Publications by authors named "Prakash Manikwar"

Spray drying presents numerous advantages over other drying technologies, particularly for inhaled biologics because of the fine-tuned particle attributes requirements. To fully leverage these benefits, it is crucial to address several process challenges and considerations throughout the end-to-end spray-drying process, including stages prior to, during, and post- drying. This review provides a detailed overview of the challenges associated with spray-drying of biologics along with the aspects of protein degradation.

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To ensure the high quality of biopharmaceutical products, it is imperative to implement specialized unit operations that effectively safeguard the structural integrity of large molecules. While lyophilization has long been a reliable process, spray drying has recently garnered attention for its particle engineering capabilities for the pulmonary route of administration. However, maintaining the integrity of biologics during spray drying remains a challenge.

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Purpose: During biopharmaceutical drug manufacturing, storage, and distribution, proteins in both liquid and solid dosage forms go through various processes that could lead to protein aggregation. The extent of aggregation in the sub-micron range can be measured by analyzing a liquid or post-reconstituted powder sample using Micro-Flow Imaging (MFI) technique. MFI is widely used in biopharmaceutical industries due to its high sensitivity in detecting and analyzing particle size distribution.

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Bispecific antibodies containing single-chain variable fragment (scFv) appended to immunoglobulins G offer unique development challenges. Here, we describe the stability of a novel bispecific format, BiS5, where the scFv is tethered to the C3 domain. BiS5 showed an improved conformational and chemical stability compared with that of BiS4 in which the scFv is appended in the hinge region between the F and F.

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This study describes the physicochemical characterization, stabilization, and formulation design of SM4-AC, an acrylodan-labeled glucose/galactose-binding protein for use in a continuous glucose monitoring device. The physical stability profile of SM4-AC as a function of pH and temperature was monitored using a combination of biophysical techniques and the resulting physical stability profile was visualized using an empirical phase diagram. Forced degradation chemical stability studies (Asn deamidation, Met oxidation) of SM4-AC were performed using a combination of capillary isoelectric focusing, peptide mapping, and reversed-phase HPLC.

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The role of antibody structure (conformation) in solution rheology is probed. It is demonstrated here that pH-dependent changes in the tertiary structure of 2 mAb solutions lead to viscoelasticity and not merely a shear viscosity (η) increase. Steady shear flow curves on mAb solutions are reported over broad pH (3.

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The recombinant hemagglutinin (rHA)-based influenza vaccine Flublok® has recently been approved in the United States as an alternative to the traditional egg-derived flu vaccines. Flublok is a purified vaccine with a hemagglutinin content that is threefold higher than standard inactivated influenza vaccines. When rHA derived from an H3N2 influenza virus was expressed, purified, and stored for 1 month, a rapid loss of in vitro potency (∼50%) was observed as measured by the single radial immunodiffusion (SRID) assay.

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The effects of sucrose and arginine on the conformational and storage stability of an IgG1 monoclonal antibody (mAb) were monitored by differential scanning calorimetry (DSC) and size-exclusion chromatography (SEC), respectively. Excipient effects on protein physical stability were then compared with their effects on the local flexibility of the mAb in solution at pH 6, 25°C using hydrogen/deuterium-exchange mass spectrometry (H/D-MS). Compared with a 0.

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This work examines the effect of three anions from the Hofmeister series (sulfate, chloride, and thiocyanate) on the conformational stability and aggregation rate of an IgG1 monoclonal antibody (mAb) and corresponding changes in the mAb's backbone flexibility (at pH 6 and 25 °C). Compared to a 0.1 M NaCl control, thiocyanate (0.

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The objective of this work is to utilize novel I-domain antigenic-peptide conjugates (IDAC) for targeting antigenic peptides to antigen-presenting cells (APC) to simulate tolerance in experimental autoimmune encephalomyelitis (EAE). IDAC-1 and IDAC-3 molecules are conjugates between the I-domain protein and PLP-Cys and Ac-PLP-Cys-NH(2) peptides, respectively, tethered to N-terminus and Lys residues on the I-domain. The hypothesis is that the I-domain protein binds to ICAM-1 and PLP peptide binds to MHC-II on the surface of APC; this binding event inhibits the formation of the immunological synapse at the APC-T-cell interface to alter T-cell differentiation from inflammatory to regulatory phenotypes.

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The successful implementation of process and product changes for a therapeutic protein drug, both during clinical development and after commercialization, requires a detailed evaluation of their impact on the protein's structure and biological functionality. This analysis is called a comparability exercise and includes a data driven assessment of biochemical equivalence and biological characterization using a cadre of analytical methodologies. This review focuses on describing analytical results and lessons learned from selected published therapeutic protein comparability case studies both for bulk drug substance and final drug product.

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Chromatographic carry-over can severely distort measurements of amide H/D exchange in proteins analyzed by LC/MS. In this work, we explored the origin of carry-over in the online digestion of an IgG1 monoclonal antibody using an immobilized pepsin column under quenched H/D exchange conditions (pH 2.5, 0 °C).

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The objectives of this work are to characterize the identity of I-domain-antigen conjugate (IDAC) and to evaluate the in vivo efficacy of IDAC in suppressing experimental autoimmune encephalomyelitis (EAE) in mouse model. The hypothesis is that the I-domain delivers PLP(139-151) peptides to antigen-presenting cells (APC) and alters the immune system by simultaneously binding to ICAM-1 and MHC-II, blocking immunological synapse formation. IDAC was synthesized by derivatizing the lysine residues with maleimide groups followed by conjugation with PLP-Cys-OH peptide.

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Conjugation of either a fluorescent dye or a drug molecule to the ε-amino groups of lysine residues of proteins has many applications in biology and medicine. However, this type of conjugation produces a heterogeneous population of protein conjugates. Because conjugation of fluorochrome or drug molecule to a protein may have deleterious effects on protein function, the identification of conjugation sites is necessary.

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The long-term objective of this project is to utilize the I-domain protein for the α-subunit of LFA-1 to target drugs to lymphocytes by binding to ICAM receptors on the cell surface. The short-term goal is to provide proof-of-concept that I-domain conjugated to small molecules can still bind to and uptake by ICAM-1 on the surface of lymphocytes (i.e.

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Leukocyte function associated antigen-1 (LFA-1) is a primary cell adhesion molecule of leukocytes required for mediating cellular transmigration into sites of inflammation via the vascular endothelium. A cyclic peptide, cIBR, possesses high affinity for LFA-1, and conjugation to the surface of poly(DL-lactic-co-glycolic acid) nanoparticles can specifically target and deliver the encapsulated agents to T cells expressing LFA-1. The kinetics of targeted nanoparticle uptake by acute lymphoblastic leukemia T cells was investigated by flow cytometry and microscopy and compared to untargeted nanoparticles.

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