Exosome-based bone-targeting drug delivery alleviates impaired osteoblastic bone formation and bone loss in inflammatory bowel diseases

Current Strategies for Exosome Cargo Loading and Targeting Delivery

Extracellular vesicles (EVs) such as ectosomes and exosomes have gained attention as promising natural carriers for drug delivery. Exosomes, which range from 30 to 100 nm in diameter, possess a lipid bilayer and are secreted by various cells. Due to their high biocompatibility, stability, and low immunogenicity, exosomes are favored as cargo carriers. The lipid bilayer membrane of exosomes also offers protection against cargo degradation, making them a desirable candidate for drug delivery. However, loading cargo into exosomes remains to be a challenge. Despite various strategies such as incubation, electroporation, sonication, extrusion, freeze-thaw cycling, and transfection that have been developed to facilitate cargo loading, inadequate efficiency still persists. This review offers an overview of current cargo delivery strategies using exosomes and summarizes recent approaches for loading small-molecule, nucleic acid, and protein drugs into exosomes. With insights from these studies, we provide ideas for more efficient and effective delivery of drug molecules by using exosomes.

The Preventive Effects of Probiotic Prevotella histicola on the Bone Loss of Mice with Ovariectomy-Mediated Osteoporosis

It has been demonstrated that the disturbance of gut microbiota (GM) is closely related to the reduction of bone mass and incidence of osteoporosis (OP). The aim of this study is to investigate whether the supplementation of Prevotella histicola (Ph) can prevent the bone loss in mice with ovariectomy (OVX)-mediated OP, and further explore relevant mechanisms. Regular (once a day for 8 consecutive weeks) and quantitative (200 µL/d) perfusion of Ph (the bacteria that orally gavaged) was conducted starting from 1 week after the construction of mice models. Bone mass and bone microstructure were detected by Micro-computed tomography (Micro-CT). Expressions of intestinal permeability, pro-inflammatory cytokines, and osteogenic and osteoclastic activities of mice were analyzed by histological staining and immunohistochemistry (IHC). 16S rRNA high throughput sequencing technique was applied to analyze the alterations of composition, abundance, and diversity of collected feces. Regular and quantitative perfusion of Ph mitigated the bone loss in mice with OVX-mediated OP. Compared with OVX + PBS group, perfusion of Ph repressed osteoclastogenesis and promoted osteogenesis, reduced release of pro-inflammatory cytokine cytokines (interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α)), and reversed expressions of tight junction proteins (zonula occludens protein 1 (ZO-1) and Occludin). Besides, the perfusion of Ph improved the composition, abundance, and diversity of GM. Collectively, this study revealed that regular and quantitative perfusion of Ph can improve the bone loss in mice with OVX-mediated OP by repairing intestinal mucosal barrier damage, optimizing intestinal permeability, inhibiting release of pro-osteoclastogenic cytokines, and improving disturbance of GM.

Endogenous Lipid Carriers-Bench-to-Bedside Roadblocks in Production and Drug Loading of Exosomes

Exosomes are cell-derived, nano-sized extracellular vesicles comprising a lipid bilayer membrane that encapsulates several biological components, such as nucleic acids, lipids, and proteins. The role of exosomes in cell-cell communication and cargo transport has made them promising candidates in drug delivery for an array of diseases. Despite several research and review papers describing the salient features of exosomes as nanocarriers for drug delivery, there are no FDA-approved commercial therapeutics based on exosomes. Several fundamental challenges, such as the large-scale production and reproducibility of batches, have hindered the bench-to-bedside translation of exosomes. In fact, compatibility and poor drug loading sabotage the possibility of delivering several drug molecules. This review provides an overview of the challenges and summarizes the potential solutions/approaches to facilitate the clinical development of exosomal nanocarriers.

Extracellular vesicles as a new horizon in the diagnosis and treatment of inflammatory eye diseases: A narrative review of the literature

Extracellular vesicles include exosomes, microvesicles, and apoptotic bodies. Their cargos contain a diverse variety of lipids, proteins, and nucleic acids that are involved in both normal physiology and pathology of the ocular system. Thus, studying extracellular vesicles may lead to a more comprehensive understanding of the pathogenesis, diagnosis, and even potential treatments for various diseases. The roles of extracellular vesicles in inflammatory eye disorders have been widely investigated in recent years. The term "inflammatory eye diseases" refers to a variety of eye conditions such as inflammation-related diseases, degenerative conditions with remarkable inflammatory components, neuropathy, and tumors. This study presents an overview of extracellular vesicles' and exosomes' pathogenic, diagnostic, and therapeutic values in inflammatory eye diseases, as well as existing and potential challenges.

An Update on the Emerging Role of Wnt/β-catenin, SYK, PI3K/AKT, and GM-CSF Signaling Pathways in Rheumatoid Arthritis

Rheumatoid arthritis is an untreatable autoimmune disorder. The disease is accompanied by joint impairment and anomalies, which negatively affect the patient's quality of life and contribute to a decline in manpower. To diagnose and treat rheumatoid arthritis, it is crucial to understand the abnormal signaling pathways that contribute to the disease. This understanding will help develop new rheumatoid arthritis-related intervention targets. Over the last few decades, researchers have given more attention to rheumatoid arthritis. The current review seeks to provide a detailed summary of rheumatoid arthritis, highlighting the basic description of the disease, past occurrences, the study of epidemiology, risk elements, and the process of disease progression, as well as the key scientific development of the disease condition and multiple signaling pathways and enumerating the most current advancements in discovering new rheumatoid arthritis signaling pathways and rheumatoid arthritis inhibitors. This review emphasizes the anti-rheumatoid effects of these inhibitors [for the Wnt/β-catenin, Phosphoinositide 3-Kinases (PI3K/AKT), Spleen Tyrosine Kinase (SYK), and Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) signaling pathways], illustrating their mechanism of action through a literature search, current therapies, and novel drugs under pre-clinical and clinical trials.