Construction and application of biotin-poloxamer conjugate micelles for chemotherapeutics.

Biotin was conjugated on poloxamer to prepare biotin-poloxamer (BP) conjugate micelles for chemotherapeutics. Epirubicin (EPI) was encapsulated in BP micelles. The EPI-loaded BP micelles were characterized in terms of size, ζ-potential, morphology, drug loading, drug encapsulation and drug release. Marrow leukemic HL-60 cells were used for evaluating the in vitro cytotoxicity of EPI-loaded BP micelles. Nude mice were axillainoculated subcutaneously HL-60 cells to establish tumour model for investigating the inhibition effects of EPI-loaded BP micelles. From the results, the sizes of these nanoparticles were about 100 nm. Fluorescence microscope observation supported the enhanced cellular uptake of the micelles. The order of the inhibition on tumour volume growth was: EPI-loaded BP micelles >EPI-loaded MATP micelles >EPI-loaded poloxamer micelles >EPI. BP micelles showed significant antitumour activity and low toxicity, compared with the non-targeted micelles. With the advantage of EPR effect and tumour-targeting potential, BP conjugate micelles might be developed as a new system for chemotherapeutics.

Preparation and antitumor activity of bFGF-mediated active targeting doxorubicin microbubbles.

Characterization and antitumor activity of basic fibroblast growth factor-mediated active targeting doxorubicin microbubbles (bFGF-DOX-MB) were investigated. Pluronic F68 with chemical conjugation of doxorubicin (DOX-P) and peptide KRTGQYKLC-conjugated DSPE-PEG2000 were prepared. bFGF-DOX-MB had a normal distribution of particle size, with average particle size of 2.7 µm. Using A549 mouse model, bFGF-DOX-MB combined ultrasound showed the best inhibition effect on tumor volume growth among all the test groups. Similar conclusion was obtained from experimental measurements of tumor weight change and blood cell count. From the results, chemotherapeutic drug inhibition on tumor growth could be enhanced by local ultrasound combined with active targeting bFGF-DOX-MB, which might provide a potential application for ultrasound-mediated chemotherapy.

Biodegradable poly(D, L-lactide-co-glycolide) (PLGA) microspheres for sustained release of risperidone: Zero-order release formulation.

The preparation and investigation of sustained-release risperidone-encapsulated microspheres using erodible poly(D, L-lactide-co-glycolide) (PLGA) of lower molecular weight were performed and compared to that of commercial Risperdal Consta™ for the treatment of schizophrenia. The research included screening and optimizing of suitable commercial polymers of lower molecular weight PLGA50/50 or the blends of these PLGA polymers to prepare microspheres with zero-order release kinetics properties. Solvent evaporation method was applied here while studies of the risperidone loaded microsphere were carried out on its drug encapsulation capacity, morphology, particle size, as well as in vitro release profiles. Results showed that microspheres prepared using 50504A PLGA or blends of 5050-type PLGAs exerted spherical and smooth morphology, with a higher encapsulation efficiency and nearly zero-order release kinetics. These optimized microspheres showed great potential for a better depot preparation than the marketed Risperdal Consta™, which could further improve the patient compliance.

[Single-lung transplantation and contralateral lung volume reduction for emphysema].

OBJECTIVE: To report the operation technique, patient selection and curative effect of single-lung transplantation with contralateral lung volume reduction for a patient with end-stage emphysema. METHODS: A 47-year-old male patient who was dependent on mechanical ventilation because of end-stage emphysema received left-lung transplantation on 20 June, 2003. The surgical technique used was similar to that mentioned in the literature. The donor lung was perfused by low-potassium dextran solutions (LPD) with a cold ischemic time of 390 minutes. The patient received contralateral lung volume reduction because of subacute native lung hyperinflation on the 7th day after operation. He was received tracheostomy on 15th day after operation and was weaned from ventilator on the 26th day post-operation. Immunosuppression included cyclosporine, mycophenolate mofetil and corticosteroid. The acute rejection occurred on the 9th and 15th days after operation and was cured successfully. RESULTS: The lung function was improved significantly and the patient was discharged from hospital 71 days after operation. CONCLUSIONS: Single-lung transplantation combined with contralateral lung volume reduction for end-stage emphysema is an effective measure for subacute native lung hyperinflation. Further follow-up is required to assess the long term results of this procedure.

[Single-lung transplantation for end-stage emphysema].

OBJECTIVE: To evaluate operative technique, patient selection and perioperative management of single-lung transplantation for a patients with end-stage emphysema. METHODS: A 56-year-old patient with end-stage emphysema underwent left-lung transplantation on September 28, 2002. The surgical technique used was similar to that mentioned in the literature. The donor lung was perfused by LPD solution with a cold ischemic time of 260 minutes. Cardiopulmonary bypass was not performed. RESULTS: The patient weaned from a ventilator at the 93th hour after operation. Immunosuppressants included cyclosporine, mycophenolate mofetil and corticosteroid. Acute rejection occurred on the ninth day after operation and was cured by bolus methylprednisolone given intravenously. Lung function was improved significantly and the patient was discharged from the hospital on the 47th day after operation. CONCLUSION: Single-lung transplantation for patients with end-stage emphysema is effective for long-term improvement of pulmonary function.