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1.
RSC Adv ; 14(28): 20105-20112, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38915334

RESUMEN

A process employing extrusion was used to produce multicore microcapsules composed of multiple beads. The inner beads were made from κ-carrageenan (κ-c), a thermo-responsive linear sulphated polymer whose gelling temperature ranges at 40-60 °C, depending on the concentration of κ-c polymer and the amount of potassium chloride used for gelation. The resulting beads were then enveloped by chitosan through gelation with sodium triphosphate. The pesticide ammonium glufosinate was encapsulated in the κ-c/chitosan multicore microcapsules for demonstration of controlled release of the encapsulant. It was found that in response to an external stimulus, such as elevated temperature or solar simulation, the microcapsules exhibit the gradual release of encapsulated pesticide molecules from multicore microcapsules, compared with beads only. This process of making multicore microcapsules can be extended to other polymer pairs based on applications. This work is relevant to agriculture, where the controlled-release of the pesticides or fertilizers could be triggered by the sun and/or temperature changes, thus extending the residual period of the chemicals as well as decreasing the extent of pollution by leaching of abundant chemicals.

2.
Macromol Rapid Commun ; : e2400097, 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38499007

RESUMEN

Smart nanoassemblies degradable through the cleavage of acid-labile linkages have attracted significant attention because of their biological relevance found in tumor tissues. Despite their high potential to achieve controlled/enhanced drug release, a systematic understanding of structural factors that affect their pH sensitivity remains challenging, particulary in the consruction of effective acid-degradable shell-sheddable nanoassemblies. Herein, the authors report the synthesis and acid-responsive degradation through acid-catalyzed hydrolysis of three acetal and ketal diols and identify benzaldehyde acetal (BzAA) exhibiting optimal hydrolysis profiles in targeted pH ranges to be a suitable candidate for junction acid-labile linkage. The authors explore the synthesis and aqueous micellization of well-defined poly(ethylene glycol)-based block copolymer bearing BzAA linkage covalently attached to a polymethacrylate block for the formation of colloidally-stable nanoassemblies with BzAA groups at core/corona interfaces. Promisingly, the investigation on acid-catalyzed hydrolysis and disassembly shows that the formed nanoassemblies meet the criteria for acid-degradable shell-sheddable nanoassemblies: slow degradation at tumoral pH = 6.5 and rapid disassembly at endo/lysosomal pH = 5.0, while colloidal stability at physiological pH = 7.4. This work guides the design principle of acid-degradable shell-sheddable nanoassemblies bearing BzAA at interfaces, thus offering the promise to address the PEG dilemma and improve endocytosis in tumor-targeting drug delivery.

3.
Curr Protoc ; 3(2): e691, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36840706

RESUMEN

The protocols described in this article provide details regarding the synthesis and characterization of a disulfide containing linker phosphoramidite for terminal functionalization of synthetic oligonucleotides. The linker is first synthesized from 6-mercaptohexanol in two steps and is incorporated at the 5' end of short DNA oligonucleotides using automated solid-phase synthesis. The linker contains a terminal tosylate group which is post-synthetically displaced by altering the deprotection conditions to yield a variety of functional handles (N3 , NH2 , OMe, SH) or alternatively, the tosylate can be displaced directly with primary amines such as tert-butylamine. The linker system is also compatible with RNA oligonucleotides enabling the introduction of various functional handles (N3 , NH2 ). The protocol outlined in this procedure provides access to a versatile linker for the terminal functionalization of oligonucleotides containing a disulfide bond which may serve useful in the synthesis of reduction-responsive oligonucleotide conjugates. As a proof of concept, in this protocol the linker is used to modify a dT10 oligonucleotide and then conjugated by copper(I)-mediated azide-alkyne cycloaddition (CuAAC) to an alkyne-modified poly(ethylene glycol) which shows concentration dependent release of the oligonucleotide upon treatment with 1,4-dithiothreitol, a reducing agent. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Preparation of disulfide linker phosphoramidite 3 Basic Protocol 2: Synthesis, functionalization, and characterization of DNA oligonucleotides containing disulfide linker phosphoramidite 3 Basic Protocol 3: Displacement of terminal tosylate functionalized DNA with primary aliphatic amines Basic Protocol 4: Synthesis of oligonucleotide-PEG conjugate Support Protocol: Preparation of PEG-alkyne.


Asunto(s)
Disulfuros , Oligonucleótidos , Oligonucleótidos/química , Antígenos , Aminas , Alquinos/química
4.
Chemosphere ; 312(Pt 1): 137240, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36379429

RESUMEN

The development of nanofibrous oil-water separation materials is explosively progressing, but the remarkably low productivity is the main factor hindering their practical application. In this study, biodegradable polybutylene succinate (PBS) nanofibers with excellent productivity (27.0 g/h per nozzle) were successfully fabricated using the solution blow spinning (SBS) process, breaking away from the conventional electrospinning method. The prepared PBS nanofibers exhibited extremely thin fiber diameters (130 nm) with high porosity (97.4%). Without any chemical modification or inorganic/organic hybrid materialization, the PBS nanofibrous membrane showed excellent oil adsorption capacity (minimum: 18.7 g/g and maximum: 38.5 g/g) and separation efficiency; water and oil mixtures (99.4-99.98%) and emulsions (98.1-99.5%) compared to conventional organic polymer-based nanofibers. In terms of disposal after use, this biodegradable nanofibrous membrane was able to return to nature through hydrolysis and biodegradation processes.


Asunto(s)
Nanofibras , Nanofibras/química , Interacciones Hidrofóbicas e Hidrofílicas , Polímeros , Porosidad
5.
Int J Biol Macromol ; 222(Pt A): 546-561, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36150574

RESUMEN

The incidence and of bacterial infections, and resulting mortality, among cancer patients is growing dramatically, worldwide. Several therapeutics have been reported to have dual anticancer and antibacterial activity. However, there is still an urgent need to develop new drug delivery strategies to improve their clinical efficacy. Therefore, this study aimed to develop a novel acid cleavable prodrug (HA-Cip) from ciprofloxacin and hyaluronic acid to simultaneously enhance the anticancer and antibacterial properties of Cip as a superior drug delivery system. HA-Cip was synthesised and characterised (FT-IR, HR-MS, and H1 NMR). HA-Cip generated stable micelles with an average particle size, poly dispersion index (PDI) and zeta potential (ZP) of 237.89 ± 25.74 nm, 0.265 ± 0.013, and -17.82 ± 1.53 mV, respectively. HA-Cip showed ≥80 % cell viability against human embryonic kidney 293 cells (non-cancerous cells), ˂0.3 % haemolysis; and a faster pH-responsive ciprofloxacin release at pH 6.0. HA-Cip showed a 5.4-fold improvement in ciprofloxacin in vitro anticancer activity against hepatocellular cancer (HepG2) cells; and enhanced in vitro antibacterial activity against Escherichia coli and Klebsiella pneumoniae at pH 6.0. Our findings show HA-Cip as a promising prodrug for targeted delivery of ciprofloxacin to efficiently treat bacterial infections associated, and/or co-existing, with cancer.


Asunto(s)
Infecciones Bacterianas , Neoplasias , Profármacos , Humanos , Ciprofloxacina/farmacología , Ciprofloxacina/química , Profármacos/farmacología , Profármacos/uso terapéutico , Ácido Hialurónico/química , Espectroscopía Infrarroja por Transformada de Fourier , Neoplasias/tratamiento farmacológico , Antibacterianos/química , Infecciones Bacterianas/tratamiento farmacológico , Sistemas de Liberación de Medicamentos
6.
Org Lett ; 24(30): 5579-5583, 2022 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-35863757

RESUMEN

The synthesis and incorporation of a tosylated phosphoramidite linker containing a disulfide bond is described. Incorporation of the linker into short DNA and RNA oligomers proceeded efficiently using automated solid phase synthesis. Treatment of the support bound oligonucleotide followed by cleavage from the solid support provided a variety of common functional handles, expanding the strategies of bifunctional modification of synthetic oligonucleotides for conjugation applications.


Asunto(s)
Disulfuros , Oligonucleótidos , ADN , Oligonucleótidos/química , ARN/química , Técnicas de Síntesis en Fase Sólida
7.
Polymers (Basel) ; 14(11)2022 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-35683912

RESUMEN

Nitric oxide (NO) plays a critical role as an important signaling molecule for a variety of biological functions, particularly inhibiting cell proliferation or killing target pathogens. To deliver active radical NO gaseous molecule whose half-life is a few seconds in a stable state, the design and development of effective exogenous NO supply nanocarriers are essential. Additionally, the delivery of desired drugs with NO can produce synergistic effects. Herein, we report a new approach that allows for the fabrication of dual ultrasound (US)/glutathione (GSH)-responsive perfluorocarbon (PFC) nanodroplets for the controlled release of model drug and passive release of safely incorporated NO. The approach centers on the synthesis of a disulfide-labeled amphiphilic block copolymer and its use as a GSH-degradable macromolecular emulsifier for oil-in-water emulsification process of PFC. The fabricated PFC nanodroplets are colloidally stable and enable the encapsulation of both NO and model drugs. Encapsulated drug molecules are synergistically released when ultrasound and GSH are presented, while NO molecules are passively but rapidly released. Our preliminary results demonstrate that the approach is versatile and can be extended to not only GSH-responsive but also other stimuli-responsive block copolymers, thereby allowing for the fabrication of broad choices of stimuli-responsive (smart) PFC-nanodroplets in aqueous solution for dual delivery of drug and NO therapeutics.

8.
ACS Appl Mater Interfaces ; 14(15): 17806-17817, 2022 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-35385641

RESUMEN

Triboelectric nanogenerators (TENGs), a newly developed energy harvesting device that converts surrounding environmental mechanical stimuli into electricity, have been significantly explored as an ideal long-term power source for electrical devices. Despite recent advances, the development of advanced TENG devices with sufficient outputs to sustainably power electronic devices and rapid self-healability under mild conditions to improve their lifetime and function is highly demanded. Here, we report a robust self-healable and reprocessable TENG fabricated with a covalent adaptive network based on mechanically strong fluorinated poly(hindered urea) (F-PHU) integrated with ionic liquid as an efficient dielectric material to improve its triboelectric efficiency and self-healing capability simultaneously. The synthesis and integration of a well-defined reactive copolymer having both pendant fluorinated and t-butylamino bulky groups are the key to fabricate robust F-PHU networks containing fluorinated dangling chains that can interact with ionic liquids to induce ionic polarization, which raises the dielectric constant and thus increases triboelectric performance. They also are cross-linked with dynamic bulky urea linkages for rapid self-healability and high reprocessability through their reversible exchange reactions at moderate temperatures. The developed ionic F-PHU materials exhibit a high TENG output performance (power density of 173.0 mW/m2) as well as high TENG output recovery upon repairing their surface damages. This work demonstrates that such a synergistic design of triboelectric ionic F-PHU materials could have great potential for applications requiring high-performance and long-lasting energy harvesting.

9.
Macromol Rapid Commun ; 42(20): e2100391, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34418209

RESUMEN

Polyurethane (PU) has not only been widely used in the daily lives, but also extensively explored as an important class of the essential polymers for various applications. In recent years, significant efforts have been made on the development of self-healable PU materials that possess high performance, extended lifetime, great reliability, and recyclability. A promising approach is the incorporation of covalent dynamic bonds into the design of PU covalently crosslinked polymers and thermoplastic elastomers that can dissociate and reform indefinitely in response to external stimuli or autonomously. This review summarizes various strategies to synthesize self-healable, reprocessable, and recyclable PU materials integrated with dynamic (reversible) Diels-Alder cycloadduct, disulfide, diselenide, imine, boronic ester, and hindered urea bond. Furthermore, various approaches utilizing the combination of dynamic covalent chemistries with nanofiller surface chemistries are described for the fabrication of dynamic heterogeneous PU composites.


Asunto(s)
Elastómeros , Poliuretanos , Polímeros , Reproducibilidad de los Resultados
10.
ACS Appl Mater Interfaces ; 13(28): 32916-32929, 2021 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-34229427

RESUMEN

The present work demonstrates the efficient design of ultrasmall porous carbon nanospheres with tailored sizes (5-40 nm in diameter) and optimized intrasphere textural properties for high-rate high-energy supercapacitor application. The carbon nanospheres are synthesized via a miniemulsion polymerization technique followed by KOH activation. It is shown that dual-step activation renders enlarged intrasphere micropores/mesopores, facilitating enhanced ion transports. Meanwhile, a decrease in nanosphere size from 40 to 5 nm significantly improves the rate performance, demonstrating the pronounced size effects due to enhanced intrasphere ion transport. The optimum dual-step-activated carbon nanosphere sample with an average sphere size of 5 nm, ACNS5-2, shows the high specific capacitances along with outstanding high-rate capabilities in both aqueous (272 F g-1 at 0.5 A g-1 and 81.6% of retention at 200 A g-1) and EMIMBF4 (223 F g-1 at 0.5 A g-1 and 67.2% of retention at 100 A g-1) electrolytes in symmetrical two-electrode cells. In EMIMBF4, ACNS5-2 displays a high energy density of 48 Wh kg-1 at a high power density of 14 kW kg-1, suggesting excellent energy storage efficiency. Moreover, the performance of ACNS5-2 competes well with or is superior to some best-performing porous carbon-based materials reported in the literature for supercapacitor applications even at lowered temperatures (at -20 °C: 150 F g-1 at 0.5 A g-1 with a capacitance retention of 64% at 10 A g-1) and high mass loading (8 mg cm-2: 205 F g-1 at 0.5 A g-1 with a capacitance retention of 64.5% at 20 A g-1). Our results, combined with structure-performance relationships, offer valuable guidelines for the rational design of carbon nanomaterials of optimum supercapacitive performances.

11.
Macromol Rapid Commun ; 42(16): e2100262, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34050688

RESUMEN

Acid-degradable (or acid-cleavable) polymeric nanoassemblies have witnessed significant progress in anti-cancer drug delivery. However, conventional nanoassemblies designed with acid-cleavable linkages at a single location have several challenges, such as, sluggish degradation, undesired aggregation of degraded products, and difficulty in controlled and on-demand drug release. Herein, a strategy that enables the synthesis of acid-cleavable nanoassemblies labeled with acetaldehyde acetal groups in both hydrophobic cores and at core/corona interfaces, exhibiting synergistic response to acidic pH at dual locations and thus inducing rapid drug release is reported. The systematic analyses suggest that the acid-catalyzed degradation and disassembly are further enhanced by decreasing copolymer concentration (i.e., increasing proton/acetal mole ratio). Moreover, incorporation of acid-ionizable imidazole pendants in the hydrophobic cores improve the encapsulation of doxorubicin, the anticancer drug, through π-π interactions and enhance the acid-catalyzed hydrolysis of acetal linkages situated in the dual locations. Furthermore, the presence of the imidazole pendants induce the occurrence of core-crosslinking that compensates the kinetics of acetal hydrolysis and drug release. These results, combined with in vitro cell toxicity and cellular uptake, suggest the versatility of the dual location acid-degradation strategy in the design and development of effective intracellular drug delivery nanocarriers.


Asunto(s)
Micelas , Polímeros , Doxorrubicina/farmacología , Portadores de Fármacos , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Imidazoles
12.
Macromol Rapid Commun ; 42(12): e2000514, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33988899

RESUMEN

The development of heterogeneous covalent adaptable networks (CANs) embedded with carbon nanotubes (CNTs) that undergo reversible dissociation/recombination through thermoreversibility has been significantly explored. However, the carbon nanotube (CNT)-incorporation methods based on physical mixing and chemical modification could result in either phase separation due to structural incompatibility or degrading conjugation due to a disruption of π-network, thus lowering their intrinsic charge transport properties. To address this issue, the versatility of a macromolecular engineering approach through thermoreversibility by physical modification of CNT surfaces with reactive multidentate block copolymers (rMDBCs) is demonstrated. The formed CNTs stabilized with rMDBCs (termed rMDBC/CNT colloids) bearing reactive furfuryl groups is functioned as a multicrosslinker that reacts with a polymaleimide to fabricate robust heterogeneous polyurethane (PU) networks crosslinked through dynamic Diels-Alder (DA)/retro-DA chemistry. Promisingly, the fabricated PU network gels in which CNTs through rMDBC covalently embedded are flexible and robust to be bendable as well as exhibit self-healing elasticity and enhanced conductivity.


Asunto(s)
Nanotubos de Carbono , Elasticidad , Conductividad Eléctrica , Polímeros , Poliuretanos
13.
Polymers (Basel) ; 13(4)2021 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-33672667

RESUMEN

The focus on high-strength and functional natural fiber-based composite materials is growing as interest in developing eco-friendly plastics and sustainable materials increases. An eco-friendly fibrous composite with excellent mechanical properties was prepared by applying the bamboo-derived nano and microfiber multiscale hybridization phenomenon. As a result, the cellulose nanofibers simultaneously coated the micro-bamboo fiber surface and adhered between them. The multiscale hybrid phenomenon implemented between bamboo nano and microfibers improved the tensile strength, elongation, Young's modulus, and toughness of the fibrous composite. The enhancement of the fibrous preform mechanical properties also affected the reinforcement of biodegradable fiber-reinforced plastic (FRP). This eco-friendly nano/micro fibrous preform can be extensively utilized in reinforced preforms for FRPs and other green plastic industry applications.

14.
Macromol Rapid Commun ; 41(22): e2000394, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32964550

RESUMEN

The development of effective approaches to synthesize smart amphiphilic block copolymers (ABPs) exhibiting acid-responsive degradation through the cleavage of acid-labile imine bonds is extensively explored for controlled release of encapsulated biomolecules, particularly in drug delivery. Here, a new approach based on direct polymerization utilizing a controlled radical polymerization technique to synthesize acid-degradable ABPs bearing pendant imine linkages in hydrophobic block is reported. The approach centers on the synthesis of a novel methacrylate bearing benzoic imine group that can be polymerized to form the hydrophobic imine pendant block. The formed ABPs respond to mild acidic pHs equivalent to tumoral and endosomal/lysosomal acidic environments. This causes the dissociation of self-assembled nanoassemblies through change in their hydrophilic/hydrophobic balance upon the cleavage of pendant imine linkages to the corresponding aldehyde and primary amine, thus leading to the enhanced release of encapsulated drugs. The proof-of-concept results suggest that this robust approach is versatile to further design advanced nanoassemblies responding to dual/multiple stimuli, thus being more effective to intracellular drug delivery.


Asunto(s)
Iminas , Micelas , Interacciones Hidrofóbicas e Hidrofílicas , Polimerizacion , Polímeros
15.
ACS Nano ; 14(9): 11442-11451, 2020 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-32840992

RESUMEN

In recent years, the advent of highly deformable and healable electronics is exciting and promising for next-generation electronic devices. In particular, self-healable triboelectric nanogenerators (SH-TENGs) serve as promising candidates based on the combination of the triboelectric effect, electrostatic induction, and self-healing action. However, the majority of SH-TENGs have been devised with weak polymeric networks that are healed with reversible supramolecular interactions or disulfides, thus resulting in poor mechanical properties and low resistance to creeping. To address this issue, we demonstrate the integration of mechanically strong and self-healable poly(hindered urea) (PHU) network in the fabrication of effective TENGs. The designed PHU network is flexible but shows greater mechanical property of tensile strength as high as 1.7 MPa at break. The network is capable of self-healing quickly and repeatedly as well as being reprocessable under mild conditions, enabling the recovery of triboelectric performances after the complete healing of the damaged surfaces. Furthermore, the interfacial-polarization-induced enhancement of dielectric constant endows our SH-TENG with the highest triboelectric output performance (169.9 V/cm2) among the reported healable TENGs. This work presents an avenue to the development of mechanical energy-harvesting devices and self-powered sensors with excellent stretchability, high recoverability, and good mechanical strength.

16.
Mol Pharm ; 17(10): 3979-3989, 2020 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-32852957

RESUMEN

Gene therapy holds great promise for the treatment of acquired genetic disorders such as cancer with reduced side effects compared to chemotherapy. For gene therapy to be successful, it is crucial to develop efficient and nontoxic gene carriers to overcome the poor in vivo stability and low cellular uptake of nucleic acid-based therapeutic agents. Here, we report a new and versatile approach exploring a combination of hydrophobic modifications and dual-stimuli-responsive degradation (SRD) for controlled gene delivery with amphiphilic block copolymer-based nanocarriers. The block copolymer, synthesized by atom transfer radical polymerization, is designed with an acid-labile acetal linkage at the block junction and a pendant disulfide group in the hydrophobic block. The incorporation of labile linkages enables both disulfide-core-cross-linking and dual-location dual-acid/reduction-responsive degradation (DL-DSRD). Furthermore, the disulfide linkages integrated as hydrophobic moieties facilitate the nucleic acids to condense into nanometer-sized micelleplexes through electrostatic interactions of pendant dimethylamino groups with the anionic phosphate groups of the nucleic acids. Our preliminary results demonstrate that the DL-DSRD approach through hydrophobic modification is a robust platform in the development of gene delivery systems with enhanced colloidal stability, reduced cytotoxicity, and improved gene transfection efficiency.


Asunto(s)
Silenciador del Gen , Técnicas de Transferencia de Gen , Terapia Genética/métodos , Nanopartículas/química , Polímeros/química , Cationes/química , Genes Reporteros , Glutatión/química , Proteínas Fluorescentes Verdes/genética , Células HeLa , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Micelas , Neoplasias/genética , Neoplasias/terapia
17.
ACS Omega ; 5(7): 3734-3742, 2020 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-32118189

RESUMEN

We report a thermoresponsive double hydrophilic block copolymer degradable in response to dual reduction and acidic pH at dual locations. The copolymer consists of a poly(ethylene oxide) block covalently connected through an acid-labile acetal linkage with a thermoresponsive polymethacrylate block containing pendant oligo(ethylene oxide) and disulfide groups. The copolymer undergoes temperature-driven self-assembly in water to form nanoassemblies with acetal linkages at the core/corona interface and disulfide pendants in the core, exhibiting dual reduction/acid responses at dual locations. The physically assembled nanoaggregates are converted to disulfide-core-crosslinked nanogels through disulfide-thiol exchange reaction, retaining enhanced colloidal stability, yet degraded to water-soluble unimers upon reduction/acid-responsive degradation. Further, the copolymer exhibits improved tunability of thermoresponsive property upon the cleavage of junction acetal and pendant disulfide linkages individually and in combined manner. This work suggests that dual location dual reduction/acid-responsive degradation is a versatile strategy toward effective drug delivery exhibiting disulfide-core-crosslinking capability and disassembly as well as improved thermoresponsive tunability.

18.
ACS Appl Bio Mater ; 3(10): 7219-7227, 2020 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-35019380

RESUMEN

Chronic wounds present a high risk of infection due to delayed and incomplete healing, leading to increased health risks and financial burden to health-care systems. Numerous approaches to promote wound healing have been extensively explored, especially the development of effective wound dressing materials embedded with therapeutic drug molecules. Despite advances made in this area, a remaining challenge to be addressed is the controlled, on-demand release of therapeutic molecules using noncytotoxic stimulus, for example, near-infrared (NIR) excitation. Here, we report a platform that allows for the development of electrospun poly(vinyl alcohol) (PVA) fibrous hybrids embedded with upconverting nanoparticles (UCNPs) and UV-cleavable levofloxacin conjugates for wound dressings. Upon irradiation with NIR light, the excited UCNPs emit UV light around 365 nm, which can cleave the o-nitrobenzyl (ONB) linkage of the levofloxacin conjugates in the PVA fiber, leading to controlled drug release. The release was observed to be triggered only under NIR and UV irradiation, with no effect in the dark. Furthermore, the antibacterial effect against Escherichia coli and Staphylococcus aureus was successfully demonstrated, highlighting the versatility of the electrospun upconverting fiber platform. The development of antibacterial fibrous meshes with on-demand release of encapsulated drugs is imperative for precise treatment of wound infections.

19.
ACS Biomater Sci Eng ; 6(9): 5069-5083, 2020 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-33455300

RESUMEN

We demonstrate microfluidic manufacturing of glutathione (GSH)-responsive polymer nanoparticles (PNPs) with controlled in vitro pharmacological properties for selective drug delivery. This work leverages previous fundamental work on microfluidic control of the physicochemical properties of GSH-responsive PNPs containing cleavable disulfide groups in two different locations (core and interface, DualM PNPs). In this paper, we employ a two-phase gas-liquid microfluidic reactor for the flow-directed manufacturing of paclitaxel-loaded or DiI-loaded DualM PNPs (PAX-PNPs or DiI-PNPs, where DiI is a fluorescent drug surrogate dye). We find that both PAX-PNPs and DiI-PNPs exhibit similar flow-tunable sizes, morphologies, and internal structures to those previously described for empty DualM PNPs. Fluorescent imaging of DiI-PNP formulations shows that microfluidic manufacturing greatly improves the homogeneity of drug dispersion within the PNP population compared to standard bulk microprecipitation. Encapsulation of PAX in DualM PNPs significantly increases its selectivity to cancerous cells, with various PAX-PNP formulations showing higher cytotoxicity against cancerous MCF-7 cells than against non-cancerous HaCaT cells, in contrast to free PAX, which showed similar cytotoxicity in the two cell lines. In addition, the characterization of DualM PNP formulations formed at various microfluidic flow rates reveals that critical figures of merit for drug delivery function-including encapsulation efficiencies, GSH-triggered release rates, rates of cell uptake, cytotoxicities, and selectivity to cancerous cells-exhibit microfluidic flow tunability that mirrors trends in PNP size. These results highlight the potential of two-phase microfluidic manufacturing for controlling both structure and drug delivery function of biological stimuli-responsive nanomedicines toward improved therapeutic outcomes.


Asunto(s)
Nanopartículas , Preparaciones Farmacéuticas , Polímeros de Estímulo Receptivo , Sistemas de Liberación de Medicamentos , Humanos , Microfluídica
20.
ACS Appl Mater Interfaces ; 12(1): 177-190, 2020 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-31820915

RESUMEN

Microfluidic flow-directed self-assembly of biological stimuli-responsive block copolymers is demonstrated with dual-location cleavable linkages at the junction between hydrophilic and hydrophobic blocks and on pendant group within the hydrophobic blocks. On-chip self-assembly within a two-phase microfluidic reactor forms various "DualM" polymer nanoparticles (PNPs), including cylinders and multicompartment vesicles, with sizes and morphologies that are tunable with manufacturing flow rate. Complex kinetically trapped intermediates between shear-dependent states provide the most detailed mechanism to date of microfluidic PNP formation in the presence of flow-variable high shear. Glutathione (GSH)-triggered changes in PNP size and internal structure depend strongly on the initial flow-directed size and internal structure. Upon incubation in GSH, flow-directed PNPs with smaller average sizes showed a faster hydrodynamic size increase (attributed to junction cleavage) and those with higher excess Gibbs free energy showed faster inner compartment growth (attributed to pendant cleavage). These results demonstrate that the combination of chemical control of the location of biologically responsive linkages with microfluidic shear processing offers promising routes for tunable "smart" polymeric nanomedicines.


Asunto(s)
Sistemas de Liberación de Medicamentos , Técnicas Analíticas Microfluídicas , Nanopartículas/química , Polímeros de Estímulo Receptivo/química
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