The Effect of Therapy Regimen on Antitumor Efficacy of the Nanosomal Doxorubicin against Rat Glioblastoma 101.8.

One of the key problems of glioblastoma treatment is the low effectiveness of chemotherapeutic drugs. Incorporation of doxorubicin into PLGA nanoparticles allows increasing the antitumor effect of the cytostatics against experimental rat glioblastoma 101.8. Animal survival, tumor volume, and oncogene expression in tumor cells were compared after early (days 2, 5, and 8 after tumor implantation) and late (days 8, 11, and 14) start of the therapy. At late start, a significant increase in the expression of oncogenes Gdnf, Pdgfra, and Melk and genes determining the development of multidrug resistance Abcb1b and Mgmt was revealed. At early start of therapy, only the expression of oncogenes Gdnf, Pdgfra, and Melk was enhanced. Early start of treatment prolonged the survival time and increased tumor growth inhibition by 141.4 and 95.7%, respectively, in comparison with the untreated group; these differences were not observed in the group with late start of therapy. The results indicate that the time of initiation of therapy is a critical parameter affecting the antitumor efficacy of DOX-PLGA.

[Nitric oxide donor nitrosorbide potentiates the antitumor effect of doxorubicin against experimental glioblastoma]. / Donor oksida azota izosorbida dinitrat povyshaet protivoopukholevyi effekt doksorubitsina pri khimioterapii eksperimental'noi glioblastomy.

BACKGROUND: Doxorubicin is a well-known antitumor drug that is not employed for chemotherapy of brain tumors. Indeed, doxorubicin does not penetrate across the blood-brain barrier in therapeutic concentrations. OBJECTIVE: To study the antitumor effect of doxorubicin combined with nitrosorbide on intracranial experimental glioblastoma 101/8 in rats. MATERIAL AND METHODS: Male Wistar rats (n=86) with intracranial implanted glioblastoma 101/8 received doxorubicin (i.v. 1.5 mg/kg thrice) alone or in combination with nitrosorbide (i.v or orally, 0.5 mg/kg thrice) in 2, 5 and 8 days after implantation. Efficacy was assessed considering survival and brain tumor volume in 14 days after tumor implantation. RESULTS: Combination of doxorubicin and nitrosorbide significantly increased survival (57% and 155%, respectively) and slowed down tumor growth (16±12 and 8±6 mm3, respectively) compared to doxorubicin alone. Effectiveness of nitrosorbide alone was trivial. CONCLUSION: Nitric oxide donor nitrosorbide considerably potentiated the antitumor effect of doxorubicin against intracranial 101/8 glioblastoma in rats.

Simultaneous determination of rifabutin and human serum albumin in pharmaceutical formulations by capillary electrophoresis.

Capillary zone electrophoresis (CZE) was used for determination of rifabutin (RFB), an anti-tuberculosis antibiotic drug, in various pharmaceutical formulations. Apart from that, simultaneous determination of RFB and human serum albumin (HSA) was performed. Electrophoretic behaviour of RFB was examined at various pH levels. CE conditions: a quartz capillary tube (internal diameter 75mm, effective length 50cm, total length 60cm), the capillary temperature was 25°Ð¡, the voltage applied to the capillary tube was +20kV, the UV detection wavelength was 214nm, hydrodynamic injection of the sample was performed at 30mbar for 5s, tetraborate buffer solution (0.01М, рН9.2). The obtained results are characterized by high efficiency (number of theoretical plates up to 260,000) and sufficient sensitivity (LOQ starting from 0.02µg/ml for RFB). The obtained data are in good accord with both HPLC results (for RFB) and spectrophotometry (for HSA).

[Toxicological Evaluation of Intravenous Formulation of Rifapentine.]

Rifapentine belongs to the most potent antituberculosis drugs. Nevertheless, there are some limitations for its clinical use because of the low aqueous solubility and side effects. A technological approach to development of rifapentine intravenous formulation based on human serum albumin was described earlier and its efficacy against experimental tuberculosis was estimated. Toxicological evaluation of that water-compatible form of rifapentine revealed its low acute toxicity (LD50 340 mg/kg). Chronic toxicity tests of both the oral substance and the injectable formulation of rifapentine demonstrated similar adverse effects. However, in contrast to the conventional oral formulations, the intravenous formulation of rifapentine had no gastrointestinal toxic effects or cardiotoxicity, thus suggesting its usefulness for clinical application.

Arylsulfatase A bound to poly(butyl cyanoacrylate) nanoparticles for enzyme replacement therapy--physicochemical evaluation.

Arylsulfatase A (ASA) deficiency is the cause of metachromatic leucodystrophy (MLD), a lysosomal storage disease associated with severe neurological disorders. Poly(butyl cyanoacrylate) (PBCA) nanoparticles overcoated with polysorbate 80 enabled the delivery of several drugs across the blood-brain barrier to the brain suggesting that these nanoparticles also may transport ASA across this barrier. The objective of this research, therefore, was to evaluate the feasibility of loading ASA onto PBCA nanoparticles. A stable ASA-loaded PBCA nanoparticle formulation was developed that could be easily freeze-dried and stored over a period of more than 8 weeks. The maximum loading capacity for this enzyme was -59 microg per 1 mg of PBCA. In the presence of 3% sucrose as a lyoprotector the activity of freeze-dried ASA was found to be 100% recoverable.

Development of nanoparticle-bound arylsulfatase B for enzyme replacement therapy of mucopolysaccharidosis VI.

Lysosomal storage disorders like mucopolysaccharidosis (MPS) VI are rare diseases with a lack of well-suited treatments. Even though an enzyme replacement therapy (ERT) of recombinant arylsulfatase B (ASB) is available for MPS VI, the administration cannot positively affect the neurologic manifestations such as spinal cord compression. Since nanoparticles (NP) have shown to be effective drug carriers, the feasibility of arylsulfatase B adsorption onto poly(butyl cyanoacrylate) (PBCA) nanoparticles was investigated in this study. In order to advance the ERT of ASB, the adsorption of the latter on the surface of PBCA NP as well as in vitro release in serum was investigated. With alteration of parameters like temperature, incubation time, pH, and enzyme amount, the adsorption process revealed to be stable with a maximum capacity of 67 microg/mg NP at a pH of 6.3. In vitro release experiments demonstrated that the adsorption is stable for at least 60 minutes in human blood serum, indicating that the ASB-loaded PBCA nanoparticles represent a promising candidate for ERT of MPS VI.

Efficient systemic therapy of rat glioblastoma by nanoparticle-bound doxorubicin is due to antiangiogenic effects.

The objective of this study was to investigate the therapeutic effects of doxorubicin bound to polysorbate-coated nanoparticles that had previously been shown to significantly enhance survival in the orthotopic rat 101/8 glioblastoma model. Tumor-bearing animals were subjected to chemotherapy using doxorubicin in solution (Dox-sol) or doxorubicin bound to polysorbate 80-coated poly(butyl cyanoacrylate) nanoparticles (Dox-np) injected intravenously on Days 2, 5 and 8 post tumor implantation. The antitumor effect was assessed on Days 10, 14 and 18 post tumor implantation. Tumors showed signs of malignancy including invasion of brain tissue, brisk mitotic activity, microvascular proliferation, necrosis and increased proliferation resembling human glioblastoma. Dox-np produced a considerably more pronounced antitumor effect exhibited as a reduced tumor size, lower proliferation, and a decreased necrotic area compared to Dox-sol and to untreated control groups. A drastic effect of Dox-np on vascularization indicated an antiangiogenic mode of action.

Intravenous tolerance of a nanoparticle-based formulation of doxorubicin in healthy rats.

A comparative toxicological study of doxorubicin bound to poly(butyl cyanoacrylate) nanoparticles coated with polysorbate 80 was performed in male and female Wistar rats. The drug substance was used as a reference formulation. The formulations were injected intravenously at a therapeutic dose of 6 mg/kg administered either as a single injection or in form of four weekly injections. The animals were followed up for 4 and 40 days (single injection) or 25 and 61 days (multiple injections) for assessment of the dynamics of body weight, hematological parameters, blood biochemical parameters, and urinalysis. Pathomorphological evaluation included macroscopic evaluation and weight measurement of the internal organs. The heart, lung, spleen, testes, and liver were also subjected to the histological evaluation. The overall result of this study suggests that the surfactant-coated nanoparticle formulation of doxorubicin has a favorable toxicological profile. Specifically, this formulation displays a considerably reduced cardio- and testicular toxicity, as compared to a free drug.

Radiation sterilisation of doxorubicin bound to poly(butyl cyanoacrylate) nanoparticles.

Doxorubicin-loaded poly(butyl cyanoacrylate) (PBCA) nanoparticles were prepared by anionic polymerisation under non-aseptic conditions. The feasibility of sterilisation of this formulation using either gamma-irradiation or electron beam irradiation was investigated. The irradiation doses ranged from 10 to 35 kGy. Bacillus pumilus was used as the official test microorganism. The bioburden of the untreated formulation was found to be 100 CFU/g. Microbiological monitoring revealed that at this level of the bioburden the irradiation dose of 15 kGy was sufficient for sterilisation of the nanoparticles. The formulation showed excellent stability with both types of irradiation in the investigated dose range. The irradiation did not influence the physicochemical parameters of the drug-loaded and empty nanoparticles, such as the mean particle size, polydispersity, and aggregation stability. The molecular weights of the PBCA polymer as well as the polydispersity indices (M(w)/M(n)) remained nearly unchanged. The drug substance was stable to radiolysis. Additionally, the presence of irradiation-induced radicals was evaluated by ESR spectroscopy after storage of the particles at ambient temperature. The paramagnetic species found in the formulation were mainly produced by irradiation of mannitol and dextran used as excipients.

Encapsulation of moxifloxacin within poly(butyl cyanoacrylate) nanoparticles enhances efficacy against intracellular Mycobacterium tuberculosis.

Macrophages in the lungs are the most important cell type supporting replication of Mycobacterium tuberculosis in humans. The objective of this study was to investigate whether the effect of moxifloxacin against M. tuberculosis residing in macrophages could be improved by encapsulation of the drug in the biodegradable nanoparticles, which are known to accumulate in macrophages upon intravenous administration. To accomplish this, moxifloxacin was encapsulated in poly(butyl cyanoacrylate) (PBCA) nanoparticles. Encapsulated moxifloxacin accumulated in macrophages approximately three-fold times more efficiently than the free drug, and was detected in the cells for at least six times longer than free moxifloxacin at the same extracellular concentration. Inhibition of intracellular M. tuberculosis growth with encapsulated moxifloxacin was achieved at the concentration of 0.1microg/ml, whereas the same effect with free MX required a concentration of 1microg/ml. Nanoparticles observed within the macrophage cytoplasm were distributed throughout the cytoplasm, sometimes in the vicinity of intracellular bacteria.

Influence of the formulation on the tolerance profile of nanoparticle-bound doxorubicin in healthy rats: focus on cardio- and testicular toxicity.

A toxicological study of doxorubicin bound to poly(butyl cyanoacrylate) or human serum albumin nanoparticles coated with polysorbate 80 was performed in healthy rats. The doxorubicin formulations were injected at a therapeutic dose regimen (3 x 1.5 mg/kg with a 72 h interval), and the animals were followed up for 15 or 30 days. The overall result of this study suggests that the surfactant-coated nanoparticle formulations of doxorubicin have favorable toxicological profiles. Specifically, these formulations display a considerably reduced cardio- and testicular toxicity, as compared to a free drug.

Chemotherapy of brain tumour using doxorubicin bound to surfactant-coated poly(butyl cyanoacrylate) nanoparticles: revisiting the role of surfactants.

Poly(butyl cyanoacrylate) nanoparticles coated with poloxamer 188 (Pluronic) F68) and also, as shown previously, polysorbate 80 (Tween 80) considerably enhance the anti-tumour effect of doxorubicin against an intracranial glioblastoma in rats. The investigation of plasma protein adsorption on the surface of the drug-loaded nanoparticles by two-dimensional electrophoresis (2-D PAGE) revealed that both surfactants, besides other plasma components, induced a considerable adsorption of apolipoprotein A-I (ApoA-I). It is hypothesized that delivery of doxorubicin to the brain by means of nanoparticles may be augmented by the interaction of apolipoprotein A-I that is anchored on the surface of the nanoparticles with the scavenger receptor class B type I (SR-BI) located at the blood-brain barrier. This is the first study that shows a correlation between the adsorption of apolipoprotein A-I on the nanoparticle surface and the delivery of the drug across the blood-brain barrier.

Toxicological studies of doxorubicin bound to polysorbate 80-coated poly(butyl cyanoacrylate) nanoparticles in healthy rats and rats with intracranial glioblastoma.

Polysorbate 80-coated poly(butyl cyanoacrylate) nanoparticles (NP) were shown to enable the transport of a number of drugs including the anti-tumour antibiotic doxorubicin (DOX) across the blood-brain barrier (BBB) to the brain after intravenous administration and to considerably reduce the growth of brain tumours in rats. The objective of the present study was to evaluate the acute toxicity of DOX associated with polysorbate 80-coated NP in healthy rats and to establish a therapeutic dose range for this formulation in rats with intracranially implanted 101/8 glioblastoma. Single intravenous administration of empty poly(butyl cyanoacrylate) NP in the dose range 100-400 mg/kg did not cause mortality within the period of observation. NP also did not affect body weight or weight of internal organs. Association of DOX with poly(butyl cyanoacrylate) NP did not produce significant changes of quantitative parameters of acute toxicity of the anti-tumour agent. Likewise, the presence of polysorbate 80 in the formulations was not associated with changes in toxicity compared with free or nanoparticulate drug. Dose regimen of 3x1.5 mg/kg on days 2, 5, 8 after tumour implantation did not cause drug-induced mortality. The results in tumour-bearing rats were similar to those in healthy rats. These results demonstrate that the toxicity of DOX bound to NP was similar or even lower than that of free DOX.

Significant transport of doxorubicin into the brain with polysorbate 80-coated nanoparticles.

PURPOSE: To investigate the possibility of delivering of anticancer drugs into the brain using colloidal carriers (nanoparticles). METHODS: Rats obtained 5 mg/kg of doxorubicin by i.v. injection in form of 4 preparations: 1. a simple solution in saline, 2. a simple solution in polysorbate 80 1% in saline, 3. bound to poly(butyl cyanoacrylate) nanoparticles, and 4. bound to poly(butyl cyanoacrylate) nanoparticles overcoated with 1% polysorbate 80 (Tween 80). After sacrifice of the animals after 10 min, 1, 2, 4, 6, and 8 hours, the doxorubicin concentrations in plasma, liver, spleen, lungs, kidneys, heart and brain were determined after extraction by HPLC. RESULTS: No significant difference in the body distribution was observed between the two solution formulations. The two nanoparticle formulations very significantly decreased the heart concentrations. High brain concentrations of doxorubicin (>6 microg/g) were achieved with the nanoparticles overcoated with polysorbate 80 between 2 and 4 hours. The brain concentrations observed with the other three preparations were always below the detection limit (< 0.1 microg/g). CONCLUSIONS: The present study demonstrates that the brain concentration of systemically administered doxorubicin can be enhanced over 60-fold by binding to biodegradable poly(butyl cyanoacrylate) nanoparticles, overcoated with the nonionic surfactant polysorbate 80. It is highly probable that coated particles reached the brain intact and released the drug after endocytosis by the brain blood vessel endothelial cells.