RESUMEN
Developing nature-inspired nanomaterials with enzymatic activity is essential in combating bacterial biofilms. Here, it is reported that incorporating the carboxylic acid in phenolic/Fe nano-networks can efficiently manipulate their peroxidase-like activity via the acidic microenvironment and neighboring effect of the carboxyl group. The optimal gallic acid/Fe (GA/Fe) nano-networks demonstrate highly enzymatic activity in catalyzing H2 O2 into oxidative radicals, damaging the cell membrane and extracellular DNA in Streptococcus mutans biofilms. Theoretical calculation suggests that the neighboring carboxyl group can aid the H2 O2 adsorption, free radical generation, and catalyst reactivation, resulting in superb catalytic efficiency. Further all-atom simulation suggests the peroxidation of lipids can increase the cell membrane fluidity and permeability. Also, GA/Fe nano-networks show great potential in inhibiting tooth decay and treating other biofilm-associated diseases without affecting the commensal oral flora. This strategy provides a facile and scale-up way to prepare the enzyme-like materials and manipulate their enzymatic activity for biomedical applications.
Asunto(s)
Peroxidasa , Streptococcus mutans , Peroxidasa/metabolismo , Streptococcus mutans/genética , Streptococcus mutans/metabolismo , BiopelículasRESUMEN
As an acute ophthalmic infection, bacterial keratitis (BK) can lead to severe visual morbidity, such as corneal perforation, intraocular infection, and permanent corneal opacity, if rapid and effective treatments are not available. In addition to eradicating pathogenic bacteria, protecting corneal tissue from oxidative damage and promoting wound healing by relieving inflammation are equally critical for the efficient treatment of BK. Besides, it is very necessary to improve the bioavailability of drugs by enhancing the ocular surface adhesion and corneal permeability. In this investigation, therefore, a synergistic antibiotic-antioxidant treatment of BK was achieved based on multifunctional block copolymer vesicles, within which ciprofloxacin (CIP) was simultaneously encapsulated during the self-assembly. Due to the phenylboronic acid residues in the corona layer, these vesicles exhibited enhanced muco-adhesion, deep corneal epithelial penetration, and bacteria-targeting, which facilitated the drug delivery to corneal bacterial infection sites. Additionally, the abundant thioether moieties in the hydrophobic membrane enabled the vesicles to both have ROS-scavenging capacity and accelerated CIP release at the inflammatory corneal tissue. In vivo experiments on a mice model demonstrated that the multifunctional polymer vesicles achieved efficient treatment of BK, owing to the enhanced corneal adhesion and penetration, bacteria targeting, ROS-triggered CIP release, and the combined antioxidant-antibiotic therapy. This synergistic strategy holds great potential in the treatment of BK and other diseases associated with bacterial infections.
Asunto(s)
Infecciones Bacterianas del Ojo , Queratitis , Animales , Ratones , Antioxidantes/farmacología , Polímeros/química , Especies Reactivas de Oxígeno , Queratitis/tratamiento farmacológico , Queratitis/microbiología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Ciprofloxacina , Infecciones Bacterianas del Ojo/tratamiento farmacológico , Infecciones Bacterianas del Ojo/microbiologíaRESUMEN
A lipid named DCPA was synthesized under microwave-assisted heating. DCPA possesses a pyridine betaine, hydrophilic group that can be complexed with water through hydrogen bonding (DCPA-H2 O). DCPA-H2 O liposomes became protonated relatively fast already at pH<6.8, due to the high HOMO binding energy of DCPA-H2 O. In murine models, DCPA-H2 O liposomes had longer blood circulation times than natural DPPC or cationic DCPM liposomes, while after tail-vein injection DCPA-H2 O liposomes targeted faster to solid tumors and intra-abdominal infectious biofilms. Therapeutic efficacy in a murine, infected wound-healing model of tail-vein injected ciprofloxacin-loaded DCPA-H2 O liposomes exceeded the ones of clinically applied ciprofloxacin as well as of ciprofloxacin-loaded DPPC or DCPM liposomes.
Asunto(s)
Portadores de Fármacos/farmacocinética , Liposomas/farmacocinética , Neoplasias/diagnóstico por imagen , Infecciones Estafilocócicas/diagnóstico por imagen , Agua/química , Acetatos/síntesis química , Acetatos/farmacocinética , Animales , Antibacterianos/uso terapéutico , Biopelículas , Ciprofloxacina/uso terapéutico , Portadores de Fármacos/síntesis química , Femenino , Colorantes Fluorescentes/química , Células Hep G2 , Humanos , Concentración de Iones de Hidrógeno , Liposomas/química , Masculino , Ratones Endogámicos BALB C , Mycobacterium tuberculosis/fisiología , Compuestos de Piridinio/síntesis química , Compuestos de Piridinio/farmacocinética , Ratas Sprague-Dawley , Rodaminas/química , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/fisiopatología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Tuberculosis/diagnóstico por imagen , Tuberculosis/fisiopatologíaRESUMEN
While poly(acyclic orthoester)s (PAOEs) have many appealing features for drug delivery, their application is significantly hindered by a lack of facile synthetic methods. Reported here is a simple method for synthesizing acyclic diketene acetal monomers from diols and vinyl ether, and their polymerization with a diol to first synthesize PAOEs. The PAOEs rapidly hydrolyze at lysosomal pH. With the help of a cationic lipid, ovalbumin, a model vaccine antigen was efficiently loaded into PAOEs nanoparticles using a double emulsion method. These nanoparticles efficiently delivered ovalbumin into the cytosol of dendritic cells and demonstrated enhanced antigen presentation over poly(lactic-co-glycolic acid) (PLGA) nanoparticles. PAOEs are promising vehicles for intracellular delivery of biopharmaceuticals and could increase the utility of poly(orthoesters) in biomedical research.
Asunto(s)
Materiales Biocompatibles/síntesis química , Ovalbúmina/inmunología , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/inmunología , Vacunas/inmunología , Presentación de Antígeno/inmunología , Materiales Biocompatibles/química , Citosol/química , Citosol/inmunología , Estructura Molecular , Nanopartículas/química , Ovalbúmina/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/síntesis química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Vacunas/químicaRESUMEN
The formation of a protein corona on nanoprobes in the blood can not only reduce the delivery efficiency to their destination but also inhibit the functions of the nanoprobes. Herein, we report a multifunctional nanogel that can shield a single gold nanoparticle (AuNP) probe from interaction with the serum proteins, virtually eliminating protein corona formation on the nanoprobes. As a result, the delivery efficiency of the nanogel-encapsulated nanoprobes to tumors was dramatically enhanced. When the probes are delivered into target cells, the nanogel shells are degraded in acidic endosomes, where a proton sponge effect occurs instantaneously to release the AuNP probes into the cytoplasm to realize their bioimaging functions. We demonstrated the applicability of these probes for high-fidelity, noninvasive imaging of caspase activity in both cancer cells and in tumors. This strategy offers an exciting opportunity to design high-efficacy nanoprobes for in vivo imaging.
Asunto(s)
Caspasas/metabolismo , Nanopartículas del Metal/química , Sondas Moleculares/química , Nanogeles/química , Composición de Medicamentos , Oro/química , Células HeLa , Humanos , Macrófagos/metabolismo , Corona de Proteínas/químicaRESUMEN
With expanding applications of hydrogels in diverse fields ranging from biomaterials to sensors, actuators, and soft robotics, there is an urgent need to endow one single gel with multiple physicochemical properties, such as stimuli-responsiveness, injectability, self-healing, and tunable internal structures. However, it is challenging to simultaneously incorporate these highly sought-after properties into one single gel. Herein, a conceptual hydrogel system with all of these properties is presented via combining bioconjugate chemistry, filamentous viruses, and dynamic covalent bonds. Nanofilamentous bioconjugates with diol affinity were prepared by coupling a tailor-synthesized low-p Ka phenylboronic acid (PBA) derivative to a well-defined green nanofiber the M13 virus with a high aspect ratio (PBA-M13). Dynamic hydrogels with tunable mechanical strength were prepared by using multiple diol-containing agents such as poly(vinyl alcohol) to cross-link such PBA-M13 via the classic boronic-diol dynamic bonds. The as-prepared hydrogels exhibit excellent injectability and self-healing behaviors as well as easy chemical accessibility of the PBA moieties on the virus backbone inside the gel matrix. Ordered internal structures were imparted into virus-based hydrogels by simple shear-induced alignment of the virus nanofibers. Furthermore, unique hydrogels with chiral internal structures were fabricated through in situ gelation induced by diffusion of diol-containing molecules to fix the chiral liquid crystal phase of the PBA-M13 virus. Sugar responsiveness of this gel leads to a glucose-regulated release behavior of payloads such as insulin. All of these properties have been implemented at physiological pH, which will facilitate future applications of these hydrogels as biomaterials.
Asunto(s)
Bacteriófago M13/química , Glucosa/metabolismo , Hidrogeles/química , Nanofibras/química , Ácidos Borónicos/química , Concentración de Iones de Hidrógeno , Inyecciones , Insulina/metabolismo , Cristales Líquidos/química , Modelos Moleculares , Conformación Molecular , Alcohol Polivinílico/químicaRESUMEN
Insulin plays a significant role in diabetes treatment. Although a huge number of insulin-loaded, glucose-responsive nanocarriers have been developed in past decades, most of them showed a lower loading capacity and efficiency due to the weak interaction between insulin and nanocarriers. In this work, a novel insulin-encapsulated glucose-responsive polymeric complex micelle (CM) is devised, showing (i) enhanced insulin-loading efficiency owing to the zinc ions' chelation by nitrilotriacetic acid (NTA) groups of NTA-functioned glycopolymer and the histidine imidazole of insulin, (ii) the glucose-triggered pulse release of insulin, and (iii) long stability under physiological conditions. This CM was fabricated by the self-assembly of block copolymer PEG- b-P(Asp- co-AspPBA) and glycopolymer P(Asp- co-AspGA- co-AspNTA), resulting in complex micelles with a PEG shell and a cross-linked core composed of phenylboronic acid (PBA)/glucose complexations. Notably, the modified nitrilotriacetic acid (NTA) groups of CM could specifically bind insulin via chelated zinc ions, thus enhancing the loading efficacy of insulin compared to that of nonmodified CM. The dynamic PBA/glucose complexation core of CM dissociates under the trigger of high glucose concentration (>2 g/L) while being quite stable in low glucose concentrations (<2 g/L), as demonstrated by the pulse release of insulin in vitro. Finally, in a murine model of type 1 diabetes, NTA-modified complex micelles loading an insulin (NTA-CM-INS) group exhibited a long hypoglycemic effect which is superior to that of free insulin in the PBS (PBS-INS) group and insulin-loaded complex micelles without an NTA modification (CM-INS) group. This long-term effect benefited from Zn(II) chelation by NTA-modified complex micelles and could avoid hypoglycemia caused by the burst release of insulin. Taken together, this constitutes a highly effective way to encapsulate insulin and release insulin via an on-demand manner for blood glucose control in diabetes.
Asunto(s)
Diabetes Mellitus Tipo 1/tratamiento farmacológico , Portadores de Fármacos/química , Glucosa/química , Insulina/uso terapéutico , Micelas , Ácido Nitrilotriacético/química , Animales , Ácidos Borónicos/síntesis química , Ácidos Borónicos/química , Ácidos Borónicos/toxicidad , Quelantes/síntesis química , Quelantes/química , Quelantes/toxicidad , Portadores de Fármacos/síntesis química , Portadores de Fármacos/toxicidad , Liberación de Fármacos , Ratones , Células 3T3 NIH , Ácido Nitrilotriacético/síntesis química , Ácido Nitrilotriacético/toxicidad , Péptidos/síntesis química , Péptidos/química , Péptidos/toxicidad , Polietilenglicoles/síntesis química , Polietilenglicoles/química , Polietilenglicoles/toxicidad , Zinc/químicaRESUMEN
Inadvertent photosensitizer-activation and singlet-oxygen generation hampers clinical application of photodynamic therapies of superficial tumors or subcutaneous infections. Therefore, a reversible photoswitchable system was designed in micellar nanocarriers using ZnTPP as a photosensitizer and BDTE as a photoswitch. Singlet-oxygen generation upon irradiation didnot occur in closed-switch micelles with ZnTPP/BDTE feeding ratios >1:10. Deliberate switch closure/opening within 65-80 min was possible through thin layers of porcine tissue in vitro, increasing for thicker layers. Inadvertent opening of the switch by simulated daylight, took several tens of hours. Creating deliberate cell damage and prevention of inadvertent damage in vitro and in mice could be done at lower ZnTPP/BDTE feeding ratios (1:5) in open-switch micelles and at higher irradiation intensities than inferred from chemical clues to generate singlet-oxygen. The reduction of inadvertent photosensitizer activation in micellar nanocarriers, while maintaining the ability to kill tumor cells and infectious bacteria established here, brings photodynamic therapies closer to clinical application.
Asunto(s)
Nanoestructuras/química , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacología , Oxígeno Singlete/metabolismo , Células 3T3 , Animales , Portadores de Fármacos/química , Portadores de Fármacos/farmacología , Espectroscopía de Resonancia por Spin del Electrón , Femenino , Células HeLa , Humanos , Lactonas/química , Ratones , Ratones Endogámicos BALB C , Micelas , Fármacos Fotosensibilizantes/administración & dosificación , Polietilenglicoles/química , Porfirinas/química , Oxígeno Singlete/química , Espectrofotometría Ultravioleta , Zinc/químicaAsunto(s)
Academias e Institutos , Aniversarios y Eventos Especiales , Humanos , Polímeros , Universidades , Química OrgánicaRESUMEN
Molecular chaperones can elegantly fine-tune its hydrophobic/hydrophilic balance to assist a broad spectrum of nascent polypeptide chains to fold properly. Such precious property is difficult to be achieved by chaperone mimicking materials due to limited control of their surface characteristics that dictate interactions with unfolded protein intermediates. Mixed shell polymeric micelles (MSPMs), which consist of two kinds of dissimilar polymeric chains in the micellar shell, offer a convenient way to fine-tune surface properties of polymeric nanoparticles. In the current work, we have fabricated ca. 30 kinds of MSPMs with finely tunable hydrophilic/hydrophobic surface properties. We investigated the respective roles of thermosensitive and hydrophilic polymeric chains in the thermodenaturation protection of proteins down to the molecular structure. Although the three kinds of thermosensitive polymers investigated herein can form collapsed hydrophobic domains on the micellar surface, we found distinct capability to capture and release unfolded protein intermediates, due to their respective affinity for proteins. Meanwhile, in terms of the hydrophilic polymeric chains in the micellar shell, poly(ethylene glycol) (PEG) excels in assisting unfolded protein intermediates to refold properly via interacting with the refolding intermediates, resulting in enhanced chaperone efficiency. However, another hydrophilic polymer-poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) severely deteriorates the chaperone efficiency of MSPMs, due to its protein-resistant properties. Judicious combination of thermosensitive and hydrophilic chains in the micellar shell lead to MSPM-based artificial chaperones with optimal efficacy.
Asunto(s)
Micelas , Fosforilcolina/análogos & derivados , Ácidos Polimetacrílicos/química , Desnaturalización Proteica , Replegamiento Proteico , Materiales Biomiméticos , Anhidrasa Carbónica I/química , Dicroismo Circular , Dispersión Dinámica de Luz , Glicoles de Etileno/síntesis química , Glicoles de Etileno/química , Interacciones Hidrofóbicas e Hidrofílicas , Microscopía Electrónica de Transmisión , Fosforilcolina/síntesis química , Fosforilcolina/química , Poliésteres/síntesis química , Poliésteres/química , Propiedades de Superficie , TemperaturaRESUMEN
In the past decades, polymer based nanoscale polymeric assemblies have attracted continuous interest due to their potential applications in many fields, such as nanomedicine. Many efforts have been dedicated to tailoring the three-dimensional architecture and the placement of functional groups at well-defined positions within the polymeric assemblies, aiming to augment their function. To achieve such goals, in one way, novel polymeric building blocks can be designed by controlled living polymerization methodology and advanced chemical modifications. In contrast, by focusing on the end function, others and we have been practicing strategies of cooperative self-assembly of multiple polymeric building blocks chosen from the vast library of conventional block polymers which are easily available. The advantages of such strategies lie in the simplicity of the preparation process and versatile choice of the constituent polymers in terms of their chemical structure and functionality as well as the fact that cooperative self-assembly based on supramolecular interactions offers elegant and energy-efficient bottom-up strategies. Combination of these principles has been exploited to optimize the architecture of polymeric assemblies with improved function, to impart new functionality into micelles and to realize polymeric nanocomplexes exhibiting functional integration, similar to some natural systems like artificial viruses, molecular chaperones, multiple enzyme systems, and so forth. In this Account, we shall first summarize several straightforward designing principles with which cooperative assembly of multiple polymeric building blocks can be implemented, aiming to construct polymeric nanoassemblies with hierarchal structure and enhanced functionalities. Next, examples will be discussed to demonstrate the possibility to create multifunctional nanoparticles by combination of the designing principles and judiciously choosing of the building blocks. We focus on multifunctional nanoparticles which can partially address challenges widely existing in nanomedicine such as long blood circulation, efficient cellular uptake, and controllable release of payloads. Finally, bioactive polymeric assemblies, which have certain functions closely mimicking those of some natural systems, will be used to conceive the concept of functional integration.
Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Sustancias Macromoleculares/química , Nanopartículas/química , Polímeros/química , Materiales Biomiméticos , Micelas , Chaperonas Moleculares/química , Permeabilidad , Polímeros/síntesis química , Propiedades de SuperficieRESUMEN
Polymeric nanoparticles with glucose-responsiveness are of great interest in developing a self-regulated drug delivery system. In this work, glucose-responsive polymer vesicles were fabricated based on the complexation between a glucosamine (GA)-containing block copolymer PEG45-b-P(Asp-co-AspGA) and a phenylboronic acid (PBA)-containing block copolymer PEG114-b-P(Asp-co-AspPBA) with α-CD/PEG45 inclusion complex as the sacrificial template. The obtained polymer vesicles composed of cross-linked P(Asp-co-AspGA)/P(Asp-co-AspPBA) layer as wall and PEG chains as both inner and outer coronas. The vesicular morphology was observed by transmission electron microscopy (TEM), and the glucose-responsiveness was investigated by monitoring the variations of hydrodynamic diameter (Dh) and light scattering intensity (LSI) in the polymer vesicle solution with glucose using dynamic light scattering (DLS). Vancomycin as a model drug was encapsulated in the polymer vesicles and sugar-triggered drug release was carried out. This kind of polymer vesicle may be a promising candidate for glucose-responsive drug delivery.
Asunto(s)
Portadores de Fármacos/química , Glucosa/química , Nanopartículas/química , Polietilenglicoles/química , alfa-Ciclodextrinas/química , Antibacterianos/administración & dosificación , Antibacterianos/química , Ácido Aspártico/química , Ácidos Borónicos/química , Diálisis , Polietilenglicoles/síntesis química , Vancomicina/administración & dosificación , Vancomicina/química , alfa-Ciclodextrinas/síntesis químicaRESUMEN
Complexation between 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) and poly(ethylene glycol)-block-poly(L-lysine) (PEG-b-PLL) was performed via electrostatic interaction. Two kinds of primary arrays of TPPS with different supramolecular chirality induced by PLL were obtained in the resultant complex by inverting the mixing procedure of the two components. These arrays could be displaced by poly(sodium-p-styrenesulfonate) (PSS) from the chiral PLL template through competitive electrostatic complexation, and then PSS formed a polyion complex micelle with PEG-b-PLL. The template-removed TPPS arrays preserved their induced chirality and served as primary subunits for the secondary aggregation of TPPS. The morphology of the secondary aggregates was strongly dependent upon the asymmetric primary supramolecular arrangement of TPPS. The rodlike nanostructure that was â¼200 nm in length was composed of the primary arrays that showed opposite exciton chirality between the J- and H-bands. In contrast, the micrometer-sized fibrils observed were composed of the arrays with the same exciton chirality at the J- and H-bands.
Asunto(s)
Polietilenglicoles/química , Porfirinas/química , EstereoisomerismoRESUMEN
Exploring ideal nanocarriers for drug delivery systems has encountered unavoidable hurdles, especially the conflict between enhanced cellular uptake and prolonged blood circulation, which have determined the final efficacy of cancer therapy. Here, based on controlled self-assembly, surface structure variation in response to external environment was constructed toward overcoming the conflict. A novel micelle with mixed shell of hydrophilic poly(ethylene glycol) PEG and pH responsive hydrophobic poly(ß-amino ester) (PAE) was designed through the self-assembly of diblock amphiphilic copolymers. To avoid the accelerated clearance from blood circulation caused by the surface exposed targeting group c(RGDfK), here c(RGDfK) was conjugated to the hydrophobic PAE and hidden in the shell of PEG at pH 7.4. At tumor pH, charge conversion occurred, and c(RGDfK) stretched out of the shell, leading to facilitated cellular internalization according to the HepG2 cell uptake experiments. Meanwhile, the heterogeneous surface structure endowed the micelle with prolonged blood circulation. With the self-regulated multifunctional collaborated properties of enhanced cellular uptake and prolonged blood circulation, successful inhibition of tumor growth was achieved from the demonstration in a tumor-bearing mice model. This novel nanocarrier could be a promising candidate in future clinical experiments.
Asunto(s)
Antineoplásicos/química , Portadores de Fármacos/química , Nanopartículas/química , Animales , Línea Celular Tumoral , Sistemas de Liberación de Medicamentos/métodos , Femenino , Células Hep G2 , Humanos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Micelas , Polietilenglicoles/química , Polímeros/químicaRESUMEN
Polyamidoamine (PAMAM) dendrimers have been widely used as drug carriers, non-viral gene vectors and imaging agents. However, the use of dendrimers in biological system is constrained because of inherent toxicity and organ accumulation. In this study, the strategy of acetylation and PEGylation-acetylation was used to minimize PAMAM dendrimers toxicities and to improve their biodistribution and pharmacokinetics for medical application. PEGylated-acetylated PAMAM (G4-Ac-PEG) dendrimers were synthesized by PEGylation of acetylated PAMAM dendrimer of generation 4 (G4) with acetic anhydride and polyethylene glycol (PEG) 3.4 k. To investigate the cytotoxicity and in vivo biodistribution of the conjugates, in vitro cell viability analysis, Iodine-125 (125I) imaging, tissue distribution and hematoxylin-eosin (HE) staining were performed. We find that acetylation and PEGylation-acetylation essentially eliminates the inherent dendrimer cytotoxicity in vitro. Planar gamma (gamma) camera imaging revealed that all the conjugates were slowly eliminated from the body, and higher abdominal accumulation of acetylation PAMAM dendrimer was observed. Tissue distribution analysis showed that PEGylated-acetylated dendrimers have longer blood retention and lower accumulation in organs such as the kidney and liver than the non-PEGylated-acetylated dendrimers, but acetylation only can significantly increase the accumulation of G4 in the kidney and decrease the concentration in blood. Histology results reveal that no obvious damage was observed in all groups after high dose administration. This study indicates that PEGylation-acetylation could improve the blood retention, decrease organ accumulation, and improve pharmacokinetic profile, which suggests that PEGylation-acetylation provides an alternative method for PAMAM dendrimers modification.
Asunto(s)
Dendrímeros/síntesis química , Dendrímeros/farmacocinética , Polietilenglicoles/química , Acetilación , Animales , Dendrímeros/administración & dosificación , Células HEK293 , Humanos , Infusiones Intravenosas , Radioisótopos de Yodo/administración & dosificación , Masculino , Ratones , Ratones Endogámicos BALB C , Distribución TisularRESUMEN
The disruption of Aß homeostasis, which results in the accumulation of neurotoxic amyloids, is the fundamental cause of Alzheimer's disease (AD). Molecular chaperones play a critical role in controlling undesired protein misfolding and maintaining intricate proteostasis inâ vivo. Inspired by a natural molecular chaperone, an artificial chaperone consisting of mixed-shell polymeric micelles (MSPMs) has been devised with tunable surface properties, serving as a suppressor of AD. Taking advantage of biocompatibility, selectivity toward aberrant proteins, and long blood circulation, these MSPM-based chaperones can maintain Aß homeostasis by a combination of inhibiting Aß fibrillation and facilitating Aß aggregate clearance and simultaneously reducing Aß-mediated neurotoxicity. The balance of hydrophilic/hydrophobic moieties on the surface of MSPMs is important for their enhanced therapeutic effect.
Asunto(s)
Péptidos beta-Amiloides/química , Homeostasis , Micelas , Chaperonas Moleculares/química , Polímeros/química , Dicroismo Circular , Cinética , Microscopía Electrónica de Transmisión , Espectrofotometría UltravioletaRESUMEN
Chronic wound treatment has emerged as a significant healthcare concern worldwide due to its substantial economic burden and the limited effectiveness of current treatments. Effective management of biofilm infections, regulation of excessive oxidative stress, and promotion of tissue regeneration are crucial for addressing chronic wounds. Hydrogel stands out as a promising candidate for chronic wound treatment. However, its clinical application is hindered by the difficulty in designing and fabricating easily and conveniently. To overcome these obstacles, we present a supermolecular G-quadruplex hydrogel with the desired multifunction via a dynamic covalent strategy and Hoogsteen-type hydrogen bonding. The G-quadruplex hydrogel is made from the self-assembly of guanosine, 2-formylphenyboronic acid, polyethylenimine, and potassium chloride, employing dynamic covalent strategy and Hoogsteen-type hydrogen bonding. In the acidic/oxidative microenvironment associated with bacterial infections, the hydrogel undergoes controlled degradation, releasing the polyethylenimine domain, which effectively eliminates bacteria. Furthermore, nanocomplexes comprising guanosine monophosphate and manganese sulfate are incorporated into the hydrogel skeleton, endowing it with the ability to scavenge reactive oxygen species and modulate macrophages. Additionally, the integration of basic fibroblast growth factor into the G-quadruplex skeleton through dynamic covalent bonds facilitates controlled tissue regeneration. In summary, the facile preparation process and the incorporation of multiple functionalities render the G-quadruplex hydrogel a highly promising candidate for advanced wound dressing. It holds great potential to transition from laboratory research to clinical practice, addressing the pressing needs of chronic wound management.
Asunto(s)
Sordera , Hidrogeles , Humanos , Polietileneimina , Vendajes , Antibacterianos/farmacología , BiopelículasRESUMEN
Photothermal therapy (PTT) has emerged as a promising approach for treating bacterial infections. However, achieving a high photothermal conversion efficiency (PCE) of photothermal agents (PTAs) remains a challenge. Such a problem is usually compensated by the use of a high-intensity laser, which inevitably causes tissue damage. Here, we present a universal strategy to enhance PCE by regulating the molecular aggregation states of PTAs within thermoresponsive nanogels. We demonstrate the effectiveness of this approach using aggregation-induced emission (AIE) and aggregation-caused quenching (ACQ) PTAs, showing significant enhancements in PCE without the need for intricate molecular modifications. Notably, the highest PCEs reach up to 80.9% and 64.4% for AIE-NG and ACQ-NG, respectively, which are nearly 2-fold of their self-aggregate counterparts. Moreover, we elucidate the mechanism underlying PCE enhancement, highlighting the role of strong intermolecular π-π interactions facilitated by nanogel-induced volume contraction. Furthermore, we validate the safety and efficacy of this strategy in in vitro and in vivo models of bacterial infections at safe laser power densities, demonstrating its potential for clinical translation. Our findings offer a straightforward, universal, and versatile method to improve PTT outcomes while minimizing cytotoxicity, paving the way for enhanced treatment of bacterial infections with safe PTT protocols.
Asunto(s)
Terapia Fototérmica , Animales , Ratones , Humanos , Infecciones Bacterianas/terapia , Nanogeles/químicaRESUMEN
Biomaterial-associated infection (BAI) is considered a unique infection due to the presence of a biomaterial yielding frustrated immune-cells, ineffective in clearing local micro-organisms. The involvement of surface-adherent/surface-adapted micro-organisms in BAI, logically points to biomaterial surface-modifications for BAI-control. Biomaterial surface-modification is most suitable for prevention before adhering bacteria have grown into a mature biofilm, while BAI-treatment is virtually impossible through surface-modification. Hundreds of different surface-modifications have been proposed for BAI-control but few have passed clinical trials due to the statistical near-impossibility of benefit-demonstration. Yet, no biomaterial surface-modification forwarded, is clinically embraced. Collectively, this leads us to conclude that surface-modification is a dead-end road. Accepting that BAI is, like most human infections, due to surface-adherent biofilms (though not always to a foreign material), and regarding BAI as a common infection, opens a more-generally-applicable and therewith easier-to-validate road. Pre-clinical models have shown that stimuli-responsive nano-antimicrobials and antibiotic-loaded nanocarriers exhibit prolonged blood-circulation times and can respond to a biofilm's micro-environment to penetrate and accumulate within biofilms, prompt ROS-generation and synergistic killing with antibiotics of antibiotic-resistant pathogens without inducing further antimicrobial-resistance. Moreover, they can boost frustrated immune-cells around a biomaterial reducing the importance of this unique BAI-feature. Time to start exploring the nano-road for BAI-control.
Asunto(s)
Materiales Biocompatibles , Biopelículas , Nanotecnología , Propiedades de Superficie , Animales , Humanos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Materiales Biocompatibles/química , Biopelículas/efectos de los fármacos , Nanotecnología/métodos , Prótesis e Implantes , Infecciones Relacionadas con Prótesis/prevención & controlRESUMEN
We have fabricated a mixed-shell polymeric micelle (MSPM) that closely mimics the natural molecular chaperone GroEL-GroES complex in terms of structure and functionality. This MSPM, which possesses a shared PLA core and a homogeneously mixed PEG and PNIAPM shell, is constructed through the co-assembly of block copolymers poly(lactide-b-poly(ethylene oxide) (PLA-b-PEG) and poly(lactide)-b-poly(N-isopropylacryamide) (PLA-b-PNIPAM). Above the lower critical solution temperature (LCST) of PNIPAM, the MSPM evolves into a core-shell-corona micelle (CSCM), as a functional state with hydrophobic PNIPAM domains on its surface. Light scattering (LS), TEM, and fluorescence and circular dichroism (CD) spectroscopy were performed to investigate the working mechanism of the chaperone-like behavior of this system. Unfolded protein intermediates are captured by the hydrophobic PNIPAM domains of the CSCM, which prevent harmful protein aggregation. During cooling, PNIPAM reverts into its hydrophilic state, thereby inducing the release of the bound unfolded proteins. The refolding process of the released proteins is spontaneously accomplished by the presence of PEG in the mixed shell. Carbonic anhydraseâ B (CAB) was chosen as a model to investigate the refolding efficiency of the released proteins. In the presence of MSPM, almost 93 % CAB activity was recovered during cooling after complete denaturation at 70 °C. Further results reveal that this MSPM also works with a wide spectrum of proteins with more-complicated structures, including some multimeric proteins. Given the convenience and generality in preventing the thermal aggregation of proteins, this MSPM-based chaperone might be useful for preventing the toxic aggregation of misfolded proteins in some diseases.