Baicalein loaded liposome with hyaluronic acid and Polyhexamethylene guanidine modification for anti methicillin-resistant Staphylococcus aureus infection.

Targeting delivery to the infection site and good affinity of vehicle to the bacterial are two main concerns in therapy of bacterial infection, and on-demand release of drug is another important issue. In this work, a liposome drug delivery system (HA/P/BAI-lip) incorporated with baicalein and modified by PHMG and HA was prepared. Several characterizations were conducted to examine the physical properties of liposome. Then it was applied to treatments of MRSA induced dorsal subcutaneous abscess model and the thigh muscle infected model. The presence of guanidine group in HA/P/BAI-lip rendered the liposome satisfactory bacterial target ability and good pH sensitive properties. The lipase secreted by bacterial could promote the hydrolysis of soybean phosphatidylcholine (SPC) in liposome. The modification of HA in HA/P/BAI-lip could lead the drug system to the exact infected site where CD44 was abundant because of inflammation. The low pH microenvironment characteristic of bacterial infection could induce the swelling of liposome following by degradation. Taken together, baicalein could be released selectively at the infected site to exert antibacterial capacity. HA/P/BAI-lip showed impressive antibacterial ability and dramatically decrease the bacterial burden of infection site and alleviate the infiltration of inflammatory cells, facilitating the recovery of infection.

Combined ROS Sensitive Folate Receptor Targeted Micellar Formulations of Curcumin Effective Against Rheumatoid Arthritis in Rat Model.

Introduction: Rheumatoid arthritis (RA) is an inflammatory immune-mediated disease that involves synovitis, cartilage destruction, and even joint damage. Traditional agents used for RA therapy remain unsatisfactory because of their low efficiency and obvious adverse effects. Therefore, we here established RA microenvironment-responsive targeted micelles that can respond to the increase in reactive oxygen species (ROS) levels in the joint and improve macrophage-specific targeting of loaded drugs. Methods: We here prepared ROS-responsive folate-modified curcumin micelles (TK-FA-Cur-Ms) in which thioketal (TK) was used as a ROS-responsive linker for modifying polyethylene glycol 5000 (PEG5000) on the micellar surface. When micelles were in the ROS-overexpressing inflammatory microenvironment, the PEG5000 hydration layer was shed, and the targeting ligand FA was exposed, thereby enhancing cellular uptake by macrophages through active targeting. The targeting, ROS sensitivity and anti-inflammatory properties of the micelles were assessed in vitro. Collagen-induced arthritis (CIA) rats model was utilized to investigate the targeting, expression of serum inflammatory factors and histology change of the articular cartilage by micelles in vivo. Results: TK-FA-Cur-Ms had a particle size of 90.07 ± 3.44 nm, which decreased to 78.87 ± 2.41 nm after incubation with H2O2. The micelles exhibited in vitro targeting of RAW264.7 cells and significantly inhibited inflammatory cytokine levels. Pharmacodynamic studies have revealed that TK-FA-Cur-Ms prolonged the drug circulation and exhibited augmented cartilage-protective and anti-inflammatory effects in vivo. Conclusion: The unique ROS-responsive targeted micelles with targeting, ROS sensitivity and anti-inflammatory properties were successfully prepared and may offer an effective therapeutic strategy against RA.

Menthol-Modified Quercetin Liposomes with Brain-Targeting Function for the Treatment of Senescent Alzheimer's Disease.

Oxidative stress and neuroinflammation in the aging brain are correlated with the development of neurodegenerative diseases, such as Alzheimer's disease (AD). The blood-brain barrier (BBB) poses a significant challenge to the effective delivery of therapeutics for AD. Prior research has demonstrated that menthol (Men) can augment the permeability of the BBB. Consequently, in the current study, we modified Men on the surface of liposomes to construct menthol-modified quercetin liposomes (Men-Qu-Lips), designed to cross the BBB and enhance quercetin (Qu) concentration in the brain for improved therapeutic efficacy. The experimental findings indicate that Men-Qu-Lips exhibited good encapsulation efficiency and stability, successfully crossed the BBB, improved oxidative stress and neuroinflammation in the brains of aged mice, protected neurons, and enhanced their learning and memory abilities.

Borneol-modified docetaxel plus tetrandrine micelles for treatment of drug-resistant brain glioma.

OBJECTIVE: Glioma is the most common and deadly primary malignant tumor in adults. Treatment outcomes are ungratified due to the presence of blood-brain barrier (BBB), glioma stem cells (GSCs) and multidrug resistance (MDR). Docetaxel (DTX) is considered as a potential drug for the treatment of brain tumor, but its effectiveness is limited by its low bioavailability and drug resistance. Tetrandrine (TET) reverses the resistance of tumor cells to chemotherapy drugs. Borneol (BO) modified in micelles has been shown to promote DTX plus TET to cross the BBB, allowing the drug to better act on tumors. Therefore, we constructed BO-modified DTX plus TET micelles to inhibit chemotherapeutic drug resistance. SIGNIFICANCE: Provide a new treatment method for drug-resistant brain gliomas. METHODS: In this study, BO-modified DTX plus TET micelles were prepared by thin film dispersion method, their physicochemical properties were characterized. Its targeting ability was investigated. The therapeutic effect on GSCs was investigated by in vivo and in vitro experiments. RESULTS: The BO-modified DTX plus TET micelles were successfully constructed by thin film dispersion method, and the micelles showed good stability. The results showed that targeting micelles increased bEnd.3 uptake and helped drugs cross the BBB in vitro. And we also found that targeting micelles could inhibit cell proliferation, promote cell apoptosis and inhibit the expression of drug-resistant protein, thus provide a new treatment method for GSCs in vitro and in vivo. CONCLUSIONS: BO-modified DTX plus TET micelles may provide a new treatment method for drug-resistant brain gliomas.

Development of a Brain-Targeted Nano Drug Delivery System to Enhance the Treatment of Neurodegenerative Effects of Resveratrol.

As the aging population continues to increase, aging-related inflammation, oxidative stress, and neurodegenerative diseases have become serious global health threats. Resveratrol, a star molecule in natural polyphenols, has been widely reported to have physiological activities such as anti-aging, anti-inflammatory, antioxidant, and neuroprotection. However, its poor water solubility, rapid metabolism, low bioavailability and poor targeting ability, which limits its application. Accordingly, a brain-targeted resveratrol liposome (ANG-RES-LIP) was developed to solve these issues. Experimental results showed that ANG-RES-LIP has a uniform size distribution, good biocompatibility, and a drug encapsulation rate of over 90%. Furthermore, in vitro cell experiments showed that the modification of the targeting ligand ANG significantly increased the capability of RES to cross the BBB and neuronal uptake. Compared with free RES, ANG-RES-LIP demonstrated stronger antioxidant activity and the ability to rescue oxidatively damaged cells from apoptosis. Additionally, ANG-RES-LIP showed the ability to repair damaged neuronal mitochondrial membrane potential. In vivo experiments further demonstrated that ANG-RES-LIP improved cognitive function by reducing oxidative stress and inflammation levels in the brains of aging model mice, repairing damaged neurons and glial cells, and increasing brain-derived neurotrophic factor. In summary, this study not only provides a new method for further development and application of resveratrol but also a promising strategy for preventing and treating age-related neurodegenerative diseases.

ApoE-modified liposomes encapsulating resveratrol and salidroside alleviate manifestations of Alzheimer's disease in APP/PS-1 mice.

OBJECTIVE: Alzheimer's disease (AD) is a neurodegenerative disease that is associated with aging and is influenced by both genetic and environmental factors. Several studies and clinical trials have demonstrated that resveratrol (Res) and salidroside (Sal) are not only biologically safe but also influence AD biomarker trajectories. However, their clinical applications have been quite limited due to poor specificity, low solubility, and insufficient blood-brain barrier (BBB) penetration. Therefore, we developed a nano-drug delivery system in which Res and Sal were encapsulated in liposomes, which were surface-modified with ApoE (ApoE-Res/Sal-Lips) to compensate for these deficiencies. METHOD: In this study, ApoE-Res/Sal-Lips were prepared using a standard thin-film hydration method for liposomes. Then, cellular uptake of the loaded liposomes was assessed in vitro using fluorescent staining assays. A BBB model was constructed to investigate the capacity of the liposomes to cross the BBB in vitro, and the ability of liposomes to target the brain was observed by in vivo imaging. In addition, the neuroprotective effects of the different liposome formulations in APP/PS-1 mice were evaluated by measuring the changes in levels of oxidative, anti-inflammatory, and anti-apoptotic factors in the mice brains. RESULTS: In vitro, ApoE-Res/Sal-Lips increased the uptake of Res and Sal by bEnd.3 and N2a cells, enhanced BBB penetration, and improved transport efficiency. In vivo, the ApoE-Res/Sal-Lips were found to alleviate AD pathological symptoms, reduce learning and memory impairments, and improve brain function. CONCLUSION: ApoE-Res/Sal-Lips provide a new method for the treatment of AD.

Study on Wastewater Demulsification Technology of Crude Oil in Xinjiang Oilfield.

The Second Oil Production Plant of Xinjiang Oilfield produces a large amount of highly emulsified crude oil, which has a serious impact on the subsequent oil-water separation. At present, the concentration of demulsifier has increased to 2000 mg/L, but the demulsification effect is still poor. In this paper, the source and physical properties of highly emulsified crude oil are investigated firstly. The results show that highly emulsified crude oil is composed of three kinds of liquid: (1) conventional water flooding (WF); (2) chemical flooding (CF); (3) fracturing backflow fluid (FB). Among them, high zeta potential, low density difference, high viscosity, and small emulsion particles are responsible for the difficulty in the demulsification of the WF emulsion, while the high pH value is the reason why the CF emulsion is difficult to demulsify. Therefore, systematic experiments were implemented to investigate the optimal demulsification approach towards the three liquids above. As for the WF emulsion, it was necessary to raise the temperature to 70 °C and the concentration of the demulsifier to 200 mg/L. Moreover, it was only necessary to add 200 mg/L of demulsifier to break the CF emulsion after adjusting the pH value to 7, while no extra treatments were needed to break the FB emulsion. We hope this study can provide a new insight for the treatment of emulsions in the later stage of oilfield development.

Multifunctional icariin and tanshinone IIA co-delivery liposomes with potential application for Alzheimer's disease.

The blood-brain barrier (BBB) is a protective barrier for brain safety, but it is also a major obstacle to the delivery of drugs to the cerebral parenchyma such as the hippocampus, hindering the treatment of central nervous system diseases such as Alzheimer's disease (AD). In this work, an anti-AD brain-targeted nanodrug delivery system by co-loading icariin (ICA) and tanshinone IIA (TSIIA) into Aniopep-2-modified long-circulating (Ang2-ICA/TSIIA) liposomes was developed. Low-density lipoprotein receptor-related protein-1 (LRP1) was a receptor overexpressed on the BBB. Angiopep-2, a specific ligand of LRP1, exhibited a high binding efficiency with LRP1. Additionally, ICA and TSIIA, drugs with neuroprotective effects are loaded into the liposomes, so that the liposomes not only have an effective BBB penetration effect, but also have a potential anti-AD effect. The prepared Ang2-ICA/TSIIA liposomes appeared narrow dispersity and good stability with a diameter of 110 nm, and a round morphology. Cell uptake observations, BBB models in vitro, and imaging analysis in vivo showed that Ang2-ICA/TSIIA liposomes not only penetrate the BBB through endocytosis, but also accumulate in N2a cells or brain tissue. The pharmacodynamic analysis in vivo demonstrated that Ang2-ICA/TSIIA liposomes could improve AD-like pathological features in APP/PS1 mice, including inhibiting neuroinflammation and oxidative stress, reducing apoptosis, protecting neurons, and improving cognitive function. Therefore, Ang2-ICA/TSIIA liposomes are considered a potentially effective therapeutic strategy for AD.

Folate-modified triptolide liposomes target activated macrophages for safe rheumatoid arthritis therapy.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial joint hyperplasia, joint inflammation, cartilage erosion and bone destruction. Macrophages play an essential role in the pathogenesis of RA, and folate receptor ß (FR-ß) is highly expressed on the surface of activated synovial macrophages in RA patients. Triptolide (TP) has anti-inflammatory properties, and it can protect the cartilage matrix, but its clinical application has been limited due to poor solubility, low bioavailability and systemic toxicity. Therefore, we constructed folate-modified triptolide liposomes (FA-TP-Lips) to target macrophages, thereby treating RA in a safe and effective way. The experiments indicated that FA-TP-Lips had properties of small particle size, uniform particle size distribution, high drug encapsulation and long circulation. Furthermore, FA-TP-Lips showed reduced cytotoxicity, increased cellular uptake and significant anti-inflammatory effects in vitro. It also inhibited osteoclastogenesis. In vivo experiments revealed that liposomes could prolong the circulation of TP in the body, as well as exhibit significant cartilage-protective and anti-inflammatory effects with lower toxicity compared with the free TP group, thereby providing a promising new approach for the treatment of RA.