Isolation of pure extracellular vesicles (EVs), especially from blood, has been a major challenge in the field of EV research. The presence of lipoproteins and soluble proteins often hinders the isolation of high purity EVs upon utilization of conventional separation methods. To circumvent such problems, we designed a single-step dual size-exclusion chromatography (dSEC) column for effective isolation of highly pure EVs from bone marrow derived human plasma. With an aim to select appropriate column design parameters, we analyzed the physiochemical properties of the major substances in bone marrow derived plasma, which include EVs, lipoproteins, and soluble proteins. Based on these findings, we devised a novel dSEC column with two different types of porous beads sequentially stacked each other for efficient separation of EVs from other contaminants. The newly developed dSEC columns exhibited better performance in isolating highly pure EVs from AML plasma in comparison to conventional isolation methods.

The lack of drugs that target both disease progression and tissue preservation makes it difficult to effectively manage rheumatoid arthritis (RA). Here, we report a porous silicon-based nanomedicine that efficiently delivers an antirheumatic drug to inflamed synovium while degrading into bone-remodeling products. Methotrexate (MTX) is loaded into the porous silicon nanoparticles using a calcium silicate based condenser chemistry. The calcium silicate–porous silicon nanoparticle constructs (pCaSiNPs) degrade and release the drug preferentially in an inflammatory environment. The biodegradation products of the pCaSiNP drug carrier are orthosilicic acid and calcium ions, which exhibit immunomodulatory and antiresorptive effects. In a mouse model of collagen-induced arthritis, systemically administered MTX-loaded pCaSiNPs accumulate in the inflamed joints and ameliorate the progression of RA at both early and established stages of the disease. The disease state readouts show that the combination is more effective than the monotherapies.