Longitudinal Study on the Antimicrobial Performance of a Polyhexamethylene Biguanide (PHMB)-Treated Textile Fabric in a Hospital Environment.

Healthcare workers in the hospital environment are at risk of infection and body fluids such as saliva, bacterial contamination, oral bacteria, etc. directly or indirectly exacerbate this issue. These bio-contaminants, when adhered to hospital linens and clothing, grow substantially, as conventional textile products provide a favorable medium for bacterial and viral growth, adding to the risk of transmitting infectious diseases in the hospital environment. Textiles with durable antimicrobial properties prevent microbial colonization on their surfaces and help contain the spread of pathogens. This longitudinal study aimed to investigate the antimicrobial performance of PHMB-treated healthcare uniforms during prolonged usage and repetitive laundry cycles in a hospital environment. The PHMB-treated healthcare uniforms displayed non-specific antimicrobial properties and remained efficient (>99% against S. aureus and K. pneumoniae) after use for 5 months. With the fact that no antimicrobial resistance was reported towards PHMB, the presented PHMB-treated uniform may reduce infection in hospital settings by minimizing the acquisition, retention, and transmission of infectious diseases on textile products.

A novel control scheme for inducing angiostatin-human IgG fusion protein production using recombinant CHO cells in a oscillating bioreactor.

In this study, a novel control scheme for inducing protein production using a recombinant CHO cell line in a BelloCell bioreactor was developed. This control scheme was applied in a simple regular semi-batch process. Production of angiostatin-human IgG fusion protein in a suspension recombinant CHO cell culture and a protein-free medium was used for this study. The bottom holding time (BH) was the sole operating variable to control the exposure time of the cells immobilized on the carriers to the air and allow the nutrient remained on the liquid film of the carriers to be consumed to a threshold level so that the cells can be arrested and promoted for protein production. In the cell cultures with various BH (1.5-90 min), final cell densities of 1.6-4.0 x 10(9) have been obtained in 20 days while total angiostatin-human IgG production of 228-388 mg have been harvested. In general, low BH will minimize the nutrient limitation and favor the cell growth, while high BH will restrict the nutrient and promote the production in this type of non-growth associated production systems. It was found that specific production rate was generally inversely proportional to the specific growth rate. In this case of study, BH of 30 and 60 min were found to be about 72% better than BH of 1.5 min and 35% better than BH of 9 and 90 min in term of the total angiostatin-human IgG production. In comparison to a conventional spinner flask study, a 3.8-fold increase of the total angiostatin-human IgG production was realized in a 35-day culture. This study illustrated that a simple method of using BH in a semi-batch process can effectively control the apparent nutrient concentration to the cells, and thus regulate the cell growth and protein production in a novel oscillating bioreactor.

Cultivation of HEK 293 cell line and production of a member of the superfamily of G-protein coupled receptors for drug discovery applications using a highly efficient novel bioreactor.

A process of producing a receptor in HEK-293 cells used for the drug discovery program at Pfizer Inc. has been successfully developed with a novel BelloCell bioreactor to replace the conventional 2-D cell culturing devices including Cell Factories and roller bottles. A single BelloCell-500 has produced >1.4 x 10(9) HEK-293 cells, which are equivalent to those produced by 12 roller bottles, with substantially easier operation, single inoculation, less inoculum, less medium consumption and better space utilization. The receptor expression levels are better than those obtained by the traditional process. 3.7 pmoles of radioligandY mg(-1) protein were attained in the bioreactor compared to 2.3 pmoles of radioligandY mg(-1) protein in roller bottles. This may be attributed to the three dimensional attachment during cell growth. A 92% cell recovery from the bioreactor has been attained using Acutase or Trypsin treatment followed by four washes. It has been proven to be a viable and efficient device to produce adherent cells and express target components of interest for drug discovery applications.