Antioxidant and antithrombotic study of novel chitosan-diallyl disulfide inclusion complexes nanoparticles for hemodialysis applications

Preparation and in vitro evaluation of tissue plasminogen activator-loaded nanoliposomes with anticoagulant coating

The clinical efficacy of tissue plasminogen activator (tPA) is limited by its lack of specific delivery, requiring large therapeutic doses that increase the risk of intracerebral hemorrhage, bleeding at the surgical site, and patient mortality after angioplasty. To address these limitations, this study aimed to develop a chitosan polysulfate (CsPs)-coated liposomal formulation for the sustained release of tPA. The CsPs-coated liposomes containing tPA (Liposome-tPA/CsPs) were fabricated using the thin-film hydration technique and their properties were compared to tPA-encapsulated nanoliposomes without a coating layer (Liposome-tPA). Liposome-tPA/CsPs showed a quasi-spherical morphology with a hydrodynamic diameter of 110 nm, while Liposome-tPA had a diameter of 80 nm. The thermal analysis showed that the degradation temperature and glass transition temperature (Tg) of Liposome-tPA/CsPs were higher than that of tPA alone, indicating improved temperature stability. The in vitro release study demonstrated a slow and sustained release of tPA from the Liposome-tPA/CsPs, with a concentration of 0.02 mg/ml at 1 h and 0.23 mg/ml at 180 h. The CsPs coating layer enhanced the antibacterial and antioxidant activity of the nanoliposomes. Liposome-tPA/CsPs exhibited higher cell viability compared to Liposome-tPA. It also achieved a higher percentage of thrombolysis, with complete clot dissolution observed after 3 h of treatment. These findings suggest that the Liposome-tPA/CsPs can be a promising approach to overcome the limitations associated with the systemic administration of tPA, potentially enhancing its clinical efficacy while reducing the risk of adverse events.

Preparation, Structural Characterization, and Property Investigation of Gallic Acid-Grafted Fungal Chitosan Conjugate

Oxidative stress is the cause of numerous diseases in humans; therefore, there has been a continuous search for novel antioxidant molecules. Fungal chitosan is an attractive molecule that has several applications (antifungal, antibacterial, anticancer and antiparasitic action) owing to its unique characteristics; however, it exhibits low antioxidant activity. The aim of this study was to obtain fungal chitosan (Chit-F) from the fungus Rhizopus arrhizus and synthesize its derivative, fungal chitosan-gallic acid (Chit-FGal), as a novel antioxidant chitosan derivative for biomedical use. A low molecular weight Chi-F (~3.0 kDa) with a degree of deacetylation of 86% was obtained from this fungus. Chit-FGal (3.0 kDa) was synthesized by an efficient free radical-mediated method using hydrogen peroxide (H2O2) and ascorbic acid. Both Chit-F and Chit-FGal showed similar copper chelating activities; however, Chit-FGal was more efficient as an antioxidant, exhibiting twice the total antioxidant capacity than Chi-F (p < 0.05). Furthermore, H2O2 (0.06 M) promoted a 50% decrease in the viabilities of the 3T3 fibroblast cells. However, this effect was abolished in the presence of Chit-FGal (0.05-0.25 mg/mL), indicating that Chit-FGal protected the cells from oxidative damage. These results suggest that Chit-FGal may be a promising agent to combat oxidative stress.