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1.
Mikrochim Acta ; 191(6): 332, 2024 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-38748375

RESUMO

Nifedipine (NIF), as one of the dihydropyridine calcium channel blockers, is widely used in the treatment of hypertension. However, misuse or ingestion of NIF can result in serious health issues such as myocardial infarction, arrhythmia, stroke, and even death. It is essential to design a reliable and sensitive detection method to monitor NIF. In this work, an innovative molecularly imprinted polymer dual-emission fluorescent sensor (CDs@PDA-MIPs) strategy was successfully designed for sensitive detection of NIF. The fluorescent intensity of the probe decreased with increasing NIF concentration, showing a satisfactory linear relationship within the range 1.0 × 10-6 M ~ 5.0 × 10-3 M. The LOD of NIF was 9.38 × 10-7 M (S/N = 3) in fluorescence detection. The application of the CDs@PDA-MIPs in actual samples such as urine and Qiangli Dingxuan tablets has been verified, with recovery ranging from 97.8 to 102.8% for NIF. Therefore, the fluorescent probe demonstrates great potential as a sensing system for detecting NIF.


Assuntos
Carbono , Dopamina , Corantes Fluorescentes , Limite de Detecção , Polímeros Molecularmente Impressos , Nifedipino , Pontos Quânticos , Espectrometria de Fluorescência , Pontos Quânticos/química , Nifedipino/química , Nifedipino/análise , Corantes Fluorescentes/química , Polímeros Molecularmente Impressos/química , Dopamina/urina , Dopamina/análise , Carbono/química , Espectrometria de Fluorescência/métodos , Humanos , Polimerização , Impressão Molecular , Comprimidos/análise
2.
J Am Chem Soc ; 146(19): 13598-13606, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38691811

RESUMO

Nucleic acid-binding dyes (NuABDs) are fluorogenic probes that light up after binding to nucleic acids. Taking advantage of their fluorogenicity, NuABDs have been widely utilized in the fields of nanotechnology and biotechnology for diagnostic and analytical applications. We demonstrate the potential of NuABDs together with an appropriate nucleic acid scaffold as an intriguing photocatalyst for precisely controlled atom-transfer radical polymerization (ATRP). Additionally, we systematically investigated the thermodynamic and electrochemical properties of the dyes, providing insights into the mechanism that drives the photopolymerization. The versatility of the NuABD-based platform was also demonstrated through successful polymerizations using several NuABDs in conjunction with diverse nucleic acid scaffolds, such as G-quadruplex DNA or DNA nanoflowers. This study not only extends the horizons of controlled photopolymerization but also broadens opportunities for nucleic acid-based materials and technologies, including nucleic acid-polymer biohybrids and stimuli-responsive ATRP platforms.


Assuntos
Corantes Fluorescentes , Processos Fotoquímicos , Polimerização , Catálise , Corantes Fluorescentes/química , Radicais Livres/química , DNA/química , Ácidos Nucleicos/química , Quadruplex G
3.
Cell Stem Cell ; 31(5): 640-656.e8, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38701758

RESUMO

Post-implantation, the pluripotent epiblast in a human embryo forms a central lumen, paving the way for gastrulation. Osmotic pressure gradients are considered the drivers of lumen expansion across development, but their role in human epiblasts is unknown. Here, we study lumenogenesis in a pluripotent-stem-cell-based epiblast model using engineered hydrogels. We find that leaky junctions prevent osmotic pressure gradients in early epiblasts and, instead, forces from apical actin polymerization drive lumen expansion. Once the lumen reaches a radius of ∼12 µm, tight junctions mature, and osmotic pressure gradients develop to drive further growth. Computational modeling indicates that apical actin polymerization into a stiff network mediates initial lumen expansion and predicts a transition to pressure-driven growth in larger epiblasts to avoid buckling. Human epiblasts show transcriptional signatures consistent with these mechanisms. Thus, actin polymerization drives lumen expansion in the human epiblast and may serve as a general mechanism of early lumenogenesis.


Assuntos
Actinas , Camadas Germinativas , Pressão Osmótica , Polimerização , Humanos , Actinas/metabolismo , Camadas Germinativas/metabolismo , Camadas Germinativas/citologia , Modelos Biológicos , Junções Íntimas/metabolismo
4.
Biomacromolecules ; 25(5): 2925-2933, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38691827

RESUMO

A "one-step" strategy has been demonstrated for the tunable synthesis of multifunctional aliphatic polycarbonates (APCs) with ethylene oxide (EO), ethylene carbonate (EC), and cyclohexene oxide (CHO) side groups by the copolymerization of 4-vinyl-1-cyclohexene diepoxide with carbon dioxide under an aminotriphenolate iron/PPNBz (PPN = bis(triphenylphosphine)-iminium, Bz = benzoate) binary catalyst. By adjusting the PPNBz-to-iron complex ratio and incorporating auxiliary solvents, the content of functional side groups can be tuned within the ranges of 53-75% for EO, 18-47% for EC, and <1-7% for CHO. The yield and molecular weight distribution of the resulting multifunctional APCs are affected by the viscosity of the polymerization system. The use of tetrahydrofuran as an auxiliary solvent enables the preparation of narrow-distribution polycarbonates at high conversion. This work presents a novel perspective for the preparation of tailorable multifunctional APCs.


Assuntos
Dióxido de Carbono , Cimento de Policarboxilato , Polimerização , Dióxido de Carbono/química , Cimento de Policarboxilato/química , Compostos de Epóxi/química , Óxido de Etileno/química , Cicloexenos/química , Catálise , Viscosidade , Dioxolanos
5.
Biomacromolecules ; 25(5): 3122-3130, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38696355

RESUMO

Synthesis of polysaccharide-b-polypeptide block copolymers represents an attractive goal because of their promising potential in delivery applications. Inspired by recent breakthroughs in N-carboxyanhydride (NCA) ring-opening polymerization (ROP), we present an efficient approach for preparation of a dextran-based macroinitiator and the subsequent synthesis of dextran-b-polypeptides via NCA ROP. This is an original approach to creating and employing a native polysaccharide macroinitiator for block copolymer synthesis. In this strategy, regioselective (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) oxidation of the sole primary alcohol located at the C-6 position of the monosaccharide at the nonreducing end of linear dextran results in a carboxylic acid. This motif is then transformed into a tetraalkylammonium carboxylate, thereby generating the dextran macroinitiator. This macroinitiator initiates a wide range of NCA monomers and produces dextran-b-polypeptides with a degree of polymerization (DP) of the polypeptide up to 70 in a controlled manner (D < 1.3). This strategy offers several distinct advantages, including preservation of the original dextran backbone structure, relatively rapid polymerization, and moisture tolerance. The dextran-b-polypeptides exhibit interesting self-assembly behavior. Their nanostructures have been investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM), and adjustment of the structure of block copolymers allows self-assembly of spherical micelles and worm-like micelles with varied diameters and aspect ratios, revealing a range of diameters from 60 to 160 nm. Moreover, these nanostructures exhibit diverse morphologies, including spherical micelles and worm-like micelles, enabling delivery applications.


Assuntos
Dextranos , Peptídeos , Polimerização , Dextranos/química , Peptídeos/química , Peptídeos/síntese química , Polímeros/química , Polímeros/síntese química , Óxidos N-Cíclicos/química , Anidridos/química , Polissacarídeos/química , Micelas
6.
Biomacromolecules ; 25(5): 2990-3000, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38696732

RESUMO

Recently, we reported the synthesis of a hydrophilic aldehyde-functional methacrylic polymer (Angew. Chem., 2021, 60, 12032-12037). Herein we demonstrate that such polymers can be reacted with arginine in aqueous solution to produce arginine-functional methacrylic polymers without recourse to protecting group chemistry. Careful control of the solution pH is essential to ensure regioselective imine bond formation; subsequent reductive amination leads to a hydrolytically stable amide linkage. This new protocol was used to prepare a series of arginine-functionalized diblock copolymer nanoparticles of varying size via polymerization-induced self-assembly in aqueous media. Adsorption of these cationic nanoparticles onto silica was monitored using a quartz crystal microbalance. Strong electrostatic adsorption occurred at pH 7 (Γ = 14.7 mg m-2), whereas much weaker adsorption occurred at pH 3 (Γ = 1.9 mg m-2). These findings were corroborated by electron microscopy, which indicated a surface coverage of 42% at pH 7 but only 5% at pH 3.


Assuntos
Arginina , Nanopartículas , Nanopartículas/química , Adsorção , Arginina/química , Concentração de Íons de Hidrogênio , Polimerização , Dióxido de Silício/química , Polímeros/química , Ácidos Polimetacrílicos/química , Ácidos Polimetacrílicos/síntese química
7.
Biomacromolecules ; 25(5): 2792-2802, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38602263

RESUMO

Polyesters from furandicarboxylic acid derivatives, i.e., dimethyl 2,5-furandicarboxylate (2,5-DMFDCA) and 2,4-DMFDCA, show interesting properties among bio-based polymers. Another potential heteroaromatic monomer, 3,4-bis(hydroxymethyl)furan (3,4-BHMF), is often overlooked but holds promise for biopolymer synthesis. Cleaning and greening synthetic procedures, i.e., enzymatic polymerization, offer sustainable pathways. This study explores the Candida antarctica lipase B (CALB)-catalyzed copolymerization of 3,4-BHMF with furan dicarboxylate isomers and aliphatic diols. The furanic copolyesters (co-FPEs) with higher polymerization degrees are obtained using 2,4-isomer, indicating CALB's preference. Material analysis revealed semicrystalline properties in all synthesized 2,5-FDCA-based co-FPEs, with multiple melting temperatures (Tm) from 53 to 124 °C and a glass-transition temperature (Tg) of 9-10 °C. 2,4-FDCA-based co-FPEs showed multiple Tm from 43 to 61 °C and Tg of -14 to 12 °C; one of them was amorphous. In addition, all co-FPEs showed a two-step decomposition profile, indicating aliphatic and semiaromatic segments in the polymer chains.


Assuntos
Ácidos Dicarboxílicos , Proteínas Fúngicas , Furanos , Lipase , Poliésteres , Polimerização , Lipase/química , Lipase/metabolismo , Furanos/química , Proteínas Fúngicas/química , Ácidos Dicarboxílicos/química , Poliésteres/química , Poliésteres/síntese química , Isomerismo , Basidiomycota
8.
Biomacromolecules ; 25(5): 3018-3032, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38648261

RESUMO

Different cellulose nanocrystal (CNC) forms (dried vs never-dried) can lead to different degrees of CNC reassembly, the formation of nanofibril-like structures, in nanocomposite latex-based pressure-sensitive adhesive (PSA) formulations. CNC reassembly is also affected by CNC sonication and loading as well as the protocol used for CNC addition to the polymerization. In this study, carboxylated CNCs (cCNCs) were incorporated into a seeded, semibatch, 2-ethylhexyl acrylate/methyl methacrylate/styrene emulsion polymerization and cast as pressure-sensitive adhesive (PSA) films. The addition of CNCs led to a simultaneous increase in tack strength, peel strength, and shear adhesion, avoiding the typical trade-off between the adhesive and cohesive strength. Increased CNC reassembly resulted from the use of dried, redispersed, and sonicated cCNCs, along with increased cCNC loading and addition of the cCNCs at the seed stage of the polymerization. The increased degree of CNC reassembly was shown to significantly increase the shear adhesion by enhancing the elastic modulus of the PSA films.


Assuntos
Adesivos , Celulose , Látex , Nanopartículas , Celulose/química , Adesivos/química , Nanopartículas/química , Látex/química , Polimerização , Nanocompostos/química , Pressão
9.
Biomacromolecules ; 25(5): 3033-3043, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38652289

RESUMO

Intrinsically disordered proteins (IDPs) do not have a well-defined folded structure but instead behave as extended polymer chains in solution. Many IDPs are rich in glycine residues, which create steric barriers to secondary structuring and protein folding. Inspired by this feature, we have studied how the introduction of glycine residues influences the secondary structure of a model polypeptide, poly(l-glutamic acid), a helical polymer. For this purpose, we carried out ring-opening copolymerization with γ-benzyl-l-glutamate and glycine N-carboxyanhydride (NCA) monomers. We aimed to control the glycine distribution within PBLG by adjusting the reactivity ratios of the two NCAs using different reaction conditions (temperature, solvent). The relationship between those conditions, the monomer distributions, and the secondary structure enabled the design of intrinsically disordered polypeptides when a highly gradient microstructure was achieved in DMSO.


Assuntos
Anidridos , Glicina , Proteínas Intrinsicamente Desordenadas , Polimerização , Glicina/química , Proteínas Intrinsicamente Desordenadas/química , Anidridos/química , Ácido Poliglutâmico/química , Ácido Poliglutâmico/análogos & derivados , Estrutura Secundária de Proteína , Peptídeos/química , Dobramento de Proteína
10.
J Hazard Mater ; 471: 134313, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38669927

RESUMO

Secondary lignification of the root exodermis of Kandelia obovata is crucial for its response to adversity such as high salinity and anaerobic environment, and this lignification is also effective in blocking cadmium transport to the roots. However, how the differences in lignification of root exodermis at different developmental stages respond to Cd stress and its regulatory mechanisms have not been revealed. In this study, after analyzing the root structure and cell wall thickness using a Phenom scanning electron microscope as well as measuring cadmium content in the root cell wall, we found that the exodermis of young and mature roots of K. obovata responded to Cd stress through the polymerization of different lignin monomers, forming two different mechanisms: chelation and blocking. Through small RNA sequencing, RLM-5'-RACE and dual luciferase transient expression system, we found that miR397 targets and regulates KoLAC4/17/7 expression. The expression of KoLAC4/17 promoted the accumulation of guaiacyl lignin during lignification and enhanced the binding of cadmium to the cell wall. Meanwhile, KoLAC7 expression promotes the accumulation of syringyl lignin during lignification, which enhances the obstruction of cadmium and improves the tolerance to cadmium. These findings enhance our understanding of the molecular mechanisms underlying the differential lignification of the root exodermis of K. obovata in response to cadmium stress, and provide scientific guidance for the conservation of mangrove forests under heavy metal pollution.


Assuntos
Cádmio , Lignina , MicroRNAs , Raízes de Plantas , Lignina/química , Cádmio/toxicidade , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , MicroRNAs/metabolismo , MicroRNAs/genética , Estresse Fisiológico/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Polimerização/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Araceae/efeitos dos fármacos , Araceae/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética
11.
Colloids Surf B Biointerfaces ; 238: 113885, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38574405

RESUMO

We demonstrate light-triggered dynamic covalent assembly of a linear short tetrapeptide containing two terminal cysteine residues in an AND logic manner. A photobase generator is introduced to accomplish light-mediated pH regulation to increase the reduction potential of thiols in the tetrapeptide, which activates its oxidative polymerization through disulfide bonds. Interestingly, it is elucidated that under light irradiation, mere co-existence of photobase generator and the oxidizing agent permits the polymerization performance of this tetrapeptide. Hence, a light-triggered AND logic dynamic covalent assembly of a tetrapeptide is achieved. Further, upon redox response, the reversible aggregation and disaggregation can be transformed for numerous times due to the dynamic covalent feature of disulfide bond. As a comparison, no assembly occurs for a short peptide containing one terminal cysteine residue under the same stimuli condition. This work offers a new approach to remotely control programmable molecular assembly of short linear peptides based on dynamic covalent bond, holding great potential in wide bioapplications.


Assuntos
Luz , Concentração de Íons de Hidrogênio , Oligopeptídeos/química , Oxirredução , Polimerização , Cisteína/química , Dissulfetos/química , Compostos de Sulfidrila/química , Lógica
12.
J Inorg Biochem ; 256: 112548, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38593610

RESUMO

Neuromelanin (NM) plays a well-established role in neurological disorders pathogenesis; the mechanism of action is still discussed and the investigations in this field are limited by NM's complex and heterogeneous composition, insolubility, and low availability from human brains. An alternative can be offered by synthetic NM obtained from dopamine (DA) oxidative polymerization; however, a deep knowledge of the influence of both physicochemical parameters (T, pH, ionic strength) and other compounds in the reaction media (buffer, metal ions, other catecholamines) on DA oxidation process and, consequently, on synthetic NM features is mandatory to develop reliable NM preparation methodologies. To partially fulfill this aim, the present work focuses on defining the role of temperature, buffer and metal ions on both DA oxidation rate and DA oligomer size. DA oxidation in the specific conditions is monitored by UV-Vis spectroscopy and Principal Component Analysis (PCA) is run either on the raw spectra to model the background absorption increase, related to small DA oligomers formation, or on their first derivative to rationalize DA consumption. After having studied three case studies, 3-Way PCA is applied to directly evaluate the effect of temperature and buffer type on DA oxidation in the presence of different metal ions. Despite the proof-of-concept nature of the work and the number of compounds still to be included in the investigation, the preliminary results and the possibility to further expand the chemometric approach represent an interesting contribution to the field of in vitro simulation of NM synthesis.


Assuntos
Dopamina , Melaninas , Oxirredução , Polimerização , Análise de Componente Principal , Dopamina/metabolismo , Dopamina/química , Melaninas/química , Melaninas/metabolismo , Melaninas/biossíntese , Temperatura , Humanos , Soluções Tampão , Metais/química , Concentração de Íons de Hidrogênio
13.
Water Sci Technol ; 89(8): 2020-2034, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38678406

RESUMO

Nanofiltration (NF) membrane technology has been widely used in the removal of salts and trace organic pollutants, such as pharmaceuticals and personal care products (PPCPs), due to its superiority. A positive-charged composite NF membrane with an active skin layer was prepared by polyethyleneimine (PEI), trimethyl benzene chloride, and quaternate chitosan (HTCC) through second interfacial polymerization on the polyethersulfone ultrafiltration membrane. The physicochemical properties of the nanocomposite membrane were investigated using surface morphology, hydrophilicity, surface charge, and molecular weight cut-off (MWCO). The influence of the concentration and reaction time of PEI and HTCC was documented. The optimized membrane had a MWCO of about 481 Da and possessed a pure water permeability of 25.37 L·m-2·h-1·MPa-1. The results also exhibited salt rejection ability as MgCl2 > CaCl2 > MgSO4 > Na2SO4 > NaCl > KCl, showing a positive charge on the fabricated membrane. In addition, the membrane had higher rejection to atenolol, carbamazepine, amlodipine, and ibuprofen at 89.46, 86.02, 90.12, and 77.21%, respectively. Moreover, the anti-fouling performance and stability of the NF membrane were also improved.


Assuntos
Quitosana , Membranas Artificiais , Poluentes Químicos da Água , Quitosana/química , Poluentes Químicos da Água/química , Preparações Farmacêuticas/química , Purificação da Água/métodos , Polimerização , Sais/química , Ultrafiltração/métodos , Filtração/métodos
14.
J Indian Prosthodont Soc ; 24(2): 186-195, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38650344

RESUMO

AIM: (1) To compare the temperature rise in the pulp chamber with different resin materials used for making provisional fixed partial dentures in anterior and posterior region while using Polyvinylsiloxane impression materials as matrix. (2) To identify a superior provisionalization material based on the amount of heat dissipated suitable for anterior and posterior provisional fixed partial denture fabrication. SETTINGS AND DESIGN: Temporary crowns and bridges are integral to Fixed Prosthodontics. It has been observed that conventional fixed prosthesis temporisation materials release heat due to the exothermic polymerisation reaction. When such a provisional material is directly let to set on a vital tooth, the heat transfer causes irreversible changes in the pulp tissue depending of the degree of change. Hence, this study observes amount of heat generation in various materials during temporisation procedure, by simulating similar conditions. MATERIALS AND METHODS: Two Models were fabricated, one simulating missing lateral incisor (Model A) and another simulating missing first molar (Model B). Intact maxillary central incisors and canine for Model A and intact mandibular Second Premolar and Second Molar were selected to act as abutments. These abutment teeth were fitted with the tip of a K-type Thermocouple inside their pulp chambers and these were connected to a digital thermometer. Five temporisation materials were chosen for fabrication of temporary crowns through Direct technique. (1) polymethy methacrylate (Self Cure acrylic), (2) bisacryl composite (Protemp 4), (3) visible light cure urethane dimethacrylate (Revotec LC), (4) barium glass and fumed silica infused methacrylate (Dentsply Integrity) and (5)nano-hybrid composite (VOCO Structur 3). Ten observations were made for each provisional material on each model. During each observation, temperature rise was recorded at 30s interval from the time of application, through the peak and till a decrease in temperature is observed. Polyvinyl siloxane was used as matrix for all except light cure resin, where polypropylene sheet was used. STATISTICAL ANALYSIS USED: Anova test used for statistical. RESULTS: ANOVA test revealed that there was a significant difference in the temperature changes associated with the provisional restorative materials used. Among the five, polymethy methacrylate (self cure resin) showed the maximum rise in temperature, followed by bisacryl composite (Protemp 4), visible light cure urethane dimethacrylate (Revotec LC), barium glass and fumed silica infused methacrylate (Dentsply Integrity) and nano-hybrid composite (VOCO Structur 3). There was no comparable difference between Model A and B but an overall reduction of temperature rise was observed in model B. CONCLUSION: VOCO Structur 3 showed the least temperature rise in the pulp chamber, and overall temperature rise was less for model B which can be attributed to the residual dentin thickness.


Assuntos
Polimerização , Humanos , Cavidade Pulpar , Siloxanas/química , Técnicas In Vitro , Teste de Materiais/métodos , Resinas Compostas/química , Restauração Dentária Temporária/métodos , Prótese Parcial Fixa , Temperatura , Materiais para Moldagem Odontológica/química , Materiais Dentários/química
15.
Int J Biol Macromol ; 267(Pt 2): 131565, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38614184

RESUMO

Endopolygalacturonases are crucial pectinases known for their efficient and sustainable pectin depolymerization activities. The present study identified a novel gene encoding endopolygalacturonase from an acidic mine tailing metagenome. The putative gene showed a maximum identity of 67.55 % with an uncharacterized peptide sequence from Flavobacterium fluvii. The gene was cloned and expressed in a heterologous host, E. coli. Biochemical characterization of the novel endopolygalacturonase enzyme variant (EPHM) showed maximum activity at 60 °C and at 5.0 pH, while retaining 50 % activity under the temperature and pH range of 20 °C to 70 °C for 6 h, and 3.0 to 10.0 for 3 h, respectively. The enzyme exhibited tolerance to different metal ions. EPHM was characterized for the depolymerization of methylated pectin into pectic oligosaccharides. Further, its utility was established for fruit juice clarification, as endorsed by high transmittance, significant viscosity reduction, and release of reducing sugars in the treated fruit juice samples.


Assuntos
Sucos de Frutas e Vegetais , Pectinas , Poligalacturonase , Pectinas/metabolismo , Pectinas/química , Poligalacturonase/metabolismo , Poligalacturonase/química , Poligalacturonase/genética , Sucos de Frutas e Vegetais/análise , Concentração de Íons de Hidrogênio , Temperatura , Clonagem Molecular , Polimerização , Oligossacarídeos/química
16.
J Mater Chem B ; 12(19): 4574-4583, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38683108

RESUMO

Lipoic acid (LA) is a versatile antioxidant that has been used in the treatment of various oxidation-reduction diseases over the past 70 years. Owing to its large five-membered ring tension, the dynamic disulfide bond of LA is highly active, enabling the formation of poly(lipoic acid) (PLA) via ring-opening polymerization (ROP). Herein, we first summarize disulfide-mediated ROP polymerization strategies, providing basic routes for designing and preparing PLA-based materials. PLA, as a biologically derived, low toxic, and easily modified material, possesses dynamic disulfide bonds and universal non-covalent carboxyl groups. We also shed light on the biomedical applications of PLA-based materials based on their biological and structural features and further divide recent works into six categories: antibacterial, anti-inflammation, anticancer, adhesive, flexible electronics, and 3D-printed tissue scaffolds. Finally, the challenges and future prospects associated with the biomedical applications of PLA are discussed.


Assuntos
Materiais Biocompatíveis , Ácido Tióctico , Ácido Tióctico/química , Ácido Tióctico/farmacologia , Humanos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/síntese química , Polímeros/química , Polímeros/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Alicerces Teciduais/química , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Polimerização , Antioxidantes/química , Antioxidantes/farmacologia
17.
J Chromatogr A ; 1722: 464864, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38598890

RESUMO

In this study, a novel piperidinium-sulfonate based zwitterionic hydrophilic monolith was prepared through thermally initiated co-polymerization of a piperidinium-sulfonate monomer 3-(4-((methacryloyloxy)methyl)-1-methylpiperidin-1-ium-1-yl)propane-1-sulfonate (MAMMPS), and a hydrophilic crosslinker N,N'-methylenebisacrylamide (MBA) using n-propanol and H2O as porogenic system. Satisfactory mechanical and chemical stabilities, good repeatability and high column efficiency (120,000 N/m) were obtained on the optimal monolith. The resulting poly(MAMMPS-co-MBA) monolith showed a typical HILIC retention behavior over an ACN content range between 5 and 95 %. Furthermore, this column exhibited good separation performance for various polar compounds. Compared to quaternary ammonium-sulfonate based zwitterionic hydrophilic monolith, i.e. poly(N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl)ammonium betaine-co-MBA), the poly(MAMMPS-co-MBA) monolith displayed stronger retention and better selectivity for the tested phenolic and amine compounds at different pH conditions. Finally, this column was applied for the separation of six sulfonamide antibiotics, and the analytical characteristics of the method were evaluated in terms of precision, repeatability, limits of detection (LOD) and quantitation (LOQ). Overall, this study not only developed a novel HILIC monolithic column, but also proved the potential of piperidinium-sulfonate based zwitterionic chemistry as stationary phase, which further increased the structure diversity of zwitterionic HILIC stationary phases.


Assuntos
Interações Hidrofóbicas e Hidrofílicas , Piperidinas , Piperidinas/isolamento & purificação , Piperidinas/química , Reprodutibilidade dos Testes , Ácidos Sulfônicos/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Acrilamidas/química , Polimerização , Acetonitrilas/química
18.
Nat Commun ; 15(1): 3247, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622169

RESUMO

Photo-crosslinking polymerization stands as a fundamental pillar in the domains of chemistry, biology, and medicine. Yet, prevailing strategies heavily rely on ultraviolet/visible (UV/Vis) light to elicit in situ crosslinking. The inherent perils associated with UV radiation, namely the potential for DNA damage, coupled with the limited depth of tissue penetration exhibited by UV/Vis light, severely restrict the scope of photo-crosslinking within living organisms. Although near-infrared light has been explored as an external excitation source, enabling partial mitigation of these constraints, its penetration depth remains insufficient, particularly within bone tissues. In this study, we introduce an approach employing X-ray activation for deep-tissue hydrogel formation, surpassing all previous boundaries. Our approach harnesses a low-dose X-ray-activated persistent luminescent phosphor, triggering on demand in situ photo-crosslinking reactions and enabling the formation of hydrogels in male rats. A breakthrough of our method lies in its capability to penetrate deep even within thick bovine bone, demonstrating unmatched potential for bone penetration. By extending the reach of hydrogel formation within such formidable depths, our study represents an advancement in the field. This application of X-ray-activated polymerization enables precise and safe deep-tissue photo-crosslinking hydrogel formation, with profound implications for a multitude of disciplines.


Assuntos
Hidrogéis , Raios Ultravioleta , Masculino , Animais , Bovinos , Ratos , Hidrogéis/química , Raios X , Polimerização , Raios Infravermelhos
19.
ACS Macro Lett ; 13(4): 461-467, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38574342

RESUMO

Protein-polymer conjugates combine the unique properties of both proteins and synthetic polymers, making them important materials for biomedical applications. In this work, we synthesized and characterized protein-branched polymer bioconjugates that were precisely designed to retain protein functionality while preventing unwanted interactions. Using chymotrypsin as a model protein, we employed a controlled radical branching polymerization (CRBP) technique utilizing a water-soluble inibramer, sodium 2-bromoacrylate. The green-light-induced atom transfer radical polymerization (ATRP) enabled the grafting of branched polymers directly from the protein surface in the open air. The resulting bioconjugates exhibited a predetermined molecular weight, well-defined architecture, and high branching density. Conformational analysis by SEC-MALS validated the controlled grafting of branched polymers. Furthermore, enzymatic assays revealed that densely grafted polymers prevented protein inhibitor penetration, and the resulting conjugates retained up to 90% of their enzymatic activity. This study demonstrates a promising strategy for designing protein-polymer bioconjugates with tunable sieving behavior, opening avenues for applications in drug delivery and biotechnology.


Assuntos
Quimotripsina , Polímeros , Quimotripsina/metabolismo , Polimerização , Proteínas de Membrana
20.
Compr Rev Food Sci Food Saf ; 23(3): e13352, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38634188

RESUMO

A-type proanthocyanidins (PAs) are a subgroup of PAs that differ from B-type PAs by the presence of an ether bond between two consecutive constitutive units. This additional C-O-C bond gives them a more stable and hydrophobic character. They are of increasing interest due to their potential multiple nutritional effects with low toxicity in food processing and supplement development. They have been identified in several plants. However, the role of A-type PAs, especially their complex polymeric form (degree of polymerization and linkage), has not been specifically discussed and explored. Therefore, recent advances in the physicochemical and structural changes of A-type PAs and their functional properties during extraction, processing, and storing are evaluated. In addition, discussions on the sources, structures, bioactivities, potential applications in the food industry, and future research trends of their derivatives are highlighted. Litchis, cranberries, avocados, and persimmons are all favorable plant sources. Α-type PAs contribute directly or indirectly to human nutrition via the regulation of different degrees of polymerization and bonding types. Thermal processing could have a negative impact on the amount and structure of A-type PAs in the food matrix. More attention should be focused on nonthermal technologies that could better preserve their architecture and structure. The diversity and complexity of these compounds, as well as the difficulty in isolating and purifying natural A-type PAs, remain obstacles to their further applications. A-type PAs have received widespread acceptance and attention in the food industry but have not yet achieved their maximum potential for the future of food. Further research and development are therefore needed.


Assuntos
Proantocianidinas , Humanos , Proantocianidinas/análise , Proantocianidinas/química , Frutas/química , Polimerização , Plantas , Estado Nutricional
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