Preparation of Drug Sustained-Release Scaffold with De-Epithelized Human Amniotic Epithelial Cells and Thiolated Chitosan Nanocarriers and Its Repair Effect on Spinal Cord Injury

The disability rate of spinal cord injury (SCI) is extremely high, and stem cell inhibition is one of the most effective schemes in treating the spinal cord, but the survival rate is extremely low after stem cell transplantation, so it cannot be widely used in clinic. Studies have revealed that loading stem cells with biological scaffolds can effectively improve the survival rate and effect after stem cell transplantation. Therefore, this research was devised to analyze the repair effect of thiolated chitosan nanocarriers scaffold carrying de-epithelized human amniotic epithelial cells (HAECs) on SCI. And we used thiolated chitosan as nanocarriers, aiming to provide a reliable theoretical basis for future clinical practice. Through experiments, we concluded that the Tarlov and BBB scores of rats with SCI were raised under the intervention of thiolated chitosan carrying HAECs, while the inflammatory factors in serum, oxidative stress reaction in spinal cord tissue, apoptosis rate of nerve cells, and autophagy protein expression were all suppressed. Thus, the thiolated chitosan carrying HAECs may be applied to treat SCI by suppressing autophagy protein expression, oxidative stress response, and release of inflammatory factors in spinal cord tissue, which may be a new clinical therapy for SCI in the future. Even though we cannot understand exactly the therapeutic mechanism of thiolated chitosan carrying HAECs for SCI, the real clinical application of thiolated chitosan carrying HAECs needs to be confirmed by human experiments.

Fabrication of Tizanidine Loaded Patches Using Flaxseed Oil and Coriander Oil as a Penetration Enhancer for Transdermal Delivery

Transdermal drug delivery is important to maintain plasma drug concentrations for therapeutic efficacy. The current study reports the design, formulation, and evaluation of tizanidine transdermal patches formulated using chitosan and thiolated chitosan, ethyl cellulose (EC), polyvinylpyrrolidone (PVP), and Eudragit RL100 in different ratios. The tizanidine patches were formulated using flaxseed oil and coriander oil in the concentrations of 1% v/w, 2% v/w, 3% v/w, 4% v/w, 5% v/w, and 10% v/w. The patches were subjected to characterization of physicochemical property (thickness, weight uniformity, drug content, efficiency, percentage moisture uptake/loss), in vitro drug release and drug permeation, skin irritation, in vivo application, pharmacokinetics analysis, and stability studies. The results indicate that the interaction of thiolated chitosan with the negative charges of the skin opens the tight junctions of the skin, whereas flaxseed and coriander oils change the conformational domain of the skin. The novelty of this study is in the use of flaxseed and coriander oils as skin permeation enhancers for the formulation of tizanidine transdermal patches. The formulations follow non-Fickian drug release kinetics. The FTZNE23, FTZNE36 and FTZNE54, with 5% v/w flaxseed oil loaded formulations, exhibited higher flux through rabbit skin compared with FTZNE30, FTZNE35, FTZNE42, and FTZNE47, formulations loaded with 10% v/w coriander oil. The study concludes that flaxseed oil is a better choice for formulating tizanidine patches, offering optimal plasma concentration and therapeutic efficacy, and recommends the use of flaxseed and coriander oil based patches as a novel transdermal delivery system for tizanidine and related classes of drugs.

Anti-Foulant Ultrafiltration Polymer Composite Membranes Incorporated with Composite Activated Carbon/Chitosan and Activated Carbon/Thiolated Chitosan with Enhanced Hydrophilicity

A rapid increase in population worldwide is giving rise to the severe problem of safe drinking water availability, necessitating the search for solutions that are effective and economical. For this purpose, membrane technology has shown a lot of promise but faces the challenge of fouling, leading to a reduction in its lifetime. In this study, ultrafiltration polyethersulfone membranes were synthesized in two different concentrations, 16% wt. and 20% wt., using the phase inversion method. Chitosan and activated carbon were incorporated as individual fillers and then as composites in both the concentrations. A novel thiolated chitosan/activated carbon composite was introduced into a polyethersulfone membrane matrix. The membranes were then analyzed using Attenuated Total Reflection–Fourier-Transform Infrared spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), optical profilometry, gravimetric analysis, water retention, mechanical testing and contact angle. For membranes with the novel thiolated chitosan/activated carbon composite, Scanning Electron Microscopy micrographs showed better channels, indicating a better permeability possibility, reiterated by the flux rate results. The flux rate and bovine serum albumin flux were also assessed, and the results showed an increase from 105 L/m2h to 114 L/m2h for water flux and the antifouling determined by bovine serum albumin flux increased from 23 L/m2h to 51 L/m2h. The increase in values of water uptake from 22.84% to 76.5% and decrease in contact angle from 64.5 to 55.7 showed a significant increase in the hydrophilic character of the membrane.