Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 68
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Crit Care Med ; 52(7): 1113-1126, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38236075

ABSTRACT

OBJECTIVES: To provide a narrative review of hospital violence (HV) and its impact on critical care clinicians. DATA SOURCES: Detailed search strategy using PubMed and OVID Medline for English language articles describing HV, risk factors, precipitating events, consequences, and mitigation strategies. STUDY SELECTION: Studies that specifically addressed HV involving critical care medicine clinicians or their practice settings were selected. The time frame was limited to the last 15 years to enhance relevance to current practice. DATA EXTRACTION: Relevant descriptions or studies were reviewed, and abstracted data were parsed by setting, clinician type, location, social media events, impact, outcomes, and responses (agency, facility, health system, individual). DATA SYNTHESIS: HV is globally prevalent, especially in complex care environments, and correlates with a variety of factors including ICU stay duration, conflict, and has recently expanded to out-of-hospital occurrences; online violence as well as stalking is increasingly prevalent. An overlap with violent extremism and terrorism that impacts healthcare facilities and clinicians is similarly relevant. A number of approaches can reduce HV occurrence including, most notably, conflict management training, communication initiatives, and visitor flow and access management practices. Rescue training for HV occurrences seems prudent. CONCLUSIONS: HV is a global problem that impacts clinicians and imperils patient care. Specific initiatives to reduce HV drivers include individual training and system-wide adaptations. Future methods to identify potential perpetrators may leverage machine learning/augmented intelligence approaches.


Subject(s)
Critical Care , Humans , Critical Care/methods , Intensive Care Units , Risk Factors , Workplace Violence/prevention & control , Workplace Violence/statistics & numerical data , Violence/prevention & control
2.
J Med Internet Res ; 25: e44030, 2023 05 04.
Article in English | MEDLINE | ID: mdl-37140973

ABSTRACT

The use of artificial intelligence (AI) and big data in medicine has increased in recent years. Indeed, the use of AI in mobile health (mHealth) apps could considerably assist both individuals and health care professionals in the prevention and management of chronic diseases, in a person-centered manner. Nonetheless, there are several challenges that must be overcome to provide high-quality, usable, and effective mHealth apps. Here, we review the rationale and guidelines for the implementation of mHealth apps and the challenges regarding quality, usability, and user engagement and behavior change, with a special focus on the prevention and management of noncommunicable diseases. We suggest that a cocreation-based framework is the best method to address these challenges. Finally, we describe the current and future roles of AI in improving personalized medicine and provide recommendations for developing AI-based mHealth apps. We conclude that the implementation of AI and mHealth apps for routine clinical practice and remote health care will not be feasible until we overcome the main challenges regarding data privacy and security, quality assessment, and the reproducibility and uncertainty of AI results. Moreover, there is a lack of both standardized methods to measure the clinical outcomes of mHealth apps and techniques to encourage user engagement and behavior changes in the long term. We expect that in the near future, these obstacles will be overcome and that the ongoing European project, Watching the risk factors (WARIFA), will provide considerable advances in the implementation of AI-based mHealth apps for disease prevention and health promotion.


Subject(s)
Mobile Applications , Telemedicine , Humans , Artificial Intelligence , Reproducibility of Results , Telemedicine/methods , Risk Factors
3.
Int J Mol Sci ; 23(15)2022 Jul 28.
Article in English | MEDLINE | ID: mdl-35955457

ABSTRACT

Cell-penetrating peptides (CPP) have been shown to be efficient in the transport of cargoes into the cells, namely siRNA and DNA, proteins and peptides, and in some cases, small therapeutics. These peptides have emerged as a solution to increase drug concentrations in different tissues and various cell types, therefore having a relevant therapeutic relevance which led to clinical trials. One of them, MAP, is a model amphipathic peptide with an α-helical conformation and both hydrophilic and hydrophobic residues in opposite sides of the helix. It is composed of a mixture of alanines, leucines, and lysines (KLALKLALKALKAALKLA). The CPP MAP has the ability to translocate oligonucleotides, peptides and small proteins. However, taking advantage of its unique properties, in recent years innovative concepts were developed, such as in silico studies of modelling with receptors, coupling and repurposing drugs in the central nervous system and oncology, or involving the construction of dual-drug delivery systems using nanoparticles. In addition to designs of MAP-linked vehicles and strategies to achieve highly effective yet less toxic chemotherapy, this review will be focused on unique molecular structure and how it determines its cellular activity, and also intends to address the most recent and frankly motivating issues for the future.


Subject(s)
Cell-Penetrating Peptides , Cell-Penetrating Peptides/chemistry , Drug Delivery Systems , Hydrophobic and Hydrophilic Interactions , Oligonucleotides/metabolism , RNA, Small Interfering/genetics
4.
Int J Mol Sci ; 23(13)2022 Jun 26.
Article in English | MEDLINE | ID: mdl-35806112

ABSTRACT

Nanoparticulate systems have been widely investigated as delivery vectors for efficient drug delivery in different diseases. Nanostructured lipid carriers (NLC) are composed of both solid and liquid lipids (glyceryl dibehenate and diethylene glycol monoethyl ether) and have demonstrated enhanced biological compatibility and increased drug loading capability. Furthermore, the use of peptides, in particular cell-penetrating peptides, to functionalize nanoparticles and enhance cell membrane permeation was explored in this paper. In this paper, we described the synthesis of a new conjugated of tranylcypromine with MAP. In addition, taking into consideration our previous results, this study developed different NLCs loaded with three central nervous system (CNS) drugs (tacrine (TAC), rasagiline (RAS), and tranylcypromine (TCP)) functionalized with model amphipathic peptide (MAP) and evaluated their activity against cancer cells. Particle size analysis demonstrated NLC presented less than 200 nm and a polydispersity index less than 0.3. Moreover, in vitro results showed that conjugation of MAP with drugs led to a higher decrease in cell viability of a neuroblastoma cell line and Caco-2 cell line, more than MAP alone. Furthermore, NLC encapsulation contributed to higher cellular delivery and enhanced toxic activity at lower concentrations when compared with free or co-administration drug-MAP conjugate.


Subject(s)
Cell-Penetrating Peptides , Nanoparticles , Nanostructures , Caco-2 Cells , Cell-Penetrating Peptides/pharmacology , Central Nervous System Diseases/drug therapy , Drug Carriers/metabolism , Humans , Lipids , Particle Size , Tranylcypromine
5.
Molecules ; 27(9)2022 Apr 24.
Article in English | MEDLINE | ID: mdl-35566093

ABSTRACT

Functionalization of nanoparticles surfaces have been widely used to improve diagnostic and therapeutic biological outcome. Several methods can be applied to modify nanoparticle surface; however, in this article we focus toward a simple and less time-consuming method. We applied an adsorption method on already formulated nanostructured lipid carriers (NLC) to functionalize these nanoparticles with three distinct peptides sequences. We selected a cell-penetrating peptide (CPP), a lysine modified model amphipathic peptide (Lys(N3)-MAP), CPP/drug complex, and the neuropeptide Y. The aim of this work is to evaluate the effect of several parameters such as peptide concentration, different types of NLC, different types of peptides, and incubation medium on the physicochemical proprieties of NLC and determine if adsorption occurs. The preliminary results from zeta potential analysis indicate some evidence that this method was successful in adsorbing three types of peptides onto NLC. Several non-covalent interactions appear to be involved in peptide adsorption with the possibility of three adsorption peptide hypothesis that may occur with NLC in solution. Moreover, and for the first time, in silico docking analysis demonstrated strong interaction between CPP MAP and NPY Y1 receptor with high score values when compared to standard antagonist and NPY.


Subject(s)
Cell-Penetrating Peptides , Nanoparticles , Drug Carriers , Liposomes , Neuropeptide Y
6.
Drug Dev Ind Pharm ; 47(7): 1121-1126, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34545750

ABSTRACT

BACKGROUND: The brief-access taste aversion (BATA) model has been used as an alternative taste assessment tool to human taste panels and became an important element of pharmaceutical drug development, especially regarding pediatric patient's compliance. This model has been validated, demonstrating a concentration-dependent sensitivity to drug aversiveness, as well as the capacity to evaluate the taste-masking effects of cyclodextrins. In the BATA model, samples are presented randomly to rodents in numerous sipper tubes and a lickometer is used for the electronic record of licks in a sophisticated approach. OBJECTIVES: The aim of this study was to test possible drug taste-masking strategies. Additionally, we have used an alternative approach to measure the animal lick number in the presence of different compounds, non-simultaneously. RESULTS: In the present work we show for the first time the licking profile of different compounds during the time course of the experiment, with each animal being exposed to only one bottle of testing product. To validate the experiments, quinine hydrochloride dihydrate (QHD) was used as a bitter reference compound. CONCLUSION: The results obtained using this simple approach showed that aversiveness is dependent on the assay duration, and that it is possible to predict the aversiveness just by measuring the mass of the tested substance consumption. Moreover, some taste-masking strategies, such as those used in pediatric formulations and corresponding to the addition of sweeteners or flavors, cannot be predicted from rodents BATA model.


Subject(s)
Sweetening Agents , Taste , Animals , Child , Drug Compounding , Flavoring Agents , Humans , Quinine , Rats
7.
Int J Mol Sci ; 22(15)2021 Jul 26.
Article in English | MEDLINE | ID: mdl-34360752

ABSTRACT

Polymeric-based nano drug delivery systems have been widely exploited to overcome protein instability during formulation. Presently, a diverse range of polymeric agents can be used, among which polysaccharides, such as chitosan (CS), hyaluronic acid (HA) and cyclodextrins (CDs), are included. Due to its unique biological and physicochemical properties, CS is one of the most used polysaccharides for development of protein delivery systems. However, CS has been described as potentially immunogenic. By envisaging a biosafe cytocompatible and haemocompatible profile, this paper reports the systematic development of a delivery system based on CS and derived with HA and CDs to nanoencapsulate the model human phenylalanine hydroxylase (hPAH) through ionotropic gelation with tripolyphosphate (TPP), while maintaining protein stability and enzyme activity. By merging the combined set of biopolymers, we were able to effectively entrap hPAH within CS nanoparticles with improvements in hPAH stability and the maintenance of functional activity, while simultaneously achieving strict control of the formulation process. Detailed characterization of the developed nanoparticulate systems showed that the lead formulations were internalized by hepatocytes (HepG2 cell line), did not reveal cell toxicity and presented a safe haemocompatible profile.


Subject(s)
Chitosan , Enzymes, Immobilized , Materials Testing , Nanoparticles/chemistry , Phenylalanine Hydroxylase , Chitosan/chemistry , Chitosan/pharmacology , Drug Evaluation, Preclinical , Enzyme Stability , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/pharmacology , HEK293 Cells , Hep G2 Cells , Humans , Phenylalanine Hydroxylase/chemistry , Phenylalanine Hydroxylase/pharmacology
8.
Int J Mol Sci ; 22(1)2020 Dec 29.
Article in English | MEDLINE | ID: mdl-33383645

ABSTRACT

Drug repurposing and drug combination are two strategies that have been widely used to overcome the traditional development of new anticancer drugs. Several FDA-approved drugs for other indications have been tested and have demonstrated beneficial anticancer effects. In this connection, our research group recently reported that Tacrine, used to treat Alzheimer's Disease, inhibits the growth of breast cancer MCF-7 cells both alone and in combination with a reference drug. In this view, we have now coupled Tacrine with the model amphipathic cell-penetrating peptide (CPP) MAP, to ascertain whether coupling of the CPP might enhance the drug's antiproliferative properties. To this end, we synthesized MAP through solid-phase peptide synthesis, coupled it with Tacrine, and made a comparative evaluation of the parent drug, peptide, and the conjugate regarding their permeability across the blood-brain barrier (BBB), ability to inhibit acetylcholinesterase (AChE) in vitro, and antiproliferative activity on cancer cells. Both MAP and its Tacrine conjugate were highly toxic to MCF-7 and SH-SY5Y cells. In turn, BBB-permeability studies were inconclusive, and conjugation to the CPP led to a considerable loss of Tacrine function as an AChE inhibitor. Nonetheless, this work reinforces the potential of repurposing Tacrine for cancer and enhances the antiproliferative activity of this drug through its conjugation to a CPP.


Subject(s)
Antineoplastic Agents/pharmacology , Peptides/chemistry , Peptides/pharmacology , Surface-Active Agents/chemistry , Surface-Active Agents/pharmacology , Tacrine/chemistry , Blood-Brain Barrier/metabolism , Cell Line, Tumor , Cell-Penetrating Peptides/chemistry , Cell-Penetrating Peptides/pharmacology , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/pharmacology , Dose-Response Relationship, Drug , Drug Synergism , Humans , Permeability
9.
AAPS PharmSciTech ; 19(4): 1625-1636, 2018 May.
Article in English | MEDLINE | ID: mdl-29488195

ABSTRACT

Eradication of Gram-positive biofilms is a critical aspect in implant-associated infection treatment. Although antibiotic-containing particulate carriers may be a promising strategy for overcoming biofilm tolerance, the assessment of their interaction with biofilms has not been fully explored. In the present work, the antibiofilm activity of daptomycin- and vancomycin-loaded poly(methyl methacrylate) (PMMA) and PMMA-Eudragit RL 100 (EUD) microparticles against methicillin-resistant Staphylococcus aureus (MRSA) and polysaccharide intercellular adhesin-positive S. epidermidis biofilms was investigated using isothermal microcalorimetry (IMC) and fluorescence in situ hybridization (FISH). The minimal biofilm inhibitory concentrations (MBIC) of MRSA biofilms, as determined by IMC, were 5 and 20 mg/mL for daptomycin- and vancomycin-loaded PMMA microparticles, respectively. S. epidermidis biofilms were less susceptible, with a MBIC of 20 mg/mL for daptomycin-loaded PMMA microparticles. Vancomycin-loaded microparticles were ineffective. Adding EUD to the formulation caused a 4- and 16-fold reduction of the MBIC values of daptomycin-loaded microparticles for S. aureus and S. epidermidis, respectively. FISH corroborated the IMC results and provided additional insights on the antibiofilm effect of these particles. According to microscopic analysis, only daptomycin-loaded PMMA-EUD microparticles were causing a pronounced reduction in biofilm mass for both strains. Taken together, although IMC indicated that a biofilm inhibition was achieved, microscopy showed that the biofilm was not eradicated and still contained FISH-positive, presumably viable bacteria, thus indicating that combining the two techniques is essential to fully assess the effect of microparticles on staphylococcal biofilms.


Subject(s)
Biofilms/drug effects , Daptomycin/chemistry , Methicillin-Resistant Staphylococcus aureus/drug effects , Microspheres , Staphylococcus epidermidis/drug effects , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/metabolism , Biofilms/growth & development , Daptomycin/administration & dosage , Daptomycin/metabolism , In Situ Hybridization, Fluorescence , Methicillin-Resistant Staphylococcus aureus/physiology , Microbial Sensitivity Tests/methods , Staphylococcus epidermidis/physiology
10.
Mol Pharm ; 14(9): 2977-2990, 2017 09 05.
Article in English | MEDLINE | ID: mdl-28809501

ABSTRACT

Solid lipid nanoparticles (SLN) containing rifabutin (RFB), with pulmonary administration purposes, were developed through a technique that avoids the use of organic solvents or sonication. To facilitate their pulmonary delivery, the RFB-loaded SLN were included in microspheres of appropriate size using suitable excipients (mannitol and trehalose) through a spray-drying technique. Confocal analysis microscopy showed that microspheres are spherical and that SLN are efficiently microencapsulated and homogeneously distributed throughout the microsphere matrices. The aerodynamic diameters observed an optimal distribution for reaching the alveolar region. The dry powder's performance during aerosolization and the in vitro drug deposition were tested using a twin-impinger approach, which confirmed that the microspheres can reach the deep lung. Isothermal titration calorimetry revealed that SLN have higher affinity for mannitol than for trehalose. Upon microsphere dissolution in aqueous media, SLN were readily recovered, maintaining their physicochemical properties. When these dry powders reach the deep lung, microspheres are expected to readily dissolve, delivering the SLN which, in turn, will release RFB. The in vivo biodistribution of microencapsulated RFB-SLN demonstrated that the antibiotic achieved the tested organs 15 and 30 min post pulmonary administration. Their antimycobacterial activity was also evaluated in a murine model of infection with a Mycobacterium tuberculosis strain H37Rv resulting in an enhancement of activity against M. tuberculosis infection compared to nontreated animals. These results suggest that RFB-SLN microencapsulation is a promising approach for the treatment of tuberculosis.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/metabolism , Lipids/chemistry , Lung/metabolism , Nanoparticles/chemistry , Animals , Anti-Bacterial Agents/therapeutic use , Drug Compounding , Mice , Mice, Inbred BALB C , Microscopy, Confocal , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/pathogenicity , Nanoparticles/administration & dosage , Rifabutin/administration & dosage , Rifabutin/metabolism , Rifabutin/therapeutic use
11.
Mar Drugs ; 15(12)2017 Dec 01.
Article in English | MEDLINE | ID: mdl-29194378

ABSTRACT

Pharmaceutical approaches based on nanotechnologies and the development of eye drops composed of the mucoadhesive polymers chitosan and hyaluronic acid are emerging strategies for the efficient treatment of ocular diseases. These innovative nanoparticulate systems aim to increase drugs' bioavailability at the ocular surface. For the successful development of these systems, the evaluation of mucoahesiveness (the interaction between the ocular delivery system and mucins present on the eye) is of utmost importance. In this context, the aim of the present work was to investigate the mucoadhesivity of a novel nanoparticle eye drop formulation containing an antibiotic (ceftazidime) intended to treat eye infections. Eye drop formulations comprised a polymer (hydroxypropyl) methyl cellulose (HPMC) 0.75% (w/v) in an isotonic solution incorporating chitosan/sodium tripolyphosphate (TPP)-hyaluronic acid-based nanoparticles containing ceftazidime. The viscosity of the nanoparticles, and the gels incorporating the nanoparticles were characterized in contact with mucin at different mass ratios, allowing the calculation of the rheological synergism parameter (∆η). Results showed that at different nanoparticle eye formulation:mucin weight ratios, a minimum in viscosity occurred which resulted in a negative rheological synergism. Additionally, the results highlighted the mucoadhesivity of the novel ocular formulation and its ability to interact with the ocular surface, thus increasing the drug residence time in the eye. Moreover, the in vitro release and permeation studies showed a prolonged drug release profile from the chitosan/TPP-hyaluronic acid nanoparticles gel formulation. Furthermore, the gel formulations were not cytotoxic on ARPE-19 and HEK293T cell lines, evaluated by the metabolic and membrane integrity tests. The formulation was stable and the drug active, as shown by microbiological studies. In conclusion, chitosan/TPP-hyaluronic acid nanoparticle eye drop formulations are a promising platform for ocular drug delivery with enhanced mucoadhesive properties.


Subject(s)
Chitosan/chemistry , Ophthalmic Solutions/chemistry , Administration, Ophthalmic , Animals , Anti-Bacterial Agents/administration & dosage , Aquatic Organisms , Ceftazidime/administration & dosage , Drug Delivery Systems , HEK293 Cells/drug effects , Humans , Nanoparticles , Ophthalmic Solutions/administration & dosage , Ophthalmic Solutions/pharmacology
12.
J Microencapsul ; 34(2): 203-217, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28378596

ABSTRACT

The aim of this study was to develop a novel BCG-loaded chitosan vaccine with high association efficiency which can afford efficient interaction with APC and elicit local and Th1-type-specific immune response after intranasal administration. Chitosan-suspended BCG and BCG-loaded chitosan-alginate microparticles were prepared by ionotropic gelation. Interaction with APC was evaluated by fluorescence microscopy using rBCG-GFP. Specific immune responses were evaluated following intranasal immunisation of mice. Cellular uptake was approximately two-fold higher for chitosan-suspended BCG. A single dose of BCG-loaded microparticles or chitosan-suspended BCG by intranasal route improved Th1-type response compared with subcutaneous BCG. Chitosan-suspended BCG originated the highest mucosal response in the lungs by intranasal route. These positive results indicate that the proposed approach of whole live BCG microencapsulation in chitosan-alginate for intranasal immunisation was successful in allowing efficient interaction with APC, while improving the cellular immune response, which is of interest for local immunisation against tuberculosis.


Subject(s)
BCG Vaccine/chemistry , Chitosan/chemistry , Macrophages/drug effects , Administration, Intranasal , Animals , Antibodies, Bacterial/blood , BCG Vaccine/administration & dosage , Female , Humans , Immunoglobulin A/analysis , Immunoglobulin G/blood , Mice , Mice, Inbred BALB C , Mycobacterium bovis , THP-1 Cells
13.
Pharm Dev Technol ; 22(2): 266-274, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27499389

ABSTRACT

Oral mucositis (OM) is a common adverse reaction to radiotherapy and chemotherapy in oncology. Its treatment requires oral formulations that enhance therapy compliance, improve administration and ensure drug effectiveness. Solid dosage forms that act by slow dissolution, such as pastilles, are an effective alternative to mouthwashes, for their versatility, ease of administration and extended residence time in the oral cavity. The present work describes the development and stability studies of an innovative formulation of nystatin and lidocaine pastilles for the treatment of oral mucositis. Full pharmaceutical quality testing was carried out, including disintegration and dissolution testing, texture profile analysis, grittiness and an antifungal activity testing. A soft pastille formulation containing 0.25% lidocaine and 78,000 IU nystatin was obtained, presenting suitable pharmaceutical characteristics, as a disintegration time of 17 ± 2 min, dissolution rate and microbiological and physicochemical for 30 days when stored at 2-8 °C under light protection. Palatability was also evaluated, being well accepted by a panel of 38 healthy volunteers. This formulation allows an accurate drug dosing by the prescriber, while enabling the patients to control the retention time of the drugs in the oral cavity and consequently manage their pain treatment.


Subject(s)
Antifungal Agents/administration & dosage , Candida albicans/drug effects , Candidiasis, Oral/drug therapy , Lidocaine/administration & dosage , Nystatin/administration & dosage , Stomatitis/drug therapy , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Drug Liberation , Hardness , Humans , Lidocaine/chemistry , Lidocaine/pharmacology , Nystatin/chemistry , Nystatin/pharmacology , Tablets
14.
Nanomedicine ; 12(1): 143-61, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26410277

ABSTRACT

During the past decade, the number of studies describing nanostructured lipid carriers (NLCs)-based formulations has been dramatically increased. The raise in NLC exploitation is essentially due to defeated barriers within the technological process of lipid-based nanoparticles' formulation and increased knowledge of the underlying mechanisms of transport of NLCs via different routes of administration. This review article aims to give an overview on the current state of the art of NLC as controlled drug delivery systems for future clinics through novel NLC applications providing examples of successfull outcomes. The reported data clearly illustrate the promise of these nanoparticles for novel treatments in the near future. From the Clinical Editor: The understanding of the nanostructured lipid carriers (NLC)-based formulations has improved with continuing research recently. The result has seen an increase in the use of these in the clinical setting. In this comprehensive review, the authors discussed the current state and major challenges in the use of nanostructured lipid carriers as controlled drug delivery systems.


Subject(s)
Forecasting , Lipids/chemistry , Liposomes/chemistry , Nanocapsules/chemistry , Nanocapsules/ultrastructure , Nanomedicine/trends , Diffusion
15.
Mar Drugs ; 14(5)2016 May 11.
Article in English | MEDLINE | ID: mdl-27187418

ABSTRACT

The aim of the present study was to develop novel Mycobacterium bovis bacille Calmette-Guérin (BCG)-loaded polymeric microparticles with optimized particle surface characteristics and biocompatibility, so that whole live attenuated bacteria could be further used for pre-exposure vaccination against Mycobacterium tuberculosis by the intranasal route. BCG was encapsulated in chitosan and alginate microparticles through three different polyionic complexation methods by high speed stirring. For comparison purposes, similar formulations were prepared with high shear homogenization and sonication. Additional optimization studies were conducted with polymers of different quality specifications in a wide range of pH values, and with three different cryoprotectors. Particle morphology, size distribution, encapsulation efficiency, surface charge, physicochemical properties and biocompatibility were assessed. Particles exhibited a micrometer size and a spherical morphology. Chitosan addition to BCG shifted the bacilli surface charge from negative zeta potential values to strongly positive ones. Chitosan of low molecular weight produced particle suspensions of lower size distribution and higher stability, allowing efficient BCG encapsulation and biocompatibility. Particle formulation consistency was improved when the availability of functional groups from alginate and chitosan was close to stoichiometric proportion. Thus, the herein described microparticulate system constitutes a promising strategy to deliver BCG vaccine by the intranasal route.


Subject(s)
Alginates/chemistry , BCG Vaccine/chemistry , Chitosan/chemistry , Mycobacterium bovis/chemistry , Nanoparticles/chemistry , Administration, Intranasal , Animals , BCG Vaccine/immunology , Biocompatible Materials/chemistry , Cells, Cultured , Chemistry, Pharmaceutical/methods , Drug Carriers/chemistry , Glucuronic Acid/chemistry , Hexuronic Acids/chemistry , Mycobacterium tuberculosis/immunology , Particle Size , Polymers/chemistry
16.
Pharm Res ; 31(11): 3136-49, 2014 Nov.
Article in English | MEDLINE | ID: mdl-24842662

ABSTRACT

PURPOSE: To prepare and thoroughly characterize a new polymorph of the broad-spectrum antibiotic minocycline from its hydrochloride dehydrate salts. METHODS: The new minocycline hydrochloride polymorph was prepared by means of the antisolvent effect caused by carbon dioxide. Minocycline recrystallized as a red crystalline hydrochloride salt, starting from solutions or suspensions containing CO2 and ethanol under defined conditions of temperature, pressure and composition. RESULTS: This novel polymorph (ß-minocycline) revealed characteristic PXRD and FTIR patterns and a high melting point (of 247 ºC) compared to the initial minocycline hydrochloride hydrates (α-minocycline). Upon dissolution the new polymorph showed full anti-microbial activity. Solid-state NMR and DSC studies evidenced the higher chemical stability and crystalline homogeneity of ß-minocycline compared to the commercial chlorohydrate powders. Molecular structures of both minocyclines present relevant differences as shown by multinuclear solid-state NMR. CONCLUSIONS: This work describes a new crystalline structure of minocycline and evidences the ability of ethanol-CO2 system in removing water molecules from the crystalline structure of this API, at modest pressure, temperature and relatively short time (2 h), while controlling the crystal habit. This process has therefore the potential to become a consistent alternative towards the control of the solid form of APIs.


Subject(s)
Carbon Dioxide/chemistry , Minocycline/chemistry , Polymers/chemistry , Anti-Infective Agents/chemistry , Crystallization/methods , Ethanol/chemistry , Powders/chemistry , Solubility , Solutions/chemistry , Suspensions/chemistry , Temperature , Water/chemistry
17.
Eur J Pharm Sci ; 202: 106896, 2024 Nov 01.
Article in English | MEDLINE | ID: mdl-39250981

ABSTRACT

Recent advances in understanding Alzheimer's disease (AD) suggest the possibility of an infectious etiology, with Porphyromonas gingivalis emerging as a prime suspect in contributing to AD. P. gingivalis may invade systemic circulation via weakened oral/intestinal barriers and then cross the blood-brain barrier (BBB), reaching the brain and precipitating AD pathology. Based on the proposed links between P. gingivalis and AD, a prospective approach is the development of an oral nanovaccine containing P. gingivalis antigens for mucosal delivery. Targeting the gut-associated lymphoid tissue (GALT), the nanovaccine may elicit both mucosal and systemic immunity, thereby hampering P. gingivalis ability to breach the oral/intestinal barriers and the BBB, respectively. The present study describes the optimization, characterization, and in vitro evaluation of a candidate chitosan-coated poly(lactic-co-glycolic acid) (PLGA-CS) nanovaccine containing a P. gingivalis antigen extract. The nanocarrier was prepared using the double emulsion solvent evaporation method and optimized for selected experimental factors, e.g. PLGA amount, surfactant concentration, w1/o phase ratio, applying a d-optimal statistical design to target the desired physicochemical criteria for its intended application. After nanocarrier optimization, the nanovaccine was characterized in terms of particle size, polydispersity index (PdI), ζ-potential, encapsulation efficiency (EE), drug loading (DL), morphology, and in vitro release profile, as well as for mucoadhesivity, stability under simulated gastrointestinal conditions, antigen integrity, in vitro cytotoxicity and uptake using THP-1 macrophages. The candidate PLGA-CS nanovaccine demonstrated appropriate physicochemical, mucoadhesive, and antigen release properties for oral delivery, along with acceptable levels of EE (55.3 ± 3.5 %) and DL (1.84 ± 0.12 %). The integrity of the encapsulated antigens remained uncompromised throughout NPs production and simulated gastrointestinal exposure, as confirmed by SDS-PAGE and Western blotting analyses. Furthermore, the nanovaccine showed effective in vitro uptake, while exhibiting low cytotoxicity. Taken together, these findings underscore the potential of PLGA-CS NPs as carriers for adequate antigen mucosal delivery, paving the way for further investigations into their applicability as vaccine candidates against P. gingivalis.


Subject(s)
Antigens, Bacterial , Chitosan , Drug Carriers , Nanoparticles , Polylactic Acid-Polyglycolic Acid Copolymer , Porphyromonas gingivalis , Chitosan/chemistry , Chitosan/administration & dosage , Porphyromonas gingivalis/drug effects , Humans , Polylactic Acid-Polyglycolic Acid Copolymer/chemistry , Drug Carriers/chemistry , Nanoparticles/administration & dosage , Antigens, Bacterial/administration & dosage , Antigens, Bacterial/immunology , Bacterial Vaccines/administration & dosage , Bacterial Vaccines/immunology , Drug Liberation
18.
Exp Parasitol ; 135(1): 166-74, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23830988

ABSTRACT

Malaria cysteine proteases have been shown to be immunogenic and are being exploited as serodiagnostic markers, drug and vaccine targets. Several Plasmodium spp. cysteine proteases have been described and the best characterized of these are the falcipains, a family of papain-family enzymes. Falcipain-2 and falcipain-3 act in concert with other proteases to hydrolyze host erythrocyte hemoglobin in the parasite food vacuole. Falcipain-1 has less similarity to the other falcipains and its physiological role in parasite asexual blood stage still remains uncertain. Immunolocalization studies using an antibody developed against the Plasmodium chabaudi recombinant chabaupain-1, the falcipain-1 ortholog, were performed confirming its cellular localization in both erythrocyte and mosquito ookinete stage. Immunostaining of chabaupain-1 preferentially in apical portion of parasite ookinete suggests that this protease may be related with parasite egression from mosquito midgut. Immune responses to chabaupain-1 were evaluated using two different adjuvants, chitosan nanoparticles and hydroxide aluminum. Mice immunized with the recombinant protein alone or in association with nanoparticles were challenged with P. chabaudi showing that immunization with the recombinant protein confers partial protection to blood stage infection in BALB/c animal model.


Subject(s)
Antibodies, Protozoan/biosynthesis , Cysteine Proteases/immunology , Malaria Vaccines , Malaria/prevention & control , Plasmodium chabaudi/enzymology , Plasmodium chabaudi/immunology , Animals , Anopheles/parasitology , Antibodies, Monoclonal/biosynthesis , Antibodies, Monoclonal/immunology , Antibodies, Protozoan/immunology , Cysteine Proteases/analysis , Cysteine Proteases/genetics , Cytokines/metabolism , Disease Models, Animal , Erythrocytes/parasitology , Female , Mice , Mice, Inbred BALB C , Microscopy, Fluorescence , Plasmodium berghei/physiology , Plasmodium chabaudi/growth & development , Recombinant Proteins/analysis , Recombinant Proteins/genetics , Recombinant Proteins/immunology , Vaccines, Synthetic
19.
Drug Deliv Transl Res ; 13(12): 3030-3058, 2023 12.
Article in English | MEDLINE | ID: mdl-37294425

ABSTRACT

Microencapsulation of the therapeutical monoclonal antibody infliximab (INF) was investigated as an innovative approach to improve its stability and to achieve formulations with convenient features for intra-articular administration. Ultrasonic atomization (UA), a novel alternative to microencapsulate labile drugs, was compared with the conventional emulsion/evaporation method (Em/Ev) using biodegradable polymers, specifically Polyactive® 1000PEOT70PBT30 [poly(ethylene-oxide-terephthalate)/poly(butylene-terephthalate); PEOT-PBT] and its polymeric blends with poly-(D, L-lactide-co-glycolide) (PLGA) RG502 and RG503 (PEOT-PBT:PLGA; 65:35). Six different formulations of spherical core-shell microcapsules were successfully developed and characterized. The UA method achieved a significantly higher encapsulation efficiency (69.7-80.25%) than Em/Ev (17.3-23.0%). Mean particle size, strongly determined by the microencapsulation method and to a lesser extent by polymeric composition, ranged from 26.6 to 49.9 µm for UA and 1.5-2.1 µm for Em/Ev. All formulations demonstrated sustained INF release in vitro for up to 24 days, with release rates modulated by polymeric composition and microencapsulation technique. Both methods preserved INF biological activity, with microencapsulated INF showing higher efficacy than commercial formulations at comparable doses regarding bioactive tumor necrosis factor-alpha (TNF-α) neutralization according to WEHI-13VAR bioassay. Microparticles' biocompatibility and extensive internalization by THP-1-derived macrophages was demonstrated. Furthermore, high in vitro anti-inflammatory activity was achieved after treatment of THP-1 cells with INF-loaded microcapsules, significatively reducing in vitro production of TNF-α and interleucine-6 (Il-6).


Subject(s)
Arthritis, Rheumatoid , Biological Products , Humans , Infliximab , Tumor Necrosis Factor-alpha , Capsules , Polymers , Arthritis, Rheumatoid/drug therapy , Particle Size , Microspheres
20.
Life Sci ; 329: 121838, 2023 Sep 15.
Article in English | MEDLINE | ID: mdl-37290668

ABSTRACT

There has been an increased interest of the scientific community in cannabis and its constituents for therapeutic purposes. Although it is believed that cannabinoids can be effective for a few different conditions and syndromes, there are little objective data that clearly support the use of cannabis, cannabis extracts or even cannabidiol (CBD) oil. This review aims to explore the therapeutic potential of phytocannabinoids and synthetic cannabinoids for the treatment of several diseases. A broad search covering the past five years, was performed in PubMed and ClinicalTrial.gov databases, to identify papers focusing on the use of medical phytocannabinoids in terms of tolerability, efficacy and safety. Accordingly, there are preclinical data supporting the use of phytocannabinoids and synthetic cannabinoids for the management of neurological pathologies, acute and chronical pain, cancer, psychiatric disorders and chemotherapy-induced emetic symptoms. However, regarding the clinical trials, most of the collected data do not fully support the use of cannabinoids in the treatment of such conditions. Consequently, more studies are still needed to clarify ascertain if the use of these compounds is useful in the management of different pathologies.


Subject(s)
Cannabidiol , Cannabinoids , Cannabis , Neoplasms , Humans , Cannabinoids/pharmacology , Cannabinoids/therapeutic use , Cannabinoid Receptor Agonists , Neoplasms/drug therapy , Cannabidiol/pharmacology , Cannabidiol/therapeutic use
SELECTION OF CITATIONS
SEARCH DETAIL