Trends in Peptide and Protein Sciences

Chinese hamster ovary (CHO) cells are extremely vulnerable to cell viability loss in culture despite the availability of different nutrients supplementation strategies. As a result, extending the culture lifetime can profoundly increase recombinant protein expression. Overexpression of HSP27 and its anti-apoptotic effects have been shown in human cell lines in previous studies. In the current study, mouse HSP27 (mHSP27) was cloned in pcDNA 3.1 hygro expression vector and was expressed in CHO-K1 cells to assess its impacts on cell viability and growth. Expression of mHSP27 in CHO-K1 cells was confirmed using RT-PCR. A 3-fold enhancement in peak viable cell density of mHSP27 transfected clones was observed, and culture viability loss was delayed by 2 days compared to un-transfected cells. In future studies, the resulting mHSP27 CHO-K1 cells could be employed as a novel host system for the transient and stable expression of therapeutic recombinant proteins.

HIGHLIGHTS

• Cell engineering is an effective strategy to cope with apoptosis in CHO cells.


• HSP27 is involved in mammalian cell apoptosis.


• Expression of the mouse HSP27 increased the viability and cell density of CHO-K1 cells.

Crocin, the main active constituent of saffron, has many important biological activities. Due to its anti-inflammatory properties, crocin can be potentially effective in different pathological conditions including oral ulcers. Novel drug delivery systems such as hydrogels have been used to increase the stability of crocin and provide a controlled release of this compound. Casein is the main protein of milk that possesses suitable properties for the fabrication of hydrogels. In this paper, casein-based hydrogels with different casein to crocin weight ratios were synthesized using the acid-gelation method. The prepared crocin-loaded hydrogels were characterized regarding their rheological behavior, drug content, swelling ratio, surface morphology, thermal stability, and in vitro release profile. The structure of casein hydrogels was characterized using Fourier transform infrared and X-ray diffraction. All formulations exhibited a pseudoplastic rheological behavior and there was no statistically significant difference in viscosity among them. Hydrogel with casein to crocin weight ratio of 10:1 had larger pores and demonstrated a higher swelling percentage and suitable thermal stability. All casein-based hydrogels demonstrated a slow release of crocin over 24 hours and the hydrogel with lower casein to crocin weight ratio had an increased release rate. Taken together, casein-based hydrogels were found to be effective carriers to provide a controlled release system for crocin delivery.

HIGHLIGHTS

• Casein-based hydrogels were developed for delivery of crocin.


• Casein-based hydrogels provided a controlled in vitro release profile for crocin.


• Hydrogel with a lower casein ratio exhibited a higher release rate of crocin.

HIGHLIGHTS

• Rapid spread of Omicron variant is a serious challenge.


• More than 50 mutations have occurred in Omicron variant.


• The mutations have caused the RBD structure to undergo significant changes