Liposome Drug Delivery System across Endothelial Plasma Membrane: Role of Distance between Endothelial Cells and Blood Flow Rate

Efficiency of PGK1 proteins delivered to the brain via a liposomal system through intranasal route administration for the treatment of spinocerebellar ataxia type 3

A patient-friendly and efficient treatment method for patients with spinocerebellar ataxia type 3 (SCA3) was provided through a nose-to-brain liposomal system. Initially, PGK1 was overexpressed in HEK 293-84Q-GFP diseased cells (HEK 293-84Q-GFP-PGK1 cells) to confirm its effect on the diseased protein polyQ. A decrease in polyQ expression was demonstrated in HEK 293-84Q-GFP-PGK1 cells compared to HEK 293-84Q-GFP parental cells. Subsequently, PGK1 was encapsulated in a liposomal system to evaluate its therapeutic efficiency in SCA3. The optimized liposomes exhibited a significantly enhanced positive charge, facilitating efficient intracellular protein delivery to the cells. The proteins were encapsulated within the liposomes using an optimized method involving a combination of heat shock and sonication. The liposomal system was further demonstrated to be deliverable to the brain via intranasal administration. PGK1/liposomes were intranasally delivered to SCA3 mice, which subsequently exhibited an amelioration of motor impairment, as assessed via the accelerated rotarod test. Additionally, fewer shrunken morphology Purkinje cells and a reduction in polyQ expression were observed in SCA3 mice that received PGK1/liposomes but not in the untreated, liposome-only, or PGK1-only groups. This study provides a non-invasive route for protein delivery and greater delivery efficiency via the liposomal system for treating neurodegenerative diseases.

Clinical significance of small extracellular vesicles in cholangiocarcinoma

Cholangiocarcinoma is an aggressive and heterogeneous malignancy originating from the bile duct epithelium. It is associated with poor prognosis and high mortality. The global incidence of cholangiocarcinoma is rising, and there is an urgent need for effective early diagnosis and treatment strategies to reduce the burden of this devastating tumor. Small extracellular vesicles, including exosomes and microparticles, are nanoscale vesicles formed by membranes that are released both normally and pathologically from cells, mediating the intercellular transfer of substances and information. Recent studies have demonstrated the involvement of small extracellular vesicles in numerous biological processes, as well as the proliferation, invasion, and metastasis of tumor cells. The present review summarizes the tumorigenic roles of small extracellular vesicles in the cholangiocarcinoma microenvironment. Owing to their unique composition, accessibility, and stability in biological fluids, small extracellular vesicles have emerged as ideal biomarkers for use in liquid biopsies for diagnosing and outcome prediction of cholangiocarcinoma. Specific tissue tropism, theoretical biocompatibility, low clearance, and strong biological barrier penetration of small extracellular vesicles make them suitable drug carriers for cancer therapy. Furthermore, the potential value of small extracellular vesicle-based therapies for cholangiocarcinoma is also reviewed.

How can machine learning and multiscale modeling benefit ocular drug development?

The eyes possess sophisticated physiological structures, diverse disease targets, limited drug delivery space, distinctive barriers, and complicated biomechanical processes, requiring a more in-depth understanding of the interactions between drug delivery systems and biological systems for ocular formulation development. However, the tiny size of the eyes makes sampling difficult and invasive studies costly and ethically constrained. Developing ocular formulations following conventional trial-and-error formulation and manufacturing process screening procedures is inefficient. Along with the popularity of computational pharmaceutics, non-invasive in silico modeling & simulation offer new opportunities for the paradigm shift of ocular formulation development. The current work first systematically reviews the theoretical underpinnings, advanced applications, and unique advantages of data-driven machine learning and multiscale simulation approaches represented by molecular simulation, mathematical modeling, and pharmacokinetic (PK)/pharmacodynamic (PD) modeling for ocular drug development. Following this, a new computer-driven framework for rational pharmaceutical formulation design is proposed, inspired by the potential of in silico explorations in understanding drug delivery details and facilitating drug formulation design. Lastly, to promote the paradigm shift, integrated in silico methodologies were highlighted, and discussions on data challenges, model practicality, personalized modeling, regulatory science, interdisciplinary collaboration, and talent training were conducted in detail with a view to achieving more efficient objective-oriented pharmaceutical formulation design.

Internal Mammary Arteries as a Model to Demonstrate Restoration of the Impaired Vasodilation in Hypertension, Using Liposomal Delivery of the CYP1B1 Inhibitor, 2,3',4,5'-Tetramethoxystilbene

A significant number of patients with severe cardiovascular disease, undergoing coronary artery bypass grafting (CABG), present with hypertension. While internal mammary arteries (IMAs) may be a better alternative to vein grafts, their impaired vasodilator function affects their patency. Our objectives were to (1) determine if inhibition of the cytochrome P450 enzyme CYP1B1, using liposome-encapsulated 2,3′,4,5′-tetramethoxystilbene (TMS), can potentiate vasodilation of IMAs from CABG patients, and (2) assess mechanisms involved using coronary arteries from normal rats, in an ex vivo model of hypertension. PEGylated liposomes were synthesized and loaded with TMS (mean diameter 141 ± 0.9 nm). Liposomal delivery of TMS improved its bioavailability Compared to TMS solution (0.129 ± 0.02 ng/mL vs. 0.086 ± 0.01 ng/mL at 4 h; p < 0.05). TMS-loaded liposomes alleviated attenuated endothelial-dependent acetylcholine (ACh)-induced dilation in diseased IMAs (@ACh 10−4 M: 56.9 ± 5.1%; n = 8 vs. 12.7 ± 7.8%; n = 6; p < 0.01) for TMS-loaded liposomes vs. blank liposomes, respectively. The alleviation in dilation may be due to the potent inhibition of CYP1B1 by TMS, and subsequent reduction in reactive oxygen species (ROS) moieties and stimulation of nitric oxide synthesis. In isolated rat coronary arteries exposed to a hypertensive environment, TMS-loaded liposomes potentiated nitric oxide and endothelium-derived hyperpolarization pathways via AMPK. Our findings are promising for the future development of TMS-loaded liposomes as a promising therapeutic strategy to enhance TMS bioavailability and potentiate vasodilator function in hypertension, with relevance for early and long-term treatment of CABG patients, via the sustained and localized TMS release within IMAs.

Liposomes are Poorly Absorbed via Lung Lymph After Inhaled Administration in Sheep

Enhancing the delivery of therapeutic agents to the lung lymph, including drugs, transfection agents, vaccine antigens and vectors, has the potential to significantly improve the treatment and prevention of a range of lung-related illnesses. One way in which lymphatic delivery can be optimized is via the use of nanomaterial-based carriers, such as liposomes. After inhaled delivery however, there is conflicting information in the literature regarding whether nanomaterials can sufficiently access the lung lymphatics to have a therapeutic benefit, in large part due to a lack of reliable quantitative pharmacokinetic data. The aim of this work was to quantitatively evaluate the pulmonary lymphatic pharmacokinetics of a model nanomaterial-based drug delivery system (HSPC liposomes) in caudal mediastinal lymph duct cannulated sheep after nebulized administration to the lungs. Liposomes were labelled with ³H-phosphatidylcholine to facilitate evaluation of pharmacokinetics and biodistribution in biological samples. While nanomaterials administered to the lungs may access the lymphatics via direct absorption from the airways or after initial uptake by alveolar macrophages, only 0.3 and 0.001% of the ³H-lipid dose was recovered in lung lymph fluid and lymph cell pellets (containing immune cells) respectively over 5 days. This suggests limited lymphatic access of liposomes, despite apparent pulmonary bioavailability of the ³H-lipid being approximately 17%, likely a result of absorption of liberated ³H-lipid after breakdown of the liposome in the presence of lung surfactant. Similarly, biodistribution of ³H in the mediastinal lymph node was insignificant after 5 days. These data suggest that liposomes, that are normally absorbed via the lymphatics after interstitial administration, do not access the lung lymphatics after inhaled administration. Alternate approaches to maximize the lung lymphatic delivery of drugs and other therapeutics need to be identified.

Lipid-Based Nanoparticles for Targeted Delivery of the Anti-Cancer Drugs: A Review

Abstract:

Cancer is one of the main reasons for mortality worldwide. Chemotherapeutic agents have been effectively designed to increase certain patients' survival rates, but ordinarily designed chemotherapeutic agents necessarily deliver toxic chemotherapeutic drugs to healthy tissues, resulting in serious side effects. Cancer cells can often acquire drug resistance after repeated dosing of current chemotherapeutic agents, restricting their efficacy. Given such obstacles, investigators have attempted to distribute chemotherapeutic agents using targeted drug delivery systems (DDSs), especially nanotechnology-based DDSs. Lipid-Based Nanoparticles (LBNPs) are a large and complex class of substances that have been utilized to manage a variety of diseases, mostly cancer. Liposomes seem to be the most frequently employed LBNPs, owing to their high biocompatibility, bioactivity, stability, and flexibility; howbeit Solid Lipid Nanoparticles (SLNs) and Non-structured Lipid Carriers (NLCs) have lately received a lot of interest. Besides that, there are several reports that concentrate on novel therapies via LBNPs to manage various forms of cancer. In the present research, the latest improvements in the application of LBNPs have been shown to deliver different therapeutic agents to cancerous cells and have been demonstrated LBNPs also can be a quite successful candidate in cancer therapy for subsequent use.

Cellulosic Polymers for Enhancing Drug Bioavailability in Ocular Drug Delivery Systems

One of the major impediments to drug development is low aqueous solubility and thus poor bioavailability, which leads to insufficient clinical utility. Around 70–80% of drugs in the discovery pipeline are suffering from poor aqueous solubility and poor bioavailability, which is a major challenge when one has to develop an ocular drug delivery system. The outer lipid layer, pre-corneal, dynamic, and static ocular barriers limit drug availability to the targeted ocular tissues. Biopharmaceutical Classification System (BCS) class II drugs with adequate permeability and limited or no aqueous solubility have been extensively studied for various polymer-based solubility enhancement approaches. The hydrophilic nature of cellulosic polymers and their tunable properties make them the polymers of choice in various solubility-enhancement techniques. This review focuses on various cellulose derivatives, specifically, their role, current status and novel modified cellulosic polymers for enhancing the bioavailability of BCS class II drugs in ocular drug delivery systems.

Delivery of trans-membrane proteins by liposomes; the effect of liposome size and formulation technique on the efficiency of protein delivery

Channelopathies are disorders caused by reduced expression or impaired function of ion channels. Most current therapies rely on symptomatic treatment without addressing the underlying cause. We have recently established proof of principle for delivery of functional ion channel protein into the membrane of target cells using fusogenic liposomes incorporating glycine receptor (GlyR)-containing cell membrane fragments (CMF) that were formulated by thin film hydration. Here, the effect of liposome size and the formulation technique on the performance of the delivery vehicle was assessed. Three types of liposomes were prepared using lecithin and cholesterol, (i) small (SL), and (ii) large (LL) liposomes made by thin film hydration, and (iii) small liposomes prepared by vortex agitation (V-SL). All liposomes were evaluated for their ability to (i) incorporate GlyR-rich CMF, (ii) fuse with the cell membrane of target cells and (iii) deliver functional GlyR, as assessed by patch-clamp electrophysiology. SL prepared by thin film hydration offered the most effective delivery of glycine receptors that gave clear glycine-mediated currents in target cells. LL showed higher incorporation of CMF, but did not effectively fuse with the target cell membrane, while V-SL did not incorporate sufficient amounts of CMF. Additionally, SL showed minimalin vivotoxicity upon intrathecal injection in mice. Thus, liposome-mediated delivery of membrane proteins may be a promising therapeutic approach for the treatment of channelopathies.