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1.
PLoS One ; 15(2): e0222371, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32023245

RESUMO

The study of cell aggregation in vitro has a tremendous importance these days. In cancer biology, aggregates and spheroids serve as model systems and are considered as pseudo-tumors that are more realistic than 2D cell cultures. Recently, in the context of brain tumors (gliomas), we developed a new poly(ethylene glycol) (PEG)-based hydrogel, with adhesive properties that can be controlled by the addition of poly(L-lysine) (PLL), and a stiffness close to the brain's. This substrate allows the motion of individual cells and the formation of cell aggregates (within one day), and we showed that on a non-adhesive substrate (PEG without PLL is inert for cells), the aggregates are bigger and less numerous than on an adhesive substrate (with PLL). In this article, we present new experimental results on the follow-up of the formation of aggregates on our hydrogels, from the early stages (individual cells) to the late stages (aggregate compaction), in order to compare, for two cell lines (F98 and U87), the aggregation process on the adhesive and non-adhesive substrates. We first show that a spaceless model of perikinetic aggregation can reproduce the experimental evolution of the number of aggregates, but not of the mean area of the aggregates. We thus develop a minimal off-lattice agent-based model, with a few simple rules reproducing the main processes that are at stack during aggregation. Our spatial model can reproduce very well the experimental temporal evolution of both the number of aggregates and their mean area, on adhesive and non-adhesive soft gels and for the two different cell lines. From the fit of the experimental data, we were able to infer the quantitative values of the speed of motion of each cell line, its rate of proliferation in aggregates and its ability to organize in 3D. We also found qualitative differences between the two cell lines regarding the ability of aggregates to compact. These parameters could be inferred for any cell line, and correlated with clinical properties such as aggressiveness and invasiveness.


Assuntos
Adesão Celular , Agregação Celular , Hidrogéis/química , Modelos Biológicos , Técnicas de Cultura de Células/métodos , Linhagem Celular , Proliferação de Células , Humanos , Cinética , Polietilenoglicóis/química , Polilisina/química
2.
J Agric Food Chem ; 68(4): 1101-1109, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31904947

RESUMO

ε-Poly-l-lysine (ε-PL) consists of 25-35 lysine residues which are linked by an isopeptide bond formed by dehydration condensation of α-carboxyl and ε-amino groups and has good antibacterial activity and broad-spectrum inhibition range. However, there is no clear conclusion about the structure and antibacterial mechanism of ε-PL in aqueous solution. Herein, a high purity of ε-PL was prepared using Amberlite IRC-50 ion-exchange resin. Membrane filtration and dynamic light scattering were used to study the variations of ε-PL aggregation in aqueous solution with pH value. The conformational changes and antibacterial activities of ε-PL and carbamoylated ε-PL in different water environments were studied with circular dichroism (CD) and inhibition zone. The structural changes during the spray-drying process were determined by Fourier transform infrared spectroscopy. The results indicated that the side chain amino charge played a decisive role in the ε-PL conformation and aggregation. ε-PL exhibited the properties of a ß-sheet during spray drying from acidic liquids to solids. The cation enhanced the antibacterial activity of ε-PL but did not play a key role. Instead, the backbone of ε-PL might determine the mechanism of ε-PL antibacterial.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Polilisina/química , Polilisina/farmacologia , Antibacterianos/metabolismo , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/crescimento & desenvolvimento , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Transição de Fase , Polilisina/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Streptomyces/química , Streptomyces/metabolismo
3.
Mater Sci Eng C Mater Biol Appl ; 106: 110251, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753346

RESUMO

In this work, a versatile folic acid (FA) decorated reductive-responsive ε-poly-l-Lysine (ε-PL)-based microcapsules (FA-ε-PLMCs) were designed and facilely assembled by using sonochemical technique. Cellular uptake experiment of FA-ε-PLMCs loaded with Coumarin 6 (C6) as a model of hydrophobic drugs implied that hydrophobic drugs encapsulated inside FA-ε-PLMCs could be delivered selectively into Hela cells via folate-receptor (FR)-mediated endocytosis due to FA decorated on microcapsules. Furthermore, the shells of FA-ε-PLMCs cross-linked by disulfide bonds were derived from sulfhydryl groups (-SH) under ultrasonication. Under reductive environment, the hydrophobic drugs loaded in FA-ε-PLMCs would be easily released due to the cleavage of disulfide bonds. Benefiting from their suitable particle size, good loading capacity for hydrophobic drugs, remarkable targetability and reductive-triggered release, the obtained FA-ε-PLMCs could be a promising hydrophobic drugs carrier for the cancer treatment.


Assuntos
Cápsulas/química , Portadores de Fármacos/química , Ácido Fólico/química , Polilisina/química , Sistemas de Liberação de Medicamentos/métodos , Células HeLa , Humanos , Interações Hidrofóbicas e Hidrofílicas , Estrutura Molecular , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Mater Sci Eng C Mater Biol Appl ; 107: 110212, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761208

RESUMO

A critical challenge to the development of tissue engineering small-diameter vascular grafts is to achieve rapid endothelialization and long-term anticoagulation. It is necessary to graft both adhesion and antithrombus factors onto the surface of polycaprolactone without burst release to promote endothelial cell affinity and antithrombogenicity. A bionic structure with a nanocoating that allows a biologically responsive, long-term release was employed in this work to enable the grafting of various bioactive molecules such as gelatin, polylysine, and heparin. This approach involved orienting the biomimetic vascular structures; the self-assembly grafting of gelatin, polylysine, and heparin nanoparticles; and genipin crosslinking to form a multiphase crosslinked nanocoating. In this biologically inspired design, vascular endothelialization and long-term anticoagulation were successfully induced through a matrix metallopeptidase 2 regulative mechanism by delivering both adhesion and antithrombus factors with a responsive, long-term release without burst release. The method provided a simple and effective approach for delivering dual factors for tissue engineering small-diameter vascular grafts.


Assuntos
Materiais Biomiméticos/química , Nanotecnologia , Materiais Biomiméticos/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Plaquetas/citologia , Prótese Vascular , Adesão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Gelatina/química , Heparina/química , Heparina/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Metaloproteinase 2 da Matriz/química , Metaloproteinase 2 da Matriz/metabolismo , Nanofibras/química , Poliésteres/química , Polilisina/química , Propriedades de Superfície
5.
Carbohydr Polym ; 229: 115484, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31826482

RESUMO

A novel chitosan-based multifunctional nanoparticle (PY-CS-PLA) using cationic polylysine (PL) polymer and L-cysteine has been developed and investigated for the oral delivery of paclitaxel (PTX). As amphiphilic polymer, PY-CS-PLA presented good capability in self-assembling into spherical nanoparticle with mean size of 165 nm, and encapsulating PTX into the hydrophobic core. The encapsulated PTX was observed to be sustainedly released from the functionalized chitosan nanoparticle, and with a positive correlation to the pH value of the medium in the range of 1.2 to 7.4. The in vitro studies indicated that PY-CS-PLA/PTX could effectively enhance the cellular uptake of the PTX in Caco-2 cells. Pharmacokinetic result indicated that the oral bioavailability of PY-CS-PLA/PTX in rats was determined to be 5.63-fold to that of Taxol. Moreover, PY-CS-PLA/PTX improved the distribution of PTX in tumor site and presented better antitumor efficacy in Heps tumor-bearing mice and with less toxicity than other formulations. In conclusion, the PY-CS-PLA/PTX nanoparticle might be developed as a promising delivery vehicle for improving the oral bioavailability and therapeutic effect of hydrophobic antitumor drugs.


Assuntos
Quitosana/química , Cisteína/química , Portadores de Fármacos/química , Nanopartículas/química , Paclitaxel/administração & dosagem , Paclitaxel/química , Polilisina/química , Administração Oral , Animais , Células CACO-2 , Humanos , Camundongos , Paclitaxel/farmacocinética , Paclitaxel/farmacologia , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Nat Struct Mol Biol ; 26(12): 1132-1140, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31768042

RESUMO

Faulty or damaged messenger RNAs are detected by the cell when translating ribosomes stall during elongation and trigger pathways of mRNA decay, nascent protein degradation and ribosome recycling. The most common mRNA defect in eukaryotes is probably inappropriate polyadenylation at near-cognate sites within the coding region. How ribosomes stall selectively when they encounter poly(A) is unclear. Here, we use biochemical and structural approaches in mammalian systems to show that poly-lysine, encoded by poly(A), favors a peptidyl-transfer RNA conformation suboptimal for peptide bond formation. This conformation partially slows elongation, permitting poly(A) mRNA in the ribosome's decoding center to adopt a ribosomal RNA-stabilized single-stranded helix. The reconfigured decoding center clashes with incoming aminoacyl-tRNA, thereby precluding elongation. Thus, coincidence detection of poly-lysine in the exit tunnel and poly(A) in the decoding center allows ribosomes to detect aberrant mRNAs selectively, stall elongation and trigger downstream quality control pathways essential for cellular homeostasis.


Assuntos
Peptídeos/metabolismo , Poli A/metabolismo , Biossíntese de Proteínas , RNA Mensageiro/metabolismo , Ribossomos/metabolismo , Células HEK293 , Humanos , Modelos Moleculares , Conformação de Ácido Nucleico , Peptídeos/química , Poli A/química , Poliadenilação , Polilisina/química , Polilisina/metabolismo , Estabilidade de RNA , RNA Mensageiro/química , RNA de Transferência/química , RNA de Transferência/metabolismo , Aminoacil-RNA de Transferência/química , Aminoacil-RNA de Transferência/metabolismo , Ribossomos/química
7.
ACS Appl Mater Interfaces ; 11(40): 36939-36948, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31513367

RESUMO

Stimuli-responsive biomaterials supply a promising solution to adapt to the complex physiological environment for different biomedical applications. In this study, a dynamic UV-triggered pH-responsive biosurface was constructed on titania nanotubes (TNTs) by loading photoacid generators, diphenyliodonium chloride, into the nanotubes, and grafting 2,3-dimethyl maleic anhydride (DMMA)-modified hyperbranched poly(l-lysine) (HBPLL) onto the surface. The local acidity was dramatically enhanced by UV irradiation for only 30 s, leading to the dissociation of DMMA and thereby the transformation of surface chemistry from negatively charged caboxyl groups to positively charged amino groups. The TNTs-HBPLL-DMMA substrate could better promote proliferation and spreading of rat bone mesenchymal stem cells (rBMSCs) after UV irradiation. The osteogenic differentiation of rBMSCs was enhanced because of the charge reversal in combination with the titania-based substrates.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/efeitos da radiação , Nanotubos/química , Titânio/farmacologia , Raios Ultravioleta , Fosfatase Alcalina/metabolismo , Animais , Compostos de Bifenilo/química , Adesão Celular/efeitos dos fármacos , Adesão Celular/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Masculino , Anidridos Maleicos/síntese química , Anidridos Maleicos/química , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos da radiação , Nanotubos/ultraestrutura , Oniocompostos/química , Polilisina/síntese química , Polilisina/química , Ratos Sprague-Dawley , Propriedades de Superfície
8.
J Mater Sci Mater Med ; 30(9): 102, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31485761

RESUMO

Dysfunction of the corneal endothelium (CE) resulting from progressive cell loss leads to corneal oedema and significant visual impairment. Current treatments rely upon donor allogeneic tissue to replace the damaged CE. A donor cornea shortage necessitates the development of biomaterials, enabling in vitro expansion of corneal endothelial cells (CECs). This study investigated the use of a synthetic peptide hydrogel using poly-ε-lysine (pεK), cross-linked with octanedioic-acid as a potential substrate for CECs expansion and CE grafts. PεK hydrogel properties were optimised to produce a substrate which was thin, transparent, porous and robust. A human corneal endothelial cell line (HCEC-12) attached and grew on pεK hydrogels as confluent monolayers after 7 days, whereas primary porcine CECs (pCECs) detached from the pεK hydrogel. Pre-adsorption of collagen I, collagen IV and fibronectin to the pεK hydrogel increased pCEC adhesion at 24 h and confluent monolayers formed at 7 days. Minimal cell adhesion was observed with pre-adsorbed laminin, chondroitin sulphate or commercial FNC coating mix (fibronectin, collagen and albumin). Functionalisation of the pεK hydrogel with synthetic cell binding peptide H-Gly-Gly-Arg-Gly-Asp-Gly-Gly-OH (RGD) or α2ß1 integrin recognition sequence H-Asp-Gly-Glu-Ala-OH (DGEA) resulted in enhanced pCEC adhesion with the RGD peptide only. pCECs grown in culture at 5 weeks on RGD pεK hydrogels showed zonula occludins 1 staining for tight junctions and expression of sodium-potassium adenosine triphosphase, suggesting a functional CE. These results demonstrate the pεK hydrogel can be tailored through covalent binding of RGD to provide a surface for CEC attachment and growth. Thus, providing a synthetic substrate with a therapeutic application for the expansion of allogenic CECs and replacement of damaged CE.


Assuntos
Proliferação de Células , Transplante de Córnea , Células Endoteliais/fisiologia , Epitélio Posterior/transplante , Hidrogéis/síntese química , Polilisina/química , Tecidos Suporte/química , Animais , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Transplante de Córnea/métodos , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Epitélio Posterior/citologia , Epitélio Posterior/fisiologia , Regeneração Tecidual Guiada/instrumentação , Regeneração Tecidual Guiada/métodos , Humanos , Hidrogéis/química , Hidrogéis/farmacologia , Hidrogéis/uso terapêutico , Teste de Materiais , Polilisina/farmacologia , Suínos
9.
J Microencapsul ; 36(5): 421-431, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31401914

RESUMO

This work describes viability and distribution of INS-1E beta cells in shell-crosslinked alginate capsules, focussing on cells located near the capsule surface. Capsules were formed by air-shearing alginate suspensions of INS-1E cells into a gelling bath, and coating with poly-l-lysine (PLL) and 50% hydrolysed poly(methylvinylether-alt-maleic anhydride) to form crosslinked networks reinforcing the capsule surfaces. The percentage of cells at the capsule surface were determined using 2D and 3D confocal colocalization mapping. Encapsulated INS-1E cells showed high cell viability and progressive cell clustering out to six weeks. About 30% of cells were initially colocated with the 20 micrometer thick alginate-PLL-PMM50 shell, with 7% of cells protruded at the capsule surfaces, both reflecting random cell distributions. Protruding cells may cause cell-based immune responses, weaken capsules, and potentially result in cell escape from the capsules. The data shown indicate that reinforcing capsules with crosslinked shells may assist in preventing cell exposure and escape.


Assuntos
Alginatos/química , Células Imobilizadas/citologia , Reagentes para Ligações Cruzadas/química , Células Secretoras de Insulina/citologia , Polilisina/análogos & derivados , Animais , Cápsulas/química , Linhagem Celular , Extensões da Superfície Celular/ultraestrutura , Sobrevivência Celular , Células Imobilizadas/ultraestrutura , Géis/química , Células Secretoras de Insulina/ultraestrutura , Anidridos Maleicos/química , Polilisina/química , Ratos
10.
J Chromatogr A ; 1608: 460389, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31378528

RESUMO

The integrity of tissue is crucial for a high-quality analysis of matrix-assisted laser desorption ionization-mass spectrometry image (MALDI-MSI). Various embedding media utilized in traditional tissue-sectioning techniques are generally not recommended for MALDI-MSI of dry and fragile plant tissues because of the ion suppression effect in MALDI ionization in the low-mass region as well as the undesirable structural deformation during the sample preparation. In this work, a novel poly-L-lysine (PLL)-based tissue embedding method was developed for MALDI-MSI analysis of dry and fragile aristolochia plant (AP) tissues. The practical application in fixation, embedding, cryosectioning, and mounting of the dry and fragile AP tissues demonstrated that the PLL-based embedding technique could provide good rigidity to the plant tissues analysis compared to that without embedding and gelatin embedding. With the assistance of the PLL embedding medium, high spatial resolution molecular ion maps of main compounds, including aristolochic acids I (AAI) and aristolochic acids II (AAII) in AP root tissue, could be achieved by MALDI-MSI with enhanced signal intensities and no obvious background interference. This work provides an alternative approach for embedding the dry and fragile plant tissues comparable with MALDI-MSI analysis.


Assuntos
Aristolochia/química , Polilisina/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Inclusão do Tecido/métodos , Ácidos Aristolóquicos/análise , Gelatina/química , Manejo de Espécimes
11.
DNA Cell Biol ; 38(10): 1048-1055, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31433200

RESUMO

DNA condensed agents can improve the transfection efficiency of the cationic liposome delivery system. However, various condensed agents have distinct transfection efficiency and cellular cytotoxicity. The object of this study was to screen the optimal agents with the high transfection efficiency and low cytotoxicity from four polymer compressive materials, polyethylenimine (PEI), chitosan, poly-l-lysine (PLL), and spermidine. DNA was precompressed with these four agents and then combined to cationic liposomes. Subsequently, the entrapment and transfection efficiency of the obtained complexes were investigated. Finally, the particle sizes, cytotoxicity, and endocytosis fashion of these copolymers (Lipo-PEI, Lipo-chitosan, Lipo-PLL, and Lipo-spermidine) were examined. It was found that these four copolymers had significantly lower cytotoxicity and higher transfection efficiency (45.5%, 42.4%, 36.8%, and 47.4%, respectively) than those in the control groups. The transfection efficiency of Lipo-PEI and Lipo-spermidine copolymers were better than the other two copolymers. In 293T cells, nystatin significantly inhibited the transfection efficiency of Lipo-PEI-DNA and Lipo-spermidine-DNA (51.88% and 46.05%, respectively), which suggest that the endocytosis pathway of Lipo-spermidine and Lipo-PEI copolymers was probably caveolin dependent. Our study indicated that these dual-degradable copolymers especially liposome-spermidine copolymer could be used as the potential biocompatible gene delivery carriers.


Assuntos
Quitosana/química , Lipossomos/química , Polietilenoimina/química , Polilisina/química , Espermidina/química , Transfecção/métodos , Cátions , Caveolina 1/genética , Caveolina 1/metabolismo , Quitosana/metabolismo , Colesterol/química , Colesterol/metabolismo , Endocitose/efeitos dos fármacos , Endocitose/genética , Ácidos Graxos Monoinsaturados/química , Ácidos Graxos Monoinsaturados/metabolismo , Células HEK293 , Humanos , Lipossomos/metabolismo , Nistatina/farmacologia , Tamanho da Partícula , Plasmídeos/química , Plasmídeos/metabolismo , Polietilenoimina/metabolismo , Polilisina/metabolismo , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/metabolismo , Espermidina/metabolismo
12.
Artif Cells Nanomed Biotechnol ; 47(1): 2391-2404, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31184220

RESUMO

The surface modification of polymeric materials has become critical for improving the bone repair capability of materials. In this study, we used a poly-L-lysine (PLL) coating method to prepare functional poly (lactic acid-glycolic acid) (PLGA) cell microcarriers, and bone morphogenetic protein 7 (BMP-7) and ponericin G1 were immobilized on the surface of microcarriers. The scanning electron microscopy (SEM), water contact angle measurement, and energy-dispersive X-ray spectroscopy (EDX) was used to analyse the surface morphology of PLL-modified PLGA microcarriers (PLL@PLGA) and their ability to promote mineralization. At the same time, the growth factor binding efficiency and antimicrobial activity of the microcarriers were studied. The effects of microcarriers on cell behaviors were evaluated by cultivating MC3T3-E1 cells on different microcarriers. The results showed that the hydrophilicity, protein adsorption, and mineralization induction capability of the microcarriers were significantly improved by PLL surface modification. The biological experiments revealed that BMP-7 and ponericin G1 immobilized-PLL modified microcarriers can effectively inhibit the proliferation of pathogenic microorganisms while enhancing the ability of the microcarriers to promote cell proliferation and osteogenesis differentiation. Therefore, we believe that PLL-modified PLGA cell microcarriers loaded with BMP-7 and ponericin G1 (PLL@PLGA/BMP-7/ponericin G1) have great potential in the field of bone repair.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Osteogênese/efeitos dos fármacos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacologia , Polilisina/química , Células 3T3 , Adsorção , Animais , Proteína Morfogenética Óssea 7/química , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Camundongos , Tecidos Suporte/química
13.
Nanoscale ; 11(24): 11696-11708, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31179463

RESUMO

Peptide-based biomaterials are a promising class of antimicrobial agents that work by physically damaging bacterial cell membranes rather than targeting intracellular factors, resulting in less susceptibility to drug resistance. Herein we report the synthesis of cationic, star-shaped polypeptides with 3 to 8 arms and their evaluation as antimicrobial agents against different types of bacteria. The effects of the arm number and side chain group on their antimicrobial activities were systematically investigated. Compared to their linear counterparts, these star-shaped polypeptides exhibited potent antibacterial activity (which may involve adhesion and disruption processes). The increase of the arm number can efficiently increase the antibacterial activities up until 8 arms, which did not exhibit further improvement of antibacterial activities. Poly(l-lysine) (PLL) modified with an indole group (PLL-g-indo) exhibited the best antibacterial activity among all grafted copolypeptides and improved cytotoxic selectivity towards pathogens over mammalian cells without compromising their hemolytic activities. In vivo studies showed that the star-shaped PLL-g-indo can effectively suppress Enterohaemorrhagic E. coli (EHEC) infection and attenuate the clinical symptoms in mice, suggesting that they are promising antimicrobial agents.


Assuntos
Antibacterianos , Escherichia coli Êntero-Hemorrágica/metabolismo , Síndrome Hemolítico-Urêmica/tratamento farmacológico , Polilisina , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Síndrome Hemolítico-Urêmica/metabolismo , Síndrome Hemolítico-Urêmica/patologia , Camundongos , Polilisina/química , Polilisina/farmacologia
14.
Int J Biol Macromol ; 136: 839-846, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31228501

RESUMO

Antimicrobial bio-nanocomposite films were prepared by incorporating nisin (0.25-0.5% W/W) and ε-polylysine (PL, 0.2% W/W) into corn distarch phosphate/nanocrystalline cellulose based films (CN) via casting method. Nisin and PL had significant effects on color parameters (L*, a*, b* and ∆E*) and improved the mechanical, barrier properties, thermal stability of the films. The CN bio-nanocomposite films incorporation the combination of nisin and PL had synergistic antimicrobial activity against Gram-positive bacteria (S. aureus) and Gram-negative bacteria (E. coli). Structural property assessment by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) revealed that a clear interaction between the hydroxyl groups of corn distarch phosphate and the amino groups of nisin and PL, leading to the microstructure of the CN bio-nanocomposite films with appropriate content of nisin and PL was more continuous and compact. These results indicate that the CN bio-nanocomposite films containing nisin and PL is a potential active packaging material with enhanced physicochemical properties in food industry.


Assuntos
Celulose/química , Fenômenos Mecânicos , Nanocompostos/química , Nisina/química , Polilisina/química , Amido/química , Zea mays/química , Antibacterianos/química , Antibacterianos/farmacologia , Cor , Escherichia coli/efeitos dos fármacos , Embalagem de Alimentos , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície , Temperatura
15.
Adv Mater ; 31(27): e1901828, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31070278

RESUMO

Magnesium (Mg)-based micromotors are combined with live macrophage (MΦ) cells to create a unique MΦ-Mg biohybrid motor system. The resulting biomotors possess rapid propulsion ability stemming from the Mg micromotors and the biological functions provided by the live MΦ cell. To prepare the biohybrid motors, Mg microparticles coated with titanium dioxide and poly(l-lysine) (PLL) layers are incubated with live MΦs at low temperature. The formation of such biohybrid motors depends on the relative size of the MΦs and Mg particles, with the MΦ swallowing up Mg particles smaller than 5 µm. The experimental results and numerical simulations demonstrate that the motion of MΦ-Mg motors is determined by the size of the Mg micromotor core and the position of the MΦ during the attachment process. The MΦ-Mg motors also perform biological functions related to free MΦs such as endotoxin neutralization. Cell membrane staining and toxin neutralization studies confirm that the MΦs maintain their viability and functionality (e.g., endotoxin neutralization) after binding to the Mg micromotors. This new MΦ-Mg motor design can be expanded to different types of living cells to fulfill diverse biological tasks.


Assuntos
Macrófagos/citologia , Magnésio/química , Animais , Linhagem Celular , Membrana Celular/metabolismo , Sobrevivência Celular , Endotoxinas/metabolismo , Camundongos , Microesferas , Polilisina/química , Poliestirenos/química , Titânio/química
16.
Nat Commun ; 10(1): 2223, 2019 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-31110174

RESUMO

Mammalian cells are different from plant and microbial cells, having no exterior cell walls for protection. Environmental assaults can easily damage or destroy mammalian cells. Thus, the ability to develop a biomimetic cell wall (BCW) on their plasma membrane as a shield can advance various applications. Here we demonstrate the synthesis of BCW with a framing template and a crosslinked matrix for shielding live mammalian cells. The framing template is a supramolecular DNA structure. The crosslinked matrix is a polyelectrolyte complex made of alginate and polylysine. As the entire procedure of BCW synthesis is strictly operated under physiological conditions, BCW-covered mammalian cells can maintain high bioactivity. More importantly, the data show that BCW can shield live mammalian cells from not only physical assaults but also biological assaults. Thus, this study has successfully demonstrated the synthesis of BCW on live mammalian cells with great potential of shielding them from environmental assaults.


Assuntos
Materiais Biomiméticos/metabolismo , Parede Celular/metabolismo , DNA/metabolismo , Nanocápsulas/química , Alginatos/química , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Parede Celular/ultraestrutura , Reagentes para Ligações Cruzadas/química , Humanos , Microscopia Eletrônica de Transmissão , Nanocápsulas/ultraestrutura , Polilisina/química
17.
Drug Des Devel Ther ; 13: 1107-1115, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31040647

RESUMO

Background: With the development of drug delivery, novel tools and technological approaches have captured the attention of researchers in recent years. Several target drug delivery systems (DDSs) including nanoparticles (NPs) have been developed as an important strategy to deliver classical medicine. Objective: The objective of this study was to evaluate the application of novel daunorubicin (DNR)-loaded poly(lactic-co-glycolic acid)-poly-l-lysine-polyethylene glycol-transferrin (Tf) nanoparticles (DNR-loaded NPs) in hematologic malignancies in vitro and in vivo. Materials and methods: DNR-loaded NPs were prepared by the modified double-emulsion solvent evaporation/diffusion method, and its microscopic form was observed under scanning electron microscope. Intracellular distribution of DNR was directly detected by fluorescence microscopy. After establishment of a tumor xenograft model by injecting K562 cells into the left leg of nude mice, the therapeutic effect of the DNR-loaded NPs on the growth of tumors was measured by calculating the tumor size, and the relative expression of Caspase-3 protein was detected by immunohistochemical staining. Furthermore, intracellular concentration of DNR and the extent of cell apoptosis in primary leukemia cells were quantified by flow cytometry. Results: DNR-loaded NPs had a spherical shape of about 180 nm in diameter. DNR-loaded NP group showed a significant enhancement of cellular uptake in K562 cells compared with DNR group. Tumor inhibition rate was higher in DNR-loaded NP group in comparison with DNR group, and the relative expression of Caspase-3 protein was upregulated in DNR-loaded NP group compared with DNR group. Furthermore, DNR-loaded NPs obviously increased intracellular concentration of DNR in primary leukemia cells compared with DNR group, but there was no significant difference in primary cell apoptosis between the two groups. These findings suggest that the novel NP DDS can enhance the performance of conventional antitumor drugs and may be suitable for further application in the treatment of hematologic malignancies.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Daunorrubicina/farmacologia , Neoplasias Hematológicas/tratamento farmacológico , Nanopartículas/química , Poliésteres/química , Polilisina/análogos & derivados , Transferrina/química , Animais , Antibióticos Antineoplásicos/química , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Daunorrubicina/química , Ensaios de Seleção de Medicamentos Antitumorais , Neoplasias Hematológicas/patologia , Humanos , Células K562 , Camundongos , Camundongos Nus , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Polilisina/química , Células Tumorais Cultivadas
18.
ACS Appl Mater Interfaces ; 11(22): 19793-19798, 2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31045352

RESUMO

Two-photon lithography allows writing of arbitrary nanoarchitectures in photopolymers. This design flexibility opens almost limitless possibilities for biological studies, but the acrylate-based polymers frequently used do not allow for adhesion and growth of some types of cells. Indeed, we found that lithographically defined structures made from OrmoComp do not support E18 murine cortical neurons. We reacted OrmoComp structures with several diamines, thereby rendering the surfaces directly permissive for neuron attachment and growth by presenting a surface coating similar to the traditional cell biology coating achieved with poly-d-lysine (PDL) and laminin. However, in contrast to PDL-laminin coatings that cover the entire surface, the amine-terminated OrmoComp structures are orthogonally modified in deference to the surrounding glass or plastic substrate, adding yet another design element for advanced biological studies.


Assuntos
Diaminas/química , Animais , Adesão Celular/fisiologia , Técnicas de Cultura de Células , Células Cultivadas , Polilisina/química , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície
19.
Macromol Biosci ; 19(5): e1900036, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30938926

RESUMO

Poly-d-lysine (PDL) and poly-l-lysine are standard surfaces for culturing neural cells; however, both are relatively unstable, costly, and the coated surface typically must be prepared immediately before use. Here, polyelectrolyte multilayers (PEMs) are employed as highly stable, relatively inexpensive, alternative substrates to support primary neural cell culture. Initial findings identify specific silk-based PEMs that significantly outperform the capacity of PDL to promote neuronal survival and process extension. Based on these results, a library of PEM variants, including commercial and bio-sourced polyelectrolytes, is generated and three silk-based PEMs that substantially outperform PDL as a substrate for primary neurons in cell culture are identified. Further, testing these PEM variants as substrates for primary oligodendrocyte progenitors demonstrates that one silk-based PEM functions significantly better than PDL. These findings reveal specificity of cellular responses, indicating that PEMs may be tuned to optimally support different neural cell types.


Assuntos
Proliferação de Células , Matriz Extracelular/química , Neurônios/metabolismo , Polieletrólitos , Polilisina , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Neurônios/citologia , Polieletrólitos/química , Polieletrólitos/farmacologia , Polilisina/química , Polilisina/farmacologia , Ratos , Ratos Sprague-Dawley , Propriedades de Superfície
20.
Sensors (Basel) ; 19(6)2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30934546

RESUMO

Second-generation glucose biosensors are presently the mainstream commercial solution for blood glucose measurement of diabetic patients. Screen-printed carbon electrodes (SPCEs) are the most-used substrate for glucose testing strips. This study adopted hydrophilic and positively charged α-poly-l-lysine (αPLL) as the entrapment matrix for the immobilization of negatively charged glucose oxidase (GOx) and ferricyanide (FIC) on SPCEs to construct a disposable second-generation glucose biosensor. The αPLL modification is shown to facilitate the redox kinetics of FIC and ferrocyanide on the SPCEs. The SPCEs coated with 0.5 mM GOx, 99.5 mM FIC, and 5 mM αPLL had better sensitivity for glucose detection due to the appreciable effect of protonated αPLL on the promotion of electron transfer between GOx and FIC. Moreover, the SPCEs coated with 0.5 mM GOx, 99.5 mM FIC, and 5 mM αPLL were packaged as blood glucose testing strips for the measurement of glucose-containing human serum samples. The glucose testing strips had good linearity from 2.8 mM to 27.5 mM and a detection limit of 2.3 mM. Moreover, the 5 mM αPLL-based glucose testing strips had good long-term stability to maintain GOx activity in aging tests at 50 °C.


Assuntos
Glicemia/análise , Técnicas Eletroquímicas/métodos , Ferricianetos/química , Glucose Oxidase/química , Polilisina/química , Eletrodos , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Glucose Oxidase/metabolismo , Humanos , Limite de Detecção , Oxirredução , Sistemas Automatizados de Assistência Junto ao Leito , Poliaminas/química , Reprodutibilidade dos Testes
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