Construction of a Mesoporous Ceria Hollow Sphere/Enzyme Nanoreactor for Enhanced Cascade Catalytic Antibacterial Therapy.

Nanozyme has been regarded as one of the antibacterial agents to kill bacteria via a Fenton-like reaction in the presence of H2O2. However, it still suffers drawbacks such as insufficient catalytic activity in near-neutral conditions and the requirement of high H2O2 levels, which would minimize the side effects to healthy tissues. Herein, a mesoporous ceria hollow sphere/enzyme nanoreactor is constructed by loading glucose oxidase in the mesoporous ceria hollow sphere nanozyme. Due to the mesoporous framework, large internal voids, and high specific surface area, the obtained nanoreactor can effectively convert the nontoxic glucose into highly toxic hydroxyl radicals via a cascade catalytic reaction. Moreover, the generated glucose acid can decrease the localized pH value, further boosting the peroxidase-like catalytic performance of mesoporous ceria. The generated hydroxyl radicals could damage severely the cell structure of the bacteria and prevent biofilm formation. Moreover, the in vivo experiments demonstrate that the nanoreactor can efficiently eliminate 99.9% of bacteria in the wound tissues and prevent persistent inflammation without damage to normal tissues in mice. This work provides a rational design of a nanoreactor with enhanced catalytic activity, which can covert glucose to hydroxyl radicals and exhibits potential applications in antibacterial therapy.

Glucose oxidase and polydopamine functionalized iron oxide nanoparticles: combination of the photothermal effect and reactive oxygen species generation for dual-modality selective cancer therapy.

Cancer cells possess some inherent characteristics, such as glucose-dependence and intolerance to heat and exogenous reactive oxygen species (ROS). In this study, a strategy has been developed to target these vulnerable weaknesses of cancer cells using glucose oxidase (GOx) and polydopamine (PDA) functionalized iron oxide nanoparticles (Fe3O4@PDA/GOx NPs). PDA is first deposited on the surfaces of iron oxide NPs through self-polymerization, and then GOx is covalently linked with PDA upon mixing the enzyme and Fe3O4@PDA under alkaline conditions. In this system, the PDA layer along with iron oxide NPs serves as a photothermal transfer material converting near infrared (NIR) radiation into heat. The covalently linked GOx can competitively consume glucose and spontaneously generate ROS H2O2 that can be further converted by the iron oxide NPs into more toxic ˙OH, inducing apoptosis of cancer cells. The selective toxicity of Fe3O4@PDA/GOx NPs on cancer cells is demonstrated both in vitro and in vivo. In particular, a single injection rather than multiple doses results in significant suppression of tumors, and does not induce apparent histological lesions in the 4T1 tumor-bearing Balb/c mice. The versatility of the functionalization strategy reported in this study will contribute to developing efficient therapies for selective cancer treatment.

[New approaches in surgical treatment of acute paraproctitis].

The results of treatment of 77 patients, ageing 18-71 yrs old, for an acute paraproctitis in 2010-2014 yrs were analyzed. A preventive puncture-flush enzymosanation of purulent foci, using immobilized bacterial proteinases (imozimase), metrogyl P in conjunction with low-intensive laser irradiation have permitted to conduct the optimal preoperative preparation of patients, to improve their state, to reduce the local inflammatory reactions intensity significantly.

Anti-inflammatory and antifibrotic effects of a combination of spiperone and immobilized hyaluronidase on partially reversible and irreversible toxic pneumofibrosis.

The possibility of boosting antifibrotic activity of testicular hyaluronidase immobilized on polyethylene oxide with spiperone was studied on the bleomycin models of a single (partially reversible pneumofibrosis) and repeated (irreversible pneumofibrosis) injuries to the alveolar epithelium in C57Bl/6 mice. The antifibrotic effect was more pronounced after successive treatment with immobilized hyaluronidase and spiperone than after individual treatment with each of the compounds: no collagen deposition in the parenchyma of bleomycin-damaged lungs was found. The decrease in inflammatory cell (lymphocytes, macrophages, neutrophils, plasma cells) infiltration of the alveoli and alveolar tracts interstitium in mice treated by immobilized hyaluronidase and spiperone did not differ from the anti-inflammatory effect of spiperone monotherapy.

Enzymosomes with surface-exposed superoxide dismutase: in vivo behaviour and therapeutic activity in a model of adjuvant arthritis.

Acylated Superoxide Dismutase (Ac-SOD) enzymosomes, liposomal enzymatic systems expressing catalytic activity in the intact form, were previously characterized. The main scope of the present work was to investigate the biological behaviour of Ac-SOD inserted in the lipid bilayer of liposomes, in comparison with SOD located in the aqueous compartment of liposomes. Two types of liposomes were used: conventional liposomes presenting an unmodified external surface and long circulating liposomes coated with poly (ethylene glycol) (PEG). Liposomal formulations of Ac-SOD and SOD were prepared and labelled with indium-111 and their in vivo fate compared. Data obtained led us to the conclusion that, for liposomes coated with PEG the in vivo fate was not influenced by the insertion of Ac-SOD in the lipid bilayers. The potential therapeutic effect of Ac-SOD enzymosomes was compared with SOD liposomes in a rat model of adjuvant arthritis. A faster anti-inflammatory effect was observed for Ac-SOD enzymosomes by monitoring the volume of the inflamed paws. The present results allowed us to conclude that Ac-SOD enzymosomes are nano-carriers combining the advantages of expressing enzymatic activity in intact form and thus being able to exert therapeutic effect even before liposomes disruption, as well as acting as a sustained release of the enzyme.

Anti-tumoral effect of native and immobilized bovine serum amine oxidase in a mouse melanoma model.

Bovine serum amine oxidase (BSAO) oxidatively deaminates polyamines containing primary amine groups, spermidine and spermine, to form the cytotoxic products hydrogen peroxide and aldehyde(s). Polyamines are present at elevated levels in many tumor tissues. The aims of the study were to evaluate the anti-tumoral activities of native and immobilized BSAO in mouse melanoma and also to determine the mechanism of tumor cell death. C57BL mice received a subcutaneous injection of B16 melanoma cells to induce formation of tumors, prior to antitumor treatments with native and immobilized BSAO. The enzyme was immobilized in a poly(ethylene glycol) (PEG) biocompatible matrix. Antitumor treatments consisted of a single injection of enzyme into the tumor. When immobilized BSAO (2.5mU) was injected into the tumor, there was a marked decrease of 70% of the tumor growth. This was compared with a decrease of only 32% of tumor size when the same amount of native BSAO was administered. The type of cell death was analysed in tumors that were treated with native or immobilized BSAO. When tumors were treated with immobilized BSAO, there was induction of a high level of apoptosis (around 70%), compared to less than 10% with the native enzyme. Apoptotic cell death was assessed by nuclear chromatin condensation using Hoechst staining and labelling of externalized phosphatidylserine using Annexin V. However, native BSAO, probably due to a burst of cytotoxic products, induced a high level of necrosis of about 40%, compared to less than 10% with immobilized BSAO. In conclusion, the advantage is that immobilized BSAO can act by allowing the slow release of cytotoxic products, which induces tumor cell death by apoptosis rather than necrosis.

[Possibilities of the use of immobilized proteolytic enzyme immozymase in tuberculosis]. / Vozmozhnosti primeneniia immobilizovannogo proteoliticheskogo fermenta immozimazy vo ftiziatrii.

The paper summarises the experience gained in the use of immozymase in tuberculous patients to advance the disease diagnosis and treatment. Immozymase proved valuable in obtaining sputum enriched with M. tuberculosis in patients who were previously considered noncarriers. M. tuberculosis became detectable in 28.3% of them. Immozymase instillations of the urethra before its massage for stimulation of prostatic secretion led to getting secretion in all the patients (0.35 ml, on the average). Immuzymase inhalations were used in the treatment of purulent bronchitis in patients with destructive pulmonary tuberculosis in conservative and preoperative regimens. Postoperative immozymase inhalations promoted prevention of pleuropulmonary complications. Open treatment of the caverns with immozymase after cavernotomy shortens the treatment duration. Positive results were also reached in the treatment of pleural empyema.

Antitumor activity of an immobilized peroxidase system against murine Ehrlich ascites is mediated by the immune system.

Earlier studies have shown that a mixture of glucose oxidase and a peroxidase exerts a tumoricidal effect on rats bearing Novikoff hepatomas when the enzyme mixture is injected intraperitoneally. The enzyme mixture was shown to be nontoxic when injected into healthy animals at levels up to 600 times the therapeutic dose. In the present study, we have evaluated the possibility that the host immune defense system may be involved in the antitumor activity of the peroxidase system, using the murine Ehrlich ascites tumor as the target. The results revealed that the antitumor activity of the peroxidase system is absent in tumor-bearing animals whose immune system has been compromised by whole body gamma-irradiation or by an induced selenium deficiency. The peroxidase system was also found to be inactive in tumor-bearing mice whose immune system was suppressed by the administration of cyclosporin A as well as in athymic (nu/nu) mice. These results indicate that T lymphocytes may directly or indirectly be involved in the in vivo antitumor activity of the peroxidase system. This could explain the observed high selectivity toward tumor cells by the enzyme system in vivo and its lack of toxicity in healthy animals.

[High molecular weight L-asparaginase derivatives based on a water-soluble carboxymethyl cellulose: biological properties]. / Vysokomolekuliarnye proizvodnye L-asparaginazy na osnove vodorastvorimoi karboksimetiltselliulozy: biologicheskie svoistva.

L-asparaginase, covalently bound with water-soluble CM-cellulose, exhibited the elevated antileukemic activity in mice with inoculated lymphoid leukemia L5178y as compared with the native enzyme. The antileukemic activity of the immobilized enzyme was shown to depend on the content of the polymer bound with the enzyme; the polymer amount may be altered during the enzyme modification. The prolonged effect of immobilized L-asparaginase was observed in rabbit circulation.

[Effect of terrilytin on the activity of nonspecific resistance factors during immunization with staphylococcal anatoxin and staphylococcal infection]. / Vliianie terrilitina na aktivnost' faktorov nespetsificheskoi rezistentnosti pri immunizatsii stafilokokkovom anatoksinom i infitsirovanii stafilokokkom.

Terrilytin and immobilized terrilytin enhance the activity and intensity of phagocytosis and increase the concentration of lysozyme in nonimmunized animals. Both preparations increase the production of antibodies to staphylococcal alpha-hemolysin, the titers of beta-lysins, the activity and intensity of the phagocytosis of bacterial cells by peripheral blood leukocytes in animals immunized with staphylococcal toxoid and challenged with live staphylococcal culture. In healthy animals terrilytin and immobilized terrilytin induce an increase in total proteolytic activity and in the activity of alpha-1-antitrypsin and alpha-2-macroglobulin, decreased as the result of staphylococcal infection.