Publications by authors named "Nejadnik M"

The foundation of a biosimilar manufacturer's regulatory filing is the demonstration of analytical and functional similarity between the biosimilar product and the pertinent originator product. The excipients in the formulation may interfere with characterization using typical analytical and functional techniques during this biosimilarity exercise. Consequently, the producers of biosimilar products resort to buffer exchange to isolate the biotherapeutic protein from the drug product formulation.

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Monoclonal antibodies (mAbs) can be damaged during the aseptic compounding process, with aggregation being the most prevalent form of degradation. Protein aggregates represent one of several risk factors for undesired immunogenicity of mAbs, which can potentially lead to severe adverse drug reactions and less effective treatments. Since data on aggregate and particle formation by robotic compounding is missing, we aimed to compare the antibody stability between robotic- and manual compounding of mAbs with regard to formation of (sub)visible aggregates.

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A survey performed by the AAPS Drug Product Handling community revealed a general, mostly consensus, approach to the strategy for the selection of surfactant type and level for biopharmaceutical products. Discussing and building on the survey results, this article describes the common approach for surfactant selection and control strategy for protein-based therapeutics and focuses on key studies, common issues, mitigations, and rationale. Where relevant, each section is prefaced by survey responses from the 22 anonymized respondents.

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The purpose of this study was to optimize the manufacturing of dissolving microneedles (dMNs) and to increase the antigen loading in dMNs to investigate the effect on their physicochemical properties. To achieve this, a novel single-array wells polydimethylsiloxane mold was designed, minimizing antigen wastage during fabrication and achieving homogeneous antigen distribution among the dMN arrays. Using this mold, hyaluronan (HA)-based dMNs were fabricated and tested for maximal ovalbumin (OVA) content.

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Microneedle technologies have been developed for dermal drug and vaccine delivery, including hollow-, solid-, coated-, and dissolving microneedles. Microneedles have been made in many different geometries and of many different materials, all of which may influence their skin-penetrating ability. To ensure reproducible and effective drug and vaccine delivery via microneedles, the optimal insertion parameters should be known.

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Purpose: To investigate the potential of two flow imaging microscopy (FIM) techniques (Micro-Flow Imaging (MFI) and FlowCAM) to determine total cell concentration and cell viability.

Methods: B-lineage acute lymphoblastic leukemia (B-ALL) cells of 2 different donors were exposed to ambient conditions. Samples were taken at different days and measured with MFI, FlowCAM, hemocytometry and automated cell counting.

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Skin is an attractive but also very challenging immunisation site for particulate subunit vaccines. The aim of this study was to develop hyaluronan (HA)-based dissolving microneedles (MNs) loaded with PLGA nanoparticles (NPs) co-encapsulating ovalbumin (OVA) and poly(I:C) for intradermal immunisation. The NP:HA ratio used for the preparation of dissolving MNs appeared to be critical for the quality of MNs and their dissolution in ex vivo human skin.

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The safety and efficacy of protein pharmaceuticals depend not only on biological activity but also on purity levels. Impurities may be process related because of limitations in manufacturing or product related because of protein degradation occurring throughout the life history of a product. Although the pharmaceutical biotechnology industry has made great progress in improving bulk and drug product manufacturing as well as company-controlled storage and transportation conditions to minimize the level of degradation, there is less control over the many factors that may subsequently affect product quality after the protein pharmaceuticals are released and shipped by the manufacturer.

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Purpose: To measure aggregate and particle formation in tumor necrosis factor-alpha (TNF-α) inhibitors etanercept, adalimumab and certolizumab pegol product samples after exposure to freezing temperature conditions similar to storage conditions previously observed in patients' homes.

Methods: TNF-α inhibitors in their original primary and secondary packaging were exposed to 32 freeze-thaw cycles (-10°C for 120min/5°C for 60 min) or continuous low storage temperature (-20°C for 96 h) before thawing at 2-8°C. Non-stressed products were used as controls.

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Objectives: Anti-citrullinated protein antibodies (ACPA) are highly specific for rheumatoid arthritis (RA). Here, we studied binding of ACPA-IgG immune complexes (IC) to individual Fc gamma receptors (FcγR) to identify potential effector mechanisms by which ACPA could contribute to RA pathogenesis.

Methods: ACPA-IgG1 and control IgG1(IgG1 depleted of ACPA-IgG1) were isolated from plasma and synovial fluid (SF) of RA patients by affinity chromatography using CCP2 peptides.

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In this study, we investigated the potential of intradermal delivery of nanoparticulate vaccines to modulate the immune response of protein antigen using hollow microneedles. Four types of nanoparticles covering a broad range of physiochemical parameters, namely poly (lactic-co-glycolic) (PLGA) nanoparticles, liposomes, mesoporous silica nanoparticles (MSNs) and gelatin nanoparticles (GNPs) were compared. The developed nanoparticles were loaded with a model antigen (ovalbumin (OVA)) with and without an adjuvant (poly(I:C)), followed by the characterization of size, zeta potential, morphology, and loading and release of antigen and adjuvant.

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The release of drugs from poly(lactic-co-glycolic acid) (PLGA) microparticles depends to a large extent on the porosity of the particles. Therefore, porosity determination of PLGA microparticles is extremely important during pharmaceutical product development. Currently, mercury intrusion porosimetry (MIP) is widely used despite its disadvantages, such as the need for a large amount of sample (several hundreds of milligrams) and residual toxic waste.

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A master student, who surveyed the procedures in a hospital pharmacy with regard to the handling of biologicals, identified several issues that might have jeopardized product quality. This case may be a tip of the iceberg and illustrates the urgent need for a better education of end-users about how to handle biologicals.

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Purpose: To investigate whether particle sedimentation velocity tracking using a flow imaging microscope (FlowCAM) can be used to determine microparticle porosity.

Methods: Two different methods were explored. In the first method the sedimentation rate of microparticles was tracked in suspending media with different densities.

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Nanoparticle tracking analysis (NTA) has attracted great interest for application in the field of submicron particle characterization for biopharmaceuticals. It has the virtue of direct sample visualization and particle-by-particle tracking, but the complexity of method development has limited its routine applicability. We systematically evaluated data collection and processing parameters as well as sample handling methods using shake-stressed protein samples.

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This study addressed the effect of contact sliding during stirring of a monoclonal antibody solution on protein aggregation, in particular, in the nanometer and micrometer size range. An overhead stirring set-up was designed in which the presence and magnitude of the contact between the stir bar and the container could be manipulated. A solution of 0.

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Human serum albumin (HSA)-free formulation of Escherichia coli-derived human interferon beta (IFNβ-1b) with a high percentage of monomeric protein and low immunogenicity is developed and characterized in the current study. UV spectroscopy, fluorescence spectroscopy, dynamic light scattering, sodium dodecyl sulfate polyacrylamide gel electrophoresis, Western blotting, Micro-Flow Imaging, resonant mass measurement, size exclusion, and reversed-phase high performance liquid chromatographies were applied to assess the effect of excipients on the stability of IFNβ-1b to establish a HSA-free formulation. The antiviral activity of IFNβ-1b was evaluated using human lung carcinoma cell line.

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The purpose of this study was to investigate the formation and growth kinetics of complexes of proteins and oppositely charged polyelectrolytes. Equal volumes of IgG and dextran sulfate (DS) solutions, 0.01 mg/ml each in 10mM phosphate, pH 6.

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We assessed the potential of a suspended microchannel resonator (SMR) to measure the adsorption of proteins to nanoparticles. Standard polystyrene beads suspended in buffer were weighed by a SMR system. Particle suspensions were mixed with solutions of bovine serum albumin (BSA) or monoclonal human antibody (IgG), incubated at room temperature for 3 h and weighed again with SMR.

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The search for alternative therapies to improve bone regeneration continues to be a major challenge for the medical community. Here we report on the enhanced mineralization, osteogenesis, and in vivo bone regeneration properties of a bioactive elastin-like recombinamer (ELR) membrane. Three bioactive ELRs exhibiting epitopes designed to promote mesenchymal stem cell adhesion (RGDS), mineralization (DDDEEKFLRRIGRFG), and both cell adhesion and mineralization were synthesized using standard recombinant protein techniques.

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Non-covalent interactions are often regarded as insufficient to construct macroscopic materials of substantial integrity and cohesion. However, the low binding energy of such reversible interactions can be compensated by increasing their number to work in concert to create strong materials. Here we present the successful development of an injectable, cohesive nanocomposite hydrogel based on reversible bonds between calcium phosphate nanoparticles and bisphosphonate-functionalized hyaluronic acid.

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The current study focused on the development of a rapid, straightforward quantification method based on the use of enzymatic decomposition of urea using urease to assess the mineralization capacity of a wide range of biomaterials for bone regeneration. Urea-containing mineralizing solutions (MSs) (containing: Na2HPO4, CaCl2, and NaCl at 37°C and pH 6.0) were used in the mineralization experiments.

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The current study examines the enzymatic decomposition of urea into carbon dioxide and ammonia as a means to increase the pH during biomimetic deposition of calcium phosphate (CaP) onto implant surfaces. The kinetics of the enzymatically induced pH increase were studied by monitoring pH, calcium concentration and conductivity of the aqueous solutions as a function of time, urease concentration and initial concentrations of calcium and phosphate ions. Cryogenic transmission electron microscopy was used to study the process of homogeneous CaP precipitation in solution, whereas CaP deposition on conventional acid-etched titanium and micropatterned polystyrene (PS) surfaces was studied using scanning electron microscopy.

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