Annexin V-Conjugated Mixed Micelles as a Potential Drug Delivery System for Targeted Thrombolysis

Abstract

To alleviate the hemorrhagic side effect of thrombolysis therapy, a thrombus targeted drug delivery system based on the specific affinity of Annexin V to phosphatidylserine exposed on the membrane surface of activated platelet was developed. The amphiphilic and biodegradable biomaterial, polycaprolactone-block-poly(2-(dimethylamino)ethyl methacrylate)-block-poly(2-hydroxyethyl methacrylate) (PCL-b-PDMAEMA-b-PHEMA (PCDH)) triblock polymer, was synthesized via ring opening polymerization (ROP) and atom transfer radical polymerization (ATRP) to use as the nanocarriers of thrombolytic drug. In order to conjugate Annexin V to the polymer, PCDH was modified by succinic anhydride via ring-opening reaction to introduce the carboxyl group (PCDH-COOH). After preparation of PCDH/PCDH-COOH (9/1, m/m) mixed micelles, Annexin V was coupled with the micelles using carbodiimide chemistry. The blood clot lysis assay in vitro confirmed that lumbrokinase-loaded targeted micelles (LKTM) had stronger thrombolysis potency than free lumbrokinase (LK) and LK-loaded nontargeted micelles (LKM, P < 0.05). In vivo thrombolytic assay, multispectral, optoacoustic tomography (MSOT) was used to assess the target ability of LKTM. The results of MSOT images indicated the fluorescence intensity of the LKTM group located in the blood clot position were significantly stronger than the LKM group. A 5 mm of carotid artery containing blood clot was cut out 24 h later after administration to assess the degree of thrombolysis. The results of thrombolytic assay in vivo were consistent with the assay in vitro, which the differences between LK, LKM, and LKTM groups were both statistically significant. All the results of thrombolysis assays above proved that the capacity of thrombolysis in the LKTM group was optimal. It suggested that Annexin V-conjugated micelles will be a potential drug delivery system for targeted thrombolysis.

Smart Delivery of Plasminogen Activators for Efficient Thrombolysis; Recent Trends and Future Perspectives

“…[ 71 ] Annexin V, a protein that specifically binds to PS, has been studied to target nanoparticles to thrombus sites for imaging applications and targeted thrombolysis. [ 72,73 ]…”

Nano-Medicine for Thrombosis: A Precise Diagnosis and Treatment Strategy

“…There are many other polymer-based thrombolytic agent-delivery systems [ 43 , 65 , 66 ]. Colasuonno et al prepared a kind of erythrocyte-inspired discoidal nano-construct using PLGA and PEG, and the unique structure could prevent drug accumulation within the brain and reduce cerebral hemorrhages.…”

Nanomedicines: A Potential Treatment for Blood Disorder Diseases

“…Recently, platelet-targeting peptides- or small molecules-modified micelles/liposomes, shown in Table 3, were reported to deliver thrombolytic drugs to prevent platelet aggregation (Gupta et al, 2005; Yan et al, 2005; Modery et al, 2011). Pan et al developed a Amnexin V-conjugated micelle that was synthesized with biodegradable polymer and loaded with lumbrokinase for phosphatidylserine thrombolysis (Pan et al, 2017). In vitro experiments have shown that such micelles are much more efficient in thrombolysis than the control group.…”