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Fiberoptic microneedle device facilitates volumetric infusate dispersion during convection‐enhanced delivery in the brain
Author(s) -
Hood R. Lyle,
Andriani Rudy T.,
Emch Samantha,
Robertson John L.,
Rylander Christopher G.,
Rossmeisl John H.
Publication year - 2013
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.22156
Subject(s) - biomedical engineering , in vivo , hyperthermia , evans blue , chemistry , nuclear medicine , materials science , medicine , biology , microbiology and biotechnology , endocrinology
Background and Objectives A fiberoptic microneedle device (FMD) was designed and fabricated for the purpose of enhancing the volumetric dispersal of macromolecules delivered to the brain through convection‐enhanced delivery (CED) by concurrent delivery of sub‐lethal photothermal hyperthermia. This study's objective was to demonstrate enhanced dispersal of fluid tracer molecules through co‐delivery of 1,064 nm laser energy in an in vivo rodent model. Materials and Methods FMDs capable of co‐delivering fluids and laser energy through a single light‐guiding capillary tube were fabricated. FMDs were stereotactically inserted symmetrically into both cerebral hemispheres of 16 anesthetized rats to a depth of 1.5 mm. Laser irradiation (1,064 nm) at 0 (control), 100, and 200 mW was administered concurrently with CED infusions of liposomal rhodamine (LR) or gadolinium–Evans blue‐serum albumin conjugated complex (Gd–EBA) at a flow rate of 0.1 µl/min for 1 hour. Line pressures were monitored during the infusions. Rodents were sacrificed immediately following infusion and their brains were harvested, frozen, and serially cryosectioned for histopathologic and volumetric analyses. Results Analysis by ANOVA methods demonstrated that co‐delivery enhanced volumetric dispersal significantly, with measured volumes of 15.8 ± 0.6 mm 3 for 100 mW compared to 10.0 ± 0.4 mm 3 for its fluid only control and 18.0 ± 0.3 mm 3 for 200 mW compared to 10.3 ± 0.7 mm 3 for its fluid only control. Brains treated with 200 mW co‐delivery exhibited thermal lesions, while 100 mW co‐deliveries were associated with preservation of brain cytoarchitecture. Conclusion Both lethal and sub‐lethal photothermal hyperthermia substantially increase the rate of volumetric dispersal in a 1 hour CED infusion. This suggests that the FMD co‐delivery method could reduce infusion times and the number of catheter insertions into the brain during CED procedures. Lasers Surg. Med. 45:418–426, 2013. © 2013 Wiley Periodicals, Inc.