Delivery of biologically relevant ions such as drugs, neurotransmitters and hormones have been recognized as powerful a tool to control physiology of animals and plants for research purposes and practical applications. In the plant research community, ions are most commonly delivered as part of a solvent by soaking, spraying, pipetting or by adding to the soil. These methods have low control of the delivery dynamics and quantity of ion uptake. These issues motivated the development of the Organic Electronic Ion Pump (OEIP), which delivers only ions of interest by applying an external electric field through a polyelectrolyte membrane of high fixed charge concentration. A miniaturized, implantable version of the OEIP based on capillary fibres (c-OEIP), where the polyelectrolyte is enclosed in a capillary, enabled even higher precision of the delivery. In this master thesis, c-OEIP has been applied in the tropical plant Kalanchoe Blossfeldiana, chosen due to its characteristic skill to gradually learn to save water: while maturing it shifts to night time photosynthesis and transpiration, called Constitutive Crassulacean Acid Metabolism. A better understanding of this metabolism and water saving ability could guide engineering of enhanced drought tolerance in crop plants, which is motivated by the increasing global warming. One of the biologically relevant ions that is potentially involved in this water-saving learning process is the malate ions. The aim of this thesis is to test the hypothesis that c-OEIP is able to deliver malate ions to cause a reduction in stomatal conductance and transpiration of intact leaves of Kalanchoe Blossfeldiana. To test this hypothesis, firstly, the capillary-based OEIP were fabricated using polyimide coated glass capillaries filled with AETMAC polyelectrolyte. The ability of these devices to deliver malic acid (MA) was verified by using current-voltage characterisation during loading and delivery of MA. Secondly, the setup for MA delivery with c-OEIP to intact kalanchoe leaf was developed, optimising the insertion method to minimize the wounding of the plant and increase assay reproducibility. Finally, the MA was delivered to intact kalanchoe leaves via c-OEIP, where the plant transpiration response was evaluated using standard gas exchange porometer and also novel infrared camera, as plant temperature can be correlated with plant transpiration status. The results indicate that c-OEIP can deliver MA and trigger reduction of transpiration of young kalanchoe leaves, supporting the hypothesis that malate ions act to reduce stomatal conductance, potentially conveying a feedback message from the mesophyll to the guard cells. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2019-03-25T11:56:58Z No. of bitstreams: 1 Jeferson Cardoso do Rosario_.pdf: 3523684 bytes, checksum: 6d033c623e7ef74a93692efd6ca37e8e (MD5) / Made available in DSpace on 2019-03-25T11:56:58Z (GMT). No. of bitstreams: 1 Jeferson Cardoso do Rosario_.pdf: 3523684 bytes, checksum: 6d033c623e7ef74a93692efd6ca37e8e (MD5) Previous issue date: 2019-01-18 / Nenhuma / O traumatismo cranioencefálico (TCE) é atualmente a terceira maior causa de óbitos no âmbito mundial. Estudos recentes têm demonstrado que a monitorização de pressão intracraniana (PIC), como forma de cálculo da pressão de perfusão cerebral (PPC) é uma ferramenta importante para avaliação do fluxo sanguíneo cerebral (FSC), provocando sensível redução nas taxas de mortalidade. Além do TCE, outras patologias ou situações neurocirúrgicas tem utilizado a técnica de monitorização de PIC. A monitorização desse parâmetro foi proposta já na década de 50, onde um tubo com fluido em contato com o líquido cefalorraquidiano (LCR) era introduzido no espaço intracraniano e conectado a um transdutor de pressão externo. Com a evolução da indústria microeletrônica e dos sistemas microeletromecânicos, foi possível colocar os transdutores na ponta do cateter, permitindo uma monitorização menos invasiva, com menos riscos de infecções. Os cateteres atuais com micro transdutor na ponta podem ser divididos em três grupo: straingauge, fibra óptica e pneumático. Cada grupo possui suas características, entretanto o primeiro tem se demonstrado como solução mais robusta e confiável, com boa relação custo benefício. No presente trabalho foi proposto o desenvolvimento de um cateter implantável de monitorização de pressão intracraniana do tipo micro transdutor strain-gauge. Foram construídos protótipos funcionais e submetidos a ensaios de desempenho, especificados em norma técnica para monitorização de pressão sanguínea, a influência da temperatura na medição de pressão, bem como a exatidão das medições. Os processos empregados no trabalho são utilizados comumente na indústria de encapsulamento de semicondutores, porém foram levadas em consideração as especificidades da aplicação, adequando as técnicas disponíveis às geometrias e materiais empregados, considerando a necessidade de utilização de materiais biocompatíveis. / The traumatic brain injury (TBI) is nowadays the third cause of death in the world. Recent studies have shown the intracranial pressure (ICP) monitoring as an important tool for cerebral perfusion pressure (CPP) calculation and cerebral blood flow (CBF) assestment, reducing significantly the mortality statistics. Besides TBI, several others pathologies and neurosurgery conditions have been using the ICP monitoring technique. The proposal of ICP monitoring first appeared on the 50’s, where a tube fulfilled with fluid in contact with cerebrospinal fluid (CSF) was introduced into the intracranial space and connected to an external pressure transducer. With the waves of the microelectronics and microelectromechanical systems (MEMS) industry evolution, it was possible to put the transducer and all the electronics inside the catheter tip, allowing a less invasive monitoring, decreasing the risk of infection. The state of art catheters with micro transducer on the tip can be divided into three groups: strain-gauge, optical fiber and pneumatic. Each group has it’s own characteristics, however the first has been demonstrated as the rugged solution, being reliable, cost effective and with good accuracy. In the present work, it was proposed the development of an strain-gauge micro transducer implantable catheter for intracranial pressure monitoring. Functional prototypes were built and submitted to performance tests, according to the technical standards in the medical equipment area, the temperature influence over the pressure measurements was evaluated, as well as the accuracy. The adopted processes are commonly used in the semiconductor packaging industry, however it was considered the application special requirements, adapting the processes to the geometry and materials used, considering the needs of biocompatible materials.