A Microfluidic Co‐Flow Route for Human Serum Albumin‐Drug–Nanoparticle Assembly

Abstract

Nanoparticles are widely studied as carrier vehicles in biological systems because their size readily allows access through cellular membranes. Moreover, they have the potential to carry cargo molecules and as such, these factors make them especially attractive for intravenous drug delivery purposes. Interest in protein‐based nanoparticles has recently gained attraction due to particle biocompatibility and lack of toxicity. However, the production of homogeneous protein nanoparticles with high encapsulation efficiencies, without the need for additional cross‐linking or further engineering of the molecule, remains challenging. Herein, we present a microfluidic 3D co‐flow device to generate human serum albumin/celastrol nanoparticles by co‐flowing an aqueous protein solution with celastrol in ethanol. This microscale co‐flow method resulted in the formation of nanoparticles with a homogeneous size distribution and an average size, which could be tuned from ≈100 nm to 1 μm by modulating the flow rates used. We show that the high stability of the particles stems from the covalent cross‐linking of the naturally present cysteine residues within the particles formed during the assembly step. By choosing optimal flow rates during synthesis an encapsulation efficiency of 75±24 % was achieved. Finally, we show that this approach achieves significantly enhanced solubility of celastrol in the aqueous phase and, crucially, reduced cellular toxicity.

Nanotechnology-Based Celastrol Formulations and Their Therapeutic Applications

“…At these doses, though effective, systemic toxicities including cardiotoxicity (Liu et al, 2019), hepatotoxicity (Jin et al, 2019), and nephrotoxicity (Wu et al, 2018) have been reported, whereas lower doses, though safe, show limited efficacy. To overcome the toxicity issues while achieving the desired therapeutic efficacy, various drug delivery approaches have been investigated that include combination with other chemotherapeutic agents such as afatinib, axitinib, and gefitinib (Zhang et al, 2014;Choi et al, 2016;Gao et al, 2019;Zhao et al, 2019;Dai et al, 2020), combination with traditional Chinese medicines such as betulinic and ellagic acids (An et al, 2015;Duan et al, 2019), overcoming multidrug resistance (Metselaar et al, 2019), nanoparticulate drug delivery systems (Qi et al, 2014;Hakala et al, 2020;, and combination with nucleic acid (Huang et al, 2017). Among these, nanoparticulate drug delivery systems/ nanoformulations of celastrol have been widely reported as a promising strategy to effectively deliver drug at the target site rendering enhanced efficacy and safety.…”

Preparation of Heat-Denatured Macroaggregated Albumin for Biomedical Applications Using a Microfluidics Platform

“…Microfluidics offers an attractive approach to prepare microparticles in a more controlled fashion, as has been demonstrated for many different types of materials . There are several recent descriptions on how to make (drug-loaded) albumin nanoparticles − and microparticles − with microfluidic methods. The microparticles in these reports were stabilized via chemical cross-linking, either by introducing a fixative directly into the albumin-containing droplets formed within the chip or off-chip in a stirred vessel. , Heat has also been reported to stabilize microparticles prepared on a microfluidic device, albeit with proteins other than albumin.…”

Recent progress in nanotechnology-based drug carriers for celastrol delivery

“…Hakala et al 91 utilized a microfluidic co-flow method to generate CLT-loaded HSA nanoparticles with a homogeneous size distribution by adjusting the flow rates. The obtained albumin nanoparticles enhanced the water solubility of CLT and decreased its cellular toxicity.…”