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1.
Adv Healthc Mater ; 13(9): e2303351, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38277705

RESUMEN

In vitro engineered skin models are emerging as an alternative platform to reduce and replace animal testing in dermatological research. Despite the progress made in recent years, considerable challenges still exist for the inclusion of diverse cell types within skin models. Blood vessels, in particular, are essential in maintaining tissue homeostasis and are one of many primary contributors to skin disease inception and progression. Substantial efforts in the past have allowed the successful fabrication of vascularized skin models that are currently utilized for disease modeling and drugs/cosmetics testing. This review first discusses the need for vascularization within tissue-engineered skin models, highlighting their role in skin grafting and disease pathophysiology. Second, the review spotlights the milestones and recent progress in the fabrication and utilization of vascularized skin models. Additionally, advances including the use of bioreactors, organ-on-a-chip devices, and organoid systems are briefly explored. Finally, the challenges and future outlook for vascularized skin models are addressed.


Asunto(s)
Enfermedades de la Piel , Ingeniería de Tejidos , Animales , Humanos , Piel , Neovascularización Patológica , Organoides
2.
Theor Appl Genet ; 136(11): 226, 2023 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-37847385

RESUMEN

KEY MESSAGE: Lack of function of a D-genome adult plant resistance gene upon introgression into durum wheat. The wheat Lr34/Yr18/Sr57/Pm38/Ltn1 adult plant resistance gene (Lr34), located on chromosome arm 7DS, provides broad spectrum, partial, adult plant resistance to leaf rust, stripe rust, stem rust and powdery mildew. It has been used extensively in hexaploid bread wheat (AABBDD) and conferred durable resistance for many decades. These same diseases also occur on cultivated tetraploid durum wheat and emmer wheat but transfer of D genome sequences to those subspecies is restricted due to very limited intergenomic recombination. Herein we have introgressed the Lr34 gene into chromosome 7A of durum wheat. Durum chromosome substitution line Langdon 7D(7A) was crossed to Cappelli ph1c, a mutant derivative of durum cultivar Cappelli homozygous for a deletion of the chromosome pairing locus Ph1. Screening of BC1F2 plants and their progeny by KASP and PCR markers, 90 K SNP genotyping and cytology identified 7A chromosomes containing small chromosome 7D fragments encoding Lr34. However, in contrast to previous transgenesis experiments in durum wheat, resistance to wheat stripe rust was not observed in either Cappelli/Langdon 7D(7A) or Bansi durum plants carrying this Lr34 encoding segment due to low levels of Lr34 gene expression.


Asunto(s)
Basidiomycota , Triticum , Triticum/genética , Pan , Genes de Plantas , Plantas/genética , Enfermedades de las Plantas/genética , Resistencia a la Enfermedad/genética
3.
ACS Biomater Sci Eng ; 9(8): 4878-4892, 2023 08 14.
Artículo en Inglés | MEDLINE | ID: mdl-37402206

RESUMEN

In vitro environments that realize biomimetic scaffolds, cellular composition, physiological shear, and strain are integral to developing tissue models of organ-specific functions. In this study, an in vitro pulmonary alveolar capillary barrier model is developed that closely mimics physiological functions by combining a synthetic biofunctionalized nanofibrous membrane system with a novel three-dimensional (3D)-printed bioreactor. The fiber meshes are fabricated from a mixture of polycaprolactone (PCL), 6-armed star-shaped isocyanate-terminated poly(ethylene glycol) (sPEG-NCO), and Arg-Gly-Asp (RGD) peptides by a one-step electrospinning process that offers full control over the fiber surface chemistry. The tunable meshes are mounted within the bioreactor where they support the co-cultivation of pulmonary epithelial (NCI-H441) and endothelial (HPMEC) cell monolayers at air-liquid interface under controlled stimulation by fluid shear stress and cyclic distention. This stimulation, which closely mimics blood circulation and breathing motion, is observed to impact alveolar endothelial cytoskeleton arrangement and improve epithelial tight junction formation as well as surfactant protein B production compared to static models. The results highlight the potential of PCL-sPEG-NCO:RGD nanofibrous scaffolds in combination with a 3D-printed bioreactor system as a platform to reconstruct and enhance in vitro models to bear a close resemblance to in vivo tissues.


Asunto(s)
Pulmón , Andamios del Tejido , Andamios del Tejido/química , Péptidos , Reactores Biológicos , Impresión Tridimensional
4.
ACS Appl Mater Interfaces ; 15(18): 21792-21803, 2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37127284

RESUMEN

Neural stem cells (NSCs) present attractive natural drug delivery systems (DDSs). Their migratory potential enables crossing of the blood-brain barrier and efficient and selective accumulation near malignant cells. Here, we present the potential of NSCs as DDSs for nucleoside analogue-conjugated nanogels (NGs). Two different approaches were investigated: the intracellular loading and extracellular cell surface decoration with NGs. For both designs, the tumor-specific migratory potentials of NSCs remained unchanged; however, the intracellular loading showed a shorter NG retention. The cell surface decoration protocol yielded a high loading capacity of 100% after 1 h and a prolonged drug retention. A redox-sensitive linker between NGs and the nucleoside analogue 5-ethynyl-2'-deoxycytidine (EdC) allowed a tumor environment-specific drug release and its efficient and preferential incorporation into the DNA of the tumor cells. Interestingly, the tumor-trafficking potentials of NSCs were significantly potentiated by irradiation of tumor cells. In conclusion, this study indicates the potentials of cell surface-decorated NSCs as DDSs for tumor-specific release, cellular uptake, and incorporation of EdC into DNA.


Asunto(s)
Neoplasias , Células-Madre Neurales , Humanos , Nanogeles , Nucleósidos , Sistemas de Liberación de Medicamentos
5.
Sci Rep ; 13(1): 8382, 2023 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-37225757

RESUMEN

Functional unit of many organs like lung, kidney, intestine, and eye have their endothelial and epithelial monolayers physically separated by a specialized extracellular matrix called the basement membrane. The intricate and complex topography of this matrix influences cell function, behavior and overall homeostasis. In vitro barrier function replication of such organs requires mimicking of these native features on an artificial scaffold system. Apart from chemical and mechanical features, the choice of nano-scale topography of the artificial scaffold is integral, however its influence on monolayer barrier formation is unclear. Though studies have reported improved single cell adhesion and proliferation in presence of pores or pitted topology, corresponding influence on confluent monolayer formation is not well reported. In this work, basement membrane mimic with secondary topographical cues is developed and its influence on single cells and their monolayers is investigated. We show that single cells cultured on fibers with secondary cues form stronger focal adhesions and undergo increased proliferation. Counterintuitively, absence of secondary cues promoted stronger cell-cell interaction in endothelial monolayers and promoted formation of integral tight barriers in alveolar epithelial monolayers. Overall, this work highlights the importance of choice of scaffold topology to develop basement barrier function in in vitro models.


Asunto(s)
Comunicación Celular , Adhesiones Focales , Adhesión Celular , Homeostasis , Membrana Basal
6.
Cureus ; 15(2): e35558, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37007314

RESUMEN

Background The diverse manifestations of urolithiasis provide very interesting epidemiological data. This has prompted various studies to look into the etiopathogenesis of renal stones, which is believed to be multifactorial, both exogenous and endogenous. VDR Fok1 is a risk factor for renal stone formation and could cause the formation of renal stones through the mechanism of crystal induction and crystallization in the urine. While a few recent studies have shown the role of heavy metals like cadmium and lead in the formation of renal stones, the current knowledge is still insufficient. Methods This case-control prospective study was conducted in Guru Teg Bahadur (GTB) Hospital, a tertiary care facility in Delhi with 30 cases and 30 controls. Patients visiting the department of surgery between November 2011 and April 2013 were enrolled in the study. Cases were defined as patients with renal stones diagnosed on the basis of history and radiological investigations. Controls were selected from the patients admitted to the department of surgery for reasons other than renal stones. The study protocol was approved by the Institutional Ethical Committee of the University College of Medical Sciences, GTB Hospital, Delhi. Written informed consent was obtained from all patients. A structured questionnaire was used to collect data. Metal levels were analyzed by an atomic absorption spectrophotometer (Shimadzu Flame AA-680, Shimadzu Corp., Kyoto, Japan) at Delhi University. The vitamin D receptor gene was measured using genomic DNA. Horizontal agarose gel electrophoresis was used for the quantification of the genomic DNA. Results There were 30 cases and 30 controls in the study. Stress was more prevalent among cases (63%) compared to controls (36%). Nearly 83% of cases had the ff allele of the Vitamin D receptor gene compared to 46% of controls. The median arsenic and lead levels were higher among cases compared to controls. In the unadjusted model of logistic regression, we found stressed patients had three times higher odds of developing renal stones compared to non-stressed patients (OR (95% CI): 2.98 (1.04-8.52); p=0.04). Similarly, patients with higher blood concentrations of arsenic and lead had higher odds of developing renal stones compared to those with lower concentrations.  Conclusions There was a definitive role of heavy metals, including lead, cadmium, and arsenic, seen with renal stones. A significant association was seen between the ff allele of VDR polymorphism (Fok1 enzymes) and patients with renal stones. Other parameters, including male and stress factors, seem to have an important role in renal stone formation.

7.
Small ; 19(14): e2205185, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36635040

RESUMEN

Nitric oxide (NO) plays a significant role in controlling the physiology and pathophysiology of the body, including the endothelial antiplatelet function and therefore, antithrombogenic property of the blood vessels. This property of NO can be exploited to prevent thrombus formation on artificial surfaces like extracorporeal membrane oxygenators, which when come into contact with blood lead to protein adsorption and thereby platelet activation causing thrombus formation. However, NO is extremely reactive and has a very short biological half-life in blood, so only endogenous generation of NO from the blood contacting material can result into a stable and kinetically controllable local delivery of NO. In this regards, highly hydrophilic bioactive nanogels are presented which can endogenously generate NO in blood plasma from endogenous NO-donors thereby maintaining a physiological NO flux. It is shown that NO releasing nanogels could initiate cGMP-dependent protein kinase signaling followed by phosphorylation of vasodilator-stimulated phosphoprotein in platelets. This prevents platelet activation and aggregation even in presence of highly potent platelet activators like thrombin, adenosine 5'-diphosphate, and U46619 (thromboxane A2 mimetic).


Asunto(s)
Óxido Nítrico , Trombosis , Humanos , Óxido Nítrico/metabolismo , Nanogeles , GMP Cíclico/metabolismo , Plaquetas/metabolismo , Endotelio/metabolismo
8.
J Biomol Struct Dyn ; 41(21): 11862-11871, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36597903

RESUMEN

Single stranded DNA (ssDNA)/RNA aptamers, are screened through the labor intensive, iterative Systematic Evolution of Ligand by Exponential Enrichment process (SELEX) method. Complete sequence of screened aptamers never interacts with target or participates in final structure. Hence, in silico tools can be used to redesign a short length aptamer from previously reported aptamers which can have high affinity and specificity to the target. This approach is fast, cost effective, and less laborious than in vitro SELEX towards finding an aptamer sequence with better affinity with the target. Here, Staphylococcal enterotoxin type A (SEA) was used as target. A total of nine aptamers reported for different Staphylococcal food poisoning (SFP) enterotoxins were used as a starting pool. The aptamers were variously truncations and thoroughly analyzed through in silico methods. Three truncated aptamers namely AptSEA1.4, AptSEA2.4 and AptSEA8.4 were found to show higher affinity with target SEA. The computational data was also validated with DOT BLOT assay complemented with image analysis. These results also confirmed that the % specific binding and the dissociation constant (Kd) of truncated aptamers AptSEA1.4, AptSEA2.4 and AptSEA8.4 was better than their original counterparts. The truncated aptamers showed great promise to be used as a capture reagent in developing a sensitive assay for detection of SEA.Communicated by Ramaswamy H. Sarma.


Asunto(s)
Aptámeros de Nucleótidos , ADN de Cadena Simple , Enterotoxinas/análisis , Enterotoxinas/genética , Aptámeros de Nucleótidos/química
9.
J Reprod Infant Psychol ; 41(1): 43-52, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34338099

RESUMEN

OBJECTIVE: : To assess the incidence of postpartum depression, maternal confidence about parenting and maternal-infant bonding characteristics in first-time mothers. BACKGROUND: : First-time mothers are usually unprepared for the transition into motherhood and may find it difficult to cope-up with this challenge leading to parenting stress, maternal-infant bonding disorders, and mental health problems. METHODS: : This cross-sectional study was conducted in a tertiary centre in South India, on 151 primigravid mothers who delivered a live-born healthy infant after 37 weeks' gestation. Assessment was done using Patient Health Questionnaire scale, Tamil version of the Postpartum Bonding Questionnaire and Maternal Confidence Questionnaire on the 2nd or 3rd postpartum day. RESULTS: : Incidence of postpartum depression was found to be 18.5%, with 6% having features of severe depression. All mothers had good perceived maternal confidence. Nearly one-third had one or more of the maternal-infant bonding disorders. Those who had a vaginal delivery were associated with bonding disorders (OR = 10.3; 95% CI 2.13-47.21) whereas moderate to severe postpartum depression was not associated with it on multivariate analysis. CONCLUSION: : First-time mothers were found to have good confidence in the transition to motherhood. However, the high incidence of maternal-infant bonding difficulty, especially in those with moderate to severe depression, suggests the need for initiating systematic and routine screening for postpartum mental health problems.


Asunto(s)
Depresión Posparto , Madres , Lactante , Embarazo , Femenino , Humanos , Madres/psicología , Estudios Transversales , Relaciones Madre-Hijo/psicología , India , Periodo Posparto , Depresión Posparto/psicología , Estado de Salud
10.
Cureus ; 14(12): e32222, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36479260

RESUMEN

Background An operative note (op note) is a vital medical record of remarkable clinical, medico-legal and academic relevance. The Royal College of Surgeons (RCS) has set out a guideline to standardise op notes. This closed-loop audit assessed the compliance of op notes completed in our local hospital against the guidance set by RCS with the view to identify deficiencies and improve practice. Methods A retrospective review of general surgery operative notes was carried out to access their various characteristics against RCS guidance. Two additional parameters were assessed, namely, 'cadre of the surgeon that completed the op note' and 'use of abbreviations'. To improve compliance with RCS guidelines, an electronic proforma (EP) that included all the 18 characteristics listed in good surgical practice was implemented and a re-audit was undertaken six months afterwards. Results A total of 200 op notes were reviewed, 98 during the initial audit cycle and 102 at the re-audit. Seventy-eight per cent (78%) of the op notes were written by trainees. At the initial audit, seven parameters performed poorly, with compliance ranging between 5.1% and 76.5%. The re-audit demonstrated improved adherence to guidelines following the implementation of the EP, as well as a reduction in the use of abbreviations. The overall compliance improved from roughly 80% to >95%. Conclusion A sustainable change was achieved through the implementation of EP with improvement demonstrated in content and structure. The need to provide teaching to trainees who are responsible for writing a vast majority of op notes was identified.

11.
Adv Drug Deliv Rev ; 189: 114504, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35998825

RESUMEN

The tumor microenvironment (TME) is emerging as one of the primary barriers in cancer therapy. Cancer-associated fibroblasts (CAF) are a common inhabitant of the TME in several tumor types and play a critical role in tumor progression and drug resistance via different mechanisms such as desmoplasia, angiogenesis, immune modulation, and cancer metabolism. Due to their abundance and significance in pro-tumorigenic mechanisms, CAF are gaining attention as a diagnostic target as well as to improve the efficacy of cancer therapy by their modulation. In this review, we highlight existing imaging techniques that are used for the visualization of CAF and CAF-induced fibrosis and provide an overview of compounds that are known to modulate CAF activity. Subsequently, we also discuss CAF-targeted and CAF-modulating nanocarriers. Finally, our review addresses ongoing challenges and provides a glimpse into the prospects that can spearhead the transition of CAF-targeted therapies from opportunity to reality.


Asunto(s)
Fibroblastos Asociados al Cáncer , Neoplasias , Fibroblastos Asociados al Cáncer/metabolismo , Fibroblastos , Humanos , Neoplasias/diagnóstico por imagen , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Neovascularización Patológica/patología , Microambiente Tumoral
12.
Biomacromolecules ; 23(8): 3081-3103, 2022 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-35839343

RESUMEN

Advancements in the field of tissue engineering have led to the elucidation of physical and chemical characteristics of physiological basement membranes (BM) as specialized forms of the extracellular matrix. Efforts to recapitulate the intricate structure and biological composition of the BM have encountered various advancements due to its impact on cell fate, function, and regulation. More attention has been paid to synthesizing biocompatible and biofunctional fibrillar scaffolds that closely mimic the natural BM. Specific modifications in biomimetic BM have paved the way for the development of in vitro models like alveolar-capillary barrier, airway models, skin, blood-brain barrier, kidney barrier, and metastatic models, which can be used for personalized drug screening, understanding physiological and pathological pathways, and tissue implants. In this Review, we focus on the structure, composition, and functions of in vivo BM and the ongoing efforts to mimic it synthetically. Light has been shed on the advantages and limitations of various forms of biomimetic BM scaffolds including porous polymeric membranes, hydrogels, and electrospun membranes This Review further elaborates and justifies the significance of BM mimics in tissue engineering, in particular in the development of in vitro organ model systems.


Asunto(s)
Matriz Extracelular , Ingeniería de Tejidos , Membrana Basal/química , Diferenciación Celular , Matriz Extracelular/química , Piel , Andamios del Tejido/química
13.
Soft Matter ; 18(22): 4315-4324, 2022 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-35621021

RESUMEN

The use of polymeric materials in biomedical applications requires a judicious control of surface properties as they are directly related to cellular interactions and biocompatibility. The most desired chemical surface properties include hydrophilicity and the presence of functional groups for surface modification. In this work, we describe a method to graft a highly stable, ultra-thin, amine-functional hydrogel layer onto highly inert surfaces of poly(tetrafluoroethylene) (PTFE), poly(vinylidene fluoride) (PVDF), and poly(4-methyl-1-pentene) (PMP or TPX). Covalent grafting is realized with hydrophilic poly(vinylamine-co-acetamide)s by C-H insertion crosslinking (CHic) chemistry initiated by UV light. These polyvinylamides carry tetrafluorophenyl azide groups as photo or thermo activated binding sites and contain further free amine groups, which can be used to bind peptides such as biological ligands, polysaccharides, or other hydrogel layers. The covalently bound surface layers resist intensive Soxhlet extraction confirming the stability of the coating. Fluorescent staining verified the accessibility of free primary amine groups, which can be used for the functionalization of the surface with bioactive molecules. The coating demonstrates hydrophobic wetting behavior when conditioned in air and hydrophilic wetting behavior when conditioned in water showing the presence of loosely crosslinked polymer chains that can re-orient. We believe that the reported application of CHic for the surface modification of fluorinated polymers like PTFE and PVDF as well as TPX can form the basis for advanced biocompatible and biofunctional surface engineering.


Asunto(s)
Hidrogeles , Polímeros , Aminas , Polímeros de Fluorocarbono , Metilgalactósidos , Polímeros/química , Politetrafluoroetileno/química , Polivinilos/química , Propiedades de Superficie
14.
Small ; 18(25): e2200673, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35527333

RESUMEN

Endogenous targeted radiotherapy is emerging as an integral modality to treat a variety of cancer entities. Nevertheless, despite the positive clinical outcome of the treatment using radiolabeled peptides, small molecules, antibodies, and nanobodies, a high degree of hepatotoxicity and nephrotoxicity still persist. This limits the amount of dose that can be injected. In an attempt to mitigate these side effects, the use of nanocarriers such as nanoparticles (NPs), dendrimers, micelles, liposomes, and nanogels (NGs) is currently being explored. Nanocarriers can prolong circulation time and tumor retention, maximize radiation dosage, and offer multifunctionality for different targeting strategies. In this review, the authors first provide a summary of radiation therapy and imaging and discuss the new radiotracers that are used preclinically and clinically. They then highlight and identify the advantages of radio-nanomedicine and its potential in overcoming the limitations of endogenous radiotherapy. Finally, the review points to the ongoing efforts to maximize the use of radio-nanomedicine for efficient clinical translation.


Asunto(s)
Antineoplásicos , Nanopartículas , Neoplasias , Antineoplásicos/uso terapéutico , Portadores de Fármacos , Humanos , Micelas , Nanomedicina/métodos , Nanopartículas/química , Neoplasias/diagnóstico por imagen , Neoplasias/tratamiento farmacológico , Neoplasias/radioterapia , Péptidos/uso terapéutico , Medicina de Precisión
15.
Angew Chem Int Ed Engl ; 61(20): e202116653, 2022 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-35274425

RESUMEN

Peptide receptor radionuclide therapy is used to treat solid tumors by locally delivering radiation. However, due to nephro- and hepato-toxicity, it is limited by its dosage. To amplify radiation damage to tumor cells, radiolabeled nanogels can be used. We show that by tuning the mechanical properties of nanogels significant enhancement in circulation half-life of the gel could be achieved. We demonstrate why and how small changes in the mechanical properties of the nanogels influence its cellular fate. Nanogels with a storage modulus of 37 kPa were minimally phagocytosed by monocytes and macrophages compared to nanogels with 93 kPa modulus. Using PET/CT a significant difference in the blood circulation time of the nanogels was shown. Computer simulations affirmed the results and predicted the mechanism of cellular uptake of the nanogels. Altogether, this work emphasizes the important role of elasticity even for particles that are inherently soft such as nano- or microgels.


Asunto(s)
Microgeles , Tomografía Computarizada por Tomografía de Emisión de Positrones , Tiempo de Circulación Sanguínea , Elasticidad , Nanogeles
16.
Membranes (Basel) ; 12(1)2022 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-35054599

RESUMEN

BACKGROUND: Clot formation on foreign surfaces of extracorporeal membrane oxygenation systems is a frequent event. Herein, we show an approach that mimics the enzymatic process of endogenous nitric oxide (NO) release on the oxygenator membrane via a biomimetic, non-fouling microgel coating to spatiotemporally inhibit the platelet (PLT) activation and improve antithrombotic properties. This study aims to evaluate the potential of this biomimetic coating towards NO-mediated PLT inhibition and thereby the reduction of clot formation under flow conditions. METHODS: Microgel-coated (NOrel) or bare (Control) poly(4-methyl pentene) (PMP) fibers were inserted into a test channel and exposed to a short-term continuous flow of human blood. The analysis included high-resolution PLT count, pooled PLT activation via ß-Thromboglobulin (ß-TG) and the visualization of remnants and clots on the fibers using scanning electron microscopy (SEM). RESULTS: In the Control group, PLT count was significantly decreased, and ß-TG concentration was significantly elevated in comparison to the NOrel group. Macroscopic and microscopic visualization showed dense layers of stable clots on the bare PMP fibers, in contrast to minimal deposition of fibrin networks on the coated fibers. CONCLUSION: Endogenously NO-releasing microgel coating inhibits the PLT activation and reduces the clot formation on PMP fibers under dynamic flow.

17.
Perfusion ; 37(2): 134-143, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33475044

RESUMEN

INTRODUCTION: Due to improved technology and increased application the mortality during extracorporeal membrane oxygenation (ECMO) is constantly declining. Nevertheless, complications including haemorrhage or thrombus formation remain frequent. Local mitigation of coagulation within an ECMO system to prevent thrombus formation on ECMO components and optimizing systemic anticoagulation is an approach to reduce clotting and bleeding complications at once. Foreign surfaces of ECMO systems, activate platelets (PLTs), which besides their major role in coagulation, can trigger the formation of neutrophil extracellular traps (NETs) contributing to robust thrombus formation. The impact of a reduced PLT count on PLT activation and NET formation is of paramount importance and worth investigating. METHODS: In this study platelet poor (PLT-) and native (PLT+) heparinized human blood was circulated in two identical in vitro test circuits for ECMO devices for 6 hours. PLT reduction was achieved by a centrifugation protocol prior to the experiments. To achieve native coagulation characteristics within the test circuits, the initial heparin dose was antagonized by continuous protamine administration. RESULTS: The PLT- group showed significantly lower platelet activation, basal NET formation and limited clot stability measured via thromboelastometry. Fluorescent and scanning electron microscope imaging showed differences in clot composition. Both groups showed equal clot formation within the circuit. CONCLUSIONS: This study demonstrated that the reduction of PLTs within an ECMO system is associated with limited PLT activation and NET formation, which reduces clot stability but is not sufficient to inhibit clot formation per se.


Asunto(s)
Trampas Extracelulares , Trombosis , Coagulación Sanguínea/fisiología , Humanos , Activación Plaquetaria , Recuento de Plaquetas
18.
Biomater Sci ; 10(1): 85-99, 2021 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-34812809

RESUMEN

Neutrophil extracellular traps (NETs) are web-like chromatin structures produced and liberated by neutrophils under inflammatory conditions which also promote the activation of the coagulation cascade and thrombus formation. The formation of NETs is quite prominent when blood comes in contact with artificial surfaces like extracorporeal circuits, oxygenator membranes, or intravascular grafts. DNase I as a factor of the host defense system, digests the DNA backbone of NETs, which points out its treatment potential for NET-mediated thrombosis. However, the low serum stability of DNase I restricts its clinical/therapeutic applications. To improve the bioavailability of the enzyme, DNase I was conjugated to the microgels (DNase I MG) synthesized from highly hydrophilic N-(2-hydroxypropyl) methacrylamide (HPMA) and zwitterionic carboxybetaine methacrylamide (CBMAA). The enzyme was successfully conjugated to the microgels without any alternation to its secondary structure. The Km value representing the enzymatic activity of the conjugated DNase I was calculated to be 0.063 µM demonstrating a high enzyme-substrate affinity. The DNase I MGs were protein repellant and were able to digest NETs more efficiently compared to free DNase in a biological media, remarkably even after long-term exposure to the stimulated neutrophils continuously releasing NETs. Overall, the conjugation of DNase I to a non-fouling microgel provides a novel biohybrid platform that can be exploited as non-thrombogenic active microgel-based coatings for blood-contacting surfaces to reduce the NET-mediated inflammation and microthrombi formation.


Asunto(s)
Trampas Extracelulares , Microgeles , Trombosis , Desoxirribonucleasa I , Humanos , Neutrófilos
19.
Sci Rep ; 11(1): 21966, 2021 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-34754042

RESUMEN

Breast cancer cells (BCCs) preferentially metastasize to bone. It is known that BCCs remotely primes the distant bone site prior to metastasis. However, the reciprocal influence of bone cells on the primary tumor is relatively overlooked. Here, to study the bone-tumor paracrine influence, a tri-cellular 3-D vascularized breast cancer tissue (VBCTs) model is engineered which comprised MDA-MB231, a triple-negative breast cancer cells (TNBC), fibroblasts, and endothelial cells. This is indirectly co-cultured with osteoblasts (OBs), thereby constituting a complex quad-cellular tumor progression model. VBCTs alone and in conjunction with OBs led to abnormal vasculature and reduced vessel density but enhanced VEGF production. A total of 1476 significantly upregulated and 775 downregulated genes are identified in the VBCTs exposed to OBs. HSP90N, CYCS, RPS27A, and EGFR are recognized as upregulated hub-genes. Kaplan Meier plot shows HSP90N to have a significant outcome in TNBC patient survivability. Furthermore, compared to cancer tissues without vessels, gene analysis recognized 1278 significantly upregulated and 566 downregulated genes in VBCTs. DKK1, CXCL13, C3 protein and BMP4 are identified to be downregulated hub genes in VBCTs. Together, a multi-cellular breast cancer model and culture protocols are established to study pre-metastatic events in the presence of OBs.


Asunto(s)
Metástasis de la Neoplasia , Neovascularización Patológica , Osteoblastos/patología , Neoplasias de la Mama Triple Negativas/irrigación sanguínea , Línea Celular Tumoral , Técnicas de Cocultivo , Femenino , Humanos , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/patología , Microambiente Tumoral
20.
Appl Microbiol Biotechnol ; 105(23): 8895-8906, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34714365

RESUMEN

Canine parvovirus-2 (CPV-2) is ubiquitously distributed in dog population worldwide causing a severe and often fatal gastroenteritis. Owing to its highly contagious nature, rapid detection of CPV is crucial in effective control of the disease. Aptamers have emerged as potential alternative to antibodies as affinity reagents in diagnostic field. Present study was aimed to select and validate ssDNA aptamers specific to CPV. Systematic evolution of ligands through exponential enrichment (SELEX) method was employed for selection of CPV structural protein (VP2) specific DNA aptamers. SELEX was performed using a pool of ssDNA library comprising 30 random nucleotide region. A total of seven rounds of SELEX were performed using VP2 protein as target antigen which yielded ten aptamers (1A-10A) with distinct sequences. Target binding of all ten aptamers was assessed by dot blot and enzyme-linked oligonucleotide assay (ELONA) which revealed that 5A, 6A, 9A, and 10A were superior binders. In silico analysis of the aptamers revealed the existence of binding site on VP2 protein, and binding pattern was similar to in vitro findings. The affinity (KD) of all these four binders against CPV was evaluated by ELONA indicating relatively higher affinity of 6A and 10A than remaining two DNA sequences. Out of which, aptamer 6A displayed cross-reactivity with canine distemper virus and canine corona virus. Hence, aptamer 10A was considered as better binding sequence having high specificity and affinity for CPV. The study confirms the future utility of selected aptamers in development of a reliable diagnostic for rapid detection of CPV. KEY POINTS: • Canine parvovirus-specific ssDNA aptamers were identified with nanomolar affinity (100-150 nM). • Three aptamers displayed negligible cross-reactivity with other related viruses. • Aptamer 10A displayed high binding affinity and specificity to CPV.


Asunto(s)
Aptámeros de Nucleótidos , Parvovirus Canino , Animales , ADN de Cadena Simple/genética , Perros , Biblioteca de Genes , Parvovirus Canino/genética , Técnica SELEX de Producción de Aptámeros
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