Development, characterization and biological in vitro assays of paclitaxel-loaded PCL polymeric nanoparticles.

Adenocarcinoma is the most lethal gynecologic tumor and treatment usually consists in surgery followed by chemotherapy. However, the chemotherapy benefits are eventually limited due to drug toxicity to normal tissues and cells, which cause several and harsh side effects. Paclitaxel (PCX) is the drug of first choice for ovarian cancer treatment, but it has low aqueous solubility, which reduces its bioavailability. Thus, in the commercial drug, Taxol®, PCX is solubilized in a mixture of toxic surfactants. The development of drug nanocarriers has been investigated to promote the reduction of toxic effects and increase the safety and therapeutic efficacy of PCX. The aim of this work was the development and characterization of PCX loaded nanoparticles (PNPCX) and evaluation of in vitro efficacy of developed system using adenocarcinoma cell line. The nanocarrier was successfully obtained using nanoprecipitation technique. The results showed that the PNPCX-A had a particle size distribution around 140 nm and polydispersity index smaller than 0.1, with high PCX encapsulation efficiency. The results obtained were suitable for the intravenous administration route and promotion of passive targeting in the tumor microenvironment. The in vitro cytotoxicity assays of SKOV-3 cell line demonstrated that PNPCX-A was able to release PCX and reduce cell viability. The flow cytometry assays first reported that a nanostructured system with such composition (PNPCX-A) presented a time dependent cellular uptake, showing the ability of nanocarrier to be internalized. PNPCX-A present a distinguish potential for ovarian cancer therapy optimization. In vivo studies are needed to confirm the in vitro results and provide additional data regarding safety and efficacy of ovarian cancer treatment.

Approaches for recombinant human factor IX production in serum-free suspension cultures.

OBJECTIVE: To establish a serum-free suspension process for production of recombinant human factor IX (rhFIX) based on the human cell line HEK 293T by evaluating two approaches: (1) serum-free suspension adaptation of previously genetic modified cells (293T-FIX); and (2) genetic modification of cells already adapted to such conditions (293T/SF-FIX). RESULTS: After 10 months, 293T-FIX cells had become adapted to FreeStyle 293 serum-free medium (SFM) in Erlenmeyer flasks. After 48 and 72 h of culture, 2.1 µg rhFIX/ml and 3.3 µg rhFIX/ml were produced, respectively. However, no biological activity was detected. In the second approach, wild-type 293T cells were adapted to the same SFM (adaptation process took only 2 months) and then genetically modified for rhFIX production. After 48 h of culture, rhFIX reached 1.5 µg/ml with a biological activity of 0.2 IU/ml, while after 72 h, the production was 2.4 µg/ml with a biological activity of 0.3 IU/ml. CONCLUSION: The findings demonstrate that the best approach to establish an rhFIX production process in suspension SFM involves the genetic modification of cells already adapted to the final conditions. This approach is time saving and may better ensure the quality of the produced protein.