OXYGEN DELIVERY BY OUTGASSING OF HYPERBARICALLY LOADED MICROTANKS AND BULK POLYMERS FOR BIOMEDICAL APPLICATIONS

OXYGEN;OXYGEN DELIVERY;OUTGASSING;HYPERBARIC;MICROTANKS;BIOMEDICAL;TISSUE ENGINEERING;GRAFT;HYPOXIA;ANOXIA;DIFFUSION LIMITATIONS;Biomedical Engineering

Cook, Colin AGrayson, Warren L ;

Johns Hopkins University

关键词: OXYGEN;    OXYGEN DELIVERY;    OUTGASSING;    HYPERBARIC;    MICROTANKS;    BIOMEDICAL;    TISSUE ENGINEERING;    GRAFT;    HYPOXIA;    ANOXIA;    DIFFUSION LIMITATIONS;    Biomedical Engineering;   

Others  :  https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/60330/COOK-THESIS-2014.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: JOHNS HOPKINS DSpace Repository

【 摘 要 】

Oxygen diffusion limitations within nascent tissue engineering scaffolds leads to the development of hypoxic regions, cell death, and graft failure. Diffusion limitations are most severe in scaling from the mm-sized grafts studied in rodents to the cm-sized grafts required for human patients and thus represent a major barrier to clinical translation. Extensive efforts have been made to delivery oxygen within tissue engineering scaffolds to help maintain cell viability during the period of vascular development and anastomosis. Unfortunately, the approaches that have been developed which include peroxide-doping, perfluorocarbons, hyperbaric oxygen therapy have lacked cytocompatability, oxygen capacity, and practicality, respectively. The outgassing of oxygen from hyperbarically loaded polymers represents a novel and elegant solution that addresses these shortcomings. Many commonly used biocompatible polymers possess high resistance to oxygen diffusion but a non-trivial solubility of oxygen (on the order of 10% V/V/atm). Thus it is possible to load the polymer with oxygen gas using a hyperbaric chamber and to subsequently achieve a prolonged delivery of oxygen as the polymer outgasses. By forming microscopic polymeric shells with a hollow core, the loading efficiency of oxygen can be greatly enhanced and such a structure is termed a microtank. In this thesis, we will describe the development and empirical validation of the theory governing the oxygen delivery from hyperbarically loaded materials, including microtanks. Oxygen loaded microtanks and/or bulk polymers can be combined with a hydrogel phase to form a scaffold with oxygen delivery throughout. This oxygen delivery approach has been shown to enhance the survival of human cells cultured under anoxic conditions for out to 6 days. Beyond tissue engineering, hyperbaric oxygen loading could be used to functionalize many clinically used polymer implants such as screws, suture anchors, stiches, etc. as elevated local oxygen tensions have been shown to enhance collagen deposition and reduce infection. Indeed, the biomedical applications are diverse and abundant.