Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32.498
Filtrar
1.
Macromol Biosci ; : e2400047, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589022

RESUMO

Polyaspartic acid derivatives are a well-known kind of polypeptide with good biocompatibility and biodegradability, and thus have been widely used as biomedical materials, including drug-loaded nano-scale micelles or macroscopic hydrogels. In this work, for the first time, monodisperse polyaspartic acid derivative microspheres with diameter ranging from 120 to 350 µm for potential tumor embolization therapy are successfully prepared by single emulsion droplet microfluidic technique. The obtained microsphere shows fast cationic anticancer drug doxorubicin hydrochloride loading kinetics with high loading capacity, which is much better than those of the commercial ones. Additionally, drug release behaviors of the drug-loaded microspheres with different diameters in different media are also studied and discussed in detail. These results provide some new insights for the preparation and potential application of polyaspartic acid derivative-based monodisperse microspheres, especially for their potential application as embolic agent.

2.
Carbohydr Polym ; 335: 122076, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38616075

RESUMO

The development of exopolysaccharide-based polymers is gaining increasing attention in various industrial biotechnology fields for materials such as thickeners, texture modifiers, anti-freeze agents, antioxidants, and antibacterial agents. High-viscosity carboxyethyl-succinoglycan (CE-SG) was directly synthesized from succinoglycan (SG) isolated from Sinorhizobium meliloti Rm 1021, and its structural, rheological, and physiological properties were investigated. The viscosity of CE-SG gradually increased in proportion to the degree of carboxyethylation substitution. In particular, when the molar ratio of SG and 3-chloropropionic acid was 1:100, the viscosity was significantly improved by 21.18 times at a shear rate of 10 s-1. Increased carboxyethylation of SG also improved the thermal stability of CE-SG. Furthermore, the CE-SG solution showed 90.18 and 91.78 % antibacterial effects against Escherichia coli and Staphylococcus aureus and effective antioxidant activity against DPPH and hydroxyl radicals. In particular, CE-SG hydrogels coordinated with Fe3+ ions, which improved both viscosity and rheological properties, while also exhibiting reduction-responsive drug release through 1,4-dithiothreitol. The results of this study suggest that SG derivatives, such as CE-SG, can be used as functional biomaterials in various fields such as food, cosmetics, and pharmaceutical industries.


Assuntos
Antioxidantes , Hidrogéis , Polissacarídeos Bacterianos , Hidrogéis/farmacologia , Antioxidantes/farmacologia , Antibacterianos/farmacologia , Indústria Farmacêutica , Escherichia coli
3.
Biol Pharm Bull ; 47(4): 848-855, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38616115

RESUMO

In this study, we prepared antisense oligonucleotide (ASO)-encapsulated nanoparticles (NPs) with a suitable profile for oral administration for the treatment of inflammatory bowel disease (IBD). We chose a water-in-oil-in-water (w/o/w) method to prepare the NPs using poly(lactide-co-glycolide) as a matrix and Pluronic as a stabilizer. The obtained NPs had a suitable diameter (158 nm) for the penetration of the mucus layer, endocytic uptake by enterocytes, and accumulation in inflammatory lesions in the intestine. The amount of ASOs in the NPs was relatively large (6.41% (w/w)). When the NPs were stably dispersed in solutions that mimicked gastrointestinal (GI) juice, minimal leakage of ASOs was demonstrated over the required period. The NPs were administered orally to mice with colitis induced by dextran sodium sulfate, which reduced target gene expression in the colons and rectums of the mice, whereas naked ASO administration caused no reduction in gene expression. Thus, the NPs have the potential of promising oral carriers of ASOs for the treatment of IBD that specifically target inflammatory lesions in the GI tract, thereby reducing the non-specific toxic effects of ASOs.


Assuntos
Doenças Inflamatórias Intestinais , Nanopartículas , Animais , Camundongos , Oligonucleotídeos Antissenso , Doenças Inflamatórias Intestinais/tratamento farmacológico , Administração Oral , Água
4.
Int J Nanomedicine ; 19: 3333-3365, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38617796

RESUMO

Cancer-associated fibroblasts (CAF) are the most abundant stromal cells in the tumor microenvironment (TME), especially in solid tumors. It has been confirmed that it can not only interact with tumor cells to promote cancer progression and metastasis, but also affect the infiltration and function of immune cells to induce chemotherapy and immunotherapy resistance. So, targeting CAF has been considered an important method in cancer treatment. The rapid development of nanotechnology provides a good perspective to improve the efficiency of targeting CAF. At present, more and more researches have focused on the application of nanoparticles (NPs) in targeting CAF. These studies explored the effects of different types of NPs on CAF and the multifunctional nanomedicines that can eliminate CAF are able to enhance the EPR effect which facilitate the anti-tumor effect of themselves. There also exist amounts of studies focusing on using NPs to inhibit the activation and function of CAF to improve the therapeutic efficacy. The application of NPs targeting CAF needs to be based on an understanding of CAF biology. Therefore, in this review, we first summarized the latest progress of CAF biology, then discussed the types of CAF-targeting NPs and the main strategies in the current. The aim is to elucidate the application of NPs in targeting CAF and provide new insights for engineering nanomedicine to enhance immune response in cancer treatment.


Assuntos
Fibroblastos Associados a Câncer , Nanopartículas , Neoplasias , Imunoterapia , Nanomedicina , Nanotecnologia , Neoplasias/tratamento farmacológico
5.
Artigo em Inglês | MEDLINE | ID: mdl-38618492

RESUMO

Extracellular vesicles (EVs) have emerged as a captivating field of study in molecular biology with diverse applications in therapeutics. These small membrane-bound structures, released by cells into the extracellular space, play a vital role in intercellular communication and hold immense potential for advancing medical treatments. EVs, including exosomes, microvesicles, and apoptotic bodies, are classified based on size and biogenesis pathways, with exosomes being the most extensively studied. The aim of this study was to examine the molecular secretory pathway of exosomes and to discuss the medical applications of exosomes and the methods for employing them in laboratory models. The therapeutic potential of EVs has garnered significant attention. Their unique properties, such as stability, biocompatibility, and capacity to traverse biological barriers, make them promising vehicles for targeted drug delivery. By engineering EVs to carry specific cargo molecules, such as therapeutic proteins, small interfering Ribonucleic Acid (RNAs) (siRNAs), or anti-cancer drugs, researchers can enhance drug stability and improve their targeted delivery to specific cells or tissues. This approach has the potential to minimize off-target effects and increase therapeutic efficacy, offering a more precise and effective treatment strategy. EVs represent a captivating and rapidly evolving field with significant therapeutic implications. Their role in intercellular communication, targeted drug delivery, and regenerative medicine makes them valuable tools for advancing medical treatments. As our understanding of EV biology and their therapeutic applications continues to expand, we can expect remarkable advancements that will revolutionize the field of medicine and lead to more personalized and effective therapies.

6.
Q Rev Biophys ; 57: e6, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38619322

RESUMO

A revolution in chemical biology occurred with the introduction of click chemistry. Click chemistry plays an important role in protein chemistry modifications, providing specific, sensitive, rapid, and easy-to-handle methods. Under physiological conditions, click chemistry often overlaps with bioorthogonal chemistry, defined as reactions that occur rapidly and selectively without interfering with biological processes. Click chemistry is used for the posttranslational modification of proteins based on covalent bond formations. With the contribution of click reactions, selective modification of proteins would be developed, representing an alternative to other technologies in preparing new proteins or enzymes for studying specific protein functions in different biological processes. Click-modified proteins have potential in diverse applications such as imaging, labeling, sensing, drug design, and enzyme technology. Due to the promising role of proteins in disease diagnosis and therapy, this review aims to highlight the growing applications of click strategies in protein chemistry over the last two decades, with a special emphasis on medicinal applications.


Assuntos
Química Click , Desenho de Fármacos , Rotulagem de Produtos , Processamento de Proteína Pós-Traducional , Tecnologia
7.
ACS Appl Bio Mater ; 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38620030

RESUMO

Transdermal drug delivery systems (TDDS) are a promising and innovative approach for breast cancer treatment, offering advantages such as noninvasiveness, potential for localized and prolonged drug delivery while minimizing systemic side effects through avoiding first-pass metabolism. Utilizing the distinctive characteristics of hydrogels, such as their biocompatibility, versatility, and higher drug loading capabilities, in the present work, we prepared ionic hydrogels through synergistic interaction between ionic liquids (ILs), choline alanine ([Cho][Ala]), and choline proline ([Cho][Pro]) with oleic acid (OA). ILs used in the study are biocompatible and enhance the solubility of 5-fluorouracil (5-FU), whereas OA is a known chemical penetration enhancer. The concentration-dependent (OA) change in morphological aggregates, that is, from cylindrical micelles to worm-like micelles to hydrogels was formed with both ILs and was characterized by SANS measurement, whereas the interactions involved were confirmed by FTIR spectroscopy. The hydrogels have excellent mechanical properties, which studied by rheology and their morphology through FE-SEM analysis. The in vitro skin permeation study revealed that both hydrogels penetrated 255 times ([Cho][Ala]) and 250 times ([Cho][Pro]) more as compared to PBS after 48 h. Those ionic hydrogels exhibited the capability to change the lipid and keratin arrangements within the skin layer, thereby enhancing the transdermal permeation of the 5-FU. Both ionic hydrogels exhibit excellent biocompatibility with normal cell lines (L-132 cells) as well as cancerous cell lines (MCF-7 cells), demonstrating over 92% cell viability after 48 h in both cell lines. In vitro, the cytotoxicity of the 5-FU-loaded hydrogels was evaluated on MCF-7 and HeLa cell lines. These results indicate that the investigated biocompatible and nontoxic ionic hydrogels enable the transdermal delivery of hydrophilic drugs, making them a viable option for effectively treating breast cancer.

8.
Int J Biol Macromol ; : 131516, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38621556

RESUMO

Simvastatin (SV) is a statin drug that can effectively control cholesterol and prevent cardiovascular diseases. However, SV is water-insoluble, and poor oral bioavailability (<5 %). Solid self-emulsifying carrier system is more stable than liquid emulsions, facilitating to improve the solubility and bioavailability of poorly soluble drugs. In the present study, a solid self-emulsifying carrier stabilized by casein (Cas-SSE) was successfully used to load SV to improve its solubility in water, by formulation selection and emulsification process optimization. Compared with oral tablets, the release of SV from Cas-SSE was significantly enhanced in artificial intestinal fluid. Furthermore, everted gut sac experiments indicated some water-soluble dispersing agents such as hydroxyethyl starch (HES), were not conducive to drug absorption. Pharmacokinetic studies suggested Cas-SSE without dispersing agent has much higher relative bioavailability (184.1 % of SV and 284.5 % of simvastatin acid) than SV tablet. The present work suggests Cas-SSE is a promising drug delivery platform with good biocompatibility for improving oral bioavailability of poorly water-soluble drugs.

9.
Int J Biol Macromol ; : 131590, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38621563

RESUMO

This work aimed to prepare a new system for daunorubicin (DNR) delivery to improve therapeutic efficiency and decrease unwanted side effects. Typically, at first, a carboxylic acid functional group containing metal-organic framework (UiO-66-COOH) was synthesized in a simple way. Then, a third generation of citric acid dendrimer (CAD G3) was grown on it (UiO-66-COOH-CAD G3). Finally, the system was functionalized with pre-modified hyaluronic acid (UiO-66-COOH-CAD-HA). SEM analysis displayed that the synthesized particles have a spherical shape with an average particle size ranging from 260 to 280 nm. An increase in hydrodynamic diameter from 223 nm for UiO-66-COOH to 481 nm for UiO-66-COOH-CAD-HA is a sign of success in the performed reactions. Also, the average pore size was calculated at about 4.04 nm. The DNR loading efficiency of UiO-66-COOH-CAD-HA was evaluated at ~74 % (DNR@UiO-66-COOH-CAD-HA). It was observed that the drug release rate at a lower pH is more than higher pH. The maximum hemolysis of <3 % means that the UiO-66-COOH-CAD-HA is hemocompatible. The use of DNR-loaded UiO-66-COOH-CAD-HA led to cell-killing of 77.9 % for MDA-MB 231. These results specified the great potential of UiO-66-COOH-CAD-HA for tumor drug delivery, so it could be proposed as a new carrier for anticancer agents to minimize adverse effects and improve therapeutic efficacy.

10.
Int J Pharm ; : 124098, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38621614

RESUMO

Glaucoma, the second most common cause of blindness worldwide, requires the development of new and effective treatments. This study introduces a novel controlled-release system utilizing elastin-like recombinamers (ELR) and the Supercritical Antisolvent (SAS) technique with supercritical CO2. Acetazolamide (AZM), a class IV drug with limited solubility and permeability, is successfully encapsulated in an amphiphilic ELR at three different ELR:AZM ratios, yielding up to 62 %. Scanning electron microscopy (SEM) reveals spherical microparticles that disintegrate into monodisperse nanoparticles measuring approximately 42 nm under physiological conditions. The nanoparticles, as observed via Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM), do not exhibit aggregates, a fact confirmed by the zeta potential displaying a value of -33 mV over a period of 30 days. Transcorneal permeation tests demonstrate a 10 % higher permeation level compared to the control solution, which increases to 30 % after 2 h. Ocular irritation tests demonstrate no adverse effects or damage. Intraocular pressure (IOP) tests conducted on hypertensive rabbits indicate greater effectiveness for all three analyzed formulations, suggesting enhanced drug bioavailability during treatment. Consequently, the combination of recombinant biopolymers and high-pressure techniques represents a promising approach for advancing glaucoma therapy, emphasizing its potential clinical significance.

11.
Int J Pharm ; : 124129, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38621615

RESUMO

Cationic liposomes specifically target monocytes in blood, rendering them promising drug-delivery tools for cancer immunotherapy, vaccines, and therapies for monocytic leukaemia. The mechanism behind this monocyte targeting ability is, however, not understood, but may involve plasma proteins adsorbed on the liposomal surfaces. To shed light on this, we investigated the biomolecular corona of three different types of PEGylated cationic liposomes, finding all of them to adsorb hyaluronan-associated proteins and proteoglycans upon incubation in human blood plasma. This prompted us to study the role of the TLR4 co-receptors CD44 and CD14, both involved in signalling and uptake pathways of proteoglycans and glycosaminoglycans. We found that separate inhibition of each of these receptors hampered the monocyte uptake of the liposomes in whole human blood. Based on clues from the biomolecular corona, we have thus identified two receptors involved in the targeting and uptake of cationic liposomes in monocytes, in turn suggesting that certain proteoglycans and glycosaminoglycans may serve as monocyte-targeting opsonins. This mechanistic knowledge may pave the way for rational design of future monocyte-targeting drug-delivery platforms.

12.
Pulm Ther ; 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622443

RESUMO

INTRODUCTION: Reusable nebulizer-compressor combinations deliver inhaled medications for patients with chronic lung diseases. On hospital discharge, the patient may take home the disposable nebulizer that was packaged and combine it with their home compressor. Though this practice may reduce waste, it can increase variability in medication delivery. Our study compared several reusable and disposable nebulizers packaged with compressor kits used in the US. We included a common disposable hospital nebulizer that may not be supplied with popular home kits but may be brought home after a hospitalization or emergency department visit. We focused on fine droplet mass < 4.7 µm aerodynamic diameter (FDM<4.7 µm), associated with medication delivery to the airways of the lungs. METHODS: We evaluated the following nebulizer-compressor combinations (n = 5 replicates): 1. OMBRA® Table Top Compressor with MC 300® reusable and Airlife™ MistyMax™ 10® disposable nebulizer, 2. Sami-the-Seal® compressor with SideStream® reusable and disposable nebulizers and Airlife™ MistyMax 10™ disposable nebulizer, 3. VIOS® compressor with LC Sprint® reusable, and VixOne® and Airlife™ MistyMax™ disposable nebulizers, 4. Innospire® Elegance® compressor with SideStream® reusable and disposable nebulizers and Airlife™ MistyMax 10™ disposable nebulizer, 5. Willis-the-Whale® compressor with SideStream® reusable and disposable nebulizers and Airlife™ MistyMax 10™ disposable nebulizer, 6. Pari PRONEB® Max compressor with LC Sprint® reusable and Airlife™ MistyMax 10™ disposable nebulizer. We placed a 3-ml albuterol solution (0.833 mg/ml) in each nebulizer. A bacterial/viral filter was attached to the nebulizer mouthpiece to capture emitted medication, with the filter exit coupled to a simulator of a tidal breathing adult (rate = 10 cycles/min; Vt = 600 ml; I/E ratio = 1:2). The filter was replaced at 1-min intervals until onset of sputter. Droplet size distributions (n = 5 replicates/system) were determined in parallel by laser diffractometry. RESULTS: Cumulative FDM<4.7 µm varied from 381 ± 33 µg for the best performing combination (Proneb/LC-Sprint) to 150 ± 21 µg for the system with the lowest output (VIOS®/MistyMax 10™). CONCLUSIONS: Substituting one nebulizer for another can result in large differences in medication delivery to the lungs.

13.
ACS Biomater Sci Eng ; 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622760

RESUMO

Triple-negative breast cancer (TNBC) lacks expressed protein targets, making therapy development challenging. Hydrogels offer a promising new route in this regard by improving the chemotherapeutic efficacy through increased solubility and sustained release. Moreover, subcutaneous hydrogel administration reduces patient burden by requiring less therapy and shorter treatment times. We recently established the design principles for the supramolecular assembly of single-domain coiled-coils into hydrogels. Using a modified computational design algorithm, we designed Q8, a hydrogel with rapid assembly for faster therapeutic hydrogel preparation. Q8 encapsulates and releases doxorubicin (Dox), enabling localized sustained release via subcutaneous injection. Remarkably, a single subcutaneous injection of Dox-laden Q8 (Q8•Dox) significantly suppresses tumors within just 1 week. This work showcases the bottom-up engineering of a fully protein-based drug delivery vehicle for improved TBNC treatment via noninvasive localized therapy.

14.
Eur J Clin Invest ; : e14208, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622800

RESUMO

BACKGROUND: Cardiovascular diseases (CVD) impact a substantial portion of the global population and represent a significant threat to experiencing life-threatening outcomes, such as atherosclerosis, myocardial infarction, stroke and heart failure. Despite remarkable progress in pharmacology and medical interventions, CVD persists as a major public health concern, and now ranks as the primary global cause of death and the highest consumer of global budgets. Ongoing research endeavours persist in seeking novel therapeutic avenues and interventions to deepen our understanding of CVD, enhance prevention measures, and refine treatment strategies. METHODS: Nanotechnology applied to the development of new molecular probes with diagnostic and theranostic properties represents one of the greatest technological challenges in preclinical and clinical research. RESULTS: The application of nanotechnology in cardiovascular medicine holds great promise for advancing our understanding of CVDs and revolutionizing their diagnosis and treatment strategies, ultimately improving patient care and outcomes. In addition, the capacity of drug encapsulation in nanoparticles has significantly bolstered their biological safety, bioavailability and solubility. In combination with imaging technologies, molecular imaging has emerged as a pivotal therapeutic tool, offering insight into the molecular events underlying disease and facilitating targeted treatment approaches. CONCLUSION: Here, we present a comprehensive overview of the recent advancements in targeted nanoparticle approaches for diagnosing CVDs, encompassing molecular imaging techniques, underscoring the significant progress in theranostic, as a novel and promising therapeutic strategy.

15.
Artigo em Inglês | MEDLINE | ID: mdl-38622933

RESUMO

Bubble-enhanced shock waves induce the transient opening of the blood-brain barrier (BBB) providing unique advantages for targeted drug delivery of brain tumor therapy, but little is known about the molecular details of this process. Based on our BBB model including 28 000 lipids and 280 tight junction proteins and coarse-grained dynamics simulations, we provided the molecular-level delivery mechanism of three typical drugs for the first time, including the lipophilic paclitaxel, hydrophilic gemcitabine, and siRNA encapsulated in liposome, across the BBB. The results show that the BBB is more difficult to be perforated by shock-induced jets than the human brain plasma membrane (PM), requiring higher shock wave speeds. For the pores formed, the BBB exhibits a greater ability to self-heal than PM. Hydrophobic paclitaxel can cross the BBB and be successfully absorbed, but the amount is only one-third of that of PM; however, the absorption of hydrophilic gemcitabine was almost negligible. Liposome-loaded siRNAs only stayed in the first layer of the BBB. The mechanism analysis shows that increasing the bubble size can promote drug absorption while reducing the risk of higher shock wave overpressure. An exponential function was proposed to describe the relation between bubble and overpressure, which can be extended to the experimental microbubble scale. The calculated overpressure is consistent with the experimental result. These molecular-scale details on shock-assisted BBB opening for targeted drug delivery would guide and assist experimental attempts to promote the application of this strategy in the clinical treatment of brain tumors.

16.
Artigo em Inglês | MEDLINE | ID: mdl-38623980

RESUMO

AIM AND OBJECTIVE: The aim of this study was to prepare polyvinyl alcohol/acrylic acid (PVA/AA) hydrogels for the controlled release of diclofenac sodium and to develop PVA/AA hydrogels as controlled release carriers to overcome not only the side effects of diclofenac sodium but also sustain its release for an extended period. BACKGROUND: Diclofenac sodium is employed for relieving pain and fever. The half-life of diclofenac sodium is very short (1-2 h). Hence, multiple intakes of diclofenac sodium are required to maintain a constant pharmacological action. Multiple GI adverse effects are produced as a result of diclofenac sodium intake. METHOD: A free radical polymerization technique was used for crosslinking PVA with AA in the presence of APS. EGDMA was used as a cross-linker. FTIR and XRD confirmed the preparation and loading of the drug by prepared hydrogels. An increase in the thermal stability of PVA was shown by TGA and DSC analysis. Surface morphology was investigated by SEM. Similarly, water penetration and drug loading were demonstrated by porosity and drug loading studies. The pH-sensitive nature of PVA/AA hydrogels was investigated at different pH values by swelling and drug release studies. RESULTS: The development and drug loading of PVA/AA hydrogels were confirmed by FTIR and XRD analysis. TGA and DSC indicated high thermal stability of prepared hydrogels as compared to unreacted PVA. SEM indicated a hard and compact network of developed hydrogels. The swelling and drug release studies indicated maximum swelling and drug release at high pH as compared to low pH values, indicating the pH-sensitive nature of prepared hydrogels. Moreover, we demonstrated that drug release was sustained for a prolonged time in a controlled pattern by prepared hydrogels by comparing the drug release of the developed hydrogels with the commercial product Cataflam. CONCLUSION: The results indicated that prepared PVA/AA hydrogels can be used as an alternative approach for the controlled delivery of diclofenac sodium.

17.
Mol Pharm ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38625037

RESUMO

Micellar drug delivery systems (MDDS) for the intravenous administration of poorly soluble drugs have great advantages over alternative formulations in terms of the safety of their excipients, storage stability, and straightforward production. A classic example is mixed micelles of glycocholate (GC) and lecithin, both endogenous substances in human blood. What limits the use of MDDS is the complexity of the transitions after injection. In particular, as the MDDS disintegrate partially or completely after injection, the drug has to be transferred safely to endogenous carriers in the blood, such as human serum albumin (HSA). If this transfer is compromised, the drug might precipitate─a process that needs to be excluded under all circumstances. The key question of this paper is whether the high local concentration of GC at the moment and site of MDDS dissolution might transiently saturate HSA binding sites and, hence, endanger quick drug transfer. To address this question, we have used a new approach, which is time-resolved fluorescence spectroscopy of the single tryptophan in HSA, Trp-214, to characterize the competitive binding of GC and the drug substitute anilinonaphthalenesulfonate (ANS) to HSA. Time-resolved fluorescence of Trp-214 showed important advantages over established methods for tackling this problem. ANS has been the standard "model drug" to study albumin binding for decades, given its structural similarity to the class of naphthalene-containing acidic drugs and the fact that it is displaced from HSA by numerous drugs (which presumably bind to the same sites). Our complex global fit uses the critical approximation that the average lifetimes behave similarly to a single lifetime, but the resulting errors are found to be moderate and the results provide a convincing explanation of the, at first glance, counterintuitive behavior. Accordingly, and largely in line with the literature, we observed two types of sites binding ANS at HSA: 3 type A, rather peripheral, and 2 type B, likely more central sites. The latter quench Trp-214 by Förster Resonance Energy Transfer (FRET) with a rate constant of ≈0.4 ns-1 per ANS. Adding millimolar concentrations of GC displaces ANS from the A sites but not from B sites. At incomplete ANS saturation, this causes a GC-induced translocation of ANS from A to the more FRET-active B sites. This leads to the apparent paradox that the partial displacement of ANS from HSA increases its quenching effect on Trp-214. The most important conclusion is that (ANS-like) drugs cannot be displaced from the type-B sites, and consequently, drug transfer to these sites is not impaired by competitive binding of GC in the vicinity of a dissolving micelle. The second conclusion is that for unbound GC above the CMC (9 mM), ANS equilibrates between HSA and GC micelles but with a strong preference for free sites on HSA. That means that even persisting micelles would lose their cargo readily once exposed to HSA. For all MDDS sharing this property, targeted drug delivery approaches involving them as the nanocarrier would be pointless.

18.
Food Sci Biotechnol ; 33(7): 1529-1540, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38623437

RESUMO

Microbial cellulose is a fermented form of very pure cellulose with a fibrous structure. The media rich in glucose or other carbon sources are fermented by bacteria to produce microbial cellulose. The bacteria use the carbon to produce cellulose, which grows as a dense, gel-like mat on the surface of the medium. The product was then collected, cleaned, and reused in various ways. The properties of microbial cellulose, such as water holding capacity, gas permeability, and ability to form a flexible, transparent film make it intriguing for food applications. Non-digestible microbial cellulose has been shown to improve digestive health and may have further advantages. It is also very absorbent, making it a great option for use in wound dressings. The review discusses the generation of microbial cellulose and several potential applications of microbial cellulose in fields including pharmacy, biology, materials research, and the food industry.

19.
Regen Biomater ; 11: rbae024, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38628546

RESUMO

Diabetic wounds are a difficult medical challenge. Excessive secretion of matrix metalloproteinase-9 (MMP-9) in diabetic wounds further degrades the extracellular matrix and growth factors and causes severe vascular damage, which seriously hinders diabetic wound healing. To solve these issues, a double-network porous hydrogel composed of poly (methyl methacrylate-co-acrylamide) (p(MMA-co-AM)) and polyvinyl alcohol (PVA) was constructed by the high internal phase emulsion (HIPE) technique for the delivery of potassium sucrose octasulfate (PSO), a drug that can inhibit MMPs, increase angiogenesis and improve microcirculation. The hydrogel possessed a typical polyHIPE hierarchical microstructure with interconnected porous morphologies, high porosity, high specific surface area, excellent mechanical properties and suitable swelling properties. Meanwhile, the p(MMA-co-AM)/PVA@PSO hydrogel showed high drug-loading performance and effective PSO release. In addition, both in vitro and in vivo studies showed that the p(MMA-co-AM)/PVA@PSO hydrogel had good biocompatibility and significantly accelerated diabetic wound healing by inhibiting excessive MMP-9 in diabetic wounds, increasing growth factor secretion, improving vascularization, increasing collagen deposition and promoting re-epithelialization. Therefore, this study provided a reliable therapeutic strategy for diabetic wound healing, some theoretical basis and new insights for the rational design and preparation of wound hydrogel dressings with high porosity, high drug-loading performance and excellent mechanical properties.

20.
Int J Pharm X ; 7: 100246, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38628619

RESUMO

The purpose of this study was to design novel drug nanocrystals (NCs) stabilized by glycyrrhizic acid (GL) for achieving liver targeted drug delivery due to the presence of GL receptor in the hepatocytes. Quercetin (QT) exhibits good pharmacological activities for the treatment of liver diseases, including liver steatosis, fatty hepatitis, liver fibrosis, and liver cancer. It was selected as a model drug owing to its poor water solubility. QT NCs stabilized by GL (QT-NCs/GL) were fabricated by wet media milling technique and systemically evaluated. QT-NCs stabilized by poloxamer 188 (QT-NCs/P188) were prepared as a reference for comparison of in vitro and in vivo performance with QT-NCs/GL. QT-NCs/GL and QT-NCs/P188 with similar particle size around 130 nm were successfully fabricated by wet media milling technique. Both of QT-NCs/GL and QT-NCs/P188 showed irregular particles and short rods under SEM. XRPD revealed that QT-NCs/GL and QT-NCs/P188 remained in crystalline state with reduced crystallinity. QT-NCs/GL and QT-NCs/P188 exhibited significant solubility increase and drug release improvement of QT as compared to raw QT. No significant difference for the plasma concentration-time curves and pharmacokinetic parameters of QT were found following intravenous administration of QT-NCs/GL and QT-NCs/P188. However, a significantly higher liver distribution of QT following intravenous administration of QT-NCs/GL was observed in comparison to QT-NCs/P188, indicating QT-NCs stabilized by GL could achieve liver targeted delivery of QT. It could be concluded that GL used as stabilizer of QT NCs have a great potential for liver targeted drug delivery.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...