Perfluorocarbon Nanodroplets for Dual Delivery with Ultrasound/GSH-Responsive Release of Model Drug and Passive Release of Nitric Oxide

Insulative Compression of Neuronal Tissues on Microelectrode Arrays by Perfluorodecalin Enhances Electrophysiological Measurements

Microelectrode array (MEA) techniques provide a powerful method for exploration of neural network dynamics. A critical challenge is to interface 3D neural tissues including neural organoids with the flat MEAs surface, as it is essential to place neurons near to the electrodes for recording weak extracellular signals of neurons. To enhance performance of MEAs, most research have focused on improving their surface treatment, while little attention has been given to improve the tissue-MEA interactions from the medium side. Here, a strategy is introduced to augment MEA measurements by overlaying perfluorodecalin (PFD), a biocompatible fluorinated solvent, over neural tissues. Laying PFD over cerebral organoids insulates and compresses the tissues on MEA, which significantly enhances electrophysiological recordings. Even subtle signals such as the propagation of action potentials in bundled axons of motor nerve organoids can be detected with the technique. Moreover, PFD stabilizes tissues in acute recordings and its transparency allows optogenetic manipulations. This research highlights the potential of PFD as a tool for refining electrophysiological measurements of in vitro neuronal cultures. This can open new avenues to leverage precision of neuroscientific investigations and expanding the toolkit for in vitro studies of neural function and connectivity.

Pharmacokinetic and Pharmacodynamic Study of Folic Acid-Modified Chitosan-Stearic Acid Nanomicelles Loaded with Tetrandrine for Rheumatoid Arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a chronic autoimmune disease, and it is currently incurable. Tetrandrine (TET) has an obvious curative effect with therapeutic efficacy on RA, but its use is limited due to its poor water-solubility and bioavailability. Therefore, TET-loaded nanomicelles modified with chitosan, stearic acid, and folic acid (FCST) was prepared in the study, and the pharmacokinetics and pharmacodynamics were studied.

METHODS

The plasma concentrations of FCST and TET were measured by the PLC-MS/MS method at different times, and the pharmacokinetic parameters were calculated. A collagen-induced arthritis (CIA) model was established with rats. On the 16th day after the first immunization, 50 rats were randomized into five groups with 10 rats in each group according to the arthritis score. The drugs were administered by intraperitoneal injection for 30 days. The swelling degree and joint score of the rats were tested during each administration. In addition, the pro-inflammatory factors IL-1β, IL-6, IL-17, and TNF-α in the serum of the rats were tested by an ELISA kit, and their joints were examined by histopathology.

RESULTS

Pharmacokinetic studies showed that the AUC0-72h of FCST was 1.93 times that of TET. FCST demonstrated higher bioavailability compared to TET (p < 0.05). Pharmacodynamic studies demonstrated that FCST had significant anti-inflammatory effects, and its anti-inflammatory activity was stronger compared to the same dose of TET, as evidenced by measuring toe thickness and observing toe appearance. It significantly reduced the expression of IL-1, IL-6, IL-17, and TNF-α in rats with rheumatoid arthritis (p < 0.05).

CONCLUSIONS

FCST can significantly improve bioavailability and has a significant therapeutic effect on rheumatoid arthritis.

Synthesis and Antioxidant Effects of Edaravone-Loaded MPEG-2000-DSPE Micelles in Rotenone-Induced PC12 Cell Model of Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder globally that lacks any disease-modifying drug for prevention or treatment. Oxidative stress has been identified as one of the key pathogenic drivers of Parkinson's disease (PD). Edaravone, an approved free-radical scavenger, has proven to have potential against PD by targeting multiple key pathologies, including oxidative stress, focal mitochondria, and neuroinflammation. However, its bioavailability is potentially restricted due to its poor solubility and short half-life. This study aims to develop a simple and effective drug delivery system for edaravone to enhance its solubility, stability, and bioavailability to improve its neuroprotective efficacy. An MPEG-2000-DSPE-edaravone (MDE) micelle was prepared via solvent evaporation using MPEG-2000-DSPE as a carrier to encapsulate edaravone. The morphology, particle size, zeta potential, chemical structure, and edaravone loading of MDE were evaluated. We then investigated whether such targeted edaravone delivery could provide enhanced neuroprotection. A cell model of PD was established in PC12 cells through exposure to rotenone. The effects of MDE on PC12 cells treated with or without rotenone were evaluated using a cell counting kit-8, calcein acetoxymethyl ester (AM)-propidine iodide (PI) staining, and flow cytometry. Cell migration was evaluated using a wound healing assay. Additionally, the intracellular antioxidant study was performed using an ROS-level-detecting DCFH-DA probe, and the mitochondrial membrane potentials were evaluated using a JC-1 assay. MDE with a drug-loading content of 17.6% and an encapsulation efficiency of 92.8% was successfully prepared. The resultant MDE had a mean particle size of 112.97 ± 5.54 nm with a zeta potential of -42 mV. Cytotoxicity assays confirmed that the MDE (≤200 ug/mL) exhibited promising cytocompatibility with no significant effect on cell viability, cell cycle regulation, or apoptosis levels. Likewise, compared with the free edaravone, no effect on cell migration was noted for MDE. MDE might be able to target edaravone delivery into PC12 cells, increasing the mitochondrial membrane potential and providing a significant local antioxidant effect. The results demonstrated that MPEG-2000-DSPE could be a promising material for enhancing edaravone's aqueous solubility, stability, and antioxidant effects. MDE could be a potential drug formulation for treating PD and other diseases in which oxidative stress plays a key role in pathogenesis.

Investigation of Ultrasound Mediated Extravasation of a Model Drug by Perfluorobutane Nanodroplets

OBJECTIVE

Perfluorocarbon nanodroplets (NDs) have been widely investigated as both diagnostic and therapeutic agents. There remains, however, a challenge in generating NDs that do not vaporize spontaneously but can be activated at ultrasound pressures that do not produce unwanted bioeffects. In previous work, it has been shown that phospholipid-coated perfluorobutane (PFB) NDs can potentially overcome this challenge. The aim of this study was to investigate whether these NDs can promote drug delivery.

METHODS

A combination of high-speed optical imaging and passive cavitation detection was used to study the acoustic properties of the PFB-NDs in a tissue mimicking phantom. PFB-NDs were exposed to ultrasound at frequencies from 0.5 to 1.5 MHz and peak negative pressures from 0.5 to 3.5 MPa. In addition, the penetration depth of two model drugs (Nile Red and 200 nm diameter fluorescent polymer spheres) into the phantom was measured.

RESULTS

PFB NDs were found to be stable in aqueous suspension at both 4°C and 37°C; their size remaining unchanged at 215 ± 11 nm over 24 h. Penetration of both model drugs in the phantom was found to increase with increasing ultrasound peak negative pressure and decreasing frequency and was found to be positively correlated with the energy of acoustic emissions. Extravasation depths >1 mm were observed at 0.5 MHz with pressures <1 MPa.

CONCLUSION

The results of the study thus suggest that PFB NDs can be used both as drug carriers and as nuclei for cavitation to enhance drug delivery without the need for high intensity ultrasound.

ROS-responsive polyprodrug micelles carrying suicide genes in combination with chemotherapy and gene therapy for prostate cancer treatment

Prostate cancer is the most common malignant tumor in the male reproductive system, and its incidence increases with age. Chemotherapy is one of the main strategies for treating prostate cancer, but it often comes with unavoidable side effects. Nanocarriers can improve drug utilization and targeting, and cationic carriers can also carry nucleic acids for gene therapy. In this study, we prepared a cationic micelle constructed from a polyprodrug that can deliver both chemotherapeutic drugs and nucleic acids simultaneously. The typical chemotherapeutic drug hydroxycamptothecin (HCPT) was linked by reactive oxygen species (ROS)-responsive coupling agents and forms amphiphilic block polymers with low molecular weight polyethyleneimine (PEI). The resulting cationic micelles can be triggered by high levels of ROS in tumor cells and collapse to release HCPT and suicide genes to kill tumor cells. At the same time, it reduces the killing of normal cells. In prostate cancer cells, it has been confirmed that the co-delivery carriers combined with chemotherapy and a suicide gene prodrug system have shown an ideal therapeutic effect on prostate cancer.

Ultrasound-Triggered Piezocatalysis for Selectively Controlled NO Gas and Chemodrug Release to Enhance Drug Penetration in Pancreatic Cancer

Nitric oxide (NO) is drawing widespread attention in treating pancreatic ductal adenocarcinoma (PDAC) as a safe and therapeutically efficient technique through modulating the dense fibrotic stroma in the tumor microenvironment to enhance drug penetration. Considerable NO nanogenerators and NO releasing molecules have been developed to shield the systemic toxicity caused by free diffusion of NO gas. However, on-demand controlled release of NO and chemotherapy drugs at tumor sites remains a problem limited by the complex and dynamic tumor microenvironment. Herein, we present an ultrasound-responsive nanoprodrug of CPT-t-R-PEG₂₀₀₀@BaTiO₃ (CRB) which encapsulates piezoelectric nanomaterials barium titanate nanoparticle (BaTiO₃) with amphiphilic prodrug molecules that consisted of thioketal bond (t) linked chemotherapy drug camptothecin (CPT) and NO-donor l-arginine (R). Based on ultrasound-triggered piezocatalysis, BaTiO₃ can continuously generate ROS in the hypoxic tumor environment, which induces a cascade of reaction processes to break the thioketal bond to release CPT and oxidize R to release NO, simultaneously delivering CPT and NO to the tumor site. It is revealed that CRB shows a uniform size distribution, prolonged blood circulation time, and excellent tumor targeting ability. Moreover, controlled release of CPT and NO were observed both in vitro and in vivo under the stimulation of ultrasound, which is beneficial to the depletion of dense stroma and subsequently enhanced delivery and efficacy of CPT. Taken together, CRB significantly increased the antitumor efficacy against highly malignant Panc02 tumors in mice through inhibiting chemoresistance, representing a feasible approach for targeted therapies against Panc02 and other PDAC.

Recent Advances in Stimuli-Responsive Doxorubicin Delivery Systems for Liver Cancer Therapy

Doxorubicin (DOX) is one of the most commonly used drugs in liver cancer. Unfortunately, the traditional chemotherapy with DOX presents many limitations, such as a systematic release of DOX, affecting both tumor tissue and healthy tissue, leading to the apparition of many side effects, multidrug resistance (MDR), and poor water solubility. Furthermore, drug delivery systems' responsiveness has been intensively studied according to the influence of different internal and external stimuli on the efficiency of therapeutic drugs. In this review, we discuss both internal stimuli-responsive drug-delivery systems, such as redox, pH and temperature variation, and external stimuli-responsive drug-delivery systems, such as the application of magnetic, photo-thermal, and electrical stimuli, for the controlled release of Doxorubicin in liver cancer therapy, along with the future perspectives of these smart delivery systems in liver cancer therapy.