Purpose-To evaluate the tumor targeting potential of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-gadolinium(Gd)-RGDfK conjugates by magnetic resonance (MR) T1-mapping.Methods-HPMA copolymers with and without RGDfK were synthesized to incorporate side chains for Gd chelation. The conjugates were characterized by their side-chain contents and r 1 relaxivity. In vitro integrin-binding affinities of polymeric conjugates were assessed via competitive cell binding assays on HUVEC endothelial cells and MDA-MB-231 breast cancer cells. In vivo MR imaging was performed on MDA-MB-231 tumor-bearing SCID mice at different time points using non-targetable and targetable polymers. The specificity of αvβ3 targeting was assessed by using nonparamagnetic targetable polymer to block αvβ3 integrins followed by injection of paramagnetic targetable polymers after 2 h.Results-The polymer conjugates showed relaxivities higher than Gd-DOTA. Endothelial cell binding studies showed that IC 50 values for the copolymer with RGDfK binding to αvβ3 integrinpositive HUVEC and MDA-MB-231 cells were similar to that of free peptide. Significantly lower T1 values were observed at the tumor site after 2 h using targetable conjugate (p<0.012). In vivo blocking study showed significantly higher T1 values (p<0.045) compared to targetable conjugate.Conclusion-These results demonstrate the potential of this conjugate as an effective targetable MR contrast agent for tumor imaging and therapy monitoring.

This study describes the synthesis, characterization and in vitro evaluation of targetable N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-gadolinium (Gd) chelates for enhanced magnetic resonance imaging (MRI) of macrophages. Copolymers of HPMA, methacryloylglycylglycyl-mannosamine (MA-GG-ManN), aminopropylmethacrylamide-benzyl-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (APMA-DOTA), and 5-(3-(methacryloylaminopropyl)thioureidyl) fluorescein (MA-AP-FITC) were synthesized and characterized. Gd was chelated to the polymeric precursors. The conjugates were characterized for gadolinium content by inductively coupled plasma optical emission spectrometry (ICP-OES) and T1 relaxivity (r1) at room temperature and 1.5 T. The effect of ManN content on mannose receptor mediated uptake of THP-1 human macrophages was evaluated as a function of time and temperature. The polymer conjugates showed relaxivities in the range of 21.8-24.9 s(-1) mM(-1) Gd. Relaxivities of the conjugates per mM Gd were up to 7 times higher than that of a commercially available MR contrast agent Gd-DOTA. Significantly (p < 0.042) higher uptake was observed for targeted conjugates compared to nontargeted conjugates. The uptake of polymeric conjugates was time and concentration dependent and appears to be mannose receptor mediated. The increased relaxivity coupled with the ability to target these carriers to cells containing ManN receptors shows promise for the application of these agents in clinical MR imaging of macrophage mediated malignancies.

This study describes the synthesis, characterization, and in vitro evaluation of N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-gadolinium (Gd)-doxorubicin (Dox) conjugates. Copolymers of HPMA were derivatized to incorporate side chains for Gd chelation and Dox conjugation. The conjugates were characterized by their side chain contents, T 1 relaxivity (r 1 ), stability, and in vitro cytotoxicity. High stability and relaxivity of these conjugates coupled with low toxicity show their potential for monitoring the in vivo fate of HPMA-based drug delivery systems by magnetic resonance imaging techniques.

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY) 11-07-2006 REPORT TYPE Final Technical Project Report DATES COVERED (From -To)June 2003 SPONSOR/MONITOR'S REPORT NUMBER(S)PP-1362 DISTRIBUTION / AVAILABILITY STATEMENT Unlimited Distribution SUPPLEMENTARY NOTES none ABSTRACTThis work details the stab ignition, small-scale sensitivity, and energy release characteristics of bimetallic Al/Ni(V) and Al/Monel energetic nanolaminate free-standing films. The influence of the engineered nanostructural features of the multilayersiscorrelated with both stab initiation and small-scale energetic materials testing results. Structural parameters of the thin films found to be important include the bi-layer period, total thickness of the film, and presence of coating Al layers. Live lead-free M55 stab detonators were prepared using energetic nanolaminate as the stab mix, cyanuric triazide as the transfer charge, and an Army formulation for the output charge. These lead-free detonators were demonstrated to have the acceptable stab sensitivity (21-35 mJ) as is required in current M55 detonators. There was evidence that the replacement of the current NOL-130 stab mix by compact powders of energetic multilayers does not affect the performance of the stab detonator. SUBJECT TERMS

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.