Preparation and investigation of core-shell nanoparticles containing human interferon-α.

Sustained release of active interferon-α (IFN-α) has been achieved from core-shell nanoparticles (NPs) prepared by aqueous precipitation of IFN-α-enriched human serum albumin (HSA-IFN-α) and layer-by-layer (L-b-L) by coating of the IFN-α NPs with poly(sodium-4-styrene) sulphonate (PSS) and chitosan (Chit). The concentration and the pH of HSA solution were optimized during the development of this method. Dynamic light scattering (DLS), zeta-potential, thermal analysis (differential scanning calorimetry (DSC) and termogravimetry (TG)), X-ray diffraction (XRD), IFN-α activity and morphology (transmission electron microscope (TEM)) studies were used to control the preparation and analyse the products. The dissolution kinetics of NPs was measured in vitro over 7 days in Hanson dissolution tester with Millex membrane. In vivo studies in Pannon white rabbit detected steady IFN-α plasma level for 10 days after subcutaneous injection administration of the HSA-IFN-α NPs. The IFN-α plasma concentration was detected by using the enzyme-linked immunosorbent assay (ELISA) method. In the present paper we discuss the preparation method, the optimization steps and the results of in vitro and in vivo release studies. It was established that 76.13% HSA-IFN-α are encapsulated in the core-shell NPs.

Oxidative stress with altered element content and decreased ATP level of erythrocytes in hepatocellular carcinoma and colorectal liver metastases.

Our aim was to study the possible alterations of redox status (enzymatic and nonenzymatic parameters and metal elements) in erythrocytes of patients with hepatocellular carcinoma (HCC), colorectal liver metastases (CRLM) and benign liver neoplasms. The function of redox homeostasis is closely connected to the energy level of erythrocytes, therefore, the ATP level was also determined. Antioxidant parameters, enzyme activities of superoxide dismutase and glutathione peroxidase were estimated in the erythrocytes of 11 patients with benign tumour, 23 patients with primary malignant and 37 metastatic liver tumour patients and 30 age-matched and sex-matched healthy controls. Element content with inductively coupled plasma optical emission spectrometer and ATP level by the chemiluminometric method were also determined from the samples. Free radical intensity was significantly increased, whereas erythrocyte glutathione peroxidase and superoxide dismutase activities were significantly decreased in the HCC and CRLM groups versus benign groups and controls. Se, Mn and Zn levels were lowered in HCC and CRLM groups versus benign and control groups. The content of Cu, Mg, Se and Zn changed significantly between HCC and CRLM groups. Similarly, ATP concentration decreased in HCC and CRLM versus controls and benign groups. The lowest levels of ATP and antioxidant enzyme activities were found in the case of CRLM patients. These results reveal an alteration in the ATP level of erythrocytes with concomitant changes in the antioxidant defence system in hepatic cancer patients. Altered redox homeostasis (oxidative damage) may lead to decreased ATP level and consequently may play an important role in primary carcinogenesis and generation of metastases, as well.

[Investigation of redox homeostasis in liver and renal transplant recipients]. / Redox homeostasis vizsgálata máj- és vesetranszplantáció során.

The time course of free radical reactions is evaluated by the authors. Within pretransplant patients as of their poorly functioning metabolism free radical overproduction may be observed, hence their antioxidant capacity decreases. When the graft is functioning well, the free radical-antioxidant balance of homeostasis is reestablished. During the early postoperative period, when symptoms (acute rejection, infection, acute tubular necrosis, cholestasis) appear, free radical reactions increase. The authors demonstrate, this is strengthened by the fact that the mediator [interleukin-6 (IL-6), C-reactive protein, serum amyloid-A], and enzyme levels that take part in the free radical processes rise. The monitoring of these parameters during the early postoperative period is a good early indicator for acute rejection and for the effect of therapy. During acute rejection just as during infection most of these parameters increased significantly compared to the healthy control. They show the activation of the immune system but they are not useful for differential diagnosis, with the exception of IL-6 which we measured in larger quantities during bacterial infection but not so in acute rejection. For the prediction of early renal graft function we used urinary enzyme levels (dipeptidyl-aminopeptidase, glutathione-S-transferase). Tissue damage is followed by enzyme increasing and antioxidant capacity depletion. With choosing of adequate tests, the perioperative redox homeostasis of the transplanted patients can be monitored and with dosing the antioxidants the uncontrolled forming of reactive oxygen metabolites can also be decreased and checked.

Formulation of an intermediate product from human serum albumin for the production of a solid dosage form.

The main objective of this study was to evaluate and to increase the processibility of a model protein (human serum albumin (HSA)) for preparation of an intermediate for a solid dosage form. The applicability of the solid forms is easier, and therefore their formulation is a promising method for the application of proteins. The layering of powdered cellulose with HSA solutions of different concentrations in a fluid bed apparatus with the top spray method was applied. The yield of this technique was very good, independently of the concentration of the applied solution. The HSA covered the particles (the HSA layer formed was smooth), but it caused aggregation of the cellulose particles, and spray-dried microparticles also formed. The proportion of optimum-sized particles (200-315 microm) decreased. The largest amount was detected for the samples prepared with liquid containing 15% HSA (about 2 times higher than the second best). Not only the size, but also the shape of the particles was changed. The alteration in this parameter caused a change in the flowability. This was likewise the best for the samples prepared with the liquid containing 15% HSA. The concentration of HSA in the fraction containing smaller particles was higher, because of the abrasion of the particles and the enrichment of the spray-dried HSA. The distribution of HSA in the large particles was uneven. The layering of powder cellulose can be applied to produce an intermediate from HSA for solid dosage forms, but the appropriate concentration of this protein solution must be optimized previously because HSA can act as a binder. The formation of large agglomerates must be eliminated, because the distribution of the active agent in these is very inhomogeneous. The present results indicated that the best value can be achieved with liquid containing between 12.5% (most homogeneous distribution of HSA) and 15% HSA (best flowability).

Important bioactive molecules of erythrocytes in colorectal cancer patients after colectomy.

Formaldehyde (HCHO) and protoporphyrin, are in connection with redox homeostasis. Data show the importance of HCHO in proliferative as well as in apoptotic processes. Free protoporphyrin can be detected near the Zn-protoporphyrin in cancer and it has pro- and antioxidant forms depending on concentrations. The aim was to determine the amount of HCHO and protoporphyrin concentrations of erythrocytes in colorectal cancer after colectomy and to estimate redox homeostasis. Total 32 adult patients after 5-10 years of colectomy and 9 healthy volunteers were drawn into this study. Tumor markers, redox parameters, HbA1c, HCHO and protoporphyrin concentrations were measured. Erytrocyte HCHO was significantly lower in colectomysed patients, than in controls. Protoporphyrin concentration was low in patients, but in metastasis its concentration was significant. HbA1c correlated significantly with free radicals and decreased the antioxidant status of erythrocytes. HCHO and protoporphyrin concentrations of erythrocytes and the total scavenger capacity are very important indexes in cancer.

[Nutritional and antioxidant status of colorectal cancer patients]. / Colorectalis tumorban szenvedô betegek tápláltsági állapota és antioxidáns-státusza.

INTRODUCTION: Oxidative stress is one of the risk factors of colorectal carcinogenesis. In inflammatory reactions the activated leucocytes product mutagenic and mitogenic free radicals, hereby promoting tumor formation. Obesity, hyperlipidemia and hyperinsulinemia increases the energy supply of epithelial cells, thus leads to deregulation of mitochondrial electron transport chain. The latter leads to increased free radical production that causes troubles in cell cycle regulation, mutations, and unrestricted proliferation of damaged cells. AIM: Evaluation of some parameters of antioxidant and nutritional status in patients with benign or malignant colorectal neoplasm. METHODS: Assessment of nutrient intake, measurement of some anthropometric parameters (body height, body weight, waist, hip and arm circumference, waist/hip ratio), determination of serum prealbumin level, evaluation of the biomarkers of antioxidant status (superoxide dismutase and glutathione peroxidase activity, levels of uric acid and albumin, total antioxidant status, free radical scavenger capacity), determination the concentration of oxidated product and malondialdehyde. RESULTS: In patients with malignant tumor the dietary fiber, folate and vitamin A intake was under the optimal level, and the serum prealbumin concentration was lower than in patients with benign lesion. There was a high incidence of overweight and obesity among patients. Significant difference was found between diseased subjects and healthy controls in terms of the biomarkers of antioxidant status, such as free radical scavenger capacity, concentration of advanced oxidation protein products and malondialdehyde, glutathione peroxidase activity. CONCLUSIONS: The insufficient folate and vitamin A intake, the high incidence of overweight and obesity, and the abnormal values of the biomarkers of antioxidant status observed in the study groups seem to support the correlation between colorectal tumor, nutritional and antioxidant status.

Reduced antioxidant level and increased oxidative damage in intact liver lobes during ischaemia-reperfusion.

AIM: To determine whether increased blood flow of the liver can cause oxidative stress and hepatocyte damage, and to elaborate methods suitable for measuring the antioxidant defence during hepatic surgery on rat model. METHODS: In nembutal narcosis, the left lateral and the medial lobes of the liver were clipped for 45 min to make the total blood supply flow through the other lobes. Total antioxidant status, glutathione peroxidase and superoxide dysmutase activity, as well as the concentrations of diene conjugates and free sulphydril groups, H-donating ability and reducing power of the liver samples were determined. Chemiluminescent intensity of the liver was also measured. Metal ions (Al, Ca, Cu, Fe, Mg, Mn, Zn) and P and S concentrations of the liver were determined with an inductively coupled plasma optical emission spectrometer and Se content was measured by cathodic stripping voltammetry. RESULTS: Glutathione peroxidase and superoxide dysmutase activities of the liver decreased significantly in the hyperemia group compared to those observed in the sham operated group. The level of total antioxidant status was also significantly lower in the hyperemia group. H-donating ability, reducing power and free sulphydril group concentration showed the same tendency. A significant correlation (P<0.05) was found between the changes in non-specific antioxidant activities. This pointed to simultaneous activity of the antioxidant defence system. Al, Cu, Mn, Zn, and S were lower in the hyperemia group than in the sham operated group when the levels of Ca, Fe, Mg, Se and P ions were higher during hyperemia. CONCLUSION: Oxidative stress is one of the main factors for the injury of intact liver lobes during ischaemia-reperfusion.

[Methods of monitoring oxidation-reduction balance and its potential role in diagnostics]. / A szervezet redox-egyensúlyának vizsgálati módszerei, lehetséges szerepük a diagnosztikában.

Results of the latest investigations confirm that the injury of redox homeostasis of human organism can be the starting point of many diseases. The pathogenesis of these diseases, including atherosclerosis, diabetes mellitus, chronic liver diseases, renal failure, rheumatoid arthritis and neurodegenerative diseases could be cleared up more deeply by the investigation of parameters of oxidative stress and by the observation of their changes in connection with the different organ and tissue damages. It is well known, that individuals with lowered antioxidant defences may be at greater risk of developing diseases induced by free radicals. The goal of the authors is to direct attention to the possible role of some redox parameters in detecting of general health status of the human body and in the risk assessment of the different diseases. These measurements can perhaps help the clinician in determining optimal treatment and monitoring its effectiveness.

[Possibilities of monitoring oxidative damage and its clinical aspects]. / Az oxidatív károsodás monitorozásának lehetóségei, és a vizsgálatok klinikai vonatkozásai.

In their earlier work the authors reviewed some methods, which appeared to be suitable for monitoring the redox-status of the human organism and, therefore, may be applied under routine clinical laboratory circumstances. This possibility can lead to a new perspective to set up epidemiological studies in different populations in order to investigate connecting points between the manner of life, alimentary customs (especially consumption of antioxidants), and the risk of chronic or acute illnesses. In this review the authors surveyed different methods for the measurements of end products (lipids, proteins, nucleic acids) produced by cells and tissues through oxidative injury, caused by the free radicals. These methods have already served the work of scientists for many years, helping them to obtain experience about the pathomechanisms of different diseases. With the help of these measurements it could be possible to monitor the results of medical therapy or surgical treatments, or in the field of chronic illnesses e.g. diabetes, to predict the possible development of late complications.