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PURPOSE: Health service use is most intensive in the final year of a person's life, with 80% of this expenditure occurring in hospital. Close involvement of primary care services has been promoted to enhance quality end-of-life care that is appropriate to the needs of patients. However, the relationship between primary care involvement and patients' use of hospital care is not well described. This study aims to examine primary care use in the last year of life for cancer patients and its relationship to hospital usage. METHODS: Retrospective cohort study in Victoria, Australia, using linked routine care data from primary care, hospital and death certificates. Patients were included who died related to cancer between 2008 and 2017. RESULTS: A total of 758 patients were included, of whom 88% (n = 667) visited primary care during the last 6 months (median 9.1 consultations). In the last month of life, 45% of patients were prescribed opioids, and 3% had imaging requested. Patients who received home visits (13%) or anticipatory medications (15%) had less than half the median bed days in the last 3 months (4 vs 9 days, p < 0.001, 5 vs 10 days, p = 0.001) and 1 month of life (0 vs 2 days, p = 0.002, 0 vs 3 days, p < 0.001), and reduced emergency department presentations (32% vs 46%, p = 0.006, 31% vs 47% p < 0.001) in the final month. CONCLUSION: This study identifies two important primary care processes-home visits and anticipatory medication-associated with reduced hospital usage and intervention at the end of life.
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Morte , Neoplasias , Humanos , Estudos Retrospectivos , Hospitais , Neoplasias/terapia , Vitória , Atenção Primária à SaúdeRESUMO
Immunization is an effective and safest way to prevent vaccine-preventable diseases and thereby reduce morbidity and mortality in children. Injections given for immunization are the most usual ground in order to abstract agony or pain, which is the fifth vital sign leading to long-term physically and psychologically detrimental effects. A basic experimental (control group only for post-test) design using the technique of probability of simple random sampling in order to obtain sample size 105 was conducted in an Immunization Clinic at a selected PHC, Tamil Nadu, India. Ice cube was applied for about 30 seconds that is enfolded with gauze and then injected intramuscularly to administer the IM vaccine. In order to assess the pain level, an observation checklist based on Children's Hospital Eastern Ontario pain scale and Wong Baker's Faces pain scale was used. The study results manifest the higher statistical difference in the level of children's pain between the control groups and the experimental groups at a significance level of p<0.001. In order to reduce the pain level, the application of ice at LI-4 acupoint is effective. The children who are being vaccinated pass through stressful events through the application of an intramuscular injection. The findings revealed that ice application at LI-4 acupoint was very effective in pain reduction, which is a simple, safe, non-invasive, very efficient, easy-to-administer intervention and cost-effective without side effects than any other pharmacological pain intervention.
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Pontos de Acupuntura , Dor , Criança , Humanos , Injeções Intramusculares/efeitos adversos , Índia , Dor/prevenção & controle , VacinaçãoRESUMO
Using electrospun fibers to deliver therapeutic agents has gained significant attention in various applications including cancer treatment and tissue regeneration. However, the effect of fluid flow and uptake by cells on the concentration profile is not well understood. In this study, we evaluated the release of lipophilic resveratrol from poly(ε-caprolactone) (PCL)-gelatin (GT) electrospun fibers experimentally and by using computational fluid dynamics (CFD). Resveratrol containing PCL-GT electrospun fibers were formed and used in a custom-built tubular bioreactor, to assess flow effect on concentration profile over 5 days. CFD model was developed to simulate release in both static cultures and under fluid flow conditions. Resveratrol stability in the culture medium and uptake by human umbilical vein endothelial cells and K562 cells over 3 days were used in the model. The concentration profile as a function of time was simulated and validated by experiments. The effects of inlet velocity, cellular uptake rate, bioreactor's length, and surrounding tissue porosity were assessed. The release profile was mainly affected by cellular uptake and the presence of porous media. The model suggests that the perfusion velocity might not have a significant effect relative to the cellular uptake rate and porosity of the surrounding tissue.
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Células Endoteliais , Poliésteres , Gelatina , Humanos , Porosidade , Resveratrol , Engenharia TecidualRESUMO
Introduction: Combination therapy has been explored for its potential to reduce or eliminate multidrug resistance in treating different types of cancer including leukemia. Nutraceutical, small molecular drugs, and small interfering ribonucleic acid (siRNA) are some of the effective drugs. In order to avoid off-site targeting, reduce the dosage required, and increase the half-life of the drug in the circulation system, drug delivery vehicles, such as nanoparticles and microfibers have been explored.Areas covered: This review summarizes various therapies utilized in treating leukemia based on their effectiveness in inducing protein inhibition and/or apoptosis. In particular, treatment effectiveness using combination therapy using various devices is addressed. Recently explored drug delivery methods are reviewed, providing examples and their applications in cancer treatment. The drug listing, delivery systems classifications, along with the general modeling approach in this review, provide, to a full extent, a basis for cancer drug delivery future studies.Expert opinion: The reviewer's opinion tackles the potential of using a multi-delivery system to deliver multiple drugs, providing better control upon drug release and targeting. Both local and systemic delivery are considered and explored for their potential targets. Researchers are advised to pre-consider all aspects associated with their desired delivery method.
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Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Sistemas de Liberação de Medicamentos , Neoplasias/tratamento farmacológico , Antineoplásicos/química , Combinação de Medicamentos , Liberação Controlada de Fármacos , Humanos , Modelos BiológicosRESUMO
AIM: To compare the characteristics of and outcomes for people with malignancies with and without a co-diagnosis of diabetes. METHODS: Emergency department and hospital discharge data from a single centre for the period between 1 January 2015 and 31 December 2017 were used to identify people with a diagnosis of a malignancy and diabetes. Multivariate Cox regression models were used to estimate the effect of diabetes on all-cause mortality. A truncated negative binomial regression model was used to assess the impact of diabetes on length of hospital inpatient stay. Prentice-Williams-Peterson total time models were used to assess the effect of diabetes on number of emergency department re-presentations and inpatient re-admissions. RESULTS: Of 7004 people identified with malignancies, 1195 (17.1%) were also diagnosed with diabetes. A diagnosis of diabetes was associated with a greater number of inpatient re-admissions [adjusted hazard ratio 1.13 (95% CI 1.03, 1.24)], a greater number of emergency department re-presentations [adjusted hazard ratio 1.13 (95% CI 1.05, 1.22)] and longer length of stay [adjusted incidence rate ratio 1.14 (95% CI 1.04, 1.25)]. A co-diagnosis of diabetes was also associated with a 48% increased risk of all-cause mortality [adjusted hazard ratio 1.48 (95% CI 1.22-1.76)]. CONCLUSIONS: People with malignancies and diabetes had significantly more emergency department presentations, more inpatient admissions, longer length of hospital stay and higher rates of all-cause mortality compared to people with a malignancy without diabetes.
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Diabetes Mellitus Tipo 2/epidemiologia , Serviço Hospitalar de Emergência/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Tempo de Internação/estatística & dados numéricos , Mortalidade , Neoplasias/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Estudos de Casos e Controles , Causas de Morte , Estudos de Coortes , Comorbidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos RetrospectivosRESUMO
In this study, we evaluated a novel combination of drug delivery devices composed of holo-transferrin conjugated liposomes for siRNA (36â¯nM) delivery, and electrospun polycaprolactone (PCL)-gelatin (GT) microfibers for resveratrol (40⯵M) release. Single- and co-cultures of cancerous K562 cells and human umbilical vein endothelial cells (HUVECs) were used to test the efficacy and targeting over eight days. BCR-ABL siRNA-encapsulated (36â¯nM) holo-transferrin-conjugated PEG-liposomes were characterized using dynamic light scattering, and transmission electron microscopy. RT-qPCR was performed to assess the silencing BCR-ABL gene. Two treatment protocols were explored: i) simultaneous administration ii) delayed liposomes addition by three days based on resveratrol release profile. Formed liposomes were 123 (±6.65)â¯nm in diameter, holo-transferrin conjugation efficiency was 85.9 (±7.30)%, and siRNA loading efficiency was 92.3 (±2.57)%. Sphingosine-1-phosphate (S1P) content was analyzed by ELISA. Targeted siRNA release in combination with resveratrol release was more potent and has long-term effects compared to bolus doses. Delayed addition of liposomes increased non-viability of K562 cells to 92.7 (±2.00)% and 94.32 (±1.70)%, in the absence and presence of HUVECs, respectively. HUVECs non-viability level was significantly lower. Using two different delivery devices approach has a broader impact on cancer treatment.
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Sistemas de Liberação de Medicamentos , Proteínas de Fusão bcr-abl/genética , Neoplasias/terapia , RNA Interferente Pequeno/administração & dosagem , Resveratrol/administração & dosagem , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Gelatina/administração & dosagem , Inativação Gênica , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Células K562 , Lipossomos , Neoplasias/genética , Poliésteres/administração & dosagemRESUMO
Based on the hypothesis that bioscaffold permeability is a major factor in determining the outcome of histologically complete and functional bladder regeneration, we evaluated regeneration processes of four-layer porcine small intestinal submucosa (SIS) construct; and compared results between rat bladders augmented with single-layer SIS bioscaffolds. Sprague-Dawley female rats were subjected to hemi-cystectomy followed by anastomosis of a patch of either single- or four-layer porcine SIS. Permeability was analyzed in situ using magnetic resonance imaging (MRI) at post-operative days 7 and 14. Bladder sections excised at days 7, 14, 28, and 56 post-operation Samples were assessed by H&E and Masson's trichrome stains. Urothelial differentiation was analyzed using cytokeratin AE1/AE3, and uroplakin III (UPIII). In addition, quantitative and qualitative evaluations of neutrophils, mast cells, eosinophils, and macrophages were performed using anti-myeloperoxidase, Alcian blue, Giemsa stain, and anti-CD68 staining methods, respectively. Four-layer SIS was consistently impermeable as evidenced by the absence of intravesical administered gadolinium with diethylenetriaminepentacetate (Gd-DTPA) contrast signal in peripheral regions of augmented bladders compared with single-layer SIS bioscaffold. Elevated and sustained eosinophil and neutrophil infiltrations were prominent in four-layered SIS-augmented bladders compared with single-layer SIS with comparable impermeability. Delayed but consistent urothelial regeneration and differentiation were observed in four-layer SIS-augmented bladders; and urothelial differentiation was observed at day 56 post-augmentation. In conclusion, four-layer SIS enacts an elevated inflammatory response along with extended urothelial regeneration. Four-layer SIS may activate a different but yet to be identified mechanism for inflammatory responses. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1960-1969, 2019.
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Imunomodulação , Mucosa Intestinal/química , Intestino Delgado/química , Regeneração , Alicerces Teciduais/química , Bexiga Urinária , Urotélio , Animais , Feminino , Ratos , Ratos Sprague-Dawley , Suínos , Bexiga Urinária/lesões , Bexiga Urinária/fisiologia , Urotélio/lesões , Urotélio/fisiologiaRESUMO
Recent advances in developing in vitro tissue models show that function of hepatocytes is altered in when cultured in 3D configuration and co-culturing with various non-parenchymal cells. However, tissue source for such non-parenchymal cells on viability and metabolic products of hepatocytes have not been explored. In this study, we evaluated the effect of 2D and 3D cultures either with HepaRG cells alone or in combination with liver sinusoidal endothelial cells (LSECs) and human umbilical vein ECs (HUVECs). For 3D cultures, we used chitosan-gelatin porous structures formed by freeze-drying. We cultured cells for 8 days before challenging with 1 mm acetaminophen (APAP) and assessed APAP, APAP-sulfate and APAP-glucuronide for 24 hours at 6-hour time intervals using high-performance liquid chromatography. We used multiple methods (phase contrast, confocal and scanning electron microscopy and histology via hematoxylin and eosin staining) to ensure cell distribution. We also measured total protein content and albumin secretion and viability. HUVEC 3D co-cultures showed the lowest HepaRG cell viability, while both 2D and 3D LSEC co-cultures had highest HepaRG cell viability. In addition, 3D cultures had significantly higher EC viability relative to 2D cultures. Further, HUVEC co-cultures showed reduced total protein content and albumin expression as early as day 4. However, urea production on a total protein content basis did not change. In addition, LSEC 3D co-cultures had the highest APAP conversion with reduced APAP-sulfate and APAP-glucuronide formation. CYP3A4 was higher in co-culture with HUVEC for 2D and 3D cultures. In conclusion, HepaRG cells with EC co-cultures demonstrated sensitivity to the EC line used.
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Acetaminofen/metabolismo , Células Endoteliais/fisiologia , Hepatócitos/metabolismo , Sobrevivência Celular , Células Cultivadas , Técnicas de Cocultura , Citocromo P-450 CYP3A/metabolismo , Células Endoteliais da Veia Umbilical Humana/fisiologia , Humanos , Proteínas/análiseRESUMO
INTRODUCTION: The growing burden of chronic diseases means some governments have been providing financial incentives for multidisciplinary care and self-management support delivered within primary care. Currently, population-based evaluations of the effectiveness of these policies are lacking. AIM: To outline the methodological approach for our study that is designed to evaluate the effectiveness (including cost) of primary care policies for chronic diseases in Australia using stroke as a case study. METHODS: Person-level linkages will be undertaken between registrants from the Australian Stroke Clinical Registry (AuSCR) and (i) Government-held Medicare Australia claims data, to identify receipt or not of chronic disease management and care coordination primary care items; (ii) state government-held hospital data, to define outcomes; and (iii) government-held pharmaceutical and aged care claims data, to define covariates. N=1500 randomly selected AuSCR registrants will be sent surveys to obtain patient experience information. In Australia, unique identifiers are unavailable. Therefore, personal-identifiers will be submitted to government data linkage units. Researchers will merge the de-identified datasets for analysis using a project identifier. An economic evaluation will also be undertaken. ANALYSIS: The index event will be the first stroke recorded in the AuSCR. Multivariable competing risks Poisson regression for multiple events, adjusted by a propensity score, will be used to test for differences in the rates of hospital presentations and medication adherence for different care (policy) types. Our estimated sample size of 25,000 patients will provide 80% estimated power (É>0.05) to detect a 6-8% difference in rates. The incremental costs per Quality-adjusted life years gained of community-based care following the acute event will be estimated from a health sector perspective. CONCLUSION: Completion of this study will provide a novel and comprehensive evaluation of the effectiveness and cost-effectiveness of Australian primary care policies. Its success will enable us to highlight the value of data-linkage for this type of research.
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Micropillar patterns were fabricated and used to study cell adhesion, morphology, and function. Micropillars were produced in poly(2-hydroxyethyl methacrylate (HEMA)/N,N-(dimethylaminoethyl)methacrylate (DMAEMA)/tetraethylene glycol dimethacrylate (TEGDMA)) hydrogels using soft lithography, had dimensions of 1 µm diameter, and were either 2.05 or 4.91 µm tall. The patterned hydrogel substrates increased adhesion and induced the formation of cellular aggregates. Digital micrographs were used to quantify aggregate size and number. Differentiation of hMSCs toward adipocytes and chondrocytes was performed using the respective complete culture and differentiation medium for 2 weeks. Cells were stained for Oil red O, Alcian blue, and Type II collagen. Hydrogel substrates supported the differentiation of hMSCs to adipocytes and chondrocytes. The taller micropillar patterns supported the attachment and growth of larger aggregates and were more amenable to aid chondrogenic differentiation.
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As an emerging sterilization technology, cold atmospheric plasma offers a dry, non-thermal, rapid process that is minimally damaging to a majority of substrates. However, the mechanisms by which plasma interacts with living cells are poorly understood and the plasma generation apparatuses are complex and resource-intensive. In this study, the roles of reactive oxygen species (ROS), nitric oxide (NO), and charged particles (ions) produced by surface dielectric barrier discharge (SDBD) plasma on prokaryotic (Listeria monocytogenes (Gram-positive)) and eukaryotic (human umbilical vein endothelial cells (HUVEC)) cellular function were evaluated. HUVEC and bacterial oxidative stress responses, the accumulation of nitrite in aqueous media, air ion density, and bacterial inactivation at various distances from SDBD actuators were measured. SDBD actuator designs were also varied in terms of electrode number and length to evaluate the cellular effects of plasma volume and power distribution. NO and ions were found to contribute minimally to the observed cellular effects, whereas ROS were found to cause rapid bacterial inactivation, induce eukaryotic and prokaryotic oxidative stress, and result in rapid oxidation of bovine muscle tissue. The results of this study underscore the dominance of ROS as the major plasma generated species responsible for cellular effects, with ions and RNS having a secondary, complimentary role.
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Gases em Plasma/química , Células Endoteliais da Veia Umbilical Humana , Humanos , Listeria monocytogenes , Óxido Nítrico/química , Nitritos/química , Estresse Oxidativo , Espécies Reativas de OxigênioRESUMO
In this study, we evaluated the possibility of i) local release of resveratrol from poly(ε-caprolactone) (PCL) and gelatin (GT) electrospun fibers and ii) combining (i) with siRNA designed to downregulate BCR-ABL pathway on K562 cancer cells. Initially, K562 cell culture experiments were performed using various bolus doses of resveratrol in combination with siRNA for 3â¯days using a factorial design of experiments approach. Resveratrol content was analyzed using HPLC and cell viability was assessed using Annexin V (Non-viable), and Propidium Iodide (PI) (Necrotic) based flow cytometry. Coaxial electrospun fibers with resveratrol were made using 1:1 PCL-GT blends in different configurations: single fibers and coaxial fibers with same polymer blends, or with PCL inner core. Loading efficiency and release profile over five days were analyzed. Based on release profile, K562 cell viability with fibers was analyzed over eight days. Dose dependent cell death was observed with bolus resveratrol and siRNA in the culture. However, resveratrol content depleted significantly when added directly to solution. The combination therapy was additive in solution. SEM analysis showed no phase separation of components and resveratrol loading efficiency varied from 77% to 88% in different configurations; 95% of resveratrol was released by day five. Permeability of resveratrol showed no significant dependency on fiber configuration. After 8â¯days, non-viable cell percentages with controlled release were similar to that at three-day bolus dose of resveratrol. However, siRNA interacted with the fibers, resulting in reduced effect on cells. Loading resveratrol into electrospun fibers provides a localized delivery at therapeutic level, and increased resveratrol's apoptotic effect. Using single fibers is sufficient for controlled release.
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Portadores de Fármacos , Leucemia/tratamento farmacológico , Nanofibras , RNA Interferente Pequeno/farmacologia , Resveratrol/farmacologia , Liberação Controlada de Fármacos , Gelatina/química , Humanos , Células K562 , Poliésteres/químicaRESUMO
Augmentation enterocystoplasty remains the gold standard surgical bladder reconstruction procedure to increase the capacity and compliance of dysfunctional bladders. Since the use of the patient's intestine has severe risks of complications, alternative biodegradable matrices have been explored. Porcine small intestinal submucosa (SIS) has gained immense interests in bladder reconstruction due to its favorable properties. However, trials have shown inconsistent regeneration with SIS, attributed to the heterogeneity in microstructures and mechanical properties. We hypothesize that uneven SIS permeability to urine is a factor responsible for the inconsistency. We measured permeability to urine in situ using a contrast enhanced-magnetic resonance imaging (MRI), and evaluated urothelium regeneration using immunohistochemical staining of urothelial cell markers in SIS-augmented rat bladders. Results showed significant differences in permeability among SIS-augmented rat bladders. Commercial SIS scaffolds were then categorized into nonleaky and leaky groups based on MRI results. Hematoxylin and eosin staining showed higher numbers of inflammatory cells in leaky SIS on day 14 relative to nonleaky SIS. In addition, trichrome staining showed major changes in the distribution of collagen on day 28 between SIS-augmented bladder groups. Furthermore, expressions of urothelium-associated markers (cytokeratins AE1/AE3, claudin 4, and uroplakin III) were completed in bladders augmented with nonleaky SIS, whereas limited urothelial differentiation was noticed in leaky SIS-augmented bladders at post-augmentative day 14. These results show that scaffold permeability to urine may be responsible for variations in regenerative capacity of porcine SIS. Applications of MRI technique will be helpful to understand a relationship between biomaterial property and regenerative capacity. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1778-1787, 2018.
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Materiais Biocompatíveis , Mucosa Intestinal/química , Procedimentos de Cirurgia Plástica , Regeneração , Bexiga Urinária , Urotélio , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Diferenciação Celular/efeitos dos fármacos , Feminino , Imageamento por Ressonância Magnética , Permeabilidade , Ratos , Ratos Sprague-Dawley , Suínos , Bexiga Urinária/lesões , Bexiga Urinária/fisiologia , Bexiga Urinária/cirurgia , Urotélio/lesões , Urotélio/fisiologia , Urotélio/cirurgiaRESUMO
The primary bottleneck in bioprinting cell-laden structures with carefully controlled spatial relation is a lack of biocompatible inks and printing conditions. In this regard, we explored using thermogelling chitosan-gelatin (CG) hydrogel as a novel bioprinting ink; CG hydrogels are unique in that it undergoes a spontaneous phase change at physiological temperature, and does not need post-processing. In addition, we used a low cost (<$800) compact 3D printer, and modified with a new extruder to print using disposable syringes and hypodermic needles. We investigated (i) the effect of concentration of CG on gelation characteristics, (ii) solution preparation steps (centrifugation, mixing, and degassing) on printability and fiber formation, (iii) the print bed temperature profiles via IR imaging and grid-based assessment using thermocouples, (iv) the effect of feed rate (10-480 cm min-1), flow rate (15-60 µl min-1) and needle height (70-280 µm) on fiber size and characteristics, and (v) the distribution of neuroblastoma cells in printed fibers, and the viability after five days in culture. We used agarose gel to create uniform print surfaces to maintain a constant gap with the needle tip. These results showed that degassing the solution, and precooling the solution was necessary for obtaining continuous fibers. Fiber size decreased from 760, to 243 µm as the feed rate increased from 10 to 100 cm min-1. Bed temperature played the greatest role in fiber size, followed by feed rate. Increased needle height initially decreased fiber size but then increased showing an optimum. Cells were well distributed within the fibers and exhibited excellent viability and no contamination after 5 d. Overall we printed 3D, sterile, cell-laden structures with an inexpensive bioprinter and a novel ink, without post-processing. The bioprinter described here and the novel CG hydrogels have significant potential as an ink for bioprinitng various cell-laden structures.
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Bioimpressão , Quitosana/química , Gelatina/química , Hidrogéis/química , Impressão Tridimensional/instrumentação , Animais , Linhagem Celular Tumoral , Forma Celular , Sobrevivência Celular , Humanos , Reologia , Soluções , Sus scrofa , TemperaturaRESUMO
Recent advances in electrospinning allow the formation of multiple layers of micro and nanosize fibers to regulate drug/therapeutic agent release. Although there has been significant progress in fiber formation techniques and drug loading, fundamental models providing insights into controlling individual permeabilities is lacking. In this regard, we first explored forming coaxial hybrid fibers from hydrophobic poly(ε-caprolactone) (PCL) and hydrophilic gelatin (GT) in three different configurations, and the release of hydrophilic doxycycline (Dox) at 37°C over five days. Triaxial fibers were also formed with a GT layer between PCL/GT layers. Fibers were analyzed for fiber thickness, matrix porosity and thickness, surface morphologies, internal structures, stability in hydrated condition, viability and attachment of human adipocyte stem cells (hASC). Formed fibers were 10-30µm in diameter. hASC were viable, and showed attachment. Various release profiles were obtained from these fibers based on the combination of the core and shell polymers over five days. Using fiber characteristics and release profiles from each configuration, we obtained the overall permeability using Fick's first law and then individual layer permeability using resistance in series model. Calculated overall permeability showed dependency on fiber thickness and partition coefficient of the drug in the region where it was loaded. Our modeling approach helps in optimizing the electrospinning process, drug loading, and polymer solution configuration in regulating controlled release of a drug.
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Poliésteres/química , Doxiciclina , Gelatina , Humanos , PermeabilidadeRESUMO
Electrospun fibers have seen an insurgence in biomedical applications due to their unique characteristics. Coaxial and triaxial electrospinning techniques have added new impetus via fabrication of multilayered nano and micro-size fibers. These techniques offer the possibility of forming fibers with features such as blending, reinforced core, porous and hollow structure. The unique fabrication process can be used to tailor the mechanical properties, biological properties and release of various factors, which can potentially be useful in various controlled drug delivery applications. Harvesting these advantages, various polymers and their combinations have been explored in a number of drug delivery and tissue regeneration applications. New advances have shown the requirement of drug-polymer compatibility in addition to drug-solvent compatibility. We summarize recent findings using both hydrophilic and hydrophobic (or lipophilic) drugs in hydrophobic or hydrophilic polymers on release behavior. We also describe the fundamental forces involved during the electrospinning process providing insight to the factors to be considered to form fibers. Also, various modeling efforts on the drug release profiles are summarized. In addition new developments in the immune response to the electrospun fibers, and advances in scale-up issues needed for industrial size manufacturing.
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Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Interações Hidrofóbicas e Hidrofílicas , Microscopia EletrônicaRESUMO
This study evaluated a novel approach to decellularizing porcine adipose tissue while preserving its 3-D architecture. An ethanol-water mixture was used as a solvent to remove lipids and the number of freeze-thaw cycles (1-7), ethanol concentration, and tissue thickness were tested. Trypsin incubation time (1-3 h) and xylene immersion time were investigated separately. Processed sample microarchitecture was analyzed via scanning electron microscope, cellular content was analyzed via hematoxylin and eosin (H&E) staining, and DNA content was analyzed using gel electrophoresis. Tensile testing and five-stage incremental stress-relaxation testing was performed in phosphate-buffered saline at 37°C. Human neuroblasts were seeded and evaluated for infiltration and attachment over 8 days. Four cycles of freeze-thaw in 50% ethanol-water mixture removed one-third of the lipids. Microarchitecture showed the presence of pores, capillary channels, and lack of sidedness; H&E micrographs confirmed unaltered morphology and absence of cells. Incubation for 1.5 h in trypsin removed 99.5% DNA from delipidized samples. An average of 40% rehydration swelling, an elastic modulus of 324(±141) kPa, and an ultimate tensile strength of 87.4(±23.1) kPa were observed. The matrix exhibited strain hardening behavior similar to small intestinal submucosa. Cells successfully infiltrated and spread in the decellularized scaffold. Removal of lipids significantly reduced incubation in trypsin EDTA. In summary, the acellular matrix shows significant potential as a new template for tissue regeneration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 3127-3136, 2016.
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Tecido Adiposo/química , Matriz Extracelular/química , Neurônios/citologia , Alicerces Teciduais/química , Tecido Adiposo/citologia , Animais , Linhagem Celular , Proliferação de Células , DNA/isolamento & purificação , Matriz Extracelular/ultraestrutura , Congelamento , Humanos , Lipídeos/isolamento & purificação , Sonicação , Suínos , Resistência à Tração , Engenharia Tecidual , Xilenos/químicaRESUMO
We sought to investigate the frequency of mutations in epidermal growth factor receptor (EGFR) and Kirsten-RAS (KRAS) by each pathological subtype for patients with resected pulmonary adenocarcinoma as defined by the IASLC/ATS/ERS classification. Histological examination determined the predominant subtype according to the IASLC/ATS/ERS classification. EGFR and KRAS mutations were determined by high-resolution melting and Sanger sequencing. Clinical data were collected from medical records and clinicians. The 178 consecutive patients consisted of 48% males, median age 68 years (range 20-87) and smoking history 78%. The tumour stage was I in 62%, II in 18% and III in 20%. The mutation rates were: EGFR 30%; KRAS 28%. The rate of EGFR mutations in the acinar predominant reference group (n=76), was 37%. The solid predominant subtype showed significantly fewer EGFR mutations [3/33 (9%), odds ratio 0.17 (0.05-0.61), p=0.007]. No differences in mutation rate were observed in other subtypes. No association was found between KRAS mutations and predominant histological subtype. Advanced stage and solid predominant subtype were negative prognostic factors. EGFR mutations can be present in adenocarcinoma of any predominant subtype, however rarely in solid predominant tumours. No association was found between KRAS mutation and the predominant histological subtype.
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Adenocarcinoma/classificação , Adenocarcinoma/genética , Receptores ErbB/genética , Neoplasias Pulmonares/classificação , Neoplasias Pulmonares/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Adenocarcinoma de Pulmão , Adulto , Idoso , Idoso de 80 Anos ou mais , Povo Asiático/genética , Austrália , Estudos de Coortes , Feminino , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Mutação , Estadiamento de Neoplasias , Sociedades Médicas , Análise de Sobrevida , População Branca/genética , Adulto JovemRESUMO
Although local cell delivery is an option to repair tissues, particularly using chitosan-based hydrogels, significant attrition of injected cells prior to engraftment has been a problem. To address this problem, we explored the possibility of stabilizing the chitosan-gelatin (CG) injectable hydrogels using (1) controlled release of doxycycline (DOX) to prevent premature degradation due to increased gelatinase activity (MMP-2 and MMP-9), and (2) transglutaminase (TG) to in situ cross-link gelatin to improve the mechanical stability. We prepared DOX-loaded PLGA nanoparticles, loaded into the CG hydrogels, measured DOX release for 5 days, and modeled using a single-compartmental assumption. Next, we assessed the influence of TG and DOX on hydrogel compression properties by incubating hydrogels for 7 days in PBS. We evaluated the effect of these changes on retention of fibroblasts and alterations in MMP-2/MMP-9 activity by seeding 500,000 fibroblasts for 5 days. These results showed that 90 % of DOX released from cross-linked CG hydrogels after 4 days, unlike CG hydrogels where 90 % of DOX was released within the first day. Addition of TG enhanced the CG hydrogel stability significantly. More than 60 % of seeded fibroblasts were recovered from the CG-TG hydrogels at day 5, unlike 40 % recovered from CG-hydrogels. Inhibition of MMP-2/MMP-9 were observed. In summary, controlled release of DOX from CG hydrogels cross-linked with TG shows a significant potential as a carrier for cell delivery.