RESUMO

Advanced breast cancer remains a significant oncological challenge, requiring new approaches to improve clinical outcomes. This study investigated an innovative theranostic agent using the MCM-41-NH2-DTPA-Gd3⁺-MIH nanomaterial, which combined MRI imaging for detection and a novel chemotherapy agent (MIH 2.4Bl) for treatment. The nanomaterial was based on the mesoporous silica type, MCM-41, and was optimized for drug delivery via functionalization with amine groups and conjugation with DTPA and complexation with Gd3+. MRI sensitivity was enhanced by using gadolinium-based contrast agents, which are crucial in identifying early neoplastic lesions. MIH 2.4Bl, with its unique mesoionic structure, allows effective interactions with biomolecules that facilitate its intracellular antitumoral activity. Physicochemical characterization confirmed the nanomaterial synthesis and effective drug incorporation, with 15% of MIH 2.4Bl being adsorbed. Drug release assays indicated that approximately 50% was released within 8 h. MRI phantom studies demonstrated the superior imaging capability of the nanomaterial, with a relaxivity significantly higher than that of the commercial agent Magnevist. In vitro cellular cytotoxicity assays, the effectiveness of the nanomaterial in killing MDA-MB-231 breast cancer cells was demonstrated at an EC50 concentration of 12.6 mg/mL compared to an EC50 concentration of 68.9 mg/mL in normal human mammary epithelial cells (HMECs). In vivo, MRI evaluation in a 4T1 syngeneic mouse model confirmed its efficacy as a contrast agent. This study highlighted the theranostic capabilities of MCM-41-NH2-DTPA-Gd3⁺-MIH and its potential to enhance breast cancer management.

Assuntos

Neoplasias da Mama , Imageamento por Ressonância Magnética , Nanopartículas , Dióxido de Silício , Nanomedicina Teranóstica , Dióxido de Silício/química , Animais , Humanos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Feminino , Nanomedicina Teranóstica/métodos , Imageamento por Ressonância Magnética/métodos , Camundongos , Linhagem Celular Tumoral , Nanopartículas/química , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Meios de Contraste/química , Gadolínio/química , Porosidade , Ensaios Antitumorais Modelo de Xenoenxerto

RESUMO

The need to find alternative materials to replace aqueous amine solutions for the capture of CO2 in post-combustion technologies is pressing. This study assesses the CO2 sorption capacity and CO2/N2 selectivity of three dicationic ionic liquids with distinct anions immobilized in commercial mesoporous silica support (SBA- 15). The samples were characterized by UART-FTIR, NMR, Raman, FESEM, TEM, TGA, Magnetometry (VSM), BET and BJH. The highest CO2 sorption capacity and CO2/N2 selectivity were obtained for sample SBA@DIL_2FeCl4 [at 1 bar and 25 °C; 57.31 (±0.02) mg CO2/g; 12.27 (±0.72) mg CO2/g]. The results were compared to pristine SBA-15 and revealed a similar sorption capacity, indicating that the IL has no impact on the CO2 sorption capacity of silica. On the other hand, selectivity was improved by approximately 3.8 times, demonstrating the affinity of the ionic liquid for the CO2 molecule. The material underwent multiple sorption/desorption cycles and proved to be stable and a promising option for use in industrial CO2 capture processes.

RESUMO

Quercetin (Q) dietary supplements exhibit poor oral bioavailability because of degradation throughout gastrointestinal digestion (GD), which may be overcome using mesoporous silica particles (MSPs) as an oral delivery system (ODS). This study aimed to elucidate the effect of the functionalization of MSPs with amine-(A-MSP), carboxyl-(C-MSP), or thiol-(T-MSP) groups on their efficiency as a quercetin ODS (QODS). The type and degree of functionalization (DF) were used as factors in an experimental design. The Q-loaded F-MSP (F-MSP/Q) was characterized by gas physisorption analysis, loading capacity (LC), and dynamic light scattering and kinetics of Q release at gastric and intestinal pHs. Antioxidant capacity and Q concentration of media containing F-MSP/Q were evaluated after simulated GD. A-MSP showed the highest LC (19.79 ± 2.42%). C-MSP showed the lowest particle size at pH 1.5 or 7.4 (≈200 nm). T-MSP exhibited the maximum Q release at pH 7.4 (11.43%). High DF of A-MSP increased Q retention, regardless of pH. A-MSP preserved antioxidant capacity of Q-released gastric media (58.95 ± 3.34%). Nonetheless, MSP and F-MSP did not protect antioxidant properties of Q released in intestinal conditions. C-MSP and T-MSP showed essential features for cellular uptake and Q release within cells that need to be assessed.

RESUMO

Stimuli-responsive nanocarriers are being widely applied in the development of new strategies for the diagnosis and treatment of diseases. An inherent difficulty in general drug therapy is the lack of precision with respect to a specific pathological site, which can lead to toxicity, excessive drug consumption, or premature degradation. In this work, the controlled drug delivery is achieved by using magnetite nanoparticles coated with mesoporous silica with core-shell structure (MMS) and grafted with the thermoresponsive polymer poly [N-isopropylacrylamide-co-3-(trimethoxysilyl)propyl methacrylate] (MMS-P). The efficiency of MMS-P as a temperature-controlled drug delivery system was evaluated by in vitro release experiments using ibuprofen (IBU) in various mammalian cell models. Further, the effects of IBU as a photoprotectant in cells exposed to photodynamic therapy (PDT) in a carbaryl-induced neurodegenerative model were evaluated. The results showed that MMS-P nanocarriers do not exhibit cytotoxicity in HepG2 cells at high doses such as 7600 µg mL-1. Pre-incubation of MMS-P charged with IBU showed no effect on the PDT in N2A cells; however, it produced a further decrease in the viability of HepG2 cells, leading to a reduction to PDT resistance. On the other hand, a cytoprotective effect against carbaryl toxicity in N2A cells was observed in IBU administrated by MMS-P, which confirms the effective intracellular IBU uptake by means of MMS-P. These results encourage the potential application of MMS-P as a drug delivery system and confirm the effect of IBU as a cytoprotective agent in a neurodegenerative model.

Assuntos

Ibuprofeno , Nanopartículas , Ibuprofeno/química , Carbaril , Sistemas de Liberação de Medicamentos , Polímeros/química , Fenômenos Magnéticos , Dióxido de Silício/química , Nanopartículas/química

RESUMO

Stimuli-responsive nanomaterials have emerged as a promising strategy for inclusion in anticancer therapy. In particular, pH-responsive silica nanocarriers have been studied to provide controlled drug delivery in acidic tumor microenvironments. However, the intracellular microenvironment that the nanosystem must face has an impact on the anticancer effect; therefore, the design of the nanocarrier and the mechanisms that govern drug release play a crucial role in optimizing efficacy. Here, we synthesized and characterized mesoporous silica nanoparticles with transferrin conjugated on their surface via a pH-sensitive imine bond (MSN-Tf) to assess camptothecin (CPT) loading and release. The results showed that CPT-loaded MSN-Tf (MSN-Tf@CPT) had a size of ca. 90 nm, a zeta potential of -18.9 mV, and a loaded content of 13.4%. The release kinetic data best fit a first-order model, and the predominant mechanism was Fickian diffusion. Additionally, a three-parameter model demonstrated the drug-matrix interaction and impact of transferrin in controlling the release of CPT from the nanocarrier. Taken together, these results provide new insights into the behavior of a hydrophobic drug released from a pH-sensitive nanosystem.

RESUMO

Cinnamon (Cinnamomum zeylanicum Blume) essential oil has vast potential as an antimicrobial but is limited by its volatility and rapid degradation. To decrease its volatility and prolong the efficacy of the biocide, cinnamon essential oil was encapsulated into mesoporous silica nanoparticles (MSNs). The characterization of MSNs and cinnamon oil encapsulated with silica nanoparticles (CESNs) was estimated. Additionally, their insecticidal activity against the rice moth Corcyra cephalonica (Stainton) larvae was evaluated. The MSN surface area decreased from 893.6 to 720 m2 g-1 and the pore volume also decreased from 0.824 to 0.7275 cc/g after loading with cinnamon oil. X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and N2 sorption by Brunauer-Emmett-Teller (BET) confirmed the successful formation and evolution of the synthesized MSNs and CESN structures. The surface characteristics of MSNs and CESNs were analyzed by scanning and transmission electron microscopy. Compared with the sub-lethal activity values, the order of toxicity after 6 days of exposure was MSNs ˃ CESN ˃ cinnamon oil ˃ silica gel ˃ peppermint oil. The efficacy of CESNs gradually increases its toxicity more than MSN after the 9th day of exposure.

Assuntos

Mariposas , Nanopartículas , Óleos Voláteis , Animais , Cinnamomum zeylanicum , Dióxido de Silício/química , Nanopartículas/química

RESUMO

The algal organic matter (AOM) is a problem in water treatment. Although the adsorption process is extensively applied to drinking water treatment, little information is known about the potential of new adsorbents to remove AOM. Herein, this work evaluated the removal of AOM and its main compounds (dissolved organic carbon (DOC), carbohydrate, and protein) by new adsorbents-mesoporous silica (SBA-16), graphene oxide material from citric acid (CA), and sugar (SU), and a composite of CA immobilized on sand (GSC). In general, the removal efficiencies followed the order of SBA-16 > CA > SU or GSC for DOC, carbohydrate, and protein. At environmental condition (5 mg DOC·L-1 and pH 8), high removals were reported for SBA-16 (88.8% DOC, 80.0% carbohydrate, and 99.6% protein) and CA (70.0% DOC, 66.7% carbohydrate, and 89.7% protein), while moderate removals were found for SU (60.5% DOC, 47.9% carbohydrate, and 66.5% protein) and GSC (67.4% DOC, 60.8% carbohydrate, and 57.4% protein). Based on these results, further analyses were done with SBA-16 and CA. Both adsorbents' efficiencies decayed with the pH increment of the test water. Disinfection by-products reductions found using SBA-16 - trihalomethanes (58.2 to 94.7%) and chloral hydrate (48.7 to 78.8%) - were higher than the ones using CA-trihalomethanes (45.2 to 82.4%) and chloral hydrate (40.1 to 70.8%). This study showed the potential of applying these adsorbents for AOM removal, and further investigations are suggested to increase the adsorption capacity of these adsorbents.

Assuntos

Poluentes Químicos da Água , Purificação da Água , Desinfecção/métodos , Hidrato de Cloral , Carboidratos , Trialometanos/análise , Purificação da Água/métodos , Poluentes Químicos da Água/análise

RESUMO

Commonly found colonizing the human microbiota, Candida albicans is a microorganism known for its ability to cause infections, mainly in the vulvovaginal region known as vulvovaginal candidiasis (VVC). This pathology is, in fact, one of the main C. albicans clinical manifestations, changing from a colonizer to a pathogen. The increase in VVC cases and limited antifungal therapy make C. albicans an increasingly frequent risk in women's lives, especially in immunocompromised patients, pregnant women and the elderly. Therefore, it is necessary to develop new therapeutic options, especially those involving natural products associated with nanotechnology, such as lycopene and mesoporous silica nanoparticles. From this perspective, this study sought to assess whether lycopene, mesoporous silica nanoparticles and their combination would be an attractive product for the treatment of this serious disease through microbiological in vitro tests and acute toxicity tests in an alternative in vivo model of Galleria mellonella. Although they did not show desirable antifungal activity for VVC therapy, the present study strongly encourages the use of mesoporous silica nanoparticles impregnated with lycopene for the treatment of other human pathologies, since the products evaluated here did not show toxicity in the in vivo test performed, being therefore, a topic to be further explored.

Assuntos

Candidíase Vulvovaginal , Fluconazol , Feminino , Humanos , Gravidez , Idoso , Candida , Dióxido de Silício/uso terapêutico , Licopeno/farmacologia , Licopeno/uso terapêutico , Candidíase Vulvovaginal/tratamento farmacológico , Candidíase Vulvovaginal/microbiologia , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Candida albicans , Testes de Sensibilidade Microbiana

RESUMO

A mononuclear Mn(III) complex of a clickable ligand, [Mn(hbpapn)(H2O)2]ClO4·4.5H2O, where H2hbpapn = 1,3-bis[(2-hydroxybenzyl)(propargyl)amino]propane, has been prepared and fully characterized. The complex catalyzes the dismutation of superoxide employing a Mn(III)/Mn(IV) redox cycle, with catalytic rate constant of 3.9 × 106 M-1 s-1 determined through the nitro blue tetrazolium photoreduction inhibition assay, in aqueous medium of pH 7.8. The alkyne function of the ligand was used for the covalent attachment of the catalyst to azide modified mesoporous silicas with different texture and morphology, through click chemistry. In these materials the catalyst is essentially linked to the inner pore walls, isolated and protected from the external medium. The hybrid materials can be recycled, and retain or improve the superoxide dismutase activity of the free catalyst with the pore size of the solid matrix playing a role on the activity of the catalyst.

Assuntos

Manganês , Dióxido de Silício , Manganês/química , Ligantes , Dióxido de Silício/química , Biomimética , Superóxido Dismutase/química

RESUMO

The degradation of mesoporous silica nanoparticles (MSNs) in the biological milieu due to silica hydrolysis plays a fundamental role for the delivery of encapsulated drugs and therapeutics. However, little is known on the evolution of the pore arrangement in the MSNs in biologically relevant conditions. Small Angle X-ray scattering (SAXS) studies were performed on unmodified and PEGylated MSNs with a MCM-48 pore structure and average sizes of 140 nm, exposed to simulated body fluid solution (SBF) at pH 7.4 for different time intervals from 30 min to 24 h. Experiments were performed with silica concentrations below, at and over 0.14 mg/mL, the saturation concentration of silica in water at physiological temperature. At silica concentrations of 1 mg/mL (oversaturation), unmodified MSNs show variation in interpore distances over 6 h exposure to SBF, remaining constant thereafter. A decrease in radius of gyration is observed over the same time. Mesoporosity and radius of gyration of unmodified MSNs remain then unchanged up to 24 h. PEGylated MSNs at 1 mg/mL concentration show a broader diffraction peak but no change in the position of the peak is observed following 24 h exposure to SBF. PEGylated MSNs at 0.01 mg/mL show no diffraction peaks already after 30 min exposure to SBF, while at 0.14 mg/mL a small diffraction peak is present after 30 min exposure but disappears after 1 h.

RESUMO

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive and behavioral impairment. Curcumin-loaded mesoporous silica nanoparticles (MSN-CCM) can overcome the drawbacks related to the free curcumin (CCM) clinical application, such as water insolubility and low bioavailability, besides acting over the main causes associated to AD. A thermo-responsive hydrogel is an interesting approach for facilitating the administration of the nanosystem via a nasal route, as well as for overcoming mucociliary clearance mechanisms. In light of this, MSN-CCM were dispersed in the hydrogel and evaluated through in vitro and in vivo assays. The MSNs and MSN-CCM were successfully characterized by physicochemical analysis and a high value of the CCM encapsulation efficiency (EE%, 87.70 ± 0.05) was achieved. The designed thermo-responsive hydrogel (HG) was characterized by rheology, texture profile analysis, and ex vivo mucoadhesion, showing excellent mechanical and mucoadhesive properties. Ex vivo permeation studies of MSN-CCM and HG@MSN-CCM showed high permeation values (12.46 ± 1.08 and 28.40 ± 1.88 µg cm-2 of CCM, respectively) in porcine nasal mucosa. In vivo studies performed in a streptozotocin-induced AD model confirmed that HG@MSN-CCM reverted the cognitive deficit in mice, acting as a potential formulation in the treatment of AD.

RESUMO

Pharmaceutical nanotechnology has become a trend with incalculable advantages in the applicability of systems in the controlled, safe and effective release of drugs. Among the nanotechnological nanoparticles, the mesoporous silica nanoparticles stand out, a system with significant biocompatibility, good physical chemical stability, greater surface contact area with desirable and adjustable pore structure. Once developed and well defined, these pores can carry drugs and control their release. However, to create this type of nanoparticle is essencial to use surfactants since they act as pore template. Among the most important surfactants, cetyltrimethylammonium bromide (CTAB) highlights, a quaternary ammonium compound widely used as a surfactant in the synthesis of mesoporous silica nanoparticles (MSNs), hollow mesoporous silica (HMSNs) and core-shell MSNs. However, for achieving good results of drug-loaded pores it is necessary to remove CTAB by extraction techniques, which provides pores formation throughout the silica and the incorporation of molecules. During and after the removal process, it is possible that CTAB residues remains inside the pores, despide several removal processes are described as efficient in the complete removal of surfactants. In turn, the presence of CTAB residues can be advantageous, especially when considering its antimicrobial activity. Meanwhile, it should be noted that the presence of CTAB may present high toxicity risks. This review seeks to explore not only general aspects of the use of CTAB in the synthesis of MSNs, but also to assess its toxicity in prokaryotic and eukaryotic cells, in order to determine whether CTAB residues are acceptable in MSNs that will be used as drug delivery systems for further in vivo and clinical assays.

Assuntos

Nanopartículas , Dióxido de Silício , Cetrimônio , Porosidade , Tensoativos

RESUMO

Neurodegenerative diseases (NDs) are considered public health problem characterized by neural loss causing cognitive and behavioral impairments. It is currently possible to use drugs capable of controlling the symptoms caused by these diseases. However, treatment is not able to prevent neural loss. In addition, poor solubility, low bioavailability due to the inability for crossing the blood-brain barrier (BBB) are described as the main limitations of the treatment. Nanotechnology involves the development of nanoscale drug delivery systems and they have been employed to optimize therapeutics face to several diseases treatment. In light of this, this review describes the highlights on the fabrication of nanotechnology-based drug delivery systems emphasizing mesoporous silica, gold and silver nanoparticles (MSNs, AuNPs and AgNPs, respectively) and their biological behavior for the treatment of Alzheimer's and Parkinson diseases (ADs and PDs, respectively).

Assuntos

Nanopartículas Metálicas , Nanopartículas , Doenças Neurodegenerativas , Sistemas de Liberação de Medicamentos , Ouro/uso terapêutico , Humanos , Doenças Neurodegenerativas/tratamento farmacológico , Porosidade , Dióxido de Silício/uso terapêutico , Prata

RESUMO

Mesoporous silica nanoparticles, with and without the inclusion of a magnetic core, were hydrothermally synthesized and employed as carrier of the antibiotic norfloxacin (NFX). The antibiotic-loaded materials were prepared by wet impregnation. Differences in drug content (and in further release profile) were directly related to changes in surface area, particle aggregation and hydrophobicity of the solids. The kinetics of NFX release has been studied in batch experiments. In all cases, more than 55% of the antibiotic was quickly desorbed during the first 5 min due to the localization of NFX on the external surface of the nanoparticles. The rest of the drug (situated inside the mesopores) was released through a diffusion-controlled transport and the rate was strongly dependent of the pH, reaching its minimum value at neutral pH. The calculated activation energy confirmed that the release was controlled by a diffusion process. Breaking of H-bonds and electrostatic and hydrophobic interactions appear to be responsible for NFX desorption from the solid surface. Such interactions increase, however, the thermal stability of the drug when the NFX and the carriers are combined. The antimicrobial activities of the drug loaded nanoparticles and the free antibiotic were compared and discussed.

Assuntos

Nanopartículas , Dióxido de Silício , Antibacterianos/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Excipientes , Nanopartículas/química , Norfloxacino/química , Tamanho da Partícula , Preparações Farmacêuticas , Porosidade , Dióxido de Silício/química , Eletricidade Estática

RESUMO

Beef is a fundamental part of the human diet, but it is highly susceptible to microbiological and physicochemical deterioration which decrease its shelf life. This work aimed to formulate an active edible film (AEF) incorporated with amino-functionalized mesoporous silica nanoparticles (A-MSN) loaded with Mexican oregano (Lippia graveolens Kunth) essential oil (OEO) and to evaluate its effect as a coating on fresh beef quality during refrigerated storage. The AEF was based on amaranth protein isolate (API) and chitosan (CH) (4:1, w/w), to which OEO emulsified or encapsulated in A-MSN was added. The tensile strength (36.91 ± 1.37 MPa), Young's modulus (1354.80 ± 64.6 MPa), and elongation (4.71%) parameters of AEF made it comparable with synthetic films. The antimicrobial activity of AEF against E. coli O157:H7 was improved by adding 9% (w/w) encapsulated OEO, and interactions of glycerol and A-MSN with the polymeric matrix were observed by FT-IR spectroscopy. In fresh beef, after 42 days, AEF reduced the population growth (Log CFU/cm2, relative to uncoated fresh beef) of Brochothrix thermosphacta (5.5), Escherichia coli (3.5), Pseudomonas spp. (2.8), and aerobic mesophilic bacteria (6.8). After 21 days, odor acceptability of coated fresh beef was improved, thus, enlarging the shelf life of the beef and demonstrating the preservation capacity of this film.

Assuntos

Filmes Comestíveis , Lippia , Nanopartículas , Óleos Voláteis , Origanum , Animais , Bovinos , Humanos , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Origanum/química , Lippia/química , Conservação de Alimentos/métodos , Microbiologia de Alimentos , Escherichia coli , Espectroscopia de Infravermelho com Transformada de Fourier , Embalagem de Alimentos/métodos

RESUMO

The alliance between 3D printing and nanomaterials brings versatile properties to pharmaceuticals, but few studies have explored this approach in the development of skin delivery formulations. In this study, clobetasol propionate (CP) was loaded (about 25% w/w) in mesoporous silica nanomaterial (MSN) to formulate novel bioadhesive and hydrophilic skin delivery films composed of pectin (5% w/v) and carboxymethylcellulose (5% w/v) by 3D printing. As a hydrophobic model drug, CP was encapsulated in MSN at a 3:1 (w/w) ratio, resulting in a decrease of CP crystallinity and an increase of its dissolution efficiency after 72 h (65.70 ± 6.52%) as compared to CP dispersion (40.79 ± 4.75%), explained by its partial change to an amorphous form. The CP-loaded MSN was incorporated in an innovative hydrophilic 3D-printable ink composed of carboxymethylcellulose and pectin (1:1, w/w), which showed high tensile strength (3.613 ± 0.38 N, a homogenous drug dose (0.48 ± 0.032 mg/g per film) and complete CP release after 10 h. Moreover, the presence of pectin in the ink increased the skin adhesion of the films (work of adhesion of 782 ± 105 mN·mm). Therefore, the alliance between MSN and the novel printable ink composed of carboxymethylcellulose and pectin represents a new platform for the production of 3D-printed bioadhesive films, opening a new era in the development of skin delivery systems.

RESUMO

This work proposes a novel technology for environmental remediation based on mesoporous silica spheres, which were successfully synthesized by the solvothermal method using the cetyltrimethylammonium bromide as a structuring agent. The adsorbent was designed to remove cationic dyes at strong acidic conditions. The surface was modified by a careful thermal treatment aiming at the condensation of silanol to siloxane groups. The adsorbent was characterized by XRD, SEM, FTIR, N2 adsorption/desorption and the equilibrium technique to determine the pHpzc. The kinetic of the adsorption followed a pseudo-second-order model and the process was ruled by physical forces. The isotherms were fitted to Freundlich and Temkin models, indicating that the physisorption occurred with multilayer formation, with the interaction adsorbate-adsorbate being relevant to the whole process. The adsorption capacity was approximately 60 mg g-1 and the adsorbents performance in the fast-contact system showed removal of 65%wt. of a 93 mg L-1 methylene blue (MB) solution in a single application.

Assuntos

Azul de Metileno , Poluentes Químicos da Água , Adsorção , Dióxido de Silício , Água

RESUMO

Routine immunization against diphtheria and tetanus has drastically reduced the incidence of these diseases worldwide. Anti-diphtheria/tetanus vaccine has in general aluminum salt as adjuvant in its formulation that can produce several adverse effects. There is a growing interest in developing new adjuvants. In this study, we evaluated the efficiency of SBA-15 as an adjuvant in subcutaneous immunization in mice with diphtheria (dANA) and tetanus (tANA) anatoxins as well as with the mixture of them (dtANA). The tANA molecules and their encapsulation in SBA-15 were characterized using Small-Angle X-ray Scattering (SAXS), Dynamical Light Scattering (DLS), Nitrogen Adsorption Isotherm (NAI), Conventional Circular Dichroism (CD)/Synchrotron Radiation Circular Dichroism (SRCD) Spectroscopy, and Tryptophan Fluorescence Spectroscopy (FS). The primary and secondary antibody response elicited by subcutaneous immunization of High (HIII) and Low (LIII) antibody responder mice with dANA, tANA, or dtANA encapsulated in the SBA-15 were determined. We demonstrated that SBA-15 increases the immunogenicity of dANA and tANA antigens, especially when administered in combination. We also verified that SBA-15 modulates the antibody response of LIII mice, turning them into high antibody responder. Thus, these results suggest that SBA-15 may be an effective adjuvant for different vaccine formulations.

RESUMO

Innovative technologies have been designed to improve efficacy and safety of chemical UV filters. Encapsulation can enhance efficacy and reduce transdermal permeation and systemic exposure. The aims of this work were (i) to determine the cutaneous biodistribution of avobenzone (AVO), oxybenzone (OXY), and octyl methoxycinnamate (OMC) incorporated in mesoporous silica SBA-15 and (ii) to perform preclinical (in vitro) and (iii) clinical safety studies to demonstrate their innocuity and to evaluate sun protection factor (SPF) in humans. Skin penetration studies showed that deposition of OXY and AVO in porcine and human skin after application of stick formulation with incorporated filters (stick incorporated filters) was significantly lower than from a marketed (non-encapsulated) stick. Cutaneous deposition and transdermal permeation of OXY in and across human skin were 3.8-and 13.4- fold lower, respectively, after application of stick entrapped filters. Biodistribution results showed that encapsulation in SBA-15 decreased AVO and OXY penetration reaching porcine and human dermis. Greater deposition (and permeation) of OXY in porcine skin than in human skin, pointed to the role of follicular transport. Stick incorporated filters had good biocompatibility in vivo and safety profiles, even under sun-exposed conditions. Entrapment of UV filters improved the SPF by 26% and produced the same SPF profile as a marketed stick. Overall, the results showed that SBA-15 enabled safety and efficacy of UV filters to be increased.

Assuntos

Benzofenonas/farmacocinética , Cinamatos/farmacocinética , Propiofenonas/farmacocinética , Dióxido de Silício/farmacologia , Distribuição Tecidual , Administração Cutânea , Animais , Composição de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos , Humanos , Filtros Microporos , Absorção Cutânea , Fator de Proteção Solar , Protetores Solares/farmacocinética , Suínos

RESUMO

Mesoporous silica has unique properties such as controllable mesoporous structure and size, good biocompatibility, high specific surface area, and large pore volume. For that reason, this material has been broadly functionalized for biomedical applications, such as optical imaging, magnetic resonance imaging (MRI), positron emission tomography (PET), computed tomography (CT), ultrasound imaging, and widely employed as drug delivery systems. In this study, we synthesized fiber-type mesoporous silica capped with hydroxyapatite (ordered SiO2-CaO-P2O5 mesoporous silica). Its biological activity was evaluated through a cellular and molecular approach using HUVEC cell culture. Two distinct methodologies have produced the ordered SiO2-CaO-P2O5 mesoporous silica: (i) two-step Ca-doped silica matrix followed by hydroxyapatite crystallization inside the Ca-doped silica matrix and (ii) one-step Ca-doped silica matrix formed with the hydroxyapatite crystallization. Further analysis included: elemental analysis, transmission, scanning electron microscopy images, Small and Wide-Angle X-ray Diffraction analysis, Fourier Transform Infrared, and in vitro assays with HUVEC (cytotoxicity and immunoblotting). The hydroxyapatite capping methodology significantly affected the original mesoporous material structure. Furthermore, no cellular or molecular effect has been observed. The promising results presented here suggest that the one-step method to obtain hydroxyapatite capped mesoporous silica was effective, also demonstrating that this material has potential in biomedical applications.