MOF-Immobilized Two-in-One Engineered Enzymes Enhancing Activity of Biocatalytic Cascade for Tumor Therapy.

Biocatalytic systems based on enzyme cascade reactions have attracted growing interest in the field of biocatalytic medicine. However, it is a major challenge to reasonably construct enzyme cascade reactions with high stability, selectivity, and catalytic efficiency for the in vivo biocatalytic application. Herein, two-in-one engineered glucose oxidase (GOx-Fe0 ) is fabricated by a biomineralization strategy, through which a nanozyme (Fe0 NP) is anchored within the inner cavity of GOx. Then, GOx-Fe0 is immobilized in a pH-sensitive metal-organic framework (MOF) zeolitic imidazolate framework-8 (ZIF-8) to establish a stable and effective MOF-immobilized two-in-one engineered enzyme, GOx-Fe0 @ZIF-8. In vitro studies show that GOx-Fe0 @ZIF-8 exhibits excellent stability and high pH/glucose selectivity, and the shorter spacing between cascade enzymes can increase the cascade throughput and effectively improve the reaction efficiency of the enzyme cascade. In vivo experiments exhibit that GOx-Fe0 @ZIF-8 solves the instability and systemic toxicity of free enzymes, and achieves deep tumor penetration and significant chemodynamic therapeutic efficacy through a pH/glucose-selective enzyme cascade reaction in tumor site. Taken together, such an orchestrated enzyme engineering strategy can effectively improve enzyme stability, selectivity, and enzyme cascade reaction efficiency via chemical transformations, and also provide a promising strategy for the application of biocatalytic cascade reactions in vivo.

Synergistic Multimodal Cancer Therapy Using Glucose Oxidase@CuS Nanocomposites.

Multimodal nanotherapeutic cancer treatments are widely studied but are often limited by their costly and complex syntheses that are not easily scaled up. Herein, a simple formulation of glucose-oxidase-coated CuS nanoparticles was demonstrated to be highly effective for melanoma treatment, acting through a synergistic combination of glucose starvation, photothermal therapy, and synergistic advanced chemodynamic therapy enabled by near-infrared irradiation coupled with Fenton-like reactions that were enhanced by endogenous chloride.

A cancer cell membrane-encapsulated MnO2 nanoreactor for combined photodynamic-starvation therapy.

We demonstrate a MnO2-based nanoreactor to achieve continuous oxygen generation and efficient conversion from glucose to singlet oxygen for combined photodynamic-starvation 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.

Cloning and expression of L-asparaginase from Bacillus tequilensis PV9W and therapeutic efficacy of Solid Lipid Particle formulations against cancer.

L-asparaginase, a therapeutic involved in cancer therapy, from Bacillus tequilensis PV9W (ansA gene) was cloned and over expressed in Escherichia coli BL21 (DE3), achieved the aim of maximizing the yield of the recombinant enzyme (6.02 ± 1.77 IU/mL) within 12 h. The native L-asparaginase of B. tequilensis PV9W was encapsulated using solid lipid particles by hot lipid emulsion method, which is reported for first time in this study. Subsequently, the lipid encapsulated L-asparaginase (LPE) was characterized by SEM, UV-Vis spectroscopy, FT-IR, SDS-PAGE and its thermo stability was also analyzed by TGA. Further characterization of LPE revealed that enzyme was highly stable for 25 days when stored at 25 °C, showed high pH (9) tolerance and longer trypsin half-life (120 min). In addition, the cytotoxic ability of LPE on HeLa cells was highly enhanced compared to the native L-asparaginase from Bacillus tequilensis PV9W. Moreover, better kinetic velocity and lower Km values of LPE aided to detect L-asparagine in cell extracts by Differential Pulse Voltammetry (DPV) method. The LPE preparation also showed least immunogenic reaction when tested on normal macrophage cell lines. This LPE preparation might thus pave way for efficient drug delivery and enhancing the stability of L-asparaginase for its therapeutic applications.

Use of an In-line Digestive Cartridge With Enteral Nutrition Improves the Weight Trajectory of 2 Children With Cystic Fibrosis Complicated by Another Medical Diagnosis.

This clinical observation describes the enteral nutrition (EN) management of 2 toddlers at high nutrition risk due to cystic fibrosis (CF), exocrine pancreatic insufficiency, and comorbid medical conditions. The first case report describes a boy with severe malabsorption after intestinal resection. The second case report reviews a boy with CF and neuroblastoma. When pancreatic enzyme replacement therapy with EN was not effective or appropriate, use of an in-line digestive cartridge was initiated. While using the digestive cartridge, both children showed improvements in their anthropometric measures. This observation reviews the nutrition management throughout their clinical course and describes the use of a digestive cartridge with EN.

Enzymes as Immunotherapeutics.

Enzymes are attractive as immunotherapeutics because they can catalyze shifts in the local availability of immunostimulatory and immunosuppressive signals. Clinical success of enzyme immunotherapeutics frequently hinges upon achieving sustained biocatalysis over relevant time scales. The time scale and location of biocatalysis are often dictated by the location of the substrate. For example, therapeutic enzymes that convert substrates distributed systemically are typically designed to have a long half-life in circulation, whereas enzymes that convert substrates localized to a specific tissue or cell population can be more effective when designed to accumulate at the target site. This Topical Review surveys approaches to improve enzyme immunotherapeutic efficacy via chemical modification, encapsulation, and immobilization that increases enzyme accumulation at target sites or extends enzyme half-life in circulation. Examples provided illustrate "replacement therapies" to restore deficient enzyme function, as well as "enhancement therapies" that augment native enzyme function via supraphysiologic doses. Existing FDA-approved enzyme immunotherapies are highlighted, followed by discussion of emerging experimental strategies such as those designed to enhance antitumor immunity or resolve inflammation.

[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.

Antifibrotic activity of hyaluronidase immobilized on polyethylenoxide under conditions of bleomycin-induced pneumofibrosis.

Hyaluronidase immobilized on polyethylenoxide obtained by electron bean synthesis was administered intranasally and intravenously to C57Bl/6 mice after intratracheal bleomycin and the enzyme effects on the development of pneumofibrosis in animals were studied. Intranasal immobilized hyaluronidase prevented connective tissue growth in the lungs exposed to bleomycin and virtually did not modulate the infiltration of the alveolar and alveolar duct interstitium by inflammatory cells (lymphocytes, macrophages, neutrophils, plasma cells). The antifibrotic effect developed sooner after intranasal inoculation of immobilized hyaluronidase and was more pronounced than after intranasal native hyaluronidase. Intravenous injection of immobilized hyaluronidase did not modify the inflammatory process and deposition of collagen fibrils in the lung parenchyma in pneumofibrosis.

Pegloticase and the patient with treatment-failure gout.

Gout is an inflammatory arthritis characterized by sudden, painful inflammation. Gout can affect any joint in an asymmetric distribution. Gouty attacks may be isolated or can be followed by years of recurrent flares. Over time, elevated serum urate levels and tophaceous deposits can lead to deformity and disability from underlying bony erosion. The concept of 'treatment-failure gout' describes a unique population that has been either unable to tolerate allopurinol or who have not experienced normalization of serum urate levels on allopurinol. It is estimated that approximately 1-1.5% of the estimated 3-8 million people with gout in the USA have treatment-failure gout. Pegloticase is an US FDA-approved intravenous medication that is a mammalian recombinant uricase conjugated to monomethoxy polyethylene glycol. Two recent Phase III trials have found pegloticase to be effective in the management of treatment-failure gout. These studies also highlight safety concerns regarding the drug's immunogenicity.

Mechanisms for hepatoprotective effects of hyaluronidase immobilized by the nanotechnology method of electron-beam synthesis.

Immobilized hyaluronidase (nanotechnology method of electron-beam synthesis) exhibited high hepatoprotective activity on the model of Cl4-induced hepatitis. This agent produced anticholestatic, anti-inflammatory, and antisclerotic effects. These effects were shown to accompany stimulation of multipotent bone marrow precursors, mobilization of these cells into the peripheral blood, and cell migration to the target organ increasing the number of parenchymal progenitor cells in the liver. The mechanisms for targeted migration of progenitor cells suggest a decrease in SDF-1 production by bone marrow stromal cells and increase in the synthesis of this factor by microenvironmental cells of the liver tissue.

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.

A Phase I-II trial of polyethylene glycol-conjugated L-asparaginase in patients with multiple myeloma.

BACKGROUND: Multiple myeloma remains an incurable disease. New agents are needed to improve therapy for patients with this disease. Previous investigators evaluated in vitro sensitivity of myeloma cells to polyethylene glycol-conjugated L-asparaginase (PEG-L-asparaginase) using the human tumor clonogenic assay. Of the 19 myeloma samples evaluated, 63% were inhibited at 0.075 IU/mL, and 74% were inhibited at 0.75 IU/mL. PEG-L-asparaginase is a form of Escherichia coli-derived L-asparaginase that is bound covalently to polyethylene glycol. Compared with the native form, it has a longer half-life and is less likely to cause allergic reactions. METHODS: The authors conducted a Phase I-II trial using PEG-L-asparaginase as a single agent in patients with recurrent and/or refractory multiple myeloma. RESULTS: Twenty-two patients received a median of two doses of PEG-L-asparaginase. In the 17 patients who are evaluable for response, a complete response was observed in one patient after four doses, and stable disease was observed in eight patients. Progression of disease was the reason for termination from study in the remaining eight patients. The median survival was 31.7 months, with four patients who were alive at 72 months after the start of therapy. Grade 3-4 toxicity was noted by the PEG-L-asparaginase 2000 mg/m(2) level. Severe allergic reactions were noted only at the highest dose level. CONCLUSIONS: Current data suggest that the maximal tolerated dose for single agent PEG-L-asparaginase in relapse/refractory multiple myeloma patients is 1000 mg/m(2) every 4 weeks. We could not identify any correlation between dose, plasma level and response. In this advanced group of patients we noted stable disease and/or response in 52% of evaluable patients. PEG-L-asparaginase has lower tolerance when used in the standard dosage as a single agent in this group of patients. We therefore recommend further studying of PEG-L-asparaginase dose of 1000 mg/m(2) on alternate weeks with steroids and/or other immune modulators.

[Progress in researches on anti-tumor agent L-asparaginase for treatment of leukemia].

L-asparaginase is a very effective anti-tumor agent. To take the most advantage of enzyme treatment method, the natural L-asparaginase could be chemically modified, entrapped or immobilized into/onto other carriers. The extracorporeal shunt system with immobilized enzyme reactor deserves to receive special attention. It provides an entirely new idea for leukemia treatment and is proved to be very prospective in the future leukemia cure.

Immobilized proteinases in the treatment of diffuse purulent peritonitis.

In vitro experiments on fibrin films using purulent exudate from the abdominal cavity of rats with experimental peritonitis demonstrate the fibrinolytic effect of bacterial proteinases immobilized on a polymeric matrix. The application of Imozimaza in the complex treatment of experimental peritonitis by the way of intraperitoneal lavage resulted in reliable lowering of mortality, due to the lysis of fibrinopurulent abdominal contents and better contact between antibacterial agents and peritonitis pathogens. In the clinic, prolonged abdominal proteolysis was applied to 44 patients with postoperative diffuse purulent peritonitis of >24 h duration. Under the conditions of programmable relaparotomy, intraperitoneal Imozimaza infusion led (as in in vitro tests) to the lysis of fibrinopurulent masses, which contained micro-organisms of an order higher than exudate. It was accompanied by increase in the drainage efficacy, absence of fragmentation of abdominal contents and absence of secondary abscesses. The use of Imozimaza on the background of complex antibacterial treatment and combined homeostatic therapy resulted in lowering of mortality from 65.8% to 27.3%. Complications and contra-indications for Imozimaza use in diffuse purulent peritonitis were not registered.

Highly efficient immobilization of phospholipase A2 and its biomedical applications.

A new method for the immobilization of phospholipase A2 (PLA2) has been developed to enhance the activity retention of immobilized PLA2. When PLA2 from the venom of Agkistrodon piscivorus piscivorus was pretreated with 4-nitro-3-octanoyl-oxybenzoic acid to acylate epsilon-amino groups of two lysines (Lys-7 and Lys-10) and the resulting acylated enzyme was covalently coupled onto carbonyldiimidazole-activated cross-linked agarose beads, the immobilized acylated enzyme showed high retention of activity toward various aggregated phospholipids. Toward densely packed phospholipid bilayers, such as large unilamellar vesicles of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, the immobilized acylated A. p. piscivorus PLA2 was 25-fold more active than the soluble A. p. piscivorus PLA2. The general applicability of our immobilization protocol was demonstrated by the high retention of activity achieved for the immobilized acylated PLA2 from the venom of Naja naja naja. In particular, full activity retention of the immobilized acylated A. p. piscivorus PLA2 toward phospholipids on the surface of human low density lipoproteins suggests its potential usefulness in a newly developed PLA2-based therapy for hypercholesterolemia.

Prognostic factors for treatment of malignant lymphoma in dogs.

Pretreatment characteristics of 138 dogs with malignant lymphoma were analyzed to determine prognostic factors associated with outcome (ie, complete response rate, time to relapse after complete response, survival time). Dogs were all treated for 10 weeks, using a standard induction chemotherapy protocol, and were then given asparaginase weekly. Once the disease became progressive, second-line chemotherapy was instituted. Age, sex, weight, clinical stage, performance grade, immunophenotype, and malignancy grade assigned according to the National Cancer Institute's Working Formulation were not associated with complete response rate. However, malignancy grade assigned according to the Kiel classification was found to be associated with complete response rate; dogs with high-grade malignancies had a significantly higher complete response rate than did dogs with low-grade malignancies. By means of multivariate analysis, clinical stage and immunophenotype were found to be prognostic factors for time to relapse (among dogs that had had a complete response) and survival time. In addition, malignancy grade assigned according to the Kiel classification was found to be a prognostic factor for time to relapse; whereas, malignancy grade assigned according to the Working Formulation was determined to be a prognostic factor for survival time.