Preparation of a highly stable drug carrier by efficient immobilization of human serum albumin (HSA) on drug-loaded magnetic iron oxide nanoparticles

Advances in chemically modified HSA as a multifunctional carrier for transforming cancer therapy regimens

Human serum albumin (HSA) is a versatile, biodegradable, biocompatible, non-toxic, and non-immunogenic protein nanocarrier, making it an ideal platform for developing advanced drug delivery systems. These properties have garnered significant attention in utilizing HSA nanoparticles for the safe and efficient delivery of chemotherapeutic agents. HSA-based nanoparticles can be surface-modified with various ligands to enable tumor-targeted drug delivery, enhancing therapeutic specificity and efficacy. Furthermore, the multifunctionality of HSA nanoparticles offers promising strategies to overcome challenges in cancer therapy, including poor bioavailability, off-target toxicity, and drug resistance. This review highlights the structural features of HSA, explores its diverse modifications to improve drug-binding affinity and targeting ability, and discusses its potential as a multifunctional carrier in oncology. By summarizing the latest advances in HSA modification techniques and applications, this review provides a comprehensive perspective on the future of protein-based drug delivery systems in tumor therapy.

Development of a Novel Human Serum Albumin-Based Tool for Effective Drug Discovery: The Investigation of Protein Quality and Immobilization

The binding ability of human serum albumin (HSA) on active pharmaceutical ingredients (APIs) is one of the most important parameters in the early stages of drug discovery. In this study, an immobilized HSA-based tool was developed for the rapid and easy in vitro screening of API binding. The work explored the serious incompleteness in the identification of HSA used for in vitro screening published in the last five years. To mitigate this problem, a comprehensive analysis and immobilization studies were performed on the most used HSA types. Serious differences in the colloidal stability of HSAs and their API binding ability on a selected set of APIs were observed. HSAs were immobilized on magnetic nanoparticles with glutardialdehyde (GDA) or cyclohexyl-diglycidyl ether (CDGE) linkers, which have never been used for HSA immobilization before. The HSA-MNP-CDGE complexes achieved a higher immobilization yield and preserved API binding ability; however, the esterase-like enzymatic activity of HSA reduced significantly.

Revolutionizing Alzheimer's treatment: Harnessing human serum albumin for targeted drug delivery and therapy advancements

Alzheimer's disease (AD) is a neurodegenerative disorder initiated by amyloid-beta (Aβ) accumulation, leading to impaired cognitive function. Several delivery approaches have been improved for AD management. Among them, human serum albumin (HSA) is broadly employed for drug delivery and targeting the Aβ in AD owing to its biocompatibility, Aβ inhibitory effect, and nanoform, which showed blood-brain barrier (BBB) crossing ability via glycoprotein 60 (gp60) receptor and secreted protein acidic and rich in cysteine (SPARC) protein to transfer the drug molecules in the brain. Thus far, there is no previous review focusing on HSA and its drug delivery system in AD. Hence, the reviewed article aimed to critically compile the HSA therapeutic as well as drug delivery role in AD management. It also delivers information on how HSA-incorporated nanoparticles with surfaced embedded ligands such as TAT, GM1, and so on, not only improve BBB permeability but also increase neuron cell targetability in AD brain. Additionally, Aβ and tau pathology, including various metabolic markers likely BACE1 and BACE2, etc., are discussed. Besides, the molecular interaction of HSA with Aβ and its distinctive forms are critically reviewed that HSA can segregate Zn(II) and Cu(II) metal ions from Aβ owing to high affinity. Furthermore, the BBB drug delivery challenges in AD are addressed. Finally, the clinical formulation of HSA for the management of AD is critically discussed on how the HSA inhibits Aβ oligomer and fibril, while glycated HSA participates in amyloid plaque formation, i.e., β-structure sheet formation. This review report provides theoretical background on HSA-based AD drug delivery and makes suggestions for future prospect-related work.

Improving the selective naked-eye detection of COVID-19 mediated by simultaneously using three different target oligonucleotides coated on plasmonic AuNPs/hexagonal Ag@AuNPs

The localized surface plasmon resonance (LSPR) phenomenon provides a versatile property in biosensor technology. This uncommon feature was utilized to produce a homogeneous optical biosensor to detect COVID-19 by the naked-eye readout. In this work, we synthesized two types of plasmonic nanoparticles: (i) AuNPs and (ii) hexagonal core-shell nanoparticles-Au shell on AgNPs (Au@AgNPs). We report herein the development of two colorimetric biosensors employing the efficient targeting and the binding ability for three regions of the COVID-19 genome, that is, S-gene, N-gene and E-gene, at the same time. Two AuNPs and Ag@AuNPs individually coated with three different targets oligonucleotide sequence (TOs) (AuNPs-TOs-mix and Ag@AuNPs-TOs-mix) for simultaneous detection of S-gene, N-gene and E-gene of the COVID-19 virus, using the LSPR and naked-eye methods in the laboratory and biological samples. The target COVID-19 genome RNA detected using the AuNPs-TOs-mix and Ag@AuNPs-TOs-mix can achieve the same sensitivity. The detection ranges by the AuNPs-TOs-mix and Ag@AuNPs-TOs-mix are both sufficiently improved in equal amounts in comparison to any of the AuNPs-TOs and Ag@AuNPs-TOs. The sensitivity of the current COVID-19 biosensors were 94% and 96% based on the number of positive samples detected for AuNPs-TOs-mix and Ag@AuNPs-TOs-mix, respectively. Moreover, all the real-time PCR confirmed negative samples obtained the same results by the biosensor; accordingly, the specificity of this approach got to 100%. The current study reports a selective, reliable, reproducible and visual 'naked-eye' detection of COVID-19, devoid of the requirement of any sophisticated instrumental techniques.Communicated by Ramaswamy H. Sarma.

Target protein identification of andrographolide based on isomer approach

The target identification of natural products is one of the most challenging issues in the standardized application of traditional Chinese medicine. It is widely recognized that magnetic nanoparticles (MNPs) could function as a tool that capture the target proteins of active molecule. However, the false positives caused by non-specific adsorption should not be ignored. Here, we reported a functionalized MNPs technique that could enrich the target proteins of andrographolide (AG) based on isomers approach. We designed and characterized MNPs and isomers of AG. The combination of the two could be used as an ideal coupling, which provides a feasible method for the target proteins enrichment of AG. In addition, the target proteins were identified by HPLC-MS/MS. Moreover, bioinformatics analysis and systematic computational dockings were performed to search for the interactions between target proteins and AG. Six inflammation-related proteins, including CD4, IKBKB, PKN1, PKN2, YWHAB and YWHAH were proved to be the anti-inflammatory targets of AG. All of the results indicated this integrated system could benefit target identification of bioactive natural products.

Magnetic Nanoparticles for Protein Separation and Purification

Proteins are essential for various functions such as brain activity and muscle contraction in humans. Even though food is a source of proteins, the bioavailability of proteins in most foods is usually limited due to matrix interaction with other biomolecules. Thus, it is essential to extract these proteins and provide them as a nutraceutical supplement to maintain protein levels and avoid protein deficiency. Hence, protein purification and extraction from natural sources are highly significant in biomedical applications. Chromatography, crude mechanical disruption, use of extractive chemicals, and electrophoresis are some of the methods applied to isolate specific proteins. Even though these methods possess several advantages, they are unable to extract specific proteins with high purity. A suitable alternative is the use of nanoparticles, which can be beneficial in protein purification and extraction. Notably, magnetic iron and iron-based nanoparticles have been employed in protein extraction processes and can be reused via demagnetization due to their magnetic property, smaller size, morphology, high surface-to-volume ratio, and surface charge-mediated property. This chapter is a summary of various magnetic nanoparticles (MNPs) that can be used for the biomolecular separation of proteins.

How can nanomicelle-curcumin modulate aluminum phosphide-induced neurotoxicity?: Role of SIRT1/FOXO3 signaling pathway

Aluminum phosphide (ALP) is among the most significant causes of brain toxicity and death in many countries. Curcumin (CUR), a major turmeric component, is a potent protective agent against many diseases, including brain toxicity. This study aimed to examine the probable protection potential of nanomicelle curcumin (nanomicelle-CUR) and its underlying mechanism in a rat model of ALP-induced brain toxicity. A total of 36 Wistar rats were randomly divided into six groups (n = 6) and exposed to ALP (2 mg/kg/day, orally) + CUR or nanomicelle-CUR (100 mg/kg/day, orally) for 7 days. Then, they were anesthetized, and brain tissue samples were dissected to evaluate histopathological alterations, oxidative stress biomarkers, gene expression of SIRT1, FOXO1a, FOXO3a, CAT and GPX in brain tissue via hematoxylin and eosin (H&E) staining, biochemical and enzyme-linked immunosorbent assay (ELISA) methods and Real-Time PCR analysis. CUR and nanomicelle-CUR caused significant improvement in ALP-induced brain damage by reducing the MDA levels and induction of antioxidant capacity (TTG, TAC and SOD levels) and antioxidant enzymes (CAT, GPX), modulation of histopathological changes and up-regulation of gene expression of SIRT1 in brain tissue. It was concluded that nanomicelle-CUR treatment ameliorated the harmful effects of ALP-induced brain toxicity by reducing oxidative stress. Therefore, it could be considered a suitable therapeutic choice for ALP poisoning.

Nanoparticles Containing Oxaliplatin and the Treatment of Colorectal Cancer

BACKGROUND

Colorectal cancer (CRC) is a highly widespread malignancy and ranks as the second most common cause of cancer-related mortality.

OBJECTIVE

Cancer patients, including those with CRC, who undergo chemotherapy, are often treated with platinum- based anticancer drugs such as oxaliplatin (OXA). Nevertheless, the administration of OXA is associated with a range of gastrointestinal problems, neuropathy, and respiratory tract infections. Hence, it is necessary to devise a potential strategy that can effectively tackle these aforementioned challenges. The use of nanocarriers has shown great potential in cancer treatment due to their ability to minimize side effects, target drugs directly to cancer cells, and improve drug efficacy. Furthermore, numerous studies have been published regarding the therapeutic efficacy of nanoparticles in the management of colorectal cancer.

METHODS

In this review, we present the most relevant nanostructures used for OXA encapsulation in recent years, such as solid lipid nanoparticles, liposomes, polysaccharides, proteins, silica nanoparticles, metal nanoparticles, and synthetic polymer-carriers. Additionally, the paper provides a summary of the disadvantages and limits associated with nanoparticles.

RESULTS

The use of different carriers for the delivery of oxaliplatin increased the efficiency and reduced the side effects of the drug. It has been observed that the majority of research investigations have focused on liposomes and polysaccharides.

CONCLUSION

This potentially auspicious method has the potential to enhance results and enhance the quality of life for cancer patients undergoing chemotherapy. However, additional investigation is required to ascertain the most suitable medium for the transportation of oxaliplatin and to assess its efficacy through clinical trials.

Mechanistic insight into differential interactions of iron oxide nanoparticles with native, glycated albumin and their effect on erythrocytes parameters

Nanoparticles and protein bioconjugates have been studied for multiple biomedical applications. We sought to investigate the interaction and structural modifications of bovine serum albumin (BSA) with iron oxide nanoparticles (IONPs). The IONPs were green synthesized using E. crassipes aqueous leaf extract following characterization using transmission electron microscopy, energy dispersive X-ray analysis and X-Ray Diffraction. Two different concentrations of native/glycated albumin (0.5 and 1.5 mg/ml) with IONPs were allowed to interact for 1 h at 37 °C. Glycation markers, protein modification markers, cellular antioxidant, and hemolysis studies showed structural modifications and conformational changes in albumin due to the presence of IONPs. UV-Visible absorbance resulted in hyperchromic and bathochromic effects of IONPs-BSA conjugates. Fluorescence measurements of tyrosine, tryptophan, advanced glycated end products, and ANS binding assay were promising and quenching effects proved IONPs-BSA conjugate formation. In FTIR of BSA-IONPs, transmittance was increased in amide A and B bands while decreased in amide I and II bands. In summary, native PAGE, HPLC, and FTIR analysis displayed a differential behaviour of IONPs with native and glycated BSA. These results provided an understanding of the interaction and structural modifications of glycated and native BSA which may provide fundamental repercussions in future studies.

CD44/Folate Dual Targeting Receptor Reductive Response PLGA-Based Micelles for Cancer Therapy

In this study, a novel poly (lactic-co-glycolic acid) (PLGA)-based micelle was synthesized, which could improve the therapeutic effect of the antitumor drug doxorubicin hydrochloride (DOX) and reduce its toxic and side effects. The efficient delivery of DOX was achieved by active targeting mediated by double receptors and stimulating the reduction potential in tumor cells. FA-HA-SS-PLGA polymer was synthesized by amidation reaction, and then DOX-loaded micelles were prepared by dialysis method. The corresponding surface method was used to optimize the experimental design. DOX/FA-HA-SS-PLGA micelles with high drug loading rate and encapsulation efficiency were prepared. The results of hydrophilic experiment, critical micelle concentration determination, and hemolysis test all showed that DOX/FA-HA-SS-PLGA micelles had good physicochemical properties and biocompatibility. In addition, both in vitro reduction stimulus response experiment and in vitro release experiment showed that DOX/FA-HA-SS-PLGA micelles had reduction sensitivity. Molecular docking experiments showed that it can bind to the target protein. More importantly, in vitro cytology studies, human breast cancer cells (MCF-7), human non-small cell lung cancer cells (A549), and mouse colon cancer cells (CT26) were used to demonstrate that the dual receptor-mediated endocytosis pathway resulted in stronger cytotoxicity to tumor cells and more significant apoptosis. In and in vivo antitumor experiment, tumor-bearing nude mice were used to further confirm that the micelles with double targeting ligands had better antitumor effect and lower toxicity. These experimental results showed that DOX/FA-HA-SS-PLGA micelles have the potential to be used as chemotherapeutic drugs for precise tumor treatment.

Advances in Magnetic Nanoparticles Engineering for Biomedical Applications-A Review

Magnetic iron oxide nanoparticles (MNPs) have been developed and applied for a broad range of biomedical applications, such as diagnostic imaging, magnetic fluid hyperthermia, targeted drug delivery, gene therapy and tissue repair. As one key element, reproducible synthesis routes of MNPs are capable of controlling and adjusting structure, size, shape and magnetic properties are mandatory. In this review, we discuss advanced methods for engineering and utilizing MNPs, such as continuous synthesis approaches using microtechnologies and the biosynthesis of magnetosomes, biotechnological synthesized iron oxide nanoparticles from bacteria. We compare the technologies and resulting MNPs with conventional synthetic routes. Prominent biomedical applications of the MNPs such as diagnostic imaging, magnetic fluid hyperthermia, targeted drug delivery and magnetic actuation in micro/nanorobots will be presented.

PEG size effect and its interaction with Fe3O4 nanoparticles synthesized by solvothermal method: morphology and effect of pH on the stability

The synthesis and characterization of Fe3O4 magnetic nanoparticles (MNPs) obtained by the solvothermal method in ethyleneglycol with the addition of polyethyleneglycol (PEG) with molar mass of 4000, 8000 and 20000 g mol−1 are described, aimed at evaluating its effect on the size, morphology and stability of the nanoparticle. The syntheses were carried out by solubilizing the precursors at 85 and 140 °C, providing smaller nanoparticles as well as smaller crystallites at higher temperatures, while the effect of PEG was less evident. Measurements of nanoparticle surface areas synthesized with PEG 4000 and 20000 g mol−1 at 140 °C provided values of 76 and 14 m2 g−1, respectively, indicating that PEG 4000 surrounds the crystallites, while PEG 20000 preferably surrounds the whole MNP. As a consequence, MNP with very dissimilar porosities were obtained. Electron energy loss spectroscopy (EELS) indicated that MNP synthesized with PEG 20000 possesses higher electronic density than those obtained with PEG 4000, in agreement with the surface area results. Infrared spectroscopy and thermogravimetric analysis demonstrated the presence of PEG in the particles, whose amount increased as the particle size decreased. Dynamic Light Scattering (DLS) measurements showed that MNP hydrodynamic radius increases with the PEG size and stability in solution increases from pH 5.0 to 9.0 for smaller NP, while polymer presents slight effect on stability for the larger particles. The results obtained in this work show that properties of MNP can be tuned by the dissolution temperature of the chemical precursors and the PEG molar mass, changing their porosity and stability in solution, that are important variables in processes of adsorption, drug delivery and sensor developing.

Facile bioinspired synthesis of iron oxide encapsulating silica nanocapsules

Iron oxide nanoparticles have been extensively studied for a wide variety of applications. However, there remains a challenge in developing hierarchical magnetic iron oxide nanoparticles as existing synthetic techniques require harsh, toxic chemical conditions and high temperatures or give poorly defined product with weak magnetic properties. In addition, drug loading is limited to post-loading methods such as chemical conjugation or surface adsorption that have poor loading efficiency and are prone to premature drug release. We report a facile biomimetic method for making iron oxide nanoparticle-loaded silica nanocapsules based on a bimodal catalytic peptide surfactant stabilized nanoemulsion template. Iron oxide nanoparticles can be preloaded into the oil phase of the nanoemulsion at tunable concentrations, and the excellent surface activity of the designed bimodal peptide in combination with sufficient electrostatic repulsion promotes the stability of the nanoemulsions. Biosilicification induced by the catalytic peptide module leads to the formation of silica shell nanocapsules containing a magnetic oil core. The bioinspired silica nanocapsules encapsulating iron oxide nanoparticles demonstrate the next-generation of magnetic nanostructures for drug delivery applications.

Magnetic reduced graphene oxide as a nano-vehicle for loading and delivery of curcumin

Magnetic nanoparticles have been widely used in the field of nanomedicine as drug delivery vehicles for targeted imaging-guided and controlled drug uptake and release actions. In this work, the loading of curcumin on Fe₃O₄/rGO nanocomposites and their interaction mechanism were investigated by multispectral methods including resonance light scattering (RLS), atomic force microscopy (AFM), circular dichroism (CD) and Fourier transform infrared (FT-IR). Results revealed that the drug loading was a complex process which is not governed by a simple adsorption. The interactions of vitro human serum albumin (HSA) with free curcumin and/or curcumin-Fe₃O₄/rGO complex have been studied. Outcomes from the fluorescence quenching showed that the binding constant of curcumin to HSA increased significantly in the presence of Fe₃O₄/rGO, confirming the enhanced effect of Fe₃O₄/rGO besides its low toxicity towards HSA. Findings from this work verified that Fe₃O₄/rGO nanocomposite has a promising potential as a good drug loading carrier that can be used and broad range of therapies.

Rice starch coated iron oxide nanoparticles: A theranostic probe for photoacoustic imaging-guided photothermal cancer therapy

In recent years, suitable bioactive materials coated nanoparticles have attracted substantial attention in the field of biomedical applications. The present study emphasizes experimental details for the synthesis of boiling rice starch extract (BRE) coated iron oxide nanoparticles (IONPs) to treat cancer by photoacoustic imaging (PAI)-guided chemo-photothermal therapy. The solvothermal method was used to synthesize IONPs. The physical immobilization method helps to coat BRE-loaded doxorubicin (DOX) molecules on the iron oxide surface. In vitro drug release was estimated in basic (pH 9.0), neutral (pH 7.2), and acidic (pH 4.5) media for varying time periods using ultraviolet-visible spectroscopy. The chemical and physical properties of the synthesized spherical BRE-IONPs were characterized using sophisticated analytical instrumentation. A magnetic saturation experiment was performed with BRE-IONPs for evaluating possible hyperthermia in targeted drug delivery. The biological activity of the synthesized BRE-IONPs was investigated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and acridine orange/propidium iodide fluorescence cell viability study. BRE-IONPs showed excellent photothermal stability, with a high photothermal conversion efficiency (η = 29.73%), biocompatible property, and high near-infrared region absorption for PAI-guided PTT treatment. This study will provide a better understanding of rice starch as a suitable bioactive coating material for possible theranostic applications.

Relationship between Sphk1/S1P and microRNAs in human cancers

Sphingosine kinases type 1 (SphK1) is a key enzyme in the phosphorylation of sphingosine to sphingosine 1-phosphate (S1P). Different abnormalities in SphK1 functions may correspond with poor prognosis in various cancers. Additionally, upregulated SphK1/S1P could promote cancer cell proliferation, angiogenesis, mobility, invasion, and metastasis. MicroRNAs as conserved small noncoding RNAs play major roles in cancer initiation, progression, metastasis, etc. Their posttranscriptionally mechanisms could affect the development of cancer growth or tumorigenesis suppression. The growing number of studies has described that various microRNAs can be regulated by SphK1, and its expression level can also be regulated by microRNAs. In this review, the relationship of SphK1 and microRNA functions and their interaction in human malignancies have been discussed. Based on them novel treatment strategies can be introduced.

Human Serum Albumin Binds Native Insulin and Aggregable Insulin Fragments and Inhibits Their Aggregation

The purpose of this study was to investigate whether Human Serum Albumin (HSA) can bind native human insulin and its A13–A19 and B12–B17 fragments, which are responsible for the aggregation of the whole hormone. To label the hormone and both hot spots, so that their binding positions within the HSA could be identified, 4-(1-pyrenyl)butyric acid was used as a fluorophore. Triazine coupling reagent was used to attach the 4-(1-pyrenyl)butyric acid to the N-terminus of the peptides. When attached to the peptides, the fluorophore showed extended fluorescence lifetimes in the excited state in the presence of HSA, compared to the samples in buffer solution. We also analyzed the interactions of unlabeled native insulin and its hot spots with HSA, using circular dichroism (CD), the microscale thermophoresis technique (MST), and three independent methods recommended for aggregating peptides. The CD spectra indicated increased amounts of the α-helical secondary structure in all analyzed samples after incubation. Moreover, for each of the two unlabeled hot spots, it was possible to determine the dissociation constant in the presence of HSA, as 14.4 µM (A13–A19) and 246 nM (B12–B17). Congo Red, Thioflavin T, and microscopy assays revealed significant differences between typical amyloids formed by the native hormone or its hot-spots and the secondary structures formed by the complexes of HSA with insulin and A13–A19 and B12–B17 fragments. All results show that the tested peptide-probe conjugates and their unlabeled analogues interact with HSA, which inhibits their aggregation.

T807-modified human serum albumin biomimetic nanoparticles for targeted drug delivery across the blood-brain barrier

Novel biocompatible Human Serum Albumin (HSA) nanoparticles composed of membrane of erythrocytes (ETm)-coated and DSPE-PEG₃₄₀₀-T807 segments have been designed for sustained drug delivery across the blood-brain barrier (BBB). The nanoparticles have developed by induced albumin self-assembly with glutathione as reducing agent. The chemical, physical and biocompatible properties of the T807/ETm-HSA nanoparticles have been characterised by hydrogen nuclear magnetic resonance, matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry, transmission electron microscopy, dynamic light scattering and confocal laser scanning microscopy techniques. The unique targeting properties of the nanoparticles after fabrication with the brain-targeted ligand T807 was demonstrated by their attaching to brain cells as well as their enhanced transport ability to cross the BBB. In a further demonstration of their ability to target brain cells, in vivo living imaging revealed that T807/ETm-HSA nanoparticles accumulated in the mice brain after intravenous injection. The surface modification of ETm/HSA nanoparticles with the brain-targeted T807 demonstrated in this work represents a highly novel and effective strategy to provide efficient brain targeting and shows promise for the future in using modified ETm-coated HSA nanoparticles to penetrate the brain.

In vitro spectroscopic investigation of groove binding interaction of Fe3O4@CaAl-LDH@L-Dopa with calf thymus DNA

The principal goal of this study is to evaluate the interaction of Fe₃O₄@CaAl-LDH@L-Dopa and Fe₃O₄@CaAl-LDH nanoparticles with calf thymus DNA. The magnetic nanoparticles were previously prepared by a chemical co-precipitation method, and the surface of the Fe₃O₄ nanoparticles was coated with CaAl layered double hydroxides. The antiparkinsonian drug "L-Dopa" was carried by this core-shell nanostructure to achieve the drug delivery system with suitable properties for biological applications. Also, the interaction of Fe₃O₄@CaAl-LDH@L-Dopa and Fe₃O₄@CaAl-LDH nanoparticles with CT-DNA was studied using, UV-Visible spectroscopy, viscosity, circular dichroism (CD), and fluorescence spectroscopy techniques. The results of investigations demonstrated that Fe₃O₄@CaAl-LDH@L-Dopa and Fe₃O₄@CaAl-LDH nanoparticles have interacted via minor groove binding and intercalated to CT-DNA, respectively.

Synthesis of magnetic nanoparticles with an IDA or TED modified surface for purification and immobilization of poly-histidine tagged proteins

Magnetic nanoparticles (MNPs) chelating with metal ions can specifically interact with poly-histidine peptides and facilitate immobilization and purification of proteins with poly-histidine tags. Fabrication of MNPs is generally complicated and time consuming. In this paper, we report the preparation of Ni(ii) ion chelated MNPs (Ni-MNPs) in two stages for protein immobilization and purification. In the first stage, organic ligands including pentadentate tris (carboxymethyl) ethylenediamine (TED) and tridentate iminodiacetic acid (IDA) and inorganic Fe₃O₄–SiO₂ MNPs were synthesized separately. In the next stage, ligands were grafted to the surface of MNPs and MNPs with a TED or IDA modified surface were acquired, followed by chelating with Ni(ii) ions. The Ni(ii) ion chelated forms of MNPs (Ni-MNPs) were characterized including morphology, surface charge, structure, size distribution and magnetic response. Taking a his-tagged glycoside hydrolase DspB (Dispersin B) as the protein representative, specific interactions were confirmed between DspB and Ni-MNPs. Purification of his-tagged DspB was achieved with Ni-MNPs that exhibited better performance in terms of purity and activity of DspB than commercial Ni-NTA. Ni-MNPs as enzyme carriers for DspB also exhibited good compatibility and reasonable reusability as well as improved performance in various conditions.

This article reports a novel approach for synthesizing magnetic nanoparticles with a modified surface for purification and immobilization of histidine-tagged proteins.

Impact of immobilization technology in industrial and pharmaceutical applications

The current demands of the world's biotechnological industries are enhancement in enzyme productivity and development of novel techniques for increasing their shelf life. Compared to free enzymes in solution, immobilized enzymes are more robust and more resistant to environmental changes. More importantly, the heterogeneity of the immobilized enzyme systems allows an easy recovery of both enzymes and products, multiple reuse of enzymes, continuous operation of enzymatic processes, rapid termination of reactions, and greater variety of bioreactor designs. This review summarizes immobilization definition, different immobilization methods, advantages and disadvantages of each method. In addition, it covers some food industries, protein purification, human nutrition, biodiesel production, and textile industry. In these industries, the use of enzymes has become an inevitable processing strategy when a perfect end product is desired. It also can be used in many other important industries including health care and pharmaceuticals applications. One of the best uses of enzymes in the modern life is their application in diagnose and treatment of many disease especially when used in drug delivery system or when used in nanoform.

Preparation, characterization and controlled-release property of CS crosslinked MWCNT based on Hericium erinaceus polysaccharides

In present study, the optimal condition of prepared drug was determined by response surface methodology. In addition, their physicochemical properties, drug release and uptake ability of CS-MWCNT-HEP were studied, and the distribution of the drug in ICR mice and the sites of action were further evaluated. Under the optimal condition, the mean experimental loaded efficiency 68.55 ± 1.47% was corresponded well with the predicted value of 68.28%. The results of in vitro experiments proved that a release of the drug in a pH-dependent behavior. Flow cytometry and inverted microscope showed that the uptake of CS-MWCNT-HEP in Raw264.7 cells increased significantly as the time increased. In vivo experiment proved that the HEP and CS-MWCNT-HEP were mainly accumulated in the kidney, shown the characteristics of kidney metabolism. On the other hand, the extended retention of CS-MWCNT-HEP in the mice could enhance the immune function. CS-MWCNT-HEP has high loaded efficiency and pH-responsive drug released, which could significantly improved the body's immunity and enhance the body's ability to absorbed drugs. These findings proposed a well characterized novel CS-MWCNT-HEP formulation as drug delivery system, and its mechanism and application will be further investigated in our undergoing studies.