Two‐Photon‐Excited Silica and Organosilica Nanoparticles for Spatiotemporal Cancer Treatment

Abstract

Coherent two-photon-excited (TPE) therapy in the near-infrared (NIR) provides safer cancer treatments than current therapies lacking spatial and temporal selectivities because it is characterized by a 3D spatial resolution of 1 µm and very low scattering. In this review, the principle of TPE and its significance in combination with organosilica nanoparticles (NPs) are introduced and then studies involving the design of pioneering TPE-NIR organosilica nanomaterials are discussed for bioimaging, drug delivery, and photodynamic therapy. Organosilica nanoparticles and their rich and well-established chemistry, tunable composition, porosity, size, and morphology provide ideal platforms for minimal side-effect therapies via TPE-NIR. Mesoporous silica and organosilica nanoparticles endowed with high surface areas can be functionalized to carry hydrophobic and biologically unstable two-photon absorbers for drug delivery and diagnosis. Currently, most light-actuated clinical therapeutic applications with NPs involve photodynamic therapy by singlet oxygen generation, but low photosensitizing efficiencies, tumor resistance, and lack of spatial resolution limit their applicability. On the contrary, higher photosensitizing yields, versatile therapies, and a unique spatial resolution are available with engineered two-photon-sensitive organosilica particles that selectively impact tumors while healthy tissues remain untouched. Patients suffering pathologies such as retinoblastoma, breast, and skin cancers will greatly benefit from TPE-NIR ultrasensitive diagnosis and therapy.

Porphyrin‐based bridged silsesquioxane nanoparticles for targeted two‐photon photodynamic therapy of zebrafish xenografted with human tumor

“…This means that, in these nanoparticles, besides exciting by a monophotonic source of laser, porphyrins were excited with a two‐photon laser with a strong efficiency. Currently, the two‐photon laser excitation in the near infrared region leads to an increased penetration depth in tissues with less photodamages and with a spatiotemporal resolution suitable for small‐sized tumors .…”

“…TPE is very attractive for nanomedicine applications as it allows a deep penetration of the near‐infrared beam down to 2 cm in tissues and a high spatiotemporal resolution presenting a strong interest for imaging and cancer detection. Importantly, TPE‐PDT has demonstrated a high potential for cancer therapy and particularly for small‐sized tumor treatment.…”

Evolving Technologies and Strategies for Combating Antibacterial Resistance in the Advent of the Postantibiotic Era

“…Coherent TPE therapy in NIR has the ability to target the area in a 3D spatiotemporal manner due to its high resolution resulting from low scattering 173. By this way, tumors can both be diagnosed and treated with high accuracy 174…”

“…The use of NP carriers enables stabilization of the PS in the bloodstream and increases of half‐life, both of which lead effective treatment. Among the various types of NP, MSNs have attracted interest for use in TPE‐NIR therapy 171,174. MSNs are used for many purposes from bioimaging, cancer therapy, antibacterial treatment, drug delivery to vaccine delivery.…”

Photocracking Silica: Tuning the Plasmonic Photothermal Degradation of Mesoporous Silica Encapsulating Gold Nanoparticles for Cargo Release

“…Silica can be hybridized using organic and inorganic doping strategies to mediate biodegradability through pH [11,12], enzymatic [12][13][14], redox [3,[15][16][17][18], and biochelation [19][20][21][22] mechanisms [1,2]. The controlled silicon chemistry and hybridization of silica NPs also enables controlled surface modifications for various applications [6,[23][24][25][26][27][28] including drug delivery [6,[29][30][31][32] and medical diagnosis [33][34][35].…”