High catalytic performances of Pseudomonas fluorescens lipase adsorbed on a new type of cyclodextrin-based nanosponges

Nanosponge: A promising and intriguing strategy in medical and pharmaceutical Science

The complicated chemical reactions involved in the production of the newer drug delivery systems have mainly impeded efforts to build successful targeted drug delivery systems for a prolonged duration of time. Nanosponges, a recently created colloidal system, have the potential to overcome issues with medication toxicity, decreased bioavailability, and drug release over a wide area because they can be modified to work with both hydrophilic and hydrophobic types of drugs. Nanosponges are small sized with a three-dimensional network having a porous cavity. They can be prepared easily by crosslinking cyclodextrins with different compounds. Due to Cyclodextrin's outstanding biocompatibility, stability, and safety, a number of Cyclodextrin-based drug delivery systems have been developed promptly. The nanosponge drug delivery system possesses various applications in various ailments such as cancer, autoimmune diseases, theranostic applications, enhanced bioavailability, stability, etc. This review elaborates on benefits and drawbacks, preparation techniques, factors affecting their preparation, characterization techniques, applications, and most current developments in nanosponges.

Nanosponge Approach -A Plethora of Opportunities as a Promising Nanocarrier for Novel Drug Delivery

BACKGROUND

Nanotechnology is the need of the hour! The design of nanotechnologyaided carriers as a tool for the delivery of low solubility molecules offers a potential platform to overcome the issues of current clinical treatment and achieve good targeted release and bioaccessibility.

OBJECTIVE

Nanosponges (NS) encapsulate types of nanocarriers capable of carrying both lipophilic and hydrophilic substances. They are synthesized by mixing a solution of polyester, which is biodegradable, with cross-linkers. These tiny, porous structures are round-shaped, having multiple cavities wherein drugs can be housed to offer programmable release.

METHODS

The detailed literature review and patent search summarize the ongoing research on NS. Substances such as poorly soluble drugs, nutraceuticals, gases, proteins and peptides, volatile oils, genetic material, etc., can be loaded on these novel carriers, which are characterized using various analytical techniques. Target-specific drug delivery and controlled drug release are the advantages offered by NS, along with a myriad of other promising applications.

RESULTS

This review stresses the development of cyclodextrin-based NS, the synthetic methods and characterization of NS, along with factors affecting NS formation, their applications and information on the patented work in this area. NS are solid in character and can be formulated in various dosage forms, such as parenteral, topical, oral or inhalation.

CONCLUSION

Therefore, owing to their promising benefits over other nanocarriers in terms of drug loading, adaptability, sustainability, solubility and tailored release profile, NS is an immediate technological revolution for drug entrapment and as novel drug carriers.The authors expect that these fundamental applications of NS could help the researchers to develop and gain insight about NS in novel drug delivery applications.

Protein scaffolds: A tool for multi-enzyme assembly

The synthesis of complex molecules using multiple enzymes simultaneously in one reaction vessel has rapidly emerged as a new frontier in the field of bioprocess technology. However, operating different enzymes together in a single vessel limits their operational performance which needs to be addressed. With this respect, scaffolding proteins play an immense role in bringing different enzymes together in a specific manner. The scaffolding improves the catalytic performance, enzyme stability and provides an optimal micro-environment for biochemical reactions. This review describes the components of protein scaffolds, different ways of constructing a protein scaffold-based multi-enzyme complex, and their effects on enzyme kinetics. Moreover, different conjugation strategies viz; dockerin-cohesin interaction, SpyTag-SpyCatcher system, peptide linker-based ligation, affibody, and sortase-mediated ligation are discussed in detail. Various analytical and characterization tools that have enabled the development of these scaffolding strategies are also reviewed. Such mega-enzyme complexes promise wider applications in the field of biotechnology and bioengineering.

Stochastic Mechanochemical Description of a Bioinspired Polymerization Process

We present a theoretical investigation of a polymerization process catalyzed by an enzyme. A structural model of enzyme, sliding along the polymer chain as a Brownian particle, is proposed, and a stochastic approach is employed to describe the kinetics of the whole process. The key point of this work is the coupling mechanics/chemistry obtained by assuming that (1) some rates of chemical reaction depend on the position of the enzyme with respect to the polymer chain and (2) the potential energy and the friction coefficient in the Langevin equation depend on the chemical state of the polymerizing complex. We describe an algorithm for computing our stochastic model and a methodology to solve the Langevin equation numerically. We predict in particular: (1) the sudden arrest of the polymerization, (2) the decrease in the relative polydispersity with the increase in the length of the polymer chain, (3) the occurrence of four regimes, (4) the manifestation of the coupling mechanics/chemistry for one regime and (5) the possibility to evaluate the mechanical variables through classical chemical analysis. Although essentially devoted to the elongation phase, this work also briefly addresses the problem of phase termination and we propose a new device aimed at reducing the polydispersity of technical origin in actual polymerization processes.

Biodiesel Production via Trans-Esterification Using Pseudomonas cepacia Immobilized on Cellulosic Polyurethane

In this work, Pseudomonas cepacia lipase immobilized on cellulosic polyurethane was used as a catalyst for biodiesel production via trans-esterification reactions in order to provide cost-effective methods of enzyme recycling. The efficacy of the immobilized enzyme catalyst at low loading (6.2 wt %) and the effects of temperature, water content, and reaction time in model trans-esterification of glyceryl trioctanoate were investigated extensively. It was found that water was necessary for the reaction of glyceryl trioctanoate with ethanol to proceed. A high conversion of glyceryl trioctanoate (∼70%) was obtained at 35 °C, with only 5.0 wt % of water content over a reaction period of 12 h.

Combination of carbon nanotube and cyclodextrin nanosponge chemistry to develop a heterogeneous Pd-based catalyst for ligand and copper free C-C coupling reactions

Carbon nanotubes and cyclodextrin nanosponge were hybridized and used as a support for embedding Pd(0) nanoparticles and developing a novel and heterogeneous catalyst, Pd@CDNS-CNT, for promoting ligand and copper-free Sonogashira and Heck coupling reactions in aqueous media and mild reaction condition. Cyclodextrin nanosponge could contribute to catalysis through encapsulating the reagents and transferring them in the vicinity of Pd nanoparticles. The results established that the catalytic activity of Pd@CDNS-CNT was superior to those of Pd@CNT, Pd@CDNS and Pd@CNT + CDNS, indicating the synergism between the components of the hybrid system. Notably, various aryl halides including aryl iodide, bromide and chloride were useful substrates for the coupling reactions and affording the corresponding products in high to excellent yields in short reaction times. Moreover, the catalyst was recyclable up to six reaction runs with negligible Pd leaching.

Covalent immobilization of α-amylase on magnetic particles as catalyst for hydrolysis of high-amylose starch

Enzyme immobilized on magnetic particles can be used as efficient recoverable biocatalysts under strong magnetic response. To enable re-use of enzyme, modified Fe3O4 particles were used as carrier to immobilize α-amylase in this paper. Firstly, the surface of Fe3O4 particles were coated with amino groups by direct using TEOS (tetraethoxysilane) followed by treatment with APTES (3-aminopropyltriethoxysilane) and then carboxylated by reacting it with succinic anhydride. In addition, the effect of the immobilization condition on enzyme activity recovery and immobilization efficiency were investigated. The results showed that the optimal immobilization occurred under following conditions: pH 5.5, 40°C, enzyme concentration of 20mgmL(-1), reaction time for 36h. Using immobilized α-amylase as biocatalyst, the optimum pH and temperature for hydrolysis were observed to be 6.5 and 60°C. The kinetics of hydrolysis reaction were studied using Michaelis-Menten equation. The affinity constant (Km) and maximum reaction rate (vmax) of magnetic particles immobilization α-amylase (MPIA) was 0.543mgmL(-1) and 1.321mgmin(-1) compared to those of 0.377mgmL(-1) and 6.859mgmin(-1) of free enzyme. After immobilization, enzymatic activity, storage stability, thermo-stability, and reusability of MPIA were found superior to those of the free one. MPIA maintained 86% enzyme activity after 30 days and maintained 78% enzyme activity after recycling six times.

Structural and functional stabilization of protein entities: state-of-the-art

Within the context of biomedicine and pharmaceutical sciences, the issue of (therapeutic) protein stabilization assumes particular relevance. Stabilization of protein and protein-like molecules translates into preservation of both structure and functionality during storage and/or targeting, and such stabilization is mostly attained through establishment of a thermodynamic equilibrium with the (micro)environment. The basic thermodynamic principles that govern protein structural transitions and the interactions of the protein molecule with its (micro)environment are, therefore, tackled in a systematic fashion. Highlights are given to the major classes of (bio)therapeutic molecules, viz. enzymes, recombinant proteins, (macro)peptides, (monoclonal) antibodies and bacteriophages. Modification of the microenvironment of the biomolecule via multipoint covalent attachment onto a solid surface followed by hydrophilic polymer co-immobilization, or physical containment within nanocarriers, are some of the (latest) strategies discussed aiming at full structural and functional stabilization of said biomolecules.

Immobilization of Brassica oleracea chlorophyllase 1 (BoCLH1) and Candida rugosa lipase (CRL) in magnetic alginate beads: an enzymatic evaluation in the corresponding proteins

Enzymes have a wide variety of applications in diverse biotechnological fields, and the immobilization of enzymes plays a key role in academic research or industrialization due to the stabilization and recyclability it confers. In this study, we immobilized the Brassica oleracea chlorophyllase 1 (BoCLH1) or Candida rugosa lipase (CRL) in magnetic iron oxide nanoparticles-loaded alginate composite beads. The catalytic activity and specific activity of the BoCLH1 and CRL entrapped in magnetic alginate composite beads were evaluated. Results show that the activity of immobilized BoCLH1 in magnetic alginate composite beads (3.36±0.469 U/g gel) was higher than that of immobilized BoCLH1 in alginate beads (2.96±0.264 U/g gel). In addition, the specific activity of BoCLH1 beads (10.90±1.521 U/mg protein) was higher than that immobilized BoCLH1 in alginate beads (8.52±0.758 U/mg protein). In contrast, the immobilized CRL in magnetic alginate composite beads exhibited a lower enzyme activity (11.81±0.618) than CRL immobilized in alginate beads (94.83±7.929), and the specific activity of immobilized CRL entrapped in magnetic alginate composite beads (1.99±0.104) was lower than immobilized lipase in alginate beads (15.01±1.255). A study of the degradation of magnetic alginate composite beads immersed in acidic solution (pH 3) shows that the magnetic alginate composite beads remain intact in acidic solution for at least 6 h, indicating the maintenance of the enzyme catalytic effect in low-pH environment. Finally, the enzyme immobilized magnetic alginate composite beads could be collected by an external magnet and reused for at least six cycles.

Catalytic behavior of lipase immobilized onto congo red and PEG-decorated particles

Poly(ethylene glycol) (PEG)-decorated polystyrene (PS) nanoparticles with mean hydrodynamic diameter (D) and zeta–potential (ζ) of (286 ± 15) nm and (−50 ± 5) mV, respectively, were modified by the adsorption of Congo red (CR). The PS/PEG/CR particles presented D and ζ values of (290 ± 19) nm and (−36 ± 5) mV, respectively. The adsorption of lipase onto PS/PEG or PS/PEG/CR particles at (24 ± 1) °C and pH 7 changed the mean D value to (380 ± 20) and (405 ± 11) nm, respectively, and ζ value to (−32 ± 4) mV and (−25 ± 2) mV, respectively. The kinetic parameters of the hydrolysis of p-nitrophenyl butyrate were determined for free lipase, lipase immobilized onto PS/PEG and PS/PEG/CR particles. Lipase on PS/PEG/CR presented the largest Michaelis-Menten constant (K_M), but also the highest V_max and k_cat values. Moreover, it could be recycled seven times, losing a maximum 10% or 30% of the original enzymatic activity at 40 °C or 25 °C, respectively. Although lipases immobilized onto PS/PEG particles presented the smallest K_M values, the reactions were comparatively the slowest and recycling was not possible. Hydrolysis reactions performed in the temperature range of 25 °C to 60 °C with free lipases and lipases immobilized onto PS/PEG/CR particles presented an optimal temperature at 40 °C. At 60 °C free lipases and lipases immobilized onto PS/PEG/CR presented ~80% and ~50% of the activity measured at 40 °C, indicating good thermal stability. Bioconjugation effects between CR and lipase were evidenced by circular dichroism spectroscopy and spectrophotometry. CR molecules mediate the open state conformation of the lipase lid and favor the substrate approaching.

Improving the esterification activity of Pseudomonas fluorescens and Burkholderia cepacia lipases via cross-linked cyclodextrin immobilization

Improving activities: solid cross-linked β-cyclodextrin enzymes can remarkably improve thermal stability and enzyme activity as compared to commercial immobilized enzymes in esterification reactions (e.g., monostearin synthesis).

Parameters Affecting the Performance of Immobilized Enzyme

Enzyme immobilization has been investigated to improve lipase properties over the past few decades. Different methods and various carriers have been employed to immobilize enzyme. However, the application of enzymatic technology in large scale is rarely seen during the industrial process. The main obstacles are a high cost of the immobilization and the poor performance of immobilized lipase. This review focuses on the current status of enzyme immobilization, which aims to summarize the latest research on the parameters affecting the performance of immobilized enzyme. Particularly, the effect of immobilization methods, immobilization carriers, and enzyme loading has been discussed.

Nanosponges - a completely new nano-horizon: pharmaceutical applications and recent advances

In recent years, nanosponges (NS) have gained tremendous impetus in drug delivery through nanotechnology. Nanosponges are capable of providing solutions for several formulation related problems. Through this review, scientists working in the field of nanotechnology can have an insight into the techniques of preparation, characterization and applications of NS. Owing to their small size and porous nature they can bind poorly-soluble drugs within their matrix and improve their bioavailability. They can be crafted for targeting drugs to specific sites, prevent drug and protein degradation and prolong drug release in a controlled manner. This review attempts to elaborate different schemes of synthesis of NS and their characterization. Factors affecting drug loading and release have been enumerated. Due to their advantages, NS have not only been explored for their pharmaceutical applications but also have large popularity in allied sciences, especially in water purification.

Enhancement of the activity and enantioselectivity of lipase by sol-gel encapsulation immobilization onto β-cyclodextrin-based polymer

Candida rugosa lipase was encapsulated within a chemically inert sol-gel support prepared by polycondensation with tetraethoxysilane and octyltriethoxysilane in the presence of β-cyclodextrin-based polymer. The catalytic activity of the encapsulated lipases was evaluated both in the hydrolysis of p-nitrophenylpalmitate and the enantioselective hydrolysis of racemic Naproxen methyl ester. It has been observed that the percent activity yield of the encapsulated lipase was 65 U/g, which is 7.5 times higher than that of the covalently immobilized lipase. The β-cyclodextrin-based encapsulated lipases had higher conversion and enantioselectivity compared with covalently immobilized lipase. The study confirms an excellent enantioselectivity (E >300) for the encapsulated lipase with an enantiomeric excess value of 98% for S-naproxen.