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1.
Appl Clin Inform ; 15(2): 404-413, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38777326

RESUMO

OBJECTIVES: There is limited research on suicide risk screening (SRS) among head and neck cancer (HNC) patients, a population at increased risk for suicide. To address this gap, this single-site mixed methods study assessed oncology professionals' perspectives about the feasibility, acceptability, and appropriateness of an electronic SRS program that was implemented as a part of routine care for HNC patients. METHODS: Staff who assisted with SRS implementation completed (e.g., nurses, medical assistants, advanced practice providers, physicians, social workers) a one-time survey (N = 29) and interview (N = 25). Quantitative outcomes were assessed using previously validated feasibility, acceptability, and appropriateness measures. Additional qualitative data were collected to provide context for interpreting the scores. RESULTS: Nurses and medical assistants, who were directly responsible for implementing SRS, reported low feasibility, acceptability, and appropriateness, compared with other team members (e.g., physicians, social workers, advanced practice providers). Team members identified potential improvements needed to optimize SRS, such as hiring additional staff, improving staff training, providing different modalities for screening completion among individuals with disabilities, and revising the patient-reported outcomes to improve suicide risk prediction. CONCLUSION: Staff perspectives about implementing SRS as a part of routine cancer care for HNC patients varied widely. Before screening can be implemented on a larger scale for HNC and other cancer patients, additional implementation strategies may be needed that optimize workflow and reduce staff burden, such as staff training, multiple modalities for completion, and refined tools for identifying which patients are at greatest risk for suicide.


Assuntos
Neoplasias de Cabeça e Pescoço , Humanos , Neoplasias de Cabeça e Pescoço/diagnóstico , Medição de Risco/métodos , Suicídio , Programas de Rastreamento , Prevenção do Suicídio , Masculino , Feminino
2.
Support Care Cancer ; 31(8): 483, 2023 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-37480364

RESUMO

BACKGROUND: Promoting smoking cessation is recognized as an essential part of cancer care. Moffitt Cancer Center, supported by the National Cancer Institute Cancer Moonshot Cancer Center Cessation Initiative, developed and implemented an opt-out-based automatic electronic health record (EHR)-mediated referral (e-referral) system for Tobacco Quitline services along with options for local group cessation support and an in-house tobacco treatment specialist. This study evaluated barriers and facilitators for implementation of the e-referral system. METHOD: Steering committee members (N=12) responsible for developing and implementing the new clinical workflow and nurses (N=12) who were expected to use the new e-referral system completed semi-structured interviews. Qualitative thematic content analyses were conducted. RESULTS: Interviewees perceived the e-referral system as an effective strategy for identifying and referring smokers to cessation services. However, barriers were noted including competing demands and perceptions that smoking cessation was a low priority and that some patients were likely to have low motivation to quit smoking. Suggestions to improve future implementation and sustainability included providing regular trainings and e-referral outcome reports and increasing the visibility of the e-referral system within the EHR. CONCLUSION: Initial implementation of the e-referral system was perceived as successful; however, additional implementation strategies are needed to ensure sustainability at both the clinician and system levels. Recommendations for future modifications include providing regular clinician trainings and developing a fully closed-loop system. Implications for cancer survivors Initial implementation of an e-referral system for smoking cessation for cancer patients revealed opportunities to improve the smoking cessation referral process at cancer centers.


Assuntos
Sobreviventes de Câncer , Neoplasias , Abandono do Hábito de Fumar , Humanos , Fumar , Registros Eletrônicos de Saúde , Encaminhamento e Consulta , Neoplasias/terapia
3.
Comput Biol Med ; 162: 107033, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37271110

RESUMO

Ear prostheses are commonly used for restoring aesthetics to those suffering missing or malformed external ears. Traditional fabrication of these prostheses is labour intensive and requires expert skill from a prosthetist. Advanced manufacturing including 3D scanning, modelling and 3D printing has the potential to improve this process, although more work is required before it is ready for routine clinical use. In this paper, we introduce a parametric modelling technique capable of producing high quality 3D models of the human ear from low-fidelity, frugal, patient scans; significantly reducing time, complexity and cost. Our ear model can be tuned to fit the frugal low-fidelity 3D scan through; (a) manual tuning, or (b) our automated particle filter approach. This potentially enables low-cost smartphone photogrammetry-based 3D scanning for high quality personalised 3D printed ear prosthesis. In comparison to standard photogrammetry, our parametric model improves completeness, from (81 ± 5)% to (87 ± 4)%, with only a modest reduction in accuracy, with root mean square error (RMSE) increasing from (1.0 ± 0.2) mm to (1.5 ± 0.2) mm (relative to metrology rated reference 3D scans, n = 14). Despite this reduction in the RMS accuracy, our parametric model improves the overall quality, realism, and smoothness. Our automated particle filter method differs only modestly compared to manual adjustments. Overall, our parametric ear model can significantly improve quality, smoothness and completeness of 3D models produced from 30-photograph photogrammetry. This enables frugal high-quality 3D ear models to be produced for use in the advanced manufacturing of ear prostheses.


Assuntos
Membros Artificiais , Impressão Tridimensional , Humanos , Cintilografia
4.
JCO Oncol Pract ; 19(6): e892-e903, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36395441

RESUMO

PURPOSE: There has been limited study of the implementation of suicide risk screening for patients with head and neck cancer (HNC) as a part of routine care. To address this gap, this study assessed oncology providers' and professionals' perspectives about barriers and facilitators of implementing a suicide risk screening among patients with HNC. MATERIALS AND METHODS: All patients with HNC with an in-person visit completed a suicide risk screening on an electronic tablet. Patients reporting passive death wish were then screened for active suicidal ideation and referred for appropriate intervention. Interviews were conducted with 25 oncology providers and professionals who played a key role in implementation including nurses, medical assistants, patient access representatives, advanced practice providers, physicians, social workers, and informatics staff. The interview guide was based on the Consolidated Framework for Implementation Research. Interviews were transcribed and analyzed for themes. RESULTS: Participants identified multilevel implementation barriers, such as intervention level (eg, patient difficulty with using a tablet), process level (eg, limited nursing engagement), organizational level (eg, limited clinic Wi-Fi connectivity), and individual level (eg, low clinician self-efficacy for interpreting and acting upon patient-reported outcome scores). Participants noted facilitators, such as effective care coordination across nursing and social work staff and the opportunity for patients to be screened multiple times. Participants recommended strengthening patient and clinician education and providing patients with other modalities for data entry (eg, desktop computer in the waiting room). CONCLUSION: Participants identified important intervention modifications that may be needed to optimize suicide risk screening in cancer care settings.


Assuntos
Neoplasias de Cabeça e Pescoço , Médicos , Suicídio , Humanos , Detecção Precoce de Câncer
5.
Nature ; 606(7912): 197-203, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35585235

RESUMO

Eukaryotic genomes are compacted into loops and topologically associating domains (TADs)1-3, which contribute to transcription, recombination and genomic stability4,5. Cohesin extrudes DNA into loops that are thought to lengthen until CTCF boundaries are encountered6-12. Little is known about whether loop extrusion is impeded by DNA-bound machines. Here we show that the minichromosome maintenance (MCM) complex is a barrier that restricts loop extrusion in G1 phase. Single-nucleus Hi-C (high-resolution chromosome conformation capture) of mouse zygotes reveals that MCM loading reduces CTCF-anchored loops and decreases TAD boundary insulation, which suggests that loop extrusion is impeded before reaching CTCF. This effect extends to HCT116 cells, in which MCMs affect the number of CTCF-anchored loops and gene expression. Simulations suggest that MCMs are abundant, randomly positioned and partially permeable barriers. Single-molecule imaging shows that MCMs are physical barriers that frequently constrain cohesin translocation in vitro. Notably, chimeric yeast MCMs that contain a cohesin-interaction motif from human MCM3 induce cohesin pausing, indicating that MCMs are 'active' barriers with binding sites. These findings raise the possibility that cohesin can arrive by loop extrusion at MCMs, which determine the genomic sites at which sister chromatid cohesion is established. On the basis of in vivo, in silico and in vitro data, we conclude that distinct loop extrusion barriers shape the three-dimensional genome.


Assuntos
Proteínas de Ciclo Celular , Proteínas Cromossômicas não Histona , DNA , Proteínas de Manutenção de Minicromossomo , Animais , Fator de Ligação a CCCTC/metabolismo , Proteínas de Ciclo Celular/metabolismo , Cromátides/química , Cromátides/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , DNA/química , DNA/metabolismo , Fase G1 , Células HCT116 , Humanos , Camundongos , Componente 3 do Complexo de Manutenção de Minicromossomo/química , Componente 3 do Complexo de Manutenção de Minicromossomo/metabolismo , Proteínas de Manutenção de Minicromossomo/química , Proteínas de Manutenção de Minicromossomo/metabolismo , Complexos Multienzimáticos/química , Complexos Multienzimáticos/metabolismo , Conformação de Ácido Nucleico , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/metabolismo , Coesinas
6.
Ultrasound Med Biol ; 48(3): 450-459, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34848081

RESUMO

Three-dimensional imaging and advanced manufacturing are being applied in health care research to create novel diagnostic and surgical planning methods, as well as personalised treatments and implants. For ear reconstruction, where a cartilage-shaped implant is embedded underneath the skin to re-create shape and form, volumetric imaging and segmentation processing to capture patient anatomy are particularly challenging. Here, we introduce 3-D ultrasound (US) as an available option for imaging the external ear and underlying auricular cartilage structure, and compare it with computed tomography (CT) and magnetic resonance imaging (MRI) against micro-CT (µCT) as a high-resolution reference (gold standard). US images were segmented to create 3-D models of the auricular cartilage and compared against models generated from µCT to assess accuracy. We found that CT was significantly less accurate than the other methods (root mean square [RMS]: 1.30 ± 0.5 mm) and had the least contrast between tissues. There was no significant difference between MRI (RMS: 0.69 ± 0.2 mm) and US (0.55 ± 0.1 mm). US was also the least expensive imaging method at half the cost of MRI. These results unveil a novel use of ultrasound imaging that has not been presented before, as well as support its more widespread use in biofabrication as a low-cost imaging technique to create patient-specific 3D models and implants.


Assuntos
Cartilagem da Orelha , Procedimentos de Cirurgia Plástica , Cartilagem da Orelha/cirurgia , Orelha Externa/cirurgia , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Próteses e Implantes , Procedimentos de Cirurgia Plástica/métodos , Ultrassonografia
8.
Curr Biol ; 31(18): 4038-4051.e7, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34314679

RESUMO

The frequency of egg aneuploidy and trisomic pregnancies increases with maternal age. To what extent individual approaches can delay the "maternal age effect" is unclear because multiple causes contribute to chromosomal abnormalities in mammalian eggs. We propose that ovulation frequency determines the physiological aging of oocytes, a key aspect of which is the ability to accurately segregate chromosomes and produce euploid eggs. To test this hypothesis, ovulations were reduced using successive pregnancies, hormonal contraception, and a pre-pubertal knockout mouse model, and the effects on chromosome segregation and egg ploidy were examined. We show that each intervention reduces chromosomal abnormalities in eggs of aged mice, suggesting that ovulation reduction delays oocyte aging. The protective effect can be partly explained by retention of chromosomal Rec8-cohesin that maintains sister chromatid cohesion in meiosis. In addition, single-nucleus Hi-C (snHi-C) revealed deterioration in the 3D chromatin structure including an increase in extruded loop sizes in long-lived oocytes. Artificial cleavage of Rec8 is sufficient to increase extruded loop sizes, suggesting that cohesin complexes maintaining cohesion restrict loop extrusion. These findings suggest that ovulation suppression protects against Rec8 loss, thereby maintaining both sister chromatid cohesion and 3D chromatin structure and promoting production of euploid eggs. We conclude that the maternal age effect can be delayed in mice. An implication of this work is that long-term ovulation-suppressing conditions can potentially reduce the risk of aneuploid pregnancies at advanced maternal age.


Assuntos
Meiose , Inibição da Ovulação , Animais , Proteínas de Ciclo Celular/genética , Aberrações Cromossômicas , Segregação de Cromossomos , Feminino , Mamíferos , Idade Materna , Camundongos , Oócitos/fisiologia
9.
J Plast Reconstr Aesthet Surg ; 74(11): 3066-3072, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34088646

RESUMO

Three-dimensional (3D) scanning technologies, such as medical imaging and surface scanning, have important applications for capturing patient anatomy to create personalised prosthetics. Digital approaches for capturing anatomical detail as opposed to traditional, invasive impression techniques significantly reduces turnaround times and lower production costs while still maintaining the high aesthetic quality of the end product. While previous case studies utilise expensive 3D scanning and modelling frameworks, their clinical translation is limited due to high equipment costs. In this study, we develop and validate a low-cost framework for clinical 3D scanning of the external ear using photogrammetry and a smartphone camera. We recruited five novice operators who watched an instructional video before scanning 20 healthy adult participant ears who did not have microtia. Our results show that the smartphone-based photogrammetry methodology produces 3D scans of the external ear that were accurate to (1.5 ± 0.4) mm and were (71 ± 14) % complete compared with those from a gold standard reference scanner, with no significant difference observed between operators. A moderate to strong interrater reliability was determined for all novice operators, suggesting that all novice operators were able to capture repeatable scans. The development of this smartphone photogrammetry approach has the potential to provide a non-invasive, inexpensive and accessible means to capture patient morphology for use in clinical assessment and personalised device manufacture, specifically for ear prostheses. We also demonstrate that inexperienced operators can rapidly learn and apply smartphone photogrammetry for accurate and reliable scans of the external ear with important applications for future clinical translation.


Assuntos
Orelha Externa/anatomia & histologia , Imageamento Tridimensional , Fotogrametria/métodos , Smartphone , Microtia Congênita/diagnóstico por imagem , Feminino , Humanos , Masculino , Adulto Jovem
10.
J Prosthodont ; 29(9): 818-825, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33089546

RESUMO

PURPOSE: Three-dimensional (3D) facial scanning is an emerging clinical tool to capture external anatomical features for quantitative assessment and treatment in a wide range of clinical settings. MATERIALS AND METHODS: In this study, an economical approach for rapid scanning of faces in the clinic was developed and validated to record valuable 3D patient data using smartphone cameras and photogrammetry software. Five novice operators were recruited to watch an instructional video developed on the technique before scanning 20 healthy adult participants. RESULTS: The smartphone-based photogrammetry approach produced scans with 1.3 mm (±0.3 mm) accuracy in comparison to a metrology-rated gold standard device and were 88% (±14%) complete, with no significant difference observed between operators. A moderate to strong intrarater reliability was determined for all novice operators, suggesting that first-use operators can capture consistent scans based on watching an instructional video. CONCLUSION: Smartphone photogrammetry could provide a rapid, noninvasive and economical method to capture patient morphological data for clinical assessment and personalized device manufacture. Inexperienced operators can quickly learn and utilize smartphone photogrammetry to provide accurate and reliable facial scans, essential for future clinical translation.


Assuntos
Imageamento Tridimensional , Smartphone , Adulto , Humanos , Fotogrametria , Reprodutibilidade dos Testes , Software
11.
Biotechnol Adv ; 45: 107652, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33122013

RESUMO

Advanced manufacturing and 3D printing are transformative technologies currently undergoing rapid adoption in healthcare, a traditionally non-manufacturing sector. Recent development in this field, largely enabled by merging different disciplines, has led to important clinical applications from anatomical models to regenerative bioscaffolding and devices. Although much research to-date has focussed on materials, designs, processes, and products, little attention has been given to the design and requirements of facilities for enabling clinically relevant biofabrication solutions. These facilities are critical to overcoming the major hurdles to clinical translation, including solving important issues such as reproducibility, quality control, regulations, and commercialization. To improve process uniformity and ensure consistent development and production, large-scale manufacturing of engineered tissues and organs will require standardized facilities, equipment, qualification processes, automation, and information systems. This review presents current and forward-thinking guidelines to help design biofabrication laboratories engaged in engineering model and tissue constructs for therapeutic and non-therapeutic applications.


Assuntos
Bioimpressão , Laboratórios , Impressão Tridimensional , Reprodutibilidade dos Testes , Engenharia Tecidual
12.
Adv Mater ; 32(42): e2001122, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32909302

RESUMO

Millions of people worldwide experience disfigurement due to cancers, congenital defects, or trauma, leading to significant psychological, social, and economic disadvantage. Prosthetics aim to reduce their suffering by restoring aesthetics and function using synthetic materials that mimic the characteristics of native tissue. In the 1900s, natural materials used for thousands of years in prosthetics were replaced by synthetic polymers bringing about significant improvements in fabrication and greater realism and utility. These traditional methods have now been disrupted by the advanced manufacturing revolution, radically changing the materials, methods, and nature of prosthetics. In this report, traditional synthetic polymers and advanced prosthetic materials and manufacturing techniques are discussed, including a focus on prosthetic material degradation. New manufacturing approaches and future technological developments are also discussed in the context of specific tissues requiring aesthetic restoration, such as ear, nose, face, eye, breast, and hand. As advanced manufacturing moves from research into clinical practice, prosthetics can begin new age to significantly improve the quality of life for those suffering tissue loss or disfigurement.


Assuntos
Polímeros , Próteses e Implantes , Humanos
13.
Sci Rep ; 10(1): 11453, 2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32651436

RESUMO

Craniofacial prostheses are commonly used to restore aesthetics for those suffering from malformed, damaged, or missing tissue. Traditional fabrication is costly, uncomfortable for the patient, and laborious; involving several hours of hand-crafting by a prosthetist, with the results highly dependent on their skill level. In this paper, we present an advanced manufacturing framework employing three-dimensional scanning, computer-aided design, and computer-aided manufacturing to efficiently fabricate patient-specific ear prostheses. Three-dimensional scans were taken of ears of six participants using a structured light scanner. These were processed using software to model the prostheses and 3-part negative moulds, which were fabricated on a low-cost desktop 3D printer, and cast with silicone to produce ear prostheses. The average cost was approximately $3 for consumables and $116 for 2 h of labour. An injection method with smoothed 3D printed ABS moulds was also developed at a cost of approximately $155 for consumables and labour. This contrasts with traditional hand-crafted prostheses which range from $2,000 to $7,000 and take around 14 to 15 h of labour. This advanced manufacturing framework provides potential for non-invasive, low cost, and high-accuracy alternative to current techniques, is easily translatable to other prostheses, and has potential for further cost reduction.


Assuntos
Desenho Assistido por Computador/economia , Orelha/fisiologia , Auxiliares de Audição/economia , Próteses e Implantes/economia , Humanos , Impressão Tridimensional , Desenho de Prótese/economia , Software
14.
Artigo em Inglês | MEDLINE | ID: mdl-32391336

RESUMO

Each year, congenital defects, trauma or cancer often results in considerable physical disfigurement for many people worldwide. This adversely impacts their psychological, social and economic outlook, leading to poor life experiences and negative health outcomes. In many cases of soft tissue disfigurement, highly personalized prostheses are available to restore both aesthetics and function. As discussed in part A of this review, key to the success of any soft tissue prosthetic is the fundamental properties of the materials. This determines the maximum attainable level of aesthetics, attachment mechanisms, fabrication complexity, cost, and robustness. Since the early-mid 20th century, polymers have completely replaced natural materials in prosthetics, with advances in both material properties and fabrication techniques leading to significantly improved capabilities. In part A, we discussed the history of polymers in prosthetics, their ideal properties, and the application of polymers in prostheses for the ear, nose, eye, breast and finger. We also reviewed the latest developments in advanced manufacturing and 3D printing, including different fabrication technologies and new and upcoming materials. In this review, Part B, we detail the chemistry of the most commonly used synthetic polymers in soft tissue prosthetics; silicone, acrylic resin, vinyl polymer, and polyurethane elastomer. For each polymer, we briefly discuss their history before detailing their chemistry and fabrication processes. We also discuss degradation of the polymer in the context of their application in prosthetics, including time and weathering, the impact of skin secretions, microbial growth and cleaning and disinfecting. Although advanced manufacturing promises new fabrication capabilities using exotic synthetic polymers with programmable material properties, silicones and acrylics remain the most commonly used materials in prosthetics today. As research in this field progresses, development of new variations and fabrication techniques based on these synthetic polymers will lead to even better and more robust soft tissue prosthetics, with improved life-like aesthetics and lower cost manufacturing.

15.
J Cell Biol ; 219(4)2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32328639

RESUMO

Cohesin is essential for genome folding and inheritance. In somatic cells, these functions are both mediated by Scc1-cohesin, which in mitosis is released from chromosomes by Wapl and separase. In mammalian oocytes, cohesion is mediated by Rec8-cohesin. Scc1 is expressed but neither required nor sufficient for cohesion, and its function remains unknown. Likewise, it is unknown whether Wapl regulates one or both cohesin complexes and chromosome segregation in mature oocytes. Here, we show that Wapl is required for accurate meiosis I chromosome segregation, predominantly releases Scc1-cohesin from chromosomes, and promotes production of euploid eggs. Using single-nucleus Hi-C, we found that Scc1 is essential for chromosome organization in oocytes. Increasing Scc1 residence time on chromosomes by Wapl depletion leads to vermicelli formation and intra-loop structures but, unlike in somatic cells, does not increase loop size. We conclude that distinct cohesin complexes generate loops and cohesion in oocytes and propose that the same principle applies to all cell types and species.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Cromossomos de Mamíferos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Oócitos/metabolismo , Proteínas/metabolismo , Animais , Células Cultivadas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Coesinas
16.
Artigo em Inglês | MEDLINE | ID: mdl-32300585

RESUMO

Physical disfigurement due to congenital defects, trauma, or cancer causes considerable distress and physical impairment for millions of people worldwide; impacting their economic, psychological and social wellbeing. Since 3000 B.C., prosthetic devices have been used to address these issues by restoring both aesthetics and utility to those with disfigurement. Internationally, academic and industry researchers are constantly developing new materials and manufacturing techniques to provide higher quality and lower cost prostheses to those people who need them. New advanced technologies including 3D imaging, modeling, and printing are revolutionizing the way prostheses are now made. These new approaches are disrupting the traditional and manual art form of prosthetic production which are laborious and costly and are being replaced by more precise and quantitative processes which enable the rapid, low cost production of patient-specific prostheses. In this two part review, we provide a comprehensive report of past, present and emerging soft-tissue prosthetic materials and manufacturing techniques. In this review, part A, we examine, historically, the ideal properts of a polymeric material when applied in soft-tissue prosthetics. We also detail new research approaches to target specific tissues which commonly require aesthetic restoration (e.g. ear, nose and eyes) and discuss both traditional and advanced fabrication methods, from hand-crafted impression based approaches to advanced manufactured prosthetics. We discuss the chemistry and related details of most significant synthetic polymers used in soft-tissue prosthetics in Part B. As advanced manufacturing transitions from research into practice, the five millennia history of prosthetics enters a new age of economic, personalized, advanced soft tissue prosthetics and with this comes significantly improved quality of life for the people affected by tissue loss.

17.
J Tissue Eng ; 11: 2041731420901621, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32110373

RESUMO

Biomaterial development for clinical applications is currently on the rise. This necessitates adequate in vitro testing, where the structure and composition of biomaterials must be specifically tailored to withstand in situ repair and regeneration responses for a successful clinical outcome. The chorioallantoic membrane of chicken embryos has been previously used to study angiogenesis, a prerequisite for most tissue repair and regeneration. In this study, we report an optimised ex ovo method using a glass-cling film set-up that yields increased embryo survival rates and has an improved protocol for harvesting biomaterials. Furthermore, we used this method to examine the intrinsic angiogenic capacity of a variety of biomaterials categorised as natural, synthetic, natural/synthetic and natural/natural composites with varying porosities. We detected significant differences in biomaterials' angiogenesis with natural polymers and polymers with a high overall porosity showing a greater vascularisation compared to synthetic polymers. Therefore, our proposed ex ovo chorioallantoic membrane method can be effectively used to pre-screen biomaterials intended for clinical application.

18.
J Mech Behav Biomed Mater ; 105: 103695, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32090895

RESUMO

Melt electrowriting (MEW) has grown in popularity in biofabrication research due to its ability to fabricate complex, high-precision networks of fibres. These fibres can mimic the morphology of a natural extracellular matrix, enabling tissue analogues for transplantation or personalised drug screening. To date, MEW has employed two different collector-plate modalities for the fabrication of constructs. Flat collector plates, typical of traditional 3D printing methods, allow for the layer-by-layer fabrication of 2D structures into complex 3D structures. Alternatively, rotating mandrels can be used for the creation of tubular scaffolds. However, unlike other additive manufacturing techniques that can immediately start and stop the extrusion of material during printing, MEW instead requires a continuous flow of polymer. Consequently, conventional g-code control software packages are unsuitable. To overcome this challenge, a suite of customised pattern generation software tools have been developed to enable the design of MEW scaffolds with highly-controlled geometry, including crosshatch, gradient porosity, tubular, and patient-specific configurations. The high level of design control using this approach enables the production of scaffolds with highly adaptable mechanical properties, as well as the potential to influence biological properties for cell attachment and proliferation.


Assuntos
Engenharia Tecidual , Alicerces Teciduais , Matriz Extracelular , Humanos , Porosidade , Impressão Tridimensional
19.
Mol Cell ; 77(4): 825-839.e7, 2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-31837995

RESUMO

In mammals, chromatin organization undergoes drastic reorganization during oocyte development. However, the dynamics of three-dimensional chromatin structure in this process is poorly characterized. Using low-input Hi-C (genome-wide chromatin conformation capture), we found that a unique chromatin organization gradually appears during mouse oocyte growth. Oocytes at late stages show self-interacting, cohesin-independent compartmental domains marked by H3K27me3, therefore termed Polycomb-associating domains (PADs). PADs and inter-PAD (iPAD) regions form compartment-like structures with strong inter-domain interactions among nearby PADs. PADs disassemble upon meiotic resumption from diplotene arrest but briefly reappear on the maternal genome after fertilization. Upon maternal depletion of Eed, PADs are largely intact in oocytes, but their reestablishment after fertilization is compromised. By contrast, depletion of Polycomb repressive complex 1 (PRC1) proteins attenuates PADs in oocytes, which is associated with substantial gene de-repression in PADs. These data reveal a critical role of Polycomb in regulating chromatin architecture during mammalian oocyte growth and early development.


Assuntos
Cromatina/química , Oócitos/crescimento & desenvolvimento , Oogênese/genética , Proteínas do Grupo Polycomb/fisiologia , Animais , Blastocisto/química , Proteínas de Ciclo Celular/fisiologia , Proteínas Cromossômicas não Histona/fisiologia , Embrião de Mamíferos/química , Inativação Gênica , Código das Histonas , Camundongos , Oócitos/química , Transcrição Gênica , Coesinas
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