<p>Near-Infrared Laser-Triggered, Self-Immolative Smart Polymersomes for in vivo Cancer Therapy</p>

Abstract

Traditional chemotherapy is accompanied by significant side effects, which, in many aspects, limits its treatment efficacy and clinical applications. Herein, we report an oxidative responsive polymersome nanosystem mediated by near infrared (NIR) light which exhibited the combination effect of photodynamic therapy (PDT) and chemotherapy. Methods: In our study, poly (propylene sulfide) 20-bl-poly (ethylene glycol) 12 (PPS 20-b-PEG 12) block copolymer was synthesized and employed to prepare the polymersome. The hydrophobic photosensitizer zinc phthalocyanine (ZnPc) was loaded in the shell and the hydrophilic doxorubicin hydrochloride (DOX•HCl) in the inner aqueous space of the polymersome. Results: Under the irradiation of 660 nm NIR light, singlet oxygen 1 O 2 molecules were generated from ZnPc to oxidize the neighbouring sulfur atoms on the PPS block which eventually ruptured the intact structure of polymersomes, leading to the release of encapsulated DOX•HCl. The released DOX and the 1 O 2 could achieve a combination effect for cancer therapy if the laser activation and drug release occur at the tumoral sites. In vitro studies confirmed the generation of singlet oxygen and DOX release by NIR irradiation. In vivo studies showed that such a combined PDT-chemotherapy nanosystem could accumulate in A375 tumors efficiently, thus leading to significant inhibition on tumor growth as compared to PDT (PZ group) or chemotherapy alone (DOX group). Conclusion: In summary, this oxidation-sensitive nanosystem showed excellent anti-tumor effects by synergistic chemophotodynamic therapy, indicating that this novel drug delivery strategy could potentially provide a new means for cancer treatments in clinic.

Antimicrobial Photodynamic Therapy: Latest Developments with a Focus on Combinatory Strategies

“…At higher weight fractions, the system tends to form micellar structures [296,362,363]. The hydrophilic and hydrophobic compartments inside the polymersomes enable the uptake and encapsulation of both hydrophobic and hydrophilic molecules [364][365][366][367], making polymersomes a relevant candidate for the development of advanced nanocarriers for PSs [368]. In aPDT and similar approaches, efficient delivery of the PSs to the targeted tissue is essential, not only to minimize toxic side effects and overcome low solubility in body fluids, but also to enable elongated circulation in the blood stream and prevent dimerization and quenching of the PSs.…”

Light-Triggered Polymersome-Based Anticancer Therapeutics Delivery

“…He’s group proposed oxidative-responsive polymersomes mediated by NIR irradiation that exhibited the PDT-chemotherapy combination effect [ 301 ]. For the self-assembly of polymersomes, block copolymer PPS 20 - b -PEG 12 was self-assembled through solvent dispersion.…”

Polymeric Micro/Nanocarriers and Motors for Cargo Transport and Phototriggered Delivery

“…The NIR-P-NPs produced singlet oxygen oxides and sulfur molecules on the polymersome via NIR irradiation at 660 nm, causing their disruption and delivering the doxorubicin. The inhibition of A375 tumor growth using dual therapy proved high efficiency for cancer treatments [232].…”