Investigating Cell Adhesion to Polymers for Medical Implant Technology

Abstract:

Implantable medical devices (IMDs) have been developed as treatments for disease and to repair injuries or tissue degradation. Risks associated with this technology include complications and infection from implantation surgery. In addition to these risks, which are similar for most surgeries, IMDs have other specific risks such as device rejection due to bio-incompatibility or device failure. Researching materials that are currently used in IMDs, and potential materials for future use, can help to improve designs appropriate for biocompatibility and mitigate these specific risks. Several biomaterials are commonly used to produce IMDs, including organic materials, ceramics, metals, and plastics. Recent attention has been given to the dynamic possibilities of thermoplastics like polylactic acid (PLA), a biocompatible polyester. There are many topological and morphological variations possible in polymer formation, defined by the proportionality of crystalline and amorphous structures within the material. We do not yet clearly know how these differences in topology may affect cellular attachment and appropriateness for IMDs. Our study will build understanding of tissue cell interactions with thermoplastic polymers by investigating adhesion of fibroblasts from the NIH 3T3 cell lineage onto substrates of PLA engineered to exhibit various degrees of crystalline and amorphous character. The level of adhesion will be initially assessed by analyzing western blots targeting expression of the cellular attachment proteins integrin Α2 and Α5. Detecting characteristics that promote cell adhesion will enable us to refine the targeting of materials for future investigation. Our study aims to further pursue other topological variables induced by shearing, etching, and manipulating the surface chemistry of PLA substrates then examining the effect these treatments have on fibroblast proliferation and morphology by direct imaging via stereo-fluorescent microscopy.