Inflammation: imaging with methoxy poly(ethylene glycol)-poly-L-lysine-DTPA, a long-circulating graft copolymer

Radiology. 1995 Dec;197(3):665-9. doi: 10.1148/radiology.197.3.7480736.

Abstract

Purpose: To test whether a nontargeted, long-circulating, synthetic polymer accumulates in areas of inflammation, with high capillary permeability and increased regional blood flow.

Materials and methods: Methoxy poly(ethylene glycol)-poly-L-lysine (PL)-diethylenetriaminepentaacetic acid (MPEG-PL-DTPA) was labeled with technetium-99m for scintigraphy and with gadolinium for magnetic resonance (MR) imaging. Eleven Escherichia coli-infected rats were injected with 1.0 mCi (37 MBq) of Tc-99m-labeled MPEG-PL-DTPA for scintigraphy. Twelve rats underwent 1.5-T MR imaging after intravenous injection of gadolinium-labeled MPEG-PL-DTPA (35 mumol/kg).

Results: Tc-99m-labeled MPEG-PL-DTPA demonstrated nearly eight-fold higher accumulation in infected muscle when compared with normal muscle. Scintigrams and MR images showed areas of inflammation with peak accumulation at 24 hours after injection of Tc-99m- or gadolinium-labeled MPEG-PL-DTPA.

Conclusion: Nontargeted, long-circulating, copolymers can efficiently accumulate in sites of inflammation and thus represent an alternative to inflammation-specific agents.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Capillary Permeability
  • Contrast Media* / pharmacokinetics
  • Disease Models, Animal
  • Escherichia coli Infections / diagnosis*
  • Escherichia coli Infections / diagnostic imaging
  • Escherichia coli Infections / metabolism
  • Escherichia coli Infections / pathology
  • Feasibility Studies
  • Gadolinium DTPA*
  • Gadolinium* / pharmacokinetics
  • Immunoglobulin G
  • Indium Radioisotopes
  • Injections, Intravenous
  • Magnetic Resonance Imaging
  • Male
  • Muscle, Skeletal / blood supply
  • Muscle, Skeletal / diagnostic imaging
  • Muscle, Skeletal / metabolism
  • Muscle, Skeletal / microbiology
  • Pentetic Acid / analogs & derivatives*
  • Pentetic Acid / pharmacokinetics
  • Polyethylene Glycols* / pharmacokinetics
  • Polylysine / analogs & derivatives*
  • Polylysine / pharmacokinetics
  • Radionuclide Imaging
  • Rats
  • Rats, Sprague-Dawley
  • Regional Blood Flow
  • Soft Tissue Infections / diagnosis*
  • Soft Tissue Infections / diagnostic imaging
  • Soft Tissue Infections / metabolism
  • Soft Tissue Infections / pathology
  • Technetium Tc 99m Pentetate* / pharmacokinetics
  • Thigh
  • Time Factors

Substances

  • Contrast Media
  • Immunoglobulin G
  • Indium Radioisotopes
  • monomethoxypolyethylene glycol-polylysine-gadolinium DTPA
  • Polylysine
  • Polyethylene Glycols
  • Pentetic Acid
  • Gadolinium
  • Gadolinium DTPA
  • Technetium Tc 99m Pentetate