ORIGINAL ARTICLESBiodistribution study and identification of inflammatory sites using nanocapsules labeled with 99mTc–HMPAOPereira, Maira A.a; Mosqueira, Vanessa C. F.c; Carmo, Vildete A. S.a; Ferrari, Cristiano S.b; Reis, Eduardo C.O.a; Ramaldes, Gilson A.a; Cardoso, Valbert N.aAuthor Information aFaculdade de Farmácia, Universidade Federal de Minas Gerais bEcograf – Núcleo Diagnóstico, Rua Domingos Vieira, Belo Horizonte cEscola de Farmácia, Universidade Federal de Ouro Preto, Rua Costa Sena, Minas Gerais, Brazil Correspondence to Valbert N. Cardoso, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil Tel: +55 31 34096892; fax: +55 31 34096985; e-mail: email@example.com Received 17 May 2009 Revised 7 June 2009 Accepted 7 June 2009 Nuclear Medicine Communications: September 2009 - Volume 30 - Issue 9 - p 749-755 doi: 10.1097/MNM.0b013e32832f2b59 Buy Metrics Abstract Purpose To evaluate the ability of polymeric nanocapsules (NCs) radiolabeled with technetium-99m D,L-hexamethylpropyleneamine oxime (99mTc–HMPAO) to identify inflammatory process in an experimental model. Methods NCs were prepared by interfacial deposition of preformed biodegradable polymer [poly (D,L-lactic acid) (PLA) and PLA–PEG (polyethyleneglycol)] followed by a solvent displacement. The size and homogeneity, and ζ potential of the NC preparations were determined in a Zetasizer by photon correlation spectroscopy and laser Doppler anemometry, respectively. The NCs radiolabeled with 99mTc–HMPAO were administered intravenously to Wistar male rats bearing a focal inflammation induced by subplantar injection of carrageenan in the right foot. At preestablished time intervals, the animals were anesthetized, tissues were removed and radioactivity was determined using an automatic scintillation apparatus. Results The average diameter calculated by photon correlation spectroscopy varied from 216 to 323 nm. The biodistribution studies showed a greater uptake of the PEG surface-modified 99mTc–HMPAO-NC by the inflamed paws when compared with the respective controls. There was no significant difference in the uptake of conventional 99mTc–HMPAO-NC and of free 99mTc-HMPAO by inflamed and control paws. These results indicate that the PLA–PEG 99mTc-NC showed a higher uptake in inflammation compared with free complex and may be useful as a radiotracer to identify these foci. © 2009 Lippincott Williams & Wilkins, Inc.