Formulation and optimization of pH-sensitive nanocrystals for improved oral delivery.

The challenge of low water solubility in pharmaceutical science profoundly impacts drug absorption and therapeutic effectiveness. Nanocrystals (NC), consisting of drug molecules and stabilizing agents, offer a promising solution to enhance solubility and control release rates. In the pharmaceutical industry, top-down techniques are favored for their flexibility and cost-effectiveness. However, increased solubility can lead to premature drug dissolution in the stomach, which is problematic due to the acidic pH or enzymes. Researchers are exploring encapsulating agents that facilitate drug release at customized pH levels as a valuable strategy to address this. This study employed wet milling and spray drying techniques to create encapsulated NC for delivering the drug to the intestinal tract using the model drug ivermectin (IVM). Nanosuspensions (NS) were efficiently produced within 2 h using NanoDisp®, with a particle size of 198.4 ± 0.6 nm and a low polydispersity index (PDI) of 0.184, ensuring uniformity. Stability tests over 100 days at 4 °C and 25 °C demonstrated practical viability, with no precipitation or significant changes observed. Cytotoxicity evaluations indicated less harm to Caco-2 cells compared to the pure drug. Furthermore, the solubility of the NC increased by 47-fold in water and 4.8-fold in simulated intestinal fluid compared to the pure active compound. Finally, dissolution tests showed less than 10% release in acidic conditions and significant improvement in simulated intestinal conditions, promising enhanced drug solubility and bioavailability. This addresses a long-standing pharmaceutical challenge in a cost-effective and scalable manner.

Perinatal Protein Restriction Impacts Nuclear O-GalNAc Glycosylation in Cells of Liver and Brain Structures of the Rat.

BACKGROUND: Post-translational modifications are key factors in the modulation of nuclear protein functions controlling cell physiology and an individual's health. OBJECTIVES: This study examined the influence of protein restriction during the perinatal period on the nuclear O-N-acetylgalactosamine (O-GalNAc) glycosylation of cells from the liver and parts of the brain in the rat. METHODS: Pregnant Wistar rats were divided into 2 groups on day 14 of pregnancy and fed ad libitum 1 of 2 isocaloric diets containing 24% (well-fed) or 8% (protein-restricted diet) casein until the end of the experiment. Male pups were studied after weaning at 30 d of life. Animals and their organ/tissues (liver, cerebral cortex, cerebellum and hippocampus) were weighed. Cell nuclei were purified, and the presence in nucleus and cytoplasm of all factors required for the initiation of O-GalNAc glycan biosynthesis, i.e., the sugar donor (UDP-GalNAc), enzyme activity (ppGalNAc-transferase) and the glycosylation product (O-GalNAc glycans), were evaluated by western blotting, fluorescent microscopy, enzyme activity, enzyme-lectin sorbent assay and mass spectrometry. RESULTS: The perinatal protein deficit reduced progeny weight, as well as the cerebral cortex and cerebellum weight. UDP-GalNAc levels in the cytoplasm and nuclei of the liver, the cerebral cortex, cerebellum, or hippocampus were not affected by the perinatal dietary protein deficits. However, this deficiency affected the ppGalNAc-transferase activity localized in the cerebral cortex and hippocampus cytoplasm as well as in the liver nucleus, thus reducing the "writing" ppGalNAc-transferase activity of O-GalNAc glycans. In addition, liver nucleoplasm from protein-restricted offspring revealed a significant reduction in the expression of O-GalNAc glycans on important nuclear proteins. CONCLUSIONS: Our results report an association between the consumption of a protein-restricted diet by the dam and her progeny with the modulation in the offspring' liver nuclei O-GalNAc glycosylation, which may ultimately regulate nuclear protein functions.

Polypeptide N-acetylgalactosamine transferase 3: a post-translational writer on human health.

Polypeptide N-acetylgalactosamine transferase 3 (ppGalNAc-T3) is an enzyme involved in the initiation of O-GalNAc glycan biosynthesis. Acting as a writer of frequent post-translational modification (PTM) on human proteins, ppGalNAc-T3 has key functions in the homeostasis of human cells and tissues. We review the relevant roles of this molecule in the biosynthesis of O-GalNAc glycans, as well as in biological functions related to human physiological and pathological conditions. With main emphasis in ppGalNAc-T3, we draw attention to the different ways involved in the modulation of ppGalNAc-Ts enzymatic activity. In addition, we take notice on recent reports of ppGalNAc-T3 having different subcellular localizations, highlight critical intrinsic and extrinsic functions in cellular physiology that are exerted by ppGalNAc-T3-synthesized PTMs, and provide an update on several human pathologies associated with dysfunctional ppGalNAc-T3. Finally, we propose biotechnological tools as new therapeutic options for the treatment of pathologies related to altered ppGalNAc-T3. KEY MESSAGES: ppGalNAc-T3 is a key enzyme in the human O-GalNAc glycans biosynthesis. enzyme activity is regulated by PTMs, lectin domain and protein-protein interactions. ppGalNAc-T3 is located in human Golgi apparatus and cell nucleus. ppGalNAc-T3 has a central role in cell physiology as well as in several pathologies. Biotechnological tools for pathological management are proposed.

Most of anti-glycolipid IgG-antibodies associated to neurological disorders occur without their IgM counterpart.

BACKGROUND: Different neurological disorders frequently display antibodies against several self-glycans. Increasing evidence supports their pathogenic role; however, far less is known about their origin. Meanwhile, antibodies recognizing non-self glycans appear in normal human serum during immune response to bacteria. METHODS: Using high performance thin layer chromatography-immunostaining, we comparatively evaluated humoral immune response (IgG and IgM immunoreactivity) against glycolipids carrying self-glycans (GM3/GM2/GM1/GD1a/GD1b/GD3/GT1b/GQ1b) and non-self glycans (Forssman/GA1/"A" blood group/Nt7) in sera from 383 patients with neurological disorders along with 87 healthy controls. RESULTS: In contrast to no healthy controls having anti-self glycan IgG antibodies, one-fifth of patients' sera had anti-self glycan IgG antibodies: remarkably, 60% of these occurred without IgM antibodies of the same specificity. Contrary to this unusual fact (anti-self glycan IgG occurrence without simultaneous presence of IgM having the same specificity ~ IgG/IgM discordance), all IgG antibodies against non-self glycans occurred simultaneously with their IgM antibody counterpart (i.e. 0% discordance). When analyzed closer, the IgG/IgM discordance frequency for anti-self glycans exhibited a dual trend: below 40% for IgG antibodies against GM2, GM1 and GD1b, and greater than 53% for IgG antibodies against the remaining self glycans. Interestingly, this discordance behavior was common to several different neurological disorders. CONCLUSIONS: Classic immunology principles indicate this anti-self glycan IgG/IgM discordance should not occur in an antibody response; its unusual presence is discussed within the "binding site drift hypothesis" context, where anti-self glycan IgG antibodies could originate from pre-existing IgG recognizing structurally-related non-self glycans.