An MRI‐Sensitive, Non‐Photobleachable Porphysome Photothermal Agent

Abstract

Photothermal therapy makes use of photothermal sensitizers and laser light to thermally ablate diseased tissues. Porphysome nanoparticles offer a nontoxic alternative to inorganic nanocrystals for the efficient conversion of light into heat. Mn(3+) ions were incorporated directly into the building blocks of our porphysome nanoparticles, thus imparting MRI sensitivity while simultaneously improving photostability and maintaining high photothermal efficiency. Mn porphysomes are as photothermally effective as free-base porphysomes and can rival gadolinium diethylenetriaminepentaacetate (Gd-DTPA) for MRI contrast generation. Their MRI contrast generation, photothermal efficiency, and photostability are unprecedented for an all-organic nanoparticle composed of a single functional component.

Plasma membrane activatable polymeric nanotheranostics with self-enhanced light-triggered photosensitizer cellular influx for photodynamic cancer therapy

“…These PS-containing NPs include inorganic NPs [11][12][13][14][15][16][17][18][19][20], quantum dots [21][22][23], liposomes [24][25][26], micelles [27][28][29][30], protein-based NPs [31][32][33][34][35][36], nucleic acid-based NPs [37,38], and porphysomes [39,40]. Besides, many stimuli-responsive polymeric drug carriers have been developed to achieve controlled release of PS molecules and activatable PDT strategy [41][42][43].…”

Rethinking translational nanomedicine: insights from the ‘bottom-up’ design of the Porphysome for guiding the clinical development of imageable nanomaterials

“…Reporting on the MR contrast generation of Mn labelled Pyro-lipid Porphysomes (Mn-Porphysomes), MacDonald et al [42] observed a significant increase in the ionic relaxivity values (2.8-fold for r 1 , 1.8-fold for r 2 ) of structurally dissociated Mn-Porphysomes up to levels comparable with routine MR contrast agent gadolinium diethylenetriamine pentaacetate (Gd-DTPA). The intrinsic structural dependence of the Mn-Porphysome MR signal creates unique opportunities for dissociation-driven MR signal amplification nanomaterials that are presently undergoing proof-of-principle validation in vivo.…”

“…PoP monomers have also been confirmed to strongly chelate paramagnetic manganese(III) (Mn 3+ ) and palladium(II) (Pd 2+ ) for applications in Surface-Enhanced Raman Scattering (SERS)-based imaging [21,22] and Magnetic Resonance (MR) imaging [42 ]. Reporting on the MR contrast generation of Mn labelled Pyro-lipid Porphysomes (Mn-Porphysomes), MacDonald et al [42] observed a significant increase in the ionic relaxivity values (2.8-fold for r 1 , 1.8-fold for r 2 ) of structurally dissociated Mn-Porphysomes up to levels comparable with routine MR contrast agent gadolinium diethylenetriamine pentaacetate (Gd-DTPA).…”

“…However, special attention towards the intended use of the nanomaterial is required since the trade-offs of a highly metalized porphyrin-containing nanomaterial (e.g., for delivering high-payload alpha-particle therapy) are persistently quenched porphyrin fluorescence and limited reactive oxygen species generation [42].…”

Recent advances in the development of organic photothermal nano-agents

“…For example, 64 Cu, a radioisotope, can be simply inserted into porphysomes for positron emission tomography (PET) [60]. In addition, manganese ions can also be incorporated directly into the building blocks of porphysome nanoparticles to enable T1 contrast in magnetic resonance (MR) imaging [61] Porphysomes self-assembled from simple monomers are enzymatically biodegradable and highly biocompatible. Meanwhile, porphysomes can be utilized as efficient nanocarriers as well as imaging probes with many interesting functionalities.…”