Oriented multivalent silaffin-affinity immobilization of recombinant lipase on diatom surface: Reliable loading and high performance of biocatalyst

Microbial lipases are widely used biocatalysts; however, their functional surface immobilization should be designed for successful industrial applications. One of the unmet challenges is to develop a practical surface immobilization to achieve both high stability and activity of lipases upon the large loading. Herein, we present a silaffin-based multivalent design as a simple and oriented approach for Bacillus subtilis lipase A (LipA) immobilization on economic diatom biosilica matrix to yield highly-stable activity with reliable loading. Specifically, silaffin peptides Sil3H, Sil3K, and Sil3R, as monovalent or divalent genetic fusion tags, selectively immobilized LipA on biosilica surfaces. Sil3K peptide fusion to LipA termini most efficiently produced high catalytic activity upon immobilization. The activity was 70-fold greater than that of immobilized wild-type LipA. Compared to single fusion, the double Sil3K fusion displayed 1.7 higher enzymatic loading combined with high catalytic performances of LipA on biosilica surfaces. The multivalent immobilized LipA was distributed uniformly on biosilica surfaces. The biocatalyst was stable over a wide pH range with 98% retention activity after 10 reuses. The stabilized lipase fusion was compatible with laundry detergents, making it an attractive biocatalyst for detergent formulations. These findings demonstrate that multivalent surface immobilization is a plausible method for developing high-performance biocatalysts suitable for industrial biotechnological applications.

A review of sustainable biodiesel production using biomass derived heterogeneous catalysts

The production of biodiesel through chemical production processes of transesterification reaction depends on suitable catalysts to hasten the chemical reactions. Therefore, the initial selection of catalysts is critical although it is also dependent on the quantity of free fatty acids in a given sample of oil. Earlier forms of biodiesel production processes relied on homogeneous catalysts, which have undesirable effects such as toxicity, high flammability, corrosion, by-products such as soap and glycerol, and high wastewater. Heterogeneous catalysts overcome most of these problems. Recent developments involve novel approaches using biomass and bio-waste resource derived heterogeneous catalysts. These catalysts are renewable, non-toxic, reusable, offer high catalytic activity and stability in both acidic and base conditions, and show high tolerance properties to water. This review work critically reviews biomass-based heterogeneous catalysts, especially those utilized in sustainable production of biofuel and biodiesel. This review examines the sustainability of these catalysts in literature in terms of small-scale laboratory and industrial applications in large-scale biodiesel and biofuel production. Furthermore, this work will critically review natural heterogeneous biomass waste and bio-waste catalysts in relation to upcoming nanotechnologies. Finally, this work will review the gaps identified in the literature for heterogeneous catalysts derived from biomass and other biocatalysts with a view to identifying future prospects for heterogeneous catalysts.

Nanomaterial conjugated lignocellulosic waste: cost-effective production of sustainable bioenergy using enzymes

The demand for novel and renewable sources of energy has increased as a result of rapid population growth, limited sources of bioenergy, and environmental pollution, caused by excessive use of fossil fuels. The need to meet future energy demands have motivated researchers to search for alternative and sustainable sources of energy. The bioconversion of lignocellulosic waste (agricultural and food waste) into biofuels shows competitive promises. Lignocellulosic waste is easily accessible and has a large enzyme system that can be immobilised onto nano-matrices. Consequently, resulting in higher biofuel production and process efficiency. However, the excessive production cost of the current procedures, which involve physical, chemical, and enzymatic reactions, is limited. The use of nanomaterials has recently been shown to concentrate lignocellulosic waste, therefore, reviewing the quest for efficient production of sustainable and cost-effective development of bioenergy from lignocellulosic wastes. This review paper explores the advanced strategies of using nanobiotechnology to combine enzyme-conjugated nanosystems for the cost-effective production of sustainable bioenergy solutions. This research will help to develop an inexpensive, eco-friendly technology for biofuels production and also help overcome the environmental burden of lignocellulosic waste worldwide.

Biological Properties of the Aggregated Form of Chitosan Magnetic Nanoparticle

BACKGROUND/AIM

Chitosan-coated iron oxide nanoparticles (Chi-NP) have gained attention because of their biocompatibility, biodegradability, low toxicity and targetability under magnetic field. In this study, we investigated various biological properties of Chi-NP.

MATERIALS AND METHODS

Chi-NP was prepared by mixing magnetic NP with chitosan FL-80. Particle size was determined by scanning and transmission electron microscopes, cell viability by MTT assay, cell cycle distribution by cell sorter, synergism with anticancer drugs by combination index, PGE₂ production in human gingival fibroblast was assayed by ELISA.

RESULTS

The synthetic process of Chi-NP from FL-80 and magnetic NP increased the affinity to cells, up to the level attained by nanofibers. Upon contact with the culture medium, Chi-NP instantly formed aggregates and interfered with intracellular uptake. Aggregated Chi-NP did not show cytotoxicity, synergism with anticancer drugs, induce apoptosis (accumulation of subG1 cell population), protect the cells from X-ray-induced damage, nor affected both basal and IL-1β-induced PGE₂ production.

CONCLUSION

Chi-NP is biologically inert and shows high affinity to cells, further confirming its superiority as a scaffold for drug delivery.

Application of Nanocellulose Derivatives as Drug Carriers; A Novel Approach in Drug Delivery

BACKGROUND

The production of nanocellulose for drug delivery systems has achieved increased attention in the past decade. High capacity for swelling and absorption of the liquid phase, high flexibility in creating different derivatives, economical cost, and ease of access to the primary source, all of these properties have encouraged researchers to use nanocellulose and its derivatives as a high-performance drug carrier.

OBJECTIVE

The recent progress summary of cellulose-based nanocarriers designing and practical approaches in drug delivery.

METHODS

We conducted a literature review on the development of the nanocellulose and its derivatives as a high-performance drug carrier.

RESULTS

In this review, we have attempted to present the latest advances in cellulose modifications for the design of pharmaceutical nanocarriers. At first, cellulose properties and structural classification of nanocellulose were introduced. Then, focusing on medical applications, some efforts and laboratory trials in cellulose-based nano designing were also discussed. The findings demonstrate the benefits of nanocellulose in drug delivery and its potential for modifying by adding functional groups to enhance drug delivery efficiency. Due to the physical and chemical properties of cellulose and its high flexibility to interact with other compounds, a broad perspective can be imagined in the diverse research and novel forms of nanocarriers.

CONCLUSION

The cellulose nanocarriers can be considered as an attractive platform for researchers to design new structures of pharmaceutical carriers and increase the efficiency of these nanocarriers in drug delivery for the treatment of diseases such as cancer.

Different strategies for the lipase immobilization on the chitosan based supports and their applications

Immobilized enzymes have received incredible interests in industry, pharmaceuticals, chemistry and biochemistry sectors due to their various advantages such as ease of separation, multiple reusability, non-toxicity, biocompatibility, high activity and resistant to environmental changes. This review in between various immobilized enzymes focuses on lipase as one of the most practical enzyme and chitosan as a preferred biosupport for lipase immobilization and provides a broad range of studies of recent decade. We highlight several aspects of lipase immobilization on the surface of chitosan support containing various types of lipase and immobilization techniques from physical adsorption to covalent bonding and cross-linking with their benefits and drawbacks. The recent advances and future perspectives that can improve the present problems with lipase and chitosan such as high-price of lipase and low mechanical resistance of chitosan are also discussed. According to the literature, optimization of immobilization methods, combination of these methods with other techniques, physical and chemical modifications of chitosan, co-immobilization and protein engineering can be useful as a solution to overcome the mentioned limitations.

One-Step Reinforcement and Deacidification of Paper Documents: Application of Lewis Base—Chitosan Nanoparticle Coatings and Analytical Characterization

To delay acidification and deterioration during natural aging, deacidification and reinforcement of paper manuscripts have been the most important technologies to prolong the life of objects. Herein, a novel approach for the conservation of paper manuscripts is proposed using chitosan nanoparticles as Lewis base that leads to both deacidification and strengthening of paper in one-step. Chitosan nanoparticles were prepared through physical ball grinding method and characterized via scanning electron microscopy (SEM), X-ray diffraction (XRD), laser particle size analyzer (LPSA), Fourier transform infrared spectroscopy (FTIR), and atomic force microscope (AFM). To evaluate the resistance of chitosan nanoparticle coating, the mechanical properties of paper after artificial aging were evaluated using dry heat and hygrothermal accelerated aging methods. The SEM, EDX, and X-ray Photoelectron Spectroscopy (XPS) were used to analyze the interaction mechanism between chitosan and Shuxuan paper. The results show that the coated paper had superior durability with respect to pH, tensile strength, and folding endurance. There was a presence of protonated amines in the form of ammonium salts due to ionic bindings with free H+ in the acidified paper, and the remaining –NH2 could be used as a base reserve. Finally, the resulting coated papers displayed good antibacterial properties.

Chitosan-alginate nanoparticles as effective oral carriers to improve the stability, bioavailability, and cytotoxicity of curcumin diethyl disuccinate

Curcumin diethyl disuccinate (CDD) is an ester prodrug of curcumin that has better chemical stability in phosphate buffer (pH 7.4) and anticancer activities against MDA-MB-231 human breast cancer cells and Caco-2 cells than curcumin. However, a major drawback of CDD is its poor water solubility and low bioavailability in the gastrointestinal tract. To overcome these problems, a nanoformulation was developed using chitosan/alginate nanoparticles (CANPs) under the optimal condition as previously derived by statistical optimization. The CDD-loaded CANPs (CDD-CANPs) were found to exhibit good stability after exposure to simulated digestive fluids and ultraviolet light, and a sustained-release profile of CDD in the simulated digestive and body fluids. The in vitro release pattern fitted well to the Peppas-Sahlin model, indicating that the release of CDD was mainly governed by diffusion. Compared to free CDD, the CDD-CANPs showed better stability, bioaccessibility, bioavailability, cellular uptake, and cytotoxicity against HepG2 cells.

A Review on Bio-Based Catalysts (Immobilized Enzymes) Used for Biodiesel Production

The continuous increase of the world’s population results in an increased demand for energy drastically from the industrial and domestic sectors as well. Moreover, the current public awareness regarding issues such as pollution and overuse of petroleum fuel has resulted in the development of research approaches concerning alternative renewable energy sources. Amongst the various options for renewable energies used in transportation systems, biodiesel is considered the most suitable replacement for fossil-based diesel. In what concerns the industrial application for biodiesel production, homogeneous catalysts such as sodium hydroxide, potassium hydroxide, sulfuric acid, and hydrochloric acid are usually selected, but their removal after reaction could prove to be rather complex and sometimes polluting, resulting in increases on the production costs. Therefore, there is an open field for research on new catalysts regarding biodiesel production, which can comprise heterogeneous catalysts. Apart from that, there are other alternatives to these chemical catalysts. Enzymatic catalysts have also been used in biodiesel production by employing lipases as biocatalysts. For economic reasons, and reusability and recycling, the lipases urged to be immobilized on suitable supports, thus the concept of heterogeneous biocatalysis comes in existence. Just like other heterogeneous catalytic materials, this one also presents similar issues with inefficiency and mass-transfer limitations. A solution to overcome the said limitations can be to consider the use of nanostructures to support enzyme immobilization, thus obtaining new heterogeneous biocatalysts. This review mainly focuses on the application of enzymatic catalysts as well as nano(bio)catalysts in transesterification reaction and their multiple methods of synthesis.

Exploration of Chitinous Scaffold-Based Interfaces for Glucose Sensing Assemblies

: The nanomaterial-integrated chitinous polymers have promoted the technological advancements in personal health care apparatus, particularly for enzyme-based devices like the glucometer. Chitin and chitosan, being natural biopolymers, have attracted great attention in the field of biocatalysts engineering. Their remarkable tunable properties have been explored for enhancing enzyme performance and biosensor advancements. Currently, incorporation of nanomaterials in chitin and chitosan-based biosensors are also widely exploited for enzyme stability and interference-free detection. Therefore, in this review, we focus on various innovative multi-faceted strategies used for the fabrication of biological assemblies using chitinous biomaterial interface. We aim to summarize the current development on chitin/chitosan and their nano-architecture scaffolds for interdisciplinary biosensor research, especially for analytes like glucose. This review article will be useful for understanding the overall multifunctional aspects and progress of chitin and chitosan-based polysaccharides in the food, biomedical, pharmaceutical, environmental, and other diverse applications.

Use of Glucose Oxidase Immobilized on Magnetic Chitosan Nanoparticles in Probiotic Drinking Yogurt

The aim of this study was to investigate the effect of glucose oxidase (GOX) immobilized on magnetic chitosan nanoparticles (MCNP) on the viability of probiotic bacteria and the physico-chemical properties of drinking yogurt. Different concentrations (0, 250, and 500 mg/kg) of free and immobilized GOX were used in probiotic drinking yogurt samples. The samples were stored at 4°C for 21 d. During storage, reduction of the number of probiotic bacteria in the samples with enzyme was lower than the control sample (without enzyme). The sample containing 500 mg/kg immobilized enzyme had the highest number of Bifidobacterium lactis and Lactobacillus acidophilus. The samples containing immobilized enzyme had lower acidity than other samples. Moreover, moderate proteolytic activity and enough contents of flavor compounds were observed in these samples. It can be concluded that use of immobilized GOX is economically more feasible because of improving the viability of probiotic bacteria and the physico-chemical characteristics of drinking yogurt.