , Endossomos/efeitos dos fármacos , Endossomos/metabolismo , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Células HeLa , Humanos , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Confocal , Tamanho da Partícula , Plasmídeos/metabolismo , Polietilenoimina/química , Polietilenoimina/toxicidade , ATPases Translocadoras de Prótons/antagonistas & inibidores , ATPases Translocadoras de Prótons/metabolismo , Eletricidade Estática , TransfecçãoRESUMO
Linear polyethylenimine (lPEI, 25 kDa) nanoparticles' (LPN) series was synthesized by varying percentage of cross-linking with 1,4-butanediol diglycidyl ether (BDE) and their size, surface charge, morphology, pDNA protection/release, cytotoxicity and transfection efficiency were evaluated. Synthesized nanoparticles (NPs) were spherical in shape (size: â¼109 - 235 nm; zeta potential: +38 to +16 mV). These NPs showed increased buffering capacity with increasing percent cross-linking and also exhibited excellent transfection efficiency (i.e., â¼1.3 - 14.7 folds in case of LPN-5) in comparison with lPEI and the commercial transfection agents used in this study. LPN-5 based GFP-specific siRNA delivery resulted in â¼86% suppression of targeted gene expression. These particles were relatively nontoxic in vitro (in cell lines) and in vivo (in Drosophila). In vivo gene expression studies using LPN-5 in Balb/c mice through intravenous injection showed maximum expression of the reporter gene in the spleen. These results together demonstrate the potential of these particles as efficient transfection reagents. FROM THE CLINICAL EDITOR: The authors demonstrate a novel method of synthesizing linear PEI nanoparticles to utilize these as transfection agents.
Assuntos
Butileno Glicóis/farmacologia , Nanopartículas/efeitos adversos , Polietilenoimina/farmacologia , Transfecção/métodos , Animais , Butileno Glicóis/química , DNA/química , DNA/genética , Drosophila , Portadores de Fármacos , Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Nanopartículas/uso terapêutico , Polietilenoimina/química , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismoRESUMO
Histidine-rich peptides are commonly used in recombinant protein production as purification tags, allowing the one-step affinity separation of the His-tagged proteins from the extracellular media or cell extracts. Genetic engineering makes feasible the post-purification His-tag removal by inserting, between the tag and the main protein body, a target site for trans-acting proteases or a self-proteolytic peptide with regulatable activities. However, for technical ease, His tags are often not removed and the fusion proteins eventually used in this form. In this commentary, we revise the powerful biological properties of histidine-rich peptides as endosomolytic agents and as architectonic tags in nanoparticle formation, for which they are exploited in drug delivery and other nanomedical applications. These activities, generally unknown to biotechnologists, can unwillingly modulate the functionality and biotechnological performance of recombinant proteins in which they remain trivially attached.
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Biotecnologia/métodos , Histidina/química , Nanomedicina/métodos , Peptídeos/química , Sequência de Aminoácidos , Histidina/metabolismo , Humanos , Dados de Sequência Molecular , Peptídeos/metabolismo , Engenharia de Proteínas/métodosRESUMO
Amphotericin B (AmB) exhibits potential antileishmanial activity, with only a little rate of recurrence. However, low bioavailability and severe nephrotoxicity are among the major shortcomings of AmB-based therapy. Various AmB nanoformulations have been developed, which to an extent, have reduced its toxicity and increased the drug efficacy. To further reduce the nonspecific tissue distribution and the cost of the treatment, the current AmB-based formulations require additional improvements. Combination of natural bioenhancers with AmB is expected to further increase its bioavailability. Therefore, we developed a nanoformulation of AmB and piperine (Pip), a plant alkaloid, known to enhance the bioavailability of various drugs, by entrapping them in guar gum, a macrophage targeting polymer. Owing to the ease of oral delivery, these nanoparticles (NPs) were coated with eudragit to make them suitable for oral administration. The formulated eudragit-coated AmB and Pip-loaded NPs (Eu-HDGG-AmB-Pip-NPs) exhibited controlled release of the loaded therapeutic agents and protected the drug from acidic pH. These NPs exhibited effective suppression of growth of both promastigotes and amastigotes of Leishmania donovani parasite under in vitro. In vivo evaluation of these NPs for therapeutic efficacy in golden hamster-L. donovani model demonstrated enhanced drug bioavailability, non-nephrotoxic nature, and potential antileishmanial activity with up to 96% inhibition of the parasite. Graphical abstract.
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Alcaloides , Leishmaniose Visceral , Nanopartículas , Anfotericina B/farmacologia , Animais , Benzodioxóis , Cricetinae , Portadores de Fármacos/uso terapêutico , Galactanos , Leishmaniose Visceral/tratamento farmacológico , Mananas , Piperidinas , Gomas Vegetais , Alcamidas Poli-InsaturadasRESUMO
We demonstrate a large energy output and a wider output spectral bandwidth from Nd:glass-based regenerative amplifiers. The maximum energy extracted from the regenerative amplifier is 24 mJ with an overall gain of 3.4 x 10(8). The maximum output bandwidth achieved is 4.2 nm FWHM when the input pulse spectral bandwidth is 7 nm FWHM. This was made possible by a new cavity optimization technique.
RESUMO
Galactomannan (GM), a natural polymer, is recognized to specifically target macrophage mannose receptors (CD206). Interestingly, some reports indicate that GM has an ability to induce pro-inflammatory (M1-like, tumericidal) polarization in macrophages, suggesting its potential use as an anti-cancer agent. Hydrazinocurcumin (HC), a pyrazole derivative of curcumin, is reported to possess increased anti-cancer efficacy over curcumin. Moreover, HC-encapsulated nanoparticles (NPs) have been reported to re-polarize tumor-associated macrophages (TAMs) from anti-inflammatory (M2-like, tumor-promoting) to pro-inflammatory phenotype. To club the therapeutic properties of both GM and HC, we synthesized self-assembled amphiphilic PEGylated GM NPs loaded with HC (PSGM-HCNPs) and evaluated their potential to re-polarize TAMs towards M1-like phenotype. PSGM-HCNPs re-polarized IL-4 polarized RAW 264.7 cells via a phenotypic switch from M2- to M1-like by elevating ROS level, decreasing CD206 and arginase-1 expressions and increasing pro-inflammatory cytokines' secretion. Conditioned medium (CM) taken from re-polarized RAW 264.7 cells containing residual PSGM-HCNPs elevated ROS, arrested cell cycle, and induced apoptosis in 4T1, breast cancer cells, and Ehrlich's ascites carcinoma (EAC) cells. Decreased levels of MMP-2, MMP-9, and Bcl-2 with increased levels of Bax in both 4T1 and EAC cells indicated anti-metastatic and apoptosis-inducing potential of the CM. Treatment of PSGM-HCNPs in EAC-bearing mice reduced tumor burden, increased their survival time, decreased CD206+F4/80+ cells, and increased TNF-α+F4/80+ cells signifying decrease in M2- and increase in M1-like skewness among ascitic TAMs.
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Antineoplásicos/administração & dosagem , Carcinoma de Ehrlich/tratamento farmacológico , Curcumina/análogos & derivados , Hidrazinas/administração & dosagem , Macrófagos/efeitos dos fármacos , Mananas/administração & dosagem , Nanopartículas/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Carcinoma de Ehrlich/imunologia , Carcinoma de Ehrlich/patologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Curcumina/administração & dosagem , Citocinas/imunologia , Sinergismo Farmacológico , Feminino , Galactose/análogos & derivados , Macrófagos/imunologia , Camundongos , Polietilenoglicóis/administração & dosagemRESUMO
Evanescent-field-coupled (EFC) waveguide-mode sensors can be used to detect nucleic acids or proteins from the changes in the local index of refraction upon adsorption of the target molecule on a waveguide surface. We recently described an EFC waveguide-mode sensor in which nanometric holes on a waveguide film resulted in an improved sensitivity in the analysis of the interactions of biomolecules. In the present study, we have shown that sensitivity depends upon the diameter of the holes, where increase in diameter of holes increases spectral shift resulting in an improved sensitivity. Using this improved EFC waveguide-mode sensor, we could detect interactions between RNA and a small ligand, cyanocobalamin (vitamin B 12), and between RNA and a protein (human coagulation factor IXa). These two interactions were monitored on surfaces modified with biotin-streptavidin-biotin and N-(2-trifluoroethanesulfonatoethyl)- N-(methyl)triethoxysilylpropyl-3-amine, respectively.
Assuntos
Aptâmeros de Nucleotídeos/análise , Aptâmeros de Nucleotídeos/metabolismo , Técnicas Biossensoriais/métodos , Nanotecnologia/métodos , Biotina/metabolismo , Ligantes , Nanotecnologia/instrumentação , Ligação Proteica , Sensibilidade e Especificidade , Coloração e Rotulagem , Estreptavidina/metabolismoRESUMO
We have explored the potential of cell factory-derived bioactive molecules, isolated from conditioned media of primary goat chondrocytes, for the repair of subchondral cartilage defects. Enzyme-linked immunosorbent assay (ELISA) confirms the presence of transforming growth factor-ß1 in an isolated protein fraction (12.56 ± 1.15 ng/mg protein fraction). These bioactive molecules were used alone or with chitosan-agarose-gelatin cryogel scaffolds, with and without chondrocytes, to check whether combined approaches further enhance cartilage repair. To evaluate this, an in vivo study was conducted on New Zealand rabbits in which a subchondral defect (4.5 mm wide × 4.5 mm deep) was surgically created. Starting after the operation, bioactive molecules were injected at the defect site at regular intervals of 14 days. Histopathological analysis showed that rabbits treated with bioactive molecules alone had cartilage regeneration after 4 weeks. However, rabbits treated with bioactive molecules along with scaffolds, with or without cells, showed cartilage formation after 3 weeks; 6 weeks after surgery, the cartilage regenerated in rabbits treated with either bioactive molecules alone or in combinations showed morphological similarities to native cartilage. No systemic cytotoxicity or inflammatory response was induced by any of the treatments. Further, ELISA was done to determine systemic toxicity, which showed no difference in concentration of tumour necrosis factor-α in blood serum, before or after surgery. In conclusion, intra-articular injection with bioactive molecules alone may be used for the repair of subchondral cartilage defects, and bioactive molecules along with chondrocyte-seeded scaffolds further enhance the repair. Copyright © 2015 John Wiley & Sons, Ltd.
Assuntos
Cartilagem , Técnicas de Cultura de Células/métodos , Condrócitos/metabolismo , Criogéis/química , Alicerces Teciduais/química , Animais , Cartilagem/lesões , Cartilagem/metabolismo , Cartilagem/patologia , Quitosana/química , Meios de Cultivo Condicionados/química , Meios de Cultivo Condicionados/farmacologia , Feminino , Gelatina/química , Cabras , Coelhos , Sefarose/químicaRESUMO
Two cross-linkers based on polyethylene glycol (PEG) (MW=6 and 8 kDa), were synthesized for self-assembling and formation of nanoparticles of branched, high molecular weight polyethylenimine (PEI). Cross-linking was realized in two ways, viz., ionic as well as covalent. Ionic cross-linking was accomplished by using PEG-bis (phosphate) whereas, the covalent one was achieved by using PEG-bis (p-nitrophenylcarbonate). A range of nanoparticles of PEI was prepared by varying the degree of cross-linking (i.e. the amount of cross-linkers used). PEI-PEG nanoparticles were characterized by dynamic light scattering and transmission electron microscopy and found to be in the range of approximately 18-75 nm (hydrodynamic radii) with almost uniform population. Subsequently, these particles were used for DNA binding assay and zeta-potential measurements, taking native PEI-PEG nanoparticles as reference. As expected, the zeta potential values decreased, on increasing the percentage of cross-linking as well as on complexation with DNA. Further, PEI-PEG nanoparticles were investigated for their transfecting efficacy on COS-1 cells. It was found that PEI-PEG nanoparticles were 5- to 16-fold more efficient as transfecting agents compared to lipofectin and PEI itself. The toxicity of PEI-PEG nanoparticles was found to be reduced considerably in comparison to PEI polymer, as determined by MTT colorimetric assay. Out of the various systems prepared, PEI-PEG8000 (5% ionic) nanoparticles were found to be the most efficient transfecting agent for in vitro transfection.
Assuntos
Nanoestruturas , Polietilenoimina/química , Transfecção/métodos , Animais , Células COS , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Chlorocebus aethiops , Reagentes de Ligações Cruzadas , DNA/administração & dosagem , DNA/química , Eletroquímica , Eritrócitos/efeitos dos fármacos , Excipientes , Hemólise/efeitos dos fármacos , Humanos , Microscopia Eletrônica de Transmissão , Peso Molecular , Tamanho da Partícula , Fosfatos/química , Polietilenoglicóis/químicaRESUMO
The main aim of the current study is to compare the physicochemical properties, cytotoxicity and gene-transfer ability of electrostatically and covalently linked nanocomposites of polyethylenimine (PEI) and polyacrylic acid (PAA) on mammalian cells. Two series of nanocomposites, ionic PEI-PAA (iPP) and covalent PEI-PAA (cPP), were synthesized by varying the amounts of polyacrylic acid (PAA). Physicochemical characterization revealed that iPP nanopcomposites were of bigger sized than cPP nanocomposites with zeta potential almost comparable. Nucleic acid binding assay displayed that iPP and cPP nanocomposites, having sufficient cationic charge, efficiently interacted with plasmid DNA and completely retarded its electrophoretic mobility on agarose gel. In vitro MTT assay showed slightly higher cell viability of cPP/pDNA complexes over their ionic counterparts. Both the series of nanocomposite/pDNA complexes exhibited considerably higher transfection efficacy compared to pDNA complexes of native bPEI and the standard transfection reagent, Lipofectamine, with cPP/pDNA complexes performed much better than iPP/pDNA complexes. Flow cytometry further confirmed these findings where cPP-4/pDNA complex showed transfection in â¼ 85% HEK293 cells, while iPP-2/pDNA complex transfected â¼ 67% HEK293 cells. Lipofectamine/pDNA and bPEI/pDNA complexes could transfect just â¼ 35% and â¼ 26% HEK293 cells. All these results demonstrate the superiority of covalently linked nanocomposites (cPP) which could be used as efficient carriers for nucleic acids in future gene delivery applications.
Assuntos
Resinas Acrílicas/química , Nanocompostos/química , Plasmídeos/genética , Polietilenoimina/química , Animais , Células CHO , Sobrevivência Celular/genética , Cricetulus , DNA/química , DNA/genética , Técnicas de Transferência de Genes , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Microscopia de Fluorescência , Estrutura Molecular , Tamanho da Partícula , Plasmídeos/química , Espectrometria de Fluorescência , Transfecção/métodosRESUMO
In this study, the potential of cryogel bilayer wound dressing and skin regenerating graft for the treatment of surgically created full thickness wounds was evaluated. The top layer was composed of polyvinylpyrrolidone-iodine (PVP-I) cryogel and served as the antiseptic layer, while the bottom regenerative layer was made using gelatin cryogel. Both components of the bilayer showed typical features of a cryogel interconnected macropore network, rapid swelling, high water uptake capacity of about 90%. Both PVP and gelatin cryogel showed high tensile strength of 45 and 10 kPa, respectively. Gelatin cryogel sheets were essentially elastic and could be stretched without any visible deformation. The antiseptic PVP-I layer cryogel sheet showed sustained iodine release and suppressed microbial growth when tested with skin pathogens (zone of inhibition â¼2 cm for sheet of 0.9 cm diameter). The gelatin cryogel sheet degraded in vitro in weeks. The gelatin cryogel sheet supported cell infiltration, attachment, and proliferation of fibroblasts and keratinocytes. Microparticles loaded with bioactive molecules (mannose-6-phosphate and human fibrinogen) were also incorporated in the gelatin cryogel sheets for their role in enhancing skin regeneration and scar free wound healing. In vivo evaluation of healing capacity of the bilayer cryogel was checked in rabbits by creating full thickness wound defect (diameter 2 cm). Macroscopic and microscopic observation at regular time intervals for 4 weeks demonstrated better and faster skin regeneration in the wound treated with cryogel bilayer as compared to untreated defect and the repair was comparable to commercial skin regeneration scaffold Neuskin-F. Complete skin regeneration was observed after 4 weeks of implantation with no sign of inflammatory response. Defects implanted with cryogel having mannose-6-phosphate showed no scar formation, while the wound treated with bilayer incorporated with human fibrinogen microparticles showed early signs of skin regeneration; epidermis formation occurred at 2 weeks after implantation.
Assuntos
Criogéis/farmacologia , Transplante de Pele , Cicatrização/efeitos dos fármacos , Animais , Criogéis/química , Gelatina/química , Humanos , Coelhos , Regeneração/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/lesõesRESUMO
UNLABELLED: Polyethylenimines (PEIs) are considered as the most promising vectors for non-viral gene delivery applications. Here, we report the synthesis and in vitro evaluation of two non-toxic and biodegradable polymers, TEPA@bPEI (TBP) and TEPA@lPEI (TLP), derived from low molecular weight branched and linear polyethylenimines by the stepwise reactions with methylacrylate (aza-Michael reaction) and amidation with tetraethylenepentamine (TEPA). These polymers not only showed their ability to bind and condense pDNA into nano-sized complexes but also provided protection against nucleases in cellular milieu. Both the polymers exhibited excellent buffering capacity and efficiently delivered nucleic acids (plasmid DNA and siRNA) across the mammalian cells (CHO and A549 cells) and outclassed native polymers and the commercial transfection reagents in terms of transfection efficiency and target gene silencing, and that too without compromising on biocompatibility i.e. TOXICITY: The results advocate the promising potential of the PEI derivatives as safe and potent nucleic acid carriers for practical gene delivery applications.
Assuntos
Materiais Biocompatíveis , DNA/genética , Polietilenoimina/química , RNA Interferente Pequeno/genética , Transfecção , Animais , Células CHO , Linhagem Celular Tumoral , Cricetinae , Cricetulus , Humanos , Microscopia Eletrônica de TransmissãoRESUMO
In our previous report [Kumar, P.; Dhawan, G.; Chandra, R.; Gupta, K.C. Polyamine-assisted rapid and clean cleavage of oligonucleotides from cis-diol bearing universal support. Nucl. Acids Res. 2002, 30, e130 (1-8)], we demonstrated polyamine-mediated deprotection of oligonucleotides from cis-diol group bearing universal polymer support (I). However, vulnerability of the conventional dC(bz) to modifications under these conditions compelled us to employ dC(ac) during synthesis of oligonucleotide using conventional synthons. Here, a new set of simple and rapid deprotection conditions has been developed for the complete cleavage of oligonucleotides from the 1,4-anhydroerythritol-based universal polymer support employing conventional dC(bz) synthon. Using manganese-imidazole complex in aqueous ammonium hydroxide (â¼ 30%), fully deprotected oligonucleotide sequences were obtained in 40 min, which were analyzed on reverse phase-HPLC and compared with the standard oligomers in terms of their retention time. Finally, their biological compatibility was established by analyzing PCR amplified products of npsA gene of N. meningitidis.
Assuntos
Eritritol/análogos & derivados , Oligonucleotídeos/síntese química , Polímeros/química , Hidróxido de Amônia , Cromatografia Líquida de Alta Pressão , Eritritol/química , Hidrólise , Oligonucleotídeos/química , Poliaminas/químicaRESUMO
Conventional cancer chemotherapy leads to severe side effects, which limits its use. Nanoparticles (NPs) based delivery systems offer an effective alternative. Several evidences highlight the importance of Bromelain (BL), a proteolytic enzyme, as an anti-tumor agent which however has been limited due to the requirement of high doses at the tumor site. Therefore, we illustrate the development of BL loaded poly (lactic-co-glycolic acid) NPs that show enhanced anti-tumor effects compared to free BL. The formulated NPs with a mean particle size of 130.4 ± 8.81 nm exhibited sustained release of BL. Subsequent investigation revealed enhanced anti-tumor ability of NPs in 2-stage skin tumorigenesis mice model. Reduction in average number of tumors (â¼ 2.3 folds), delay in tumorigenesis (â¼ 2 weeks), percent tumorigenesis (â¼ 4 folds), and percent mortality rate as well as a reduction in the average tumor volume (â¼ 2.5 folds) in mice as compared to free BL were observed. The NPs were found to be superior in exerting chemopreventive effects over chemotherapeutic effects at 10 fold reduced dose than free BL, validated by the enhanced ability of NPs (â¼ 1.8 folds) to protect the DNA from induced damage. The effects were also supported by histopathological evaluations. NPs were also capable of modulating the expression of pro-apoptotic (P53, Bax) and anti-apoptotic (Bcl2) proteins. Therefore, our findings demonstrate that developed NPs formulation could be used to improve the efficacy of chemotherapy by exerting chemo-preventive effects against induced carcinogenesis at lower dosages.
Assuntos
Anticarcinógenos/administração & dosagem , Bromelaínas/administração & dosagem , Carcinogênese/efeitos dos fármacos , Portadores de Fármacos/administração & dosagem , Nanopartículas/química , Proteínas de Plantas/administração & dosagem , Neoplasias Cutâneas/prevenção & controle , Administração Cutânea , Ananas/química , Animais , Anticarcinógenos/química , Anticarcinógenos/uso terapêutico , Bromelaínas/química , Bromelaínas/uso terapêutico , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/química , Preparações de Ação Retardada/uso terapêutico , Portadores de Fármacos/química , Portadores de Fármacos/uso terapêutico , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Estabilidade Enzimática , Ácido Láctico/química , Masculino , Camundongos , Nanopartículas/ultraestrutura , Tamanho da Partícula , Proteínas de Plantas/química , Proteínas de Plantas/uso terapêutico , Caules de Planta/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Distribuição Aleatória , Pele/efeitos dos fármacos , Pele/patologia , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/patologia , Análise de Sobrevida , Carga Tumoral/efeitos dos fármacosRESUMO
Liquid crystal (LC) microdroplets have been prepared for visual detection of HepG2 cells using 4-cyano-4'-pentyl biphenyl molecules in the presence of sodium dodecyl sulfate as a mediator and ß-galactose-conjugated poly(styrene-b-acrylic acid) block copolymer (PS-b-PA-G) as a modifier of LC-water interfaces. To clarify the effect of ß-galactose-containing ligands on the orientational transitions of LC microdroplets, maltotriose as a ligand simulant was conjugated to poly(styrene-b-acrylic acid) and used as a LC modifier. The interaction of HepG2 cells with the ß-galactose-conjugated block copolymer was effective in causing orientational transitions, from radial to bipolar, in LC microdroplets, whereas interactions of HepG2 cells with maltotriose-conjugated block copolymers were ineffective in inducing orientational transitions in LC microdroplets. To confirm the necessity of the PS segment of the block copolymer for transmitting the ligand-receptor interaction forces from the interface to the core of the LC microdroplets, ß-galactose-conjugated block copolymers (PS-b-PA-G) and homopolymers (PVLA) were synthesized and used to prepare LC microdroplets. The LC microdroplets containing a ß-galactose-conjugated homopolymer did not show orientational transitions upon contact with HepG2 cells. However, LC microdroplets containing a ß-galactose-conjugated block copolymer showed orientational transitions from radial to bipolar, indicating that the polystyrene segment in the amphiphilic block copolymer is essential for the effective transmission of ligand-receptor interactions to the core of LC microdroplets. ß-Galactose anchored LC microdroplets were able to detect 1.0 ± 0.1 HepG2 cells per µm2 of the test cell and had shown significantly high reproducibility (p < 0.05, n = 3). The configurational transition in LC microdroplets that was dependent on ligand-receptor interactions was used to develop a LC microdroplet-based biosensor for the detection of HepG2 cells in biological fluids.