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Mitochondria is a subcellular organelle involved in the pathogenesis of cellular stress, immune responses, differentiation, metabolic disorders, aging, and death by regulating process of fission, fusion, mitophagy, and transport. However, an increased interest in mitochondria as powerhouse for ATP production, the mechanisms of mitochondria-mediated cellular dysfunction in response to hormonal interaction remains unknown. Mitochondrial matrix contains chaperones and proteases that regulate intrinsic apoptosis pathway through pro-apoptotic Bcl-2 family's proteins Bax/Bak, and Cyt C release, and induces caspase-dependent and independent cells death. Energy and growth regulators such as thyroid hormones have profound effect on mitochondrial inner membrane protein and lipid compositions, ATP production by regulating oxidative phosphorylation system. Mitochondria contain cholesterol side-chain cleavage enzyme, P450scc, ferredoxin, and ferredoxin reductase providing an essential site for steroid hormones biosynthesis. In line with this, neurohormones such as oxytocin, vasopressin, and melatonin are correlated with mitochondrial integrity, displaying therapeutic implications for inflammatory and immune responses. Melatonin's also displayed protective role against oxidative stress and mitochondrial synthesis of ROS, suggesting a defense mechanism against aging-related diseases. An imbalance in mitochondrial bioenergetics can cause neurodegenerative disorders, cardiovascular diseases, and cancers. Hormone-induced PGC-1α stimulates mitochondrial biogenesis via activation of NRF1 and NRF2, which in turn triggers mtTFA in brown adipose and cardiac myocytes. Mitochondria can be transferred through cells merging, exosome-mediated transfer, and tunneling through nanotubes. By delineating the underlying molecular mechanism of hormonal mitochondrial interaction, this study reviews the dynamics mechanisms of mitochondria and its effects on cellular level, health, diseases, and therapeutic strategies targeting mitochondrial diseases.
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2-Phosphonobutane-1,2,4,-tricarboxylic acid (PBTC) is an orthophosphate compound widely used as an antiscalant chemical and corrosion inhibitor in manufacturing. However, PBTC poses persistent environmental concerns due to its stability and resistance to conventional water treatment. In addressing the issues of PBTC in aquatic systems, Al-based metal-organic frameworks (MOFs) have been developed and applied as sustainable adsorbents. The materials are synthesized from terephthalic acid (TPA) linkers derived from upcycling products of post-consumer polyethylene terephthalate (PET) bottles. The PET-derived linker was prepared using alkaline hydrolysis followed by acidification and employed in forming MIL-53 (Al), with a comparative assessment against the corresponding MOFs made from commercial-grade TPA. The structures and properties of the materials were characterized with microscopic and spectroscopic methods. The synthesized adsorbents achieved a phosphate adsorption capacity of 826 mg/g at pH 5, with kinetics fitting a pseudo-second-order model and isotherm patterns aligning with Langmuir, Freundlich, and Sips models, indicative of diverse adsorption on heterogeneous surfaces. The results highlight the role of electrostatic interactions and hydrogen bonding mechanisms in PBTC adsorption. The eco-friendly materials with high adsorption performance offer an innovative route for sustainable waste management and water purification.
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We propose a new strategy using a sandwich approach for the detection of two HF biomarkers: tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10). For this purpose, magnetic nanoparticles (MNPs) (MNPs@aminodextran) were biofunctionalized with monoclonal antibodies (mAbs) using bis (sulfosuccinimidyl) suberate (BS3) as a cross-linker for the pre-concentration of two biomarkers (TNF-α and IL-10). In addition, our ISFETs were biofunctionalized with polyclonal antibodies (pAbs) (TNF-α and IL-10). The biorecognition between pAbs immobilized on the ISFET and the pre-concentrate antigen (Ag) on MNPs was monitored using electrochemical impedance spectroscopy (EIS). Our developed ImmunoFET showed a low detection limit (0.03 pg/mL) toward our target analyte when compared to previously published electrochemical immunosensors. It showed a higher sensitivity than for other HF biomarkers. Finally, the standard addition method was used to determine the unknown concentration in artificial saliva. The results matched with the expected values well.
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Leptospirosis is a serious health problem in tropical areas; thus, animals shed leptospires in the environment. Humans are accidental hosts infected through exposure to contaminating bacteria in the environment. One health strategy can be applied to protect and eliminate leptospirosis because this cooperates and coordinates activities between doctors, veterinarians, and ecologists. However, conventional methods still have limitations. Therefore, the main challenges of leptospirosis control are the high sensing of detection methods to screen and control the pathogens. Interestingly, nano sensing combined with a leptospirosis detection approach can increase the sensitivity and eliminate some limitations. This article reviews nanomaterial development for an advanced leptospirosis detection method, e.g., latex beads-based agglutination test, magnetic nanoparticles enrichment, and gold-nanoparticles-based immunochromatographic assay. Thus, nanomaterials can be functionalized with biomolecules or sensing molecules utilized in various mechanisms such as biosensors. Over the last decade, many biosensors have been developed for Leptospira spp. pathogen and others. The evolution of biosensors for leptospirosis detection was designed for high efficiency and might be an alternative tool. In addition, the high-sensing fabrications are useful for leptospires screening in very low levels, for example, soil or water from the environment.
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Leptospira , Leptospirose , Nanopartículas , Humanos , Animais , Leptospirose/diagnóstico , Leptospirose/prevenção & controle , Leptospirose/microbiologia , Leptospirose/veterinária , Testes de Fixação do Látex/veterináriaRESUMO
Cyclodextrins (CDs) are known for their ability to extract lipid components from synthetic and biological membranes and therefore to induce an increase of membrane permeability. However, the effect of cholesterol (CHOL) content in the membrane on the CD permeabilizing effect was not considered yet. Given that an increase in CHOL content reduces the membrane permeability, the aim of this work was to reveal how CHOL would modulate the CDs effect on the membrane. Hence, liposomes made of dipalmitoyl phosphatidylcholine (DPPC) and various CHOL contents (DPPC/CHOL 100:10, 100:25, 100:50, and 100:100) encapsulating the hydrophilic fluorophore, sulforhodamine B (SRB), were prepared and exposed to the native CDs (α-CD, ß-CD, γ-CD) and four ß-CD derivatives: the randomly methylated-ß-CD (RAMEB), the low methylated-ß-CD (CRYSMEB), the hydroxypropyl-ß-CD (HP-ß-CD) and the sulfobutyl ether-ß-CD (SBE-ß-CD) at different CD/DPPC molar ratios (1:1, 10:1, and 100:1). The membrane permeability was monitored following the release of SRB with time. The results demonstrated that the CDs effect on the membrane depends on the CD type, CD concentration, and membrane CHOL content. The investigated CDs exhibited an instantaneous permeabilizing effect promoting vesicle leakage of SRB from the various membranes; this effect increased with CDs concentration. Among the studied CDs, α-CD, ß-CD, and RAMEB were the most permeabilizing CDs on the different membranes. Similar modifications of SRB release from the various liposomal formulations were obtained with HP-ß-CD, CRYSMEB, and SBE-ß-CD. γ-CD was the less potent CD in affecting the membrane permeability. The CDs effect also depended on the CHOL content: at the CD/DPPC molar ratio (100:1), RAMEB and ß-CD considerably permeabilized the membrane of high CHOL content (50%, 100%) while the remaining CDs showed a decreasing permeabilizing effect upon CHOL content membrane increase.
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Worldwide, colon cancer is the third most frequent malignancy and the second most common cause of death. Although it can strike anybody at any age, colon cancer mostly affects the elderly. Small, non-cancerous cell clusters inside the colon, commonly known as polyps, are typically where colon cancer growth starts. But over time, if left untreated, these benign polyps may develop into malignant tissues and develop into colon cancer. For the diagnosis of colon cancer, with routine inspection of the colon region for polyps, several techniques, including colonoscopy and cancer scanning, are used. In the case identifying the polyps in the colon area, efforts are being taken to surgically remove the polyps as quickly as possible before they become malignant. If the polyps become malignant, then colon cancer treatment strategies, such as surgery, chemotherapy, targeted therapy, and immunotherapy, are applied to the patients. Despite the recent improvements in diagnosis and prognosis, the treatment of colorectal cancer (CRC) remains a challenging task. The objective of this review was to discuss how CRC is initiated, and its various developmental stages, pathophysiology, and risk factors, and also to explore the current state of colorectal cancer diagnosis and treatment, as well as recent advancements in the field, such as new screening methods and targeted therapies. We examined the limitations of current methods and discussed the ongoing need for research and development in this area. While this topic may be serious and complex, we hope to engage and inform our audience on this important issue.
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In this paper, a microconductometric sensor has been designed, based on a chitosan composite including alcohol dehydrogenase-and its cofactor-and gold nanoparticles, and was calibrated by differential measurements in the headspace of aqueous solutions of ethanol. The role of gold nanoparticles (GNPs) was crucial in improving the analytical performance of the ethanol sensor in terms of response time, sensitivity, selectivity, and reproducibility. The response time was reduced to 10 s, compared to 21 s without GNPs. The sensitivity was 416 µS/cm (v/v%)-1 which is 11.3 times higher than without GNPs. The selectivity factor versus methanol was 8.3, three times higher than without GNPs. The relative standard deviation (RSD) obtained with the same sensor was 2%, whereas it was found to be 12% without GNPs. When the air from the operator's mouth was analyzed just after rinsing with an antiseptic mouthwash, the ethanol content was very high (3.5 v/v%). The background level was reached only after rinsing with water.
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Microemulsions are novel drug delivery systems that have garnered significant attention in the pharmaceutical research field. These systems possess several desirable characteristics, such as transparency and thermodynamic stability, which make them suitable for delivering both hydrophilic and hydrophobic drugs. In this comprehensive review, we aim to explore different aspects related to the formulation, characterization, and applications of microemulsions, with a particular emphasis on their potential for cutaneous drug delivery. Microemulsions have shown great promise in overcoming bioavailability concerns and enabling sustained drug delivery. Thus, it is crucial to have a thorough understanding of their formulation and characterization in order to optimize their effectiveness and safety. This review will delve into the different types of microemulsions, their composition, and the factors that affect their stability. Furthermore, the potential of microemulsions as drug delivery systems for skin applications will be discussed. Overall, this review will provide valuable insights into the advantages of microemulsions as drug delivery systems and their potential for improving cutaneous drug delivery.
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Traditional cancer diagnosis has been aided by the application of nanoparticles (NPs), which have made the process easier and faster. NPs possess exceptional properties such as a larger surface area, higher volume proportion, and better targeting capabilities. Additionally, their low toxic effect on healthy cells enhances their bioavailability and t-half by allowing them to functionally penetrate the fenestration of epithelium and tissues. These particles have attracted attention in multidisciplinary areas, making them the most promising materials in many biomedical applications, especially in the treatment and diagnosis of various diseases. Today, many drugs are presented or coated with nanoparticles for the direct targeting of tumors or diseased organs without harming normal tissues/cells. Many types of nanoparticles, such as metallic, magnetic, polymeric, metal oxide, quantum dots, graphene, fullerene, liposomes, carbon nanotubes, and dendrimers, have potential applications in cancer treatment and diagnosis. In many studies, nanoparticles have been reported to show intrinsic anticancer activity due to their antioxidant action and cause an inhibitory effect on the growth of tumors. Moreover, nanoparticles can facilitate the controlled release of drugs and increase drug release efficiency with fewer side effects. Nanomaterials such as microbubbles are used as molecular imaging agents for ultrasound imaging. This review discusses the various types of nanoparticles that are commonly used in cancer diagnosis and treatment.
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Encapsulation is the way to wrap or coat one substance as a core inside another tiny substance known as a shell at micro and nano scale for protecting the active ingredients from the exterior environment. A lot of active substances, such as flavours, enzymes, drugs, pesticides, vitamins, in addition to catalysts being effectively encapsulated within capsules consisting of different natural as well as synthetic polymers comprising poly(methacrylate), poly(ethylene glycol), cellulose, poly(lactide), poly(styrene), gelatine, poly(lactide-co-glycolide)s, and acacia. The developed capsules release the enclosed substance conveniently and in time through numerous mechanisms, reliant on the ultimate use of final products. Such technology is important for several fields counting food, pharmaceutical, cosmetics, agriculture, and textile industries. The present review focuses on the most important and high-efficiency methods for manufacturing micro/nanocapsules and their several applications in our life.
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Nanocápsulas , Polímeros , PolietilenoglicóisRESUMO
INTRODUCTION: Cancer has one of the highest mortality rates globally. The traditional therapies used to treat cancer have harmful adverse effects. Considering these facts, researchers have explored new therapeutic possibilities with enhanced benefits. Nanoparticle development for cancer detection, in addition to therapy, has shown substantial progress over the past few years. AREA COVERED: Herein, the latest research regarding cancer treatment employing magnetic nanoparticles (MNPs) in chemo-, immuno-, gene-, and radiotherapy along with hyperthermia is summarized, in addition to their physio-chemical features, advantages, and limitations for clinical translation have also been discussed. EXPERT OPINION: MNPs are being extensively investigated and developed into effective modules for cancer therapy. They are highly functional tools aimed at cancer therapy owing to their excellent superparamagnetic, chemical, biocompatible, physical, and biodegradable properties.
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Hipertermia Induzida , Nanopartículas de Magnetita , Nanopartículas , Neoplasias , Humanos , Nanopartículas de Magnetita/uso terapêutico , Nanopartículas de Magnetita/química , Neoplasias/tratamento farmacológico , Magnetismo , Terapia CombinadaRESUMO
Nanotechnology has ultimately come into the domain of drug delivery. Nanosystems for delivery of drugs are promptly emerging science utilizing different nanoparticles as carriers. Biocompatible and stable nanocarriers are novel diagnosis tools or therapy agents for explicitly targeting locates with controllable way. Nanocarriers propose numerous advantages to treat diseases via site-specific as well as targeted delivery of particular therapeutics. In recent times, there are number of outstanding nanocarriers use to deliver bio-, chemo-, or immuno- therapeutic agents to obtain effectual therapeutic reactions and to minimalize unwanted adverse-effects. Nanoparticles possess remarkable potential for active drug delivery. Moreover, conjugation of drugs with nanocarriers protects drugs from metabolic or chemical modifications, through their way to targeted cells and hence increased their bioavailability. In this review, various systems integrated with different types of nanocarriers (inorganic. organic, quantum dots, and carbon nanotubes) having different compositions, physical and chemical properties have been discussed for drug delivery applications.
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Nanopartículas , Nanotubos de Carbono , Nanotubos de Carbono/química , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Nanotecnologia , Preparações Farmacêuticas , Portadores de Fármacos/químicaRESUMO
Heart failure (HF) is a chronic cardiovascular disease that represents main cause of mortality worldwide, particularly for elderly. N-terminal pro-brain natriuretic peptide (NT-proBNP) was identified as the gold standard biomarker for HF diagnosis and therapy monitoring. Presently, saliva analysis represents an emerging and powerful tool for clinical applications and electrochemical immunosensors have shown their potential in Healthcare applications as selective and reliable systems for detecting clinical biomarkers. This work presents the detection of NT-proBNP in saliva samples by an immunologically modified Field effect Transistor (IMFET). TESUD ((11-triethoxysilyl) undecanal) was used as cross-linker to immobilise anti-NT-proBNP antibody onto the device. Our IMFET that was then tested in different matrices (e.g. phosphate buffered saline (PBS), artificial saliva and human saliva) using electrochemical impedance spectroscopy (EIS), and it resulted selective to NT-proBNP with good sensitivity (detection limit of 0.02 pg/mL) and a wide linear range (0.02-1 pg/mL and 0.5-20 pg/mL). Finally, NT-proBNP concentration in ten saliva samples was determined by performing the standard addition method. An enzyme-linked immunosorbent assay was used for confirming IMFET results, highlighting both IMFET accuracy (analyte recovery of 99 ± 8%) and precision (coefficient of variation always <10%), and supporting the suitability of the device for determining salivary NT-proBNP.
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Técnicas Biossensoriais , Insuficiência Cardíaca , Idoso , Humanos , Biomarcadores , Insuficiência Cardíaca/diagnóstico , Imunoensaio , Peptídeo Natriurético Encefálico , Fragmentos de Peptídeos , Fosfatos , Saliva , Saliva Artificial , Volume Sistólico , Técnicas EletroquímicasRESUMO
The interactions between sodium caseinate (CAS) and two natural aldehydes (trans-cinnamaldehyde (TC) and citral) were studied by evaluating oil/water (O/W) interfacial and fluorescence quenching properties. A small amount of TC in the oily phase resulted in lower O/W interfacial tension (9.12 mN/m). Particularly, the use of TC developed a stronger interface with higher elastic moduli (â¼16.21 mN/m). This was supported by the fluorescence measurements: the quenching effect of TC on CAS was more pronounced than that of citral. Kinetic analysis indicated that both dynamic and static quenching occurs. The large binding constant (1.78 × 105 M-1) at 25 °C suggests that TC has strong affinity for CAS. Meanwhile, this binding process seemed to be spontaneous and driven by hydrogen bond formation with unfavorable conformational changes. This work would provide guidance for using the binding properties of natural aldehydes to enhance the interfacial properties of proteins.
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Acroleína , Caseínas , Acroleína/análogos & derivados , Monoterpenos Acíclicos , Caseínas/química , Cinética , ReologiaRESUMO
Stimulus-responsive nanoparticles are among the most utilized nanoscale materials in biomedical applications. As these nanoparticles exhibit a manipulable response to a particular stimulus, such as pH, heat, and organic solvent, they are potential signalling units in diagnostic assays. This study aims to enhance the limit of detection and reduce the turnaround time of magnetic nanoparticle polymerase chain reaction (PCR) enzyme-linked gene assay (MELGA), an advanced PCR-based technique termed the solvent-sensitive nanoparticle (SSNP)-enhanced PCR assay. This technique was proposed to detect pathogenic enterotoxigenic Escherichia coli (ETEC) through applying stimulus-responsive nanoparticles. The SSNPs were elaborated with three main components, including mesoporous silica nanoparticles as a structural unit, organic dye (Nile red) as a payload, and the corresponding organic solvent-sensitive polymer shell as "gatekeeper" (poly(maleic anhydride-alt-methyl vinyl ether, PMAMVE). A suitable organic solvent capable of inducing polymer swelling and dye dissolution was investigated by considering a solubility parameter. Using ethanol, the encapsulated Nile red can diffuse out of the SSNPs faster than other solvents and reach a constant concentration within 15 min. For the PCR inhibition study, various SSNPs concentrations (10-30 µg/reaction) were mixed with the ETEC gene and PCR reagent. The results showed that the particles in this concentration range did not inhibit PCR. By comparing the efficacy of conventional PCR, MELGA, and SSNP-enhanced PCR assay, the proposed technique showed a better detection limit than that of PCR, whereas that of MELGA was the lowest. Moreover, compared to MELGA or conventional PCR, this technique provided remarkably faster results in the postamplification process.
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Escherichia coli Enterotoxigênica , Nanopartículas , Solventes , Escherichia coli Enterotoxigênica/genética , Reação em Cadeia da Polimerase , PolímerosRESUMO
Emulsions can be easily destabilized under various conditions during preparation and storage. Therefore, it is necessary to understand the factors that influence the stability of emulsions, which is essential for their subsequent studies. Sodium caseinate (CAS) is a well-used nutritional and functional ingredient in emulsion preparation due to its good solubility and emulsifying properties. CAS-stabilized emulsions can be considered good food emulsion delivery systems, but their applications are still limited under certain conditions due to their instability to creaming and aggregation. Therefore, the purpose of this review is to provide a complete overview of how different environmental stresses and processing conditions affect the stability of CAS-stabilized emulsions and how to improve their stability. Initially, the general properties of CAS as emulsifiers and the characterization of CAS-stabilized oil-in-water (O/W) emulsions were summarized. Second, the major instability mechanisms that operate in CAS-stabilized emulsions were presented. Furthermore, the general factors such as pH, emulsifier concentration, ionic strength, oxidation, and processing conditions, affecting the stability of CAS-stabilized O/W emulsion, were discussed. On this basis, the commonly used methods for evaluating emulsion stability are introduced. Finally, state-of-the-art strategies to improve CAS-based emulsion stability are also described and summarized. This review is expected to provide a theoretical basis for the future applications of CAS in food emulsions.
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Caseínas , Emulsificantes , Emulsões/química , Caseínas/química , Emulsificantes/química , Oxirredução , AlimentosRESUMO
In this research work, polymer blends of poly-lactic acid (PLA)/ethylene vinyl acetate (EVA) were prepared as the drug carrier materials for a bi-layer drug-loaded coating film for coronary stents. Different optimum compositions of blends were prepared by using an intense mixer. Then, the blends were hot-pressed and later cold-pressed to prepare for films of different thickness. The changes in weight, surface analysis and biodegradability with increasing time were studied using Scanning electron microscopy (SEM), weight loss and biodegradability tests. The mechanical and thermal properties of drug-loaded films were studied through universal testing machine (UTM) and thermo-gravimetric analysis (TGA). The effects of PLA, EVA and drug contents on in-vitro drug contents were investigated through the Ultraviolet-Visible Spectroscopy (UV-VIS) chemical analysis technique. The results obtained clearly showed that the addition of PLA promoted the unleashing of the drug whereas the addition of EVA nearly did not have the same affect. The mechanical properties of these various films can be tuned by adjusting the contents of blend parts. The factors affecting the unleashing of the drug became a serious matter of concern in evaluating the performance of bio-resorbable drug eluting stents. As a result, today's chemical blends may be useful drug carrier materials for drug-loaded tube coatings capable delivering purgative drug in an incredibly tunable and regulated manner.
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Microneedle patches (MNPs) are one of the emerging approaches for drug delivery involving minimal invasion and improved skin penetration of macro- and micro-entities. Herein, we report dissolvable microneedle patches (dMNPs) as a novel tool for better systemic delivery of Simvastatin in the management of hypocholesteremia. Thiolated chitosan (TC), polyvinyl pyrolidone (PVP) and polyvinyl alcohol (PVA) were employed in the development of dMNPs. Developed patches were characterized through SEM, FTIR, DSC, TGA, PXRD, dissolution testing, tensile strength, elongation (%), skin irritation studies, moisture content and pharmacokinetic evaluation. dMNP F26 exhibited excellent tensile strength (9.85 MPa), penetration potential (~700 µm), moisture content (5.95%), elongation (35.54%) and Simvastatin release of 77.92%. Pharmacokinetic properties were also improved, i.e., Cmax 1.97 µg/mL, tmax 9 h, MRT 19.9 h and AUC 46.24 µg·h/mL as compared to Simvastatin solution displaying Cmax 2.55 µg/mL, tmax 3 h, MRT 5.91 h and AUC 14.20 µg·h/mL thus confirming higher and improved bioavailability. Kinetic modelling revealed zero order as the best fit model based on regression coefficient. Histopathological findings proved the biocompatibility of the developed dMNPs.
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The impact of individual component, i.e., plant extract (Plagiochasma rupestre), biosynthesized silver nanoparticles (AgNPs), and healing clay (bentonite) as antimicrobial agent is reported but their combined effect as a ternary system is a new approach. This study is aimed at investigating the impact of the proposed ternary system against selected human pathogens. AgNPs were synthesized by using Plagiochasma rupestre extract (aqueous) as reducing agent and neutral polymer (PVP) as stabilizer. The morphology, size, and structural properties of synthesized AgNPs were determined with XRD and SEM analysis which showed spherical monomodal particles with an average particle size of 25.5 nm. The antibacterial and antifungal activities of the individual and nanoternary system were investigated. The phytochemical screening of plant extract showed the presence of alkaloids, flavonoids, phenol, and glycosides in methanol extract as compare to aqueous and acetone extract. The antimicrobial activities of crude extracts of Plagiochasma rupestre with AgNPs and bentonite clay were studied as an appropriate candidate for treatment of microbial infections, especially bacterial and fungal diseases. The antioxidant activity of Plagiochasma rupestre aqueous extract and nanoparticles was assessed by (DPPH) free radical, and absorbance was checked at 517 nm. Crude extract has inhibitory effect towards bacteria and fungi, and bentonite clay also showed some degree of antimicrobial resistance. Strategy can be efficiently applied for future engineering and medical. The nanoternary systems showed 3 and 3.5 times higher antibacterial and antifungal activity, respectively, in comparison to Plagiochasma rupestre and bentonite clay, individually.
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Anti-Infecciosos , Nanopartículas Metálicas , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antifúngicos/farmacologia , Bactérias , Bentonita/farmacologia , Argila , Humanos , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Prata/química , Prata/farmacologiaRESUMO
Stimuli-responsive controlled delivery systems are of interest for preventing premature leakages and ensuring precise releases of active compounds at target sites. In this study, porous biodegradable micro/nanoparticles embedded with thermoresponsive gatekeepers are designed and developed based on Eudragit RS100 (PNIPAM@RS100) and poly(N-isopropylacrylamide) via a double emulsion solvent evaporation technique. The effect of initiator types on the polymerization of NIPAM monomer/methylene-bis-acrylamide (MBA) crosslinker was investigated at 60 °C for thermal initiators and ambient temperature for redox initiators. The crosslinked PNIPAM plays a key role as thermal-triggered gatekeepers with high loading efficiency and precise release of a model active compound, Nile Blue A (NB). Below the volume phase transition temperature (TVPT), the gatekeepers possess a swollen conformation to block the pores and store NB within the cavities. Above its TVPT, the chains rearrange, allowing gate opening and a rapid and constant release rate of the compound until completion. A precise "on-off" switchable release efficiency of PNIPAM@RS100 was demonstrated by changing the temperatures to 4 and 40 °C. The materials are a promising candidate for controlled drug delivery systems with a precise and easy triggering mechanism at the body temperature for effective treatments.