Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 9 de 9
Filter
Add more filters










Publication year range
1.
Biomaterials ; 308: 122567, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38603825

ABSTRACT

Frequent injections of anti-CD124 monoclonal antibody (αCD124) over long periods of time are used to treat chronic rhinosinusitis with nasal polyps (CRSwNP). Needle-free, intranasal administration (i.n.) of αCD124 is expected to provide advantages of localized delivery, improved efficacy, and enhanced medication adherence. However, delivery barriers such as the mucus and epithelium in the nasal tissue impede penetration of αCD124. Herein, two novel protamine nanoconstructs: allyl glycidyl ether conjugated protamine (Nano-P) and polyamidoamine-linked protamine (Dendri-P) were synthesized and showed enhanced αCD124 penetration through multiple epithelial layers compared to protamine in mice. αCD124 was mixed with Nano-P or Dendri-P and then intranasally delivered for the treatment of severe CRSwNP in mice. Micro-CT and pathological changes in nasal turbinates showed that these two nano-formulations achieved ∼50 % and ∼40 % reductions in nasal polypoid lesions and eosinophil count, respectively. Both nano-formulations provided enhanced efficacy in suppressing nasal and systemic Immunoglobulin E (IgE) and nasal type 2 inflammatory biomarkers, such as interleukin 13 (IL-13) and IL-25. These effects were superior to those in the protamine formulation group and subcutaneous (s.c.) αCD124 given at a 12.5-fold higher dose. Intranasal delivery of protamine, Nano-P, or Dendri-P did not induce any measurable toxicities in mice.


Subject(s)
Antibodies, Monoclonal , Nasal Polyps , Protamines , Rhinosinusitis , Animals , Female , Mice , Administration, Intranasal , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal/pharmacology , Chronic Disease , Mice, Inbred BALB C , Nasal Polyps/drug therapy , Nasal Polyps/pathology , Protamines/chemistry , Rhinosinusitis/drug therapy
2.
J Control Release ; 343: 347-360, 2022 03.
Article in English | MEDLINE | ID: mdl-35085699

ABSTRACT

Human insulin (HI) has fascinating metal-facilitated self-assembly properties that are essential for its biological function. HI has a natural Zn2+ binding site and we have previously shown that covalently attached abiotic ligands (e.g., bipyridine, terpyridine) can lead to the formation of nanosized oligomeric structures through the coordination of metal ions. Here we studied the hypothesis that metal ions can be used to directly control the pharmacokinetics of insulin after covalent attachment of an abiotic ligand that binds metal ions. We evaluated the pharmacokinetics (PK) and biodistribution of HI self-assemblies directed by metal ion coordination (i.e., Fe2+/Zn2+, Eu3+/Zn2+, Fe2+/Co3+) using preclinical SPECT/CT imaging and ex vivo gamma counting. HI was site-specifically modified with terpyridine (Tpy) at the PheB1 or LysB29 position to create conjugates that bind either Fe2+ or Eu3+, while its natural binding site (HisB10) preferentially coordinates with either Zn2+ or Co3+. HI was also functionalized with trans-cyclooctene (TCO) opposite to Tpy at PheB1 or LysB29, respectively, to allow for tetrazine-TCO coupling via a tetrazine-modified DTPA followed by 111In-radiolabeling for SPECT/CT imaging. When the 111In-B29Tpy-HI conjugate was coordinated with Fe2+/Zn2+, its retention at the injection site 6 h after injection was ~8-fold higher than the control without the metal ions, while its kidney accumulation was lower. 111In-B1Tpy-HI showed comparable retention at the injection site 6 h after injection and slightly increased retention at 24 h. However, higher kidney accumulation and residence time of degraded 111In-B1Tpy-HI was observed compared to that of 111In-B29Tpy-HI. Quantitative PK analysis based on SPECT/CT images confirmed slower distribution from the injection site of the HI-metal ion assemblies compared to control HI conjugates. Our results show that the Tpy-binding site (i.e., PheB1 or LysB29) on HI and its coordination with the added metal ions (i.e., Fe2+/Zn2+ or Fe2+/Co3+) directed the distribution half-life of HI significantly. This clearly indicates that the PK of insulin can be controlled by complexation with different metal ions.


Subject(s)
Insulin , Tomography, Emission-Computed, Single-Photon , Humans , Insulin/chemistry , Ions/chemistry , Kinetics , Ligands , Tissue Distribution , Tomography, X-Ray Computed
3.
ACS Biomater Sci Eng ; 7(6): 2823-2834, 2021 06 14.
Article in English | MEDLINE | ID: mdl-33826291

ABSTRACT

Albumin is widely used in pharmaceutical applications to alter the pharmacokinetic profile, improve efficacy, or decrease the toxicity of active compounds. Various drug delivery systems using albumin have been reported, including microparticles. Macroaggregated albumin (MAA) is one of the more common forms of albumin microparticles, which is predominately used for lung perfusion imaging when labeled with radionuclide technetium-99m (99mTc). These microparticles are formed by heat-denaturing albumin in a bulk solution, making it very challenging to control the size and dispersity of the preparations (coefficient of variation, CV, ∼50%). In this work, we developed an integrated microfluidics platform to create more tunable and precise MAA particles, the so-called microfluidic-MAA (M2A2). The microfluidic chips, prepared using off-stoichiometry thiol-ene chemistry, consist of a flow-focusing region followed by an extended and water-heated curing channel (85 °C). M2A2 particles with diameters between 70 and 300 µm with CVs between 10 and 20% were reliably prepared by adjusting the flow rates of the dispersed and continuous phases. To demonstrate the pharmaceutical utility of M2A2, particles were labeled with indium-111 (111In) and their distribution was assessed in healthy mice using nuclear imaging. 111In-M2A2 behaved similarly to 99mTc-MAA, with lung uptake predominately observed early on followed by clearance over time by the reticuloendothelial and renal systems. Our microfluidic chip represents an elegant and controllable method to prepare albumin microparticles for biomedical applications.


Subject(s)
Microfluidics , Technetium Tc 99m Aggregated Albumin , Albumins , Animals , Hot Temperature , Mice , Radiopharmaceuticals
4.
ACS Appl Mater Interfaces ; 13(9): 10705-10718, 2021 Mar 10.
Article in English | MEDLINE | ID: mdl-33635046

ABSTRACT

The validation of metal-phenolic nanoparticles (MPNs) in preclinical imaging studies represents a growing field of interest due to their versatility in forming predesigned structures with unique properties. Before MPNs can be used in medicine, their pharmacokinetics must be optimized so that accumulation in nontargeted organs is prevented and toxicity is minimized. Here, we report the fabrication of MPNs made of a coordination polymer core that combines In(III), Cu(II), and a mixture of the imidazole 1,4-bis(imidazole-1-ylmethyl)-benzene and the catechol 3,4-dihydroxycinnamic acid ligands. Furthermore, a phenolic-based coating was used as an anchoring platform to attach poly(ethylene glycol) (PEG). The resulting MPNs, with effective hydrodynamic diameters of around 120 nm, could be further derivatized with surface-embedded molecules, such as folic acid, to facilitate in vivo targeting and multifunctionality. The prepared MPNs were evaluated for in vitro plasma stability, cytotoxicity, and cell internalization and found to be biocompatible under physiological conditions. First, biomedical evaluations were then performed by intrinsically incorporating trace amounts of the radioactive metals 111In or 64Cu during the MPN synthesis directly into their polymeric matrix. The resulting particles, which had identical physicochemical properties to their nonradioactive counterparts, were used to perform in vivo single-photon emission computed tomography (SPECT) and positron emission tomography (PET) in tumor-bearing mice. The ability to incorporate multiple metals and radiometals into MPNs illustrates the diverse range of functional nanoparticles that can be prepared with this approach and broadens the scope of these nanoconstructs as multimodal preclinical imaging agents.


Subject(s)
Caffeic Acids/chemistry , Metal Nanoparticles/chemistry , Neoplasms/diagnostic imaging , Radiopharmaceuticals/chemistry , Animals , Caffeic Acids/pharmacokinetics , Caffeic Acids/toxicity , Cell Line, Tumor , Copper Radioisotopes/chemistry , Copper Radioisotopes/pharmacokinetics , Copper Radioisotopes/toxicity , Female , Humans , Imidazoles/chemistry , Imidazoles/pharmacokinetics , Imidazoles/toxicity , Indium Radioisotopes/chemistry , Indium Radioisotopes/pharmacokinetics , Indium Radioisotopes/toxicity , Ligands , Metal Nanoparticles/toxicity , Mice, Inbred BALB C , Multimodal Imaging , Positron-Emission Tomography , Proof of Concept Study , Radiopharmaceuticals/pharmacokinetics , Radiopharmaceuticals/toxicity , Tomography, Emission-Computed, Single-Photon , Tomography, X-Ray Computed
5.
Arthritis Res Ther ; 22(1): 281, 2020 11 30.
Article in English | MEDLINE | ID: mdl-33256854

ABSTRACT

BACKGROUND: The discovery and development of new medicines requires high-throughput screening of possible therapeutics in a specific model of the disease. Infrared thermal imaging (IRT) is a modern assessment method with extensive clinical and preclinical applications. Employing IRT in longitudinal preclinical setting to monitor arthritis onset, disease activity and therapeutic efficacies requires a standardized framework to provide reproducible quantitative data as a precondition for clinical studies. METHODS: Here, we established the accuracy and reliability of an inexpensive smartphone connected infrared (IR) camera against known temperature objects as well as certified blackbody calibration equipment. An easy to use protocol incorporating contactless image acquisition and computer-assisted data analysis was developed to detect disease-related temperature changes in a collagen-induced arthritis (CIA) mouse model and validated by comparison with two conventional methods, clinical arthritis scoring and paw thickness measurement. We implemented IRT to demonstrate the beneficial therapeutic effect of nanoparticle drug delivery versus free methotrexate (MTX) in vivo. RESULTS: The calibrations revealed high accuracy and reliability of the IR camera for detecting temperature changes in the rheumatoid arthritis animal model. Significant positive correlation was found between temperature changes and paw thickness measurements as the disease progressed. IRT was found to be superior over the conventional techniques specially at early arthritis onset, when it is difficult to observe subclinical signs and measure structural changes. CONCLUSION: IRT proved to be a valid and unbiased method to detect temperature changes and quantify the degree of inflammation in a rapid and reproducible manner in longitudinal preclinical drug efficacy studies.


Subject(s)
Arthritis, Experimental , Arthritis, Rheumatoid , Animals , Arthritis, Experimental/diagnostic imaging , Arthritis, Experimental/drug therapy , Arthritis, Rheumatoid/diagnostic imaging , Arthritis, Rheumatoid/drug therapy , Disease Models, Animal , Methotrexate , Mice , Reproducibility of Results
6.
Chembiochem ; 21(23): 3338-3348, 2020 12 01.
Article in English | MEDLINE | ID: mdl-32667131

ABSTRACT

The controlled self-assembly of peptide- and protein-based pharmaceuticals is of central importance for their mode of action and tuning of their properties. Peptide YY3-36 (PYY3-36 ) is a 36-residue peptide hormone that reduces food intake when peripherally administered. Herein, we describe the synthesis of a PYY3-36 analogue functionalized with a metal-ion-binding 2,2'-bipyridine ligand that enables self-assembly through metal complexation. Upon addition of CuII , the bipyridine-modified PYY3-36 peptide binds stoichiometric quantities of metal ions in solution and contributes to the organization of higher-order assemblies. In this study, we aimed to explore the size effect of the self-assembly in vivo by using non-invasive quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) imaging. For this purpose, bipyridine-modified PYY3-36 was radiolabeled with a chelator holding 111 InIII , followed by the addition of CuII to the bipyridine ligand. SPECT/CT imaging and biodistribution studies showed fast renal clearance and accumulation in the kidney cortex. The radiolabeled bipyridyl-PYY3-36 conjugates with and without CuII presented a slightly slower excretion 1 h post injection compared to the unmodified-PYY3-36 , thus demonstrating that higher self-assemblies of the peptide might have an effect on the pharmacokinetics.


Subject(s)
Copper/pharmacokinetics , Peptide YY/pharmacokinetics , Tomography, Emission-Computed, Single-Photon , Tomography, X-Ray Computed , 2,2'-Dipyridyl/chemistry , 2,2'-Dipyridyl/pharmacokinetics , Animals , Coordination Complexes/chemical synthesis , Coordination Complexes/chemistry , Coordination Complexes/pharmacokinetics , Copper/chemistry , Female , Kidney Cortex/chemistry , Kidney Cortex/metabolism , Ligands , Mice , Mice, Inbred C57BL , Peptide YY/chemical synthesis , Peptide YY/chemistry , Renal Elimination , Tissue Distribution
7.
Endocr Connect ; 9(4): 337-345, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32213660

ABSTRACT

INTRODUCTION AND AIM: Ectopic ACTH secretion (EAS) is mostly secondary to thoracic/abdominal neuroendocrine tumours (NETs) or small cell-lung carcinoma (SCLC). We studied the diagnostic accuracy of CT with 68Ga-Dota derivatives (68Ga-SSTR) PET in localizing ACTH-secreting tumor in patients with EAS. MATERIALS AND METHODS: 68Ga-SSTR-PET/CT was performed and compared with the nearest enhanced CT in 18 cases (16 primary and 2 recurrent neoplasms). Unspecific, indeterminate and false-positive uptakes were assessed using conventional imaging, follow-up or histology. RESULTS: We diagnosed 13 thoracic (9 primary and 2 recurrent bronchial carcinoids, 2 SCLCs) and 1 abdominal (pancreatic NET) tumors. Eight ACTH-secreting tumors were promptly identified at EAS diagnosis ('overt', four pulmonary carcinoids with two recurrences and two SCLC); six EAS have been discovered during the subsequent follow-up ('covert', five bronchial carcinoids and one pancreatic NET). At the time of EAS diagnosis, imaging was able to correctly detect the ACTH-secreting tumour in 8/18 cases (6 new diagnosis and 2 recurrences). During the follow-up, six out of initially ten 'occult' cases became 'covert'. At last available follow-up, CT and 68Ga-SSTR-PET/CT were able to diagnose 11/18 and 12/18 ACTH-secreting tumours, respectively (11/14 and 12/14 considering only overt and covert cases, respectively). Four cases have never been localized by conventional or nuclear imaging ('occult EAS'), despite an average follow-up of 5 years. CONCLUSION: The 68Ga-SSTR-PET/CT is useful in localizing EAS, especially to enhance positive prediction of the suggestive CT lesions and to detect occult neoplasms.

8.
Phys Med Biol ; 63(23): 235029, 2018 Dec 06.
Article in English | MEDLINE | ID: mdl-30520418

ABSTRACT

Dual-isotope (DI) studies offer a number of advantages in pre-clinical imaging. These include: reducing study times when compared with sequential scans, reducing the number of animals required for any given study, and most importantly, producing images perfectly registered in space and time that provide simultaneous information about two distinct body functions. The ability of single photon emission computed tomography (SPECT) to measure and differentiate energies of the emitted photons makes it well suited for DI imaging. However, since scattered photons originating from one radioisotope may be detected in the energy window of the other and thus degrade image quality and quantitative accuracy, scatter and crosstalk corrections must be applied. The decay characteristics of 111In and 67Ga, which are suitable for quantitative DI imaging for up to 2 weeks post-injection, led us to investigate the performance of simultaneous 111In/67Ga SPECT imaging using a small-animal pre-clinical scanner. A series of phantom experiments were performed to investigate image quality and accuracy of activity quantification in 111In/67Ga images acquired with three different collimators and reconstructed from different photopeak combinations. The triple energy window (TEW) method was used to correct for scatter and crosstalk. Based on these phantom studies, the optimal selection of collimator and energy window settings was determined. When using these optimal settings, submillimeter-size structures were distinguishable in the reconstructed images and quantification errors below 20% were achieved for both isotopes. The optimal parameters were subsequently applied to an in vivo animal study. The determination of the distinct pharmacokinetic profiles of two polymer radiopharmaceuticals injected simultaneously, but by different administration routes (intravenously and intraperitoneally) into a single animal demonstrated the feasibility of simultaneous 111In/67Ga SPECT.


Subject(s)
Gallium Radioisotopes/pharmacokinetics , Indium Radioisotopes/pharmacokinetics , Radiopharmaceuticals/pharmacokinetics , Tomography, Emission-Computed, Single-Photon/methods , Animals , Humans , Image Processing, Computer-Assisted/methods , Phantoms, Imaging
9.
Florianópolis; s.n; 1994. 127 p.
Thesis in Portuguese | LILACS | ID: lil-154220

ABSTRACT

Trata-se de um estudo acerca da(s) prática(s) em consulta(s) e/ou atendimento(s) de enfermagem vivenciados por mim no período de agosto de 1993 a fevereiro de 1994. Essas vivências foram preparadas sob uma base teórica na qual incluo a transaçäo como uma referência possível ou ponto de partida da relaçäo criativo-terapêutica compartilhada por enfermeira(o) e cliente na consulta e/ou atendimento. Também nessa base explicito açöes do enfermeiro como passos de um processo que incluem elementos norteadores das vivências na relaçäo de transaçäo. Além desses elementos, há outros novos que foram por mim percebidos nessas vivências do estudo. Entre esses novos elementos percebi, especialmente, olhares, sorrisos, gestos, tons de voz e formas de silêncio que se mostraram com relativa freqüência nas consultas e/ou atendimentos vivenciados. Através dessa modalidade de estudo, pude conhecer mais intimamente a consulta e/ou atendimento e reconhecer uma contribuiçäo para ampliar o mercado de trabalho dos enfermeiros


Subject(s)
Humans , Male , Female , Nursing , Nurse-Patient Relations
SELECTION OF CITATIONS
SEARCH DETAIL
...