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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Samband mellan nukleära avvikelser i tvåcellsstadiet hos embryon efter assisterad befruktning och chans till graviditet och levande fött barn / Association between nuclear errors in the two- cell stage of embryos after assisted fertilization and chances of pregnancy and live birth

Sadullah, Helbeen January 2023 (has links)
Bakgrund Assisterad befruktning är en vanlig behandling för infertilitet, vilket innebär oförmågan att bli gravid. Vid assisterad befruktning övervakas embryoutvecklingen med hjälp av Time Lapse Imaging-teknologi i en EmbryoScope och implantationsförmågan bedöms. Tidigare forskning har identifierat nukleära avvikelser (NE) i tidig embryoutveckling som kan påverka graviditetsfrekvensen (Pregnancy Rate, PR) och frekvensen av levande födda barn (live birth rate, LBR). Idag beräknas NE till fyra fenotyper (NEP): binukleation, mikronukleation, multinukleation samt splittrad nukleation.   Syfte Syftet med denna retrospektiva registerstudie var att undersöka sambandet mellan NE under tidig embryoutveckling och PR, LBR samt missfall för att förbättra embryoselektionen vid Reproduktionsmedicinskt centrum (RMC) på Örebro universitetssjukhus (USÖ).   Resultat Resultatet visade att 37,5% av de återförda blastocysterna i studien hade NE, och att PR och LBR påverkades av vilken NEP embryot hade. Embryon med binukleäritet hade högre PR och LBR än embryon med övriga kärnstatusar. KIDScore D5 visade sig vara ett bra selektionsverktyg för blastocyster återförda dag 5, men närvaron/frånvaron av NE påverkade kopplingen mellan KIDScore D5 och graviditet/barn på ett oväntat sätt, beroende på NEP.   Slutsats Embryoselektionen vid RMC på USÖ kan förbättras genom att ta hänsyn till kärnstatusen i tidig embryoutveckling, men en större studiepopulation behövs för att bekräfta korrelationen mellan alla variabler. / Background Assisted reproduction is a common treatment for infertility, which is the inability to become pregnant. In assisted reproduction, the development of embryos is monitored using Time Lapse Imaging technology in an EmbryoScope, and the implantation potential is assessed. Previous research has identified nuclear errors (NE) in early embryonic development that can affect pregnancy rates (PR) and live birth rates (LBR). NE is currently divided into four phenotypes (NEP): binucleation, micronucleation, multinucleation, and fragmented nucleation.   Objective The purpose of this retrospective registry study was to investigate the correlation between NE in early embryonic development and PR, LBR, and miscarriage to improve embryo selection at the Reproductive Medicine Center (RMC) at Örebro University Hospital (USÖ).   Results The results showed that 37.5% of the returned blastocysts in the study had NE, and that PR and LBR were affected by the NEP of the embryo. Embryos with binucleation had higher PR and LBR than embryos with other nuclear statuses. KIDScore D5 was found to be a good selection tool for blastocysts returned on day 5, but the presence/absence of NE affected the correlation between KIDScore D5 and pregnancy/childbirth in an unexpected way, depending on the NEP.   Conclusion Embryo selection at RMC at USÖ can be improved by considering the nuclear status in early embryonic development, but a larger study population is needed to confirm the correlation between all variables.
2

Multifunctional 4D-Printed Sperm-Hybrid Microcarriers for Biomedical Applications

Rajabasadi, Fatemeh 10 April 2024 (has links)
The field of biomedical sciences has been expanded through the introduction of a novel cohort of soft and intelligent microrobots that can be remotely operated and controlled through the use of external stimuli, such as ultrasound, magnetic fields, or electric fields, or internal stimuli, such as chemotaxis. The distinguishing factor of these microrobots lies in their propulsion system, which may encompass chemical, physical, or biohybrid mechanisms. Particularly, microrobots propelled by motile cells or microorganisms have found extensive usage because they combine the control/steerability and image-enhancement capabilities of the synthetic microstructures with the taxis and cell-interaction capabilities of the biological components. Spermatozoa (sperms), among other types of motile microorganisms and cells, are promising biological materials for building biohybrid microrobots because they are inherently designed to swim through complex fluids and organs, like those in the reproductive system, without triggering negative immune responses. Sperms are suitable for a variety of gynecological healthcare applications due to their drug encapsulating capability and high drug-carrying stability, in addition to their natural role of fertilization. One objective of this project is to help sperms reach the site of fertilization in vivo where the sperm count is low (20 million sperm per mL), a condition known as oligospermia. In order to reach this goal, we are developing alternative strategies for transporting a significant number of sperms, as well as improving the functionality of sperm-hybrid microcarriers. Here, we use a thermoresponsive hydrogel made of poly(N-isopropylacrylamide) (PNIPAM) and a non-stimuli-responsive polymer (IPS photoresist) to create four dimensional (4D)-printed sperm-hybrid microcarriers via two-photon polymerization (TPP). We present a multifunctional microcarrier that can: i) transport and deliver multiple motile sperms to increase the likelihood of fertilization, ii) capacitate/hyperactivate the sperms in situ through the local release of heparin, and iii) assist the degradation of the hyaluronic acid (HA), present in extracellular matrix (ECM) of oocyte-cumulus surrounded the Egg. HA degradation occurs through the local action of hyaluronidase-loaded polymersomes (HYAL-Psomes) that have been immobilized on the microcarrier's surface. Dual ultrasonic (US)/photoacoustic (PA) imaging technology can also be used to visualize a swarm of microcarriers, making them ideal candidates for upcoming in vivo applications. In addition, as a second objective, we demonstrate that similar sperm-hybrid microcarriers can be utilized to deliver targeted enzymes and medication for the treatment of gynecological cancer. As proof of concept, we show that combined therapy using enzymes and anti-cancer drugs is an appealing strategy for disrupting the tumor tissue microenvironment and inducing cell apoptosis, thereby offering a more effective cancer therapy. To achieve this, we functionalize the microcarriers with polymersomes loaded with enzymes (such as hyaluronidase and collagenase) and anti-cancer drugs (such as curcumin), respectively, and demonstrate their cargo-release capability, enzyme function, and therapeutic effect for targeting cervical cancer cells in vitro.:Abstract iv 1 Introduction 1 1.1 Motivation 1 1.2 Objectives 3 1.3 Structure of this dissertation 4 2 Background 5 2.1 Introduction on additive manufacturing technology 5 2.2 Direct laser writing (DLW) based on two-photon polymerization 6 2.2.1 Writing principles of two-photon lithography 8 2.2.2 Available materials for two-photon lithography 9 2.2.3 Engineering (Preprogrammed designs) 12 2.3 4D Lithography 13 2.3.1 Biodegradable microrobot 13 2.3.2 Stimuli-responsive micromotors 15 2.3.3 Other 4D-printing approaches 17 2.4 Motion at the microscale (Micromotility) 21 2.4.1 Physical propelled micromotors 23 2.4.2 Chemical propelled micromotors 32 2.4.3 Biohybrid micromotors 34 2.5 Other two-photon polymerized microrobots and their biomedical applications 35 2.5.1 Functionalized carriers 36 2.5.2 Multiple-cell carrying scaffolds 38 2.5.3 Single particle and cell transporters 39 2.6 Comparison of 3D and 4D-lithography with other fabrication methods 42 3 Materials and methods 44 3.1 Synthesis and fabrication 44 3.1.1 Synthesis of PNIPAM 44 3.1.2 Fabrication of microcarrier 44 3.1.3 Preparation of sperm medium and sperm solution 45 3.1.4 Preparation and composition of different body fluids 45 3.1.5 Fluidics channels 46 3.1.6 In situ preparation of microcarriers and sperms 46 3.1.7 Loading of microcarriers with heparin 46 3.1.8 Synthesis of block copolymers (BCPs) 47 3.1.9 Fabrication of Empty-Psomes A and D 48 3.1.10 Preparation of Curcumin complex CU(βCD)2 and calibration curve 49 3.1.11 Fabrication of cargo-loaded Psomes with enzymes and antitumoral drug 50 3.2 Characterization 51 3.2.1 MTS-Assay 51 3.2.2 Toluidine blue assay 52 3.2.3 Characterization of Empty-Psomes A and D: pH cycles and pH titration by dynamic light scattering (DLS) 53 3.2.4 Characterization of cargo-loaded Psomes with enzymes and antitumoral drug 54 3.2.5 Loading efficiency of HYAL-Psomes 55 3.2.6 Loading efficiency of MMPsomes 56 3.2.7 Loading efficiency, stability and release study of CU(βCD)2-Psomes 57 3.2.8 Size and polydispersity analysis of cargo-loaded Psomes in different simulated body fluids by DLS 58 3.2.9 Conformation and stability study of cargo-loaded Psomes in different simulated body fluids by asymmetric flow field flow fractionation (AF4) 59 3.2.10 Immobilization of the cargo-loaded Psomes on the surfaces 61 3.2.11 Enzymatic assay of HYAL for enzyme activity measurement 62 3.2.12 Enzymes assay in different simulated body fluids 64 3.2.13 Stability study of RhB-HYAL-Psomes in different pH 65 3.2.14 Calculation of the magnetic field flux of an external hand-held magnet 66 3.3 Temperature actuation and imaging 67 3.3.1 Temperature actuation test of PNIPAM and video recording 67 3.3.2 Hybrid ultrasound (US) and photoacoustic (PA) Imaging 67 3.4 Other useful information 68 3.4.1 pH and temperature through the female reproductive tract 68 3.4.2 Calculation of the light-to-heat conversion during imaging process 69 4 Multifunctional 4D-printed sperm-hybrid microcarriers for assisted reproduction 72 4.1 Background 72 4.2 Concept and fabrication of the 4D-printed microcarriers 74 4.3 Sperm coupling and geometrical optimization of microcarrier 77 4.4 Characterization of the 4D-printed streamlined microcarriers 78 4.5 Microcarrier loaded with heparin for in situ sperm capacitation 82 4.6 Microcarriers decorated with HYAL-Psomes for in situ degradation of the HA-cumulus complex 86 4.6.1 Immobilization of HYAL-Psomes on the microcarrier’s surface 89 4.6.2 Qualitative study of cumulus cell removal 90 4.7 Sperm-microcarrier motion performance in oviduct-mimicking fluids 91 4.7.1 Capture, transport, and release of sperms 92 4.7.2 Sperm-microcarrier motion performance on ex vivo oviduct tissue 93 4.8 Tracking of a swarm of microcarriers with a dual ultrasound (US) and photoacoustic (PA) imaging system 95 4.9 Summary 96 5 Polymersomes-decorated micromotors with multiple cargos for gynecological cancer therapy 98 5.1 Background 98 5.2 Characterization and size quantification of Psomes before and after loading of cargoes by DLS, and Cryo-TEM 103 5.3 Characterization and size quantification of cargo-loaded Psomes by DLS, and Cryo-TEM in different simulated bodily fluids 104 5.4 Immobilization and characterization of cargo-loaded Psomes on the microcarrier’s surface 106 5.5 Immobilization and characterization of dual cargo-loaded Psomes on the microcarrier’s surface 108 5.6 Investigation of ECM degradation and antitumoral effect of cargo-loaded Psomes 110 5.7 Magnetic and bio-hybrid guidance of microcarriers toward targeted cargo delivery 115 5.8 Summary 117 6 Conclusion and Outlook 119 6.1 Achievements 119 6.2 Outlook 121 Bibliography I List of Figures and Tables XXI Acknowledgements and funding XXIV Scientific publications and contributions XXVI Curriculum Vitae XXVII
3

Recepção de oócitos: estudo retrospectivo para análise da técnica

Vicensoto, Wagner 01 June 2004 (has links)
Made available in DSpace on 2016-01-26T12:51:34Z (GMT). No. of bitstreams: 1 wagnervicensoto_dissert_parte1.pdf: 574820 bytes, checksum: 52b81a5827b47b0dd96036bb137bd216 (MD5) Previous issue date: 2004-06-01 / The oocyte donation and reception program is a technique in which female gametes from a woman (donor) are donated to other woman (recipient) in order to be fertilized with the respective recipient s husband spermatozoa. The present study analyzed fourteen patients who underwent 21 cycles of egg reception by this assisted reproductive medical technique at the Reproductive Medicine Institute (RMI) of São José do Rio Preto-SP, in the period from January 1998 to December 2002. The recipients age ranged between 29 to 49 years; the mean age 40 years. Ten patients (71.5%) did not report previous gestation, therefore considered women with primary infertility. In order to perform the indications to the oocyte reception we classified five patients (35.7%) as having premature menopause, five (35.7%) as ovarian failure, three (21.5%) as physiological menopause, and one (7.1%) as unsuccessful responder to previous treatments. Only six patients (42.9%) had not undergone previous infertility treatments. In 92.9% of the patients, the assisted reproductive technique used was the Intracytoplasmic Sperm Injection (ICSI). The number of embryos transferred per cycle was between two and four. A total of 21 cycles were performed with a rate of 52.4% of gestation per cycle and 71.5% gestation per patient. The rate of multiple gestations was 27.3%. Regarding the gestation evolutions, it was observed a rate of 36.4% of miscarriage and 63.6% of ongoing pregnancies, in which 9.1% had premature delivery, and 54.5% had full term delivery without intercurrences. The rate of home baby was 50%. The oocyte donation and reception program showed to be a successful technique, with excellent results, providing a feasible and ethic way of getting pregnant some selected patients who have otherwise been considered as having an infertility reserved diagnostic. / O programa de doação-recepção de oócítos é técnica pela qual os gametas femininos (oócitos) de uma mulher (doadora) são doados a outra (receptora) para que sejam fertilizados com espermatozóides dos respectivos maridos. Este estudo analisou quatorze pacientes submetidas a 21 ciclos de ovorecepção por técnica de reprodução medicamente assistida no Instituto de Medicina Reprodutiva (IMR) de São José do Rio Preto-SP, no período de janeiro de 1998 a dezembro de 2002. A idade das pacientes receptoras variou de 29 a 49 anos com média de 40 anos. Dez (71,5%) pacientes não referiram gestação anterior, sendo consideradas como infertilidade primária. Como indicações para realização de recepção de oócitos classificamos cinco (35,7%) pacientes como menopausa precoce, cinco (35,7%) como falência ovaríana, três (21,5%) como menopausa fisiológica e uma (7,1 %) como má respondedora. Apenas seis (42,9%) pacientes não haviam sido submetidas a tratamento anterior para infertilidade. Em 92,9% das pacientes foi utilizado a injeção intra-citoplasmática de espermatozóide (lCSl) como técnica de fertilização assistida. Foram transferidos por ciclo entre dois e quatro embriões. Dos 21 ciclos realizados obteve-se taxa de 52,4% de gestação por ciclo e de 71,5% de gestação por paciente. A taxa de gestação múltipla foi de 27,3%. Em relação à evolução das gestações observou-se taxa de abortamento de 36,4% e evolução da gestações em 63,6%, com 9,1% de parto prematuro e 54,5% gestações a termo sem íntercorrêncías. A taxa de "bebê em casa" foi de 50%. O programa de doação-recepção de oócitos mostrou-se técnica de excelentes resultados, representando uma forma viável e ética de se obter gestação em pacientes selecionadas que antes tinham diagnóstico reservado de infertilidade.

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