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1.
Int Braz J Urol ; 50(2): 227-228, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38386794

RESUMO

BACKGROUND: The ectopic pelvic kidney, a common renal anomaly, is often smaller and malformed, with a shorter and sometimes tortuous ureter (1). Muscle-invasive bladder cancer (MIBC), constituting 15-25% of bladder cancer cases (2), mandates radical cystectomy with a 50% 5-year survival rate (2). Despite the growing use of robot-assisted radical cystectomy (RARC) (3, 4), there is limited data on its application in ectopic kidneys. Only one RARC case has been reported (5), in contrast to numerous open radical cystectomies (1, 6) involving an ectopic kidney. PATIENT AND METHODS: After being diagnosed with T2 high-grade urothelial carcinoma, the 66-year-old patient, previously treated with multiple transurethral resections and adjuvant BCG therapy, received neoadjuvant chemotherapy. Preoperative staging CT revealed a 2.6 x 2.2 cm bladder neoformation and an ectopic right pelvic kidney. RESULTS: Using the da Vinci Surgical System, radical cystectomy with ileal conduit (sec Wallace II) and lymphadenectomy were performed. During the demolition phase, the shorter right ureter was dissected with care to avoid damage to the renal pedicle. The reconstructive phase included intracorporeal urinary diversion (ICUD) and uretero-ileal anastomosis, facilitated by the favorable position of the kidney. The 8-hour console surgery resulted in minimal blood loss. Discharged on day 16 due to COVID-19, the patient exhibited positive outcomes. A 2-month CT follow-up revealed no cancer recurrence, metastasis, hydronephrosis, and complete regression of the lymphocele. Imaging follow-up continues without postoperative adjuvant chemotherapy. CONCLUSION: Robotic surgery with intracorporeal urinary diversion holds potential for right-sided pelvic kidney cases, but additional studies are necessary for validation.


Assuntos
Carcinoma de Células de Transição , Robótica , Neoplasias da Bexiga Urinária , Derivação Urinária , Humanos , Idoso , Cistectomia , Estudos de Viabilidade , Neoplasias da Bexiga Urinária/cirurgia , Recidiva Local de Neoplasia , Rim/cirurgia
2.
Appl Microbiol Biotechnol ; 107(11): 3763-3778, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37079062

RESUMO

The resistance development is an increasing global health risk that needs innovative solutions. Repurposing drugs to serve as anti-virulence agents is suggested as an advantageous strategy to diminish bacterial resistance development. Bacterial virulence is controlled by quorum sensing (QS) system that orchestrates the expression of biofilm formation, motility, and virulence factors production as enzymes and virulent pigments. Interfering with QS could lead to bacterial virulence mitigation without affecting bacterial growth that does not result in bacterial resistance development. This study investigated the probable anti-virulence and anti-QS activities of α-adrenoreceptor blocker doxazosin against Proteus mirabilis and Pseudomonas aeruginosa. Besides in silico study, in vitro and in vivo investigations were conducted to assess the doxazosin anti-virulence actions. Doxazosin significantly diminished the biofilm formation and release of QS-controlled Chromobacterium violaceum pigment and virulence factors in P. aeruginosa and P. mirabilis, and downregulated the QS encoding genes in P. aeruginosa. Virtually, doxazosin interfered with QS proteins, and in vivo protected mice against P. mirabilis and P. aeruginosa. The role of the membranal sensors as QseC and PmrA was recognized in enhancing the Gram-negative virulence. Doxazosin downregulated the membranal sensors PmR and QseC encoding genes and could in silico interfere with them. In conclusion, this study preliminary documents the probable anti-QS and anti-virulence activities of doxazosin, which indicate its possible application as an alternative or in addition to antibiotics. However, extended toxicological and pharmacological investigations are essential to approve the feasible clinical application of doxazosin as novel efficient anti-virulence agent. KEY POINTS: • Anti-hypertensive doxazosin acquires anti-quorum sensing activities • Doxazosin diminishes the virulence of Proteus mirabilis and Pseudomonas aeruginosa • Doxazosin could dimmish the bacterial espionage.


Assuntos
Biofilmes , Fatores de Virulência , Camundongos , Animais , Fatores de Virulência/metabolismo , Doxazossina/farmacologia , Reposicionamento de Medicamentos , Percepção de Quorum , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Pseudomonas aeruginosa/metabolismo
3.
Int J Urol ; 30(3): 308-317, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36478459

RESUMO

OBJECTIVE: To externally validate Yonsei nomogram. METHODS: From 2000 through 2018, 3526 consecutive patients underwent on-clamp PN for cT1 renal masses at 23 centers were included. All patients had two kidneys, preoperative eGFR ≥60 ml/min/1.73 m2, and a minimum follow-up of 12 months. New-onset CKD was defined as upgrading from CKD stage I or II into CKD stage ≥III. We obtained the CKD-free progression probabilities at 1, 3, 5, and 10 years for all patients by applying the nomogram found at https://eservices.ksmc.med.sa/ckd/. Thereafter, external validation of Yonsei nomogram for estimating new-onset CKD stage ≥III was assessed by calibration and discrimination analysis. RESULTS AND LIMITATION: Median values of patients' age, tumor size, eGFR and follow-up period were 47 years (IQR: 47-62), 3.3 cm (IQR: 2.5-4.2), 90.5 ml/min/1.73 m2 (IQR: 82.8-98), and 47 months (IQR: 27-65), respectively. A total of 683 patients (19.4%) developed new-onset CKD. The 5-year CKD-free progression rate was 77.9%. Yonsei nomogram demonstrated an AUC of 0.69, 0.72, 0.77, and 0.78 for the prediction of CKD stage ≥III at 1, 3, 5, and 10 years, respectively. The calibration plots at 1, 3, 5, and 10 years showed that the model was well calibrated with calibration slope values of 0.77, 0.83, 0.76, and 0.75, respectively. Retrospective database collection is a limitation of our study. CONCLUSIONS: The largest external validation of Yonsei nomogram showed good calibration properties. The nomogram can provide an accurate estimate of the individual risk of CKD-free progression on long-term follow-up.


Assuntos
Neoplasias Renais , Insuficiência Renal Crônica , Humanos , Pessoa de Meia-Idade , Nomogramas , Neoplasias Renais/patologia , Estudos Retrospectivos , Insuficiência Renal Crônica/cirurgia , Nefrectomia/métodos , Taxa de Filtração Glomerular
4.
Chem Biodivers ; 20(11): e202301208, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37775474

RESUMO

A new monoalkyl glycerol ether, 3-(n-henicosyloxy)propane-1,2-diol (1), was isolated from the CH2 Cl2 /MeOH crude extract of the Red Sea soft coral Nephthea mollis. Additionally, three known related analogs were identified: chimyl alcohol (2), batyl alcohol (3), and 3-(icosyloxy)propane-1,2-diol (4). The chemical structure of 3-(n-henicosyloxy)propane-1,2-diol was determined using advanced spectroscopic analyses, including 1D, 2D Nuclear Magnetic Resonance (NMR), Electron Ionization mass spectra (EI-MS), and High-Resolution Electron Spray Ionization mass spectra (HR-ESI-MS) analyses. Furthermore, the identification of chimyl alcohol, batyl alcohol and 3-(icosyloxy)propane-1,2-diol was achieved by studying their EI mass fragmentation analyses and comparing their mass data with those previously reported in the literature. The cytotoxic activity of the Nephthea mollis crude extract and 3-(n-henicosyloxy)propane-1,2-diol was evaluated against five human cancer cell lines: HepG2 (hepatocellular carcinoma), MCF-7 (breast carcinoma), NCI-1299 (lung carcinoma), HeLa (cervical cancer cell), and HT-29 (colon adenocarcinoma). Moreover, 3-(n-henicosyloxy)propane-1,2-diol revealed moderate cytotoxicity against the HeLa cell lines with an IC50 value of 24.1 µM, while showing inactivity against the remaining cell lines (IC50 >100 µM).


Assuntos
Adenocarcinoma , Antozoários , Antineoplásicos , Neoplasias do Colo , Animais , Humanos , Células HeLa , Éter , Glicerol/metabolismo , Antozoários/química , Propano , Oceano Índico , Éteres de Glicerila/metabolismo , Antineoplásicos/química , Etil-Éteres/metabolismo , Éteres , Misturas Complexas/metabolismo , Linhagem Celular Tumoral
5.
Int J Mol Sci ; 23(21)2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36361877

RESUMO

The development of bacterial resistance to antibiotics is an increasing public health issue that worsens with the formation of biofilms. Quorum sensing (QS) orchestrates the bacterial virulence and controls the formation of biofilm. Targeting bacterial virulence is promising approach to overcome the resistance increment to antibiotics. In a previous detailed in silico study, the anti-QS activities of twenty-two ß-adrenoreceptor blockers were screened supposing atenolol as a promising candidate. The current study aims to evaluate the anti-QS, anti-biofilm and anti-virulence activities of the ß-adrenoreceptor blocker atenolol against Gram-negative bacteria Serratia marcescens, Pseudomonas aeruginosa, and Proteus mirabilis. An in silico study was conducted to evaluate the binding affinity of atenolol to S. marcescens SmaR QS receptor, P. aeruginosa QscR QS receptor, and P. mirabilis MrpH adhesin. The atenolol anti-virulence activity was evaluated against the tested strains in vitro and in vivo. The present finding shows considerable ability of atenolol to compete with QS proteins and significantly downregulated the expression of QS- and virulence-encoding genes. Atenolol showed significant reduction in the tested bacterial biofilm formation, virulence enzyme production, and motility. Furthermore, atenolol significantly diminished the bacterial capacity for killing and protected mice. In conclusion, atenolol has potential anti-QS and anti-virulence activities against S. marcescens, P. aeruginosa, and P. mirabilis and can be used as an adjuvant in treatment of aggressive bacterial infections.


Assuntos
Atenolol , Fatores de Virulência , Camundongos , Animais , Atenolol/farmacologia , Atenolol/metabolismo , Fatores de Virulência/genética , Percepção de Quorum , Biofilmes , Bactérias Gram-Negativas , Pseudomonas aeruginosa , Serratia marcescens/metabolismo , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Proteus mirabilis/metabolismo , Proteínas de Bactérias/metabolismo
6.
World J Urol ; 39(9): 3465-3471, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33538866

RESUMO

INTRODUCTION: Telementoring is one of the applications of telemedicine capable of bringing highly experienced surgeons to areas lacking expertise. In the current study, we aimed to assess a novel telementoring application during the learning curve of transurethral enucleation of the prostate using bipolar energy (TUEB). MATERIAL AND METHODS: A telementoring system was developed by our engineering department. This application was used to mentor ten prospective cases of TUEB performed by an expert endourologist (novice to the TUEB). A questionnaire was filled by the operating surgeon and the mentor to provide subjective evaluation of the telementoring system. Finally, the outcomes of these patients were compared to a control group consisting of ten consecutive patients performed by the mentor. RESULTS: Ten consecutive TUEB were performed using this telementoring application. Delayed and interrupted connection were experienced in two and one patients, respectively; however, their effect was minor, and they did not compromise the safety of the procedure. None of the patients required conversion to conventional transurethral resection of the prostate. Only one patient in our series experienced grade IIIb complication. CONCLUSION: The telementoring application for TUEB is promising. It is a simple and low-cost tool that could be a feasible option to ensure patients' safety during the initial phase of the learning curve without time and locations constraints for both the mentor and the trainee; However, it should be mentioned that telementoring cannot yet replace the traditional surgical training with the mentor and trainee being in the operative room. Further studies are required to confirm the current results.


Assuntos
Educação a Distância , Eletrocirurgia , Tutoria/métodos , Hiperplasia Prostática/cirurgia , Ressecção Transuretral da Próstata/educação , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Humanos , Curva de Aprendizado , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos
7.
BJU Int ; 125(5): 656-663, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32012426

RESUMO

OBJECTIVE: The aim of the paper is to provide an overview of intraoperative sampling methods for frozen section (FS) analysis and of surgical techniques for a secondary neurovascular bundle (NVB) resection, as the method of surgical margin (SM) sampling and the management of a positive SM (PSM) at the nerve-sparing (NS) area are under evaluated issues. FS analysis during radical prostatectomy (RP) can help to tailor the plane of dissection based on cancer extension and thus extend the indications for NS surgery. EVIDENCE ACQUISITION: We performed a PubMed/Medical Literature Analysis and Retrieval System Online (MEDLINE), Web of Science, Cochrane Library, and Elton B. Stephens Co. (EBSCO)host search to include articles published in the last decade, evaluating FS analysis in the NS area and surgical attempts to convert a PSM to a negative status. EVIDENCE SYNTHESIS: Overall, 19 papers met our inclusion criteria. The ways to collect samples for FS analysis included: systematic (analysing the whole posterolateral aspect of the prostate specimen, i.e., neurovascular structure-adjacent frozen-section examination [NeuroSAFE]); magnetic resonance imaging (MRI)-guided (biopsies from MRI-suspicious areas, retrieved by the surgeon in a cognitive way); and random biopsies from the soft periprostatic tissues. Techniques to address a PSM in the NS area included: full resection of the spared NVB, from its caudal to cranial aspect, often including the rectolateral part of the Denonvilliers' fascia; partial resection of the NVB, in cases where sampling attempts to localise a PSM; incremental approach, meaning a partial or full resection that extends until no prostate tissue is found in the soft periprostatic environment. CONCLUSIONS: There is no homogeneity in prostate sampling for FS analysis, although most recent evidence is moving toward a systematic sampling of the entire NS area. The management of a PSM is variable and can be affected by the sampling strategy (difficult localisation of the persisting tumour at the NVB). The difficult identification of the exact soft tissue location contiguous to a PSM could be considered as the critical point of FS analysis and of spared-NVB management.


Assuntos
Margens de Excisão , Estadiamento de Neoplasias , Próstata/patologia , Prostatectomia/métodos , Neoplasias da Próstata/cirurgia , Humanos , Biópsia Guiada por Imagem/métodos , Período Intraoperatório , Masculino , Próstata/cirurgia , Neoplasias da Próstata/patologia , Reoperação
8.
BJU Int ; 125(6): E7-E14, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32249538

RESUMO

OBJECTIVE: To discuss the impact of COVID-19 on global health, particularly on urological practice and to review some of the available recommendations reported in the literature. MATERIAL AND METHODS: In the current narrative review the PubMed database was searched to identify all the related reports discussing the impact of COVID-19 on the urological field. RESULTS: The COVID-19 pandemic is the latest and biggest global health threat. Medical and surgical priorities have changed dramatically to cope with the current challenge. These changes include postponements of all elective outpatient visits and surgical procedures to save facilities and resources for urgent cases and patients with COVID-19 patients. This review discuss some of the related changes in urology. CONCLUSIONS: Over the coming weeks, healthcare workers including urologists will be facing increasingly difficult challenges, and consequently, they should adopt triage strategy to avoid wasting of medical resources and they should endorse sufficient protection policies to guard against infection when dealing with COVID-19 patients.


Assuntos
Infecções por Coronavirus/epidemiologia , Pandemias , Pneumonia Viral/epidemiologia , Procedimentos Cirúrgicos Urológicos , Betacoronavirus/fisiologia , COVID-19 , Procedimentos Cirúrgicos Eletivos , Saúde Global , Humanos , SARS-CoV-2 , Triagem , Sistema Urinário/microbiologia
9.
J Minim Invasive Gynecol ; 27(4): 847-853, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31377456

RESUMO

STUDY OBJECTIVE: To evaluate the efficacy of vaginal dinoprostone in reducing pain perception during diagnostic office hysteroscopy (OH) in postmenopausal women. DESIGN: Randomized, double-blind controlled trial. SETTING: Tertiary university hospital. PARTICIPANTS: Postmenopausal patients scheduled for OH. INTERVENTIONS: Eligible participants were randomized in a 1:1 ratio to the dinoprostone and placebo groups. The severity of pain was assessed with a visual analog scale (VAS) ranging from 0, no pain to 10, worst pain during OH and 30 minutes after OH. MEASUREMENTS AND MAIN RESULTS: The difference in the intensity of pain using the VAS score during the procedure. One hundred women (50 in each arm) were included in the study. The mean VAS score during OH was significantly lower in the dinoprostone group compared with the placebo group (3.9 ± 0.8 vs 5.6 ± 0.7; p <.001). The passage of the hysteroscope through the cervical canal was easier in the dinoprostone group (62.4 ± 9.5 vs 42.8 ± 10.8; p <.001). The 2 groups were comparable in terms of the duration of the procedure (p = .91) and the rate of adverse effects. CONCLUSION: Vaginal dinoprostone is effective in relieving pain during diagnostic OH in postmenopausal women with few adverse effects.


Assuntos
Histeroscopia , Misoprostol , Dinoprostona/uso terapêutico , Método Duplo-Cego , Feminino , Humanos , Histeroscopia/efeitos adversos , Histeroscopia/métodos , Dor/etiologia , Percepção da Dor , Pós-Menopausa , Gravidez
10.
J Card Surg ; 35(8): 2053-2055, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32652732

RESUMO

Colonoscopy is generally considered a safe procedure, with a low rate of complications. Although rare, the migration of the colonoscope may represent life-threatening events, requiring emergency treatment. We, herein, describe the case of an elective colonoscopy complicated by an irretrievable colonoscope that migrated, through a previous traumatic diaphragmatic hernia, in the chest cavity. This hernia was likely a chronic complication of a previous abdominal trauma. Several attempts to retrieve the scope were unsuccessful. After further investigations and collegial discussion, a left thoracotomy was performed, with the aim to retrieve the colonoscope and to reduce the hernia.


Assuntos
Colonoscópios/efeitos adversos , Colonoscopia/efeitos adversos , Corpos Estranhos/cirurgia , Migração de Corpo Estranho/cirurgia , Cavidade Torácica , Toracotomia/métodos , Traumatismos Abdominais/complicações , Idoso , Hérnia Diafragmática/etiologia , Humanos , Masculino
11.
BJU Int ; 124(3): 469-476, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30908852

RESUMO

OBJECTIVE: To report the first application of ex vivo fluorescence confocal microscopy (FCM) - a novel optical technology that is capable of providing fast microscopic imaging of unfixed tissue specimens- in the urological field assessing its diagnostic accuracy for non neoplastic and cancerous prostate tissue (prostatic adenocarcinoma) compared to the 'gold standard' histopathological diagnoses. PATIENTS AND METHODS: In all, 89 specimens from 13 patients with clinically localised prostate cancer were enrolled into the study. All patients underwent robot-assisted laparoscopic radical prostatectomy with fresh prostatic tissue biopsies taken at the end of each intervention using an 18-G biopsy punch. Specimens were randomly assigned to the three collaborating pathologists for evaluation. Intra- and inter-observer agreement was tested by the means of Cohen's κ. The diagnostic performance was evaluated on receiver operating characteristic curve analysis. RESULTS: The overall diagnostic agreement between FCM and histopathological diagnoses was substantial with a 91% correct diagnosis (κ = 0.75) and an area under the curve of 0.884 (95% confidence interval 0.840-0.920), 83.33% sensitivity, and 93.53% specificity. CONCLUSION: FCM seems to be a promising tool for enhanced specimens' reporting performance, given its simple application and very rapid microscopic image generation (<5 min/specimen). This technique may potentially be used for intraoperative pathological specimens' analysis.


Assuntos
Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Próstata , Prostatectomia/métodos , Neoplasias da Próstata , Idoso , Biópsia , Humanos , Cuidados Intraoperatórios , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Próstata/diagnóstico por imagem , Próstata/patologia , Próstata/cirurgia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Curva ROC , Procedimentos Cirúrgicos Robóticos/métodos
12.
Biomacromolecules ; 20(3): 1297-1307, 2019 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-30694656

RESUMO

A synthetic cell mimic in the form of giant glycosylated polymersomes (GGPs) comprised of a novel amphiphilic diblock copolymer is reported. A synthetic approach involving a poly(dimethylsiloxane) (PDMS) macro-chain transfer agent (macroCTA) and postpolymerization modification was used to marry the hydrophobic and highly flexible properties of PDMS with the biological activity of glycopolymers. 2-Bromoethyl acrylate (BEA) was first polymerized using a PDMS macroCTA ( Mn,th ≈ 4900 g·mol-1, D = 1.1) to prepare well-defined PDMS- b-pBEA diblock copolymers ( D = 1.1) that were then substituted with 1-thio-ß-d-glucose or 1-thio-ß-d-galactose under facile conditions to yield PDMS- b-glycopolymers. Compositions possessing ≈25% of the glycopolymer block (by mass) were able to adopt a vesicular morphology in aqueous solution (≈210 nm in diameter), as indicated by TEM and light scattering techniques. The resulting carbohydrate-decorated polymersomes exhibited selective binding with the lectin concanavalin A (Con A), as demonstrated by turbidimetric experiments. Self-assembly of the same diblock copolymer compositions using an electroformation method yielded GGPs (ranging from 2-20 µm in diameter). Interaction of these cell-sized polymersomes with fimH positive E. coli was then studied via confocal microscopy. The glucose-decorated GGPs were found to cluster upon addition of the bacteria, while galactose-decorated GGPs could successfully interact with (and possibly immobilize) the bacteria without the onset of clustering. This demonstrates an opportunity to modulate the response of these synthetic cell mimics (protocells) toward biological entities through exploitation of selective ligand-receptor interactions, which may be readily tuned through a considered choice of carbohydrate functionality.


Assuntos
Dimetilpolisiloxanos/química , Escherichia coli/química , Polímeros/química , Glicosilação , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Transmissão , Nefelometria e Turbidimetria , Espalhamento de Radiação
13.
Biomacromolecules ; 19(8): 3343-3350, 2018 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-29928802

RESUMO

Novel approaches for culturing primary human cells in vitro are increasingly needed to study cell and tissue physiology and to grow replacement tissue for regenerative medicine. Conventional 2D monolayer cultures of endometrial epithelial and stromal cells fail to replicate the complex 3D architecture of tissue. A fully synthetic scaffold that mimics the microenvironment of the human endometrium can ultimately provide a robust platform for investigating tissue physiology and, hence, take significant steps toward tackling female infertility and IVF failure. In this work, emulsion-templated porous polymers (known as polyHIPEs) were investigated as scaffolds for the culture of primary human endometrial epithelial and stromal cells (HEECs and HESCs). Infiltration of HEECs and HESCs into cell-seeded polyHIPE scaffolds was assessed by histological studies, and phenotype was confirmed by immunostaining. Confocal microscopy revealed that the morphology of HEECs and HESCs is representative of that found in vivo. RNA sequencing was used to investigate transcriptome differences between cells grown on polyHIPE scaffolds and in monolayer cultures. The differentiation status of HEECs and HESCs grown in polyHIPE scaffolds and in monolayer cultures was further evaluated by monitoring the expression of endometrial marker genes. Our observations suggest that a 3D cell culture model that could approximate native human endometrial architecture and function can be developed using tailored polyHIPE scaffolds.


Assuntos
Diferenciação Celular , Endométrio/citologia , Polímeros/farmacologia , Estirenos/farmacologia , Alicerces Teciduais/química , Células Cultivadas , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Feminino , Humanos , Polímeros/química , Células Estromais/citologia , Células Estromais/efeitos dos fármacos , Estirenos/química , Alicerces Teciduais/efeitos adversos
14.
Macromol Rapid Commun ; 39(19): e1700831, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29450934

RESUMO

Since their discovery in 1993, interest in various aspects of cyclic peptides (CPs) has expanded rapidly. Of particular note is their potential to form artificial ion channels in lipid membranes, an attractive characteristic in supramolecular chemistry and biological research. The design and synthesis of cyclic peptide-polymer conjugates (CPPCs) that can self-assemble within lipid bilayers into nanotubes, mimicking naturally occurring membrane channels and pores, has been reported. However, methods that allow direct detection of the transport process with high levels of certainty are still lacking. This work focuses on the development of a simple but reliable approach to verify and quantify proton transport across a bilayer membrane. Giant unilamellar vesicles (GUVs) are created via the electroformation method and CPPCs are incorporated in GUV membranes at varying concentrations (0-10%). Confocal fluorescence microscopy is used to demonstrate full inclusion of fluorescein-labeled CPPCs in the GUV membranes. The pH-sensitive dye carboxyfluorescein is encapsulated within the water pool of the GUVs and used as an indicator of proton transport. This assay is versatile and can be exploited on other existing proton transporter systems, providing a consistent tool to compare their performances. It should also aid the development of novel antineoplastics and drug delivery systems.


Assuntos
Canais Iônicos/química , Nanotubos/química , Peptídeos Cíclicos/química , Prótons , Lipossomas Unilamelares/química , Transporte de Íons , Microscopia de Fluorescência
15.
Biomacromolecules ; 17(8): 2672-9, 2016 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-27434596

RESUMO

Synthetic polymer nanoparticles that can be tailored through multivalent ligand display on the surface, while at the same time allowing encapsulation of desired bioactive molecules, are especially useful in providing a versatile and robust platform in the design of specific delivery vehicles for various purposes. Glycosylated nanoparticles (glyco-NPs) of a poly(n-butyl acrylate) (pBA) core and poly(N-2-(ß-d-glucosyloxy)ethyl acrylamide) (p(NßGlcEAM)) or poly(N-2-(ß-D-galactosyloxy)ethyl acrylamide) (p(NßGalEAM)) corona were prepared via nanoprecipitation in aqueous solutions of preformed amphiphilic glycopolymers. Well-defined block copolymers of (poly(pentafluorophenyl acrylate) (pPFPA) and pBA were first prepared by RAFT polymerization followed by postpolymerization functionalization with aminoethyl glycosides to yield p(NßGlcEAM-b-BA) and p(NßGalEAM-b-BA), which were then used to form glyco-NPs (glucosylated and galactosylated NPs, Glc-NPs and Gal-NPs, respectively). The glyco-NPs were characterized by dynamic light scattering (DLS) and TEM. Encapsulation and release of ampicillin, leading to nanoparticles that we have termed "glyconanobiotics", were studied. The ampicillin-loaded glyco-NPs were found to induce aggregation of Staphylococcus aureus and Escherichia coli and resulted in antibacterial activity approaching that of ampicillin itself. This glyconanobiotics strategy represents a potential new approach for the delivery of antibiotics close to the surface of bacteria by promoting bacterial aggregation. Defined release in the proximity of the bacterial envelope may thus enhance antibacterial efficiency and potentially reduce the quantities of agent required for potency.


Assuntos
Anti-Infecciosos/administração & dosagem , Sistemas de Liberação de Medicamentos , Escherichia coli/efeitos dos fármacos , Nanopartículas/química , Polímeros/química , Staphylococcus aureus/efeitos dos fármacos , Glicosilação
16.
Biomacromolecules ; 17(8): 2719-25, 2016 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-27403588

RESUMO

PEGylation, the covalent modification of proteins with polyethylene glycol, is an abundantly used technique to improve the pharmacokinetics of therapeutic proteins. The drawback with this methodology is that the covalently attached PEG can impede the biological activity (e.g., reduced receptor-binding capacity). Protein therapeutics with "disposable" PEG modifiers have potential advantages over the current technology. Here, we show that a protein-polymer "Medusa complex" is formed by the combination of a hexavalent lectin with a glycopolymer. Using NMR spectroscopy, small-angle X-ray scattering (SAXS), size exclusion chromatography, and native gel electrophoresis it was demonstrated that the fucose-binding lectin RSL and a fucose-capped polyethylene glycol (Fuc-PEG) form a multimeric assembly. All of the experimental methods provided evidence of noncovalent PEGylation with a concomitant increase in molecular mass and hydrodynamic radius. The affinity of the protein-polymer complex was determined by ITC and competition experiments to be in the micromolar range, suggesting that such systems have potential biomedical applications.


Assuntos
Lectinas/química , Polietilenoglicóis/química , Cromatografia em Gel , Espectroscopia de Ressonância Magnética , Espalhamento a Baixo Ângulo , Difração de Raios X
17.
J Enzyme Inhib Med Chem ; 31(6): 1694-7, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26899668

RESUMO

The synthesis of a series of benzimidazole-N-benzylpropan-1-amines and adenine-N-benzylpropan-1-amines is described. Subsequent evaluation against two strains of the anaerobic bacterium Clostridium difficile was performed with three amine derivatives displaying MIC values of 16 µg/mL. Molecular docking studies of the described amines determined that the amines interact within two active site pockets of C. difficile methionyl tRNA synthetase with methoxy substituents in the benzyl ring and an adenine biaryl moiety resulting in optimal binding interactions.


Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Clostridioides difficile/efeitos dos fármacos , Metionina tRNA Ligase/efeitos dos fármacos , Propano/análogos & derivados , Antibacterianos/química , Desenho de Fármacos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Propano/farmacologia
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