Multifunctional polyelectrolyte microcapsules as a contrast agent for photoacoustic imaging in blood

Abstract

The polyelectrolyte microcapsules that can be accurate either visualized in biological media or in tissue would enhance their further in vivo application both as a carrier of active payloads and as a specific sensor. The immobilization of active species, for instance fluorescent dyes, quantum dots, metal nanoparticles, in polymeric shell enables visualization of capsules by optical imaging techniques in aqueous solution. However, for visualization of capsules in complex media an instrument with high contrast modality requires. Herein, we show for the first time photoacoustic imaging (PAI) of multifunctional microcapsules in water and in blood. The microcapsules exhibit greater photoacoustic intensity compare to microparticles with the same composition of polymeric shell presumably their higher thermal expansion. Photoacoustic intensity form microcapsules dispersed in blood displays an enhancement (2-fold) of signal compare to blood. Photoacoustic imaging of microcapsules might contribute to non-invasive carrier visualization and further their in vivo distribution.

Re-assessing the enhanced permeability and retention effect in peripheral arterial disease using radiolabeled long circulating nanoparticles

“…The highest photoacoustic signal was found in the ischemic hindlimb, with minimal background signal found in the pre-injected hindlimb. While endogenous molecules such as hemoglobin and melanin can produce intrinsic PA signal, pre-injection imaging was performed as a control [32, 33]. Additionally, we found positive PA signal in liver sections of mice after receiving an injection of nanoparticles at 3 days post-surgery (Fig.…”

Inorganic/Organic Multilayer Capsule Composition for Improved Functionality and External Triggering

“…It leads to the highest impact of ultrasound on the hydrophobic modified surface in comprising with hydrophilic surface. [132] Nowadays, A number of new approaches for in vivo visualization and treatment using ultrasound such as HIFU [133][134][135] and PA imaging [136,137] are rapidly growing. [129] The hydrophobic surfaces were made using imprinting method, [128] but recently an original approach was demonstrated using consequently adsorption hydrophilic PE molecules and hydrophobic nanoparticles.…”

“…[131] The third approach focuses on the resonance phenomenon that was suggested during last year. [132] Nowadays, A number of new approaches for in vivo visualization and treatment using ultrasound such as HIFU [133][134][135] and PA imaging [136,137] are rapidly growing. HIFU is intensively used now as noninvasive method for cancer therapy.…”

Release from Polyelectrolyte Multilayer Capsules in Solution and on Polymeric Surfaces

“…Another strategy of using microcapsules for theranostics is to explore a polymeric shell as an interrogating surface, for instance in surface enhanced Raman sensing (SERS) [119], [120] and photoacoustic imaging. [121] In SERS approach, molecules either are physically/chemically interacting with plasmonic shell of microcapsules or stand close (few nanometers) to the surface, thus molecules can be spectroscopically recognized both in liquids and in the living cells. [99][100][101][102] Photoacoustic imaging of microcapsules is expected to contribute to non-invasive carrier visualization for delivery of molecules with in vivo distribution as well as specific treatment for the release of a payload.…”