Techno-economic modeling and assessment of cultivated meat: Impact of production bioreactor scale.

Increases in global meat demands cannot be sustainably met with current methods of livestock farming, which has a substantial impact on greenhouse gas emissions, land use, water consumption, and farm animal welfare. Cultivated meat is a rapidly advancing technology that produces meat products by proliferating and differentiating animal stem cells in large bioreactors, avoiding conventional live-animal farming. While many companies are working in this area, there is a lack of existing infrastructure and experience at commercial scale, resulting in many technical bottlenecks such as scale-up of cell culture and media availability and costs. In this study, we evaluate theoretical cultivated beef production facilities with the goal of envisioning an industry with multiple facilities to produce in total 100,000,000 kg of cultured beef per year or ~0.14% of the annual global beef production. Using the computer-aided process design software, SuperPro Designer®, facilities are modeled to create a comprehensive analysis to highlight improvements that can lower the cost of such a production system and allow cultivated meat products to be competitive. Three facility scenarios are presented with different sized production reactors; ~42,000 L stirred tank bioreactor (STR) with a base case cost of goods sold (COGS) of $35/kg, ~211,000 L STR with a COGS of $25/kg, and ~262,000 L airlift reactor (ALR) with a COGS of $17/kg. This study outlines how advances in scaled up bioreactors, alternative bioreactor designs, and decreased media costs are necessary for commercialization of cultured meat products.

SARS-CoV-2 spike binding to ACE2 is stronger and longer ranged due to glycan interaction.

Highly detailed steered molecular dynamics simulations are performed on differently glycosylated receptor binding domains of the severe acute respiratory syndrome coronavirus-2 spike protein. The binding strength and the binding range increase with glycosylation. The interaction energy rises very quickly when pulling the proteins apart and only slowly drops at larger distances. We see a catch-slip-type behavior whereby interactions during pulling break and are taken over by new interactions forming. The dominant interaction mode is hydrogen bonds, but Lennard-Jones and electrostatic interactions are relevant as well.

Functionalizing silica sol-gel with entrapped plant virus-based immunosorbent nanoparticles.

Advancements in understanding and engineering of virus-based nanomaterials (VBNs) for biomedical applications motivate a need to explore the interfaces between VBNs and other biomedically-relevant chemistries and materials. While several strategies have been used to investigate some of these interfaces with promising initial results, including VBN-containing slow-release implants and VBN-activated bioceramic bone scaffolds, there remains a need to establish VBN-immobilized three dimensional materials that exhibit improved stability and diffusion characteristics for biosensing and other analyte-capture applications. Silica sol-gel chemistries have been researched for biomedical applications over several decades and are well understood; various cellular organisms and biomolecules (e.g., bacteria, algae, enzymes) have been immobilized in silica sol-gels to improve viability, activity, and form factor (i.e., ease of use). Here we present the immobilization of an antibody-binding VBN in silica sol-gel by pore confinement. We have shown that the resulting system is sufficiently diffuse to allow antibodies to migrate in and out of the matrix. We also show that the immobilized VBN is capable of antibody binding and elution functionality under different buffer conditions for multiple use cycles. The promising results of the VBN and silica sol-gel interface indicate a general applicability for VBN-based bioseparations and biosensing applications.

Analysis of Variability of Functionals of Recombinant Protein Production Trajectories Based on Limited Data.

Making statistical inference on quantities defining various characteristics of a temporally measured biochemical process and analyzing its variability across different experimental conditions is a core challenge in various branches of science. This problem is particularly difficult when the amount of data that can be collected is limited in terms of both the number of replicates and the number of time points per process trajectory. We propose a method for analyzing the variability of smooth functionals of the growth or production trajectories associated with such processes across different experimental conditions. Our modeling approach is based on a spline representation of the mean trajectories. We also develop a bootstrap-based inference procedure for the parameters while accounting for possible multiple comparisons. This methodology is applied to study two types of quantities-the "time to harvest" and "maximal productivity"-in the context of an experiment on the production of recombinant proteins. We complement the findings with extensive numerical experiments comparing the effectiveness of different types of bootstrap procedures for various tests of hypotheses. These numerical experiments convincingly demonstrate that the proposed method yields reliable inference on complex characteristics of the processes even in a data-limited environment where more traditional methods for statistical inference are typically not reliable.

Contributions of the international plant science community to the fight against human infectious diseases - part 1: epidemic and pandemic diseases.

Infectious diseases, also known as transmissible or communicable diseases, are caused by pathogens or parasites that spread in communities by direct contact with infected individuals or contaminated materials, through droplets and aerosols, or via vectors such as insects. Such diseases cause ˜17% of all human deaths and their management and control places an immense burden on healthcare systems worldwide. Traditional approaches for the prevention and control of infectious diseases include vaccination programmes, hygiene measures and drugs that suppress the pathogen, treat the disease symptoms or attenuate aggressive reactions of the host immune system. The provision of vaccines and biologic drugs such as antibodies is hampered by the high cost and limited scalability of traditional manufacturing platforms based on microbial and animal cells, particularly in developing countries where infectious diseases are prevalent and poorly controlled. Molecular farming, which uses plants for protein expression, is a promising strategy to address the drawbacks of current manufacturing platforms. In this review article, we consider the potential of molecular farming to address healthcare demands for the most prevalent and important epidemic and pandemic diseases, focussing on recent outbreaks of high-mortality coronavirus infections and diseases that disproportionately affect the developing world.

Contributions of the international plant science community to the fight against infectious diseases in humans-part 2: Affordable drugs in edible plants for endemic and re-emerging diseases.

The fight against infectious diseases often focuses on epidemics and pandemics, which demand urgent resources and command attention from the health authorities and media. However, the vast majority of deaths caused by infectious diseases occur in endemic zones, particularly in developing countries, placing a disproportionate burden on underfunded health systems and often requiring international interventions. The provision of vaccines and other biologics is hampered not only by the high cost and limited scalability of traditional manufacturing platforms based on microbial and animal cells, but also by challenges caused by distribution and storage, particularly in regions without a complete cold chain. In this review article, we consider the potential of molecular farming to address the challenges of endemic and re-emerging diseases, focusing on edible plants for the development of oral drugs. Key recent developments in this field include successful clinical trials based on orally delivered dried leaves of Artemisia annua against malarial parasite strains resistant to artemisinin combination therapy, the ability to produce clinical-grade protein drugs in leaves to treat infectious diseases and the long-term storage of protein drugs in dried leaves at ambient temperatures. Recent FDA approval of the first orally delivered protein drug encapsulated in plant cells to treat peanut allergy has opened the door for the development of affordable oral drugs that can be manufactured and distributed in remote areas without cold storage infrastructure and that eliminate the need for expensive purification steps and sterile delivery by injection.

Molecular pharming to support human life on the moon, mars, and beyond.

Space missions have always assumed that the risk of spacecraft malfunction far outweighs the risk of human system failure. This assumption breaks down for longer duration exploration missions and exposes vulnerabilities in space medical systems. Space agencies can no longer reduce the majority of the human health and performance risks through crew members selection process and emergency re-supply or evacuation. No mature medical solutions exist to address this risk. With recent advances in biotechnology, there is promise for lessening this risk by augmenting a space pharmacy with a biologically-based space foundry for the on-demand manufacturing of high-value medical products. Here we review the challenges and opportunities of molecular pharming, the production of pharmaceuticals in plants, as the basis of a space medical foundry to close the risk gap in current space medical systems. Plants have long been considered to be an important life support object in space and can now also be viewed as programmable factories in space. Advances in molecular pharming-based space foundries will have widespread applications in promoting simple and accessible pharmaceutical manufacturing on Earth.

Production of recombinant butyrylcholinesterase from transgenic rice cell suspension cultures in a pilot-scale bioreactor.

Producing recombinant proteins in transgenic plant cell suspension cultures in bioreactors provides controllability, reproducibility, scalability, and low-cost production, although low yields remain the major challenge. The studies on scaling-up to pilot-scale bioreactors, especially in conventional stainless-steel stirred tank bioreactors (STB), to produce recombinant proteins in plant cell suspension cultures are very limited. In this study, we scaled-up the production of rice recombinant butyrylcholinesterase (rrBChE), a complex hydrolase enzyme that can be used to prophylactically and therapeutically treat against organophosphorus nerve agents and pesticide exposure, from metabolically regulated transgenic rice cell suspension cultures in a 40-L pilot-scale STB. Employing cyclical operation together with a simplified-process operation (controlling gas sparging rate rather than dissolved oxygen and allowing natural sugar depletion) identified in lab-scale (5 L) bioreactor studies, we found a consistent maximum total active rrBChE production level of 46-58 µg/g fresh weight in four cycles over 82 days of semicontinuous operation. Additionally, maintaining the overall volumetric oxygen mass transfer coefficient (kL a) in the pilot-scale STB to be equivalent to the lab-scale STB improves the maximum total active rrBChE production level and the maximum volumetric productivity to 85 µg/g fresh weight and 387 µg L-1 day-1 , respectively, which are comparable to the lab-scale culture. Here, we demonstrate pilot-scale bioreactor performance using a metabolically regulated transgenic rice cell culture for long-term, reproducible, and sustained production of rrBChE.

Technoeconomic analysis of semicontinuous bioreactor production of biopharmaceuticals in transgenic rice cell suspension cultures.

Biopharmaceutical protein production using transgenic plant cell bioreactor processes offers advantages over microbial and mammalian cell culture platforms in its ability to produce complex biologics with simple chemically defined media and reduced biosafety concerns. A disadvantage of plant cells from a traditional batch bioprocessing perspective is their slow growth rate which has motivated us to develop semicontinuous and/or perfusion processes. Although the economic benefits of plant cell culture bioprocesses are often mentioned in the literature, to our knowledge no rigorous technoeconomic models or analyses have been published. Here we present technoeconomic models in SuperPro Designer® for the large-scale production of recombinant butyrylcholinesterase (BChE), a prophylactic/therapeutic bioscavenger against organophosphate nerve agent poisoning, in inducible transgenic rice cell suspension cultures. The base facility designed to produce 25 kg BChE per year utilizing two-stage semicontinuous bioreactor operation manufactures a single 400 mg dose of BChE for $263. Semicontinuous operation scenarios result in 4-11% reduction over traditional two-stage batch operation scenarios. In addition to providing a simulation tool that will be useful to the plant-made pharmaceutical community, the model also provides a computational framework that can be used for other semicontinuous or batch bioreactor-based processes.

Effects of Kifunensine on Production and N-Glycosylation Modification of Butyrylcholinesterase in a Transgenic Rice Cell Culture Bioreactor.

The production and N-glycosylation of recombinant human butyrylcholinesterase (BChE), a model highly glycosylated therapeutic protein, in a transgenic rice cell suspension culture treated with kifunensine, a strong α-mannosidase I inhibitor, was studied in a 5 L bioreactor. A media exchange was performed at day 7 of cultivation by removing spent sugar-rich medium (NB+S) and adding fresh sugar-free (NB-S) medium to induce the rice α-amylase 3D (RAmy3D) promoter to produce rice recombinant human BChE (rrBChE). Using a 1.25X-concentrated sugar-free medium together with an 80% reduced working volume during the media exchange led to a total active rrBChE production level of 79 ± 2 µg (g FW)-1 or 7.5 ± 0.4 mg L-1 in the presence of kifunensine, which was 1.5-times higher than our previous bioreactor runs using normal sugar-free (NB-S) media with no kifunensine treatment. Importantly, the amount of secreted active rrBChE in culture medium was enhanced in the presence of kifunensine, comprising 44% of the total active rrBChE at day 5 following induction. Coomassie-stained SDS-PAGE gel and Western blot analyses revealed different electrophoretic migration of purified rrBChE bands with and without kifunensine treatment, which was attributed to different N-glycoforms. N-Glycosylation analysis showed substantially increased oligomannose glycans (Man5/6/7/8) in rrBChE treated with kifunensine compared to controls. However, the mass-transfer limitation of kifunensine was likely the major reason for incomplete inhibition of α-mannosidase I in this bioreactor study.

In Vivo Glycan Engineering via the Mannosidase I Inhibitor (Kifunensine) Improves Efficacy of Rituximab Manufactured in Nicotiana benthamiana Plants.

N-glycosylation has been shown to affect the pharmacokinetic properties of several classes of biologics, including monoclonal antibodies, blood factors, and lysosomal enzymes. In the last two decades, N-glycan engineering has been employed to achieve a N-glycosylation profile that is either more consistent or aligned with a specific improved activity (i.e., effector function or serum half-life). In particular, attention has focused on engineering processes in vivo or in vitro to alter the structure of the N-glycosylation of the Fc region of anti-cancer monoclonal antibodies in order to increase antibody-dependent cell-mediated cytotoxicity (ADCC). Here, we applied the mannosidase I inhibitor kifunensine to the Nicotiana benthamiana transient expression platform to produce an afucosylated anti-CD20 antibody (rituximab). We determined the optimal concentration of kifunensine used in the infiltration solution, 0.375 µM, which was sufficient to produce exclusively oligomannose glycoforms, at a concentration 14 times lower than previously published levels. The resulting afucosylated rituximab revealed a 14-fold increase in ADCC activity targeting the lymphoma cell line Wil2-S when compared with rituximab produced in the absence of kifunensine. When applied to the cost-effective and scalable N. benthamiana transient expression platform, the use of kifunensine allows simple in-process glycan engineering without the need for transgenic hosts.

Purification, characterization, and N-glycosylation of recombinant butyrylcholinesterase from transgenic rice cell suspension cultures.

Recombinant butyrylcholinesterase produced in a metabolically regulated transgenic rice cell culture (rrBChE) was purified to produce a highly pure (95%), active form of enzyme. The developed downstream process uses common manufacturing friendly operations including tangential flow filtration, anion-exchange chromatography, and affinity chromatography to obtain a process recovery of 42% active rrBChE. The purified rrBChE was then characterized to confirm its comparability to the native human form of the molecule (hBChE). The recombinant and native enzyme demonstrated comparable enzymatic behavior and had an identical amino acid sequence. However, rrBChE differs in that it contains plant-type complex N-glycans, including an α-1,3 linked core fucose, and a ß-1,2 xylose, and lacking a terminal sialic acid. Despite this difference, rrBChE is demonstrated to be an effective stoichiometric bioscavenger for five different organophosphorous nerve agents in vitro. Together, the efficient downstream processing scheme and functionality of rrBChE confirm its promise as a cost-effective alternative to hBChE for prophylactic and therapeutic use.

Enhancement of Recombinant Protein Production in Transgenic Nicotiana benthamiana Plant Cell Suspension Cultures with Co-Cultivation of Agrobacterium Containing Silencing Suppressors.

We have previously demonstrated that the inducible plant viral vector (CMViva) in transgenic plant cell cultures can significantly improve the productivity of extracellular functional recombinant human alpha-1-antiryspin (rAAT) compared with either a common plant constitutive promoter (Cauliflower mosaic virus (CaMV) 35S) or a chemically inducible promoter (estrogen receptor-based XVE) system. For a transgenic plant host system, however, viral or transgene-induced post-transcriptional gene silencing (PTGS) has been identified as a host response mechanism that may dramatically reduce the expression of a foreign gene. Previous studies have suggested that viral gene silencing suppressors encoded by a virus can block or interfere with the pathways of transgene-induced PTGS in plant cells. In this study, the capability of nine different viral gene silencing suppressors were evaluated for improving the production of rAAT protein in transgenic plant cell cultures (CMViva, XVE or 35S system) using an Agrobacterium-mediated transient expression co-cultivation process in which transgenic plant cells and recombinant Agrobacterium carrying the viral gene silencing suppressor were grown together in suspension cultures. Through the co-cultivation process, the impacts of gene silencing suppressors on the rAAT production were elucidated, and promising gene silencing suppressors were identified. Furthermore, the combinations of gene silencing suppressors were optimized using design of experiments methodology. The results have shown that in transgenic CMViva cell cultures, the functional rAAT as a percentage of total soluble protein is increased 5.7 fold with the expression of P19, and 17.2 fold with the co-expression of CP, P19 and P24.

Glycoform Modification of Secreted Recombinant Glycoproteins through Kifunensine Addition during Transient Vacuum Agroinfiltration.

Kifunensine, a potent and selective inhibitor of class I α-mannosidases, prevents α-mannosidases I from trimming mannose residues on glycoproteins, thus resulting in oligomannose-type glycans. We report for the first time that through one-time vacuum infiltration of kifunensine in plant tissue, N-linked glycosylation of a recombinant protein transiently produced in whole-plants shifted completely from complex-type to oligomannose-type. Fc-fused capillary morphogenesis protein 2 (CMG2-Fc) containing one N-glycosylation site on the Fc domain, produced in Nicotiana benthamiana whole plants, served as a model protein. The CMG2-Fc fusion protein was produced transiently through vacuum agroinfiltration, with and without kifunensine at a concentration of 5.4 µM in the agroinfiltration suspension. The CMG2-Fc N-glycan profile was determined using LC-MS/MS with a targeted dynamic multiple reaction monitoring (MRM) method. The CMG2-Fc expression level in the infiltrated plant tissue and the percentage of oligomannose-type N-glycans for kifunensine treated plants was 874 mg/kg leaf fresh weight (FW) and 98.2%, respectively, compared to 717 mg/kg leaf FW and 2.3% for untreated plants. Oligomannose glycans are amenable to in vitro enzymatic modification to produce more human-like N-glycan structures that are preferred for the production of HIV-1 viral vaccine and certain monoclonal antibodies. This method allows glycan modifications using a bioprocessing approach without compromising protein yield or modification of the primary sequence, and could be expanded to other small molecule inhibitors of glycan-processing enzymes. For recombinant protein targeted for secretion, kifunensine treatment allows collection of glycoform-modified target protein from apoplast wash fluid (AWF) with minimal plant-specific complex N-glycan at higher starting purity and concentration than in whole-leaf extract, thus simplifying the downstream processing.

Transient Recombinant Protein Production in Glycoengineered Nicotiana benthamiana Cell Suspension Culture.

Transient recombinant protein production is a promising alternative to stable transgenic systems, particularly for emergency situations in which rapid production of novel therapeutics is needed. In plants, Agrobacterium tumefaciens can be used as a gene delivery vector for transient expression. A potential barrier for plant-based production of human therapeutics is that different glycosylation patterns are found on plant and mammalian proteins. Since glycosylation can affect the efficacy, safety and stability of a therapeutic protein, methods to control glycan structures and distributions in plant-based systems would be beneficial. In these studies, we performed Agrobacterium-mediated transient expression in glycoengineered plant cell suspension cultures. To reduce the presence of plant-specific glycans on the product, we generated and characterized cell suspension cultures from β-1,2-xylosyltransferase and α-1,3-fucosyltransferase knockdown Nicotiana benthamiana. An anthrax decoy fusion protein was transiently produced in these glycoengineered plant cell suspension cultures through co-culture with genetically engineered Agrobacterium. The mass ratio of Agrobacterium to plant cells used was shown to impact recombinant protein expression levels. N-glycosylation analysis on the anthrax decoy fusion protein produced in glycoengineered N. benthamiana showed a dramatic reduction in plant-specific N-glycans. Overall, the results presented here demonstrate the feasibility of a simple, rapid and scalable process for transient production of recombinant proteins without plant-specific glycans in a glycoengineered plant cell culture host.

Growth kinetics and scale-up of Agrobacterium tumefaciens.

Production of recombinant proteins in plants through Agrobacterium-mediated transient expression is a promising method of producing human therapeutic proteins, vaccines, and commercial enzymes. This process has been shown to be viable at a large scale and involves growing large quantities of wild-type plants and infiltrating the leaf tissue with a suspension of Agrobacterium tumefaciens bearing the genes of interest. This study examined one of the steps in this process that had not yet been optimized: the scale-up of Agrobacterium production to sufficient volumes for large-scale plant infiltration. Production of Agrobacterium strain C58C1 pTFS40 was scaled up from shake flasks (50-100 mL) to benchtop (5 L) scale with three types of media: Lysogeny broth (LB), yeast extract peptone (YEP) media, and a sucrose-based defined media. The maximum specific growth rate (µ max) of the strain in the three types of media was 0.46 ± 0.04 h-1 in LB media, 0.43 ± 0.03 h-1 in YEP media, and 0.27 ± 0.01 h-1 in defined media. The maximum biomass concentration reached at this scale was 2.0 ± 0.1, 2.8 ± 0.1, and 2.6 ± 0.1 g dry cell weight (DCW)/L for the three media types. Production was successfully scaled up to a 100-L working volume reactor with YEP media, using k L a as the scale-up parameter.

Expression, Purification, and Biophysical Characterization of a Secreted Anthrax Decoy Fusion Protein in Nicotiana benthamiana.

Anthrax toxin receptor-mediated drug development for blocking anthrax toxin action has received much attention in recent decades. In this study, we produced a secreted anthrax decoy fusion protein comprised of a portion of the human capillary morphogenesis gene-2 (CMG2) protein fused via a linker to the fragment crystallizable (Fc) domain of human immunoglobulin G1 in Nicotiana benthamiana plants using a transient expression system. Using the Cauliflower Mosaic Virus (CaMV) 35S promoter and co-expression with the p19 gene silencing suppressor, we were able to achieve a high level of recombinant CMG2-Fc-Apo (rCMG2-Fc-Apo) protein accumulation. Production kinetics were observed up to eight days post-infiltration, and maximum production of 826 mg/kg fresh leaf weight was observed on day six. Protein A affinity chromatography purification of the rCMG2-Fc-Apo protein from whole leaf extract and apoplast wash fluid showed the homodimeric form under non-reducing gel electrophoresis and mass spectrometry analysis confirmed the molecular integrity of the secreted protein. The N-glycosylation pattern of purified rCMG2-Fc-Apo protein was analysed; the major portion of N-glycans consists of complex type structures in both protein samples. The most abundant (>50%) N-glycan structure was GlcNAc2(Xyl)Man3(Fuc)GlcNAc2 in rCMG2-Fc-Apo recovered from whole leaf extract and apoplast wash fluid. High mannose N-glycan structures were not detected in the apoplast wash fluid preparation, which confirmed the protein secretion. Altogether, these findings demonstrate that high-level production of rCMG2-Fc-Apo can be achieved by transient production in Nicotiana benthamiana plants with apoplast targeting.

Bipartite and tripartite Cucumber mosaic virus-based vectors for producing the Acidothermus cellulolyticus endo-1,4-ß-glucanase and other proteins in non-transgenic plants.

BACKGROUND: Using plant viruses to produce desirable proteins in plants allows for using non-transgenic plant hosts and if necessary, the ability to make rapid changes in the virus construct for increased or modified protein product yields. The objective of this work was the development of advanced CMV-based protein production systems to produce Acidothermus cellulolyticus endo-1, 4-ß-glucanase (E1) in non-transgenic plants. RESULTS: We used two new Cucumber mosaic virus (CMV)-based vector systems for producing the green fluorescent protein (GFP) and more importantly, the Acidothermus cellulolyticus endo-1, 4-ß-glucanase (E1) in non-transgenic Nicotiana benthamiana plants. These are the inducible CMVin (CMV-based inducible) and the autonomously replicating CMVar (CMV-based advanced replicating) systems. We modified a binary plasmid containing the complete CMV RNA 3 cDNA to facilitate insertion of desired sequences, and to give modifications of the subgenomic mRNA 4 leader sequence yielding several variants. Quantitative RT-PCR and immunoblot analysis showed good levels of CMV RNA and coat protein accumulation for some variants of both CMVin and CMVar. When genes for E1 or GFP were inserted in place of the CMV coat protein, both were produced in plants as shown by fluorescence (GFP) and immunoblot analysis. Enzymatic activity assays showed that active E1 was produced in plants with yields up to ~ 11 µg/g fresh weight (FW) for specific variant constructs. We also compared in vitro CMV genomic RNA reassortants, and CMV RNA 3 mutants which lacked the C' terminal 33 amino acids of the 3A movement protein in attempts to further increase E1 yield. Taken together specific variant constructs yielded up to ~21 µg/g FW of E1 in non-transgenic plants. CONCLUSIONS: Intact, active E1 was rapidly produced in non-transgenic plants by using agroinfiltration with the CMV-based systems. This reduces the time and cost compared to that required to generate transgenic plants and still gives the comparable yields of active E1. Our modifications described here, including manipulating cloning sites for foreign gene introduction, enhance the ease of use. Also, N. benthamiana, which is particularly suitable for agroinfiltration, is a very good plant for transient protein production.

Technoeconomic Modeling and Simulation for Plant-Based Manufacturing of Recombinant Proteins.

Technoeconomic modeling and simulation is a critical step in defining a manufacturing process for evaluation of commercial viability and to focus experimental process research and development efforts. Technoeconomic analysis (TEA) is increasingly demanded alongside scientific innovation by both public and private funding agencies to maximize efficiency of resource allocation. It is particularly important for plant-based manufacturing, and other nontraditional recombinant protein production platforms, to explicitly demonstrate the manufacturing potential and to identify critical technical and economic challenges through robust technoeconomic analysis. In addition, in silico process modeling and TEA of scaled biomanufacturing facilities allows rapid evaluation of the impacts of process and economic changes on capital expenditures (CAPEX, also sometimes referred to as total capital investment), operational expenditures (OPEX, also known as total manufacturing costs or total production costs), cost of goods sold (COGS, also known as unit production costs), and profitability metrics such as net present value (NPV) and discounted cash flow rate of return (DCROR, also known as internal rate of return or IRR). These models can also be used to assess environmental, health, and safety impact of a designed biomanufacturing facility to evaluate its sustainability and environmental-friendliness. Here we describe a general method for performing technoeconomic modeling and simulation for and environmental assessment of plant-based manufacturing of recombinant proteins.

Plant-based production and characterization of a promising Fc-fusion protein against microgravity-induced bone density loss.

Microgravity-induced bone loss is a main obstacle for long term space missions as it is difficult to maintain bone mass when loading stimuli is reduced. With a typical bone mineral density loss of 1.5% per month of microgravity exposure, the chances for osteoporosis and fractures may endanger astronauts' health. Parathyroid Hormone or PTH (1-34) is an FDA approved treatment for osteoporosis, and may reverse microgravity-induced bone loss. However, PTH proteins requires refrigeration, daily subcutaneous injection, and have a short shelf-life, limiting its use in a resource-limited environment, like space. In this study, PTH was produced in an Fc-fusion form via transient expression in plants, to improve the circulatory half-life which reduces dosing frequency and to simplify purification if needed. Plant-based expression is well-suited for space medicine application given its low resource consumption and short expression timeline. The PTH-Fc accumulation profile in plant was established with a peak expression on day 5 post infiltration of 373 ± 59 mg/kg leaf fresh weight. Once the PTH-Fc was purified, the amino acid sequence and the binding affinity to its target, PTH 1 receptor (PTH1R), was determined utilizing biolayer interferometry (BLI). The binding affinity between PTH-Fc and PTH1R was 2.30 × 10-6 M, similar to the affinity between PTH (1-34) and PTH1R (2.31 × 10-6 M). Its function was also confirmed in a cell-based receptor stimulation assay, where PTH-Fc was able to stimulate the PTH1R producing cyclic adenosine monophosphate (cAMP) with an EC50 of (8.54 ± 0.12) x 10-9 M, comparable to the EC50 from the PTH (1-34) of 1.49 × 10-8 M. These results suggest that plant recombinant PTH-Fc exhibits a similar binding affinity and potency in a PTH1R activation assay compared to PTH. Furthermore, it can be produced rapidly at high levels with minimal resources and reagents, making it ideal for production in low resource environments such as space.