Mucoadhesive Dendrons Conjugated to Mesoporous Silica Nanoparticles as a Drug Delivery Approach for Orally Administered Biopharmaceuticals

Tailored Polymersomes for Enhanced Oral Drug Delivery: pH-Sensitive Systems for Intestinal Delivery of Immunosuppressants

Ensuring precise drug release at target sites is crucial for effective treatment. Here, pH-responsive nanoparticles for oral administration of mycophenolate mofetil, an alternative therapy for patients with inflammatory bowel disease unresponsive to conventional treatments is developed. However, its oral administration presents challenges due to its low solubility in the small intestine and high solubility and absorption in the stomach. Therefore, this aim is to design a drug delivery system capable of maintaining drug solubility compared to the free drug while delaying absorption from the stomach to the intestine. Successful synthesis and assembly of a block copolymer incorporating a pH-responsive functional group is achieved. Dynamic light scattering indicated a significant change in hydrodynamic size when the pH exceeded 6.5, confirming successful incorporation of the pH-responsive group. Encapsulation and controlled release of mycophenolate mofetil are efficiently demonstrated, with 90% release observed at intestinal pH. In vitro cell culture studies confirmed biocompatibility, showing no toxicity or adverse effects on Caco-2 cells. In vivo oral rat studies indicated reduced drug absorption in the stomach and enhanced absorption in the small intestine with the developed formulation. This research presents a promising drug delivery system with potential applications in the treatment of inflammatory bowel disease.

Gastroretentive Raft Forming System for Enhancing Therapeutic Effect of Drug-Loaded Hollow Mesoporous Silica on Gastric Ulcers

Gastric ulcers are characterized by damage to the stomach lining and are often triggered by substances such as ethanol and non-steroidal anti-inflammatory drugs. Patchouli alcohol (PA) has demonstrated effectiveness in treating gastric ulcers through antioxidative and anti-inflammatory effects. However, the water insolubility of PA and rapid gastric emptying cause low drug concentration and poor absorption in the stomach, resulting in limited treatment efficacy of PA. This study develops an oral gastroretentive raft forming system (GRFDDS) containing the aminated hollow mesoporous silica nanoparticles (NH2-HMSN) for PA delivery. The application of NH2-HMSN can enhance PA-loading capacity and water dispersibility, promoting bio-adhesion to the gastric mucosa and sustained drug release. The incorporation of PA-loaded NH2-HMSN (NH2-HMSN-PA) into GRFDDS can facilitate gastric drug retention and achieve long action, thereby improving therapeutic effects. The results reveal that NH2-HMSN-PA protects the gastric mucosa damage by inhibiting NLRP3-mediated pyroptosis. The GRFDDS, optimized through orthogonal design, demonstrates the gastric retention capacity and sustained drug release, exhibiting significant therapy efficacy in an ethanol-induced acute gastric ulcers model and an aspirin-induced chronic gastric ulcers model through antioxidation, anti-pyroptosis, and anti-inflammation. This study provides a potential strategy for enhancing druggability of insoluble natural compounds and therapeutic management of gastric ulcers.

Investigation of the mucin-nanoparticle interactions via real-time monitoring by microbalance and kinetic model simulation

Interactions between nanoparticles and the mucus layer are crucial to understand the behaviours in biological environments and design drug delivery systems. In this study, we developed a kinetic deposition model for the dynamic mucin-nanoparticle interactions using quartz crystal microbalance with dissipation (QCM-D). We investigated the effects of the physiochemical properties of several nanoparticles (including size, charge, and shape) and the physiological conditions on the mucin-nanoparticle interaction. Interestingly, layered double hydroxide (LDH) nanoparticles showed stronger interactions with the mucus layer compared to other types of nanoparticles due to their unique plate-like morphology. In specific for sheet-like LDH nanoparticles, our model found that their equilibrium adsorption capacity (Qe) followed the Langmuir adsorption isotherm, and the adsorption rate (k1) increased proportionally with the nanoparticle concentration. In addition, the particle size and thickness affected Qe and the surface coverage. Furthermore, bovine serum albumin (BSA) coating dramatically increased k1 of LDH nanoparticles. We proposed a novel mechanism to elucidate mucin-nanoparticle interactions, shedding light on the synergistic roles of drag force (Fd), repulsive force (Fr), and adsorptive force (Fa). These findings offer valuable insights into the complex mucin-nanoparticle interactions and provide guidance for the design of drug delivery systems.

"3-in-1" Hybrid Biocatalysts: Association of Yeast Cells Immobilized in a Sol-Gel Matrix for Determining Sewage Pollution

This study presents a novel ″3-in-1″ hybrid biocatalyst design that combines the individual efficiency of microorganisms while avoiding negative interactions between them. Yeast cells of Ogataea polymorpha VKM Y-2559, Blastobotrys adeninivorans VKM Y-2677, and Debaryomyces hansenii VKM Y-2482 were immobilized in an organosilicon material by using the sol-gel method, resulting in a hybrid biocatalyst. The catalytic activity of the immobilized microorganism mixture was evaluated by employing it as the bioreceptor element of a biosensor. Optical and scanning electron microscopies were used to examine the morphology of the biohybrid material. Elemental distribution analysis confirmed the encapsulation of yeast cells in a matrix composed of methyltriethoxysilane (MTES) and tetraethoxysilane (TEOS) (85 and 15 vol %, respectively). The resulting heterogeneous biocatalyst exhibited excellent performance in determining the biochemical oxygen demand (BOD) index in real surface water samples, with a sensitivity coefficient of 50 ± 3 × 10-3·min-1, a concentration range of 0.3-31 mg/L, long-term stability for 25 days, and a relative standard deviation of 3.8%. These findings demonstrate the potential of the developed hybrid biocatalyst for effective pollution monitoring and wastewater treatment applications.

A Fast and Reliable Method Based on QCM-D Instrumentation for the Screening of Nanoparticle/Blood Protein Interactions

The interactions that nanoparticles have with blood proteins are crucial for their fate in vivo. Such interactions result in the formation of the protein corona around the nanoparticles, and studying them aids in nanoparticle optimization. Quartz crystal microbalance with dissipation monitoring (QCM-D) can be used for this study. The present work proposes a QCM-D method to study the interactions on polymeric nanoparticles with three different human blood proteins (albumin, fibrinogen and γ-globulin) by monitoring the frequency shifts of sensors immobilizing the selected proteins. Bare PEGylated and surfactant-coated poly-(D,L-lactide-co-glycolide) nanoparticles are tested. The QCM-D data are validated with DLS and UV-Vis experiments in which changes in the size and optical density of nanoparticle/protein blends are monitored. We find that the bare nanoparticles have a high affinity towards fibrinogen and γ-globulin, with measured frequency shifts around -210 Hz and -50 Hz, respectively. PEGylation greatly reduces these interactions (frequency shifts around -5 Hz and -10 Hz for fibrinogen and γ-globulin, respectively), while the surfactant appears to increase them (around -240 Hz and -100 Hz and -30 Hz for albumin). The QCM-D data are confirmed by the increase in the nanoparticle size over time (up to 3300% in surfactant-coated nanoparticles), measured by DLS in protein-incubated samples, and by the trends of the optical densities, measured by UV-Vis. The results indicate that the proposed approach is valid for studying the interactions between nanoparticles and blood proteins, and the study paves the way for a more comprehensive analysis of the whole protein corona.