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1.
Gen Comp Endocrinol ; 336: 114234, 2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-36791824

RESUMO

The administration of exogenous hormones emerged as an essential tool for field studies in endocrinology. However, working with wild animals remains challenging, because under field conditions not every available method meets the necessary requirements. Achieving a sustained elevation in hormone levels, while simultaneously minimising handling time and invasiveness of the procedure is a difficult task in field endocrinology. Facing this challenge, we have investigated the suitability of biocompatible polymeric microparticles, a novel method for drug-administration, as a tool to manipulate hormones in small songbirds. We chose the insulin-like growth factor-1 (IGF-1) as target hormone, because it receives great interest from the research community due to its important role in shaping life-history traits. Moreover, its short half-life and hydrophilic properties imply a major challenge in finding a suitable method to achieve a sustained, systemic long-term release. To study the release kinetics, we injected either IGF-1 loaded polylactic-co-glycolic acid (PLGA) microparticles or dispersion medium (control group) in the skin pocket of the interscapular region of captive bearded reedlings (Panurus biarmicus). We collected blood samples for 7 consecutive days plus an additional sampling period after two weeks and complemented these with an in vitro experiment. Our results show that in vitro, PLGA microparticles allowed a stable IGF-1 release for more than 15 days, following a burst release at the beginning of the measurement. In vivo, the initial burst was followed by a drop to still elevated levels in circulating IGF-1 until the effect vanished by 16 days post-treatment. This study is the first to describe the use of PLGA-microparticles as a novel tool for exogenous hormone administration in a small passerine. We suggest that this method is highly suitable to achieve the systemic long-term release of hydrophilic hormones with short half-life and reduces overall handling time, as it requires only one subcutaneous injection.


Assuntos
Ácido Láctico , Ácido Poliglicólico , Animais , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Fator de Crescimento Insulin-Like I , Hormônios
2.
Nanomedicine ; 50: 102685, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37105340

RESUMO

Urinary tract infections (UTIs) are among the most common bacterial infections. Despite a wide range of therapeutic options, treatment success is compromised by the efficient mechanism of tissue colonization of uropathogenic Escherichia coli. In advanced drug delivery systems, a similar, glycan-mediated targeting mechanism may be realized by conjugating the drug to a plant lectin, like wheat germ agglutinin (WGA). We introduce a drug delivery vehicle consisting of human serum albumin as nanoparticle shell, olive oil as core component, the active pharmaceutical ingredients (API) trimethoprim and rifampicin as well as WGA to facilitate cellular internalization. When WGA was embedded into the proteinaceous particle shell, cell binding studies revealed up to 60 % higher cell binding potential. Additionally, nanoparticles showed a good efficacy against gram-negative just as against gram-positive bacteria. The combination of the promising cell-associative properties and the proven antimicrobial potential might lead to an improved efficacy of advanced treatment of UTIs.


Assuntos
Infecções Bacterianas , Nanopartículas , Infecções Urinárias , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Albumina Sérica Humana , Sistemas de Liberação de Medicamentos , Preparações Farmacêuticas , Aglutininas do Germe de Trigo/química , Excipientes , Infecções Bacterianas/tratamento farmacológico , Nanopartículas/química , Infecções Urinárias/tratamento farmacológico
3.
Audiol Neurootol ; 24(5): 237-244, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31574511

RESUMO

INTRODUCTION: In recent years, the preservation of residual hearing has become a major factor in patients undergoing cochlear implantation (CI). In studies attempting to pharmaceutically improve hearing preservation rates, glucocorticoids (GCs) applied perioperatively in many institutions have emerged as a promising treatment regimen. Although dexamethasone is most commonly used and has been applied successfully by various research groups, recently pharmacological properties have been reported to be relatively unsuitable for topical delivery to the inner ear. Consequently other glucocorticoids merit further evaluation. The aim of this study was therefore to evaluate the otoprotective effects of the topical application of a sustained-release triamcinolone acetonide (TAAC) hydrogel in CI with hearing preservation. METHODS: Normal-hearing pigmented guinea pigs were randomized into a group receiving a single dose of a 6% TAAC poloxamer 407 hydrogel, a group receiving a 30% TAAC hydrogel and a control group. All hydrogel applications were performed 1 day prior to CI. After a cochleostomy was drilled, a specifically designed silicone electrode was inserted into the scala tympani for 5 mm. Frequency-specific compound action potentials of the auditory nerve (0.5-32 kHz) were measured pre- and directly postoperatively as well as on days 3, 7, 14, 21, and 28. Finally, temporal bones were harvested for histological evaluation. RESULTS: Application of the TAAC hydrogels resulted in significantly reduced hearing threshold shifts in low, middle and high frequencies and improved spiral ganglion cell survival in the second turn of the cochlea. Outer hair cell numbers in the basal and second turn of the cochlea were slightly reduced after TAAC application. CONCLUSION: In summary, we were able to demonstrate functional benefits of a single preoperative application of a TAAC hydrogel in a guinea pig model for CI, which persisted until the end of the observational period, that is, 28 days after surgery.


Assuntos
Implante Coclear/efeitos adversos , Implantes Cocleares , Perda Auditiva/prevenção & controle , Audição/efeitos dos fármacos , Hidrogéis/administração & dosagem , Triancinolona Acetonida/administração & dosagem , Potenciais de Ação/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Cóclea/efeitos dos fármacos , Cóclea/cirurgia , Preparações de Ação Retardada/administração & dosagem , Cobaias , Perda Auditiva/etiologia , Testes Auditivos , Gânglio Espiral da Cóclea/efeitos dos fármacos
4.
Clin Immunol ; 192: 30-39, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29608970

RESUMO

To improve current mucosal allergen immunotherapy Vibrio cholerae neuraminidase (NA) was evaluated as a novel epithelial targeting molecule for functionalization of allergen-loaded, poly(D,L-lactide-co-glycolide) (PLGA) microparticles (MPs) and compared to the previously described epithelial targeting lectins wheat germ agglutinin (WGA) and Aleuria aurantia lectin (AAL). All targeters revealed binding to Caco-2 cells, but only NA had high binding specificity to α-L fucose and monosialoganglioside-1. An increased transepithelial uptake was found for NA-MPs in a M-cell co-culture model. NA and NA-MPs induced high levels of IFN-γ and IL10 in naive mouse splenocytes and CCL20 expression in Caco-2. Repeated oral gavage of NA-MPs resulted in a modulated, allergen-specific immune response. In conclusion, NA has enhanced M-cell specificity compared to the other targeters. NA functionalized MPs induce a Th1 and T-regulatory driven immune response and avoid allergy effector cell activation. Therefore, it is a promising novel, orally applied formula for allergy therapy.


Assuntos
Proteínas de Bactérias/imunologia , Hipersensibilidade/imunologia , Fatores Imunológicos/imunologia , Doenças da Boca/imunologia , Neuraminidase/imunologia , Alérgenos/imunologia , Alérgenos/metabolismo , Alérgenos/uso terapêutico , Animais , Proteínas de Bactérias/metabolismo , Células CACO-2 , Linhagem Celular Tumoral , Técnicas de Cocultura , Dessensibilização Imunológica/métodos , Humanos , Hipersensibilidade/terapia , Camundongos Endogâmicos BALB C , Microesferas , Doenças da Boca/terapia , Neuraminidase/metabolismo , Ligação Proteica , Vibrio cholerae/enzimologia
5.
Audiol Neurootol ; 23(2): 73-81, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30092561

RESUMO

The otoprotective effects of thermoreversible poloxamer 407 hydrogels containing dexamethasone or triamcinolone acetonide were evaluated in an animal model of noise-induced hearing loss. Seven days after noise exposure, hearing threshold shifts at 16 kHz were significantly reduced in the 6% dexamethasone group (p < 0.05). Even though no significant differences in hair cell counts were found, histological analysis revealed a significantly higher spiral ganglion cell density in the first turn of the cochlea in this group (p < 0.05). No otoprotective effects were observed after the application of the triamcinolone acetonide hydrogels. As the findings of this study indicate potential otoprotective effects of sustained topical dexamethasone delivery in the setting of noise-induced hearing loss, this strategy merits further evaluation.


Assuntos
Preparações de Ação Retardada/uso terapêutico , Dexametasona/uso terapêutico , Glucocorticoides/uso terapêutico , Perda Auditiva Provocada por Ruído/tratamento farmacológico , Hidrogéis/uso terapêutico , Triancinolona Acetonida/uso terapêutico , Animais , Limiar Auditivo/efeitos dos fármacos , Cóclea/efeitos dos fármacos , Preparações de Ação Retardada/administração & dosagem , Dexametasona/administração & dosagem , Modelos Animais de Doenças , Feminino , Glucocorticoides/administração & dosagem , Cobaias , Audição/efeitos dos fármacos , Hidrogéis/administração & dosagem , Masculino , Triancinolona Acetonida/administração & dosagem
6.
J Negat Results Biomed ; 15: 10, 2016 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-27164957

RESUMO

BACKGROUND: Selective glucocorticoid receptor modulators (SEGRMs) comprise a novel class of drugs promising both reduced side effects and similar pharmacological potency relative to glucocorticoids, which presently serve as the only clinical treatment for many otologic disorders. In the first otologic SEGRM experiment in an animal model of noise trauma, we compare the effects of Compound A (a SEGRM) and dexamethasone (potent glucocorticoid). METHODS: Forty adult guinea pigs received experimental treatment once daily for ten days. The animals were divided into four cohorts based on the treatment received: Compound A (1 mg/kg or 3 mg/kg), dexamethasone (1 mg/kg) as gold standard, or water as negative control. After five applications, animals were exposed to broadband noise (8-16 kHz) at 115 dB for three hours. Hearing thresholds were determined by recording auditory brainstem responses to clicks and noise bursts (1-32 kHz) and were assessed a week prior to and immediately after exposure, as well as on days 1, 3, 7, 14, 21, and 28. Cochleae were prepared as whole-mounts or embedded and sectioned for histological analysis. RESULTS: Relative to the control treatments, Compound A failed to preserve auditory thresholds post-noise exposure with statistical significance. Histological analyses confirm the physiological result. CONCLUSION: The present findings suggest that Compound A does not have substantial otoprotective capacities in a noise trauma model.


Assuntos
Dexametasona/administração & dosagem , Ruído/efeitos adversos , Receptores de Glucocorticoides/efeitos dos fármacos , Animais , Cobaias
7.
Blood Purif ; 41(1-3): 55-63, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26488754

RESUMO

BACKGROUND/AIMS: Extracorporeal blood purification systems (EBS) use specific adsorbents for the elimination of toxins and cytokines. The aim of this study was to test different adsorbents for their ability to reduce antibiotics in parallel to extracorporeal blood purification therapy. METHODS: The in vitro adsorption experiments were carried out in human plasma with a newly established hydrophobic resin (Amberchrom CG161c) and adsorbents commercially available and approved in the clinics. The concentration of antibiotic was chosen equivalent to the recommended therapeutic dosage applied intravenously and was measured in plasma using ELISA test kits and high-performance liquid chromatography methods. RESULTS: The adsorbent that reduced all tested antibiotics in plasma close to the detection limit was the dia MARS AC250, which is an activated charcoal involved in the Molecular Adsorbents Recirculation System. CONCLUSION: For better antibiotic monitoring in sepsis treatment, further investigations have to be performed to determine the clearance rate of antibiotics by different EBS devices.


Assuntos
Antibacterianos/isolamento & purificação , Fluoroquinolonas/isolamento & purificação , Glicopeptídeos/isolamento & purificação , Desintoxicação por Sorção/instrumentação , beta-Lactamas/isolamento & purificação , Antibacterianos/sangue , Carvão Vegetal/química , Fluoroquinolonas/sangue , Glicopeptídeos/sangue , Humanos , Modelos Biológicos , Polímeros/química , Diálise Renal , Desintoxicação por Sorção/métodos , beta-Lactamas/sangue
8.
Pharm Res ; 31(3): 819-32, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24366662

RESUMO

PURPOSE: Urothelial cells, including bladder cancer (BCa) cells, represent a highly valuable but challenging target for localized antineoplastic therapy. This study describes a novel, biomimetic approach to improve intravesical drug delivery, based on glycan-specific targeting. In direct analogy to the invasion mechanism used by uropathogenic bacteria, we evaluate the potential of lectin bioconjugates to facilitate binding and uptake of large payload molecules at this penetration-hostile barrier. METHODS: Wheat germ agglutinin (WGA) served as a targeting ligand and was covalently coupled to fluorescein-labeled bovine serum albumin (fBSA), yielding multivalent protein bioconjugates. Cytoadhesion, uptake and intracellular processing were characterized on a panel of urothelial cell lines of non-malignant and malignant origin. RESULTS: Conjugation to WGA rendered the fBSA payload protein strongly cytoadhesive, with a clear preference in binding to cancerous cells. The highly specific, lectin-mediated recognition process was followed by rapid internalization, and extensive but non-exclusive accumulation in acid and LAMP-2-positive compartments. Stage of malignancy and mechano-structural cell configuration were important determinants for the sorting between different processing pathways. CONCLUSION: Lectin-bioconjugates allow for triggering endogenous uptake routes and influencing the intracellular distribution in BCa cells. They hold considerable promise for enhancing the delivery of small molecule drugs and complex biomolecules in intravesical therapy.


Assuntos
Antineoplásicos/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Soroalbumina Bovina/química , Neoplasias da Bexiga Urinária/tratamento farmacológico , Urotélio/metabolismo , Aglutininas do Germe de Trigo/química , Animais , Biomimética , Bovinos , Linhagem Celular Tumoral , Humanos , Ligação Proteica , Soroalbumina Bovina/metabolismo , Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/metabolismo , Aglutininas do Germe de Trigo/metabolismo
9.
Audiol Neurootol ; 19(3): 193-202, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24714604

RESUMO

The pharmacokinetic properties and tolerability of a triamcinolone acetonide poloxamer 407 hydrogel for intratympanic application were investigated in a guinea pig model. Evaluation of in vivo release kinetics showed very high initial perilymph drug levels, with clinically relevant levels present for a minimum of 10 days. Assessment of auditory brainstem response thresholds showed a minimal, delayed and transient threshold shift, which was apparent on day 3 and resolved by day 10. No relevant histological changes of the middle and inner ear structures were noted, and hair cell counts showed no significant differences between treated and untreated ears. Thus, the triamcinolone-acetonide-loaded poloxamer 407 hydrogel is an effective vehicle for sustained high-dose inner ear glucocorticoid delivery.


Assuntos
Preparações de Ação Retardada/farmacocinética , Glucocorticoides/farmacocinética , Hidrogéis/administração & dosagem , Triancinolona Acetonida/farmacocinética , Membrana Timpânica/efeitos dos fármacos , Animais , Preparações de Ação Retardada/administração & dosagem , Glucocorticoides/administração & dosagem , Cobaias , Hidrogéis/farmacocinética , Triancinolona Acetonida/administração & dosagem , Membrana Timpânica/metabolismo
10.
Eur J Pharm Sci ; 180: 106330, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36379358

RESUMO

After surgical removal of the tumour tissue, bladder cancer is treated by intravesical instillation of cytotoxic drugs such as gemcitabine. Gemcitabine, however, is highly hydrophilic and possesses a short half-life due to fast enzymatic deamination. Additionally, continuous dilution by urine, a hardly permeable urothelial barrier and rapid excretion by urination make therapy difficult. To modify lipophilicity of the drug, N-acyl-gemcitabine derivatives with quite different solubility and logP were synthesized, purified and characterized. The loading of PLGA nanoparticles with the N-acyl-gemcitabine derivatives followed by release in artificial urine, revealed that the drug content increases but the subsequent release decreases with lipophilicity. Additionally, acylation increased cytotoxicity and opened passive diffusion as an additional pathway into cancer cells. To address physiological constraints, the surface of the monodisperse nanoparticles was grafted with bioadhesive wheat germ agglutinin. Cytoadhesion to artificial bladder cancer tissue and even uptake into the cells as indicated by microscopic imaging are expected to prolong the retention time in the bladder cavity as well as to promote uptake into the cells. By using N-caprylic-gemcitabine as most appropriate gemcitabine-derivative for drug loading and making use of the bioadhesive characteristics of wheat germ agglutinin for grafting the corona of PLGA-nanoparticles, an innovative strategy towards smart drug delivery for instillative therapy of bladder cancer is proposed.


Assuntos
Antimetabólitos Antineoplásicos , Gencitabina , Sistemas de Liberação de Fármacos por Nanopartículas , Neoplasias da Bexiga Urinária , Aglutininas do Germe de Trigo , Humanos , Administração Intravesical , Linhagem Celular Tumoral , Desoxicitidina/administração & dosagem , Gencitabina/administração & dosagem , Gencitabina/análogos & derivados , Gencitabina/química , Neoplasias da Bexiga Urinária/tratamento farmacológico , Aglutininas do Germe de Trigo/química , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Sistemas de Liberação de Fármacos por Nanopartículas/administração & dosagem , Sistemas de Liberação de Fármacos por Nanopartículas/química
11.
Eur J Hosp Pharm ; 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38050051

RESUMO

OBJECTIVES: The aim of this project was to develop a rectal formulation of metyrapone suitable for application in an infant hospitalised with McCune-Albright syndrome (MAS)-related Cushing syndrome and to provide a detailed description of the formulation protocol including quality control parameters. METHODS: Suppositories with a drug load of up to 100 mg metyrapone were prepared. Mass variation, content uniformity and drug release were analysed according to the guidelines set out by the European Pharmacopoeia. Monitoring of the drug content for 6 weeks allowed for estimation of the storage stability at 2-8°C. RESULTS: A protocol for the reproducible preparation of suppositories with intended metyrapone content of 30-100 mg was established. The suppositories were well tolerated by the patient and the clinical outcome is promising. The suppository preparations complied with the regulations from the European Pharmacopoeia. Further, a stability of the rectal formulation of at least 1 month was confirmed, facilitating medication supply for home care. CONCLUSIONS: An adequate and easy to follow protocol for preparation of high-quality metyrapone suppositories, with sufficient stability for practical use and fulfilling major pharmaceutical quality parameters, was established. The protocol can be easily replicated by skilled personnel in a community pharmacy facilitating treatment of the infant in home care.

12.
Pharmaceutics ; 15(5)2023 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-37242645

RESUMO

Background: Most frequently the functionalization of nanoparticles is hampered by time-consuming, sometimes harsh conjugation and purification procedures causing premature drug release and/or degradation. A strategy to circumvent multi-step protocols is to synthesize building blocks with different functionalities and to use mixtures thereof for nanoparticle preparation in one step. Methods: BrijS20 was converted into an amine derivative via a carbamate linkage. The Brij-amine readily reacts with pre-activated carboxyl-containing ligands such as folic acid. The structures of the building blocks were confirmed by different spectroscopic methods and their utility was assessed by one-step preparation and characterization of nanoparticles applying PLGA as a matrix polymer. Results: Nanoparticles were about 200 nm in diameter independent of the composition. Experiments with human folate expressing single cells and monolayer revealed that the nanoparticle building block Brij mediates a "stealth" effect and the Brij-amine-folate a "targeting" effect. As compared to plain nanoparticles, the stealth effect decreased the cell interaction by 13%, but the targeting effect increased the cell interaction by 45% in the monolayer. Moreover, the targeting ligand density and thus the cell association of the nanoparticles is easily fine-tuned by selection of the initial ratio of the building blocks. Conclusions: This strategy might be a first step towards the one-step preparation of nanoparticles with tailored functionalities. Relying on a non-ionic surfactant is a versatile approach as it might be extended to other hydrophobic matrix polymers and promising targeting ligands from the biotech pipeline.

13.
Pharmaceutics ; 15(3)2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36986834

RESUMO

To shed some light on glycotargeting as a potential strategy for nasal drug delivery, a reliable preparation method for human nasal mucosa samples and a tool to investigate the carbohydrate building blocks of the glycocalyx of the respiratory epithelium are required. Applying a simple experimental setup in a 96-well plate format together with a panel of six fluorescein-labeled lectins with different carbohydrate specificities allowed for the detection and quantification of accessible carbohydrates in the mucosa. As confirmed by binding experiments at 4 °C, both quantitatively by fluorimetry and qualitatively by microscopy, the binding of wheat germ agglutinin exceeded that of the others by 150% on average, indicating a high content of N-acetyl-D-glucosamine and sialic acid. Providing energy by raising the temperature to 37 °C revealed uptake of the carbohydrate-bound lectin into the cell. Moreover, repeated washing steps during the assay gave a slight hint as to the influence of mucus renewal on bioadhesive drug delivery. All in all, the experimental setup reported here for the first time is not only a suitable approach to estimating the basics and potential of nasal lectin-mediated drug delivery but also meets the needs for answering a broad variety of scientific questions involving the use of ex vivo tissue samples.

14.
Horm Res Paediatr ; 2023 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-38008082

RESUMO

A female toddler was diagnosed at age ten months with peripheral precocious puberty and hypercortisolism related to McCune Albright Syndrome with additional systemic complications. We present the first successful, long-term use of metyrapone as suppositories, with striking clinical and biochemical improvement and no side-effects.

15.
Eur J Pharm Biopharm ; 170: 52-58, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34864199

RESUMO

Intratympanically applied treatments are of increasing interest to the otologic community to treat sudden sensorineural hearing loss or vestibular disorders but also to deliver gene therapy agents, or biologics to the inner ear. Further diversion from the middle ear and perilymph to blood circulation and cerebrospinal fluid via the cochlear aqueduct are one of the limiting factors and so far not understood well enough. In this study, intratympanically applied triamcinolone acetonide was determined in cerebrospinal fluid. Additionally, perilymph was sampled through the round window membrane as well as at the lateral semicircular canal to determine drug levels. Of the twenty-one included patients, triamcinolone acetonide was quantifiable in cerebrospinal fluid in 43% at very low levels (range 0 ng/ml-6.2 ng/ml) which did not correlate with perilymph levels. Drug levels at the two different perilymph sampling sites were within a range of 13.5 ng/ml to 1180.0 ng/ml. Results suggest an equal distribution of triamcinolone acetonide to semicircular canals, which might support the use of triamcinolone acetonide as a treatment option for vestibular pathologies such as Menièrés disease. On the other hand, the distribution to cerebrospinal fluid might be limiting current approaches in gene therapy where a central distribution is unwanted.


Assuntos
Líquido Cefalorraquidiano/metabolismo , Glucocorticoides/administração & dosagem , Neuroma Acústico/tratamento farmacológico , Triancinolona Acetonida/administração & dosagem , Feminino , Humanos , Injeção Intratimpânica , Masculino , Pessoa de Meia-Idade , Perilinfa/metabolismo
16.
J Urol ; 186(4): 1481-8, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21855917

RESUMO

PURPOSE: Inadequate urothelial delivery of drugs is considered a primary cause of current shortcomings in adjuvant intravesical chemotherapy for bladder cancer. We report what is to our knowledge a novel biorecognitive approach to achieve more regionally selective targeting of malignant tissue and improve urothelial uptake based on specific interaction between lectins and bladder cell glycocalyces. MATERIALS AND METHODS: We assessed the cytoadhesive and cytoinvasive potential of selected plant lectins in 3 human urothelial cell lines, corresponding to healthy tissue, and low and high grade carcinoma, respectively. Flow cytometry and fluorimetry were used to determine binding capacity and specificity in single cells and confluent monolayers. Monensin quenching experiments, microscopic analysis and enzyme treatment allowed further characterization of internalization, the uptake pathway and the potential cause of tumor selectivity. RESULTS: Wheat germ agglutinin had the highest bioadhesive potential while peanut agglutinin was the most potent discriminator between healthy and cancerous tissue (p <0.01). In each case cell interaction was highly specific (greater than 80%) and proved decisive for efficient uptake. Within 60 minutes after exposure greater than 50% of membrane bound lectins were internalized in acidic compartments. Cancer associated aberrant glycosylation likely represents the determining cause of peanut agglutinin selectivity. CONCLUSIONS: Given careful choice of the targeting ligand, the development of carbohydrate based delivery strategies for bladder cancer therapy seems feasible. Lectin bioadhesion may not only mediate preferential accumulation in malignant tissue but also promote cellular internalization via increased recruitment of membrane bound material to physiological uptake routes.


Assuntos
Carcinoma de Células de Transição/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Lectinas de Plantas , Neoplasias da Bexiga Urinária/tratamento farmacológico , Administração Intravesical , Linhagem Celular Tumoral , Citometria de Fluxo , Humanos , Microscopia de Fluorescência , Monensin/farmacologia , Lectinas de Plantas/metabolismo , Células Tumorais Cultivadas , Urotélio/metabolismo
17.
Ultrason Sonochem ; 79: 105783, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34653915

RESUMO

Although therapeutically active proteins are highly efficacious, their content in protective nanoparticles is often too low to elicit adequate plasma levels. A strategy to increase protein loading is the in-situ generation of calcium phosphate as a protein adsorbent. To verify this approach, a highly sensitive and reliable fluorimetric method for quantification of incorporated fluorescein-labelled bovine serum albumin (FITC-BSA) as a model protein drug was developed. Dequenching the fluorescein label by pronase E, which digests the protein backbone, and dissolving the nanoparticle matrix in acetonitrile enabled FITC-BSA quantification in the nanogram per milliliter range. This test was confirmed by a second assay involving alkaline hydrolysis of FITC-BSA and the matrix. Nanoparticles prepared with calcium phosphate contained 40 µg FITC-BSA/mg and nanoparticles without calcium phosphate only 15 µg FITC-BSA/mg, representing a 2.7-fold increase in model protein loading. In this work the nanoparticle preparation procedure was optimized in terms of size for administration in the inner ear, but the range of applications is not limited.


Assuntos
Orelha Interna , Nanopartículas , Fosfatos de Cálcio , Fluoresceína-5-Isotiocianato/análogos & derivados , Preparações Farmacêuticas , Soroalbumina Bovina
18.
Ultrason Sonochem ; 76: 105617, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34126523

RESUMO

The focus of this study is the preparation of proteinaceous human serum albumin (HSA) nanocapsules with biocompatible plant oil cores avoiding toxic cross-linker and noxious non-aqueous liquids. The sonochemical preparation of HSA capsules with different plant oils yields particles with narrow size distribution forming suspensions stable for at least 14 days and enabling long-term storage by freezing. Furthermore, wheat germ agglutinin (WGA) as a targeting molecule was successfully embedded into the proteinaceous particle shell at a molar ratio of 7:1 (HSA/WGA). As urothelial cell binding studies revealed up to 55% higher cell binding potential of WGA-grafted particles than those without a targeter, targeted protein nanocapsules represent the first step towards new and innovative formulations.


Assuntos
Portadores de Fármacos/química , Nanocápsulas/química , Óleos de Plantas/química , Albumina Sérica Humana/química , Ondas Ultrassônicas , Humanos
19.
JAMA Otolaryngol Head Neck Surg ; 147(11): 974-980, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34591079

RESUMO

Importance: The use of intratympanically applied steroids is of increasing interest. Consequently, research has focused on finding an ideal drug that diffuses through the round window membrane and can be retained in the perilymph. Objective: To compare levels of triamcinolone acetonide (TAC) in perilymph and plasma after intratympanic injection. Design, Setting, and Participants: This randomized clinical trial included 40 patients receiving cochlear implants at a single tertiary care center in Vienna, Austria. Patients were randomized to 1 of 4 treatment groups receiving 1 of 2 intratympanic doses of TAC (10 mg/mL or 40 mg/mL) at 1 of 2 approximate time points (24 hours or 1 hour) before sampling the perilymph. Inclusion was carried out between November 2017 and January 2020, and data were analyzed in December 2020. Interventions: All patients underwent intratympanic injection of TAC. During cochlear implantation, perilymph and plasma were sampled for further analysis. Main Outcomes and Measures: Levels of TAC measured in perilymph and plasma. Results: Among the 37 patients (median [range] age, 57 [26-88] years; 18 [49%] men) included in the analysis, TAC was present at a median (range) level of 796.0 (46.4-7706.7) ng/mL. In the majority of patients (n = 29; 78%), no drug was detectable in the plasma after intratympanic injection. Levels above the limit of detection were less than 2.5 ng/mL. The 1-factorial analysis of variance model showed lower TAC levels in the group that received TAC, 10 mg/mL, 24 hours before surgery (median, 271 ng/mL) compared with the group that received TAC, 10 mg/mL, 1 hour before surgery (median, 2877 ng/mL), as well as in comparison with the groups receiving TAC, 40 mg/mL, 24 hours before surgery (median, 2150 ng/mL) and 1 hour before surgery (median, 939 ng/mL). The 2-factorial analysis of variance model showed lower TAC levels in the group receiving TAC, 10 mg/mL, 24 hours before surgery than the group receiving TAC, 10 mg/mL, 1 hour before surgery, and higher TAC levels in the group receiving TAC, 40 mg/mL, 24 hours before surgery compared with the group receiving TAC, 10 mg/mL, 24 hours before surgery. Patients with thickening of the middle ear had statistically significantly higher plasma levels (median, 1.4 ng/mL vs 0 ng/mL) and lower perilymph levels (median, 213.1 ng/mL vs 904 ng/mL) than individuals with unremarkable middle ear mucosa. Conclusions and Relevance: In this randomized clinical trial, TAC was shown to be a promising drug for intratympanic therapies, with similar levels in perilymph 1 hour and 24 hours after injection (distinctly in the groups receiving the 40 mg/mL dose). There was also minimal dissemination to the plasma, especially in patients with unremarkable middle ear mucosa. Trial Registration: ClinicalTrials.gov Identifier: NCT03248856.


Assuntos
Anti-Inflamatórios/farmacocinética , Implante Coclear , Perilinfa/química , Cuidados Pré-Operatórios/métodos , Triancinolona Acetonida/farmacocinética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/metabolismo , Esquema de Medicação , Feminino , Humanos , Injeção Intratimpânica , Masculino , Pessoa de Meia-Idade , Triancinolona Acetonida/administração & dosagem , Triancinolona Acetonida/metabolismo , Adulto Jovem
20.
Carbohydr Polym ; 252: 117091, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33183582

RESUMO

This study investigates a novel preparation technique for pellets made from acetylated inulin and their characterization focusing on specific intestinal delivery of 5-aminosalicylic acid. By means of acetylation the hydrophobicity of four native inulins was increased yielding materials with selected degrees of acetylation. The acetylated inulins were insoluble in water, which was confirmed by the log P-values ranging from 1.30 to 1.58. 5-Aminosalicylic acid loading capacity of the pellets was up to 60 % and high enough to match the therapeutic range of the anti-inflammatory drug. Depending on the 5-aminosalicylic acid content and the type of acetylated inulin, up to 80 % of the entrapped drug was released within 24 h in intestinal environment under in-vitro conditions. Here we successfully prepared chemically modified and profoundly characterized inulin to provide innovative formulations and to open up a promising new strategy for treatment of Morbus Crohn and ulcerative colitis.


Assuntos
Anti-Inflamatórios/química , Portadores de Fármacos/química , Inulina/química , Mesalamina/química , Anti-Inflamatórios/administração & dosagem , Liberação Controlada de Fármacos , Humanos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Mesalamina/administração & dosagem
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