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Nanocarriers based on cationic materials play a central role in the success of mRNA-based therapies. Traditionally, amine-bearing lipids and polymers have been successfully employed for creating mRNA-loaded nanocarriers, though they still present challenges, such as physical and biological instability, limiting both delivery efficiency and therapeutic potential. Non-amine cations could be a promising avenue in addressing these limitations. However, such alternatives remain notably underexplored. Herein, we introduced triphenylphosphonium (TPP) as an alternative cationic moiety for mRNA delivery, leveraging its advantageous properties for nucleic acid complexation. Through the modification of amine-bearing catiomers, we replaced traditional amine-based counterparts with TPP to create innovative polymeric micelles as mRNA nanocarriers. A comprehensive analysis, encompassing physicochemical, thermodynamic, and computational approaches, revealed that the TPP substitution significantly influenced polymer self-assembly, mRNA binding, and the overall stability of mRNA-loaded polymeric micelles. Upon intravenous injection, TPP-bearing micelles demonstrated a remarkable increase in mRNA bioavailability, facilitating efficient protein production in solid tumors. These findings provide a compelling rationale for substituting amines with TPP, emphasizing their potential for advancing mRNA therapeutics.
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Bismuth (Bi(III)) substitution in hydroxyapatite (HAp) lattice confers unique properties such as antibacterial, catalytic, radiosensitization, and conductive properties while preserving the innate bioactivity. Understanding the local structural changes upon Bi3+ substitution is essential for controlling the stability and optimizing the properties of HAp. Despite numerous experimental studies, the precise substitution behaviors, such as site preference and structural stability, remain incompletely understood. In this study, the substitution behavior of Bi(III) into the HAp lattice with formula of Ca9Bi(PO4)6(O)(OH) was investigated via first-principles simulation by implementing density functional theory. Energy calculations showed that Bi3+ preferentially occupies the Ca(2) site with an energy difference of â¼0.02 eV per atom. Local structure analysis revealed higher bond population values and an oxygen coordination shift from 7 to 6 for the Ca(2) site, attributed to the greater covalent interactions and its flexible environment accommodating the bulky Bi3+ ion and its stereochemically active lone pair. This work provides the first comprehensive investigation on Bi3+ ion substitution site preference in HAp using first-principles simulations.
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Early and accurate cancer diagnosis is crucial for improving patient survival rates. Luminescent nanoparticles have emerged as a promising tool in fluorescence bioimaging for cancer diagnosis. To enhance diagnostic accuracy, ligands promoting endocytosis into cancer cells are commonly incorporated onto nanoparticle surfaces. Folic acid (FA) is one such ligand, known to specifically bind to folate receptors (FR) overexpressed in various cancer cells such as cervical and ovarian carcinoma. Therefore, surface modification of luminescent nanoparticles with FA can enhance both luminescence efficiency and diagnostic accuracy. In this study, luminescent europium-doped hydroxyapatite (EuHAp) nanocrystals were prepared via hydrothermal method and subsequently modified with (3-Aminopropyl)triethoxysilane (APTES) followed by FA to target FR-positive human cervical adenocarcinoma cell line (HeLa) cells. The sequential grafting of APTES and then FA formed a robust covalent linkage between the nanocrystals and FA. Rod-shaped FA-modified EuHAp nanocrystals, approximately 100â¯nm in size, exhibited emission peaks at 589, 615, and 650â¯nm upon excitation at 397â¯nm. Despite a reduction in photoluminescence intensity following FA modification, fluorescence microscopy revealed a remarkable 120-fold increase in intensity compared to unmodified EuHAp, attributed to the enhanced uptake of FA-modified EuHAp. Additionally, confocal microscope observations confirmed the specificity and the internalization of FA-modified EuHAp nanocrystals in HeLa cells. In conclusion, the modification of EuHAp nanocrystals with FA presents a promising strategy to enhance the diagnostic potential of cancer bioimaging probes.
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Durapatita , Europio , Ácido Fólico , Nanopartículas , Humanos , Ácido Fólico/química , Europio/química , Nanopartículas/química , Células HeLa , Durapatita/química , Luminiscencia , Microscopía Fluorescente , Propilaminas/química , Tamaño de la Partícula , Sustancias Luminiscentes/químicaRESUMEN
Multi-arm star-shaped block copolymers with precisely tuned nano-architectures are promising candidates for drug delivery. Herein, we developed 4- and 6-arm star-shaped block copolymers consisting of poly(furfuryl glycidol) (PFG) as the core-forming segments and biocompatible poly(ethylene glycol) (PEG) as the shell-forming blocks. The polymerization degree of each block was controlled by adjusting the feeding ratio of a furfuryl glycidyl ether and ethylene oxide. The size of the series of block copolymers was found to be less than 10 nm in DMF. In water, the polymers showed sizes larger than 20 nm, which can be related to the association of the polymers. The star-shaped block copolymers effectively loaded maleimide-bearing model drugs in their core-forming segment with the Diels-Alder reaction. These drugs were rapidly released upon heating via a retro Diels-Alder step. When the star-shaped block copolymers were injected intravenously in mice, they showed prolonged blood circulation, with more than 80% of the injected dose remaining in the bloodstream at 6 h after intravenous injection. These results indicate the potential of the star-shaped PFG-PEG block copolymers as long-circulating nanocarriers.
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Cancer theranostics combines therapeutic and diagnostic capabilities into a single system to treat cancer efficiently. Biocompatible nanomaterials can be engineered to exhibit cancer theranostic functions, for instance radiosensitization and photoluminescence. In this study, trivalent Bi and Eu ions were co-substituted into the lattice of hydroxyapatite (Bi(III):Eu(III) HAp) to develop a cancer theranostic nanocrystal. Bi provides radiosensitization capabilities while Eu imparts photoluminescence properties. To complement the radiotherapeutic function, l-buthionine sulfoximine (l-BSO) was adsorbed onto the nanocrystal surface. l-BSO inhibits the biosynthesis of cellular antioxidants, which can enhance radiosensitization effects. The Bi(III):Eu(III) HAp nanocrystals were prepared via a hydrothermal method. Structural and compositional analyses showed that both Bi and Eu ions were substituted into the HAp lattice. l-BSO was adsorbed onto the surface via electrostatic interactions between the charged carboxyl and amino groups of l-BSO and the surface ions of the nanocrystals. The adsorption followed the Langmuir isotherm model, implying a homogeneous monolayer adsorption. The l-BSO adsorbed Bi(III):Eu(III) HAp nanocrystals were found to have negligible cytotoxicity except the setting with l-BSO adsorbed amounts of 0.44 µmol/m2. This l-BSO amount was found to be high enough to elicit cytotoxicity due to l-BSO being released and causing excessive antioxidant depletion. Gamma ray irradiation clearly activated the cytotoxicity of the samples and increased the cell death rate, confirming radiosensitization abilities. At a constant amount of nanocrystals, the cell death rate increases with l-BSO concentration. This indicates that l-BSO can enhance the radiosensitization effect of the Bi(III):Eu(III) HAp nanocrystals.
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Nanopartículas , Neoplasias , Humanos , Butionina Sulfoximina , Metionina Sulfoximina/farmacología , Metionina Sulfoximina/uso terapéutico , Durapatita/farmacología , Adsorción , Neoplasias/tratamiento farmacológico , Iones , Glutatión/metabolismoRESUMEN
Medulloblastoma is a life-threatening disease with poor therapeutic outcomes. In chemotherapy, low drug accumulation has been a cause of these outcomes. Such inadequate response to treatments has been associated with low drug accumulation, particularly with a limited cellular uptake of drugs. Recently, the conjugation of drugs to ligand molecules with high affinity to tumor cells has attracted much attention for enhancing drug internalization into target cells. Moreover, combining tumor-targeting ligands with nano-scaled drug carriers can potentially improve drug loading capacity and the versatility of the delivery. Herein, we focused on the possibility of targeting CD276/B7-H3, which is highly expressed on the medulloblastoma cell membrane, as a strategy for enhancing the cellular uptake of ligand-installed nanocarriers. Thus, anti-CD276 antibodies were conjugated on the surface of model nanocarriers based on polyion complex micelles (PIC/m) via click chemistry. The results showed that the anti-CD276 antibody-installed PIC/m improved intracellular delivery into CD276-expressing medulloblastoma cells in a CD276-dependent manner. Moreover, increasing the number of antibodies on the surface of micelles improved the cellular uptake efficiency. These observations indicate the potential of anti-CD276 antibody-installed nanocarriers for promoting drug delivery in medulloblastoma.
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Mesoscopic-sized polyion complex vesicles (PICsomes) with semi-permeable membranes are promising nanoreactors for enzyme prodrug therapy (EPT), mainly due to their ability to accommodate enzymes in their inner cavity. Increased loading efficacy and retained activity of enzymes in PICsomes are crucial for their practical application. Herein, a novel preparation method for enzyme-loaded PICsomes, the stepwise crosslinking (SWCL) method, was developed to achieve both high feed-to-loading enzyme efficiency and high enzymatic activity under in vivo conditions. Cytosine deaminase (CD), which catalyzes the conversion of the 5-fluorocytosine (5-FC) prodrug to cytotoxic 5-fluorouracil (5-FU), was loaded into PICsomes. The SWCL strategy enabled a substantial increase in CD encapsulation efficiency, up to ~44% of the feeding amount. CD-loaded PICsomes (CD@PICsomes) showed prolonged blood circulation to achieve appreciable tumor accumulation via enhanced permeability and retention effect. The combination of CD@PICsomes and 5-FC produced superior antitumor activity in a subcutaneous model of C26 murine colon adenocarcinoma, even at a lower dose than systemic 5-FU treatment, and showed significantly reduced adverse effects. These results reveal the feasibility of PICsome-based EPT as a novel, highly efficient, and safe cancer treatment modality.
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BACKGROUND: Although a large amount of evidence has revealed that amyloid ß (Aß), especially Aß oligomers, protofibrils, and pyroglutamated Aßs, participate primarily in the pathophysiological processes of Alzheimer's disease, most clinical trials of anti-Aß antibody therapy have never acquired successful efficacy in human clinical trials, partly because peripheral administration of antibody medications was unable to deliver sufficient amounts of the molecules to the brain. Recently, we developed polymeric nanomicelles capable of passing through the blood-brain barrier that function as chaperones to deliver larger amounts of heavy molecules to the brain. Herein, we aimed to evaluate the efficacy of newly developed antibody 6H4 fragments specific to Aß oligomers encapsulated in polymeric nanomicelles on the development of Alzheimer's disease pathology in Alzheimer's disease model mice at the age of emergence of early Alzheimer's disease pathology. RESULTS: During the 10-week administration of 6H4 antibody fragments in polymeric nanomicelles, a significant reduction in the amounts of various toxic Aß species, such as Aß oligomers, toxic Aß conformers, and pyroglutamated Aßs in the brain was observed. In addition, immunohistochemistry indicated inhibition of diameters of Aß plaques, Aß-antibody immunoreactive areas, and also plaque core formation. Behavioral analysis of the mice model revealed that the 6H4 fragments-polymeric nanomicelle group was significantly better at maintaining long-term spatial reference memory in the probe and platform tests of the water maze, thereby indicating inhibition of the pathophysiological process of Alzheimer's disease. CONCLUSIONS: The results indicated that the strategy of reducing toxic Aß species in early dementia owing to Alzheimer's disease by providing sufficient antibodies in the brain may modify Alzheimer's disease progression.
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Enfermedad de Alzheimer , Péptidos beta-Amiloides , Humanos , Animales , Ratones , Enfermedad de Alzheimer/tratamiento farmacológico , Encéfalo , Barrera Hematoencefálica , Anticuerpos , Placa Amiloide , PolímerosRESUMEN
Biological membranes are functionalized by membrane-associated protein machinery. Membrane-associated transport processes, such as endocytosis, represent a fundamental and universal function mediated by membrane-deforming protein machines, by which small biomolecules and even micrometer-size substances can be transported via encapsulation into membrane vesicles. Although synthetic molecules that induce dynamic membrane deformation have been reported, a molecular approach enabling membrane transport in which membrane deformation is coupled with substance binding and transport remains critically lacking. Here, we developed an amphiphilic molecular machine containing a photoresponsive diazocine core (AzoMEx) that localizes in a phospholipid membrane. Upon photoirradiation, AzoMEx expands the liposomal membrane to bias vesicles toward outside-in fission in the membrane deformation process. Cargo components, including micrometer-size M13 bacteriophages that interact with AzoMEx, are efficiently incorporated into the vesicles through the outside-in fission. Encapsulated M13 bacteriophages are transiently protected from the external environment and therefore retain biological activity during distribution throughout the body via the blood following administration. This research developed a molecular approach using synthetic molecular machinery for membrane functionalization to transport micrometer-size substances and objects via vesicle encapsulation. The molecular design demonstrated in this study to expand the membrane for deformation and binding to a cargo component can lead to the development of drug delivery materials and chemical tools for controlling cellular activities.
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Endocitosis , Proteínas de la Membrana , Membrana Celular/metabolismo , Proteínas de la Membrana/metabolismo , Liposomas/química , Transporte BiológicoRESUMEN
Coronary stenosis has been one of the most common heart diseases that drastically increases the risk of fatal disorders such as heart attack. Angioplasty using drug coated balloons (DCB) has been one of the most safe and promising treatments. To minimize the risk of thrombosis of such DCBs during intervention, a different approach that can secure high hemocompatibility under blood flow is necessary. Here we report a method of improving the photoresponsive platform's hemocompatibility by conjugating polyethylene glycol (PEG), onto the functional groups located at the balloon surface. In this study, latex microbeads were used as models for balloons to enable precise observation of its surface under microscopy. These beads were decorated with PEG polymers of a variety of lengths and grafting densities, along with the Cy5-Photoclevable (PC) linker conjugate to mimic drugs to be loaded onto the platform. Results showed that PEG length and grafting density are both critical factors that alter not only its hemocompatibility, but also the drug load and release efficiency of such platform. Thus, although further investigation is necessary to optimize the tradeoff between hemocompatibility, drug load, and release efficiency, it is safe to conclude that PEGylation of DCB surface is an effective method of enhancing and maintaining high hemocompatibility to minimize the risk of thrombosis during angioplasty.
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Angioplastia de Balón , Materiales Biocompatibles Revestidos , Liberación de Fármacos , Paclitaxel , Polietilenglicoles , Resultado del TratamientoRESUMEN
A metal-binding peptide appending cholic acid, Chol-MBP, formed bicelles by mixing with 1,2-dipalmitoyl-sn-glycero-3-phosphorylcholine (DPPC). Coordination of Chol-MBP with Cu2+ stabilized DPPC bicelles against dilution and contamination of serum proteins, enabling extended blood circulation. This study demonstrates an effective supramolecular design of phospholipid bicelles with enhanced stability useful for membrane-based biomaterials.
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Membrana Dobles de Lípidos , Fosfolípidos , Quelantes , Membrana Dobles de Lípidos/química , Péptidos , Fosfolípidos/química , FosforilcolinaRESUMEN
Prevention of metastatic and local-regional recurrence of cancer after surgery remains difficult. Targeting postsurgical premetastatic niche and microresiduals presents an excellent prospective opportunity but is often challenged by poor therapeutic delivery into minimal residual tumors. Here, an enzymatically transformable polymer-based nanotherapeutic approach is presented that exploits matrix metalloproteinase (MMP) overactivation in tumor-associated tissues to guide the codelivery of colchicine (microtubule-disrupting and anti-inflammatory agent) and marimastat (MMP inhibitor). The dePEGylation of polymersomes catalyzed by MMPs not only exposes the guanidine moiety to improve tissue/cell-targeting/retention to increase bioavailability, but also differentially releases marimastat and colchicine to engage their extracellular (MMPs) and intracellular (microtubules) targets of action, respectively. In primary tumors/overt metastases, the vasculature-specific targeting of nanotherapeutics can function synchronously with the enhanced permeability and retention effect to deter malignant progression of metastatic breast cancer. After the surgical removal of large primary tumors, nanotherapeutic agents are localized in the premetastatic niche and at the site of the postsurgical wound, disrupting the premetastatic microenvironment and eliminating microresiduals, which radically reduces metastatic and local-regional recurrence. The findings suggest that nanotherapeutics can safely widen the therapeutic window to resuscitate colchicine and MMP inhibitors for other inflammatory disorders.
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Neoplasias de la Mama , Nanomedicina , Neoplasias de la Mama/patología , Colchicina/uso terapéutico , Femenino , Humanos , Inhibidores de la Metaloproteinasa de la Matriz/uso terapéutico , Estudios Prospectivos , Microambiente TumoralRESUMEN
Because of the blood-tumour barrier and cross-reactivity with healthy tissues, immune checkpoint blockade therapy against glioblastoma has inadequate efficacy and is associated with a high risk of immune-related adverse events. Here we show that anti-programmed death-ligand 1 antibodies conjugated with multiple poly(ethylene glycol) (PEG) chains functionalized to target glucose transporter 1 (which is overexpressed in brain capillaries) and detaching in the reductive tumour microenvironment augment the potency and safety of checkpoint blockade therapy against glioblastoma. In mice bearing orthotopic glioblastoma tumours, a single dose of glucosylated and multi-PEGylated antibodies reinvigorated antitumour immune responses, induced immunological memory that protected the animals against rechallenge with tumour cells, and suppressed autoimmune responses in the animals' healthy tissues. Drug-delivery formulations leveraging multivalent ligand interactions and the properties of the tumour microenvironment to facilitate the crossing of blood-tumour barriers and increase drug specificity may enhance the efficacy and safety of other antibody-based therapies.
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Neoplasias Encefálicas , Glioblastoma , Animales , Encéfalo , Glioblastoma/tratamiento farmacológico , Ratones , Polímeros , Microambiente TumoralRESUMEN
Dynamic bursting in tumor vasculature has recently sparked interest as a novel particle transportation route for drug delivery. These bursts facilitate the transport of sub-100 nm nanoparticles into tumors, though their contribution on the access of other blood-borne particles remains unknown. To evaluate the versatility of this phenomenon, the in vivo kinetics of a variety of intravenously injected particles and their penetration in tumor xenografts and allografts are compared. Dextran, polymeric micelles, liposomes, and polymeric vesicles with diameters ranging from 32 to 302 nm are found to colocalize in virtually all vascular bursts. By mathematical modeling, the burst vent size is estimated to be 625 nm or larger, indicating the dynamic and stochastic formation of large permeation routes in tumor vasculature. Furthermore, some burst vents are found to be µm-sized, allowing the transport of 1 µm microspheres. Moreover, antibody drugs and platelets are capable of utilizing vascular burst transportation, demonstrating the application of this phenomenon to other types of therapeutics and cellular components. These findings indicate the vast potential of vascular bursts, extending the biological and therapeutic significance of this phenomenon to a wide range of blood-borne particles and cells.
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Nanopartículas , Neoplasias , Sistemas de Liberación de Medicamentos , Humanos , Liposomas , Micelas , Neoplasias/tratamiento farmacológico , Tamaño de la PartículaRESUMEN
Phosphorylcholine (PC) has been used to improve the water solubility and biocompatibility of biomaterials. Here, we show that PC can also work as a ligand for targeting cancer cells based on their increased phospholipid metabolism. PC-installed multiarm poly(ethylene glycol)s and polymeric micelles achieved high and rapid internalization in pancreatic cancer cells. This enhanced cellular uptake was drastically reduced when the cells were incubated with excess free PC or at 4 °C, as well as by inhibiting the phospholipid transfer protein (PLTP) on the surface of cancer cells, indicating an energy dependent active transport mediated by PLTP.
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Neoplasias Pancreáticas , Fosforilcolina , Humanos , Micelas , Neoplasias Pancreáticas/tratamiento farmacológico , Proteínas de Transferencia de Fosfolípidos , PolietilenglicolesRESUMEN
Self-assembled supramolecular structures based on polyion complex (PIC) formation between oppositely charged polymers are attracting much attention for developing drug delivery systems able to endure harsh in vivo environments. As controlling polymer complexation provides an opportunity for engineering the assemblies, an improved understanding of the PIC formation will allow constructing assemblies with enhanced structural and functional capabilities. Here, we focused on the influence of the mixing charge ratio between block aniomers and catiomers on the physicochemical characteristics and in vivo biological performance of the resulting PIC micelles (PIC/m). Our results showed that by changing the mixing charge ratio, the structural state of the core was altered despite the sizes of PIC/m remaining almost the same. These structural variations greatly affected the stability of the PIC/m in the bloodstream after intravenous injection and determined their biodistribution.
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Toxic aggregated amyloid-ß accumulation is a key pathogenic event in Alzheimer's disease (AD), which derives from amyloid precursor protein (APP) through sequential cleavage by BACE1 (ß-site APP cleavage enzyme 1) and γ-secretase. Small interfering RNAs (siRNAs) show great promise for AD therapy by specific silencing of BACE1. However, lack of effective siRNA brain delivery approaches limits this strategy. Here, we developed a glycosylated "triple-interaction" stabilized polymeric siRNA nanomedicine (Gal-NP@siRNA) to target BACE1 in APP/PS1 transgenic AD mouse model. Gal-NP@siRNA exhibits superior blood stability and can efficiently penetrate the blood-brain barrier (BBB) via glycemia-controlled glucose transporter-1 (Glut1)-mediated transport, thereby ensuring that siRNAs decrease BACE1 expression and modify relative pathways. Noticeably, Gal-NP@siBACE1 administration restored the deterioration of cognitive capacity in AD mice without notable side effects. This "Trojan horse" strategy supports the utility of RNA interference therapy in neurodegenerative diseases.
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Enfermedad de Alzheimer , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/terapia , Secretasas de la Proteína Precursora del Amiloide/genética , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/genética , Animales , Ácido Aspártico Endopeptidasas/genética , Ácido Aspártico Endopeptidasas/metabolismo , Barrera Hematoencefálica/metabolismo , Ratones , Ratones Transgénicos , Nanomedicina , ARN Interferente Pequeño/genéticaRESUMEN
For the simultaneous delivery of antisense oligonucleotides and their effector enzymes into cells, nanosized vesicular polyion complexes (PICs) were fabricated from oppositely charged polyion pairs of oligonucleotides and poly(ethylene glycol) (PEG)-b-polypeptides. First, the polyion component structures were carefully designed to facilitate a multimolecular (or secondary) association of unit PICs for noncovalent (or chemical cross-linking-free) stabilization of vesicular PICs. Chemically modified, single-stranded oligonucleotides (SSOs) dramatically stabilized the multimolecular associates under physiological conditions, compared to control SSOs without chemical modifications and duplex oligonucleotides. In addition, a high degree of guanidino groups in the polypeptide segment was also crucial for the high stability of multimolecular associates. Dynamic light scattering and transmission electron microscopy revealed the stabilized multimolecular associates to have a 100 nm sized vesicular architecture with a narrow size distribution. The loading number of SSOs per nanovesicle was determined to be â¼2500 using fluorescence correlation spectroscopic analyses with fluorescently labeled SSOs. Furthermore, the nanovesicle stably encapsulated ribonuclease H (RNase H) as an effector enzyme at â¼10 per nanovesicle through simple vortex-mixing with preformed nanovesicles. Ultimately, the RNase H-encapsulated nanovesicle efficiently delivered SSOs with RNase H into cultured cancer cells, thereby eliciting the significantly higher gene knockdown compared with empty nanovesicles (without RNase H) or a mixture of nanovesicles with RNase H without encapsulation. These results demonstrate the great potential of noncovalently stabilized nanovesicles for the codelivery of two varying bio-macromolecule payloads for ensuring their cooperative biological activity.
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Oligonucleótidos , Péptidos , Técnicas de Silenciamiento del Gen , Micelas , Oligonucleótidos/genética , PolietilenglicolesRESUMEN
Current strategies to direct therapy-loaded nanoparticles to the brain rely on functionalizing nanoparticles with ligands which bind target proteins associated with the blood-brain barrier (BBB). However, such strategies have significant brain-specificity limitations, as target proteins are not exclusively expressed at the brain microvasculature. Therefore, novel strategies which exploit alternative characteristics of the BBB are required to overcome nonspecific nanoparticle targeting to the periphery, thereby increasing drug efficacy and reducing detrimental peripheral side effects. Here, we present a simple, yet counterintuitive, brain-targeting strategy which exploits the higher impermeability of the BBB to selectively label the brain endothelium. This is achieved by harnessing the lower endocytic rate of brain endothelial cells (a key feature of the high BBB impermeability) to promote selective retention of free, unconjugated protein-binding ligands on the surface of brain endothelial cells compared to peripheral endothelial cells. Nanoparticles capable of efficiently binding to the displayed ligands (i.e., labeled endothelium) are consequently targeted specifically to the brain microvasculature with minimal "off-target" accumulation in peripheral organs. This approach therefore revolutionizes brain-targeting strategies by implementing a two-step targeting method which exploits the physiology of the BBB to generate the required brain specificity for nanoparticle delivery, paving the way to overcome targeting limitations and achieve clinical translation of neurological therapies. In addition, this work demonstrates that protein targets for brain delivery may be identified based not on differential tissue expression, but on differential endocytic rates between the brain and periphery.
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Barrera Hematoencefálica/metabolismo , Encéfalo/metabolismo , Portadores de Fármacos/metabolismo , Sistemas de Liberación de Medicamentos/instrumentación , Células Endoteliales/metabolismo , Nanopartículas/metabolismo , Animales , Transporte Biológico , Encéfalo/irrigación sanguínea , Endotelio/metabolismo , Humanos , Ratas , Ratas Sprague-DawleyRESUMEN
Controlling hydrogel surface wettability is of great importance in the viewpoint of engineering biomaterials that are in contact with cells and tissues. However, studies reporting how the hydrogel bulk properties would affect the surface is scarce, and thus it has been difficult to fabricate hydrogels with the desired properties. Also, there has been no effective method to elucidate this, due to the inhomogeneity introduced in the network structure of conventional hydrogels. Here we report our approach in elucidating the relationship between hydrogel physicochemical parameters and surface wettability by using Tetra-PEG gels, which are known to have homogeneous network structure. Specifically, the polymer volume fraction (φ) and the molecular weight (MW) between the cross-links were controlled. The number of anions, cations, and ionic pairs introduced within the hydrogel, were also individually controlled. The surface wettability of the resulting hydrogels was then evaluated. Results showed that surface wettability is largely dependent on the concentration of charged groups that are introduced in the hydrogel bulk, especially those that are not paired and ionically stabilized. Our findings strongly support the fact that with conventional hydrogels, the correlation between surface wettability and its physicochemical properties had not been evaluated appropriately, and thus our insights will contribute significantly to accumulating further knowledge on controlling hydrogel surface wettability.