Controlled Delivery of Pan-PAD-Inhibitor Cl-Amidine Using Poly(3-Hydroxybutyrate) Microspheres

Abstract

This study deals with the process of optimization and synthesis of Poly(3-hydroxybutyrate) microspheres with encapsulated Cl-amidine. Cl-amidine is an inhibitor of peptidylarginine deiminases (PADs), a group of calcium-dependent enzymes, which play critical roles in a number of pathologies, including autoimmune and neurodegenerative diseases, as well as cancer. While Cl-amidine application has been assessed in a number of in vitro and in vivo models; methods of controlled release delivery remain to be investigated. P(3HB) microspheres have proven to be an effective delivery system for several compounds applied in antimicrobial, wound healing, cancer, and cardiovascular and regenerative disease models. In the current study, P(3HB) microspheres with encapsulated Cl-amidine were produced in a size ranging from ~4–5 µm and characterized for surface morphology, porosity, hydrophobicity and protein adsorption, in comparison with empty P(3HB) microspheres. Cl-amidine encapsulation in P(3HB) microspheres was optimized, and these were found to be less hydrophobic, compared with the empty microspheres, and subsequently adsorbed a lower amount of protein on their surface. The release kinetics of Cl-amidine from the microspheres were assessed in vitro and expressed as a function of encapsulation efficiency. There was a burst release of ~50% Cl-amidine in the first 24 h and a zero order release from that point up to 16 days, at which time point ~93% of the drug had been released. As Cl-amidine has been associated with anti-cancer effects, the Cl-amidine encapsulated microspheres were assessed for the inhibition of vascular endothelial growth factor (VEGF) expression in the mammalian breast cancer cell line SK-BR-3, including in the presence of the anti-proliferative drug rapamycin. The cytotoxicity of the combinatorial effect of rapamycin with Cl-amidine encapsulated P(3HB) microspheres was found to be 3.5% more effective within a 24 h period. The cells treated with Cl-amidine encapsulated microspheres alone, were found to have 36.5% reduction in VEGF expression when compared with untreated SK-BR-3 cells. This indicates that controlled release of Cl-amidine from P(3HB) microspheres may be effective in anti-cancer treatment, including in synergy with chemotherapeutic agents. Using controlled drug-delivery of Cl-amidine encapsulated in Poly(3-hydroxybutyrate) microspheres may be a promising novel strategy for application in PAD-associated pathologies.

Peptidylarginine Deiminase 3 Modulates Response to Neratinib in HER2 Positive Breast Cancer

“…In addition, the knockdown of PADI3 resulted in restoration of sensitivity to the antiproliferative action of neratinib. Furthermore, combined treatment of neratinib with Cl-amidine, a PADI enzyme inhibitor (43), resensitized the three resistant clones. Together, these data suggest that PADI3 could be a potential therapeutic target in HER2 + breast cancer with neratinib resistance.…”

Role and Therapeutic Targeting Strategies of Neutrophil Extracellular Traps in Inflammation

“…Similar long-term and safe drug release was achieved by poly (3-hydroxybutyrate) microspheres loaded with the Pan-PAD4 inhibitor Cl-amidine. 216 Meanwhile, nanocarrier delivery not only increased stability but also played an incredible role in the curative effect. Free sivelestat is not effective in the mouse model of endotoxic shock; however, interbilayer cross-linked multilayer vesicles incorporating this NE inhibitor prevented the formation of NETs and showed lowered pulmonary inflammation in animals in the context of endotoxic shock.…”

Selective Oxidation of 1,3-Butanediol to 3-Hydroxybutyric Acid over PtSb2 Alloy

“…To decrease the amount of abandoned plastic waste, biobased plastics have been recommended as a promising substitute for petroleum-based plastics because of their biodegradability and/or biocompatibility . Among the commonly reported biobased plastics, polyhydroxyalkanoates (PHAs) are a family of renewable bioplastics that can be synthesized by bacteria and other living microorganisms under nutrient-limited and carbon-rich conditions. , In the literature, PHAs have been used in place of petroleum-based plastics in biomedicine, food, and agriculture industries, and it has been confirmed that PHAs can be completely biodegraded within weeks. − Poly-3-hydroxybutyrate was the first natural PHA product discovered, , and its monomer 3-hydroxybutyric acid (3-HBA) has also been proven to be effective in the treatment of osteoporosis, diabetes mellitus, and neurodegenerative diseases. , …”

“…9−12 Poly-3-hydroxybutyrate was the first natural PHA product discovered, 13,14 and its monomer 3-hydroxybutyric acid (3-HBA) has also been proven to be effective in the treatment of osteoporosis, 15 diabetes mellitus, 16 and neurodegenerative diseases. 17,18 PHAs are currently produced using a single-strain culture technology, which requires a sterile environment and a special purified carbon feedstock. 19 Moreover, it is difficult to synthesize PHAs comprising monomers longer than 14 carbon atoms via microbial fermentation because of the low specificity of the polymerizing enzyme.…”