Design and Characterization of an Osmotic Pump System for Optimal Feeding and pH Control in Culture to Increase Biomass.

Background: Batch cultures used for various purposes, such as expression screening and recombinant protein production in laboratories, usually have some drawbacks due to the bolus addition of carbon sources, such as glucose and buffers, that lead to overflow metabolism, decreased pH, high osmolality, low biomass yield, and low protein production.

Objectives: This study aimed to overcome the problems of batch culture using the controlled release concept by a controlled porosity osmotic pump (CPOP) system.

Methods: The CPOP was formulated with glucose as a carbon source feeding and sodium carbonate as a pH modifier in the core of the tablet that was coated with a semipermeable membrane containing cellulose acetate and polyethylene glycol (PEG) 400.

PH-sensitive bionanocomposite hydrogel beads based on carboxymethyl cellulose/ZnO nanoparticle as drug carrier.

The present work explains the preparation of new pH-sensitive bionanocomposite beads based on carboxymethyl cellulose (CMC) and ZnO nanoparticles for use as controlled release drug delivery systems. Fe ion as physical crosslinking agent was used to prepare ionic cross-linked bionanocomposite hydrogel beads. Propranolol hydrochloride (PPN) has been chosen as a model drug.