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1.
Brain Sci ; 14(1)2024 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-38248297

RESUMO

Glioblastoma (GBM) is a primary malignant tumor of the central nervous system responsible for the most deaths among patients with primary brain tumors. Current therapies for GBM are not effective, with the average survival of GBM patients after diagnosis being limited to a few months. Chemotherapy is difficult in this case due to the heterogeneity of GBM and the high efficacy of the blood-brain barrier, which makes drug absorption into the brain extremely difficult. In a previous study, 3',4',3,4,5-trimethoxychalcone (MB) showed antiproliferative and anti-invasion activities toward GBM cells. Polymersomes (PMs) are an attractive, new type of nanoparticle for drug administration, due to their high stability, enhanced circulation time, biodegradability, and sustained drug release. In the present study, different MB formulations, PEG2000-PCL and PEG5000-PCL, were synthesized, characterized, and compared in terms of 14-day stability and in vitro cytotoxicity (hCMEC/D3 and U-373 MG).

2.
Life (Basel) ; 14(1)2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38255746

RESUMO

Glioblastoma (GBM) is the most common and deadly primary malignant brain tumor. Current therapies are insufficient, and survival for individuals diagnosed with GBM is limited to a few months. New GBM treatments are urgent. Polymeric nanoparticles (PNs) can increase the circulation time of a drug in the brain capillaries. Polymersomes (PMs) are PNs that have been described as having attractive characteristics, mainly due to their stability, prolonged circulation period, biodegradability, their ability to sustain the release of drugs, and the possibility of surface functionalization. In this work, a poly(ethylene glycol)-ε-caprolactone (PEG-PCL) copolymer was synthesized and PMs were prepared and loaded with an hydrolytic instable compound, previously synthesized by our research team, the 3,6-bis(2,3,4,6-tetra-O-acetyl-ß-glucopyranosyl)xanthone (XGAc), with promising cytotoxicity on glioblastoma cells (U-373 MG) but also on healthy cerebral endothelial cells (hCMEC/D3). The prepared PMs were spherical particles with uniform morphology and similar sizes (mean diameter of 200 nm) and were stable in aqueous suspension. The encapsulation of XGAc in PMs (80% encapsulation efficacy) protected the healthy endothelial cells from the cytotoxic effects of this compound, while maintaining cytotoxicity for the glioblastoma cell line U-373 MG. Our studies also showed that the prepared PMs can efficiently release XGAc at intratumoral pHs.

3.
Acta Pharm ; 73(4): 581-599, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38147480

RESUMO

Astaxanthin (ASTA) and zeaxanthin (ZEA) are xanthophyll carotenoids showing a wide spectrum of health-promoting properties. However, their utilization is limited, mostly due to poor water solubility, limited bioavailability, and a tendency to oxidate, as well as photo- and thermal instability. The aim of this work was to develop ASTA- and ZEA-loaded nano-structured lipid carriers (NLCs) that would protect them against degradation and improve their intestinal stability/permeability. Obtained NLCs were characterized by an effective diameter of 294 nm for ASTA-NLC and 280 nm for ZEA-NLC; polydispersity index (PDI) lower than 0.2; and zeta potential of -29.4 mV and -29.0 mV, respectively. Interestingly, despite similar physicochemical characteristics, our investigation revealed differences in the encapsulation efficiency of ASTA-NLC and ZEA-NLC (58.0 % vs. 75.5 %, respectively). Obtained NLCs were stable during a 21 day-storage period in the dark at room temperature or at 4 °C. Investigation of gastrointestinal stability showed no change in effective diameter and PDI under gastric conditions while both parameters significantly changed under intestinal conditions. Our results showed for the first time that both ASTA- and ZEA-NLCs intestinal absorption investigated in the in vitro model is significantly increased (in relation to pure compounds) and is affected by the presence of mucus. This study provides useful data about the advantages of using NLC as a delivery system for ASTA and ZEA that might facilitate their applications in the food and pharmaceutical industry.


Assuntos
Portadores de Fármacos , Nanoestruturas , Portadores de Fármacos/química , Zeaxantinas , Lipídeos/química , Nanoestruturas/química , Xantofilas , Permeabilidade , Tamanho da Partícula
4.
Int J Mol Sci ; 24(21)2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-37958698

RESUMO

Antimicrobial resistance is a silent pandemic considered a public health concern worldwide. Strategic therapies are needed to replace antibacterials that are now ineffective. One approach entails the use of well-known antibacterials along with adjuvants that possess non-antibiotic properties but can extend the lifespan and enhance the effectiveness of the treatment, while also improving the suppression of resistance. In this regard, a group of uniform materials based on organic salts (GUMBOS) presents an alternative to this problem allowing the combination of antibacterials with adjuvants. Fluoroquinolones are a family of antibacterials used to treat respiratory and urinary tract infections with broad-spectrum activity. Ciprofloxacin and moxifloxacin-based GUMBOS were synthesized via anion exchange reactions with lithium and sodium salts. Structural characterization, thermal stability and octanol/water partition ratios were evaluated. The antibacterial profiles of most GUMBOS were comparable to their cationic counterparts when tested against Gram-positive S. aureus and Gram-negative E. coli, except for deoxycholate anion, which demonstrated the least effective antibacterial activity. Additionally, some GUMBOS were less cytotoxic to L929 fibroblast cells and non-hemolytic to red blood cells. Therefore, these agents exhibit promise as an alternative approach to combining drugs for treating infections caused by resistant bacteria.


Assuntos
Fluoroquinolonas , Sais , Fluoroquinolonas/farmacologia , Sais/farmacologia , Sais/química , Escherichia coli , Staphylococcus aureus , Antibacterianos/química , Ânions , Testes de Sensibilidade Microbiana
6.
Sci Rep ; 13(1): 16667, 2023 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-37794129

RESUMO

Supplementing diets with rumen-protected lysine is a common strategy to meet the nutritional needs of high-producing dairy cows. This work addressed two separate but crucial issues: the lysine protection degree across the entire digestive tract as well as the production scalability of the proposed delivery systems. This was achieved by evaluating, in vitro or ex vivo, previously developed rumen-resistant lipid nanoparticles regarding their stability in the digestive tract and in the bloodstream of the dairy cow as well as how their production could be scaled-up. Results showed that the developed nanoparticles were able to resist digestion along the digestive tract but were degraded in the blood over 24 h. Thus, releasing their content to be used by the animal. In vitro viability assays were also performed, with the nanoparticles being found not to be inherently toxic when using nanoparticle concentrations up to 1 mg/mL. Results showed that neither the purity of the used lipids nor the production method significantly altered the nanoparticles' properties or their ruminal resistance. Furthermore, the shelf-life of these nanoparticles was assessed, and they were found to retain their properties and remain usable after at least 1 month of storage. Moreover, a pilot-scale production allowed the production of nanoparticles with similar properties to the previous ones made using standard methods. To summarize, the proposed rumen-resistant nanoparticles presented potential as orally ingested lysine delivery systems for dairy cattle supplementation, being capable of a large-scale production using cheaper components while maintaining their properties and without any efficiency loss. It should however be noted that these results were obtained mainly in vitro and further in vivo bioavailability and production experiments are needed before this technology can be confirmed as a viable way of delivering lysine to dairy cows.


Assuntos
Lisina , Nanopartículas , Animais , Feminino , Bovinos , Lisina/metabolismo , Leite/metabolismo , Lactação , Rúmen/metabolismo , Dieta/veterinária , Ração Animal/análise , Digestão , Fermentação
7.
Biomater Adv ; 151: 213488, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37285725

RESUMO

In chronic wound (CW) scenarios, Staphylococcus aureus-induced infections are very prevalent. This leads to abnormal inflammatory processes, in which proteolytic enzymes, such as human neutrophil elastase (HNE), become highly expressed. Alanine-Alanine-Proline-Valine (AAPV) is an antimicrobial tetrapeptide capable of suppressing the HNE activity, restoring its expression to standard rates. Here, we proposed the incorporation of the peptide AAPV within an innovative co-axial drug delivery system, in which the peptide liberation was controlled by N-carboxymethyl chitosan (NCMC) solubilization, a pH-sensitive antimicrobial polymer effective against Staphylococcus aureus. The microfibers' core was composed of polycaprolactone (PCL), a mechanically resilient polymer, and AAPV, while the shell was made of the highly hydrated and absorbent sodium alginate (SA) and NCMC, responsive to neutral-basic pH (characteristic of CW). NCMC was loaded at twice its minimum bactericidal concentration (6.144 mg/mL) against S. aureus, while AAPV was loaded at its maximum inhibitory concentration against HNE (50 µg/mL), and the production of fibers with a core-shell structure, in which all components could be detected (directly or indirectly), was confirmed. Core-shell fibers were characterized as flexible and mechanically resilient, and structurally stable after 28-days of immersion in physiological-like environments. Time-kill kinetics evaluations revealed the effective action of NCMC against S. aureus, while elastase inhibitory activity examinations proved the ability of AAPV to reduce HNE levels. Cell biology testing confirmed the safety of the engineered fiber system for human tissue contact, with fibroblast-like cells and human keratinocytes maintaining their morphology while in contact with the produced fibers. Data confirmed the engineered drug delivery platform as potentially effective for applications in CW care.


Assuntos
Quitosana , Infecções Estafilocócicas , Humanos , Alginatos/farmacologia , Quitosana/farmacologia , Quitosana/química , Elastase de Leucócito/metabolismo , Elastase de Leucócito/farmacologia , Peptídeos/farmacologia , Polímeros/farmacologia , Staphylococcus aureus/metabolismo , Valina/farmacologia , Ferimentos e Lesões/complicações , Ferimentos e Lesões/microbiologia , Ferimentos e Lesões/terapia , Cicatrização/efeitos dos fármacos , Cicatrização/fisiologia
8.
NPJ Biofilms Microbiomes ; 9(1): 39, 2023 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-37328504

RESUMO

Staphylococcus aureus is considered a high priority pathogen by the World Health Organization due to its high prevalence and the potential to form biofilms. Currently, the available treatments for S. aureus biofilm-associated infections do not target the extracellular polymeric substances (EPS) matrix. This matrix is a physical barrier to bactericidal agents, contributing to the increase of antimicrobial tolerance. The present work proposes the development of lipid nanoparticles encapsulating caspofungin (CAS) as a matrix-disruptive nanosystem. The nanoparticles were functionalized with D-amino acids to target the matrix. In a multi-target nano-strategy against S. aureus biofilms, CAS-loaded nanoparticles were combined with a moxifloxacin-loaded nanosystem, as an adjuvant to promote the EPS matrix disruption. In vitro and in vivo studies showed biofilm reduction after combining the two nanosystems. Besides, the combinatory therapy showed no signs of bacterial dissemination into vital organs of mice, while dissemination was observed for the treatment with the free compounds. Additionally, the in vivo biodistribution of the two nanosystems revealed their potential to reach and accumulate in the biofilm region, after intraperitoneal administration. Thus, this nano-strategy based on the encapsulation of matrix-disruptive and antibacterial agents is a promising approach to fight S. aureus biofilms.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Animais , Camundongos , Distribuição Tecidual , Biofilmes , Infecções Estafilocócicas/microbiologia , Antibacterianos/farmacologia , Antibacterianos/química
9.
Int J Mol Sci ; 24(12)2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37373056

RESUMO

Understanding how nanoparticles' properties influence their cellular interactions is a bottleneck for improving the design of carriers. Macrophage polarization governs their active role in solving infections or tissue repair. To unravel the effect of carbohydrate-targeting mannose receptors on the macrophage surface, drug-free fucoidan/chitosan nanoparticles were functionalized using mannose (M) and mannan (Mn). Polyelectrolyte complex nanoparticles were obtained upon chitosan self-assembly using fucoidan. The functionalized nanoparticles were characterized in terms of their physicochemical characteristics, chemical profile, and carbohydrate orientation. The nanoparticles varied in size from 200 to 400 nm, were monodisperse, and had a stable negative zeta potential with a low aggregation tendency. The nonfunctionalized and functionalized nanoparticles retained their properties for up to 12 weeks. Cell viability and internalization studies were performed for all the designed nanoparticles in the THP-1 monocytes and THP-1-differentiated macrophages. The expression of the mannose receptor was verified in both immune cells. The carbohydrate-functionalized nanoparticles led to their activation and the production of pro-inflammatory cytokines interleukin (IL)-1ß, IL-6, and tumour necrosis factor (TNF)-α. Both M- and Mn-coated nanoparticles modulate macrophages toward an M1-polarized state. These findings demonstrate the tailoring of these nanoplatforms to interact and alter the macrophage phenotype in vitro and represent their therapeutic potential either alone or in combination with a loaded drug for future studies.


Assuntos
Quitosana , Nanopartículas , Receptor de Manose , Quitosana/farmacologia , Quitosana/metabolismo , Macrófagos/metabolismo , Nanopartículas/química , Manose/metabolismo
10.
Adv Drug Deliv Rev ; 199: 114969, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37348678

RESUMO

Nystatin is an antifungal molecule with a remarkable yet squandered versatility. In this review, its mechanism of action is explored, along with its extensive action spectrum and toxicity. A multitude of methodologies to tackle the drug's physical and chemical hurdles are outlined along with some proven-effective strategies to increase its activity and/or decrease its toxicity. A separate detailed section focused on micro and nanotechnology solutions addresses new drug delivery systems made of polymeric, metallic or lipid materials. Although the topical route depicts greater representativeness amongst these formulations, the intravenous, dental, oral, vaginal and inhalation routes are also mentioned. The unsuccessful previous attempts at developing parenteral formulations of nystatin or even the withdrawal of a nystatin-loaded multilamellar liposome should not divert research away from this drug. In fact, the interest in nystatin ought to be reawakened with the ongoing clinical trials on the promising nystatin-like genetically engineered derivate BSG005.


Assuntos
Antifúngicos , Nistatina , Humanos , Antifúngicos/uso terapêutico , Antifúngicos/farmacologia , Nistatina/farmacologia , Nistatina/uso terapêutico , Lipossomos , Sistemas de Liberação de Medicamentos , Polímeros
11.
Biomater Adv ; 151: 213443, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37146526

RESUMO

Photothermal therapy has emerged as a new promising strategy for the management of cancer, either alone or combined with other therapeutics, such as chemotherapy. The use of nanoparticles for multimodal therapy can improve treatment performance and reduce drug doses and associated side effects. Here we propose the development of a novel multifunctional nanosystem based on solid lipid nanoparticles co-loaded with gold nanorods and mitoxantrone and functionalized with folic acid for dual photothermal therapy and chemotherapy of breast cancer. Nanoparticles were produced using an economically affordable method and presented suitable physicochemical properties for tumor passive accumulation. Upon Near-Infrared irradiation (808 nm, 1.7 W cm-2, 5 min), nanoparticles could effectively mediate a temperature increase of >20 °C. Moreover, exposure to light resulted in an enhanced release of Mitoxantrone. Furthermore, nanoparticles were non-hemolytic and well tolerated by healthy cells even at high concentrations. The active targeting strategy was found to be successful, as shown by the greater accumulation of the functionalized nanoparticles in MCF-7 cells. Finally, the combined effects of chemotherapy, light-induced drug release and photothermal therapy significantly enhanced breast cancer cell death. Overall, these results demonstrate that the developed lipid nanosystem is an efficient vehicle for breast cancer multimodal therapy.


Assuntos
Neoplasias da Mama , Nanopartículas , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Mitoxantrona/uso terapêutico , Terapia Fototérmica , Nanopartículas/uso terapêutico , Nanopartículas/química
12.
Vaccines (Basel) ; 11(4)2023 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-37112645

RESUMO

Nanoparticles include particles ranging in size from nanometers to micrometers, whose physicochemical characteristics are optimized to make them appropriate delivery vehicles for drugs or immunogens important in the fight and/or prevention of infectious diseases. There has been a rise in the use of nanoparticles in preventive vaccine formulations as immunostimulatory adjuvants, and as vehicles for immunogen delivery to target immune cells. Toxoplasma is important worldwide, and may cause human toxoplasmosis. In immunocompetent hosts, infection is usually asymptomatic, but in immunocompromised patients it can cause serious neurological and ocular consequences, such as encephalitis and retinochoroiditis. Primary infection during pregnancy may cause abortion or congenital toxoplasmosis. Currently, there is no effective human vaccine against this disease. Evidence has emerged from several experimental studies testing nanovaccines showing them to be promising tools in the prevention of experimental toxoplasmosis. For the present study, a literature review was carried out on articles published over the last 10 years through the PubMed database, pertaining to in vivo experimental models of T. gondii infection where nanovaccines were tested and protection and immune responses evaluated. This review aims to highlight the way forward in the search for an effective vaccine for toxoplasmosis.

13.
Membranes (Basel) ; 13(2)2023 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-36837642

RESUMO

Cationic antimicrobial peptides (CAMPs) offer a promising strategy to counteract bacterial resistance, mostly due to their membrane-targeting activity. W-BP100 is a potent broad-spectrum cecropin-melittin CAMP bearing a single N-terminal Trp, which was previously found to improve its antibacterial activity. W-BP100 has high affinity toward anionic membranes, inducing membrane saturation at low peptide-to-lipid (P/L) ratios and membrane permeabilization, with the unique property of promoting the aggregation of anionic vesicles only at specific P/L ratios. Herein, we aimed to investigate this unusual behavior of W-BP100 by studying its aggregation and fusion properties with negatively-charged large (LUVs) or giant (GUVs) unilamellar vesicles using biophysical tools. Circular dichroism (CD) showed that W-BP100 adopted an α-helical conformation in anionic LUVs, neutralizing its surface charge at the aggregation P/L ratio. Its fusion activity, assessed by Förster resonance energy transfer (FRET) using steady-state fluorescence spectroscopy, occurred mainly at the membrane saturation/aggregation P/L ratio. Confocal microscopy studies confirmed that W-BP100 displays aggregation and detergent-like effects at a critical P/L ratio, above which it induces the formation of new lipid aggregates. Our data suggest that W-BP100 promotes the aggregation and fusion of anionic vesicles at specific P/L ratios, being able to reshape the morphology of GUVs into new lipid structures.

14.
Eur J Pharm Biopharm ; 184: 214-247, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36773725

RESUMO

Cutaneous melanoma (CM) is a multifactorial disease whose treatment still presents challenges: the rapid progression to advanced CM, which leads to frequent recurrences even after surgical excision and, notably, the low response rates and resistance to the available therapies, particularly in the case of unresectable metastatic CM. Thereby, alternative innovative therapeutic approaches for CM continue to be searched. In this review we discuss relevant preclinical research studies, and provide a broad-brush analysis of patents and clinical trials which involve the application of nanotechnology-based delivery systems in CM therapy. Nanodelivery systems have been developed for the delivery of anticancer biomolecules to CM, which can be administered by different routes. Overall, nanosystems could promote technological advances in several therapeutic modalities and can be used in combinatorial therapies. Nevertheless, the results of these preclinical studies have not been translated to clinical applications. Thus, concerted and collaborative research studies involving basic, applied, translational, and clinical scientists need to be performed to allow the development of effective and safe nanomedicines to treat CM.


Assuntos
Melanoma , Neoplasias Cutâneas , Humanos , Neoplasias Cutâneas/patologia , Sistemas de Liberação de Fármacos por Nanopartículas , Administração Cutânea
15.
Cancers (Basel) ; 15(2)2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36672333

RESUMO

Colorectal cancer is the third most common cancer worldwide. Despite recent advances in the treatment of this pathology, which include a personalized approach using radio- and chemotherapies in combination with advanced surgical techniques, it is imperative to enhance the performance of these treatments and decrease their detrimental side effects on patients' health. Nanomedicine is likely the pathway towards solving this challenge by enhancing both the therapeutic and diagnostic capabilities. In particular, plasmonic nanoparticles show remarkable potential due to their dual therapeutic functionalities as photothermal therapy agents and as radiosensitizers in radiotherapy. Their dual functionality, high biocompatibility, easy functionalization, and targeting capabilities make them potential agents for inducing efficient cancer cell death with minimal side effects. This review aims to identify the main challenges in the diagnosis and treatment of colorectal cancer. The heterogeneous nature of this cancer is also discussed from a single-cell point of view. The most relevant works in photo- and radiotherapy using nanotechnology-based therapies for colorectal cancer are addressed, ranging from in vitro studies (2D and 3D cell cultures) to in vivo studies and clinical trials. Although the results using nanoparticles as a photo- and radiosensitizers in photo- and radiotherapy are promising, preliminary studies showed that the possibility of combining both therapies must be explored to improve the treatment efficiency.

16.
Pharmaceutics ; 15(1)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36678818

RESUMO

Marine polysaccharides are recognized for their biological properties and their application in the drug delivery field, favoring hydrogel-forming capacities for cutaneous application towards several dermatological conditions. Essential oils have been widely used in skin, not only for their remarkable biological properties, but also for their capacity to enhance permeation through the skin layers and to confer a pleasant scent to the formulation. In this study, menthol, L-linalool, bergamot oil, and ß-pinene were incorporated in alginate/fucoidan hydrogels to evaluate their skin permeation enhancement profile and assess their influence on the skin organization. The combinations of different essential oils with the marine-based fucoidan/alginate hydrogel matrix were characterized, resulting in formulations with pseudoplastic rheological properties favorable for a uniform application in the skin. The ex vivo Franz diffusion permeation assays revealed that calcein loaded in bergamot-alginate/fucoidan hydrogel permeated more than 15 mg out of the initial 75 mg than when in linalool-alginate/fucoidan, alginate/fucoidan or hydrogel without any incorporated oil. Skin calcein retention for menthol- and pinene-alginate/fucoidan hydrogels was 15% higher than in the other conditions. Infrared micro-spectroscopic analysis through synchrotron-based Fourier Transform Infrared Microspectroscopy evidenced a symmetric shift in CH3 groups towards higher wavenumber, indicating lipids' fluidization and less lateral packing, characterized by a band at 1468 cm-1, with the bergamot-alginate/fucoidan, which contributes to enhancing skin permeation. The study highlights the effect of the composition in the design of formulations for topical or transdermal delivery systems.

17.
Biochim Biophys Acta Biomembr ; 1865(3): 184115, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36603803

RESUMO

There is a growing need for alternatives to target and treat bacterial infection. Thus, the present work aims to develop and optimize the production of PEGylated magnetoliposomes (MLPs@PEG), by encapsulating superparamagnetic iron oxide nanoparticles (SPIONs) within fusogenic liposomes. A Box-Behnken design was applied to modulate size distribution variables, using lipid concentration, SPIONs amount and ultrasonication time as independent variables. As a result of the optimization, it was possible to obtain MLPs@PEG with a mean size of 182 nm, with polydispersity index (PDI) of 0.19, and SPIONs encapsulation efficiency (%EE) around 76%. Cytocompatibility assays showed that no toxicity was observed in fibroblasts, for iron concentrations up to 400µg/ml. Also, for safe lipid and iron concentrations, no hemolytic effect was detected. The fusogenicity of the nanosystems was first evaluated through lipid mixing assays, based on Förster resonance energy transfer (FRET), using liposomal membrane models, mimicking bacterial cytoplasmic membrane and eukaryotic plasma membrane. It was shown that the hybrid nanosystems preferentially interact with the bacterial membrane model. Confocal microscopy and fluorescence lifetime measurements, using giant unilamellar vesicles (GUVs), validated these results. Overall, the developed hybrid nanosystem may represent an efficient drug delivery system with improved targetability for bacterial membrane.


Assuntos
Sistemas de Liberação de Medicamentos , Lipossomas Unilamelares , Ferro , Lipídeos
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 287(Pt 2): 122118, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36401918

RESUMO

A fast, simple, and reliable method for determination of metformin was developed by coupling surface-enhanced Raman spectroscopy (SERS) with chemometric methods. This relayed on the utilization of a portable Raman spectrometer and of citrate stabilized gold nanoparticles (AuNPs) as substrate, to carry out the measurement of SERS scattering signals, thus assuring improved sensitivity. The obtained datasets were analysed using principal component analysis (PCA) and partial least squares (PLS) regression. Upon optimization of the PLS model, in terms of latent variables, spectral region and pre-processing techniques, RMSECV and R2CV values of 0.42 mg/L and 0.94, respectively, were obtained. The optimized PLS regression model was further validated with the projection of commercial pharmaceutical samples, providing good results in terms of R2P (0.97), RE (4.54 %) and analytical sensitivity (2.13 mg/L).


Assuntos
Nanopartículas Metálicas , Metformina , Análise Espectral Raman , Ouro , Quimiometria
19.
Polymers (Basel) ; 16(1)2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38201685

RESUMO

An enormous interest in the development of efficient protocols for cellulose extraction has been demonstrated in the last few years, although usually based on non-sustainable chemical and thermal approaches. In this work, we propose a new and more sustainable method for cellulose extraction from eucalyptus and pine tree wood waste products exclusively performed using microwave-assisted radiation. The methodology includes three main steps: (i) alkaline treatment; (ii) bleaching I, using H2O2; and (iii) bleaching II, an acidic treatment. Samples obtained in each step were characterized by Fourier-transform Infrared (FTIR) spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results were compared with the structural and thermal profile of the starting materials, a commercially available microcrystalline cellulose and with an industrial paper pulp sample. Results confirmed that for both types of wood wastes, cellulose was retained during the extraction procedures and that the removal of hemicellulose and lignin was mainly achieved in the last step, as seen by the FTIR spectra and TGA curves. The developed protocol is innovative, as it constitutes an easy and quick approach for extracting cellulose from eucalyptus and pine tree wood waste. Mild chemical and thermal conditions are used during the three extraction steps (microwave irradiation, aqueous solutions, maximum of 120 °C in a total of 3 h). Moreover, environmentally friendly purification steps are applied based on the use of water and ethanol. This approach offers the possibility of a future scale-up study to potentially apply the developed protocol to the extraction of cellulose on an industrial scale.

20.
Pharmaceutics ; 14(12)2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36559239

RESUMO

The major risk factor associated with the development of gastric cancer is chronic infection with Helicobacter pylori. The available treatments, based on a cocktail of antibiotics, fail in up to 40% of patients and disrupt their gut microbiota. The potential of blank nanostructured lipid carriers (NLC) for H. pylori eradication was previously demonstrated by us. However, the effect of NLC charge, size and protein corona on H. pylori-specific bactericidal activity herein studied was unknown at that time. All developed NLC formulations proved bactericidal against H. pylori. Although cationic NLC had 10-fold higher bactericidal activity than anionic NLC, they lacked specificity, since Lactobacillus acidophilus was also affected. Anionic NLC achieved complete clearance in both H. pylori morphologies (rod- and coccoid-shape) by inducing alterations in bacteria membranes and the cytoplasm, as visualized by transmission electron microscopy (TEM). The presence of an NLC protein corona, composed of 93% albumin, was confirmed by mass spectrometry. This protein corona delayed the bactericidal activity of anionic NLC against H. pylori and hindered NLC activity against Escherichia coli. Overall, these results sustain the use of NLC as a promising antibiotic-free strategy targeting H. pylori.

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