@article{lavoie_rojas_khan_shim_2024, title={Charge Protection in Electret Air Filtration Nonwoven Materials}, volume={4}, ISSN={["2365-709X"]}, url={https://doi.org/10.1002/admt.202301670}, DOI={10.1002/admt.202301670}, abstractNote={AbstractNonwoven media used as electret air filters are often embedded with charges to improve particle capture efficiency. These charged filters are invariably exposed to low surface tension fluids such as oils and alcohols leading to charge loss. In this study, filtration media are endowed with charge protection through increased surface repellency using melt additives that can migrate to the surface during processing. Nonwovens containing fluorochemical melt additives are produced, and examined to determine the relationship between surface chemistry, isopropyl alcohol (IPA) repellency, resultant charge retention, and filtration characteristics. Surface fluorine/carbon (F/C) ratios of ≈0.2 are sufficient to protect filtration performance from vapor discharging methods. Samples with bulk additive loadings of 1.2% or higher are found to achieve the necessary repellency to resist discharging independent of the migration state of the sample, while samples loaded at the 0.6% level required sufficient migration to achieve the requisite F/C ratio of 0.2 in order to be protected. Samples that achieved the necessary surface chemistry to provide significant IPA repellency retained > 80% of electret charge and corresponding filtration performance. These results have special significance in the design of filtration media relevant in global healthcare and other industrial settings.}, journal={ADVANCED MATERIALS TECHNOLOGIES}, author={Lavoie, Joseph and Rojas, Orlando J. and Khan, Saad A. and Shim, Eunkyoung}, year={2024}, month={Apr} }
 @article{pham_linova_smith_brown_elhanafi_fan_lavoie_woodley_carbonell_2024, title={Novel multimodal cation-exchange membrane for the purification of a single-chain variable fragment from Pichia pastoris supernatant}, volume={1718}, ISSN={["1873-3778"]}, DOI={10.1016/j.chroma.2024.464682}, abstractNote={A novel salt-tolerant cation-exchange membrane, prepared with a multimodal ligand, 2-mercaptopyridine-3-carboxylic acid (MMC-MPCA), was examined for its purification properties in a bind-and-elute mode from the high conductivity supernatant of a Pichia pastoris fermentation producing and secreting a single-chain variable fragment (scFv). If successful, this approach would eliminate the need for a buffer exchange prior to product capture by ion-exchange. Two fed-batch fermentations of Pichia pastoris resulted in fermentation supernatants reaching an scFv titer of 395.0 mg/L and 555.7 mg/L, both with a purity of approximately 83%. The MMC-MPCA membrane performance was characterized in terms of pH, residence time (RT), scFv load, and scFv concentration to identify the resulting dynamic binding capacity (DBC), yield, and purity achieved under optimal conditions. The MMC-MPCA membrane exhibited the highest DBC of 39.06 mg/mL at pH 5.5, with a residence time of 1 minute, while reducing the pH below 5.0 resulted in a significant decrease of the DBC to around 2.5 mg/mL. With almost no diffusional limitations, reducing the RT from 2 to 0.2 min did not negatively impact the DBC of the MMC-MPCA membrane, resulting in a significant improvement in productivity of up to 180 mg/mL/min at 0.2 min RT. Membrane fouling was observed when reusing the membranes at 0.2 and 0.5 min RT, likely due to the enhanced adsorption of impurities on the membrane. Changing the amount of scFv loaded onto the membrane column did not show any changes in yield, instead a 10-20% loss of scFv was observed, which suggested that some of the produced scFv were fragmented or had aggregated. When performing the purification under the optimized conditions, the resulting purity of the product improved from 83% to approximately 92-95%.}, journal={JOURNAL OF CHROMATOGRAPHY A}, author={Pham, Dan N. and Linova, Marina Y. and Smith, William K. and Brown, Hunter and Elhanafi, Driss and Fan, Jinxin and Lavoie, Joseph and Woodley, John M. and Carbonell, Ruben G.}, year={2024}, month={Mar} }
 @article{kilgore_moore_sripada_chu_shastry_barbieri_hu_tian_petersen_mohammadifar_et al._2024, title={Peptide ligands for the universal purification of exosomes by affinity chromatography}, volume={8}, ISSN={["1097-0290"]}, DOI={10.1002/bit.28821}, abstractNote={Abstract Exosomes are gaining prominence as vectors for drug delivery, vaccination, and regenerative medicine. Owing to their surface biochemistry, which reflects the parent cell membrane, these nanoscale biologics feature low immunogenicity, tunable tissue tropism, and the ability to carry a variety of payloads across biological barriers. The heterogeneity of exosomes' size and composition, however, makes their purification challenging. Traditional techniques, like ultracentrifugation and filtration, afford low product yield and purity, and jeopardizes particle integrity. Affinity chromatography represents an excellent avenue for exosome purification. Yet, current affinity media rely on antibody ligands whose selectivity grants high product purity, but mandates the customization of adsorbents for exosomes with different surface biochemistry while their binding strength imposes elution conditions that may harm product's activity. Addressing these issues, this study introduces the first peptide affinity ligands for the universal purification of exosomes from recombinant feedstocks. The peptides were designed to (1) possess promiscuous biorecognition of exosome markers, without binding process‐related contaminants and (2) elute the product under conditions that safeguard product stability. Selected ligands SNGFKKHI and TAHFKKKH demonstrated the ability to capture of exosomes secreted by 14 cell sources and purified exosomes derived from HEK293, PC3, MM1, U87, and COLO1 cells with yields of up to 80% and up‐to 50‐fold reduction of host cell proteins (HCPs) upon eluting with pH gradient from 7.4 to 10.5, recommended for exosome stability. SNGFKKHI‐Toyopearl resin was finally employed in a two‐step purification process to isolate exosomes from HEK293 cell fluids, affording a yield of 68% and reducing the titer of HCPs to 68 ng/mL. The biomolecular and morphological features of the isolated exosomes were confirmed by analytical chromatography, Western blot analysis, transmission electron microscopy, nanoparticle tracking analysis.}, journal={BIOTECHNOLOGY AND BIOENGINEERING}, author={Kilgore, Ryan E. and Moore, Brandyn D. and Sripada, Sobhana A. and Chu, Wenning and Shastry, Shriarjun and Barbieri, Eduardo and Hu, Shiqi and Tian, Weihua and Petersen, Heidi and Mohammadifar, Mohammad and et al.}, year={2024}, month={Aug} }
 @article{lavoie_fan_pourdeyhimi_boi_carbonell_2023, title={Advances in high-throughput, high-capacity nonwoven membranes for chromatography in downstream processing: A review}, volume={5}, ISSN={["1097-0290"]}, url={https://doi.org/10.1002/bit.28457}, DOI={10.1002/bit.28457}, abstractNote={AbstractNonwoven membranes are highly engineered fibrous materials that can be manufactured on a large scale from a wide range of different polymers, and their surfaces can be modified using a large variety of different chemistries and ligands. The fiber diameters, surface areas, pore sizes, total porosities, and thicknesses of the nonwoven mats can be carefully controlled, providing many opportunities for creative approaches for the development of novel membranes with unique properties to meet the needs of the future of downstream processing. Fibrous membranes are already finding use in ultrafiltration, microfiltration, depth filtration, and, more recently, in membrane chromatography for product capture and impurity removal. This article summarizes the various methods of manufacturing nonwoven fabrics, and the many methods available for the modification of the fiber surfaces. It also reviews recent studies focused on the use of nonwoven fabric devices in membrane chromatography and provides some perspectives on the challenges that need to be overcome to increase binding capacities, decrease residence times, and reduce pressure drops so that eventually they can replace resin column chromatography in downstream process operations.}, journal={BIOTECHNOLOGY AND BIOENGINEERING}, author={Lavoie, Joseph and Fan, Jinxin and Pourdeyhimi, Behnam and Boi, Cristiana and Carbonell, Ruben G.}, year={2023}, month={May} }
 @article{fan_boi_lemma_lavoie_carbonell_2021, title={Iminodiacetic Acid (IDA) Cation-Exchange Nonwoven Membranes for Efficient Capture of Antibodies and Antibody Fragments}, volume={11}, ISSN={2077-0375}, url={http://dx.doi.org/10.3390/membranes11070530}, DOI={10.3390/membranes11070530}, abstractNote={There is strong need to reduce the manufacturing costs and increase the downstream purification efficiency of high-value therapeutic monoclonal antibodies (mAbs). This paper explores the performance of a weak cation-exchange membrane based on the coupling of IDA to poly(butylene terephthalate) (PBT) nonwoven fabrics. Uniform and conformal layers of poly(glycidyl methacrylate) (GMA) were first grafted to the surface of the nonwovens. Then IDA was coupled to the polyGMA layers under optimized conditions, resulting in membranes with very high permeability and binding capacity. This resulted in IgG dynamic binding capacities at very short residence times (0.1–2.0 min) that are much higher than those achieved by the best cation-exchange resins. Similar results were obtained in the purification of a single-chain (scFv) antibody fragment. As is customary with membrane systems, the dynamic binding capacities did not change significantly over a wide range of residence times. Finally, the excellent separation efficiency and potential reusability of the membrane were confirmed by five consecutive cycles of mAb capture from its cell culture harvest. The present work provides significant evidence that this weak cation-exchange nonwoven fabric platform might be a suitable alternative to packed resin chromatography for low-cost, higher productivity manufacturing of therapeutic mAbs and antibody fragments.}, number={7}, journal={Membranes}, publisher={MDPI AG}, author={Fan, Jinxin and Boi, Cristiana and Lemma, Solomon Mengistu and Lavoie, Joseph and Carbonell, Ruben G.}, year={2021}, month={Jul}, pages={530} }
 @article{lavoie_chu_lavoie_hetzler_williams_carbonell_menegatti_2021, title={Removal of host cell proteins from cell culture fluids by weak partitioning chromatography using peptide-based adsorbents}, volume={257}, ISSN={["1873-3794"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85093930679&partnerID=MN8TOARS}, DOI={10.1016/j.seppur.2020.117890}, abstractNote={This work presents the removal of host cell proteins (HCPs) from a Chinese Hamster Ovary clarified cell culture fluid (CHO CCCF) containing a therapeutic monoclonal antibody (mAb) by weak partitioning chromatography (WPC). The chromatographic adsorbents were produced by functionalizing Toyopearl resin with HCP-binding tetrameric multipolar (4MP) or hexameric hydrophobic/cationic (6HP) peptides. The CCCF was loaded on columns packed with either 4MP-Toyopearl or 6HP-Toyopearl resin only, or a 4MP and 6HP resin mixture at different values of residence time (RT: 0.5, 1, 2, and 5 min). The temporal profiles of concentration of HCPs and mAb in the effluents confirmed the binding mechanism by WPC, where both HCPs and mAb are initially bound by the peptide ligands, but, as more CCCF is fed to the column, the incoming HCPs displace the bound mAbs. In particular, 4MP was shown to capture more selectively high molecular weight HCPs, while 6HP was more effective in binding low molecular weight HCPs. Under optimal loading conditions (~60–80 g of proteins per L of adsorbent; RT of 5 min), the 6HP+4MP-Toyopearl adsorbent provided mAb yield and purity of >80% and up to 90%, respectively. Conversely, the control resin Toyopearl SuperQ-650 M resulted in 70% yield and 75% purity under the same conditions. Proteomic analysis of the effluents demonstrated that 6HP+4MP-Toyopearl adsorbent removes HCPs known for their immunogenicity or IgG co-elution or degradation, demonstrating the potential of these peptide-based resins as HCP scrubbers in mAb purification processes.}, journal={SEPARATION AND PURIFICATION TECHNOLOGY}, author={Lavoie, R. Ashton and Chu, Wenning and Lavoie, Joseph H. and Hetzler, Zachary and Williams, Taufika Islam and Carbonell, Ruben and Menegatti, Stefano}, year={2021}, month={Feb} }