Self-assembly of porphyrin-grafted lipid into nanoparticles encapsulating doxorubicin for synergistic chemo-photodynamic therapy and fluorescence imaging

Recent Trends of the Bio-Inspired Nanoparticles in Cancer Theranostics

In recent years, various nanomaterials have emerged as an exciting tool in cancer theranostic applications due to their multifunctional property and intrinsic molecular property aiding effective diagnosis, imaging, and successful therapy. However, chemically synthesized nanoparticles have several issues related to the cost, toxicity and effectiveness. In this context, bio-inspired nanoparticles (NPs) held edges over conventionally synthesized nanoparticles due to their low cost, easy synthesis and low toxicity. In this present review article, a detailed overview of the cancer theranostics applications of various bio-inspired has been provided. This includes the recent examples of liposomes, lipid nanoparticles, protein nanoparticles, inorganic nanoparticles, and viral nanoparticles. Finally, challenges and the future scopes of these NPs in cancer therapy and diagnostics applications are highlighted.

Cooperation of endogenous and exogenous reactive oxygen species induced by zinc peroxide nanoparticles to enhance oxidative stress-based cancer therapy

Reactive oxygen species (ROS)-generating anticancer agents can act through two different mechanisms: (i) elevation of endogenous ROS production in mitochondria, or (ii) formation/delivery of exogenous ROS within cells. However, there is a lack of research on the development of ROS-generating nanosystems that combine endogenous and exogenous ROS to enhance oxidative stress-mediated cancer cell death. Methods: A ROS-generating agent based on polymer-modified zinc peroxide nanoparticles (ZnO2 NPs) was presented, which simultaneously delivered exogenous H2O2 and Zn2+ capable of amplifying endogenous ROS production for synergistic cancer therapy. Results: After internalization into tumor cells, ZnO2 NPs underwent decomposition in response to mild acidic pH, resulting in controlled release of H2O2 and Zn2+. Intriguingly, Zn2+ could increase the production of mitochondrial O2·- and H2O2 by inhibiting the electron transport chain, and thus exerted anticancer effect in a synergistic manner with the exogenously released H2O2 to promote cancer cell killing. Furthermore, ZnO2 NPs were doped with manganese via cation exchange, making them an activatable magnetic resonance imaging contrast agent. Conclusion: This study establishes a ZnO2-based theranostic nanoplatform which achieves enhanced oxidative damage to cancer cells by a two-pronged approach of combining endogenous and exogenous ROS.

Enzyme-induced in vivo assembly of gold nanoparticles for imaging-guided synergistic chemo-photothermal therapy of tumor

This article describes a nanoplatform based on matrix metalloproteinase (MMP)-responsive gold nanoparticles (AuNPs) for tumor-targeted photoacoustic (PA) imaging-guided photothermal therapy and drug delivery. AuNPs were grafted with complementary DNA strands, tethered with doxorubicin and coated with poly(ethylene glycol) via a thermal-labile linker and a MMP-cleavable peptide, respectively. The nanoprobes remained well-isolated in healthy tissues, but formed aggregates rapidly under MMP-abundant conditions. The DNA hybridization-induced assembly of the nanoprobes led to prolonged tumor retention and strong near-infrared (NIR) absorption, which is beneficial to deep-tissue imaging and therapy. Compared with MMP-inert nanoprobes, our platform demonstrated significantly enhanced efficiency in PA imaging and photothermal conversion upon NIR irradiation. Meanwhile, doxorubicin could be released rapidly in response to the localized elevation of temperature, leading to synergistic chemo-photothermal therapy. The unique nanoplatform may find applications in effective disease control by delivering imaging and therapy to tumors with high specificity, safety, and universality.

Biodegradable Biomimic Copper/Manganese Silicate Nanospheres for Chemodynamic/Photodynamic Synergistic Therapy with Simultaneous Glutathione Depletion and Hypoxia Relief

The integration of reactive oxygen species (ROS)-involved photodynamic therapy (PDT) and chemodynamic therapy (CDT) holds great promise for enhanced anticancer effects. Herein, we report biodegradable cancer cell membrane-coated mesoporous copper/manganese silicate nanospheres (mCMSNs) with homotypic targeting ability to the cancer cell lines and enhanced ROS generation through singlet oxygen (¹O₂) production and glutathione (GSH)-activated Fenton reaction, showing excellent CDT/PDT synergistic therapeutic effects. We demonstrate that mCMSNs are able to relieve the tumor hypoxia microenvironment by catalytic decomposition of endogenous H₂O₂ to O₂ and further react with O₂ to produce toxic ¹O₂ with a 635 nm laser irradiation. GSH-triggered mCMSNs biodegradation can simultaneously generate Fenton-like Cu⁺ and Mn²⁺ ions and deplete GSH for efficient hydroxyl radical (•OH) production. The specific recognition and homotypic targeting ability to the cancer cells were also revealed. Notably, relieving hypoxia and GSH depletion disrupts the tumor microenvironment (TME) and cellular antioxidant defense system, achieving exceptional cancer-targeting therapeutic effects in vitro and in vivo. The cancer cells growth was significantly inhibited. Moreover, the released Mn²⁺ can also act as an advanced contrast agent for cancer magnetic resonance imaging (MRI). Thus, together with photosensitizers, Fenton agent provider and MRI contrast effects along with the modulating of the TME allow mCMSNs to realize MRI-monitored enhanced CDT/PDT synergistic therapy. It provides a paradigm to rationally design TME-responsive and ROS-involved therapeutic strategies based on a single polymetallic silicate nanomaterial with enhanced anticancer effects.

Incorporation of 7-dehydrocholesterol into liposomes as a simple, universal and efficient way to enhance anticancer activity by combining PDT and photoactivated chemotherapy

Incorporation of 7-dehydrocholesterol instead of cholesterol can efficiently enhance the anticancer activity of photosensitizer-encapsulated liposomes upon irradiation.