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1.
Ther Deliv ; 15(9): 653-666, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39225262

RESUMEN

Aim: In this study, we aimed to prepare enteric encapsulated spheroids containing inclusion complex using quality by design approach.Methods: A Box-Behnken design was employed to determine effects of variables on selected responses. Risk assessment was conducted using Ishikawa fishbone diagram. A model with a p-value was less than 0.5 for being a significant error of model was determined based on significance 'lack of fit' value. Spheroids were formulated using the extrusion spheronization technique and were characterized using analytical techniques.Results: In vitro release was performed in both acidic (pH 1.2) and simulated intestinal (pH 6.8) conditions. Permeability studies demonstrated tenfold enhancement compared with arteether. In vivo studies further validated increase of 51.8% oral bioavailability. Ex vivo studies revealed 3.4-fold enhancement in antimalarial activity compared with arteether.Conclusion: These findings highlight effectiveness of inclusion complexation technique as a viable approach to enhance solubility and bioavailability for drugs with low aqueous solubility.


[Box: see text].


Asunto(s)
Antimaláricos , Artemisininas , Disponibilidad Biológica , Solubilidad , Antimaláricos/farmacocinética , Antimaláricos/administración & dosificación , Antimaláricos/química , Animales , Artemisininas/administración & dosificación , Artemisininas/química , Artemisininas/farmacocinética , Artemisininas/farmacología , Permeabilidad , Administración Oral , Humanos , Química Farmacéutica/métodos , Masculino , Plasmodium falciparum/efectos de los fármacos , Absorción Intestinal , Concentración de Iones de Hidrógeno , Liberación de Fármacos
2.
Curr Drug Metab ; 25(1): 13-27, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38465436

RESUMEN

Warfarin is a popular anticoagulant with high global demand. However, studies have underlined serious safety issues when warfarin is consumed concomitantly with herbs or its formulations. This review aimed to highlight the mechanisms behind herb-warfarin interactions while laying special emphasis on its PKPD interactions and evidence on Herb-Warfarin Interaction (HWI) with regards to three different scenarios, such as when warfarin is consumed with herbs, taken as foods or prescribed as medicine, or when used in special situations. A targeted literature methodology involving different scientific databases was adopted for acquiring information on the subject of HWIs. Results of the present study revealed some of the fatal consequences of HWI, including post-operative bleeding, thrombosis, subarachnoid hemorrhage, and subdural hematomas occurring as a result of interactions between warfarin and herbs or commonly associated food products from Hypericum perforatum, Zingiber officinale, Vaccinium oxycoccos, Citrus paradisi, and Punica granatum. In terms of PK-PD parameters, herbs, such as Coptis chinensis Franch. and Phellodendron amurense Rupr., were found to compete with warfarin for binding with plasma proteins, leading to an increase in free warfarin levels in the bloodstream, resulting in its augmented antithrombic effect. Besides, HWIs were also found to decrease International Normalised Ratio (INR) levels following the consumption of Persea americana or avocado. Therefore, there is an urgent need for an up-to-date interaction database to educate patients and healthcare providers on these interactions, besides promoting the adoption of novel technologies, such as natural language processing, by healthcare professionals to guide them in making informed decisions to avoid HWIs.


Asunto(s)
Anticoagulantes , Interacciones de Hierba-Droga , Warfarina , Humanos , Warfarina/efectos adversos , Warfarina/farmacocinética , Anticoagulantes/efectos adversos , Anticoagulantes/farmacocinética , Animales
3.
Antioxidants (Basel) ; 12(10)2023 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-37891956

RESUMEN

Oxidative stress is a deteriorating condition that arises due to an imbalance between the reactive oxygen species and the antioxidant system or defense of the body. The key reasons for the development of such conditions are malfunctioning of various cell organelles, such as mitochondria, endoplasmic reticulum, and Golgi complex, as well as physical and mental disturbances. The nervous system has a relatively high utilization of oxygen, thus making it particularly vulnerable to oxidative stress, which eventually leads to neuronal atrophy and death. This advances the development of neuroinflammation and neurodegeneration-associated disorders such as Alzheimer's disease, Parkinson's disease, epilepsy, dementia, and other memory disorders. It is imperative to treat such conditions as early as possible before they worsen and progress to irreversible damage. Oxidative damage can be negated by two mechanisms: improving the cellular defense system or providing exogenous antioxidants. Natural antioxidants can normally handle such oxidative stress, but they have limited efficacy. The valuable features of nanoparticles and/or nanomaterials, in combination with antioxidant features, offer innovative nanotheranostic tools as potential therapeutic modalities. Hence, this review aims to represent novel therapeutic approaches like utilizing nanoparticles with antioxidant properties and nanotheranostics as delivery systems for potential therapeutic applications in various neuroinflammation- and neurodegeneration-associated disease conditions.

4.
Nanomedicine ; 54: 102711, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37813236

RESUMEN

For the past decades, gene editing demonstrated the potential to attenuate each of the root causes of genetic, infectious, immune, cancerous, and degenerative disorders. More recently, Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR-associated protein 9 (CRISPR-Cas9) editing proved effective for editing genomic, cancerous, or microbial DNA to limit disease onset or spread. However, the strategies to deliver CRISPR-Cas9 cargos and elicit protective immune responses requires safe delivery to disease targeted cells and tissues. While viral vector-based systems and viral particles demonstrate high efficiency and stable transgene expression, each are limited in their packaging capacities and secondary untoward immune responses. In contrast, the nonviral vector lipid nanoparticles were successfully used for as vaccine and therapeutic deliverables. Herein, we highlight each available gene delivery systems for treating and preventing a broad range of infectious, inflammatory, genetic, and degenerative diseases. STATEMENT OF SIGNIFICANCE: CRISPR-Cas9 gene editing for disease treatment and prevention is an emerging field that can change the outcome of many chronic debilitating disorders.


Asunto(s)
Sistemas CRISPR-Cas , Edición Génica , Sistemas CRISPR-Cas/genética , Proteína 9 Asociada a CRISPR/genética , Proteína 9 Asociada a CRISPR/metabolismo , Técnicas de Transferencia de Gen , Terapia Genética
5.
Artículo en Inglés | MEDLINE | ID: mdl-37855282

RESUMEN

BACKGROUND: Non-steroidal Anti-Inflammatory Drugs (NSAIDs) are among the drugs that are most regularly administered to manage inflammation and pain. Over-the-Counter (OTC) NSAIDs are widely accessible, particularly in developing countries like India. This casual approach to using NSAIDs may operate as a magnet for NSAID-related adverse drug reactions (ADRs) among patients. OBJECTIVES: As patients in India are less informed about the appropriate use of NSAIDs and consumption patttern, adverse drug reactions, and the importance of reporting ADRs, the current study's objective is to promote patient safety by using pharmacovigilance as a tool to educate patients. METHODS: A targeted literature methodology was utilized to gather the data pertaining to NSAIDs, their ADRs and their pharmacovigilance. Different scientific databases, such as Science Direct, PubMed, Wiley Online Library, Springer, and Google Scholar, along with authentic textbooks, were explored as reference literature. RESULTS: In general, NSAIDs consumption pattern depends upon the different age groups. Around 1.6 billion tablets of NSAIDs are consumed in India for ailments, such as headaches, arthritis, menstrual cramps, osteoarthritis, back pain, rheumatoid arthritis, gout, osteoporosis, tendinitis, cancer pain and chronic pain. Common ADRs of NSAIDs include nausea, vomiting, headache, gastritis, abdominal pain, and diarrhoea. Also, they can cause renal damage and cardiovascular problems if not consumed in a dose-dependent manner. However, Diclofenac and Ibuprofen have both been linked to depression and dementia. There have been reports of aplastic anaemia, agranulocytosis linked to phenylbutazone, Stevens-Johnson, and Lyell's syndrome linked to isoxicam and piroxicam, as well as the vulnerability of new-borns to Reye's syndrome after aspirin use. Lack of awareness, time constraints and unpredictability, poor training in ADRs identification, etc., are some of the reasons for the under-reporting of ADR of NSAIDs in India. CONCLUSION: In order to rationally prescribe NSAIDs, it is essential to be aware of probable ADR's and establish prescription guidelines. Prescribers' behaviour can be changed toward excellent prescribing practices by conducting routine prescription assessments dealing with NSAIDs and providing feedback. In the near future, it will be critical to strengthen ADR data management and expand the reach of pharmacovigilance programs, ADR monitoring centers, and healthcare professionals' especially pharmacists' training in rural locations.

6.
J Ethnopharmacol ; 309: 116383, 2023 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-36918049

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: The use of herbal medicines for prophylaxis, prevention, and treatment of various ailments is rising throughout the world because they are thought to be safer than allopathic treatments, which they are. However, several investigations have documented the toxicity and adverse drug reactions (ADR) of certain formulations and botanicals if not consumed wisely. AIM OF THE STUDY: The goal of the current study is to address herbal medication pharmacovigilance (PV) modeling and related considerations for improved patient safety. Also, focus is laid on the comprehensive and critical analysis of the current state of PV for herbal medications at the national and international levels. MATERIALS AND METHODS: Targeted review also known as focused literature review methodology was utilized for exploring the data from various scientific platforms such as Science Direct, Wiley Online Library, Springer, PubMed, Google Scholar using "pharmacovigilance, herbal medicine, traditional medicine, ADR, under reporting, herb toxicity, herb interactions" as keywords along with standard literature pertaining to herbal medicines that is published by the WHO and other international and national organizations etc. The botanical names mentioned in the present article were authenticated using World Flora Online database. RESULTS: The historical developments paving the way for PV in regulatory setup were also discussed, along with various criteria's for monitoring herbal medicine, ADR of herbs, phytoconstituents, and traditional medicines, herb-drug interactions, modes of reporting ADR, databases for reporting ADR's, provisions of PV in regulatory framework of different nations, challenges and way forward in PV are discussed in detail advocating a robust drug safety ecosystem for herbal medicines. CONCLUSION: Despite recent efforts to encourage the reporting of suspected ADRs linked to herbal medicines, such as expanding the programme and adding community pharmacists and other healthcare professionals as recognized reporters, the number of herbal ADR reports received by the regulatory bodies remains comparatively low. Since users often do not seek professional advice or report if they have side effects, under-reporting, is anticipated to be significant for herbal medications. There are inadequate quality control methods, poor regulatory oversight considering herbs used in food and botanicals, and unregulated distribution channels. In addition, botanical identity, traceability of herbs, ecological concerns, over-the-counter (OTC) herbal medicines, patient-physicians barriers requires special focus by the regulatory bodies for improved global safety of herbal medicines.


Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Plantas Medicinales , Humanos , Farmacovigilancia , Ecosistema , Plantas Medicinales/efectos adversos , Medicina de Hierbas , Extractos Vegetales
7.
Mini Rev Med Chem ; 23(9): 992-1032, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35546778

RESUMEN

Osteoarthritis (OA), a chronic degenerative musculoskeletal disorder, progressively increases with age. It is characterized by progressive loss of hyaline cartilage followed by subchondral bone remodeling and inflammaging. To counteract the inflammation, synovium releases various inflammatory and immune mediators along with metabolic intermediates, which further worsens the condition. However, even after recognizing the key molecular and cellular factors involved in the progression of OA, only disease-modifying therapies are available such as oral and topical NSAIDs, opioids, SNRIs, etc., providing symptomatic treatment and functional improvement instead of suppressing OA progression. Long-term use of these therapies leads to various life-threatening complications. Interestingly, mother nature has numerous medicinal plants containing active phytochemicals that can act on various targets involved in the development and progression of OA. Phytochemicals have been used for millennia in traditional medicine and are promising alternatives to conventional drugs with a lower rate of adverse events and efficiency frequently comparable to synthetic molecules. Nevertheless, their mechanism of action in many cases is elusive and uncertain. Even though many in vitro and in vivo studies show promising results, clinical evidence is scarce. Studies suggest that the presence of carbonyl group in the 2nd position, chloro in the 6th and an electron- withdrawing group at the 7th position exhibit enhanced COX-2 inhibition activity in OA. On the other hand, the presence of a double bond at the C2-C3 position of C ring in flavonoids plays an important role in Nrf2 activation. Moreover, with the advancements in the understanding of OA progression, SARs (structure-activity relationships) of phytochemicals and integration with nanotechnology have provided great opportunities for developing phytopharmaceuticals. Therefore, in the present review, we have discussed various promising phytomolecules, SAR as well as their nano-based delivery systems for the treatment of OA to motivate the future investigation of phytochemical-based drug therapy.


Asunto(s)
Nanotecnología , Osteoartritis , Humanos , Animales , Nanotecnología/métodos , Osteoartritis/tratamiento farmacológico , Plantas Medicinales , Fitoquímicos/farmacología , Fitoquímicos/uso terapéutico , Relación Estructura-Actividad , Productos Biológicos/farmacología , Productos Biológicos/uso terapéutico
8.
Curr Issues Mol Biol ; 44(10): 4584-4615, 2022 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-36286029

RESUMEN

Alzheimer's disease (AD) is a deadly brain degenerative disorder that leads to brain shrinkage and dementia. AD is manifested with hyperphosphorylated tau protein levels and amyloid beta (Aß) peptide buildup in the hippocampus and cortex regions of the brain. The nervous tissue of AD patients also contains fungal proteins and DNA which are linked to bacterial infections, suggesting that polymicrobial infections also occur in the brains of those with AD. Both immunohistochemistry and next-generation sequencing (NGS) techniques were employed to assess fungal and bacterial infections in the brain tissue of AD patients and non-AD controls, with the most prevalent fungus genera detected in AD patients being Alternaria, Botrytis, Candida, and Malassezia. Interestingly, Fusarium was the most common genus detected in the control group. Both AD patients and controls were also detectable for Proteobacteria, followed by Firmicutes, Actinobacteria, and Bacteroides for bacterial infection. At the family level, Burkholderiaceae and Staphylococcaceae exhibited higher levels in the brains of those with AD than the brains of the control group. Accordingly, there is thought to be a viscous cycle of uncontrolled neuroinflammation and neurodegeneration in the brain, caused by agents such as the herpes simplex virus type 1 (HSV1), Chlamydophilapneumonia, and Spirochetes, and the presence of apolipoprotein E4 (APOE4), which is associated with an increased proinflammatory response in the immune system. Systemic proinflammatory cytokines are produced by microorganisms such as Cytomegalovirus, Helicobacter pylori, and those related to periodontal infections. These can then cross the blood-brain barrier (BBB) and lead to the onset of dementia. Here, we reviewed the relationship between the etiology of AD and microorganisms (such as bacterial pathogens, Herpesviridae viruses, and periodontal pathogens) according to the evidence available to understand the pathogenesis of AD. These findings might guide a targeted anti-inflammatory therapeutic approach to AD.

9.
AAPS PharmSciTech ; 23(7): 253, 2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-36109467

RESUMEN

α, ß-Arteether (ART) antimalarial drug is used to treat chloroquine-resistant malaria and cerebral malaria. The drug's solubility in water is relatively low (17 µg/mL), and 40% of the drug degrades in the stomach, resulting in poor bioavailability. This article discusses the quality by design technique used for formulation development and optimization of nanostructured lipid carriers (NLCs). The ART-NLCs were made by solvent diffusion method. To develop solid NLCs, the NLCs were freeze-dried and encapsulated in enteric-coated capsule shells. The prepared NLCs showed particle size ranging between 156.8 ± 12 nm while zeta potential ranging between - 26.1 ± 0.22 mV. They also showed high encapsulation efficiency (> 85%) and an amorphous drug's lipid matrix state. Pharmacokinetic parameters of optimized formulation enhance oral bioavailability to 18.45%. These investigations demonstrated the superiority of NLCs for improvement of solubility as well as oral bioavailability of poorly water-soluble drugs.


Asunto(s)
Antimaláricos , Portadores de Fármacos , Administración Oral , Disponibilidad Biológica , Cloroquina , Lípidos , Solventes , Agua
10.
Nat Mater ; 20(5): 593-605, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33589798

RESUMEN

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread to nearly every corner of the globe, causing societal instability. The resultant coronavirus disease 2019 (COVID-19) leads to fever, sore throat, cough, chest and muscle pain, dyspnoea, confusion, anosmia, ageusia and headache. These can progress to life-threatening respiratory insufficiency, also affecting the heart, kidney, liver and nervous systems. The diagnosis of SARS-CoV-2 infection is often confused with that of influenza and seasonal upper respiratory tract viral infections. Due to available treatment strategies and required containments, rapid diagnosis is mandated. This Review brings clarity to the rapidly growing body of available and in-development diagnostic tests, including nanomaterial-based tools. It serves as a resource guide for scientists, physicians, students and the public at large.


Asunto(s)
Prueba de COVID-19/métodos , COVID-19/diagnóstico , SARS-CoV-2 , Anticuerpos Antivirales/sangre , Antígenos Virales/análisis , Encéfalo/diagnóstico por imagen , COVID-19/diagnóstico por imagen , COVID-19/virología , Prueba de Ácido Nucleico para COVID-19/métodos , Prueba Serológica para COVID-19/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Pulmón/diagnóstico por imagen , Metagenómica/métodos , Nanoestructuras , Nanotecnología , Pandemias , SARS-CoV-2/genética , SARS-CoV-2/inmunología , SARS-CoV-2/aislamiento & purificación , Carga Viral , Esparcimiento de Virus
11.
J Neuroimmune Pharmacol ; 16(2): 270-288, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33544324

RESUMEN

Extracellular vesicles (EVs) are the common designation for ectosomes, microparticles and microvesicles serving dominant roles in intercellular communication. Both viable and dying cells release EVs to the extracellular environment for transfer of cell, immune and infectious materials. Defined morphologically as lipid bi-layered structures EVs show molecular, biochemical, distribution, and entry mechanisms similar to viruses within cells and tissues. In recent years their functional capacities have been harnessed to deliver biomolecules and drugs and immunological agents to specific cells and organs of interest or disease. Interest in EVs as putative vaccines or drug delivery vehicles are substantial. The vesicles have properties of receptors nanoassembly on their surface. EVs can interact with specific immunocytes that include antigen presenting cells (dendritic cells and other mononuclear phagocytes) to elicit immune responses or affect tissue and cellular homeostasis or disease. Due to potential advantages like biocompatibility, biodegradation and efficient immune activation, EVs have gained attraction for the development of treatment or a vaccine system against the severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) infection. In this review efforts to use EVs to contain SARS CoV-2 and affect the current viral pandemic are discussed. An emphasis is made on mesenchymal stem cell derived EVs' as a vaccine candidate delivery system.


Asunto(s)
Tratamiento Farmacológico de COVID-19 , Sistemas de Liberación de Medicamentos/tendencias , Vesículas Extracelulares , SARS-CoV-2/efectos de los fármacos , Animales , Antivirales/administración & dosificación , Antivirales/metabolismo , COVID-19/inmunología , COVID-19/metabolismo , Sistemas de Liberación de Medicamentos/métodos , Vesículas Extracelulares/inmunología , Vesículas Extracelulares/metabolismo , Humanos , Inmunidad Celular/efectos de los fármacos , Inmunidad Celular/fisiología , Factores Inmunológicos/administración & dosificación , Factores Inmunológicos/metabolismo , SARS-CoV-2/inmunología , SARS-CoV-2/metabolismo
12.
J Neuroimmune Pharmacol ; 16(1): 12-37, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33403500

RESUMEN

The COVID-19 pandemic has affected more than 38 million people world-wide by person to person transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therapeutic and preventative strategies for SARS-CoV-2 remains a significant challenge. Within the past several months, effective treatment options have emerged and now include repurposed antivirals, corticosteroids and virus-specific antibodies. The latter has included convalescence plasma and monoclonal antibodies. Complete viral eradication will be achieved through an effective, safe and preventative vaccine. To now provide a comprehensive summary for each of the pharmacotherapeutics and preventative strategies being offered or soon to be developed for SARS-CoV-2.


Asunto(s)
Tratamiento Farmacológico de COVID-19 , Anticuerpos Antivirales/uso terapéutico , Antivirales/farmacología , COVID-19/prevención & control , COVID-19/transmisión , Vacunas contra la COVID-19 , Reposicionamiento de Medicamentos , Humanos
13.
Adv Drug Deliv Rev ; 171: 215-239, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33428995

RESUMEN

The SARS-CoV-2 global pandemic has seen rapid spread, disease morbidities and death associated with substantive social, economic and societal impacts. Treatments rely on re-purposed antivirals and immune modulatory agents focusing on attenuating the acute respiratory distress syndrome. No curative therapies exist. Vaccines remain the best hope for disease control and the principal global effort to end the pandemic. Herein, we summarize those developments with a focus on the role played by nanocarrier delivery.


Asunto(s)
Vacunas contra la COVID-19/administración & dosificación , COVID-19/prevención & control , Portadores de Fármacos/administración & dosificación , Nanocápsulas/administración & dosificación , SARS-CoV-2/efectos de los fármacos , Animales , COVID-19/inmunología , Vacunas contra la COVID-19/inmunología , Sistemas de Liberación de Medicamentos/métodos , Sistemas de Liberación de Medicamentos/tendencias , Humanos , SARS-CoV-2/inmunología , Vacunas Virales/administración & dosificación , Vacunas Virales/inmunología
14.
Biomed Opt Express ; 10(1): 322-337, 2019 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-30775103

RESUMEN

A method to register THz and visible images of cutaneous burn wounds and to calibrate THz image data is presented. Images of partial and full thickness burn wounds in 9 rats were collected over 435 mins. = 7.25 hours following burn induction. A two-step process was developed to reference the unknown structure of THz imaging contrast to the known structure and the features present in visible images of the injury. This process enabled the demarcation of a wound center for each THz image, independent of THz contrast. Threshold based segmentation enabled the automated identification of air (0% reflectivity), brass (100% reflectivity), and abdomen regions within the registered THz images. Pixel populations, defined by the segmentations, informed unsupervised image calibration and contrast warping for display. The registered images revealed that the largest variation in THz tissue reflectivity occurred superior to the contact region at ~0.13%/min. Conversely the contact region showed demonstrated an ~6.5-fold decrease at ~0.02%/min. Exploration of occlusion effects suggests that window contact may affect the measured edematous response.

15.
IEEE Trans Terahertz Sci Technol ; 8(1): 1-12, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29450106

RESUMEN

Reflection mode Terahertz (THz) imaging of corneal tissue water content (CTWC) is a proposed method for early, accurate detection and study of corneal diseases. Despite promising results from ex vivo and in vivo cornea studies, interpretation of the reflectivity data is confounded by the contact between corneal tissue and dielectric windows used to flatten the imaging field. Herein, we present an optical design for non-contact THz imaging of cornea. A beam scanning methodology performs angular, normal incidence sweeps of a focused beam over the corneal surface while keeping the source, detector, and patient stationary. A quasioptical analysis method is developed to analyze the theoretical resolution and imaging field intensity profile. These results are compared to the electric field distribution computed with a physical optics analysis code. Imaging experiments validate the optical theories behind the design and suggest that quasioptical methods are sufficient for designing of THz corneal imaging systems. Successful imaging operations support the feasibility of non-contact in vivo imaging. We believe that this optical system design will enable the first, clinically relevant, in vivo exploration of CTWC using THz technology.

16.
IEEE Trans Terahertz Sci Technol ; 8(1): 27-37, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29430335

RESUMEN

Terahertz (THz) imaging of corneal tissue water content (CTWC) is a proposed method for early, accurate detection and study of corneal diseases. Despite promising results from ex vivo and in vivo cornea studies, interpretation of the reflectivity data is confounded by the contact between corneal tissue and rigid dielectric window used to flatten the imaging field. This work develops a novel imaging system and image reconstruction methods specifically for nearly spherical targets such as human cornea. A prototype system was constructed using a 650 GHz multiplier source and Schottky diode detector. Resolution and imaging field strength measurement from characterization targets correlate well with those predicted by the quasioptical theory and physical optics analysis. Imaging experiments with corneal phantoms and ex vivo corneas demonstrate the hydration sensitivity of the imaging system and reliable measurement of CTWC. We present successful acquisition of non-contact THz images of in vivo human cornea, and discuss strategies for optimizing the imaging system design for clinical use.

17.
PLoS One ; 13(1): e0191919, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29373598

RESUMEN

Viscoelasticity of soft tissue is often related to pathology, and therefore, has become an important diagnostic indicator in the clinical assessment of suspect tissue. Surgeons, particularly within head and neck subsites, typically use palpation techniques for intra-operative tumor detection. This detection method, however, is highly subjective and often fails to detect small or deep abnormalities. Vibroacoustography (VA) and similar methods have previously been used to distinguish tissue with high-contrast, but a firm understanding of the main contrast mechanism has yet to be verified. The contributions of tissue mechanical properties in VA images have been difficult to verify given the limited literature on viscoelastic properties of various normal and diseased tissue. This paper aims to investigate viscoelasticity theory and present a detailed description of viscoelastic experimental results obtained in tissue-mimicking phantoms (TMPs) and ex vivo tissues to verify the main contrast mechanism in VA and similar imaging modalities. A spherical-tip micro-indentation technique was employed with the Hertzian model to acquire absolute, quantitative, point measurements of the elastic modulus (E), long term shear modulus (η), and time constant (τ) in homogeneous TMPs and ex vivo tissue in rat liver and porcine liver and gallbladder. Viscoelastic differences observed between porcine liver and gallbladder tissue suggest that imaging modalities which utilize the mechanical properties of tissue as a primary contrast mechanism can potentially be used to quantitatively differentiate between proximate organs in a clinical setting. These results may facilitate more accurate tissue modeling and add information not currently available to the field of systems characterization and biomedical research.


Asunto(s)
Elasticidad , Modelos Animales , Fantasmas de Imagen , Viscosidad , Animales , Masculino , Ratas Sprague-Dawley , Porcinos
18.
IEEE Trans Biomed Eng ; 64(11): 2682-2694, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28141514

RESUMEN

OBJECTIVE: In vivo visualization and quantification of edema, or 'tissue swelling' following injury, remains a clinical challenge. Herein, we investigate the ability of reflective terahertz (THz) imaging to track changes in tissue water content (TWC)-the direct indicator of edema-by comparison to depth-resolved magnetic resonance imaging (MRI) in a burn-induced model of edema. METHODS: A partial thickness and full thickness burns were induced in an in vivo rat model to elicit unique TWC perturbations corresponding to burn severity. Concomitant THz surface maps and MRI images of both burn models were acquired with a previously reported THz imaging system and T2-weighted MRI, respectively, over 270 min. Reflectivity was analyzed for the burn contact area in THz images, while proton density (i.e., mobile TWC) was analyzed for the same region at incrementally increasing tissue depths in companion, transverse MRI images. A normalized cross correlation of THz and depth-dependent MRI measurements was performed as a function of time in histologically verified burn wounds. RESULTS: For both burn types, strong positive correlations were evident between THz reflectivity and MRI data analyzed at greater tissue depths (>258 µm). MRI and THz results also revealed biphasic trends consistent with burn edema pathogenesis. CONCLUSION: This paper offers the first in vivo correlative assessment of mobile TWC-based contrast and the sensing depth of THz imaging. SIGNIFICANCE: The ability to implement THz imaging immediately following injury, combined with TWC sensing capabilities that compare to MRI, further support THz sensing as an emerging tool to track fluid in tissue.


Asunto(s)
Quemaduras/diagnóstico por imagen , Edema/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Imágen por Terahertz/métodos , Animales , Modelos Animales de Enfermedad , Interpretación de Imagen Asistida por Computador , Masculino , Ratas , Ratas Sprague-Dawley , Procesamiento de Señales Asistido por Computador
19.
Biomed Opt Express ; 8(1): 460-474, 2017 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-28101431

RESUMEN

Accurate and early prediction of tissue viability is the most significant determinant of tissue flap survival in reconstructive surgery. Perturbation in tissue water content (TWC) is a generic component of the tissue response to such surgeries, and, therefore, may be an important diagnostic target for assessing the extent of flap viability in vivo. We have previously shown that reflective terahertz (THz) imaging, a non-ionizing technique, can generate spatially resolved maps of TWC in superficial soft tissues, such as cornea and wounds, on the order of minutes. Herein, we report the first in vivo pilot study to investigate the utility of reflective THz TWC imaging for early assessment of skin flap viability. We obtained longitudinal visible and reflective THz imagery comparing 3 bipedicled flaps (i.e. survival model) and 3 fully excised flaps (i.e. failure model) in the dorsal skin of rats over a postoperative period of 7 days. While visual differences between both models manifested 48 hr after surgery, statistically significant (p < 0.05, independent t-test) local differences in TWC contrast were evident in THz flap image sets as early as 24 hr. Excised flaps, histologically confirmed as necrotic, demonstrated a significant, yet localized, reduction in TWC in the flap region compared to non-traumatized skin. In contrast, bipedicled flaps, histologically verified as viable, displayed mostly uniform, unperturbed TWC across the flap tissue. These results indicate the practical potential of THz TWC sensing to accurately predict flap failure 24 hours earlier than clinical examination.

20.
Artif Cells Nanomed Biotechnol ; 44(7): 1774-82, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26508412

RESUMEN

We herein first report a method for the synthesis of chitosan (CHI)-folate conjugated colloidal ZnO-Mn(+2) quantum dots (QDs) bearing doxorubicin through chemical method (DOX/FA-CHI-QDs) for cancer therapy as well imaging purpose. The entrapment efficiency was determined to be 99.98 ± 0.012% (DOX/FA-CHI-QDs) and 92.0 ± 2.62% (DOX-QDs). The developed DOX/FA-CHI-QDs formulations depict the sustained release pattern at the lysosomal pH (pH 5.0). The DOX/FA-CHI-QDs showed enhanced cytotoxicity, cellular uptake and were most preferentially taken up by the cancerous cells via receptor-mediated endocytosis (RME) mechanism. Hence, the QD-based formulation is capable of targeting drug delivery and imaging the delivery process.


Asunto(s)
Antibióticos Antineoplásicos , Neoplasias de la Mama/tratamiento farmacológico , Doxorrubicina , Sistemas de Liberación de Medicamentos/métodos , Puntos Cuánticos/química , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacocinética , Antibióticos Antineoplásicos/farmacología , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Doxorrubicina/química , Doxorrubicina/farmacocinética , Doxorrubicina/farmacología , Femenino , Humanos , Células MCF-7
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