A Review on Physicochemical Properties of Polymers Used as Filaments in 3D-Printed Tablets.

Three-dimensional (3D) printing technology has presently been explored widely in the field of pharmaceutical research to produce various conventional as well as novel dosage forms such as tablets, capsules, oral films, pellets, subcutaneous implants, scaffolds, and vaginal rings. The use of this innovative method is a good choice for its advanced technologies and the ability to make tailored medicine specifically for individual patient. There are many 3D printing systems that are used to print tablets, implants, and vaginal rings. Among the available systems, the fused deposition modeling (FDM) is widely utilized. The FDM has been regarded as the best choice of printer as it shows high potential in the production of tablets as a unit dose in 3D printing medicine manufacturing. In order to design a 3D-printed tablet or other dosage forms, the physicochemical properties of polymers play a vital role. One should have proper knowledge about the polymer's properties so that one can select appropriate polymers in order to design 3D-printed dosage form. This review highlighted the various physicochemical properties of polymers that are currently used as filaments in 3D printing. In this manuscript, the authors also discussed various systems that are currently adopted in the 3D printing.

The relationship of metabolic burden to productivity levels in CHO cell lines.

The growing demand for recombinant therapeutics has driven biotechnologists to develop new production strategies. One such strategy for increasing the expression of heterologous proteins has focused on enhancing cell-specific productivity through environmental perturbations. In this work, the effects of hypothermia, hyperosmolarity, high shear stress, and sodium butyrate treatment on growth and productivity were studied using three (low, medium, and high producing) CHO cell lines that differed in their specific productivities of monoclonal antibody. In all three cell lines, the inhibitory effect of these parameters on proliferation was demonstrated. Additionally, compared to the control, specific productivity was enhanced under all conditions and exhibited a consistent cell line specific pattern, with maximum increases (50-290%) in the low producer, and minimum increases (7-20%) in the high producer. Thus, the high-producing cell line was less responsive to environmental perturbations than the low-producing cell line. We hypothesize that this difference is most likely due to the bottleneck associated with a higher metabolic burden caused by higher antibody expression. Increased recombinant mRNA levels and pyruvate carboxylase activities due to low temperature and hyperosmotic stress were found to be positively associated with the metabolic burden.

The relationship between mTOR signalling pathway and recombinant antibody productivity in CHO cell lines.

BACKGROUND: High recombinant protein productivity in mammalian cell lines is often associated with phenotypic changes in protein content, energy metabolism, and cell growth, but the key determinants that regulate productivity are still not clearly understood. The mammalian target of rapamycin (mTOR) signalling pathway has emerged as a central regulator for many cellular processes including cell growth, apoptosis, metabolism, and protein synthesis. This role of this pathway changes in response to diverse environmental cues and allows the upstream proteins that respond directly to extracellular signals (such as nutrient availability, energy status, and physical stresses) to communicate with downstream effectors which, in turn, regulate various essential cellular processes. RESULTS: In this study, we have performed a transcriptomic analysis using a pathway-focused polymerase chain reaction (PCR) array to compare the expression of 84 target genes related to the mTOR signalling in two recombinant CHO cell lines with a 17.4-fold difference in specific monoclonal antibody productivity (qp). Eight differentially expressed genes that exhibited more than a 1.5-fold change were identified. Pik3cd (encoding the Class 1A catalytic subunit of phosphatidylinositol 3-kinase [PI3K]) was the most differentially expressed gene having a 71.3-fold higher level of expression in the high producer cell line than in the low producer. The difference in the gene's transcription levels was confirmed at the protein level by examining expression of p110δ. CONCLUSION: Expression of p110δ correlated with specific productivity (qp) across six different CHO cell lines, with a range of expression levels from 3 to 51 pg/cell/day, suggesting that p110δ may be a key factor in regulating productivity in recombinant cell lines.

Using molecular markers to characterize productivity in Chinese hamster ovary cell lines.

Selection of high producing cell lines to produce maximum product concentration is a challenging and time consuming task for the biopharmaceutical industry. The identification of early markers to predict high productivity will significantly reduce the time required for new cell line development. This study identifies candidate determinants of high productivity by profiling the molecular and morphological characteristics of a panel of six Chinese Hamster Ovary (CHO) stable cell lines with varying recombinant monoclonal antibody productivity levels ranging between 2 and 50 pg/cell/day. We examined the correlation between molecular parameters and specific productivity (qp ) throughout the growth phase of batch cultures. Results were statistically analyzed using Pearson correlation coefficient. Our study revealed that, overall, heavy chain (HC) mRNA had the strongest association with qp followed by light chain (LC) mRNA, HC intracellular polypeptides, and intracellular antibodies. A significant correlation was also obtained between qp and the following molecular markers: growth rate, biomass, endoplasmic reticulum, and LC polypeptides. However, in these cases, the correlation was not observed at all-time points throughout the growth phase. The repeated sampling throughout culture duration had enabled more accurate predictions of productivity in comparison to performing a single-point measurement. Since the correlation varied from day to day during batch cultivation, single-point measurement was of limited use in making a reliable prediction.