Effects of Glutathione on Hydrolytic Enzyme Activity in the Mouse Hepatocytes

Activity of Lysosomal Enzymes During Protein Malnutrition and Progesterone Supplementation in the Mouse

This study investigated the effects of protein malnutrition and progesterone supplementation on the activities of a spectrum of lysosomal enzymes in tissue fragments of mouse liver and kidney. The working hypothesis was that the known anti-stress action of progesterone could have to do with the inhibition of lysosomes which are engaged in apoptotic and oxidative stress-induced responses. The study investigated the effects of exogenous progesterone in chronically (3 weeks) protein-malnourished (10% protein) mice on the activities of lysosomal hydrolases in liver and kidney tissues. Progesterone was injected intraperitoneally in a dose of 2 μg/g body mass dissolved in a vehicle volume of 10 μL/g body mass during the final 3 days of exposure to either low 10% or standard 16% protein content in the chow. After euthanizing the animals, tissue fragments of liver and kidney assayed for the content of lysosomal enzymes. The results demonstrated the stimulating effect of protein malnutrition on lysosomal activities. We further found, contrary to our hypothesis, that progesterone supplementation during both standard and low-protein conditions enhanced lysosomal activities, particularly acting in concert with protein malnutrition in kidney tissue. The effects were selective concerning both lysosomal enzymes and tissues and of highly variable magnitude. Nonetheless, we believe we have shown that progesterone assists protein malnutrition in stimulation of lysosomal enzymes, which suggests the possibility of the hormone's engagement in cleansing the cellular milieu in disorders consisting of accumulation of toxic molecules.

Recent Advances in Degradable Hybrids of Biomolecules and NGs for Targeted Delivery

Recently, the fast development of hybrid nanogels dedicated to various applications has been seen. In this context, nanogels incorporating biomolecules into their nanonetworks are promising innovative carriers that gain great potential in biomedical applications. Hybrid nanogels containing various types of biomolecules are exclusively designed for: improved and controlled release of drugs, targeted delivery, improvement of biocompatibility, and overcoming of immunological response and cell self-defense. This review provides recent advances in this rapidly developing field and concentrates on: (1) the key physical consequences of using hybrid nanogels and introduction of biomolecules; (2) the construction and functionalization of degradable hybrid nanogels; (3) the advantages of hybrid nanogels in controlled and targeted delivery; and (4) the analysis of the specificity of drug release mechanisms in hybrid nanogels. The limitations and future directions of hybrid nanogels in targeted specific- and real-time delivery are also discussed.

Switchable conformational changes of DNA nanogel shells containing disulfide–DNA hybrids for controlled drug release and efficient anticancer action

Oligonucleotide strands containing dithiol (–SS–) groups were used as the co-crosslinkers in PNIPA–AAc based nanogels (NGs). They hybridized with PEG–oligonucleotides introduced into the gels. The specific DNA hybrid formed in the nanogel/nanocarrier was involved in highly efficient accumulation of intercalators. The presence of –SS– groups/bridges improved the storing efficiency of doxorubicin (Dox) in DNA hybrids by 53, 40 and 20% compared to regular, single stranded and regular double stranded DNA crosslinkers, respectively. The explicit arrangement of the hybrids in the carrier enabled their reduction by glutathione and an effective cancer treatment while the side toxicity could be reduced. Compared to the NGs with traditional crosslinkers and those containing typical dsDNA-based hybrids, an improved, switchable and controlled drug release occurred in the novel NGs. Since the novel NGs can release the oligonucleotide strands during their degradation, this gives an opportunity for a combined drug-gene therapy.

Switchable conformational changes of multiresponsive nanogels containing disulfide/DNA hybrid shells for pulsative drug release.