COMPUTATIONAL TASKS IN MEDICAL NANOROBOTICS - Bio-Inspired and Nanoscale Integrated Computing - page 408

Yet another biocompatibility-related complication is that the bare tissue walls
of a wound will continue to exude fluid [2j], and may begin to desiccate, if only the
capillary termini are sealed but the rest of the tissue is left exposed to open air.
Since clottocytes may remain attached to their discharged nets, and can commu-
nicate with each other via acoustic channels [1m], it should be possible to precisely
control the development of a larger artificial mesh-based clot via coordinated
mesh extensions or retractions within the clot. Alternatively, clottocytes could
allow blood fluids to flood small incised or avulsed wound volumes, allowing
exposed tissue walls to be bathed in fluids but casting a watertight sealant net
across the wound opening flush with the epidermal plane of the wound cavity. The
operational protocols that trigger and direct these behaviors will need to be rather
complex to ensure safe and fully biocompatible operation.
Additional protocols are required to allow clottocytes to prevent accidental
but potentially fatal catastrophic natural clotting cascades such as disseminated
intravascular coagulation or DIC [57]. One solution is to equip clottocytes with
sensors to detect decreased serum levels of fibrinogen, plasminogen, alpha 2 -
antiplasmin, antithrombin III, factor VII, and protein C, and elevated levels of
thrombin and various fibrin/fibrinogen-derived degradation products [2i]. If DIC
conditions arise, nanorobots might respond by absorbing and metabolizing the
excess thrombin (which trigger clotting), or by releasing thrombin inhibitors such
as antithrombin III, hirudin, argatroban, or lepirudin [58] or anticoagulants that
reduce thrombin generation such as danaparoid [58] to interrupt the cascade
[58, 59]. For example, a

0.02% Nct concentration of nanorobots, suitably
activated according to physician-approved parameters, could replace the entire
depleted natural bloodstream content of antithrombin III from onboard stores in
seconds.
Clottocytes will require still more sophisticated operational protocols if they
are intended to assist platelets participating in the sealing of internal blood vessel
lesions, in order to avoid inadvertently blocking the lumen of the entire vessel, e.g.,
in the case of minor internal bleeding. Similarly, prevention of bleeding at vascular
anastomoses, hemarthroses, internal bruising, ''blood blisters,'' and larger tissue
hematomas, as well as forced local coagulation in tumors or in intracerebral
aneurysms, may also require more advanced protocols, possibly including
integration with preexisting in vivo navigation systems [1an]. For some of these
applications, modified clottocytes possessing the mobility of microbivores may be
required in tandem with a graduated recruitment response depending upon how
many (intercommunicating) devices appear to be involved in the event.

B

15.2.4. Chromallocytes
15.2.4.1. Nanorobot Description. The chromallocyte [7] is a hypothetical
mobile cell-repair nanorobot whose primary purpose is to perform chromosome
replacement therapy (CRT). In CRT, the entire chromatin content of the nucleus
in a living cell is extracted and promptly replaced with a new set of prefabricated
chromosomes which have been artificially manufactured as defect-free copies of