Virus-Derived Peptides for Hepatic Enzyme Delivery.

Recently, a lipopeptide derived from the hepatitis B virus (HBV) large surface protein has been developed as an HBV entry inhibitor. This lipopeptide, called MyrcludexB (MyrB), selectively binds to the sodium taurocholate cotransporting polypeptide (NTCP) on the basolateral membrane of hepatocytes. Here, the feasibility of coupling therapeutic enzymes to MyrB was investigated for the development of enzyme delivery strategies. Hepatotropic targeting shall enable enzyme prodrug therapies and detoxification procedures. Here, horseradish peroxidase (HRP) was conjugated to MyrB via maleimide chemistry, and coupling was validated by SDS-PAGE and reversed-phase HPLC. The specificity of the target recognition of HRP-MyrB could be shown in an NTCP-overexpressing liver parenchymal cell line, as demonstrated by competitive inhibition with an excess of free MyrB and displayed a strong linear dependency on the applied HRP-MyrB concentration. In vivo studies in zebrafish embryos revealed a dominating interaction of HRP-MyrB with scavenger endothelial cells vs xenografted NTCP expressing mammalian cells. In mice, radiolabeled 125I-HRP-MyrBy, as well as the non-NTCP targeted control HRP-peptide-construct (125I-HRP-alaMyrBy) demonstrated a strong liver accumulation confirming the nonspecific interaction with scavenger cells. Still, MyrB conjugation to HRP resulted in an increased and NTCP-mediated hepatotropism, as revealed by competitive inhibition. In conclusion, the model enzyme HRP was successfully conjugated to MyrB to achieve NTCP-specific targeting in vitro with the potential for ex vivo diagnostic applications. In vivo, target specificity was reduced by non-NTCP-mediated interactions. Nonetheless, tissue distribution experiments in zebrafish embryos provide mechanistic insight into underlying scavenging processes indicating partial involvement of stabilin receptors.

Biomimetic microbioreactor-supramolecular nanovesicles improve enzyme therapy of hepatic cancer.

A novel biomimetic nanovesicle-loaded supramolecular enzyme-based therapeutics has been developed. Here, using a biomimetic lipid-D-α-tocopherol polyethylene glycol succinate (TPGS) hybrid semi-permeable membrane, cyclodextrin supramolecular docking, metal-ion-aided coordination complexing, we combined multiple functional motifs into a single biomimetic microbioreactor-supramolecular nanovesicle (MiSuNv) that allowed effective transport of arginine deiminase (ADI) to hepatic tumor cells to enhance arginine depletion. We compared two intercalated enzyme-carrying supermolecular motifs mainly comprising of 2-hydroxypropyl-ß-cyclodextrin and sulfobutyl-ether-ß-cyclodextrin, the only two cyclodextrin derivatives approved for injection by the United States Food and Drug Administration. The ADI-specific antitumor effects were enhanced by TPGS (one constituent of MiSuNv, having synergistic antitumor effects), as ADI was separated from adverse external environment by a semi-permeable membrane and sequestered in a favorable internal microenvironment with an optimal pH and metal-ion combination. ADI@MiSuNv contributed to cell cycle arrest, apoptosis and autophagy through the enhanced efficacy of enzyme treatment against Hep3B xenograft tumors in rats.

Enzyme Therapy: Current Challenges and Future Perspectives.

In recent years, enzymes have risen as promising therapeutic tools for different pathologies, from metabolic deficiencies, such as fibrosis conditions, ocular pathologies or joint problems, to cancer or cardiovascular diseases. Treatments based on the catalytic activity of enzymes are able to convert a wide range of target molecules to restore the correct physiological metabolism. These treatments present several advantages compared to established therapeutic approaches thanks to their affinity and specificity properties. However, enzymes present some challenges, such as short in vivo half-life, lack of targeted action and, in particular, patient immune system reaction against the enzyme. For this reason, it is important to monitor serum immune response during treatment. This can be achieved by conventional techniques (ELISA) but also by new promising tools such as microarrays. These assays have gained popularity due to their high-throughput analysis capacity, their simplicity, and their potential to monitor the immune response of patients during enzyme therapies. In this growing field, research is still ongoing to solve current health problems such as COVID-19. Currently, promising therapeutic alternatives using the angiotensin-converting enzyme 2 (ACE2) are being studied to treat COVID-19.

Dendrimers as Non-Viral Vectors in Gene-Directed Enzyme Prodrug Therapy.

Gene-directed enzyme prodrug therapy (GDEPT) has been intensively studied as a promising new strategy of prodrug delivery, with its main advantages being represented by an enhanced efficacy and a reduced off-target toxicity of the active drug. In recent years, numerous therapeutic systems based on GDEPT strategy have entered clinical trials. In order to deliver the desired gene at a specific site of action, this therapeutic approach uses vectors divided in two major categories, viral vectors and non-viral vectors, with the latter being represented by chemical delivery agents. There is considerable interest in the development of non-viral vectors due to their decreased immunogenicity, higher specificity, ease of synthesis and greater flexibility for subsequent modulations. Dendrimers used as delivery vehicles offer many advantages, such as: nanoscale size, precise molecular weight, increased solubility, high load capacity, high bioavailability and low immunogenicity. The aim of the present work was to provide a comprehensive overview of the recent advances regarding the use of dendrimers as non-viral carriers in the GDEPT therapy.

A Retrospective Review of an Off-label Bromelain-based Selective Enzymatic Debridement (Nexobrid®) in the Treatment of Deep, Partial, and Full Thickness Burns and Hard to Heal Wounds.

BACKGROUND: Rapid and selective bromelain-based enzymatic debridement provides a non-surgical alternative for the eschar removal in deep burns, which allows for early debridement of large surface areas, accurate evaluation of burn and wound depth, and the need for skin grafting. OBJECTIVES: To evaluate the efficacy of application of a bromelain-based selective enzymatic debridement (Nexobrid®) beyond the manufacturer's guidelines for use in burns > 48 hours as well as chemical, electrical, and pediatric burns, and chronic wounds. METHODS: This retrospective review included records collected between January 2017 and April 2019, from male and female patients aged 8 months to 99 years with deep burns or wounds treated with bromelain-based selective enzymatic debridement. RESULTS: Of the 33 patients who received the bromelain-based selective enzymatic debridement agent beyond the manufacturer's guidelines, 25 (76%) were observed to have successful debridement of the eschar, 8 (24%) were observed to have little effect on the burn eschar. Sixteen required further surgery after debridement. Clinical data on the use of bromelain-based selective enzymatic debridement agents are limited, but these results suggest the capacity to effectively debride burns > 48 hours (late presentation burns), use for pediatrics and for chemical and electrical burns, and apply to hard to heal full thickness chronic wounds. CONCLUSIONS: Bromelain-based selective enzymatic debridement was found to be an effective treatment modality beyond the recommended guidelines including late presentation burns and chronic wounds. This debridement method warrants further consideration when making clinical decisions concerning burn and wound care.

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.

Molecular basis and current strategies of therapeutic arginine depletion for cancer.

Renewed interest in the use of therapeutic enzymes combined with an improved knowledge of cancer cell metabolism, has led to the translation of several arginine depletion strategies into early phase clinical trials. Arginine auxotrophic tumors are reliant on extracellular arginine, due to the downregulation of arginosuccinate synthetase or ornithine transcarbamylase-key enzymes for intracellular arginine recycling. Engineered arginine catabolic enzymes such as recombinant human arginase (rh-Arg1-PEG) and arginine deiminase (ADI-PEG) have demonstrated cytotoxicity against arginine auxotrophic tumors. In this review, we discuss the molecular events triggered by extracellular arginine depletion that contribute to tumor cell death.

Effect of systemic enzymotherapy on Cesarean section scar healing.

OBJECTIVES: The aim of our study was to monitor changes in the healing of Caesarean section scars in patients using systemic enzymotherapy in comparison with patients not treated with systemic enzymotherapy (Wobenzym). METHODS: A prospective cohort study was conducted in 60 primiparous women delivered by CS. We compared the following outcomes: scar thickness after the Caesarean section, dehiscence risk coefficient (DRC), severity of the Caesarean section scar defect, uterine cavity dilation, post-operative pain, C-reactive protein level and febrility. RESULTS: The scar thickness 6 weeks after CS was significantly greater in the group of patients taking Wobenzym (7.1±0.9 mm; mean ± SD) than in the patients without Wobenzym (5.3±0.7 mm) (p = 0.01). Severe Caesarean section scar defects were observed in 1/30 (3.3%) Wobenzym users and in 5/30 (16.7%) patients who did not use Wobenzym, with no statistically significant difference (p = 0.195). CONCLUSION: Despite the percentage of patients with a severe CS scar defect being apparently lower in the group treated with Wobenzym, the difference did not reach statistical significance due to the small size of the study population.

[Effect of immunotherapy on the cellular immunity in patients with cervical cancer].

UNLABELLED: For the last thirty years immunotherapy has become an integral part of treatment of some cancers. The most effective approach in this context would be the use of complex immunostimulatory factors including tumor antigen in different forms, interleukins that stimulate differentiation. BACKGROUND: The aim of the study was to compare cellular immune response on specific and combined immunotherapy in patients with cervical cancer. PATIENTS AND METHODS: 76 cervical cancer patients undergoing combined radiotherapy were included into the study. Plus to basic radiation treatment two types of immunotherapy was performed: first--autolymphocytes reinfusion after in vitro incubation with tumor antigen (tumor tissue homogenate) and interleukin-2, second--combination of above mentioned immunotherapy, interleukin-2 and systemic enzyme. RESULTS: This has resulted in increase of cellular immunity parameters in the main group with combined immunotherapy an excess of cells with killer activity to ensure an effective antitumor immune response and, accordingly, the clinical efficacy of specific methods and adoptive immunotherapy in patients with cervical cancer. CONCLUSION: Immunotherapy usage in the form of a preparation of interleukin-2 and a system enzymotherapy in a combination with a specific immunotherapy is possible. This way of treatment is recommended in cases of decreasing of cellular immunity indicators.

Opportunities for nanomaterials in enzyme therapy.

In recent years, enzyme therapy strategies have rapidly evolved to catalyze essential biochemical reactions with therapeutic potential. These approaches hold particular promise in addressing rare genetic disorders, cancer treatment, neurodegenerative conditions, wound healing, inflammation management, and infectious disease control, among others. There are several primary reasons for the utilization of enzymes as therapeutics: their substrate specificity, their biological compatibility, and their ability to generate a high number of product molecules per enzyme unit. These features have encouraged their application in enzyme replacement therapy where the enzyme serves as the therapeutic agent to rectify abnormal metabolic and physiological processes, enzyme prodrug therapy where the enzyme initiates a clinical effect by activating prodrugs, and enzyme dynamic or starving therapy where the enzyme acts upon host substrate molecules. Currently, there are >20 commercialized products based on therapeutic enzymes, but approval rates are considerably lower than other biologicals. This has stimulated nanobiotechnology in the last years to develop nanoparticle-based solutions that integrate therapeutic enzymes. This approach aims to enhance stability, prevent rapid clearance, reduce immunogenicity, and even enable spatio-temporal activation of the therapeutic catalyst. This comprehensive review delves into emerging trends in the application of therapeutic enzymes, with a particular emphasis on the synergistic opportunities presented by incorporating enzymes into nanomaterials. Such integration holds the promise of enhancing existing therapies or even paving the way for innovative nanotherapeutic approaches.

Modeling of pharmacokinetics of cocaine in human reveals the feasibility for development of enzyme therapies for drugs of abuse.

A promising strategy for drug abuse treatment is to accelerate the drug metabolism by administration of a drug-metabolizing enzyme. The question is how effectively an enzyme can actually prevent the drug from entering brain and producing physiological effects. In the present study, we have developed a pharmacokinetic model through a combined use of in vitro kinetic parameters and positron emission tomography data in human to examine the effects of a cocaine-metabolizing enzyme in plasma on the time course of cocaine in plasma and brain of human. Without an exogenous enzyme, cocaine half-lives in both brain and plasma are almost linearly dependent on the initial cocaine concentration in plasma. The threshold concentration of cocaine in brain required to produce physiological effects has been estimated to be 0.22±0.07 µM, and the threshold area under the cocaine concentration versus time curve (AUC) value in brain (denoted by AUC2(∞)) required to produce physiological effects has been estimated to be 7.9±2.7 µM·min. It has been demonstrated that administration of a cocaine hydrolase/esterase (CocH/CocE) can considerably decrease the cocaine half-lives in both brain and plasma, the peak cocaine concentration in brain, and the AUC2(∞). The estimated maximum cocaine plasma concentration which a given concentration of drug-metabolizing enzyme can effectively prevent from entering brain and producing physiological effects can be used to guide future preclinical/clinical studies on cocaine-metabolizing enzymes. Understanding of drug-metabolizing enzymes is key to the science of pharmacokinetics. The general insights into the effects of a drug-metabolizing enzyme on drug kinetics in human should be valuable also in future development of enzyme therapies for other drugs of abuse.

A prospective, randomized, double-blind, placebo-controlled clinical trial comparing the efficacy of systemic enzyme therapy for edema control in orthognathic surgery using ultrasound scan to measure facial swelling.

PURPOSE: To evaluate the effectiveness of systemic enzyme therapy for the control of edema in patients who undergo bimaxillary orthognathic surgery. MATERIALS AND METHODS: Thirty patients were included in this double-blinded, randomized, control trial. Before surgery, each patient was allotted a code (study or control group). Nine anthropometric points were selected. Thickness of the soft tissue at each of these points was measured using an ultrasound device. These measurements were performed on the day before surgery and 1, 5, and 15 days after surgery. The study group was given a twice-daily dose of systemic enzyme therapy from the first postoperative day for 5 days; the control group was given placebo. The percentage of difference in the thickness of the soft tissue was calculated at each of the 9 points on postoperative days 1, 5, and 15. These data were analyzed and compared using the Mann-Whitney test. RESULTS: The statistical evaluation showed a significant difference in soft tissue thickness between the 2 groups, especially on days 5 and 15, at most assessed points. CONCLUSION: The results of this study suggest that systemic enzyme therapy significantly decreases postoperative edema in orthognathic surgery, precluding long-term corticosteroid use.

Celiac disease: advances in treatment via gluten modification.

Celiac disease (CD) is an autoimmune enteropathy that occurs in genetically susceptible individuals carrying the prerequisite genetic markers HLA DQ2 or DQ8. These genetic markers are present in approximately 30% of the population, and the worldwide prevalence of CD is estimated to be approximately 1%-2%. Currently a gluten-free diet is the only treatment for CD, but novel therapies aimed at gluten modification are underway. This review will discuss gluten-based therapies including wheat alternatives and wheat selection, enzymatic alteration of wheat, oral enzyme supplements, and polymeric binders as exciting new therapies for treatment of CD.

Facial-muscle weakness, speech disorders and dysphagia are common in patients with classic infantile Pompe disease treated with enzyme therapy.

Classic infantile Pompe disease is an inherited generalized glycogen storage disorder caused by deficiency of lysosomal acid α-glucosidase. If left untreated, patients die before one year of age. Although enzyme-replacement therapy (ERT) has significantly prolonged lifespan, it has also revealed new aspects of the disease. For up to 11 years, we investigated the frequency and consequences of facial-muscle weakness, speech disorders and dysphagia in long-term survivors. Sequential photographs were used to determine the timing and severity of facial-muscle weakness. Using standardized articulation tests and fibreoptic endoscopic evaluation of swallowing, we investigated speech and swallowing function in a subset of patients. This study included 11 patients with classic infantile Pompe disease. Median age at the start of ERT was 2.4 months (range 0.1-8.3 months), and median age at the end of the study was 4.3 years (range 7.7 months -12.2 years). All patients developed facial-muscle weakness before the age of 15 months. Speech was studied in four patients. Articulation was disordered, with hypernasal resonance and reduced speech intelligibility in all four. Swallowing function was studied in six patients, the most important findings being ineffective swallowing with residues of food (5/6), penetration or aspiration (3/6), and reduced pharyngeal and/or laryngeal sensibility (2/6). We conclude that facial-muscle weakness, speech disorders and dysphagia are common in long-term survivors receiving ERT for classic infantile Pompe disease. To improve speech and reduce the risk for aspiration, early treatment by a speech therapist and regular swallowing assessments are recommended.

The past, present, and future of enzyme-based therapies.

Enzyme-based therapeutics (EBTs) have the potential to tap into an almost unmeasurable amount of enzyme biodiversity and treat myriad conditions. Although EBTs were some of the first biologics used clinically, the rate of development of newer EBTs has lagged behind that of other biologics. Here, we review the history of EBTs, and discuss the state of each class of EBT, their potential clinical advantages, and the unique challenges to their development. Additionally, we discuss key remaining technical barriers that, if addressed, could increase the diversity and rate of the development of EBTs.

Synthesis and characterization of a novel chitosan based E. coli cytosine deaminase nanocomposite for potential application in prodrug enzyme therapy.

Cytosine deaminase is a non-mammalian enzyme of widespread interest for prodrug enzyme therapy due to its ability to convert prodrug 5-fluorocytosine into anticancer drug 5-fluorouracil. Cytosine deaminase enzyme has been purified to homogeneity from E. coli K-12 MTCC 1302 strain. K(m) values for cytosine and 5-fluorocytosine were found to be 0.26 mM and 1.82 mM, respectively. We developed a chitosan-entrapped cytosine deaminase nanocomposite. Atomic force microscopy and transmission electron microscopy images showed an elongated sphere shape nanocomposite with an average size of 80 nm diameter. Fourier transform infrared spectroscopy and X-ray diffraction results confirmed gel formation and entrapment of cytosine deaminase within the nanocomposite. Sustained release of cytosine deaminase from the nanocomposite up to one week depicted its potential implication in prodrug inducted enzyme therapy.

[Systemic enzymotherapy in the combined treatment of infectious endocarditis in drug addicts].

The aim of this study was to elucidate effects of systemic enzymotherapy on the clinical course of infectious endocarditis and the frequency of thromboembolic complications in drug addicts compared with controls. Another objective was to develop an optimal regime of enzymotherapy depending on the severity of the disease. Inclusion of wobenzyme in the combined treatment of infectious endocarditis permitted to accelerate the achievement of clinical improvement, normalize blood rheologic characteristics, reduce severity of intoxication and systemic inflammation, decrease the frequency of septic thromboembolia of the pulmonary artery.

Microbial Enzymes used in Prodrug Activation for Cancer Therapy: Insights and Future Perspectives.

Enzyme prodrug therapy has gained momentum in recent years due to its ability to improve therapeutic index (benefits versus toxic side-effects) and efficacy of chemotherapy in cancer treatment. Inactive prodrugs used in this system are converted into active anti-cancerous drugs by enzymes, specifically within the tumor cells. This therapy involves three components namely prodrug, enzyme and gene delivery vector. Past reports have clearly indicated that the choice of enzyme used is the major determinant for the success of this therapy. Generally, enzymes from nonhuman sources are employed to avoid off-target toxicity. Exogenous enzymes also give better control to the clinician regarding the calibration of treatment by site-specific initiation. Amongst these exo-enzymes, microbial enzymes are preferred due to their high productivity, stability and ease of manipulation. The present review focuses on the commonly used microbial enzymes, particularly cytosine deaminase, nitroreductase, carboxypeptidase, purine nucleoside phosphorylase in prodrug activation therapy. Various aspects viz. source of the enzymes, types of cancer targeted, mode of action and efficacy of the enzyme/prodrug system, efficient vectors used and recent research developments of each of these enzymes are comprehensively elaborated. Further, the results of the clinical trials and various strategies to improve their clinical applicability are also discussed.