Coagulation Factor IX-rich protrhombin complex concentrate (FIX-PCC) is a therapeutic biologic product that consists of a mixture of several human plasma-derived proteins, useful for treating hemophilia B. Due to its complex composition, FIX-PCC is very challenging to bioprocess through virus removing nanofilters in order to ensure its biosafety. This article describes a two-step filtration process of FIX-PCC using a nanocellulose-based filter paper with tailored porosity. The filters were characterized with scanning electron microscopy (SEM), cryoporometry with differential scanning calorimetry, and nitrogen gas sorption. Furthermore, in order to probe the filter’s cut-off size rejection threshold, removal of small- and large-size model viruses, i.e., ΦX174 (28 nm) and PR772 (70 nm), was evaluated. The feed, pre-filtrate, and permeate solutions were characterized with mass-spectrometric proteomic analysis, dynamic light scattering (DLS), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and analytical size-exclusion high-performance liquid chromatography (SEHPLC). By sequential filtration through 11 μm pre-filter and 33 μm virus removal filter paper, it was possible to achieve high product throughput and high virus removal capacity. The presented approach could potentially be applied for bioprocessing other protein-based drugs.

Affinity chromatography is a widely used technique for antibody isolation. This article presents the successful synthesis of a novel affinity resin with a mutant form of protein A (BsrtA) immobilized on it as a ligand. The key aspect of the described process is the biocatalytic immobilization of the ligand onto the matrix using the sortase A enzyme. Moreover, we used a matrix with primary amino groups without modification, which greatly simplifies the synthesis process. The resulting resin shows a high dynamic binding capacity (up to 50 mg IgG per 1 mL of sorbent). It also demonstrates high tolerance to 0.1 M NaOH treatment and maintains its effectiveness even after 100 binding, elution, and sanitization cycles.

Background: The authors describe the developmental process of intravenous anti-COVID-19 hyperimmune immunoglobulin from anti-SARS-CoV-2 neutralizing antibody-containing plasma. Furthermore, the aut... Plain language summary An intravenous immunoglobulin with a high concentration of SARS-CoV-2-neutralizing antibodies was prepared from COVID-19 convalescent plasma, which could be utilized as a pas... Tweetable abstract Pure and safe intravenous immunoglobulin with a high concentration of SARS-CoV-2 neutralizing antibodies was produced from #COVID19 convalescent plasma and demonstrated protectiv...

Introduction. Using of immunoglobulins containing SARS-CoV-2 neutralizing antibodies may be an effective and safe tool for COVID-19 treatment. An intravenous immunoglobulin COVID-globulin from donor blood plasma containing SARS-CoV-2 neutralizing antibodies was developed at Joint-Stock Company Nacimbio.Aim. A pilot study of the safety of the "COVID-globulin".Materials and methods. When studying the safety of the preparation in animals the following parameters were evaluated: general toxicity, thrombogenic potential, influence on hematological and biochemical parameters, blood clotting and hemolytic activity, determination of local irritant action, pyrogenic properties, bacterial endotoxins, allergic effect of the drug preparation and its physicochemical characteristics.Results and discussion. Safety studies of "COVID-globulin" in animals showed no signs of intoxication, local irritant action and thrombogenic properties. Macroscopic and histological examination of the organs of rats treated with COVID-globulin showed no signs of necrosis, inflammation, atypia, or any significant pathological changes. Hematological and biochemical parameters of the blood of laboratory animals after the administration of "COVID-globulin" corresponded to the reference values. Administration of COVID-globulin to rabbits did not activate blood clot formation. The IgG subclasses distribution in the preparation corresponded to that in human plasma. The activity of the Fc-function of the immunoglobulin molecule was more than 130 % compared to the reference standard preparation, the concentration of the prekallikrein activator in the COVID-globulin ranged from 4.2 to 4.8 IU/ml, anticomplementary activity was less than 1 unit complement per 1 mg of protein.Conclusion. The results of all studies have demonstrated a high level of safety of the developed COVID-globulin preparation, which meets the safety requirements for human immunoglobulins for intravenous administration by national regulatory documents and the European Pharmacopoeia.

Scientific relevance. Medicinal products based on immunoglobulin class G (IgG) from human plasma are widely used in clinical practice to treat bacterial and viral infections, primary and secondary immunodeficiencies, and autoimmune diseases. Nanofiltration is a way to mitigate the risk of in-process contamination of raw materials with various pathogens, including viruses. Therefore, it is relevant to investigate the development and implementation of additional viral inactivation and/or elimination steps.Aim. This study aimed to develop and validate optimum nanofiltration conditions and to scale up the nanofiltration step for the manufacturing of human IgG for intravenous administration.Materials and methods. The study used a solution of IgG from plasma fractions II and III. The authors paired nanofilters manufactured by Planova 20N and BioEx (Asahi Kasei, Japan), Viresolve Pro (Merck Millipore, USA), Virosart HC and HF (Sartorius, Germany), and Pegasus SV4 and Prime (Pall, USA) with Sartopore polyethersulphone prefilters by Sartorius (Germany), Virosart MAX polyamide prefilters by Sartorius (Germany), and EKX-P regenerated cellulose prefilters by Pall (Germany). Virus reduction validation studies were performed with model viruses (human immunodeficiency virus type 1, porcine transmissible gastroenteritis virus, porcine parvovirus, murine encephalomyocarditis virus, and bovine viral diarrhoea virus) in the laboratories of the N.F. Gamaleya centre. The sample data analysis involved calculating mean values with 95% confidence intervals.Results. For all the selected combinations of prefilters and filters, the maximum nanofiltration throughput depended on the IgG concentration in the test solution. With the combination of an EKX-P filter with a Pegasus SV4 nanofilter, the maximum throughput and the IgG yield reached 6300 g/m² and 95%, respectively. When combined with a Planova 20N nanofilter, EKX-P and Sartopore (polyethersulphone) filters provided a maximum throughput of up to 2980 g/m² and an IgG yield of almost 100%, provided that the test solution had an IgG concentration of 10 g/L. With different filter combinations, virus reduction levels ranged from 4.00±0.05 to 4.75±0.04 log₁₀ for human immunodeficiency virus type 1, from 4.30±0.04 to 4.55±0.06 log₁₀ for porcine transmissible gastroenteritis virus, from 5.38±0.08 log10 to 5.57±0.04 log₁₀ for murine encephalomyocarditis virus, 5.12±0.10 log₁₀ to 5.25±0.08 log₁₀ for porcine parvovirus, and exceeded 5.00 log₁₀ for bovine viral diarrhoea virus. The virus reduction levels achieved were not statistically associated with prefilter brands.Conclusions. The study demonstrated that nanofiltration was effective at removing viruses with various virion sizes and physicochemical characteristics, including viruses as small as parvovirus B19. The levels of virus reduction exceeded 4 log₁₀ and met the acceptance criteria.The laboratory-scale nanofiltration parameters and the corresponding filtration times, as well as IgG yields, did not change when the process was scaled up. Therefore, nanofiltration is an effective and productive technique that helps eliminate various types of viruses and considerably improve viral safety without affecting the quality of biological medicinal products.