| 摘要 |
<p>Viable tissue such as mammalian islets of Langerhans or liver tissue is encapsulated within a semipermeable membrane which allows the passage of oxygen, amino acids and nutrients needed for maintenance and ongoing metabolism of the tissue, but is impermeable to bacteria, lymphocytes, and proteins having a molecular weight above a selected level so as to exclude potentially deleterious large molecules such as immunoglobulins. By means of the process, and insulin generating system can be produced wherein mammalian islets are maintained in a viable and protected state within the capsule and excrete hormones. Also, mammalian liver tissue can be encapsulated for use as a body fluid detoxification system. The encapsulated liver tissue is shielded from plasma protein of the type responsible for immunological rejection and from leukocytes and bacteria, but toxins and nutrients required for maintenance and continued normal metabolism of the tissue freely traverse the membrane. The capsules may be injected into a suitable site in a mammalian body and act as an artificial organ, e.g., and artificial pancreas. The process comprises the steps of suspending the material to be encapsulated in a physiologically compatible medium such as a culture medium containing a water soluble substance which can be gelled into droplets to form discrete, shape-retaining temporary capsules, forming a semipermeable membrane about the temporary capsules, and optionally, reliquify the gelled interior, The process can also be used for encapsulating chemically active substances such as activated charcoal particles and labile biological materials.</p> |
