Peroxidase Immobilized Cryogels for Phenolic Compounds Removal

Immobilized enzymes and cell systems: an approach to the removal of phenol and the challenges to incorporate nanoparticle-based technology

The presence of phenol in wastewater poses a risk to ecosystems and human health. The traditional processes to remove phenol from wastewater, although effective, have several drawbacks. The best alternative is the application of ecological biotechnology tools since they involve biological systems (enzymes and microorganisms) with moderate economic and environmental impact. However, these systems have a high sensitivity to environmental factors and high substrate concentrations that reduce their effectiveness in phenol removal. This can be overcome by immobilization-based technology to increase the performance of enzymes and bacteria. A key component to ensure successful immobilization is the material (polymeric matrices) used as support for the biological system. In addition, by incorporating magnetic nanoparticles into conventional immobilized systems, a low-cost process is achieved but, most importantly, the magnetically immobilized system can be recovered, recycled, and reused. In this review, we study the existing alternatives for treating wastewater with phenol, from physical and chemical to biological techniques. The latter focus on the immobilization of enzymes and microorganisms. The characteristics of the support materials that ensure the viability of the immobilization are compared. In addition, the challenges and opportunities that arise from incorporating magnetic nanoparticles in immobilized systems are addressed.

Injectable Cryogels Associate with Adipose-Derived Stem Cells for Cardiac Healing After Acute Myocardial Infarctions

Treatment of adipose-derived stem cells (ADSCs) provides support for novel methods of conveying baseline cell protein endothelial cells to promote acute myocardial infarction in gelatin sericin (GS) lamin-coated antioxidant systems (GS@L). The ratio of fixity modules, pores, absorption, and inflammation in the range of ka (65 ka), 149 ±39.8 μm, 92.2%, 42 ± 1.38, and 29 ± 1.9 were observed in the synthesized frames for GS. Herein, ADSC-GS@L was prepared, and the relevant substance for the development of cardiac regenerative applications was stable and physically chemical. In vitro assessments of ADSC-GS@L injectable cryogels established the enhanced survival rates of the cell and improved pro- angiogenic factors as well as pro-inflammatory expression, confirming the favorable outcomes of fractional ejections, fibro-areas, and vessel densities with reduced infraction dimensions. The novel ADSC-injecting cryogel method could be useful for successful heart injury therapies during acute myocardial infarction. Additionally, the method could be useful for successful heart injury therapies during coronary heart disease.

An accomplished procedure of horseradish peroxidase immobilization for removal of acid yellow 11 in aqueous solutions

Horseradish peroxidase (HRP) characteristics were improved by two techniques, Na-alginate entrapment and glutaraldehyde crosslinking prior to alginate entrapment, in order to enhance the stability, functionality and removal of dyes in waste water. Free, entrapped and crosslinked-entrapped enzymes were compared by activity assays, which indicated the optimum temperature is 25 °C and pH 4.0-5.0. Kinetics results showed that alginate entrapment and crosslinking prior to entrapment increased V_max and did not cause any significant decrease in K_m. The thermal resistance of the free enzyme was short-term, zero residual activity after 250 min, while the immobilized enzymes preserved more than 50% of their activity for 5 h at 60 °C. Immobilized HRP was resistant to methanol, ethanol, DMSO and THF. The storage stability of free HRP ended in 35 days whereas entrapped and crosslinked-entrapped HRPs had 87 and 92% residual activity at the 60th day, respectively. HRP was used in the decolorization of azo dye Acid yellow 11 and total decolorization (>99%) was obtained using crosslinked-entrapped HRP. Reusability studies presented the improvement that crosslinked-entrapped HRP reached 74% decolorization after 10 batches. The results demonstrated that the novel immobilized HRP can be used as an effective catalyst for dye degradation of industrial waste effluents.

Flow-Through Catalytic Reactors Based on Metal Nanoparticles Immobilized within Porous Polymeric Gels and Surfaces/Hollows of Polymeric Membranes

State-of-the-art of flow-through catalytic reactors based on metal nanoparticles immobilized within the pores of nano-, micro- and macrosized polymeric gels and in the surface or hollow of polymeric membranes is discussed in this mini-review. The unique advantages of continuous flow-through nanocatalysis over the traditional batch-type analog are high activity, selectivity, productivity, recyclability, continuous operation, and purity of reaction products etc. The methods of fabrication of polymeric carriers and immobilization technique for metal nanoparticles on the surface of porous or hollow structures are considered. Several catalytic model reactions comprising of hydrolysis, decomposition, hydrogenation, oxidation, Suzuki coupling and enzymatic reactions in the flow system are exemplified. Realization of “on-off” switching mechanism for regulation of the rate of catalytic process through controlling the mass transfers of reactants in liquid media with the help of stimuli-responsive polymers is demonstrated. Comparative analysis of the efficiency of different flow-through catalytic reactors for various reactions is also surveyed.