Biocompatible Micro Implant Technologies Using Different Modification And Micro Manufacturing Techniques
Dr. Erdrin Azemi
Date: Thursday, March 3, 2011
Place: EA 409
The first part of the seminar will be on neural interface technologies that link the nervous system and the outside world by either stimulating or recording from neural tissue. These micro technologies show great promise for patients suffering from various neurological injuries or disorders. However, the poor recording stability and longevity of neural interface devices (neural probes) is an imminent obstacle to their advance in widespread clinical applications. The dominant factor that affects chronic neural recordings has been reported to be the inflammatory tissue response including neuronal loss and gliosis around the electrode/tissue interface. We proposed modifying the surface of neural probes with the neural adhesion molecule L1. The L1 molecule is known to specifically promote neurite outgrowth and neuronal survival. We discovered that surface immobilization of L1, introduced a neuron friendly environment by maintaining healthy neuronal density and promoting neurite outgrowth around the recording electrodes. Consequently, reduced gliosis formation was also observed.
The second part of the seminar will be on polymers which are widely researched and applied in the medical field due to their favorable material properties. The field of polymer-composed micro systems is expected to boost as their application demand increases. Innovative ways to micro manufacture polymers have since become available. In our lab we are working on mechanical micromachining as a novel method for fabricating polymer micro needles. The flexible process of computer numerical control (CNC) milling allows for producing microstructures with precise replication and without polymer degradation from extensive heat or UV radiation. We chose the biodegradable poly(lactic-co-glycolic acid) (PLGA) and the biocompatible poly(methyl methacrylate) (PMMA) to show the feasibility of the proposed fabrication method. Arrays of PLGA and PMMA micro needles were fabricated. PLGA needles offer promise as minimally invasive devices for controlled drug delivery in different tissues in the body. We also plan to use the PMMA polymer to manufacture micro-fluidic lab-on-a-chip (LOC) technologies that can be utilized in different sensor and monitoring applications. Technical challenges due to small size and additional phenomena arising from the size-effect are studied. Experiments are performed on the cutting edge micromanufacturing equipments in the Advanced Microsystem Technologies Laboratory (AMT-Lab) at Bilkent University.