RESUMO
A new approach to the fabrication of magnetic thermosensitive microcontainers of Fe(3)O(4) nanoparticles with poly(N-isopropylacrylamide) walls is presented. The microcontainers undergo a temperature-induced volume phase transition and present an impressive magnetic response. The microcontainers have a well-defined structure with a narrow size distribution. The wall thicknesses of the microcontainers can be controlled according to requirements. Compared to other preparation methods, the process is simple and reproducible. The magnetic saturation of these microcontainers is high enough to meet most requirements of bioapplications. To further investigate the potential application of these microcontainers, they are tested as drug carriers, with the drug loading and releasing processes carefully studied. The drug encapsulation efficiency and drug content in the carriers are pH-dependent, and the carriers have a maximal drug loading of about 50 wt% under alkaline conditions. The release of the drug from the microcontainers can be controlled by the environmental pH, temperature, and magnetic force.
Assuntos
Resinas Acrílicas/química , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Portadores de Fármacos/química , Portadores de Fármacos/efeitos da radiação , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Difusão , Campos Eletromagnéticos , Teste de Materiais , Nanomedicina/métodos , Tamanho da Partícula , TemperaturaRESUMO
Doxorubicin is a classic anticancer agent. Recently, numerous strategies have been used to enhance efficacy of drug delivery for cancer treatment. For example, by modifying poly(N-isopropylacrylamide) microspheres, a nanocarrier, makes it more effective. Conjugation with folic acid increases specific targeted drug delivery towards folate receptor-bearing cancer cells to improve anticancer effectiveness by increasing the tissue's local concentration of drugs. In the current studies, we synthesized folate-bearing, doxorubicin-loaded, magnetic, poly(N-isopropylacrylamide) microspheres (FDMPM) to treat breast cancer cells (human SKBR-3). We found efficiency of drug encapsulation very high (95%) at pH above 7.4. Reverse transcription-PCR showed that cancer cells highly expressed folate receptors. Confocal laser scanning microscopy and flow cytometry revealed internalization of the carrier by SKBR-3 in treatments with FDMPM, which was not the case with any other combination for drug delivery (MPM, FMPM, and DMPM). Similarly, SKBR-3 cell growth was inhibited more (assessed by methylthiazolyldiphenyl-tetrazolium bromide and trypan blue exclusion assays) when treated with FDMPM than with any other combinations. Current results confirm our predication and demonstrate that FDMPM has potential as a new targeting strategy in cancer therapy.
Assuntos
Antibióticos Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Doxorrubicina/farmacologia , Ácido Fólico/química , Resinas Acrílicas/química , Antibióticos Antineoplásicos/administração & dosagem , Neoplasias da Mama/fisiopatologia , Linhagem Celular Tumoral , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos , Feminino , Citometria de Fluxo , Humanos , Concentração de Íons de Hidrogênio , Magnetismo , Microscopia Confocal , Microesferas , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Preclinical studies have demonstrated that Apatinib, major targeting vascular endothelial growth factor receptor-2 (VEGFR-2), could inhibit the proliferation of anaplastic thyroid carcinoma (ATC) cells in vitro and in vivo. The efficacy and safety in ATC patients, however, remains unknown. Here, we report the case of a 93-year-old female with advanced ATC who initially treated with Apatinib. The tumor shrank notably 4 weeks after the initiation of therapy, which sustained for more than 30 weeks. The cervical CT illuminated a stable disease with a best response of 19.7% of the primary lesion and shrinkage of the metastatic lymph node. Adverse events, including hypertension, dental ulcer, hand-foot syndrome, fatigue, and anorexia, were observed and lightened with supportive treatment and dose reductions. The overall survival of the patient was 41 weeks. This is the first report describing the effectiveness of the VEGFR-2 inhibitor for the treatment of advanced ATC, warranting clinical trials to further ascertain its utility in this challenging setting.
RESUMO
A 74-year-old patient was admitted to our hospital with recurrent ameloblastoma of the right mandible. Multiple lung nodules were noted during the presurgical evaluation. FDG PET/CT was subsequently performed to assess the nature of the nodules and search the possible primary tumors. The images showed abnormal FDG activity not only in the lung nodules but also in the lumbar vertebral body and the liver. Pathologic examination after hepatic biopsy demonstrated metastases from ameloblastoma.