Preparation of anti-CD4 monoclonal antibody-conjugated magnetic poly(glycidyl methacrylate) particles and their application on CD4+ lymphocyte separation

An overview on the investigation of nanomaterials' effect on plasma components: immunoglobulins and coagulation factor VIII, 2010-2020 review

FVIII and immunoglobulins (Igs) are the most prominent plasma proteins, which play a vital role in plasma hemostasis. These proteins have been implemented frequently in protein therapy. Therefore, their maintenance, durability, and stability are highly essential. Herein, various approaches to improve protein functions have been investigated, such as using recombinant protein replacement. In comparison, advances in nanotechnology have provided adequate context to boost biomaterial utilization. In this regard, the applications of various nanoparticles such as polymeric nanomaterials (PEG and PLGA), metal nanoparticles, dendrimers, and lipid based nanomaterials (liposomes and lipid nanoparticles) in stability and the functional improvement of antibodies and coagulation factor VIII (FVIII) have been reviewed from 2010 to 2020. Reviewing related articles has shown that not only can nanomaterials adequately protect the structure of proteins, but have also improved proteins' functions in some cases. For example, the high rate of FVIII instability has been successfully enhanced by bio-PEGylation. Also, utilizing PEGylated liposomes, using the PEG-lip technique for coating nanostructures, leads to FIIIV half-life prolongation. Hence, PEGylation had most impact on the stability of FVIII. Likewise, PEG-coated liposome nano-carriers also presented such a good effect on stability improvements for FVIII due to their ability to tune the immune system by reducing FVIII immunogenicity. Similarly, Ig PEGylation and conjugation to magnetic nanoparticles resulted in increased half-life and better purification of Igs, respectively, without any loss in structural or functional features. Consequently, metal-organic frameworks and recent hybrid systems have been introduced as promising nanomaterials in biomedical applications. As far as we know, this is the first study in this field, which considers the applications of nanoparticles for improving the storage and stability of antibodies and coagulation FVIII.

Past, Present, and Future of Affinity-based Cell Separation Technologies

Progress in cell purification technology is critical to increase the availability of viable cells for therapeutic, diagnostic, and research applications. A variety of techniques are now available for cell separation, ranging from non-affinity methods such as density gradient centrifugation, dielectrophoresis, and filtration, to affinity methods such as chromatography, two-phase partitioning, and magnetic-/fluorescence-assisted cell sorting. For clinical and analytical procedures that require highly purified cells, the choice of cell purification method is crucial, since every method offers a different balance between yield, purity, and bioactivity of the cell product. For most applications, the requisite purity is only achievable through affinity methods, owing to the high target specificity that they grant. In this review, we discuss past and current methods for developing cell-targeting affinity ligands and their application in cell purification, along with the benefits and challenges associated with different purification formats. We further present new technologies, like stimuli-responsive ligands and parallelized microfluidic devices, towards improving the viability and throughput of cell products for tissue engineering and regenerative medicine. Our comparative analysis provides guidance in the multifarious landscape of cell separation techniques and highlights new technologies that are poised to play a key role in the future of cell purification in clinical settings and the biotech industry. STATEMENT OF SIGNIFICANCE: Technologies for cell purification have served science, medicine, and industrial biotechnology and biomanufacturing for decades. This review presents a comprehensive survey of this field by highlighting the scope and relevance of all known methods for cell isolation, old and new alike. The first section covers the main classes of target cells and compares traditional non-affinity and affinity-based purification techniques, focusing on established ligands and chromatographic formats. The second section presents an excursus of affinity-based pseudo-chromatographic and non-chromatographic technologies, especially focusing on magnetic-activated cell sorting (MACS) and fluorescence-activated cell sorting (FACS). Finally, the third section presents an overview of new technologies and emerging trends, highlighting how the progress in chemical, material, and microfluidic sciences has opened new exciting avenues towards high-throughput and high-purity cell isolation processes. This review is designed to guide scientists and engineers in their choice of suitable cell purification techniques for research or bioprocessing needs.

Optimization and comparison of CD4-targeting lipid-polymer hybrid nanoparticles using different binding ligands

Monoclonal antibodies and peptides are conjugated to the surface of nanocarriers (NCs) for targeting purposes in numerous applications. However, targeting efficacy may vary with their specificity, affinity, or avidity when linked to NCs. The physicochemical properties of NCs may also affect targeting. We compared the targeting efficacy of the CD4 binding peptide BP4 and an anti-CD4 monoclonal antibody (CD4 mAb) and its fragments, when conjugated to lipid-coated poly(lactic-co-glycolic) acid nanoparticles (LCNPs). Negatively charged LCNPs with cholesteryl butyrate in the lipid layer (cbLCNPs) dramatically reduced nonspecific binding, leading to higher targeting specificity, compared to neutral or positively charged LCNPs with DOTAP (dtLCNP). cbLCNPs surface conjugated with a CD4 antibody (CD4-cbLCNPs) or its fragments (fCD4-cbLCNPs), but not BP4, showed high binding in vitro to the human T cell line 174xCEM, and preferential binding to CD3+ CD14-CD8- cells from pigtail macaque peripheral blood mononuclear cells. CD4-cbLCNPs showed 10-fold higher binding specificity for CD4+ than CD8+ T cells, while fCD4-cbLCNPs demonstrated the highest binding level overall, but only three-fold higher binding specificity. This study demonstrates the importance of ζ-potential on NC targeting and indicates that CD4 mAb and its fragments are the best candidates for delivery of therapeutic agents to CD4+ T cells. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1177-1188, 2018.

Enrichment of human Vγ9Vδ2 T lymphocytes by magnetic poly(divinylbenzene-co-glycidyl methacrylate) colloidal particles conjugated with specific antibody

γδ T cells play a significant role in protection against cancer. Purification of γδ T cells is needed for insight when studying their anti-cancer functionality and their utilization in adoptive cell therapy. To improve the purification of γδ T cells, in this work, a composite material based on magnetic nanoparticles was developed for purification of Vγ9Vδ2 T cells, the predominant subset of γδ T lymphocytes in human peripheral blood. The epoxy-functionalized magnetic poly(divinylbenzene-co-glycidyl methacrylate) particles (mPDGs) were bio-conjugated with anti-human Vδ2 antibody to provide specific recognition sites for T cell receptors of Vγ9Vδ2 T cells. Using fluorescence-activated cell sorting (FACS) analysis, separation of Vγ9Vδ2 T cells from peripheral blood mononuclear cells of healthy donors was confirmed with high purity [89.77% (range 87.00–91.80, n = 3)]. More interestingly, the immobilized particles did not affect the viability of purified cells as high cell viability was indicated (>90%). By combining the properties of magnetic nanoparticles with specific antibodies, these immobilized particles were shown to be used as a cell-friendly purification tool of Vγ9Vδ2 T lymphocytes without any limits for the further use of cells. The purified Vγ9Vδ2 T cells using the antibody-immobilized epoxy-functionalized mPDGs could be used directly without a detachment step for further cultivation and expansion. This highlights the advantages of this method in allowing the study of cell function and further investigation of such rare T cell populations in immunotherapy.

Schematic procedure of Vγ9Vδ2 T cell purification using antibody-immobilized epoxy-functionalized mPDGs.

Supercritical synthesis of poly (2-dimethylaminoethyl methacrylate)/ferrite nanocomposites for real-time monitoring of protein release

A supercritical carbon dioxide (SCC)-assisted process was developed to synthesize protein-supported poly (2-dimethylaminoethyl methacrylate)/ferrite nanocomposites (PNCs). The process involve 2,2-azobisisobutyronitrile-initiated in situ polymerization of 2-dimethylaminoethyl methacrylate in presence of ferrite nanoparticles and bisacrylamide at 90 ± 1 °C, 1200 psi over 6 h in SCC. This was followed by subsequent loading of bovine serum albumin (BSA) as a model protein over PNCs in phosphate buffer (PBS, pH 7.4) at 1200 psi, 35 ± 1 °C over additional 2 h in SCC. The formation of PNCs was ascertained through ultraviolet-visible, Fourier transform-infrared, X-ray diffraction spectra, transmission electron, atomic force microscopy and magnetometry. The developed process extends large scale production of nanomagnetic PNCs suitable as carrier for protein release applications with optimal release properties. The release of protein from PNCs under in vitro in PBS down to nanomolar range with high temporal resolution, speed and reproducibility was quantified through square wave voltammetry.

Targeted delivery of polyamidoamine-paclitaxel conjugate functionalized with anti-human epidermal growth factor receptor 2 trastuzumab

Background

Antibody-dendrimer conjugates have the potential to improve the targeting and release of chemotherapeutic drugs at the tumor site while reducing adverse side effects caused by drug accumulation in healthy tissues. In this study, trastuzumab (TMAB), which binds to human epidermal growth factor receptor 2 (HER2), was used as a targeting agent in a TMAB-polyamidoamine (PAMAM) conjugate carrying paclitaxel (PTX) specifically to cells overexpressing HER2.

Methods

TMAB was covalently linked to a PAMAM dendrimer via bifunctional polyethylene glycol (PEG). PTX was conjugated to PAMAM using succinic anhydride as a cross-linker, yielding TMAB-PEG-PAMAM-PTX. Dynamic light scattering and transmission electron microscopy were used to characterize the conjugates. The cellular uptake and in vivo biodistribution were studied by fluorescence microscopy, flow cytometry, and Carestream In Vivo FX, respectively.

Results

Nuclear magnetic resonance spectroscopy demonstrated that PEG, PTX, fluorescein isothiocyanate, and cyanine7 were conjugated to PAMAM. Ultraviolet-visible spectroscopy and sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated that TMAB was conjugated to PEG-PAMAM. Dynamic light scattering and transmission electron microscopy measurements revealed that the different conjugates ranged in size between 10 and 35 nm and had a spherical shape. In vitro cellular uptake demonstrated that the TMAB-conjugated PAMAM was taken up by HER2-overexpressing BT474 cells more efficiently than MCF-7 cells that expressed lower levels of HER2. Co-localization experiments indicated that TMAB-conjugated PAMAM was located in the cytoplasm. The in vitro cytotoxicity of TMAB-conjugated PAMAM was lower than free PTX due to the slow release of PTX from the conjugate. In vivo targeting further demonstrated that TMAB-conjugated PAMAM accumulated in the BT474 tumor model more efficiently than non-conjugated PAMAM.

Conclusion

TMAB can serve as an effective targeting agent, and the TMAB-conjugated PAMAM can be exploited as a potential targeted chemotherapeutic drug delivery system for tumors that overexpress HER2.

Bench-to-bedside translation of magnetic nanoparticles

Magnetic nanoparticles (MNPs) are a new and promising addition to the spectrum of biomedicines. Their promise revolves around the broad versatility and biocompatibility of the MNPs and their unique physicochemical properties. Guided by applied external magnetic fields, MNPs represent a cutting-edge tool designed to improve diagnosis and therapy of a broad range of inflammatory, infectious, genetic and degenerative diseases. Magnetic hyperthermia, targeted drug and gene delivery, cell tracking, protein bioseparation and tissue engineering are but a few applications being developed for MNPs. MNPs toxicities linked to shape, size and surface chemistry are real and must be addressed before clinical use is realized. This article presents both the promise and perils of this new nanotechnology, with an eye towards opportunity in translational medical science.

Bench-to-bedside translation of magnetic nanoparticles

Magnetic nanoparticles (MNPs) are a new and promising addition to the spectrum of biomedicines. Their promise revolves around the broad versatility and biocompatibility of the MNPs and their unique physicochemical properties. Guided by applied external magnetic fields, MNPs represent a cutting-edge tool designed to improve diagnosis and therapy of a broad range of inflammatory, infectious, genetic and degenerative diseases. Magnetic hyperthermia, targeted drug and gene delivery, cell tracking, protein bioseparation and tissue engineering are but a few applications being developed for MNPs. MNPs toxicities linked to shape, size and surface chemistry are real and must be addressed before clinical use is realized. This article presents both the promise and perils of this new nanotechnology, with an eye towards opportunity in translational medical science.

RGD-conjugated iron oxide magnetic nanoparticles for magnetic resonance imaging contrast enhancement and hyperthermia

The purpose of this study was to develop a specific targeting magnetic nanoparticle probe for magnetic resonance imaging and therapy in the form of local hyperthermia. Carboxymethyl dextran-coated ultrasmall superparamagnetic iron oxide nanoparticles with carboxyl groups were coupled to cyclic arginine-glycine-aspartic peptides for integrin α(v)β₃ targeting. The particle size, magnetic properties, heating effect, and stability of the arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide were measured. The arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide demonstrates excellent stability and fast magneto-temperature response. Magnetic resonance imaging signal intensity of Bcap37 cells incubated with arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide was significantly decreased compared with that incubated with plain ultrasmall superparamagnetic iron oxide. The preferential uptake of arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide by target cells was further confirmed by Prussian blue staining and confocal laser scanning microscopy.