A multicenter comparison study between the Endosafe PTS rapid-release testing system and traditional methods for detecting endotoxin in cell-therapy products

Successful transport across continents of GMP-manufactured and cryopreserved culture-expanded human fetal liver-derived mesenchymal stem cells for use in a clinical trial

Introduction

Cell therapy has been increasingly considered to treat diseases, but it has been proven difficult to manufacture the same product at multiple manufacturing sites. Thus, for a wider implementation an alternative is to have one manufacturing site with a wide distribution to clinical sites. To ensure administration of a good quality cell therapy product with maintained functional characteristics, several obstacles must be overcome, which includes for example transfer of knowledge, protocols and procedures, site assessment, transportation and preparation of the product.

Methods

As the preparatory work for a clinical trial in India using fetal mesenchymal stem cells (fMSCs) developed and manufactured in Sweden, we performed a site assessment of the receiving clinical site, transferred methods, developed procedures and provided training of operators for handling of the cell therapy product. We further developed a Pharmacy Manual to cover the management of the product, from ordering it from the manufacturer, through transport, reconstitution, testing and administration at the clinical site. Lastly, the effect of long-distance transport on survival and function of, as well as the correct handling of the cell therapy product, was evaluated according to the pre-determined and approved Product Specification.

Results

Four batches of cryopreserved human fetal liver-derived fMSCs manufactured according to Good Manufacturing Practice and tested according to predetermined release criteria in Sweden, were certified and transported in a dry shipper at -150 °C to the clinical site in India. The transport was temperature monitored and took three-seven days to complete. The thawed and reconstituted cells showed more than 80% viability up to 3 h post-thawing, the cell recovery was more than 94%, the cells displayed the same surface protein expression pattern, differentiated into bone, had stable chromosomes and were sterile, which conformed with the data from the manufacturing site in Sweden.

Conclusions

Our study shows the feasibility of transferring necessary knowledge and technology to be able to carry out a clinical trial with a cell therapy product in distant country. It also shows that it is possible to transport a cryopreserved cell therapy product over long distances and borders with retained quality. This extends the use of cryopreserved cell therapy products in the future.

Human Fibroblast Growth Factor-Treated Adipose-Derived Stem Cells Facilitate Wound Healing and Revascularization in Rats with Streptozotocin-Induced Diabetes Mellitus

Diabetes mellitus contributes to 15-25% of all chronic foot ulcers. Peripheral vascular disease is a cause of ischemic ulcers and exacerbates diabetic foot disease. Cell-based therapies are viable options to restore damaged vessels and induce the formation of new vessels. Adipose-derived stem cells (ADSCs) have the potential for angiogenesis and regeneration because of their greater paracrine effect. Preclinical studies are currently using other forced enhancement techniques (e.g., genetic modification or biomaterials) to increase the efficacy of human ADSC (hADSC) autotransplantation. Unlike genetic modifications and biomaterials, many growth factors have been approved by the equivalent regulatory authorities. This study confirmed the effect of enhanced human ADSC (ehADSC)s with a cocktail of FGF and other pharmacological agents to promote wound healing in diabetic foot disease. In vitro, ehADSCs exhibited a long and slender spindle-shaped morphology and showed significantly increased proliferation. In addition, it was shown that ehADSCs have more functionalities in oxidative stress toleration, stem cell stemness, and mobility. In vivo, the local transplantation of 1.2 × 10⁶ hADSCs or ehADSCs was performed in animals with diabetes induced by STZ. The ehADSC group showed a statistically decreased wound size and increased blood flow compared with the hADSC group and the sham group. Human Nucleus Antigen (HNA) positive cells were observed in some ADSC-transplanted animals. The ehADSC group showed a relatively higher portion of HNA-positive animals than the hADSC group. The blood glucose levels showed no significant difference among the groups. In conclusion, the ehADSCs showed a better performance in vitro, compared with conventional hADSCs. Additionally, a topical injection of ehADSCs into diabetic wounds enhanced wound healing and blood flow, while improving histological markers suggesting revascularization.

Radiolabeled nanomaterial for cancer diagnostics and therapeutics: principles and concepts

In the last three decades, radiopharmaceuticals have proven their effectiveness for cancer diagnosis and therapy. In parallel, the advances in nanotechnology have fueled a plethora of applications in biology and medicine. A convergence of these disciplines has emerged more recently with the advent of nanotechnology-aided radiopharmaceuticals. Capitalizing on the unique physical and functional properties of nanoparticles, radiolabeled nanomaterials or nano-radiopharmaceuticals have the potential to enhance imaging and therapy of human diseases. This article provides an overview of various radionuclides used in diagnostic, therapeutic, and theranostic applications, radionuclide production through different techniques, conventional radionuclide delivery systems, and advancements in the delivery systems for nanomaterials. The review also provides insights into fundamental concepts necessary to improve currently available radionuclide agents and formulate new nano-radiopharmaceuticals.

Advanced Technologies for Potency Assay Measurement

Crucial for their application, cell products need to be well-characterized in the cell manufacturing facilities and conform to regulatory approval criteria before infusion into the patients. Mesenchymal Stromal Cells (MSCs) are the leading cell therapy candidate in clinical trials worldwide. Early phase clinical trials have demonstrated that MSCs display an excellent safety profile and are well tolerated. However, MSCs have also exhibited contradictory efficacy in later-phase clinical trials with reasons for this discrepancy including poorly understood mechanism of MSC therapeutic action. With likelihood that a number of attributes are involved in MSC derived clinical benefit, an assay that measures a single quality of may not adequately reflect potency, thus a combination of bioassays and analytical methods, collectively called "assay matrix" are favoured for defining the potency of MSC more adequately. This chapter highlights advanced technologies and targets that can achieve quantitative measurement for a range of MSC attributes, including immunological, genomic, secretome, phosphorylation, morphological, biomaterial, angiogenic and metabolic assays.

Development and clinical translation considerations for the next wave of gene modified hematopoietic stem and progenitor cells therapies

INTRODUCTION

Consistent and reliable manufacture of gene modified hematopoietic stem and progenitor cell (HPSC) therapies will be of the utmost importance as they become more mainstream and address larger populations. Robust development campaigns will be needed to ensure that these products will be delivered to patients with the highest quality standards.

AREAS COVERED

Through publicly available manuscripts, press releases, and news articles - this review touches on aspects related to HSPC therapy, development, and manufacturing.

EXPERT OPINION

Recent advances in genome modification technology coupled with the longstanding clinical success of HSPCs warrants great optimism for the next generation of engineered HSPC-based therapies. Treatments for some diseases that have thus far been intractable now appear within reach. Reproducible manufacturing will be of critical importance in delivering these therapies but will be challenging due to the need for bespoke materials and methods in combination with the lack of off-the-shelf solutions. Continued progress in the field will manifest in the form of industrialization which currently requires attention and resources directed toward the custom reagents, a focus on closed and automated processes, and safer and more precise genome modification technologies that will enable broader, faster, and safer access to these life-changing therapies.

The effect of sodium butyrate supplementation on ruminal and fecal pH and serum lipopolysaccharide-binding protein after ruminal acidosis challenge in nonlactating cows

The objective of this study was to evaluate effects of sodium-butyrate supplementation on gastrointestinal function and the inflammatory response to ruminal acidosis (RA) challenge in cows. Four nonlactating cows with a rumen cannula were assigned to two treatments in a crossover design. Treatments were ruminal administration of sodium-butyrate (BUT) or control (CON). Sodium-butyrate was provided as Gustor BP70 and administered at a butyrate dose of 0.04% per kg body weight. The CON premix was made by replacing sodium-butyrate with wheat bran. Experimental periods were 28 days long with 21-day washout period separating the treatments. On Day 25 of each period, corn starch was ruminally administered at 0.7% per kg body weight as RA challenge. After RA challenge, ruminal pH was lower, and endotoxin concentration was higher for cows provided with BUT than those with CON, but the increase in fecal starch and the decrease in fecal pH were attenuated by BUT. The effect of butyrate supplementation on serum lipopolysaccharide-binding protein after RA challenge was not found. From these findings, butyrate supplementation mitigated rectal acidosis by reducing the flux of fermentable carbohydrate into the large intestine. An anti-inflammatory effect of butyrate was not observed, possibly due to lower pH and higher endotoxin concentration in the rumen.

Complete intra-laboratory validation of a LAL assay for bacterial endotoxin determination in EBV-specific cytotoxic T lymphocytes

Endotoxin content is a critical factor that affects the safety of biological pharmaceutical products. International pharmacopoeias describe several reference methods to determine endotoxin levels in advanced therapy medicinal product (ATMP) preparations. Administration of ATMPs must be done as rapidly as possible to ensure complete viability and potency of the cellular product. To evaluate the endotoxin content in the shortest time possible, we chose to validate an alternative method based on the use of the Charles River Portable Testing System (PTS) and FDA-approved cartridges, compliant with the requirements of the European Pharmacopoeia and providing results in <20 min. Here, we describe a unique and complete validation approach for instrument, personnel, and analytical method for assessment of endotoxins in ATMP matrices. The PTS system provides high sensitivity and fast quantitative results and uses less raw material and accessories compared with compendial methods. It is also less time consuming and less prone to operator variability. Our validation approach is suitable for a validated laboratory with trained personnel capable of conducting the ATMP release tests, and with very low intra-laboratory variability, and meets the criteria required for an alternative approach to endotoxin detection for in-process and product-release testing of ATMPs.

The National Heart, Lung, and Blood Institute-funded Production Assistance for Cellular Therapies (PACT) program: Eighteen years of cell therapy

The Production Assistance for Cellular Therapies (PACT) Program, is funded and supported by the US Department of Health and Human Services’ National Institutes of Health (NIH) National Heart Lung and Blood Institute (NHLBI) to advance development of somatic cell and genetically modified cell therapeutics in the areas of heart, lung, and blood diseases. The program began in 2003, continued under two competitive renewals, and ended June 2021. PACT has supported cell therapy product manufacturing, investigational new drug enabling preclinical studies, and translational services, and has provided regulatory assistance for candidate cell therapy products that may aid in the repair and regeneration of damaged/diseased cells, tissues, and organs. PACT currently supports the development of novel cell therapies through five cell processing facilities. These facilities offer manufacturing processes, analytical development, technology transfer, process scale‐up, and preclinical development expertise necessary to produce cell therapy products that are compliant with Good Laboratory Practices, current Good Manufacturing Practices, and current Good Tissue Practices regulations. The Emmes Company, LLC, serves as the Coordinating Center and assists with the management and coordination of PACT and its application submission and review process. This paper discusses the impact and accomplishments of the PACT program on the cell therapy field and its evolution over the duration of the program. It highlights the work that has been accomplished and provides a foundation to build future programs with similar goals to advance cellular therapeutics in a coordinated and centralized programmatic manner to support unmet medical needs within NHLBI purview.

Miniaturization, Parallelization, and Automation of Endotoxin Detection by Centrifugal Microfluidics

We demonstrate microfluidic automation and parallelization of Limulus amebocyte lysate (LAL)-based bacterial endotoxin testing using centrifugal microfluidics. LAL is the standard reagent to test for endotoxin contaminations in injectable pharmaceuticals. The main features of the introduced system are more than 90% reduction of LAL consumption, from 100 μL/reaction to 9.6 μL/reaction, automated liquid handling to reduce opportunities for contamination and manual handling errors, and microfluidic parallelization by integrating 104 reactions into a single centrifugal microplate. In a single Eclipse microplate, 21 samples and their positive product controls are tested in duplicate. In addition, a standard curve with up to five points is generated, resulting in a total of 104 reactions. Test samples with a defined concentration of 0.5 endotoxin units per milliliter were tested, resulting in a coefficient of variation below 0.75%. A key feature for achieving a small coefficient of variation is ensuring the same path length along the microfluidic channels to the final reaction chambers for each sample and the reagent, so that any unspecific adsorption to the polymer surfaces does not affect the accuracy and precision. Analysis of a sample containing naturally occurring endotoxin with the developed microfluidic microplate yielded comparable results to the conventional testing method. A test with eight commercially available pharmaceuticals was found to pass all requirements for bacterial endotoxin testing as specified in the United States Pharmacopeia. The automated endotoxin testing system reveals specific advantages of centrifugal microfluidics for analytical biochemistry applications. Small liquid volumes are handled (metered, mixed, and aliquoted) in a very precise, highly integrated, and highly parallel manner within mass-fabricated microplates.

Failure mode and effect analysis in human islet isolation: from the theoretical to the practical risk

This study aimed to assess the global mapping risk of human islet isolation, using a failure mode and effect analysis (FMEA), and highlight the impact of quality assurance procedures on the risk level of criticality. Risks were scored using the risk priority number (RPN) scoring method. The risk level of criticality was made based on RPN and led to risk classification (low to critical). A raw risk analysis and a risk control analysis (with control means and quality assurance performance) were undertaken. The process of human islet isolation was divided into 11 steps, and 230 risks were identified. Analysis of the highest RPN of each of the 11 steps showed that the 4 highest risks were related to the pancreas digestion and islet purification stages. After implementation of reduction measures and controls, critical and severe risks were reduced by 3-fold and by 2-fold, respectively, so that 90% of risks could be considered as low to moderate. FMEA has proven to be a powerful approach for the identification of weaknesses in the islet isolation processes. The results demonstrated the importance of staff qualification and continuous training and supported the contribution of the quality assurance system to risk reduction.

Cell-Based Therapy Manufacturing in Stirred Suspension Bioreactor: Thoughts for cGMP Compliance

Cell-based therapy (CBT) is attracting much attention to treat incurable diseases. In recent years, several clinical trials have been conducted using human pluripotent stem cells (hPSCs), and other potential therapeutic cells. Various private- and government-funded organizations are investing in finding permanent cures for diseases that are difficult or expensive to treat over a lifespan, such as age-related macular degeneration, Parkinson’s disease, or diabetes, etc. Clinical-grade cell manufacturing requiring current good manufacturing practices (cGMP) has therefore become an important issue to make safe and effective CBT products. Current cell production practices are adopted from conventional antibody or protein production in the pharmaceutical industry, wherein cells are used as a vector to produce the desired products. With CBT, however, the “cells are the final products” and sensitive to physico- chemical parameters and storage conditions anywhere between isolation and patient administration. In addition, the manufacturing of cellular products involves multi-stage processing, including cell isolation, genetic modification, PSC derivation, expansion, differentiation, purification, characterization, cryopreservation, etc. Posing a high risk of product contamination, these can be time- and cost- prohibitive due to maintenance of cGMP. The growing demand of CBT needs integrated manufacturing systems that can provide a more simple and cost-effective platform. Here, we discuss the current methods and limitations of CBT, based upon experience with biologics production. We review current cell manufacturing integration, automation and provide an overview of some important considerations and best cGMP practices. Finally, we propose how multi-stage cell processing can be integrated into a single bioreactor, in order to develop streamlined cGMP-compliant cell processing systems.

Laboratory-Scale Lentiviral Vector Production and Purification for Enhanced Ex Vivo and In Vivo Genetic Engineering

Lentiviral vectors (LVs) are increasingly employed in gene and cell therapy. Standard laboratory production of LVs is not easily scalable, and research-grade LVs often contain contaminants that can interfere with downstream applications. Moreover, purified LV production pipelines have been developed mainly for costly, large-scale, clinical-grade settings. Therefore, a standardized and cost-effective process is still needed to obtain efficient, reproducible, and properly executed experimental studies and preclinical development of ex vivo and in vivo gene therapies, as high infectivity and limited adverse reactions are important factors potentially influencing experimental outcomes also in preclinical settings. We describe here an optimized laboratory-scale workflow whereby an LV-containing supernatant is purified and concentrated by sequential chromatographic steps, obtaining biologically active LVs with an infectious titer and specific activity in the order of 10⁹ transducing unit (TU)/mL and 5 × 10⁴ TU/ng of HIV Gag p24, respectively. The purification workflow removes >99% of the starting plasmid, DNA, and protein impurities, resulting in higher gene transfer and editing efficiency in severe combined immunodeficiency (SCID)-repopulating hematopoietic stem and progenitor cells (HSPCs) ex vivo, as well as reduced activation of inflammatory responses ex vivo and in vivo as compared to TU-matched, laboratory-grade vectors. Our results highlight the value of accessible purified LV production for experimental studies and preclinical testing.

Validation and applicability of an alternative method for dialysis water and dialysate quality analysis

INTRODUCTION

In hemodialysis, patients are exposed to a large volume of water, which may lead to fatal risks if not meeting quality standards. This study aimed to validate an alternative method for monitoring microbiological quality of treated water and assess its applicability in dialysis and dialysate analysis, to allow corrective actions in real-time.

METHODS

Validation and applicability were analyzed by conventional and alternative methods. For validation, E. coli standard endotoxin was diluted with apyrogenic water in five concentrations. For the applicability analysis, treated water for dialysis was collected from different points in the treatment system (reverse osmosis, drainage canalization at the storage tank bottom, reuse, and loop), and dialysate was collected from four machines located in different rooms in the hemodialysis sector.

RESULTS

The validation results were in accordance with the Brazilian Pharmacopoeia acceptance criteria, except for the last two concentrations analyzed. In addition, the ruggedness criterion performed under the US Pharmacopoeia was in agreement with the results.

DISCUSSION

A limiting factor in the applicability analysis was the absence of the endotoxin maximum permitted level in dialysate by the Brazilian legislation. When comparing the analysis time, the alternative method was more time-consuming than the conventional one. This suggests that the alternative method is effective in the case of few analyses, that is, real-time analyses, favoring corrective actions promptly. On the other hand, it does not support the implementation of the alternative method in a laboratory routine due to the high demand for analyses.

Effects of butyrate supplementation on blood glucagon-like peptide-2 concentration and gastrointestinal functions of lactating dairy cows fed diets differing in starch content

The objective of this study was to evaluate effects of butyrate supplementation on plasma concentration of glucagon-like peptide-2 (GLP-2), apparent total-tract digestibility, and responses to a grain challenge of lactating dairy cows fed diets differing in starch content. Eight Holstein cows averaging 58.6 ± 9.96 d in milk (4 primiparous cows fitted with rumen cannula and 4 multiparous intact cows) were blocked by parity and assigned to one of two 4 × 4 Latin squares balanced for carryover effects with a 2 × 2 factorial arrangement of treatments. Treatments were dietary starch content [20.6 vs. 27.5%, respectively, for low starch (LS) and high starch (HS)] and butyrate supplementation (butyrate vs. control) with 21-d periods. Butyrate was provided as Gustor BP70 WS (Norel, S.A., Madrid, Spain), containing 70% sodium butyrate and 30% fatty acid mixture, at 2% of dietary dry matter (providing butyrate at 1.1% of dietary dry matter), and control premix contained 70% wheat bran and 30% fatty acid mixture. Feeds, orts, and fecal samples were collected from d 17 to 19 to determine apparent total-tract nutrient digestibility. Blood and rumen fluid samples were collected on d 19. The baseline of dry matter intake (DMI) was determined as average DMI from d 17 to 19 for each cow, and cows were feed-restricted at 60% of the baseline DMI on d 20, and a grain challenge was conducted by providing steam-flaked corn grain at 0.6% of body weight, on an as-fed basis, in addition to each treatment diet on d 21, and blood and ruminal fluid samples were collected. The interaction of dietary starch content by butyrate supplementation was significant for plasma GLP-2 concentration, being greater for cows fed butyrate with the HS diet than those fed the other 3 diets. Cows fed butyrate increased n-butyrate concentration in the ruminal fluid and tended to increase dry matter and organic matter digestibility compared with the control. During the grain challenge, rumen endotoxin concentration increased over time and was higher for cows fed the HS diets compared with those fed LS diets. However, response variables related to inflammation were not affected by the grain challenge. However, serum haptoglobin, lipopolysaccharide-binding protein, and serum amyloid-A concentrations were greater for cows fed butyrate with the LS diet, but not for those fed the HS diet. These results indicate that butyrate supplementation may increase plasma GLP-2 concentration for cows fed HS diets, and total-tract digestibility regardless of dietary starch content. However, butyrate supplementation did not mitigate inflammation in this study.

Determination of the Structural Integrity and Stability of Polysialic Acid during Alkaline and Thermal Treatment

Polysialic acid (polySia) is a linear homopolymer of varying chain lengths that exists mostly on the outer cell membrane surface of certain bacteria, such as Escherichia coli (E. coli) K1. PolySia, with an average degree of polymerization of 20 (polySia avDP20), possesses material properties that can be used for therapeutic applications to treat inflammatory neurodegenerative diseases. The fermentation of E. coli K1 enables the large-scale production of endogenous long-chain polySia (DP ≈ 130) (LC polySia), from which polySia avDP20 can be manufactured using thermal hydrolysis. To ensure adequate biopharmaceutical quality of the product, the removal of byproducts and contaminants, such as endotoxins, is essential. Recent studies have revealed that the long-term incubation in alkaline sodium hydroxide (NaOH) solutions reduces the endotoxin content down to 3 EU (endotoxin units) per mg, which is in the range of pharmaceutical applications. In this study, we analyzed interferences in the intramolecular structure of polySia caused by harsh NaOH treatment or thermal hydrolysis. Nuclear magnetic resonance (NMR) spectroscopy revealed that neither the incubation in an alkaline solution nor the thermal hydrolysis induced any chemical modification. In addition, HPLC analysis with a preceding 1,2-diamino-4,5-methylenedioxybenzene (DMB) derivatization demonstrated that the alkaline treatment did not induce any hydrolytic effects to reduce the maximum polymer length and that the controlled thermal hydrolysis reduced the maximum chain length effectively, while cost-effective incubation in alkaline solutions had no adverse effects on LC polySia. Therefore, both methods guarantee the production of high-purity, low-molecular-weight polySia without alterations in the structure, which is a prerequisite for the submission of a marketing authorization application as a medicinal product. However, a specific synthesis of low-molecular-weight polySia with defined chain lengths is only possible to a limited extent.

Design and Challenges of Radiopharmaceuticals

This review describes general concepts with regard to radiopharmaceuticals for diagnostic or therapeutic applications that help to understand the specific challenges encountered during the design, (radio)synthesis, in vitro and in vivo evaluation and clinical translation of novel radiopharmaceuticals. The design of a radiopharmaceutical requires upfront decisions with regard to combining a suitable vector molecule with an appropriate radionuclide, considering the type and location of the molecular target, the desired application, and the time constraints imposed by the relatively short half-life of radionuclides. Well-designed in vitro and in vivo experiments allow nonclinical validation of radiotracers. Ultimately, in combination with a limited toxicology package, the radiotracer becomes a radiopharmaceutical for clinical evaluation, produced in compliance with regulatory requirements for medicines for intravenous (IV) injection.

Relationship between bronchoalveolar lavage fluid and plasma endotoxin activity in calves with bronchopneumonia

The aim of this study was to investigate the relationship between the endotoxin activity in plasma and that in bronchoalveolar lavage fluid (BALF) in bronchopneumonia. Thirty-three calves were included in this study (17 healthy calves and 16 calves with respiratory disease). In the calves with bronchopneumonia, the median endotoxin activity in plasma (0.437 EU/ml, P<0.001) and BALF (29.45 EU/ml, P<0.001) was significantly higher than in the control calves. Plasma endotoxin activity was significantly and positively correlated with that in BALF (r²=0.900, P<0.001). Based on the receiver operating characteristics curves, we propose a diagnostic cutoff point for plasma endotoxin activity (0.104 EU/ml, AUC=0.914, P<0.001, Se 81.3% and Sp 82.4%) for identification of bronchopneumonia in calves which could die within a week.

Critical testing and parameters for consideration when manufacturing and evaluating tumor-associated antigen-specific T cells

The past year has seen remarkable translation of cellular and gene therapies, with U.S. Food and Drug Administration (FDA) approval of three chimeric antigen receptor (CAR) T-cell products, multiple gene therapy products, and the initiation of countless other pivotal clinical trials. What makes these new drugs most remarkable is their path to commercialization: they have unique requirements compared with traditional pharmaceutical drugs and require different potency assays, critical quality attributes and parameters, pharmacological and toxicological data, and in vivo efficacy testing. What's more, each biologic requires its own unique set of tests and parameters. Here we describe the unique tests associated with ex vivo-expanded tumor-associated antigen T cells (TAA-T). These tests include functional assays to determine potency, specificity, and identity; tests for pathogenic contaminants, such as bacteria and fungus as well as other contaminants such as Mycoplasma and endotoxin; tests for product characterization, tests to evaluate T-cell persistence and product efficacy; and finally, recommendations for critical quality attributes and parameters associated with the expansion of TAA-Ts.

Biomanufacturing of Therapeutic Cells: State of the Art, Current Challenges, and Future Perspectives

Stem cells and other functionally defined therapeutic cells (e.g., T cells) are promising to bring hope of a permanent cure for diseases and disorders that currently cannot be cured by conventional drugs or biological molecules. This paradigm shift in modern medicine of using cells as novel therapeutics can be realized only if suitable manufacturing technologies for large-scale, cost-effective, reproducible production of high-quality cells can be developed. Here we review the state of the art in therapeutic cell manufacturing, including cell purification and isolation, activation and differentiation, genetic modification, expansion, packaging, and preservation. We identify current challenges and discuss opportunities to overcome them such that cell therapies become highly effective, safe, and predictively reproducible while at the same time becoming affordable and widely available.

Plasma endotoxin activity in Eastern grey kangaroos (Macropus giganteus) with lumpy jaw disease

Progressive pyogranulomatous osteomyelitis involving the mandible or maxilla of captive macropods, referred to as "Lumpy jaw disease (LJD)", is one of the most significant causes of illness and death in captive macropods. The aim of the present study was to evaluate the relationship between the severity of LJD and plasma endotoxin activity in kangaroos. Plasma samples obtained from moderate (n=24) and severe LJD (n=12), and healthy kangaroos (n=46), were diluted 1:20 in endotoxin-free water and heated to 80°C for 10 min. Plasma endotoxin activity was measured using the Limulus amebocyte lysate (LAL)-kinetic turbidimetric (KT) assay. Plasma endotoxin activity was higher in kangaroos with severe LJD (0.199 ± 0.157 EU/ml) than in those with moderate LJD (0.051 ± 0.012 EU/ml, P<0.001) and healthy controls (0.057 ± 0.028 EU/ml, P<0.001). Our results suggest that the severity of LJD in captive macropods may be related to the plasma endotoxin activity.

Plasma endotoxin activity in kangaroos with oral necrobacillosis (lumpy jaw disease) using an automated handheld testing system

The aim of the present study was to evaluate the reliability and effectiveness of directly determining endotoxin activity in plasma samples from kangaroos with lumpy jaw disease (LJD, n=15) and healthy controls (n=12). Prior to the present study, the ability of the commercially available automated handheld portable test system (PTS^TM) to detect endotoxin activity in kangaroo plasma was compared with that of the traditional LAL-kinetic turbidimetric (KT) assay. Plasma samples, which were obtained from endotoxin-challenged cattle, were diluted 1:20 in endotoxin-free water and heated to 80°C for 10 min. The performance of the PTS^TM was not significantly different from that of the traditional LAL-based assay. The data obtained using PTS^TM correlated with those using KT (r²=0.963, P<0.001). These findings indicated that the PTS^TM is applicable as a simplified system to assess endotoxin activity in macropods. In the present study, we demonstrated the diagnostic value of plasma endotoxin activity in kangaroos with systemic inflammation caused by oral necrobacillosis and identified plasma endotoxin activity as a sensitive marker of systemic inflammation in kangaroos with LJD. Based on ROC curves, we proposed a diagnostic cut-off point for endotoxin activity of >0.22 EU/ml for the identification of LJD. Our results indicate that the assessment of plasma endotoxin activity is a promising diagnostic tool for determining the outcome of LJD in captive macropods.

Evaluation of a portable test system for assessing endotoxin activity in raw milk

The aim of the present study was to compare endotoxin activities detected in raw milk samples obtained from cattle by a commercially available portable test system (PTS) and traditional microplate limulus amebocyte lysate (LAL)-based assay, which determined activities using a kinetic turbidimetric (KT) assay. Raw milk samples were obtained from 53 and 12 dairy cattle without and with clinical mastitis, respectively. Comparison between the KT and PTS was performed by the Friedman test. The Pearson product moment correlation coefficients were calculated to evaluate associations between any two continuous variables. Linear regression model analysis was also performed to obtain the equation describing the relationship between PTS and KT assay. The endotoxin activities detected in 200- or 400-fold diluted milk samples were similar between PTS and KT assay, whereas a significant difference was observed in 100-fold diluted milk (P<0.001). The results obtained from 200- (r(2)=0.778, P<0.001) and 400-fold diluted milk samples (r(2)=0.945, P<0.001) using PTS correlated with those using KT assay. The median milk endotoxin activities in Gram-positive and Gram-negative clinical mastitis cows were 0.655 and 11,523.5 EU/ml, respectively. The results of the present study suggest that PTS as a simple and easy test to assess endotoxin activity in raw milk is efficient, simple and reproducible.

Detecting endotoxin activity in bovine serum using an automated testing system

The aim of the present study was to compare the ability of the commercially available portable test system (PTS^TM) to detect endotoxin activity in bovine serum, with that of the traditional LAL-kinetic turbidimetric (KT) and chromogenic (KC) assays. Prior to testing, serum samples, which were obtained from endotoxin-challenged cattle, were diluted 1:20 in endotoxin-free water and heated to 80°C for 10 min. The performance of the PTS^TM was not significantly different from that of the traditional LAL-based assays. The results using PTS^TM correlated with those using KT (r²=0.963, P<0.001) or KC assays (r²=0.982, P<0.001). Based on these findings, the PTS^TM could be applied as a simplified system to assess endotoxin activity in bovine serum.

Manufacture of tumor- and virus-specific T lymphocytes for adoptive cell therapies

Adoptive transfer of tumor-infiltrating lymphocytes (TILs) and genetically engineered T lymphocytes expressing chimeric antigen receptors (CARs) or conventional alpha/beta T-cell receptors (TCRs), collectively termed adoptive cell therapy (ACT), is an emerging novel strategy to treat cancer patients. Application of ACT has been constrained by the ability to isolate and expand functional tumor-reactive T cells. The transition of ACT from a promising experimental regimen to an established standard of care treatment relies largely on the establishment of safe, efficient, robust and cost-effective cell manufacturing protocols. The manufacture of cellular products under current good manufacturing practices (cGMPs) has a critical role in the process. Herein, we review current manufacturing methods for the large-scale production of clinical-grade TILs, virus-specific and genetically modified CAR or TCR transduced T cells in the context of phase I/II clinical trials as well as the regulatory pathway to get these complex personalized cellular products to the clinic.

Determination of ATP-activity as a useful tool for monitoring microbial load in aqueous humidifier samples

Air humidifier water tanks are potential sources of microbial contaminants. Aerosolization of these contaminants is associated with the development of airway and lung diseases; therefore, implementation of preventive strategies including monitoring of the microbial contamination is recommended. So far, culture-based methods that include measuring colony forming units (CFU) are widely used to monitor microbial load. However, these methods are time consuming and have considerable drawbacks. As a result, alternative methods are needed which provide not only clear and accurate results concerning microbial load in water samples, but are also rapid and easy to use in the field. This paper reports on a rapid test for ATP quantification as an alternative method for microbial monitoring, including its implementation, validation and application in the field. For this purpose, 186 water samples were characterized with different methods, which included ATP analysis, culture-based methods, endotoxin activity (common and rapid test), pyrogenic activity and number of particles. Half of the samples was measured directly in the field and the other half one day later in the laboratory. The results of both tests are highly correlated. Furthermore, to check how representative the result from one sample of a water source is, a second sample of the same water tank were collected and measured. Bioluminescence results of the undiluted samples covered a range between 20 and 25,000 relative light units (RLU) and correlated with the results obtained using the other methods. The highest correlation was found between bioluminescence and endotoxin activity (rs=0.79) as well as pyrogenic activity (rs=0.75). Overall, the results of this study indicate that ATP measurement using bioluminescence is a suitable tool to obtain rapid, reproducible and sensitive information on the microbial load of water samples, and is suitable to use in the field. However, to use ATP measurement as an indicator of water quality, criteria of assessment has to be discussed.

Development of a biological protocol for endotoxin detection using quartz crystal microbalance (QCM)

In this paper, a biological protocol for endotoxin detection has been developed and optimized by quartz crystal microbalance (QCM). The parameters involved in the formation of the self-assembled monolayer (SAM) have been analyzed, and a study of the pH of the ligand buffer has been performed in order to find the best condition for the ligand immobilization and, in consequence, for the endotoxin detection. The detection limit obtained with the characterized biological protocol corresponds to 1.90 μg/ml. The effectiveness of the optimized biological protocol has been analyzed by cyclic voltammetry analysis.

Production and quality control of [(90)Y]DOTATOC for treatment of metastatic neuroendocrine tumors: results of 85 syntheses

The aim of this paper was to describe the optimized labeling protocol and quality control measures used in the production of [(90)Y]DOTATOC, starting from three different radioactivity levels to treat one, two, or three patients per therapeutic session. We investigated three different starting radioactivity levels. For the low radioactivity preparation we used 5138±280 MBq of [Y] isotope, for the medium radioactivity preparation we used 8893±900 MBq, and for the high radioactivity preparation we used 11250±715 MBq. The radiochemical purity levels for the low radioactivity preparation, medium radioactivity preparation, and high radioactivity preparation were 99.95±0.09, 99.84±0.34, and 99.84±0.53%, respectively, and the radiochemical yields of the labeling procedures were 77.52±1.28, 75.53±3.72, and 78.00±3.20%, respectively. Media fill validation of the process was performed, and the parameters of pH, bacterial endotoxins, sterility, and osmolality were tested at process control. All radiopharmaceutical preparations satisfied the predetermined specifications fixed in our protocol regardless of the starting radioactivity level. The validation of the method guaranteed the safety and quality of the final products, contributing to providing the basis for constructing an informative and successful clinical trial.

Factors affecting the turnaround time for manufacturing, testing, and release of cellular therapy products prepared at multiple sites in support of multicenter cardiovascular regenerative medicine protocols: a Cardiovascular Cell Therapy Research Network (CCTRN) study

BACKGROUND

Cellular therapy studies are often conducted at multiple clinical sites to accrue larger patient numbers. In many cases this necessitates use of localized good manufacturing practices facilities to supply the cells. To assure consistent quality, oversight by a quality assurance group is advisable. In this study we report the findings of such a group established as part of the Cardiovascular Cell Therapy Research Network (CCTRN) studies involving use of autologous bone marrow mononuclear cells (ABMMCs) to treat myocardial infarction and heart failure.

STUDY DESIGN AND METHODS

Factors affecting cell manufacturing time were studied in 269 patients enrolled on three CCTRN protocols using automated cell processing system (Sepax, Biosafe SA)-separated ABMMCs. The cells were prepared at five good manufacturing practices cell processing facilities and delivered to local treatment sites or more distant satellite centers.

RESULTS

Although the Sepax procedure takes only 90 minutes, the total time for processing was approximately 7 hours. Contributing to this were incoming testing and device preparation, release testing, patient randomization, and product delivery. The mean out-of-body time (OBT), which was to be less than 12 hours, averaged 9 hours. A detailed analysis of practices at each center revealed a variety of factors that contributed to this OBT.

CONCLUSION

We conclude that rapid cell enrichment procedures may give a false impression of the time actually required to prepare a cellular therapy product for release and administration. Institutional procedures also differ and can contribute to delays; however, in aggregate it is possible to achieve an overall manufacturing and testing time that is similar at multiple facilities.

Advances in the in-field detection of microorganisms in ice

The historic view of ice-bound ecosystems has been one of a predominantly lifeless environment, where microorganisms certainly exist but are assumed to be either completely inactive or in a state of long-term dormancy. However, this standpoint has been progressively overturned in the past 20years as studies have started to reveal the importance of microbial life in the functioning of these environments. Our present knowledge of the distribution, taxonomy, and metabolic activity of such microbial life has been derived primarily from laboratory-based analyses of collected field samples. To date, only a restricted range of life detection and characterization techniques have been applied in the field. Specific examples include direct observation and DNA-based techniques (microscopy, specific stains, and community profiling based on PCR amplification), the detection of biomarkers (such as adenosine triphosphate), and measurements of metabolism [through the uptake and incorporation of radiolabeled isotopes or chemical alteration of fluorescent substrates (umbelliferones are also useful here)]. On-going improvements in technology mean that smaller and more robust life detection and characterization systems are continually being designed, manufactured, and adapted for in-field use. Adapting technology designed for other applications is the main source of new methodology, and the range of techniques is currently increasing rapidly. Here we review the current use of technology and techniques to detect and characterize microbial life within icy environments and specifically its deployment to in-field situations. We discuss the necessary considerations, limitations, and adaptations, review emerging technologies, and highlight the future potential. Successful application of these new techniques to in-field studies will certainly generate new insights into the way ice bound ecosystems function.

Intestinal decontamination inhibits TLR4 dependent fibronectin-mediated cross-talk between stellate cells and endothelial cells in liver fibrosis in mice

BACKGROUND & AIMS

Liver fibrosis is associated with angiogenesis and leads to portal hypertension. Certain antibiotics reduce complications of liver failure in humans, however, the effects of antibiotics on the pathologic alterations of the disease are not fully understood. The aim of this study was to test whether the non-absorbable antibiotic rifaximin could attenuate fibrosis progression and portal hypertension in vivo, and explore potential mechanisms in vitro.

METHODS

The effect of rifaximin on portal pressure, fibrosis, and angiogenesis was examined in wild type and Toll-like receptor 4 (TLR4) mutant mice after bile duct ligation (BDL). In vitro studies were carried out to evaluate the effect of the bacterial product and TLR agonist lipopolysaccharide (LPS) on paracrine interactions between hepatic stellate cells (HSC) and liver endothelial cells (LEC) that lead to fibrosis and portal hypertension.

RESULTS

Portal pressure, fibrosis, and angiogenesis were significantly lower in BDL mice receiving rifaximin compared to BDL mice receiving vehicle. Studies in TLR4 mutant mice confirmed that the effect of rifaximin was dependent on LPS/TLR4 pathway. Fibronectin (FN) was increased in the BDL liver and was reduced by rifaximin administration and thus, was explored further in vitro as a potential mediator of paracrine interactions of HSC and LEC. In vitro, LPS promoted FN production from HSC. Furthermore, HSC-derived FN promoted LEC migration and angiogenesis.

CONCLUSIONS

These studies expand our understanding of the relationship of intestinal microbiota with fibrosis development by identifying FN as a TLR4 dependent mediator of the matrix and vascular changes that characterize cirrhosis.

Development of an electrochemical Limulus amebocyte lysate assay technique for portable and highly sensitive endotoxin sensor

Here, we report the development of an electrochemical detection method for endotoxin based on the Limulus amebocyte lysate (LAL) assay. A mixture of LAL reagent and endotoxin sample solution was incubated for 1 h. The endotoxin activated a cascade reaction of zymogens contained in the LAL to generate p-nitroaniline (pNA) which was then electrochemically detected by differential pulse voltammetry (DPV). The generated pNA gave a clear peak at –0.75 V vs. silver/silver chloride (Ag/AgCl), which increased with the concentration of endotoxin in the LAL assay solution. This DPV detection was performed using an electrode chip device fabricated from a diamond-like carbon-coated glass substrate. This chip device could detect as low as 10 endotoxin units l−1 at room temperature within 1 h. This novel electrochemical method for the detection of endotoxin appears promising for the development of compact, low-cost and easy-to-use sensors for on-site monitoring of potentially contaminated medical supplies, including dialysis fluid, transplanted tissue and culture medium for assisted reproduction.

Quality by design and process analytical technology for sterile products--where are we now?

Quality by design (QbD) and process analytical technology (PAT) have become priorities for the Center for Drug Evaluation and Research (CDER) at the Food and Drug Administration (FDA). Numerous recent initiatives within CDER and FDA have had the objective of encouraging the pharmaceutical industry to utilize QbD and PAT in their product development and manufacturing processes. Although sterile products may be a minority compared to non-sterile dosage forms (e.g., solid orals), their absolute requirement for sterility make design and control of the manufacturing processes extremely critical. This emphasis on the manufacturing process makes the sterile drug product an obvious target for QbD and PAT. Although the FDA encourages QbD submissions, the utilization of QbD and PAT for sterile products so far is still limited. This paper will examine the present state of QbD and PAT for sterile products and review some examples currently in use. Additional potential applications of QbD and PAT for sterile product development and manufacturing will also be discussed.

Multicenter cell processing for cardiovascular regenerative medicine applications: the Cardiovascular Cell Therapy Research Network (CCTRN) experience

Abstract Background aims. Multicenter cellular therapy clinical trials require the establishment and implementation of standardized cell-processing protocols and associated quality control (QC) mechanisms. The aims here were to develop such an infrastructure in support of the Cardiovascular Cell Therapy Research Network (CCTRN) and to report on the results of processing for the first 60 patients. Methods. Standardized cell preparations, consisting of autologous bone marrow (BM) mononuclear cells, prepared using a Sepax device, were manufactured at each of the five processing facilities that supported the clinical treatment centers. Processing staff underwent centralized training that included proficiency evaluation. Quality was subsequently monitored by a central QC program that included product evaluation by the CCTRN biorepositories. Results. Data from the first 60 procedures demonstrated that uniform products, that met all release criteria, could be manufactured at all five sites within 7 h of receipt of BM. Uniformity was facilitated by use of automated systems (the Sepax for processing and the Endosafe device for endotoxin testing), standardized procedures and centralized QC. Conclusions. Complex multicenter cell therapy and regenerative medicine protocols can, where necessary, successfully utilize local processing facilities once an effective infrastructure is in place to provide training and QC.

Manufacturing validation of biologically functional T cells targeted to CD19 antigen for autologous adoptive cell therapy

On the basis of promising preclinical data demonstrating the eradication of systemic B-cell malignancies by CD19-targeted T lymphocytes in vivo in severe combined immunodeficient-beige mouse models, we are launching phase I clinical trials in patients with chronic lymphocytic leukemia (CLL) and acute lymphoblastic leukemia. We present here the validation of the bioprocess which we developed for the production and expansion of clinical grade autologous T cells derived from patients with CLL. We demonstrate that T cells genetically modified with a replication-defective gammaretroviral vector derived from the Moloney murine leukemia virus encoding a chimeric antigen receptor (CAR) targeted to CD19 (1928z) can be expanded with Dynabeads CD3/CD28. This bioprocess allows us to generate clinical doses of 1928z+ T cells in approximately 2 to 3 weeks in a large-scale semiclosed culture system using the Wave Bioreactor. These 1928z+ T cells remain biologically functional not only in vitro but also in severe combined immunodeficient-beige mice bearing disseminated tumors. The validation requirements in terms of T-cell expansion, T-cell transduction with the 1928z CAR, biologic activity, quality control testing, and release criteria were met for all 4 validation runs using apheresis products from patients with CLL. Additionally, after expansion of the T cells, the diversity of the skewed Vbeta T-cell receptor repertoire was significantly restored. This validated process will be used in phase I clinical trials in patients with chemorefractory CLL and in patients with relapsed acute lymphoblastic leukemia. It can also be adapted for other clinical trials involving the expansion and transduction of patient or donor T cells using any CAR or T-cell receptor.