Micromanipulation is considered a challenging task which requires high precision motion and measurement at the micro scale. When micromanipulation is concerned with living organisms important considerations need to be addressed. These include the physical or chemical properties of micro-organisms, living conditions, responses to the environment and achieving suitably delicate manipulation. Bio-micromanipulation can include micro surgery or cell injection operations, or to determine interaction forces as the basis to investigate behavior and properties of living micro-organisms. In order to achieve suitable bio-micromanipulation appropriate processes and/or sensory systems need to be investigated. This thesis aims to look into the force interaction and sensing addressing two distinctive challenges in the field of bio-micromanipulation. To this end, this thesis presents two major contributions to advancing bio-micromanipulation. Firstly, a novel Haptic Microrobotic Cell Injection System is introduced which is able to assist a bio-operator through haptic interaction. The system introduces a mapping framework which provides an intuitive method for the bio-operator to maneuver the micropipette in a manner similar to handheld needle insertion. To accurately control the microrobot, a neuro-fuzzy modeling and control scheme has been developed. Volumetric, axial and planar haptic virtual fixtures are introduced to guide the bio-operator during cell injection. Aside from improving real-time operator performance using the physical system, the system is novel in facilitating virtual offline operator training. Secondly, a first-of-its-kind micro-pillar based on-chip system for dynamic force measurement of C. elegans motion is introduced. The system comprises a microfabricated PDMS device to direct C. elegans into a matrix of micropillars within a channel mimicking its dwelling environment. An image processing algorithm is able to track the interaction of the C. elegans with the pillars and estimate contact forces based on micropillar deflections. The developed micropillar system is capable of measuring the force with sub-micron resolution while providing a continuous force output spectrum.

Cancer study and drug selection research attract more and more researchers, which need a significant laboratory technique, named cell injection. Hundreds of cells are loaded on devices and injected to investigate the behavior of the cells. Traditionally, cell injection is performed manually, which leads to human fatigue, is time-consuming and has a low success rate. Therefore, a system which can replicate the actions of what technicians do, such as to aspirate cells, transfer cells, immobilize cells, and release cells automatically, is needed. This system must be accurate, reliable, and efficient and operate without human intervention. A cell-transfer-cover and a cell-holder have been fabricated and a cell injection system has been set up to investigate the performance of the newly created device. Simulations and experiments have proven that this system would carry out the entire process of cell injection with the result of enhancing the speed of this important activity.

Cancer study and drug selection research attract more and more researchers, which need a significant laboratory technique, named cell injection. Hundreds of cells are loaded on devices and injected to investigate the behavior of the cells. Traditionally, cell injection is performed manually, which leads to human fatigue, is time-consuming and has a low success rate. Therefore, a system which can replicate the actions of what technicians do, such as to aspirate cells, transfer cells, immobilize cells, and release cells automatically, is needed. This system must be accurate, reliable, and efficient and operate without human intervention. A cell-transfer-cover and a cell-holder have been fabricated and a cell injection system has been set up to investigate the performance of the newly created device. Simulations and experiments have proven that this system would carry out the entire process of cell injection with the result of enhancing the speed of this important activity.

Introduction : Malgré leur état non-prolifératif in vivo, les cellules endothéliales cornéennes (CEC) peuvent être amplifiées in vitro. Leur transplantation subséquente par injection intracamérale pourrait surmonter la pénurie de tissus associée à l’allo-greffe traditionnelle – l’unique traitement définitif disponible pour les endothéliopathies cornéennes. Objectif : Évaluer la fonctionnalité d’un endothélium cornéen reconstitué par injection de CEC dans la chambre antérieure du félin. Méthodes : Les yeux droits de 16 animaux ont été opérés. Huit ont été désendothélialisés centralement avec injection de 2x10e5 (n=4) ou 1x10e6 (n=4) CEC félines supplémentées avec Y-27632 et marquées avec SP-DiOC18(3). Deux ont été désendothélialisés complètement et injectés avec 1x10e6 CEC et Y-27632. Six contrôles ont été désendothélialisés centralement (n=3) ou complètement (n=3) et injectés avec Y-27632 sans CEC. La performance clinique, l’intégrité anatomique, le phénotype fonctionnel et l’expression de SP-DiOC18(3) du nouvel endothélium ont été étudiés. Résultats : Les cornées greffées avec 2x10e5 CEC et les contrôles désendothélialisés centralement ont réussi le mieux cliniquement. Les contrôles désendothélialisés complètement sont restés opaques. L’histopathologie a révélé une monocouche endothéliale fonctionnelle dans les cornées greffées avec 2x10e5 CEC et les contrôles désendothélialisés centralement, une multicouche endothéliale non-fonctionnelle dans les cornées désendothélialisées centralement et greffées avec 1x10e6 CEC, et un endothélium fibrotique non-fonctionnel dans les cornées désendothélialisées complètement. L’expression de SP-DiOC18(3) était rare dans les greffes. Conclusion : La thérapie par injection cellulaire a reconstitué un endothélium partiellement fonctionnel, auquel les CEC injectées n’ont contribué que peu. L’injection de Y-27632 sans CEC a reconstitué l’endothélium le plus sain. Des études additionnelles investiguant l’effet thérapeutique de Y-27632 seul sont justifiées. / Introduction : Despite their growth arrest in vivo, corneal endothelial cells (CEC) can be amplified in vitro. Their subsequent transplantation by cell-injection therapy could overcome the tissue scarcity associated with traditional allo-transplantation, which is the only currently available treatment for irreversible corneal endothelial failure. Objective : To evaluate the functionality of a corneal endothelium reconstituted by cell- injection therapy in the feline. Methods: The right eyes of 16 animals underwent surgery. Eight underwent central endothelial scraping and injection with 2x10e5 (n=4) or 1x10e6 (n=4) feline CEC supplemented with Y-27632 and labeled with SP-DiOC18(3). After total scraping, two eyes were injected with 1x10e6 labeled CEC and Y-27632. The central (n=3) or entire (n=3) endothelium was scraped in six controls followed by Y-27632 injection without CEC. Outcomes included clinical performance, anatomical integrity, functional phenotype and SP-DiOC18(3) expression of the new endothelium. Results: Corneas grafted with 2x10e5 CEC and centrally scraped controls performed the best clinically. Entirely scraped controls remained hazy and thick. Histopathology revealed a confluent, functional endothelial monolayer in corneas grafted with 2x10e5 CEC and centrally scraped controls, a non-uniform, non-functional endothelial multilayer in centrally scraped corneas grafted with 1x10e6 CEC, and a non-functional fibrotic endothelium in entirely scraped grafts and controls. SP-DiOC18(3) was scarce in grafts and absent in controls. Conclusion : Cell-injection therapy reconstituted an incompletely functional endothelium, to which injected CEC contributed little. Y-27632 injection without CEC reconstituted the healthiest endothelium. Further studies investigating the therapeutic effect of Y-27632 alone are warranted.

Micro (mi)RNAs have recently been found to play an important role in cancer biology. In order to further understand how miRNAs affect prostate tumour progression, we evaluated miRNA expression in two invasive prostate tumour lines, PC3 and DU145. We then focused our evaluation on a novel miRNA, miR-105, whose levels were significantly decreased in both tumour cell lines as compared to normal prostate epithelial cells. As miR-105 levels were reduced in prostate tumour cell lines, we restored its expression following transfection of cells with mimic constructs to over-express miR-105 in both cell lines, in order to determine its effect on various tumourigenic properties. Over-expression caused decreased tumour cell proliferation, anchorage-independent growth and invasion in vitro and inhibited tumour growth in vivo. We further identified CDK6 as a putative target of miR-105, which likely contributed to its inhibition of tumour cell growth. Our results suggest that miR-105 inhibits tumour cell proliferation and may be an interesting target to regulate tumour growth or potentially used as a biomarker to differentiate between less and more aggressive tumours in patients.

Micro (mi)RNAs have recently been found to play an important role in cancer biology. In order to further understand how miRNAs affect prostate tumour progression, we evaluated miRNA expression in two invasive prostate tumour lines, PC3 and DU145. We then focused our evaluation on a novel miRNA, miR-105, whose levels were significantly decreased in both tumour cell lines as compared to normal prostate epithelial cells. As miR-105 levels were reduced in prostate tumour cell lines, we restored its expression following transfection of cells with mimic constructs to over-express miR-105 in both cell lines, in order to determine its effect on various tumourigenic properties. Over-expression caused decreased tumour cell proliferation, anchorage-independent growth and invasion in vitro and inhibited tumour growth in vivo. We further identified CDK6 as a putative target of miR-105, which likely contributed to its inhibition of tumour cell growth. Our results suggest that miR-105 inhibits tumour cell proliferation and may be an interesting target to regulate tumour growth or potentially used as a biomarker to differentiate between less and more aggressive tumours in patients.

Micro (mi)RNAs have recently been found to play an important role in cancer biology. In order to further understand how miRNAs affect prostate tumour progression, we evaluated miRNA expression in two invasive prostate tumour lines, PC3 and DU145. We then focused our evaluation on a novel miRNA, miR-105, whose levels were significantly decreased in both tumour cell lines as compared to normal prostate epithelial cells. As miR-105 levels were reduced in prostate tumour cell lines, we restored its expression following transfection of cells with mimic constructs to over-express miR-105 in both cell lines, in order to determine its effect on various tumourigenic properties. Over-expression caused decreased tumour cell proliferation, anchorage-independent growth and invasion in vitro and inhibited tumour growth in vivo. We further identified CDK6 as a putative target of miR-105, which likely contributed to its inhibition of tumour cell growth. Our results suggest that miR-105 inhibits tumour cell proliferation and may be an interesting target to regulate tumour growth or potentially used as a biomarker to differentiate between less and more aggressive tumours in patients.