Poly-ε-caprolactone based nanoparticles for delivery of genistein in melanoma treatment

We developed poly-ε-caprolactone (PCL)-based nanoparticles containing D-α-tocopherol polyethylene glycol-1000 succinate (TPGS) or Poloxamer 407 as stabilizers to efficiently encapsulate genistein (GN). Two formulations, referred to as PNTPGS and PNPol, were prepared using nanoprecipitation. They were characterized by size and PDI distribution, zeta potential, nanoparticle tracking analysis (NTA), GN association (AE%), infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC). PNTPGS-GN exhibited a particle size of 141.2 nm, a PDI of 0.189, a zeta potential of -32.9 mV, and an AE% of 77.95%. PNPol-GN had a size of 146.3 nm, a better PDI than PNTPGS-GN (0.150), a less negative zeta potential (-21.0 mV), and an AE% of 68.73%. Thermal and spectrometric analyses indicated that no new compounds were formed, and there was no incompatibility detected in the formulations. Cellular studies revealed that Poloxamer 407 conferred less toxicity to PCL nanoparticles. However, the percentage of uptake decreased compared to the use of TPGS, which exhibited almost 80% cellular uptake. This study contributes to the investigation of stabilizers capable of conferring stability to PCL nanoparticles efficiently encapsulating GN. Thus, the PCL nanoparticle proposed here is an innovative nanomedicine for melanoma therapy and represents a strong candidate for specific pre-clinical and in vivo studie

Three-dimensional culture models: emerging platforms for screening the antitumoral efficacy of nanomedicines.

Nanomedicines have been investigated for delivering drugs to tumors due to their ability to accumulate in the tumor tissues. 2D in vitro cell culture has been used to investigate the antitumoral potential of nanomedicines. However, a 2D model cannot adequately mimic the in vivo tissue conditions because of the lack of cell-cell interaction, a gradient of nutrients and the expression of genes. To overcome this limitation, 3D cell culture models have emerged as promising platforms that better replicate the complexity of native tumors. For this purpose, different techniques can be used to produce 3D models, including scaffold-free, scaffold-based and microfluidic-based models. This review addresses the principles, advantages and limitations of these culture methods for evaluating the antitumoral efficacy of nanomedicines.

Docetaxel-loaded folate-modified TPGS-transfersomes for glioblastoma multiforme treatment.

Glioblastoma multiforme (GBM) is a first primary Central Nervous System tumor with high incidence and lethality. Its treatment is hampered by the difficulty to overcome the blood-brain barrier (BBB) and by the non-specificity of chemotherapeutics to tumor cells. This study was based on the development characterization and in vitro efficacy of folate-modified TPGS transfersomes containing docetaxel (TF-DTX-FA) to improve GBM treatment. TF-DTX-FA and unmodified transfersomes (TF-DTX) were prepared through thin-film hydration followed by extrusion technique and characterized by physicochemical and in vitro studies. All formulations showed low particles sizes (below 200 nm), polydispersity index below 0.2, negative zeta potential (between -16.75 to -12.45 mV) and high encapsulation efficiency (78.72 ± 1.29% and 75.62 ± 0.05% for TF-DTX and TF-DTX-FA, respectively). Furthermore, cytotoxicity assay of TF-DTX-FA showed the high capacity of the nanocarriers to reduce the viability of U-87 MG in both 2D and 3D culture models, when compared with DTX commercial formulation and TF-DTX. In vitro cellular uptake assay indicated the selectivity of transfersomes to tumoral cells when compared to normal cells, and the higher ability of TF-DTX-FA to be internalized into 2D U-87 MG in comparison with TF-DTX (72.10 and 62.90%, respectively, after 24 h). Moreover, TF-DTX-FA showed higher permeability into 3D U-87 MG spheroid than TF-DTX, suggesting the potential FA modulation to target treatment of GBM.

Generation of a Three-Dimensional in Vitro Ovarian Cancer Co-Culture Model for Drug Screening Assays.

In vitro 3D culture models have emerged in the cancer field due to their ability to recapitulate characteristics of the in vivo tumor. Herein, we described the establishment and characterization of 3D multicellular spheroids using ovarian cancer cells (SKOV-3) in co-culture with mesenchymal cells (MUC-9) or fibroblasts (CCD27-Sk). We demonstrated that SKOV-3 cells in co-culture were able to form regular and compact spheroids with diameters ranging from 300 to 400 µm and with a roundness close to 1.0 regardless of the type of stromal cell used. In the 3D culture an increase was not observed in spheroid diameter nor was there significant cell growth. What is more, the 3D co-cultures presented an up regulation of genes related to tumorigenesis, angiogenesis and metastases (MMP2, VEGFA, SNAI1, ZEB1 and VIM) when compared with 2D and 3D monoculture. As expected, both 3D cultures (mono and co-cultures) exhibited a higher Paclitaxel chemoresistance when compared to 2D condition. Although we did not observe differences in the Paclitaxel resistance between the 3D mono and co-cultures, the gene expression results indicate that the presence of mesenchymal cells and fibroblasts better recapitulate the in vivo tumor microenvironment, being able, therefore, to more accurately evaluate drug efficacy for ovarian cancer therapy.

In vitro evaluation of folate-modified PLGA nanoparticles containing paclitaxel for ovarian cancer therapy.

Ovarian cancer is the most lethal gynecological cancer of female reproductive system. In order to improve the survival rate, some modifications on nanoparticles surfaces have been investigated to promote active targeting of drugs into tumor microenvironment. The aim of this study was the development and characterization of folate-modified (PN-PCX-FA) and unmodified PLGA nanoparticles (PN-PCX) containing paclitaxel for ovarian cancer treatment. Nanocarriers were produced using nanoprecipitation technique and characterized by mean particle diameter (MPD), polydispersity index (PDI), zeta potential (ZP), encapsulation efficiency (EE), DSC, FTIR, in vitro cytotoxicity and cellular uptake. PN-PCX and PN-PCX-FA showed MPD < 150 nm and PDI < 0.2 with high EE (about 90%). Cytotoxicity assays in SKOV-3 cells demonstrated the ability of both formulations to cause cellular damage. PCX encapsulated in PN-PCX-FA at 1 nM showed higher cytotoxicity than PN-PCX. Folate-modified nanoparticles showed a 3.6-fold higher cellular uptake than unmodified nanoparticles. PN-PCX-FA is a promising system to improve safety and efficacy of ovarian cancer treatment. Further in vivo studies are necessary to prove PN-PCX-FA potential.

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.

Poly-epsilon-caprolactone nanoparticles enhance ursolic acid in vivo efficacy against Trypanosoma cruzi infection.

Despite affecting millions of people worldwide, Chagas disease is still neglected by the academia and industry and the therapeutic option available, benznidazole, presents limited efficacy and side effects. Within this context, ursolic acid may serve as an option for treatment, however has low bioavailability, which can be enhanced through the encapsulation in polymeric nanoparticles. Therefore, herein we developed ursolic acid-loaded nanoparticles with poly-ε-caprolactone by the nanoprecipitation method and characterized them for particle size, zeta potential, polydispersity, encapsulation efficiency, morphology by scanning electron microscopy and thermal behavior by differential scanning calorimetry. Results indicated that an appropriate ratio of organic phase/aqueous phase and polymer/drug is necessary to produce smaller particles, with low polydispersity, negative zeta potential and high drug encapsulation efficiency. In vitro studies indicated the safety of the formulation against fibroblast culture and its efficacy in killing T. cruzi. Very importantly, the in vivo study revealed that the ursolic acid-loaded nanoparticle is as potent as the benznidazole group to control parasitemia, which could be attributed to improved bioavailability of the encapsulated drug. Finally, the toxicity evaluation showed that while benznidazole group caused liver toxicity, the nanoparticles were safe, indicating that this formulation is promising for future evaluation.

Impact of Pharmaceutical Care interventions in the identification and resolution of drug-related problems and on quality of life in a group of elderly outpatients in Ribeirão Preto (SP), Brazil.

OBJECTIVE: To evaluate the impact of a Pharmaceutical Care service in the identification and resolution of drug-related problems (DRPs) and in quality of life (QoL) of a group of elderly outpatients with chronic health conditions. METHODS: 30 outpatients (aged 60-75-years old) were followed between August 2003 and July 2004 at a primary health care unit in Ribeirão Preto (SP), Brazil. Patients were scheduled monthly to meet with the researcher, who provided Pharmaceutical Care service (the intervention). Through Pharmaceutical Care, the pharmacist worked with the patient and other care providers to improve outcomes of drug therapy through focused education, care planning, and monitoring. Intervention outcomes were the number of DRPs prevented or resolved, and the impact on QoL. The Short Form-36 health survey was used to measure changes in QoL. RESULTS: The mean age of patients was 66 ± 5 years, 21 of whom had low literacy. During the study, 92 DRP were identified, 3.0 ± 1.5 problems per patient. By the end of the study, the interventions solved 69% of actual DRP and prevented 78.5% potential DRP. In addition, QoL showed improvement in 22 patients after DRP resolution or prevention. CONCLUSION: Despite the limitations in this study that may affect generalizability of the results, this study demonstrates that humanistic and behavioral interventions based on the Pharmaceutical Care model were capable in reducing DRPs, and improve QoL in patients.